Attachment A - DRAFT-FINAL_2025 Phoenix FMP
City of Phoenix — Transportation, Infrastructure, and Planning Subcommittee (2025-10-15)
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Attachment A
Table of Contents
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
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TABLE OF CONTENTS
Executive Summary ................................................................................................................................................. ES-1
Floodplain Management Planning Overview .................................................................................................. ES-1
The Community Rating System ........................................................................................................................ ES-1
Plan Development Methodology ....................................................................................................................... ES-2
Building the Planning Team ............................................................................................................................... ES-3
Stakeholder Outreach Strategy ......................................................................................................................... ES-4
Stakeholders (* indicates a member of the FMP Committee) ................................................................ ES-4
Risk Assessment ................................................................................................................................................. ES-5
Capability Assessment ....................................................................................................................................... ES-5
Mitigation Strategy .............................................................................................................................................. ES-6
Set Goals ........................................................................................................................................................... ES-6
Mitigation Action Plan ..................................................................................................................................... ES-6
Implementation, Evaluation, and Revision ...................................................................................................... ES-8
1
Introduction and Step 1 Organize .................................................................................................................... 1-1
1.1
Why Prepare This Plan? ............................................................................................................................ 1-1
1.2
Plan Updates ............................................................................................................................................... 1-2
1.2.1
Previous Plans .................................................................................................................................... 1-2
1.2.2
CRS Steps for Floodplain Management Planning........................................................................ 1-2
1.2.3
The Updated Plan - What Has Changed? ...................................................................................... 1-3
1.3
Community Profile ..................................................................................................................................... 1-3
1.3.1
Overview .............................................................................................................................................. 1-3
1.3.2
Physical Setting .................................................................................................................................. 1-5
1.3.3
Population and Demographics ...................................................................................................... 1-11
1.3.4
Land Use ............................................................................................................................................ 1-13
1.3.5
Economy ............................................................................................................................................ 1-17
Step 1: Organize .................................................................................................................................................... 1-18
1.4
Formation of the Planning Teams ........................................................................................................ 1-18
1.4.1
Core Planning Team ........................................................................................................................ 1-18
1.4.2
FMP Committee ............................................................................................................................... 1-18
1.5
Defining the Planning Area ..................................................................................................................... 1-19
1.6
Plan Adoption ............................................................................................................................................ 1-21
1.7
Integration with Planning Programs ..................................................................................................... 1-21
1.8
Continued Public and Stakeholder Involvement ................................................................................. 1-21
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2
Step 2: Involve the Public .................................................................................................................................. 2-1
2.1
FMP Committee ......................................................................................................................................... 2-1
2.2
Stakeholder Coordination and Involvement .......................................................................................... 2-1
2.2.1
Stakeholder Participation ................................................................................................................. 2-1
2.2.2
Pre-Adoption Review ......................................................................................................................... 2-4
2.3
Public Outreach and Input Opportunities ............................................................................................... 2-4
2.3.1
Floodplain Management Plan Webpage ....................................................................................... 2-4
2.3.2
Social Media ........................................................................................................................................ 2-5
2.3.3
Print Media .......................................................................................................................................... 2-5
2.3.4
Public Meeting .................................................................................................................................... 2-5
2.3.5
Neighborhood Association Meeting ............................................................................................... 2-8
2.3.6
Public Survey ....................................................................................................................................... 2-8
3
Step 3: Coordinate .............................................................................................................................................. 3-1
3.1
Review and Incorporation of Existing programs .................................................................................. 3-1
3.1.1
Planning and Regulatory Capability ................................................................................................ 3-1
3.1.2
Administrative and Technical Capabilities .................................................................................. 3-11
3.1.3
Fiscal Capabilities ............................................................................................................................ 3-17
3.1.4
Local Capability Assessment ......................................................................................................... 3-26
3.2
Coordination with Communities and Agencies .................................................................................. 3-37
4
Step 4: Assess the Hazard ................................................................................................................................ 4-1
4.1
What Are The Flood Hazards? ................................................................................................................. 4-1
4.2
Federal Disaster Declarations .................................................................................................................. 4-1
4.3
National Risk Index .................................................................................................................................... 4-2
4.4
Evaluation of Flood Hazards .................................................................................................................... 4-2
4.5
Flood Hazards of Concern for the 2025 Floodplain Management Plan .......................................... 4-3
4.5.1
Changes from the 2021 Maricopa County Multi-jurisdictional Hazard Mitigation Plan ....... 4-4
4.6
Assessing Risk ............................................................................................................................................ 4-4
4.7
Risk Assessment Tools ............................................................................................................................. 4-4
4.7.1
Mapping ............................................................................................................................................... 4-4
4.7.2
Critical Facilities ................................................................................................................................. 4-4
4.7.3
Exposure .............................................................................................................................................. 4-5
4.8
Risk Assessment Approach ..................................................................................................................... 4-6
4.9
Sources of Data Used in Risk Assessment ........................................................................................... 4-6
4.10
Data Limitations ......................................................................................................................................... 4-7
4.11
Flood Hazard Profile .................................................................................................................................. 4-7
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4.11.1
Description of the Hazard ................................................................................................................. 4-7
4.11.2
Location ............................................................................................................................................. 4-11
4.11.3
Extent.................................................................................................................................................. 4-24
4.11.4
Previous Occurrences ..................................................................................................................... 4-29
4.11.5
Probability .......................................................................................................................................... 4-43
4.12
Future Flooding Assessment ................................................................................................................. 4-44
4.13
Other Natural Hazards ............................................................................................................................. 4-44
5
Step 5: Assess the Problem .............................................................................................................................. 5-1
5.1
Vulnerability Assessment ......................................................................................................................... 5-1
5.1.1
Summary of Vulnerability ................................................................................................................. 5-1
5.1.2
Impact on Life, Health, and Safety .................................................................................................. 5-1
5.1.3
Impact on General Building Stock ................................................................................................... 5-3
5.1.4
Impact on Critical Facilities and Infrastructure ............................................................................ 5-4
5.1.5
Impact on the Economy .................................................................................................................... 5-6
5.1.6
Impact on Historic and Cultural Resources .................................................................................. 5-8
5.1.7
Impact on Ecosystems and Natural Resources ........................................................................... 5-8
5.1.8
Impact of Future Population on Flooding ...................................................................................... 5-8
5.1.9
Impact of Development on Flooding .............................................................................................. 5-9
5.1.10
Impact of Climate Change on Future Flooding ............................................................................ 5-9
5.2
Problem Summary ................................................................................................................................... 5-10
6
Step 6: Set Goals ................................................................................................................................................. 6-1
6.1
Previous Goals and Objectives ................................................................................................................ 6-1
6.1.1
Previous FMP Goals .......................................................................................................................... 6-1
6.1.2
Previous FMP Objectives .................................................................................................................. 6-1
6.2
Updated Goals, and Objectives ................................................................................................................ 6-1
6.2.1
2025 FMP Goals ................................................................................................................................. 6-2
7
Step 7: Review Possible Activities ................................................................................................................... 7-1
7.1
Status of Previous Actions ....................................................................................................................... 7-1
7.1.1
2016 City of Phoenix Floodplain Management Plan ................................................................... 7-1
7.1.2
2021 Maricopa County Multi-Jurisdictional Hazard Mitigation Plan ....................................... 7-2
7.2
Catalog of Mitigation Alternatives ........................................................................................................... 7-9
7.3
Preventive Activities ................................................................................................................................. 7-10
7.4
Regulatory Standards Future Outlook .................................................................................................. 7-10
7.5
Property Protection Activities ................................................................................................................ 7-11
7.6
Plan Review Activities .............................................................................................................................. 7-11
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7.7
Emergency Services Activities ............................................................................................................... 7-11
7.8
Structural Project Activities .................................................................................................................... 7-11
7.9
Public Outreach Activities ....................................................................................................................... 7-12
7.10
Funding Capability .................................................................................................................................... 7-12
8
Step 8: Draft an Action Plan .............................................................................................................................. 8-1
8.1
Developing Mitigation Actions ................................................................................................................. 8-1
8.2
Mitigation Action Categorization ............................................................................................................. 8-1
8.2.1
Prevention ............................................................................................................................................ 8-1
8.2.2
Property Protection ............................................................................................................................ 8-1
8.2.3
Natural Resource Protection ............................................................................................................ 8-1
8.2.4
Emergency Services .......................................................................................................................... 8-1
8.2.5
Structural Projects ............................................................................................................................. 8-1
8.2.6
Public Information.............................................................................................................................. 8-1
8.3
Mitigation Actions Selected for the Action Plan ................................................................................... 8-2
9
Step 9: Adopt the Plan........................................................................................................................................ 9-1
10
Step 10: Implement, Evaluate, Revise ....................................................................................................... 10-1
10.1
Incorporation Into Other Planning Mechanisms ................................................................................ 10-1
10.2
Implementing the 2025 FMP Through Existing Programs ............................................................... 10-2
10.3
Monitoring and Evaluating the 2025 FMP ........................................................................................... 10-2
10.4
Ongoing Public Involvement ................................................................................................................... 10-3
10.5
Updating the Plan ..................................................................................................................................... 10-3
APPENDICES
Appendix A. Public Outreach Materials
Appendix B. Stakeholder Outreach Materials
Appendix C. Meeting Documentation
Appendix D. Public Meetings
Appendix E. Progress Report Template
Example Progress Report
Appendix F. Floodplain Management Plan Credit Checklist
Appendix G. Floodplain Management Plan Adoption
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TABLES
Table ES-0-1. Recommended Flood Mitigation Actions ................................................................................... ES-7
Table 1-1. City of Phoenix Population Growth by Decade ................................................................................. 1-11
Table 1-2. Phoenix Metro Area Employment, December 2024 ........................................................................ 1-17
Table 1-3. 2025 FMP Committee Participants .................................................................................................... 1-19
Table 2-1. Federal Agencies and Departments ..................................................................................................... 2-2
Table 2-2. State Agencies and Departments ......................................................................................................... 2-2
Table 2-3. County Agencies and Departments ...................................................................................................... 2-3
Table 2-4. Regional and Local Stakeholders Involved in the Planning Process .............................................. 2-3
Table 2-5. Summary of Federal Planning and Regulatory Capabilities ............................................................ 2-9
Table 3-1. Summary of Federal Planning and Regulatory Capabilities ............................................................ 3-2
Table 3-2. Summary of State Planning and Regulatory Capabilities .............................................................. 3-10
Table 3-3 Summary of County and Regional Planning and Regulatory Capabilities ................................... 3-11
Table 3-4 Summary of Federal Administrative and Technical Capabilities ................................................... 3-12
Table 3-5 Summary of State Administrative and Technical Capabilities ....................................................... 3-15
Table 3-6 Summary of County and Regional Administrative and Technical Capabilities ........................... 3-16
Table 3-7 Summary of Federal Fiscal Capabilities ............................................................................................. 3-17
Table 3-8 Summary of State Fiscal Capabilities ................................................................................................. 3-25
Table 3-9. Planning Capabilities ............................................................................................................................. 3-26
Table 3-10. Emergency Response and Recovery Planning Capabilities ........................................................ 3-28
Table 3-11. Codes, Ordinances, and Regulations Capabilities ......................................................................... 3-29
Table 3-12. Development and Permitting Capabilities ....................................................................................... 3-31
Table 3-13. Departments, Boards, and Committees that Contribute to Flood Risk Reduction .................. 3-31
Table 3-14. Technical/Staffing Capabilities ......................................................................................................... 3-32
Table 3-15. NFIP Floodplain Administration Capabilities .................................................................................. 3-34
Table 3-16. Education and Outreach Capabilities ............................................................................................... 3-35
Table 3-17. Fiscal Capabilities ................................................................................................................................ 3-36
Table 3-18. Community Classifications ................................................................................................................ 3-37
Table 3-19: Community and Agency Participation ............................................................................................. 3-37
Table 4-1. Federal Disaster Declaration Involving Flood in Maricopa County ................................................. 4-2
Table 4-2. Identification of Flood Hazards of Concern for the City of Phoenix, AZ ........................................ 4-3
Table 4-3. Dams Protecting the City of Phoenix ................................................................................................. 4-17
Table 4-4. Levee Systems in the City of Phoenix ................................................................................................ 4-22
Table 4-5. Downstream Hazard Classes for State Regulated Dams .............................................................. 4-26
Table 4-6. State Regulatory Dam Safety Ratings ................................................................................................ 4-26
Table 4-7. Levee Safety Action Classification (LSAC) Table ............................................................................. 4-27
Table 4-8. FEMA Flood Disaster Declarations ..................................................................................................... 4-29
Table 4-9. Recent Flood Hazard Events ................................................................................................................ 4-31
Table 5-1. Population Exposure to High Hazard Flood Zones ........................................................................... 5-1
Table 5-2. Population Exposure Due to Emergency Spillway Inundation ......................................................... 5-2
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Table 5-3. Population Exposure Due to Dam Failure Inundation ....................................................................... 5-2
Table 5-4. Residential Structure Exposure Due to High Hazard Flood Zones ................................................. 5-4
Table 5-5. Residential Structure Exposure Due to Emergency Spillway Inundation ...................................... 5-4
Table 5-6. Residential Structure Exposure Due to Dam Failure Inundation ..................................................... 5-4
Table 5-7. Critical Facilities and Infrastructure Most Likely Impacted by Flood ............................................. 5-5
Table 5-8. Asset Inventory Exposure to High Hazard Flood Zones ................................................................... 5-5
Table 5-9. Asset Inventory Exposure Due to Emergency Spillway Inundation ................................................ 5-6
Table 5-10. Asset Inventory Exposure Due to Dam Failure Inundation ............................................................ 5-6
Table 5-11. National Flood Insurance Program Statistics .................................................................................. 5-8
Table 5-12. Population Projections for the Phoenix Municipal Planning Area ................................................ 5-9
Table 7-1. Actions from the 2016 City of Phoenix Floodplain Management Plan .......................................... 7-1
Table 7-2. Flood Related Mitigation Actions from the 2021 Maricopa County Multi-Jurisdictional Hazard
Mitigation Plan ............................................................................................................................................................. 7-3
Table 7-3. Review of Previous Flood Mitigation Actions ..................................................................................... 7-7
Table 8-1. 2025 Phoenix FMP Action Plan ............................................................................................................. 8-3
FIGURES
Figure 1-1. City of Phoenix Planning Area .............................................................................................................. 1-4
Figure 1-2. Arizona Adjudication Watersheds ....................................................................................................... 1-7
Figure 1-3. Daily Temperatures and Extremes for Phoenix WSFO AP Station, Arizona ................................ 1-8
Figure 1-4. City of Phoenix Surface Waters ......................................................................................................... 1-10
Figure 1-5. CDC/ARSDR Social Vulnerability Index ............................................................................................. 1-11
Figure 1-6. CDC/ARSDR Social Vulnerability Index 2022, Maricopa County, Arizona .................................. 1-12
Figure 1-7. City of Phoenix Land Use and Growth Areas Map ......................................................................... 1-14
Figure 1-8. City of Phoenix Planning Area ............................................................................................................ 1-20
Figure 2-1 City of Phoenix Floodplain Management Website ............................................................................ 2-5
Figure 2-2 Postcard Mailer Advertising Public Meeting ....................................................................................... 2-6
Figure 2-3 Facebook Post Announcing Public Meeting ....................................................................................... 2-7
Figure 2-4 Nextdoor Post Announcing Public Meeting ........................................................................................ 2-7
Figure 2-5 Facebook Post Promoting Public Survey ............................................................................................ 2-8
Figure 4-1 Characteristics of a Floodplain ........................................................................................................... 4-12
Figure 4-2 City of Phoenix Special Flood Hazard Area Map - North ................................................................ 4-13
Figure 4-3 City of Phoenix Special Flood Hazard Area Map - Central ............................................................. 4-14
Figure 4-4 City of Phoenix Special Flood Hazard Area Map - South ............................................................... 4-15
Figure 4-5 Maricopa County Emergency Spillway Flood Hazard Map 1A ...................................................... 4-18
Figure 4-6 Maricopa County Emergency Spillway Flood Hazard Map 1B ...................................................... 4-19
Figure 4-7 Maricopa County Potential Dam Failure Flood Hazard Map 2A ................................................... 4-20
Figure 4-8 Maricopa County Potential Dam Failure Flood Hazard Map 2B ................................................... 4-21
Figure 4-9 Maricopa County Potential Levee Failure Flood Hazard Map 5B ................................................. 4-23
Figure 9-1 City of Phoenix 2025 Floodplain Management Plan Adoption ....................................................... 9-1
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Executive Summary
EXECUTIVE SUMMARY
FLOODPLAIN MANAGEMENT PLANNING OVERVIEW
The City of Phoenix (City) has experienced numerous flooding events that demonstrate how the City can
be significantly impacted by flooding. Even though the City has adopted multiple mitigation and flood
control projects and plans, it is constantly seeking additional ways to reduce flood impacts in the
community.
The responsibility for floodplain management lies with many, including private property owners, business,
industry, and the local, state, and federal government. Recognizing no one solution exists for reducing all
flood hazards, planning provides a mechanism to identify the best alternatives within the capabilities of a
jurisdiction. A floodplain management plan achieves the following in order to set the course for reducing
the risk associated with flooding:
•
Ensuring that all possible floodplain management activities are reviewed and evaluated so that
local problems are addressed by the most appropriate and efficient solutions.
•
Ensuring that floodplain management activities are coordinated with one another and with other
community goals and activities, preventing conflicts and reducing the cost of implementing each
individual activity.
•
Coordinating local floodplain management activities with federal, state, and regional programs.
•
Educating residents on the flooding hazard, loss reduction measures, and the natural and beneficial
functions of floodplains.
•
Building public and political support for mitigation projects.
•
Fulfilling planning requirements for obtaining state or federal assistance.
•
Facilitating the implementation of floodplain management and mitigation activities through an
action plan that has specific tasks, staff assignments, and deadlines.
The City of Phoenix Floodplain Management Plan (FMP) will create an overall strategy of programs,
projects, and mitigation measures that will help the City reduce the adverse impacts of flooding. As a
participant in the National Flood Insurance Program's (NFIP) Community Rating System (CRS), the City
can use the FMP update as a key step toward significant reductions in flood insurance premiums.
THE COMMUNITY RATING SYSTEM
Federal Emergency Management Agency (FEMA’s) CRS program is a voluntary program within the NFIP
that encourages floodplain management activities that exceed the minimum requirements of the NFIP.
The CRS outlines 19 creditable activities that fulfill the program goals of reducing flood losses, facilitating
accurate insurance rating, and promoting awareness of flood insurance. The activities are in four
categories:
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
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Executive Summary
•
Public information;
•
Mapping and regulations;
•
Flood damage reduction; and
•
Warning and response
Flood insurance premiums in participating communities are discounted to reflect the reduced flood risk
resulting from community actions to meet the CRS goals. A Class 1 community receives a 45-percent
premium discount for properties within and outside of a 100-year floodplain, and a Class 9 community
receives a 5-percent discount. Discounts for classifications between those two vary in 5-percent
increments. Class 10 communities do not participate in the CRS; they receive no discount.
The City has participated in the CRS program since 1992 and currently has a Class 5 rating. Eligible NFIP
policyholders are eligible for a 25-percent discount on their flood insurance. To maintain or improve its
rating, the City goes through an annual recertification and a re-verification every three years. The FMP will
help the City maximize its credit potential under the CRS.
PLAN DEVELOPMENT METHODOLOGY
The City’s 2025 Floodplain Management Plan was developed to follow the 10-step process identified by
the CRS Coordinators Manual:
•
Step 1: Organize: This step involved the organization of the planning process. A 17-member
Floodplain Management Plan Committee (FMP Committee), consisting of City staff (7 City
departments represented), citizens (5), and other stakeholders (5), was assembled to oversee the
development of the plan. Additional City departments and other stakeholders participated in less
than 50% of the meetings and were not considered full participants within the FMP Committee.
This committee met five times over a four-month period to provide guidance and oversight to a
Core Planning Team consisting of City Floodplain Management staff and a technical consultant
(Black & Veatch). The Core Planning Team was responsible for the development of the plan with
guidance from the FMP Committee.
•
Step 2: Involve the Public: The planning process included the opportunity for the public to comment
on the plan during its development and before its approval. The FMP Committee was open to the
public, and five different residents were able to attend the meetings and provide input into the
development of the plan. A public survey was posted early in the FMP Committee planning process
to gather feedback and was publicized additionally with neighborhood association and public
meetings, water bill inserts, and social media postings. The FMP Committee developed a public
involvement strategy that was implemented by the planning team and included public meetings
held to provide the public an opportunity to participate in the planning process. Additionally, a City
sponsored website dedicated to the plan
(https://www.phoenix.gov/administration/departments/city-engineer/floodplain-
management/floodplain-management-plan.html) was set up, and multiple media releases were
deployed under the strategy. A fact sheet (see Appendix A) was also developed in both English and
Spanish to help gather additional input and feedback from the public.
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Executive Summary
•
Step 3: Coordinate: This planning step involved incorporating other plans and other agencies’
efforts into the FMP. Coordination with regional, state, and federal agencies involved in flood
hazard mitigation occurred throughout the plan’s development. A capability assessment was
conducted to complete a comprehensive review of existing plans and programs that can support
flood hazard mitigation.
•
Step 4: Assess the Hazard: The City profiled and evaluated the flood hazard to understand the
potential impacts flooding can have on the City’s population, buildings, and infrastructure. The City
looked at their Special Flood Hazard Areas, repetitive loss areas, historically flooded areas, and
other areas of flooding identified in studies and plans.
•
Step 5: Assess the Problem: Once the flood hazard was assessed, the City completed a vulnerability
assessment for flooding to identify the impacts flooding can have on the City’s population,
buildings, and infrastructure. This assessment included measuring potential loss of life, personal
injury, economic injury, and property damage from flood hazards.
•
Step 6: Set Goals: The FMP Committee developed goals to set the context for the subsequent
review of floodplain management activities and drafting of the action plan. These goals were
developed to be consistent with other community goals.
•
Step 7: Review Possible Activities: The FMP Committee reviewed different activities that could
mitigate or reduce the severity of the problems identified in Step 5. The review included a wide
range of activities to ensure that all possible measures were explored, not just the traditional
approaches of flood control, acquisition, and regulation of land use.
•
Step 8: Draft an Action Plan: The FMP Committee selected and specified the activities appropriate
to the City’s resources, hazards, and vulnerable properties. The FMP Committee aimed to create a
balanced program, using numerous categories of potential actions.
•
Step 9: Adopt the Plan: A pre-adoption review draft of the plan was sent for review and comment
to the Insurance Services Office (ISO), the contractor for the CRS. After the ISO granted pre-
adoption approval, the City Council adopted the final plan.
•
Step 10: Implement, Evaluate, Revise: The FMP Committee developed implementation and
maintenance procedures for ensuring that the plan remains an active and relevant document. The
maintenance process includes a schedule for monitoring and evaluating the plan’s progress
annually and revising it every five years. Implementation and maintenance include continued public
involvement and incorporation of the recommendations of this plan into other planning
mechanisms of the City, such as the general plan, capital improvement program, and hazard
mitigation plan.
BUILDING THE PLANNING TEAM
The City brought together a diverse and inclusive group of individuals to participate, develop, and
implement the FMP. A Core Planning Team and FMP Committee oversaw the planning process and were
responsible for coordinating, overseeing, and executing the planning process.
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Executive Summary
CORE PLANNING TEAM
FLOODPLAIN MANAGEMENT
PLAN COMMITTEE
The Core Planning Team was made up of
key personnel from the City and the City’s
contract consultant (Black & Veatch).
The FMP Committee consisted of a
variety of personnel from City
departments along with outside
agencies, non-governmental
organizations, stakeholders, and City
residents that guided the City through
the process of updating the FMP.
STAKEHOLDER OUTREACH STRATEGY
The outreach strategy for the FMP included a City-sponsored webpage dedicated to the FMP
(https://www.phoenix.gov/administration/departments/city-engineer/floodplain-
management/floodplain-management-plan.html), a flood preparedness/hazard mitigation survey,
meetings open to the public, a variety of outreach materials including social media posts and flyers, and
the involvement of the public and stakeholders throughout the planning process.
Stakeholders (* indicates a member of the FMP Committee)
Members of the Core Planning Team were able to meet with 12 different stakeholders from agencies or
non-governmental organizations that operate with or within the City. This included members of the FMP
Committee and others who were not participants during the planning process.
•
Maricopa Department of Transportation (MCDOT)
•
City of Scottsdale
•
Town of Paradise Valley
•
Central Arizona Conservation Alliance (CAZCA)
•
Arizona Forward
•
AZ Stormwater Outreach for Regional Municipalities (AZSTORM)
•
Arizona Department of Transportation (ADOT)*
•
Arizona Department of Water Resources (ADWR)*
•
Arizona State Land Department (ASLD)*
•
Flood Control District of Maricopa County (FCDMC)*
•
Maricopa County Department of Emergency Management (MCDEM)*
•
National Weather Service (NWS)*
Details of the meetings that were held to gather additional information are provided within Section 3 and
within Appendix C.
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Executive Summary
RISK ASSESSMENT
The risk assessment is the process of measuring the potential loss of life, personal injury, economic
impacts, and property damage resulting from natural hazards, like flooding. It allows emergency
management personnel to establish early response priorities by identifying potential hazards and
vulnerable assets. The risk assessment for this plan was developed using information from the following
plans:
•
State of Arizona Hazard Mitigation Plan, 2023.
•
Maricopa County Multi-Jurisdictional Hazard Mitigation Plan, 2021.
o
Used by the City during most recent CRS verification visit for Activity 510 credit.
•
2020 Floodplain Management Plan for Unincorporated Maricopa County.
Some key findings from the risk assessment of this plan are as follows:
•
Between 1966 and 2024, Maricopa County, including the City of Phoenix, was included in 11 flood-
related federal disaster declarations. This equates to a significant flood event, resulting in a federal
disaster declaration, every 5.36 years over a period of 58 years for Maricopa County.
•
34,577 people (2.21% of the City population) are located in high hazard flood zones in the City of
Phoenix.
•
11,833 residential structures (2.0% of the City’s residential building stock) are located in high hazard
flood zones. These structures account for $3.4 billion in replacement cost value.
•
90,618 of the City of Phoenix’s residential buildings structures (15.35% of the City’s residential
building stock) are exposed to flood control dam emergency spillway inundation.
•
Levees in the City of Phoenix protect 12,528 buildings and 14 critical facilities.
•
There are 3,352 NFIP policies in the City of Phoenix. There have been 1,283 flood claims, resulting
in $8.9 million in payments.
•
Of the 3,352 NFIP policies within the City, 53 of those are identified as repetitive loss properties and
5 are identified as severe repetitive loss properties.
•
An estimated 58 percent of Phoenix residents live in the census blocks that intersect the 1% Special
Flood Hazard Area
CAPABILITY ASSESSMENT
Floodplain management in the City of Phoenix is supported by a variety of capabilities. The 2025 FMP
identified capabilities at the City, county, state, and federal levels that support floodplain management in
the City of Phoenix include planning and regulatory capabilities, administrative and technical capabilities,
and fiscal capabilities.
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Executive Summary
MITIGATION STRATEGY
Set Goals
The FMP Committee identified five different goals for the 2025 FMP. Mitigation actions in the FMP update
were identified that achieved multiple goals.
1. Educate the public, policy makers, and City leaders on stormwater and floodplain management and
risks.
2. Coordinate with other jurisdictions and agencies to mitigate flooding hazards and improve
emergency response.
3. Reduce the danger of flood hazards to people, property, critical infrastructure/facilities, and natural
resources.
4. Establish proactive maintenance and preventative measures for stormwater infrastructure.
5. Utilize public funding in the most effective manner for stormwater and floodplain management.
Mitigation Action Plan
The action plan is a key element of the floodplain management plan. It is through the implementation of
the action plan that the City of Phoenix can strive to improve flood resiliency. The action plan includes an
assessment of the capabilities of the City to implement hazard mitigation actions, a review of alternatives,
and a mitigation strategy matrix and prioritization matrix that identify the following:
•
Description of the action
•
Prioritization
•
Lead implementation department (or departments)
•
Funding sources
•
Timeline for implementation
For the purposes of this document, mitigation actions are defined as activities designed to reduce or
eliminate losses resulting from flooding impacts.
Although one of the driving influences for preparing this plan was the CRS, this plan does not focus solely
on CRS credits. It was essential to the City and the FMP Committee to examine actions that would work
through all phases of emergency management. Some of the actions outlined in this plan fall outside the
CRS credit criteria, and CRS creditability was not the focus of their selection. Rather, the focus was on the
actions’ effectiveness in achieving the goals of the plan and whether they are within the City’s capabilities.
Table ES-1 presents a summary of the hazard mitigation actions identified in the action plan.
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ES-7
Executive Summary
Table ES-0-1. Recommended Flood Mitigation Actions
Action
#
Description
Priority
1
Create an annual stormwater and floodplain management workshop for City leaders,
Councilmembers, and Neighborhood Services to help with stormwater and floodplain
education and outreach hold prior to presentation at the Council Meeting.
Medium
2
Present annually at a City of Phoenix Council Meeting on state of City’s stormwater and
floodplain program.
Low
3
Develop flyers, CRS Annual Outreach Letter, and ongoing updates to the City's Floodplain
webpage for use by the public, City leaders, policy makers, and the City’s Neighborhood
Services department.
Low
4
Post at least five times per year on stormwater, floodplain, or flood insurance related topics
on the City’s social media platforms.
Low
5
Provide stormwater section bi-annually within the City’s water bill for stormwater and
floodplain outreach and education purposes.
Low
6
Attend/Present at four neighborhood associations meetings, festivals, or home & garden
shows per year to provide information to the public on recent, current, and future stormwater
and floodplain projects and the importance of flood insurance if property in floodplain.
Low
7
Place signage at City dams to educate the public of the presence of the structure, the need
for the structure, and risks.
Low
8
Provide annual outreach to repetitive loss areas.
High
9
Continue to participate in local or independent annual dam safety and flood response
exercises and invite other agencies to participate.
High
10
Continue to coordinate with other local and regional agencies for flood warnings and
emergency response.
Medium
11
Have at least one City staff attend a FEMA training/workshop annually for emergency
response or floodplain management.
Medium
12
Coordinate with Arizona Department of Water Resources to establish a network of
Continuously Operating Reference Stations (CORS) throughout the City to provide
overlapping coverage to support increased detail in surveys for development and public
infrastructure projects.
Low
13
Hold an annual in person meeting, and record for a webcast, to provide recommendations for
proper vegetation maintenance and flood preparedness.
High
14
Evaluate the requirement for new developments to preserve natural drainage corridors and
implement Green Stormwater Infrastructure and Low Impact Development.
Low
15
Complete major projects within the current Capital Improvement Program – Paradise Ridge
Drainage Improvements; Drainage Improvements: 20th Street between Winchcomb Drive and
19th Way; Storm Drain Replacement Study; Laveen Flood Mitigation; Hohokam Drainage
Program; 3rd Street and Thomas; 12 ARPA Projects; and Storm Drain Asset Management
and Replacement Program
Medium
16
Identify and map critical infrastructure and facilities within the City of Phoenix (for Internal
City Use Only).
High
17
Evaluate flood risks for critical infrastructure and facilities (for Internal City Use Only).
Medium
18
Provide flood fight materials (sand and bags) at/near critical infrastructure and facilities
based on flood risk (for Internal City Use Only).
Medium
19
Annually update database of critical infrastructure and facilities (for Internal City Use Only).
Medium
20
Establish or Update Emergency Action Plans to address flood response scenarios for City-
owned critical infrastructure and facilities (for Internal City Use Only).
Medium
21
Update Emergency Action Plans notification charts annually for the City’s flood control dams.
High
22
Documentation of maintenance occurring at problematic areas throughout the year,
including cost to complete each occurrence.
Medium
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ES-8
Executive Summary
Action
#
Description
Priority
23
Continue monitoring of self-audit maintenance for drywells installed after 2022 when
guidance was established.
Medium
24
Publicize City’s 311 App and Webpage for reporting maintenance issues.
Medium
25
Publicize a summary of the City’s stormwater maintenance work completed each year
(webpage, social media post, and/or water bill).
Low
26
Continue to evaluate on an annual basis the current stormwater and floodplain requirements,
zoning and subdivision ordinances, guidelines, regulations, codes, design manuals, and land
use plan for updates.
Medium
27
Evaluate and update Building Codes on a routine basis (at least every 5 years).
Medium
28
Develop a publicly facing vegetation maintenance guide for private use for wash corridors,
storm drain inlets and outlets, and stormwater storage basins and provide at outreach events
and on City's website.
Low
29
Evaluate City-owned storm drain infrastructure for maintenance and rehabilitation needs.
High
30
Utilize General Obligation Bond funding to mitigate flooding risks.
High
31
Seek opportunity to apply for grants through state and federal agencies to reduce the burden
on the City for stormwater and floodplain management projects.
High
32
Continue partnership with the Flood Control District of Maricopa County and the Small
Projects Assistance Program.
Medium
IMPLEMENTATION, EVALUATION, AND REVISION
Full implementation of the recommendations of this plan will require time and resources. This plan reflects
an adaptive management approach in that specific recommendations and plan review protocols are
provided to evaluate changes in vulnerability and action plan prioritization after the plan’s adoption. The
true measure of the plan’s success will be its ability to adapt to the ever-changing needs of hazard
mitigation. Funding resources are always evolving, as are programs based on state or federal mandates.
The City of Phoenix’s commitment to proactive floodplain management is evidenced by its participation in
the CRS program and the development of this plan. Its well-established programs and policies have strived
to maintain the flood risk at a steady level without increase. The framework established by this plan will
help maintain this tradition in that it identifies a strategy that maximizes the potential for implementation
based on available and potential resources. It commits the City to pursue actions when the benefits of a
project exceed its costs. These techniques will set the stage for successful implementation of the
recommendations in this plan. The Phoenix City Council assumes responsibility for adopting the
recommendations of this plan and committing City resources toward its implementation as the City’s
budget permits.
The City will commit to an annual review and evaluation of the FMP for progress and revision with the FMP
Committee.
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1
INTRODUCTION AND STEP 1 ORGANIZE
The City of Phoenix prepared this Floodplain Management Plan to better
protect the residents, property, and assets throughout the City from the
effects of flood hazards.
The City of Phoenix recognizes the strategic value of being proactive for residents at risk of flooding and
is preparing this update to the FMP, previously issued in May 2016. This FMP update assess the flood
hazards within the jurisdictional boundaries of the City, while maintaining an objective outlook toward the
coordination with partner cities and agencies for collaborated efforts in reducing flood risk. The FMP
update summarizes the previous completed plan elements, provides a review of progress achieved to date,
and sets a roadmap for future actions to reduce flood risk.
1.1
WHY PREPARE THIS PLAN?
The 2025 City of Phoenix FMP presents measures to mitigate potential flood problems in the City of
Phoenix. The purpose of these measures is to reduce or alleviate the loss of life, personal injury, and
property damage that can result from flooding. They involve long- and short-term strategies such as
planning, policy changes, programs, projects, and other activities to mitigate the impacts of floods. The
2025 FMP identifies resources to help guide and coordinate mitigation activities.
All citizens and businesses of the City of Phoenix are the ultimate beneficiaries of the 2025 FMP.
Participation in development of the 2025 FMP by key stakeholders helped ensure that outcomes will be
mutually beneficial for all affected interests. The responsibility for floodplain management lies with many,
including private property owners, business, industry, and local, state, and federal government. The 2025
FMP’s goals and recommendations can lay groundwork for the development and implementation of local
mitigation activities and partnerships.
Numerous state and federal programs and regulations promote floodplain management planning. Notable
among these are two programs of the Federal Emergency Management Agency (FEMA): the National
Flood Insurance Program (NFIP) and the Community Rating System (CRS). These programs provide
benefits in the form of reduced flood insurance costs for communities that meet minimum requirements
for floodplain management. The City of Phoenix participates in both the NFIP and the CRS. The 2025 FMP
was developed to meet the following objectives:
•
Comply with local, state, and federal requirements for floodplain management planning.
•
Meet requirements allowing the City of Phoenix to enhance its CRS classification.
•
Coordinate existing plans and programs to fund and implement high-priority floodplain
management measures.
•
Create a linkage between the 2025 FMP and established plans of the City of Phoenix so that they
can work together in achieving successful mitigation.
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1.2
PLAN UPDATES
The FMP is a living document that the City of Phoenix uses to reduce vulnerability to flood hazards. It
serves as the groundwork for a jurisdiction’s long-term plan to lessen flooding impacts and establishes a
framework for decision-making to mitigate harm to individuals, assets, and the economy from future flood
disasters. Flood mitigation projects include preventative actions, property protection, natural resource
protection, emergency services, structural projects, and public information. These measures help reduce
vulnerability, allowing the City to bounce back more quickly from disasters.
1.2.1
Previous Plans
The City of Phoenix joined the NFIP on December 4, 1979, and has participated in the CRS since October
1, 1992. Floodplain management planning and implementation are principal activities of the City’s
compliance with the CRS. In December 1992, the City Council adopted the City’s first floodplain
management plan. That plan identified the City’s flood-prone areas and established goals, objectives,
policies, and programs to reduce flood related hazards and protect the natural and beneficial functions of
the City’s floodplains.
The original floodplain management plan was updated in May 2016. The original FMP identified 18 citywide
activities to be implemented. The 2021 Maricopa County Multi-Jurisdictional Hazard Mitigation Plan
served as the 5-year update to the 2016 FMP. The City of Phoenix included 20 mitigation actions to be
implemented.
1.2.2
CRS Steps for Floodplain Management Planning
The 2025 FMP has been developed and updated to follow FEMA’s guidelines for flood planning under the
CRS program. Developing and maintaining a comprehensive floodplain management plan is among the
activities that earn CRS credits towards increased flood insurance discounts. To earn CRS credit for a
floodplain management plan, the community’s process for developing the plan must include at least one
item from each of 10 steps (see Appendix F for details):
•
Planning process steps:
o Step 1, Organize
o Step 2, Involve the public
o Step 3, Coordinate
•
Risk assessment steps:
o Step 4, Assess the hazard
o Step 5, Assess the problem
•
Mitigation strategy steps:
o Step 6, Set goals
o Step 7, Review possible activities
o Step 8, Draft an action plan
•
Plan maintenance steps:
o Step 9, Adopt the plan
o Step 10, Implement, evaluate and revise.
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1.2.3
The Updated Plan - What Has Changed?
The overall planning process and plan have been improved and revised for the 2025 FMP. Key changes
are outlined as follows:
•
Best available data, recent flood event occurrences, and updated capabilities have been
incorporated.
•
Proposed mitigation strategies have been updated to reflect new actions or updated details on
previously identified actions.
•
Climate change considerations have been incorporated into the flood profiles instead of as a stand-
alone section.
1.3
COMMUNITY PROFILE
1.3.1
Overview
The City of Phoenix, located in the heart of the greater metropolitan area, dominates the political, economic,
and cultural landscape not only of Maricopa County but also much of Arizona. In 1867, Phoenix founder
Jack Swilling formed a canal company and diverted water from the Salt River, helping to capitalize on the
region’s agricultural value. In 1911, the Roosevelt Dam was completed, and water supplies— vital to growth
in the region—were stabilized. Strong growth in the region began during World War II when several military
airfields were constructed in Maricopa County, and various defense industries followed. Formally
incorporated in 1881, today the City of Phoenix includes over 500 square miles and is the nation’s fifth
most populous city. Phoenix is Arizona’s capitol and is located in the County Seat (Maricopa County 2021).
The City of Phoenix is a pioneer in environmental stewardship. Flagship projects, including the Tres Rios
Wetlands, Energize Phoenix program, the Rio Salado riparian restoration project, and numerous water
conservation efforts, have won the city many awards (City of Phoenix 2015).
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Figure 1-1. City of Phoenix Planning Area
Source: (Phoenix 2024)
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1.3.1.1
Historical Overview
Hundreds of years before any of the cities in the eastern part of the country were so much as clearings in
the wilderness, a well-established, civilized community occupied the land we know as Phoenix between
700 A.D. and 1400 A.D. Those former residents were industrious, enterprising, and imaginative. They built
an irrigation system, consisting mostly of some 135 miles of canals, and the land became fertile. The
ultimate fate of this ancient society, however, is a mystery. The accepted belief is that it was destroyed by
a prolonged drought. Roving Indians, observing the S’edav Va’aki ruins and the vast canal system these
people left behind, gave them the name "Ho Ho Kam" -- the people who have gone (City of Phoenix n.d.).
At the turn of the twentieth century, Phoenix was an oasis with lush trees sprouting tall along wide canal
banks that crisscrossed Phoenix and its suburbs. In fact, Phoenix was once called – A city of gardens and
trees. As Phoenix experienced an explosion of growth after World War II, much of the oasis was
transformed into subdivisions, retail stores and employment opportunities. Some of the early components,
like the Murphy Bridle Path in north central Phoenix, serve as a reminder of Phoenix’s beginnings (City of
Phoenix 2015).
While Phoenix continued to see significant growth after the 1950s, the desire to preserve and incorporate
the beautiful desert setting was a priority for Phoenicians. As a result, in 1972 the City Council established
the Phoenix Mountain Preserve system, which at the time included North Mountain, Shaw Butte and
Dreamy Draw totaling 7,500 acres. Today, Phoenix’s mountain and desert preserves total more than 35,000
acres (City of Phoenix 2015).
1.3.2
Physical Setting
This section describes the geography, land use, and land cover of the City of Phoenix.
1.3.2.1
Location
Phoenix has grown more north-south than east-west since its inception. Over the last decade, Phoenix has
continued to grow outward, with its city limits now encompassing more than 519 square miles (City of
Phoenix 2015). To the south, Phoenix is bounded by the Gila River Indian Community, and on the north by
unincorporated Maricopa County. Many smaller communities, including Tempe, Paradise Valley, and
Scottsdale, define the city to the east, and Peoria and Glendale form the city’s western border. The primary
roadway network includes Interstates 17 and 10, with State Highway 51 and the Loop 101 and 202
(Maricopa County 2021).
1.3.2.2
Geography and Topography
The natural environment of Phoenix is typical of the Sonoran Desert climate. Rugged urban mountain
parks, including South Mountain—one of the nation’s largest urban parks—and the Phoenix Mountain
Preserve create a memorable skyline. The region’s catalyst, the Salt River, now runs dry through the center
of the city, and is complemented by various smaller watersheds (Maricopa County 2021).
The overall topography of the City is flat allowing the City’s main streets to run on a precise grid with wide,
open space roadways. There are mountains located within and around the City. Low mountains
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surrounding the valley are comprised of Phoenix Mountains, South Mountain, McDowell Mountains, White
Tank Mountains, Superstition Mountains, New River Mountains, and Sierra Estrella Mountains.
The predominant soil type in Phoenix is desert loam, a composition of sand, silt, and clay with a distinctive
arid character. These soils have evolved to thrive in the desert climate, exhibiting excellent drainage
properties and low water retention (Alluvial Soil Lab 2025).
1.3.2.3
Watersheds and Surface Waters
A watershed is a geographical area that directs precipitation and snowmelt towards creeks, streams, rivers,
and ultimately outflow locations such as reservoirs, bays, and the ocean. Watersheds vary in size and
configuration, encompassing anything from a small body of water or county to vast regions covering
thousands of square miles with numerous waterways (National Ocean Service 2024).
The City of Phoenix is located in the Gila River System watershed, which includes the Salt and Verde Rivers
(See Figure 1-2 and Figure 1-4). The Gila River provides about 40% of the water supply for the Phoenix
metropolitan area (Feller, J. M. 2007). The watershed of the Salt and Verde Rivers is impounded behind the
dams of the Salt River Project.
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Figure 1-2. Arizona Adjudication Watersheds
Source: (Arizona Department of Water Resources n.d.)
The Central Arizona Project canal which brings water from the Colorado River can supply more than a fifth
of the total water for Maricopa County. In addition to this supply, the metropolitan area is situated over a
prolific aquifer. To assure an adequate water supply for future generations, the state legislature adopted
the Groundwater Management Act in 1980. This act requires careful water management and conservation
measures to ensure water will be available for the influx of people expected in the next 20 years and beyond
(Maricopa County 2021).
Rivers and washes that flow throughout Phoenix are an important part of the desert landscape. Rivers and
washes provide for habitat areas, wildlife corridors and support the ecosystem through continued natural
drainage and flows (City of Phoenix 2015).
Today, Phoenix is home to more than 181 miles of canals. Beyond delivering Phoenix’s most precious
resource, water, throughout the city, the canals have the potential to serve as a catalyst for “elevating the
Phoenix metropolitan region into the ranks of one of the most livable cities.” There is no other city in the
world with a resource so uniquely tied to its past that provides such possibilities for its future. Second only
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to the City’s street network, the hundreds of miles of canal banks provide a tremendous service in giving
the opportunity for residents to cut across Phoenix’s vast urban and desert landscape without the use of
an automobile. The canals represent a multimodal infrastructure that no other city in the world can lay
claim to (City of Phoenix 2015).
1.3.2.4
Climate
The climate in City of Phoenix is characterized by the mild winters and hot summers typical of the upper
Sonoran Desert regions. Temperatures and precipitation across Maricopa County vary somewhat due to
the changes in elevation and orographic influences of local mountains and valleys. The average annual
temperature for the City of Phoenix is 74.2 degrees Fahrenheit (°F) (Maricopa County 2021) and has
approximately 334 days of sunshine each year (City of Phoenix 2015).
Figure 1-3. Daily Temperatures and Extremes for Phoenix WSFO AP Station, Arizona
Source: (Western Regional Climate Center 2013)
The City averages over 330 days of sunshine per year and receives little rainfall. The average annual rainfall
total at Phoenix Sky Harbor International Airport is around 7 inches. Precipitation is sparse during most of
the year, but the monsoon brings an influx of moisture. Historically, the monsoon officially starts when the
average dew point is 55 degrees Fahrenheit for three days in a row; on average this event occurs around
July 7. However, in 2008, the National Weather Service decreed that from that point forward, June 15 would
be the official first day of the monsoon, and it would end on September 30. The monsoon raises humidity
levels and can cause heavy localized precipitation, occasional flooding, large hail, strong winds, the rare
tornado, and dust storms which can rise to the level of a "haboob” in some years.
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July is the wettest month of the year (1.05 inches), while June is the driest (0.02 inches). On September 8,
2014, the City recorded its single highest rainfall total by the National Weather Service with a total of 3.30
inches. The total rainfall on this day broke the 75-year-old previous record of 2.91 inches, set back on
September 4, 1939. This storm was created from the remnants of Hurricane Norbert that had moved up
from the Gulf of California and turned the City’s major interstates and low-lying roadways into ponds,
stranding hundreds of motorists.
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Figure 1-4. City of Phoenix Surface Waters
Source: (Phoenix 2024)
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1.3.3
Population and Demographics
Those that live in the City are one of the most important assets and this FMP will assess risk to people and
identify mitigation strategies to protect them, including underserved and socially vulnerable populations.
1.3.3.1
General Population
Population totals from the previous 2020 U.S. Census, the 2024 American Community Survey, and
projections for 2030 are summarized in Table 1-1 (Maricopa County 2021).
Table 1-1. City of Phoenix Population Growth by Decade
1970
1980
1990
2000
2010
2020
2024
2030
584,303
789,704
983,392
1,321,045
1,445,632
1,608,139
1,650,070
1,816,200
Source: (Maricopa County 2021); (U.S. Census 2025)
1.3.3.2
Vulnerable Populations
Underserved communities are populations sharing a particular characteristic, as well as geographic
communities, which have been systematically denied a full opportunity to participate in aspects of
economic, social, and civic life. Social vulnerability is the potential for loss within an individual or social
group. The term recognizes that some traits influence an individual’s or group’s resilience. This is their
ability to prepare, respond, cope, or recover from an event (FEMA 2023).
Although efforts continue to address underserved and socially vulnerable populations, disparities continue
to exist within the City. These
demographics may be more at-risk
during flood events due to a variety
of factors, such as their physical
and financial capacity to react or
respond effectively, as well as the
location
and
quality
of
their
housing.
Those
with
greater
vulnerability may experience more
severe
impacts
during
emergencies or disasters. It is
essential for public officials to
consider the distinct needs of
vulnerable populations in order to
ensure their safety.
1.3.3.3
Social Vulnerability
Index
The Centers for Disease Control
and Prevention (CDC) and Agency
for Toxic Substances and Disease
Registry
(ATSDR)
Social
Vulnerability Index (SVI) is a place-based index, database, and mapping application designed to identify
Source: (CDC/ATSDR 2024)
Figure 1-5. CDC/ARSDR Social Vulnerability Index
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and quantify communities experiencing social vulnerability. The current CDC/ATSDR Social Vulnerability
Index uses 16 U.S. census variables from the 5-year American Community Survey (ACS) to identify
communities that may need support before, during, or after disasters. The factors include economic data
as well as data regarding education, family characteristics, housing, language ability, ethnicity, and vehicle
access. These variables are combined into a single measure of overall social vulnerability (CDC/ATSDR
2024). FEMA integrates the CDC/ATSDR Social Vulnerability Index into its National Risk Index (NRI)
dataset.
The CDC/ATSDR Social Vulnerability Index 2022 for Maricopa County indicates a high degree of overall
social vulnerability can be found in numerous locations in the City of Phoenix (CDC/ATSDR 2022). The
Maricopa County data is used since the CDC data does not go to a municipal level.
Figure 1-6. CDC/ARSDR Social Vulnerability Index 2022, Maricopa County, Arizona
Source: (CDC/ATSDR 2022)
Notes:
3One or more variables unavailable at census tract level.
Notes:
5Socioeconomic Status: Below 150% Poverty, Unemployed, Housing Costs Burden, No High School Diploma, No Health
Insurance. 6Household Characteristics: Aged 65 and Older, Aged 17 and Younger, Civilian with a Disability, Single-Parent Household,
English Language Proficiency. 7Race/Ethnicity: Hispanic or Latino (of any race); Black and African American, Not Hispanic or Latino;
American Indian and Alaska Native, Not Hispanic or Latino; Asian, Not Hispanic or Latino; Native Hawaiian and Other Pacific Islander,
Not Hispanic or Latino; Two or More Races, Not Hispanic or Latino; Other Races, Not Hispanic or Latino. 8Housing
Type/Transportation: Multi-Unit Structures, Mobile Homes, Crowding, No Vehicle, Group Quarters.
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1.3.4
Land Use
Land use describes the human use of land. It represents the economic and cultural activities (e.g.,
agricultural, residential, industrial, mining, and recreational uses) that are practiced at a given place. Public
and private lands frequently represent very different uses (U.S. EPA 2024).
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Figure 1-7. City of Phoenix Land Use and Growth Areas Map
Source: (Phoenix 2024)
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There is a significant amount of land in mostly small vacant parcels and larger, underutilized parcels that
could be developed or redeveloped within the central villages. Development and redevelopment of this land
is hampered by high land costs, potential environmental contamination, costs to relocate utilities,
surrounding blight, difficulties in assembling parcels, crime and perceptions of crime, and/or concerns
about the school systems. The city has provided incentives for developing these areas, through
redevelopment area programs and a broader area single-family infill housing program (City of Phoenix
2015).
The City of Phoenix Planning and Development Department tracks development trends over the past five
years. The most prominent development trends include (Maricopa County 2021):
•
Strong growth within the Infill Development District: The City of Phoenix's Infill Development District
was created on January 1, 2014. The Infill Development District and associated policies remove
some of the barriers to infill development. The goal is to promote growth and development in areas
served by light rail and existing public infrastructure. In the last decade, high-rise and luxury
apartment projects have fueled a construction boom in central Phoenix.
•
An increasing population in the central core has led to increased investment in the service and
entertainment business environment. Downtown’s Roosevelt Row planning district was named one
of the nation’s best planning concept neighborhoods in 2015 by the American Planning
Association. An abundance of nightlife, restaurants, and trendy apartment complexes turned this
relatively quiet neighborhood into an entertainment destination. Similarly, the Central Ave core in
Midtown and Uptown Phoenix has seen significant capital investments in retail, service
establishments and housing. The Park Central mall and Uptown Plaza have undergone major
renovations, greatly increasing patronage, interest, and investment.
•
Bio-medical and academic expansion: The Arizona State University downtown campus has grown
significantly since its creation in 2006. The downtown campus has over 11,000 students with an
emphasis on Journalism & Mass Communications and Medical, Nursing & Health Innovations. As
part of that medical initiative, the University of Arizona has partnered with Arizona State University
for the Phoenix Biomedical Campus, taking advantage of the Phoenix Downtown Code Biomedical
district zoning entitlements. A few miles away at Midtowns Park Central Mall, the Creighton
University School of Medicine has been completed. The new nine-story,180,000-square-foot
campus will educate nearly 1,000 students annually. Located just a few hundred yards away from
the Creighton campus, the Barrow Neurological Institute is currently in the process of a major
neurology and brain study facility expansion at Dignity Health St Joseph’s hospital. The new
130,050-square-foot, five story building will bring cutting edge technology research and medical
innovation for the study of brain injury, stroke, and dementia.
•
In northeast Phoenix, Mayo clinic is in the middle of a major campus expansion. The $650 million
expansion will double the size of the facilities and add 1.4 million square feet of building space. The
HonorHealth Sonoran Crossing Medical Center is currently under construction in northwest
Phoenix on Dove Valley Rd and interstate 17. This 210,00-square-foot medical center will
accommodate growing health and wellness needs of north Phoenix and Anthem residents.
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•
In west Phoenix, Grand Canyon University is experiencing unprecedented growth in student body,
land acquisition and infrastructure construction. Due to increased student enrollments, the on-
campus student population is currently 19,000. Student population projections at campus buildout
are estimated to be 30,000 students. Over $1.2 billion in infrastructure projects and new programs
are planned and being implemented.
•
In 2020, Taiwan Semiconductor Manufacturing Company (TSMC) Arizona chose Phoenix for its
first advanced U.S. semiconductor manufacturing site — a milestone investment that has
expanded from $12 billion to $165 billion – representing the largest foreign direct investment in a
greenfield project in American history. Plans include six semiconductor wafer fabs, two advanced
packaging facilities and an R&D team center. High-volume production on N4 process technology
started in Q4 2024. In April 2025, TSMC broke ground on the site of the third fab, slated for N2 and
A16 process technologies with volume production expected by the end of the decade. It is expected
that development of computing and AI technologies will continue to take place in the Phoenix metro
area (TSMC 2025).
1.3.4.1
Residential
There has been moderate residential construction growth in the southwest growth region. Single family
and, increasingly multifamily residential units are reacting to the opening of the Loop 202 South Mountain
Freeway and this region is seeing the highest level of single-family development. Southeast Phoenix is
nearing build out and has only seen modest growth activity. Northern Phoenix contains the most
developable land and will likely take many decades to build out. Most of the property in that area is owned
by the State Land Trust and development of land for residential and commercial purposes tends to take
place at slower pace due to a complex disposition process. Those areas are also affected by several
constraints associated with topography, infrastructure requirements, and the regulatory environment that
have made development more challenging. However, the City is working with the State Land Department
to address many of these issues, and it is possible that a significant amount of urban growth will take place
in remaining vacant lands in the north in the coming decade.
Residential growth will continue in the traditional growth areas. Southwest Phoenix will continue to see the
most residential development.
1.3.4.2
Vacant
The current trend of urban infill is expected to continue for the foreseeable future. A decreasing availability
of vacant properties has led to the repurposing of existing, under-utilized properties. City staff continues
to work with developers, investment groups, the historic preservation community and concerned citizens
to strike the most appropriate balance between growth, livability, and the City’s history. The continued
growth of high-rise residential units is anticipated to slow down, at least in the immediate future. The
majority of previous multifamily projects in the infill district in recent years have been rental units. It is
anticipated that more owner-occupied units will be planned as inventory has dwindled under recent market
conditions.
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1.3.4.3
Transportation
Light rail expansion will continue to drive growth in the Infill incentive district and beyond. Construction of
the light rail for the south-central corridor has recently been completed. Service, retail, and multi-family
projects are expected now that the line has been finished. Further light rail extensions to the north and
west are planned. Major redevelopment and renovations are planned to revitalize the Metro center mall
district. A major transportation hub has been planned and will be implemented as the rail line is
constructed.
1.3.4.4
Agriculture
The South Mountain 202 freeway has made thousands of acres of vacant farmland more readily
accessible. An increase in multi-family homes is anticipated. The northern growth areas will likely see
modest growth because of the limited supply of land being brought to market. However, there are a number
of projects being proposed or contemplated by the State Land Department and interest on the part of the
development community is strong, so there may be significantly more activity towards the end of the five-
year period. For example, the Rawhide wash channelization project in northeast Phoenix was recently
completed. A Letter of Map Revision is being submitted to FEMA to have over 2,000 acres of land taken
out of the 100-year floodplain as a result of this project. Growth is anticipated in this area. The State Land
Department is working with the City of Phoenix to release 3,500 acres in northwest Phoenix as part of a
major technology and industrial hub.
There are significant infrastructure requirements to bring this project forward however all parties are
focused on streamlining the critical path. Initial project and infrastructure improvements could start within
the next two years.
1.3.5
Economy
In 2023, the Phoenix Metro Region had a gross metropolitan product of over $398 million (Federal Reserve
Bank of St. Louis n.d.). The largest industries in the City of Phoenix are real estate, financial services, and
manufacturing. Employment by sector in the Phoenix Metro Region is described in Table 1-2. According to
the February 10, 2025, Phoenix Area Economic Summary, the City of Phoenix has an unemployment rate
of roughly 3.2% (Bureau of Labor Statistic 2025).
Table 1-2. Phoenix Metro Area Employment, December 2024
Sector
Total Employees
Mining and logging
4,000
Construction
169,100
Manufacturing
147,200
Trade, transportation, and utilities
499,600
Information
40,900
Financial activities
215,800
Professional and business services
398,200
Education and health services
434,700
Leisure and hospitality
251,300
Other services
78,900
Government
263,700
Source: (Bureau of Labor Statistic 2025)
1 | Introduction and Step 1 Organize
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STEP 1: ORGANIZE
Under Step 1, the City must describe how they organized the overall process in updating the FMP. A
successful planning effort includes active participation and buy-in from the whole community – individuals
and communities, all levels of government, private and non-profit sectors, faith-based organizations, non-
governmental establishments, community lifelines, and members of the public. The 2025 FMP planning
team was made up of a Core Planning Team and FMP Committee.
1.4
FORMATION OF THE PLANNING TEAMS
1.4.1
Core Planning Team
This planning effort was initiated and overseen by the City of Phoenix Floodplain Management Office
(Office of the City Engineer). Black & Veatch Corporation (Black & Veatch) was selected as a contract
consultant to assist the City of Phoenix and its Floodplain Management team through the FMP planning
process. The Core Planning Team was made up of discipline leads from the City’s contract consultant
(Black & Veatch) and key personnel from the City’s Floodplain Management Office. The Core Planning
Team was responsible for the overall coordination of the planning process.
1.4.2
FMP Committee
The FMP Committee was formed to oversee the planning effort to develop the 2025 FMP. Committee
members included City of Phoenix staff, citizens, and other stakeholders. The Core Planning Team
assembled a list of candidates representing interests within the City that could have recommendations for
the plan or be impacted by its recommendations. The Core Planning Team organized the makeup of the
FMP Committee to maximize CRS credit under Step 2 (Involve the Public) of CRS Activity 510. This step
credits a planning process conducted through a planning committee that includes members of the public
and/or non-governmental stakeholders. The Core Planning Team confirmed a committee of 17 members
made up of departments, agencies and residents, as listed in Table 1-3. The makeup of this committee
was 7 City departments and 10 external stakeholders. A detailed list of participants can be found in
Appendix C.
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Table 1-3. 2025 FMP Committee Participants
Jurisdiction / Organization
FMP Meetings
Attended (5 Max)
City Department
External to City
Floodplain Management Office
5
X
Homeland Security & Emergency
Management
4
X
Office of Environmental Programs
5
X
Parks and Recreation
2
X
Planning and Development Department
5
X
Communications Office
2
X
Public Works
1
X
Street Transportation/Dams
5
X
Village Planning Committees
4
X
Water Services
5
X
Resident 1
5
X
Resident 2
5
X
Resident 3
5
X
Resident 4
4
X
Resident 5
5
X
Arizona Department of Transportation
4
X
Arizona Department of Water
Resources
4
X
Arizona State Land Department
5
X
Flood Control District of Maricopa
County
5
X
Maricopa County Department of
Emergency Management
2
X
National Weather Service
4
X
1.5
DEFINING THE PLANNING AREA
The planning area was defined as all areas within the City of Phoenix city limits (see Figure 1-8). This
section provides general information about the City of Phoenix, including its historical information, physical
setting, general building stock, land use, population, demographics, population trends, and community
lifelines. Analyzing this information leads to an understanding of the study area, including economic,
structural, and population assets at risk, and of concerns that could be related to flood hazards analyzed
in this plan (e.g., low-lying areas prone to flooding, high percentage of vulnerable persons in an area).
1 | Introduction and Step 1 Organize
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Figure 1-8. City of Phoenix Planning Area
Source: (Phoenix 2024)
1 | Introduction and Step 1 Organize
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1.6
PLAN ADOPTION
CRS benefits can only be achieved after the Plan is adopted. This plan was submitted for a preadoption
review to FEMA prior to adoption. After pre-adoption was provided, the City of Phoenix will formally adopt
the Plan. Copies of the adoption resolution are provided in Appendix G.
1.7
INTEGRATION WITH PLANNING PROGRAMS
The assessment of capabilities identified areas where floodplain management is currently integrated into
other plans and programs. The assessment looked for opportunities to integrate this FMP with the
legal/regulatory capabilities identified during the capability assessment (Section 3). Capabilities were
identified as integration opportunities if they can support or enhance the actions identified in this plan or
be supported or enhanced by components of this plan. The FMP Committee and City departments
considered actions to implement this integration as described in their jurisdictional annexes.
1.8
CONTINUED PUBLIC AND STAKEHOLDER INVOLVEMENT
The Floodplain Management Plan will be hosted online on the City website. Public and stakeholder input
will be reviewed at the annual review meeting for the plan. Updates to the plan will be publicized.
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2 | Step 2: Involve the Public
2
STEP 2: INVOLVE THE PUBLIC
Public involvement in the 2025 FMP was accomplished in numerous ways, which included:
•
Representation of stakeholders and the public on the FMP Committee
•
Stakeholder coordination and involvement opportunities
•
Public outreach and input opportunities.
Details regarding how the public was involved in the FMP update is described below.
2.1
FMP COMMITTEE
The FMP Committee was formed to oversee the planning effort to develop the 2025 FMP. Committee
members included City of Phoenix staff, citizens, and other stakeholders. The Core Planning Team
assembled a list of candidates representing interests within the City that could have recommendations for
the plan or be impacted by its recommendations. The planning team organized the makeup of the FMP
Committee to maximize CRS credit under Step 2 of CRS Activity 510. This step credits a planning process
conducted through a planning committee that includes members of the public and/or non-governmental
stakeholders. Refer to Section 1.4 and Table 1-3 for a list of representatives on the FMP Committee.
2.2
STAKEHOLDER COORDINATION AND INVOLVEMENT
Opportunities for involvement in the planning process were provided to neighboring communities, local
and regional agencies involved in floodplain management, agencies with authority to regulate
development, businesses, academia, and other private and nonprofit interests (CRS Step 3). The 2025 FMP
incorporates feedback and information from stakeholders as deemed relevant, as referenced within.
Outreach to stakeholders was conducted in a timely manner and maintained throughout the planning
process. This section outlines the stakeholders who were involved in the creation of 2025 FMP and outlines
their participation.
2.2.1
Stakeholder Participation
Stakeholders were invited via email on October 14th, 2025, to participate in the FMP Committee. Each
organization had primary and secondary representatives to attend the five committee meetings held from
January 2025 to April 2025. Those who accepted the invitation actively participated in discussions and
workshops at the committee meetings to support the development of the 2025 FMP. Outside of the
committee meetings, a broader stakeholder outreach was performed with some existing committee
members and newly identified stakeholders to discuss local projects and activities related to stormwater,
flooding and floodplains.
Below is a summary of the stakeholders' involvement in the planning process, demonstrating the extensive
outreach efforts made by the City. For further details on stakeholder involvement, please refer to Appendix
B (Stakeholder Outreach Materials). Key elements of stakeholder outreach include:
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2 | Step 2: Involve the Public
•
Identifying local agencies, residents, and groups for participation
•
Providing online survey to gain public input
•
Developing a Fact Sheet to inform stakeholders
2.2.1.1
Federal Agencies
Table 2-1 describes how federal agencies and departments participated in the 2025 Phoenix FMP. Those
listed in the table below were directly or indirectly involved in the process and provided crucial information
to update the FMP. Refer to Appendix B (Stakeholder Outreach Materials) for further details.
Table 2-1. Federal Agencies and Departments
Agency/Department
Participation
FEMA Region 9
FEMA provided updated planning guidance; provided summary and detailed
NFIP data for the planning area; presented preliminary regulatory flood
products to municipalities and the public; participated in a mitigation strategy
workshop; and conducted plan review
NOAA National Centers for
Environmental Information
(NCEI)
NCEI’s online tools were accessed to obtain information regarding hazard
identification, hazard details, and risk assessments to incorporate into the
FMP.
NOAA National Weather Service
(NWS)
Served on the FMP Committee. Participated in stakeholder outreach
interview.
NOAA Storm Prediction Center
(SPC)
Information accessed to support risk assessment.
U.S. Army Corps of Engineers
(USACE)
Information accessed to support risk assessment including the National
Inventory of Dams and the National Levee Database.
U.S. Census Bureau
Information accessed to support City profile and risk assessment.
U.S. Department of Agriculture
(USDA)
Information accessed to support risk assessment.
U.S. Department of Health and
Human Services (USDHSES)
Information accessed to support risk assessment.
U.S. Environmental Protection
Agency (USEPA)
Information accessed to support risk assessment.
U.S. Geological Survey (USGS)
Information accessed to support risk assessment.
2.2.1.2
State Agencies
Table 2-2 describes how state agencies and departments participated in the 2025 Phoenix FMP update.
Those listed in the table below were directly or indirectly involved in the process and provided crucial
information to update the FMP. Refer to Appendix B (Stakeholder Outreach Materials) for further details.
Table 2-2. State Agencies and Departments
Agency/Department
Participation
Arizona Department of
Emergency and Military Affairs
Invited to participate in stakeholder outreach interview. Provided information
through the 2023 Arizona State Hazard Mitigation Plan.
Arizona Department of Water
Resources
Served on the FMP Committee. Participated in stakeholder outreach
interview.
Arizona State Land Department
Served on the FMP Committee. Participated in stakeholder outreach
interview.
Arizona Department of
Transportation
Served on the FMP Committee. Participated in stakeholder outreach
interview.
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2 | Step 2: Involve the Public
2.2.1.3
County Agencies
Table 2-3 describes how Maricopa County agencies and departments participated in the 2025 Phoenix
FMP update. Those listed in the table below were directly or indirectly involved in the process and provided
crucial information to update the FMP. Refer to Appendix B (Stakeholder Outreach Materials) for further
details.
Table 2-3. County Agencies and Departments
Agency/Department
Participation
Maricopa County Department of
Emergency Management
Served on the FMP Committee. Participated in stakeholder outreach
interview. Provided information through the 2021 Maricopa County Multi-
Jurisdictional Hazard Mitigation Plan.
Flood Control District of
Maricopa County
Served on the FMP Committee. Invited to participate in stakeholder outreach
interview. Provided information through the 2020 Floodplain Management
Plan for Unincorporated Maricopa County.
Maricopa Association of
Governments (MAG)
Invited to participate in stakeholder outreach interview.
Maricopa County Department of
Transportation (MCDOT)
Invited to participate in stakeholder outreach interview.
2.2.1.4
Regional and Local Stakeholders
Five non-governmental stakeholders were invited to participate in the FMP update process and are listed
in the tables below. Of those invited to participate, four stakeholders from four different agencies provided
input in a variety of ways. Those that served on the FMP Committee and those that completed the
stakeholder survey are noted accordingly.
Regional and local stakeholders that participated in the 2025 FMP planning process are described in Table
2-4. Refer to Appendix B (Stakeholder Outreach Materials) for further details.
Table 2-4. Regional and Local Stakeholders Involved in the Planning Process
Agency or Organization Name
Participation
Central Arizona Conservation
Alliance (CAZCA)
Participated in stakeholder outreach interview.
Phoenix Mountains Preservation
Council
Invited to participate in stakeholder outreach interview.
Arizona Forward
Participated in stakeholder outreach interview.
AZ STORM
Participated in stakeholder outreach interview.
Maricopa Audubon Society
Invited to participate on the FMP Committee.
2.2.1.5
Neighboring Communities
Adjacent local jurisdictions were invited to contribute to the 2025 FMP planning process. Neighboring
jurisdictions were invited via email to participate in an outreach interview conducted by the contract
consultant. These interviews were to identify and discuss any recent, ongoing, or future projects or
activities related to stormwater, flooding, or floodplains within or adjacent to the City of Phoenix.
Participants were also given the opportunity to be notified once the Draft Floodplain Management Plan for
the City of Phoenix was ready for stakeholder and public review.
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2 | Step 2: Involve the Public
Table 2-5. Neighboring Communities Involved in the Planning Process
Agency or Organization Name
Participation
City of Scottsdale
Participated in stakeholder outreach interview. The Rawhide Wash Flood
Hazard Mitigation Project was discussed. The City of Phoenix is a part of this
project and has all the relevant data and information needed.
Town of Paradise Valley
Participated in stakeholder outreach interview. Town is currently working
through updates to their Stormwater Master Plan which is anticipated to be
complete June 30, 2025.
2.2.2
Pre-Adoption Review
All the agencies listed above were provided an opportunity to review and comment on this plan, primarily
through the floodplain management plan website. All agencies were sent an e-mail message informing
them that draft portions of the plan were available for review. In addition, the complete draft plan was sent
to the Insurance Services Office, FEMA’s CRS contractor, for a pre-adoption review to ensure CRS program
compliance.
2.3
PUBLIC OUTREACH AND INPUT OPPORTUNITIES
Broad public participation in the planning process helps ensure that diverse points of view about local
needs are considered and addressed. CRS credits are available for providing opportunities to comment on
floodplain management plans during the drafting stages and prior to plan approval, as well as for optional
public involvement activities (CRS Step 2). This section describes the outreach strategy the City
implemented to involve the public throughout the planning process.
2.3.1
Floodplain Management Plan Webpage
The City of Phoenix maintains a Floodplain Management Plan website that was used to keep the public
informed about milestones, public participation opportunities, and to solicit input.
(https://www.phoenix.gov/administration/departments/city-engineer/floodplain-management.html)
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2 | Step 2: Involve the Public
Figure 2-1 City of Phoenix Floodplain Management Website
2.3.2
Social Media
The City used Facebook, NextDoor, Instagram, and X (formerly Twitter) to promote the planning effort,
including the public survey, public comment period, and public meeting. Example posts for the FMP are
provided within Appendix A.
2.3.3
Print Media
A fact sheet has been prepared for public distribution to provide clear and condensed information on the
2025 FMP. It outlines what an FMP is, why it is needed, highlights of the benefits of the plan and the CRS
classification. It also includes a public survey to gather community input and a link directly to the City’s
FMP webpage to provide residents more information on the plan. The FMP Fact Sheet is provided within
Appendix A.
2.3.4
Public Meeting
A public meeting was held virtually to announce the availability of the draft FMP for public review on May
22, 2025. This meeting was advertised on the City’s FMP webpage, fact sheet, social media posts, and
inserts within the water bill. 3,757 postcards were mailed (with English and Spanish translations) and
various social media posts (posted on <ay 11, May 16, and May 20, 2025) were made to promote the
meeting. 44 members of the public registered to attend the meeting.
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2 | Step 2: Involve the Public
Documentation for the public meetings, including the presentation and sign-in sheets, is provided within
Appendix D.
Figure 2-2 Postcard Mailer Advertising Public Meeting
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2 | Step 2: Involve the Public
Figure 2-3 Facebook Post Announcing Public Meeting
Figure 2-4 Nextdoor Post Announcing Public Meeting
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2 | Step 2: Involve the Public
2.3.5
Neighborhood Association Meeting
A public presentation was completed at the South Mountain-Laveen Chamber of Commerce Meeting on
April 23, 2025, to present the FMP planning process and collect information on flood hazards, problems,
and action items to address these hazards and problems. The fact sheet was passed out at the meeting
and attendees were requested to provide feedback through the public survey. 29 members of the public
attended the meeting. The presentation provided during the meeting can be found within Appendix A.
2.3.6
Public Survey
The Core Planning Team developed and posted a public survey at the onset of the planning process. The
survey was designed to capture data and information from members of the public, especially those who
might not be able to attend public meetings or participate through other means in the planning process.
The survey was posted early in the FMP Committee meeting process and was opened through the public
review period. The City posted the survey on the planning website and multiple social media platforms
(Facebook, Instagram, and X), and it was announced at a Phoenix Council meeting, which was also
televised. A link to the electronic public survey was also shared with FMP Committee members and
stakeholders. The City posted on social media platforms on May 21, June 23, June 25, and July 2, 2025 to
gather feedback on the public survey.
Figure 2-5 Facebook Post Promoting Public Survey
2.3.6.1
Summary of Survey Results
A total of 18 survey responses were gathered for the public survey. A total of 10 questions were provided
to gather additional input from the public on floodplains impacts and management within the City. Table
2-5 provides a summary of the questions and responses. Refer to Appendix A for the full output of
responses.
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2 | Step 2: Involve the Public
Table 2-5. Summary of Federal Planning and Regulatory Capabilities
Question
Top Responses (Votes)
What floodplain issues are important to you?
(Select all that apply)
Knowing where flood risk exists (15)
Reducing flood risks (13)
How do you receive information about flooding?
(Select all that apply)
TV/News Station (10)
Website or online sources (6)
What flooding situations have you experienced?
(Select all that apply)
Flooding while driving (11) & Altered route due to street
flooding (11)
Driven through flooded washes to get to destination (5)
Do you have flood insurance?
I don’t know (3)
No, mortgage does not require it (6)
Have you taken steps to reduce the impacts of
flooding on your property and/or prepared for
flooding?
Yes, I have taken steps to reduce damages to my property (8)
No, it doesn’t concern me (3) & No, I don’t know what to do (3)
What steps have been taken in your area or
neighborhood to reduce flood risk?
(Select all that apply)
I don’t know (9)
Constructed improvements (3); Education (3); & Preventative
maintenance (3)
Which of the following activities have you
participated in? (Select all that apply)
Using the Floodplain Viewer to check if your home in in a
FEMA designated floodplain (8)
Education & outreach (5)
3 | Step 3: Coordinate
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3
STEP 3: COORDINATE
3.1
REVIEW AND INCORPORATION OF EXISTING PROGRAMS
The CRS 10-step planning process provides credit for a planning process that includes a review of existing
studies, reports, and technical information and of the community’s needs, goals, and plans for the area
(CRS Step 3a). The review needs to cover community needs and goals, past flood studies, disaster damage
reports, natural area plans, and other documents that will provide information for the planning process.
The City of Phoenix utilized the most current technical information, plans, studies, and reports during the
planning process to assist in hazard profiling, risk and vulnerability assessment, reviewing mitigation
capabilities, and identifying, developing, and prioritizing mitigation strategies.
This chapter identifies existing laws, ordinances, and plans at the federal, state, county/region, and local
level that can support or impact mitigation actions identified in this plan. Each program identified in this
chapter represents a capability that the City has to implement actions identified in Step 8: Draft an Action
Plan
These are ongoing programs leveraged by the City to promote flood resiliency within the planning area.
3.1.1
Planning and Regulatory Capability
Planning and regulatory capabilities are based on the implementation of ordinances, policies, local laws,
state statutes, plans, and programs that relate to guiding and management growth and development.
Planning and regulatory capabilities refer not only to current plans and regulations, but also to the City’s
ability to change and improve those plans and regulations as needed.
Federal Planning and Regulatory Capabilities
Table 3-1 summarizes the planning and regulatory capabilities available to the City of Phoenix at the federal
level.
3 | Step 3: Coordinate
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Table 3-1. Summary of Federal Planning and Regulatory Capabilities
Capability
Details
Americans with
Disabilities
Act
The Americans with Disabilities Act (ADA) seeks to prevent discrimination against
people with disabilities in employment, transportation, public accommodation,
communications, and government activities. Title II of the ADA deals with compliance
with the Act in emergency management and disaster-related programs, services, and
activities. It applies to state and local governments as well as third parties, including
religious entities and private nonprofit organizations.
The ADA has implications for sheltering requirements and public notifications. During
an emergency alert, officials must use a combination of warning methods to ensure
that all residents have all necessary information. Those with hearing impairments may
not hear radio, television, sirens, or other audible alerts, while those with visual
impairments may not see flashing lights or other visual alerts. Two technical
documents for shelter operators address the physical accessibility needs of people
with disabilities, as well as medical needs and service animals.
The ADA intersects with disaster preparedness programs in regard to transportation,
social services, temporary housing, and rebuilding. Persons with disabilities may
require additional assistance in evacuation and transit (e.g., vehicles with wheelchair
lifts or paratransit buses). Evacuation and other response plans should address the
unique needs of residents. Local governments may be interested in implementing a
special-needs registry to identify the home addresses, contact information, and needs
for residents who may require more assistance.
FEMA floodplain management project grant applications require full compliance with
applicable federal acts. Any action identified in this plan that falls within the scope of
this act will need to meet its requirements.
Civil Rights Act of
1964
The Civil Rights Act of 1964 prohibits discrimination based on race, color, religion, sex,
or national origin and requires equal access to public places and employment. The Act
is relevant to floodplain management in that it prohibits local governments from
favoring the needs of one population group over another. Local government and
emergency response must ensure the continued safety and well-being of all residents
equally, to the extent possible. FEMA floodplain management project grant
applications require full compliance with applicable federal acts. Any action identified
in this plan that falls within the scope of this act will need to meet its requirements.
3 | Step 3: Coordinate
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Capability
Details
Clean Water Act
The federal Clean Water Act (CWA) employs regulatory and non-regulatory tools to
reduce direct pollutant discharges into waterways, finance municipal wastewater
treatment facilities, and manage polluted runoff. These tools are employed to achieve
the broader goal of restoring and maintaining the chemical, physical, and biological
integrity of the nation’s surface waters so that they can support “the protection and
propagation of fish, shellfish, and wildlife and recreation in and on the water.”
The evolution of CWA programs over the last decade has included a shift from a
program-by-program, source-by-source, and pollutant-by-pollutant approach to more
holistic watershed-based strategies. Under the watershed approach, equal emphasis is
placed on protecting healthy waters and restoring impaired ones. Numerous issues are
addressed, not just those subject to CWA regulatory authority. Involvement of
stakeholder groups in the development and implementation of strategies for achieving
and maintaining water quality and other environmental goals is a hallmark of this
approach.
Section 404 of the Clean Water Act regulates the discharge of dredged and fill material
into waters of the United States, including wetlands. Responsibility for administering
and enforcing Section 404 is shared by the U.S. Army Corps of Engineers and the EPA.
The Corps administers the day-to-day program, including individual permit decisions
and jurisdictional determinations, develops policy and guidance, and enforces Section
404 provisions. The EPA develops and interprets environmental criteria used in
evaluating permit applications, identifies activities that are exempt from permitting,
reviews/comments on individual permit applications, enforces Section 404 provisions,
and has the authority to veto Corps permit decisions. With EPA approval and oversight,
states and tribes can assume administration of the Section 404 permit program for
certain non-navigable waters, but only two states—Michigan and New Jersey—have
done so.
The CWA is critical to floodplain management in several ways. There are often
permitting requirements for any construction within 200 feet of water of the United
States, which may have implications for implementing floodplain management
projects. Additionally, CWA requirements apply to wetlands, which serve essential
functions related to preserving and protecting the natural and beneficial functions of
floodplains and are linked with a community’s floodplain management program.
Finally, the National Pollutant Discharge Elimination System is part of the CWA and
addresses local stormwater management programs. Stormwater management plays a
critical role in floodplain management by addressing urban drainage or localized
flooding issues within jurisdictions.
FEMA floodplain management project grant applications require full compliance with
applicable federal acts. Any action identified in this plan that falls within the scope of
this act will need to meet its requirements.
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Disaster Mitigation Act
of 2000 (DMA 2000)
P.L. 106-390
The DMA is the current federal legislation addressing hazard mitigation planning. DMA
2000 provides an opportunity for states, tribes, and local governments to take a new
and revitalized approach to mitigation planning. DMA 2000 amended the Robert T.
Stafford Disaster Relief and Emergency Assistance Act (the Act) by repealing the
previous mitigation planning provisions (Section 409) and replacing them with a new
set of mitigation plan requirements (Section 322). This new section emphasizes the
need for state, tribal, and local entities to closely coordinate mitigation planning and
implementation efforts. It emphasizes planning for disasters before they occur. It
specifically addresses planning at the local level, requiring plans to be in place before
Hazard Mitigation Assistance grant funds are available to communities. HMPs
designed to meet the requirements of DMA will remain eligible for future FEMA Hazard
Mitigation Assistance funds. This plan is designed to be integrated with the City’s
Hazard Mitigation Plan which meets the requirements of DMA, improving eligibility for
future hazard mitigation funds.
Endangered Species
Act
The federal Endangered Species Act (ESA) was enacted in 1973 to conserve species
facing depletion or extinction and the ecosystems that support them. The act sets
forth a process for determining which species are threatened and endangered and
requires the conservation of the critical habitat in which those species live. The ESA
provides broad protection for species of fish, wildlife and plants that are listed as
threatened or endangered. Provisions are made for listing species, as well as for
recovery plans and the designation of critical habitat for listed species. The ESA
outlines procedures for federal agencies to follow when taking actions that may
jeopardize listed species and contains exceptions and exemptions. It is the enabling
legislation for the Convention on International Trade in Endangered Species of Wild
Fauna and Flora. Criminal and civil penalties are provided for violations of the ESA and
the Convention.
Federal agencies must seek to conserve endangered and threatened species and use
their authorities in furtherance of the ESA’s purposes. The ESA defines three
fundamental terms:
•
Endangered means that a species of fish, animal, or plant is “in danger of extinction
throughout all or a significant portion of its range.” (For salmon and other vertebrate
species, this may include subspecies and distinct population segments.)
•
Threatened means that a species “is likely to become endangered within the
foreseeable future.”
•
Regulations may be less restrictive for threatened species than for endangered
species.
•
Critical habitat means “specific geographical areas that are…essential for the
conservation and management of a listed species, whether occupied by the species
or not.”
Five sections of the ESA are of critical importance to understanding it:
•
Section 4: Listing of a Species—The National Oceanic and Atmospheric
Administration Fisheries Service (NOAA Fisheries) is responsible for listing marine
species; the U.S. Fish and Wildlife Service (USFWS) is responsible for listing
terrestrial and freshwater aquatic species. The agencies may initiate reviews for
listings, or citizens may petition for them. A listing must be made “solely on the basis
of the best scientific and commercial data available.” After a listing has been
proposed, agencies receive comments and conduct further scientific reviews for 12
to 18 months, after which they must decide if the listing is warranted. Economic
impacts cannot be considered in this decision, but it may include an evaluation of
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the adequacy of local and state protections. Critical habitat for the species may be
designated at the time of listing.
•
Section 7: Consultation—Federal agencies must ensure that any action they
authorize, fund, or carry out is not likely to jeopardize the continued existence of a
listed or proposed species or adversely modify its critical habitat. This includes
private and public actions that require a federal permit. Once a final listing is made,
non-federal actions are subject to the same review, termed a “consultation.” If the
listing agency finds that an action will “take” a species, it must propose mitigations
or “reasonable and prudent” alternatives to the action; if the proponent rejects these,
the action cannot proceed.
•
Section 9: Prohibition of Take—It is unlawful to “take” an endangered species,
including killing or injuring it or modifying its habitat in a way that interferes with
essential behavioral patterns, including breeding, feeding, or sheltering.
•
Section 10: Permitted Take—Through voluntary agreements with the federal
government that provide protections to an endangered species, a non-federal
applicant may commit a take that would otherwise be prohibited as long as it is
incidental to an otherwise lawful activity (such as developing land or building a road).
These agreements often take the form of a “Habitat Conservation Plan.”
•
Section 11: Citizen Lawsuits—Civil actions initiated by any citizen can require the
listing agency to enforce the ESA’s prohibition of taking or to meet the requirements
of the consultation process.
FEMA floodplain management project grant applications require full compliance with
applicable federal acts. Any action identified in this plan that falls within the scope of
this act will need to meet its requirements.
Floodplain
Management and
Protection of Wetlands
(44 CFR Part 9)
This federal code requires federal agencies to avoid long-term and short-term adverse
impacts associated with the occupancy and modification of floodplains.
Code of Federal
Regulations, Standard
State Mitigation
Plans (44 CFR PART
201.4)
FEMA has prepared policies and procedures for FEMA’s review and approval of state
and local emergency all-hazard mitigation plans.
Robert T. Stafford
Disaster Relief and
Emergency Assistance
Act
The Act provides an orderly and continuing means of assistance by the federal
government to state and local governments in carrying out their responsibilities to
alleviate the suffering and damage that results from disasters. The provisions of the
Act include (1) revising and broadening the scope of existing disaster relief programs;
(2) encouraging the development of comprehensive disaster preparedness and
assistance plans, programs, capabilities, and organizations by state and local
governments; (3) achieving greater coordination and responsiveness of disaster
preparedness and relief programs; (4) encouraging individuals, and state and local
governments to protect themselves by obtaining insurance coverage to supplement or
replace governmental assistance; (5) encouraging hazard mitigation measures to
reduce losses from disasters, including development of land-use and construction
regulations; and (6) providing federal assistance programs for both public and private
losses sustained in disasters. From a mitigation perspective of the Act, the Arizona
Department of Emergency and Military Affairs is the lead agency that reviews, submits,
and administers federal funding to programs that mitigate hazards. These programs
help find projects that are cost beneficial to help reduce damages from hazards.
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National Dam Safety
Act
Potential for catastrophic flooding due to dam failures led to passage of the National
Dam Inspection Act in 1972, creation of the National Dam Safety Program in 1996, and
reauthorization of the program through the Dam Safety Act in 2006. In November
2019, FEMA published the Emergency Operations Planning: Dam Incident Planning
Guide supporting state, local, tribal, and territorial emergency managers in planning for
dam incidents and failures. National Dam Safety Program, administered by FEMA
requires a periodic engineering analysis of the majority of dams in the country;
exceptions include the following:
•
Dams under the jurisdiction of the Bureau of Reclamation, Tennessee Valley
Authority, or International Boundary and Water Commission
•
Dams constructed pursuant to licenses issued under the Federal Power Act
•
Dams that the Secretary of the Army determines do not pose any threat to human
life or property.
The goal of this FEMA-monitored effort is to identify and mitigate the risk of dam
failure so as to protect lives and property of the public. The National Dam Safety
Program is a partnership among the states, federal agencies, and other stakeholders
that encourages individual and community responsibility for dam safety. Under FEMA’s
leadership, state assistance funds have allowed all participating states to improve their
programs through increased inspections, emergency action planning, and purchases
of needed equipment. FEMA has also expanded existing and initiated new training
programs. Grant assistance from FEMA provides support for improvement of dam
safety programs that regulate most of the dams in the United States.
National
Environmental Policy
Act
The National Environmental Policy Act requires federal agencies to consider the
environmental impacts of proposed actions and reasonable alternatives to those
actions, alongside technical and economic considerations. The National Environmental
Policy Act established the Council on Environmental Quality, whose regulations (40
CFR Parts 1500-1508) set standards for compliance. Consideration and decision-
making regarding environmental impacts must be documented in an environmental
impact statement or environmental assessment. Environmental impact assessment
requires the evaluation of reasonable alternatives to a proposed action, solicitation of
input from organizations and individuals that could be affected, and an unbiased
presentation of direct, indirect, and cumulative environmental impacts. FEMA
floodplain management project grant applications require full compliance with
applicable federal acts. Any action identified in this plan that falls within the scope of
this act will need to meet its requirements.
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National Flood
Insurance Program
(NFIP)
The National Flood Insurance Program (NFIP) makes federally backed flood insurance
available to homeowners, renters, and business owners in participating communities
that enact floodplain regulations. Participation and good standing under NFIP are
prerequisites to grant funding eligibility under the Robert T. Stafford Act.
For most participating communities, FEMA has prepared a detailed Flood Insurance
Study. The study presents water surface elevations for floods of various magnitudes,
including the 100-year flood and the 500-year flood. Base flood elevations and the
boundaries of the flood hazard areas are shown on Flood Insurance Rate Maps, which
are the principal tools for identifying the extent and location of the flood hazard. Flood
Insurance Rate Maps are the most detailed and consistent data source available, and
for many communities, they represent the minimum area of oversight under the local
floodplain management program. In recent years, Flood Insurance Rate Maps have
been digitized as Digital Flood Insurance Rate Maps, which are more accessible to
residents, local governments, and stakeholders.
Participants in the NFIP must, at a minimum, regulate development in floodplain areas
in accordance with NFIP criteria. Before issuing a permit to build in a floodplain,
participating jurisdictions must ensure that three criteria are met:
•
New buildings and those undergoing substantial improvements must, at a minimum,
be elevated to protect against damage by the 100-year flood.
•
New floodplain development must not aggravate existing flood problems or
increase damage to other properties.
•
New floodplain development must exercise a reasonable and prudent effort to
reduce its adverse impacts on threatened salmonid species.
NFIP Community
Rating System (CRS)
As an additional component of the NFIP, CRS is a voluntary incentive program that
recognizes and encourages community floodplain management activities that exceed
the minimum NFIP requirements. As a result, flood insurance premium rates are
discounted to reflect the reduced flood risk resulting from the community actions
meeting the three goals of the CRS: (1) reduce flood losses, (2) facilitate accurate
insurance rating, and (3) promote awareness of flood insurance. Municipalities could
expect significant cost savings on premiums if enrolled in the CRS program. CRS
premium discounts on flood insurance range from 5 percent for Class 9 communities
up to 45 percent for Class 1 communities.
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National Incident
Management System
(NIMS)
NIMS is a systematic approach for government, nongovernmental organizations, and
the private sector to work together to manage incidents involving hazards. The NIMS
provides a flexible but standardized set of incident management practices. Incidents
typically begin and end locally, and they are managed at the lowest possible
geographical, organizational, and jurisdictional level. In some cases, success depends
on the involvement of multiple jurisdictions, levels of government, functional agencies,
and emergency responder disciplines. These cases necessitate coordination across a
spectrum of organizations. Communities using NIMS follow a comprehensive national
approach that improves the effectiveness of emergency management and response
personnel across the full spectrum of potential hazards (including natural hazards,
technological hazards, and human-caused hazards) regardless of size or complexity.
Although participation is voluntary, federal departments and agencies are required to
make adoption of NIMS by local and state jurisdictions a condition to receive federal
preparedness grants and awards. The content of this plan is considered to be a viable
support tool for any phase of emergency management. The NIMS program is
considered a response function, and information in this floodplain management plan
can support the implementation and update of all NIMS-compliant plans within the
planning area.
Presidential Executive
Order 11988,
Floodplain
Management
Executive Order 11988 requires federal agencies to avoid to the extent possible the
long and short-term adverse impacts associated with the occupancy and modification
of floodplains and to avoid direct and indirect support of floodplain development
wherever there is a practicable alternative. It requires federal agencies to provide
leadership and take action to reduce the risk of flood loss, minimize the impact of
floods on human safety, health, and welfare, and restore and preserve the natural and
beneficial values of floodplains. The requirements apply to the following activities:
•
Acquiring, managing, and disposing of federal lands and facilities
•
Providing
federally
undertaken,
financed,
or
assisted
construction
and
improvements
•
Conducting federal activities and programs affecting land use, including but not
limited to water and related land resources planning, regulation, and licensing
Presidential Executive
Order 11990,
Protection of Wetlands
Executive Order 11990 requires federal agencies to provide leadership and take action
to minimize the destruction, loss, or degradation of wetlands, and to preserve and
enhance the natural and beneficial values of wetlands. The requirements apply to the
following activities:
•
Acquiring, managing, and disposing of federal lands and facilities
•
Conducting federal activities and programs affecting land use, including but not
limited to water and related land resources planning, regulation, and licensing.
All actions identified in this plan will seek full compliance with all applicable presidential
executive orders.
National Flood Insurance Program
The National Flood Insurance Program (NFIP) makes federally backed flood insurance available to
homeowners, renters, and business owners in participating communities that enact floodplain regulations.
For most participating communities, FEMA has prepared a detailed Flood Insurance Study. The study
presents water surface elevations for floods of various magnitudes, including the 1-percent-annual-chance
flood (called the 100-year flood or base flood) and the 0.2-percent-annual-chance flood (the 500-year
flood).
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Base flood elevations and the boundaries of the 100- and 500-year floodplains are shown on Flood
Insurance Rate Maps (FIRMs), which are the principle tools for identifying the extent and location of the
flood hazard. FIRMs are the most detailed and consistent data source available, and for many communities
they represent the minimum area of oversight under their floodplain management program.
Participants in the NFIP must, at a minimum, regulate development in floodplain areas in accordance with
NFIP criteria. Before issuing a permit to build in a floodplain, participating jurisdictions must ensure that
three criteria are met:
•
New buildings and those undergoing substantial improvements must, at a minimum, be elevated
to protect against damage by the 100-year flood.
•
New floodplain development must not aggravate existing flood problems or increase damage to
other properties.
•
New floodplain development must exercise a reasonable and prudent effort to reduce its adverse
impacts on threatened and endangered species.
Properties constructed after a FIRM has been adopted are eligible for reduced flood insurance rates. Such
structures are less vulnerable to flooding since they were constructed after regulations and codes were
adopted to decrease vulnerability. Properties built before a FIRM is adopted are more vulnerable to flooding
because they do not meet code or are located in hazardous areas.
CITY OF PHOENIX PARTICIPATION IN NFIP
The City of Phoenix participates in the NFIP and has adopted regulations that meet the NFIP requirements.
The City entered the NFIP when its first FIRM was issued on December 4, 1979. The effective date for the
current FIRM is February 8, 2024. Phoenix is currently in good standing with the provisions of the NFIP. A
detailed flood insurance study for the areas subject to flooding was originally completed on September 29,
1989, with updates in 1989, 1991, 1993, 1995, 2001, 2005, 2013, 2015, 2020, 2021, and the most recent
update on February 8, 2024 (FEMA 2024a). The capability assessment at the end of this chapter includes
a summary of the NFIP capabilities of the City of Phoenix.
As of March 3, 2025, 3,352 flood insurance policies in the City of Phoenix provide $887 million in coverage
at a combined annual premium of $2.5 million. According to FEMA statistics, 1,283 flood insurance claims
have been paid, for a total of $8.9 million.
NFIP REFORM
The Biggert-Waters Flood Insurance Reform Act of 2012 changed the NFIP to make it more sustainable. It
required the NFIP to raise rates to reflect true flood risk, make the program more financially stable, and
change how FIRM updates impact policyholders. The law eliminated some artificially low rates and
discounts, as well as subsidies to certain pre-FIRM policyholders. The law called for adjusting most flood
insurance rates to reflect full risk. It identified investments that property owners and communities can
make to reduce the impact of rate changes.
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The Homeowner Flood Insurance Affordability Act of 2014 delayed the increases in flood insurance
premiums mandated under the Biggert–Waters Flood Insurance Reform Act of 2012 for four years. During
that time, FEMA was to come up with a plan to make the premiums cheaper and reassess its maps of
areas that are likely to flood and therefore require flood insurance. The 2014 law also allowed those who
sell their homes to pass lower flood insurance premiums on to the next homeowner.
In April 2023, FEMA implemented Risk Rating 2.0: Equity in Action to consider specific characteristics of a
building to provide a more modern, individualized, and equitable flood insurance rates. The new rating
methodology considers frequency of flooding, multiple flood types, proximity to flood sources, and building
characteristics such as first floor heights and costs to rebuilt. It is difficult to determine what the aggregate
cost increase through Risk Rating 2.0 will be on post-mitigation properties.
These laws will have profound impacts on the costs of flood insurance and implementation of the NFIP.
How changes will impact local communities is not yet known.
State Planning and Regulatory Capabilities
Table 3-2 summarizes the planning and regulatory capabilities available to the City of Phoenix at the state
level.
Table 3-2. Summary of State Planning and Regulatory Capabilities
Capability
Details
Arizona Department of
Water Resources
The Arizona Revised Statutes (A.R.S.) § 45-1201 assigns the responsibility for
supervision of the safety of non-federal dams in the State of Arizona to the Director
of the Arizona Department of Water Resources (ADWR). The ADWR Engineering
Division is responsible for implementing the Flood Hazard Management Programs,
which include dam safety, flood warning, and floodplain management. An agency-
critical mission of the Engineering Division is to protect the public against potential
loss of life and property damage due to dam failure.
Arizona Revised Statute
(ARS) 26-308
State law under ARS 26-308 establishes that each county and incorporated city and
town is charged with establishing and providing emergency management within
their jurisdictions in accordance with state emergency plans and programs. State
emergency plans shall be in effect within all subdivisions and jurisdictions within the
state, and the governing bodies of each subdivision and jurisdiction may develop
additional emergency plans in support of state emergency plans. This includes all
response and recovery efforts outlined in the State Emergency Response and
Recovery Plan (SERRP)
Arizona Revised Statute
(ARS) 28-910
State law under ARS 28-910 charges that a driver who drives a vehicle on a public
street or highway that is barricaded due to being temporarily covered by rise in
water level from groundwater or overflow, is liable for the expenses of any
emergency response that is required to remove any driver or any passenger in the
vehicle should the vehicle become inoperable. This statute should serve as a
deterrent to prevent vehicle operators from driving through flooded areas.
ADWR Substantive Policy
Statements
ADWR Substantive Policy Statements are advisory only, and do not impose
additional requirements or penalties on regulated parties. This includes the policy
on the Development of Flood Control Plans, which was created to provide
assistance to county flood control districts in investigating flooding problems and
developing plans to control such problems. Another substantive policy is the Flood
Control Loan Program, which was established to enable county flood control
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districts to proceed with timely implementation of flood control projects authorized
for funding under the Alternative Flood Control Assistance Program.
County and Regional Planning and Regulatory Capabilities
Table 3-3 summarizes the planning and regulatory capabilities available to the City of Phoenix at the county
and regional levels.
Table 3-3 Summary of County and Regional Planning and Regulatory Capabilities
Capability
Details
Maricopa County Multi-
jurisdictional Hazard
Mitigation Plan (MJHMP)
The MJHMP reduces the risk to people and property and reduces the cost of
recovering from a disaster. A hazard mitigation plan can help communities
become more sustainable and disaster-resistant by focusing efforts on the
hazards, disaster-prone areas and identifying appropriate mitigation actions.
Effective mitigation planning and efforts can break the cycle of disaster damage,
reconstruction, and repeated damage. The MJHMP is reviewed and revised every 5
years and is available to the general public (MCDEM n.d.).
Maricopa County
Emergency Operations
Plan
Maricopa County has established a multi-hazard, functional plan that treats
emergency management activities generally with the unique aspects of individual
disasters contained in hazard specific annexes. It describes the emergency
organization and the means of coordination with other entities. It assigns
functional responsibilities and details tasks to be carried out as accurately as
permitted by the situation. The Maricopa County EOP is reviewed and revised
annually. It is for official use only and is not distributed to the general public
(MCDEM n.d.).
Maricopa County
Department of Emergency
Management Strategic
Plan 2024-2026
The Maricopa County Department of Emergency Management Strategic Plan
2024-2026 was developed to meet the vision of comprehensive county-wide
emergency management efforts through a multi-year strategy in coordination with
key emergency management stakeholders. This plan includes overarching
missions, strategic goals, objectives, milestones, and overall methods of
implementation.
The Maricopa County Department of Emergency Management Strategic Plan
2024-2026 provides a framework for supporting the community before, during, and
after disasters and improving the department's execution of its fundamental
mission to ensure a safe and resilient community for all residents. Maricopa
County Department of Emergency Management (MCDEM) is committed to
developing a coordinated and cooperative program that engages the "whole
community" in all efforts possible to prevent, protect, mitigate, respond to, and
recover from all hazards (MCDEM n.d.).
3.1.2
Administrative and Technical Capabilities
Administrative and technical capabilities focus on the availability of personnel resources responsible for
implementing all the facets of hazard mitigation. These resources include technical experts, such as
engineers and scientists, as well as personnel with capabilities that may be found in multiple departments,
such as grant writers.
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Federal Administrative and Technical Capabilities
Numerous federal agencies have specific administrative and technical capabilities that can support
floodplain management in the City of Phoenix.
Table 3-4 Summary of Federal Administrative and Technical Capabilities
Capability
Details
Federal Emergency
Management Agency
FEMA is responsible for providing assistance before, during, and after disasters.
FEMA is the federal reviewer of hazard mitigation plans, sets federal standards for
local and state hazard mitigation plans, and funds hazard mitigation plans.
Federal Energy Regulatory
Commission Dam Safety
Program
The Federal Energy Regulatory Commission (FERC) cooperates with a large
number of federal and state agencies to ensure and promote dam safety. The
Commission regulates over 1,700 non-federal dams in the U.S. Over 1,500
regulated hydroelectric projects are in the FERC program (FERC, 2020). Two-thirds
of these are more than 50 years old. As dams age, concern about their safety and
integrity grows, so oversight and regular inspection are important. FERC inspects
hydroelectric projects on an unscheduled basis to investigate the following:
•
Potential dam safety problems
•
Complaints about constructing and operating a project
•
Safety concerns related to natural disasters
•
Issues concerning compliance with the terms and conditions of a license.
Every five years, an independent engineer approved by the FERC must inspect and
evaluate projects with dams higher than 32.8 feet (10 meters), or with a total
storage capacity of more than 2,000 acre-feet.
FERC monitors seismic research and applies it in performing structural analyses of
hydroelectric projects. FERC also evaluates the effects of potential and actual
large floods on the safety of dams. During and following floods, FERC visits dams
and licensed projects, determines the extent of damage, if any, and directs any
necessary studies or remedial measures the licensee must undertake. The FERC
publication Engineering Guidelines for the Evaluation of Hydropower Projects
guides the FERC engineering staff and licensees in evaluating dam safety. The
publication is frequently revised to reflect current information and methodologies.
FERC requires licensees to prepare emergency action plans and conduct training
sessions on how to develop and test these plans. The plans outline an early
warning system if there is an actual or potential sudden release of water from a
dam due to failure. The plans include operational procedures that may be used,
such as reducing reservoir levels and reducing downstream flows, as well as
procedures for notifying affected residents and agencies responsible for
emergency management. These plans are frequently updated and tested to ensure
that everyone knows what to do in emergency situations.
Currently no dams are under FERC jurisdiction in the City of Phoenix.
National Dam Safety
Program (NDSP)
The NDSP is a partnership of state and federal agencies, and other stakeholders
that encourages individual and community responsibility for dam safety to protect
people from dam failures. It is administered through the Department of Homeland
Security and FEMA. The program improves safety and security around dams by
providing assistance grants to state dam safety agencies to assist them in
improving their regulatory programs; producing educational materials for dam
owners; funding research to enhance technical expertise as dams are built and
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rehabilitated; establishing training programs for dam safety inspectors; and
creating a National Inventory of Dams (NID) (FEMA 2024).
National Weather Service
(NWS)
The NWS monitors weather and delivers weather forecasting. Resources are
deployed as early as possible to prepare for storm impacts. The NWS also offers
various education and training programs on weather-related hazards (NWS n.d.)
•
StormReady®: The NWS operates the StormReady program, which
encourages communities to take a new, proactive approach to improving
local hazardous weather operations by providing emergency managers
with clear-cut guidelines on how to improve their hazardous weather
operations. To be recognized by the program, a community must establish
a 24-hour warning point and emergency operations center; have more than
one way to receive severe weather warnings and forecasts and to alert the
public; create a system that monitors weather conditions locally; promote
the importance of public readiness through community seminars; and
develop a formal hazardous weather plan, which includes training severe
weather spotters and holding emergency exercises (NWS n.d.). The City of
Phoenix is a recognized StormReady community.
U.S. Geological Survey
(USGS)
USGS maintains a network of gauges across Arizona that continuously measure
lake, reservoir, stream, and tidal levels. These data sets are transmitted to the
USGS and made available over the Internet. As project needs and funding levels
change, gauges may be added or deactivated, and deactivated gauges may be
reactivated (USGS n.d.).
United States Army Corps
of Engineers (USACE)
The USACE works to strengthen the nation’s security by building and maintaining
America’s infrastructure and providing military facilities where servicemembers
train, work, and live. Projects include dredging, storm damage reduction, and
ecosystem restoration in and near waterways (USACE n.d.). The City of Phoenix is
serviced by the Los Angeles district and the Arizona-Nevada Area Office. USACE
has numerous initiatives to support hazard mitigation measures, which are
described below.
•
Silver Jackets: Silver Jackets, developed by USACE, is the State-level
implementation program for the National Flood Risk Management
Program. The program’s goals are to leverage information and resources
from federal, state, and local agencies to improve flood risk management;
improve public risk communication through a united effort; and create a
mechanism to collaboratively solve issues and implement initiatives
beneficial to local communities. In Arizona, the Silver Jackets program is
led by the Arizona Department of Water Resources and Division of
Emergency Management with the support of the USACE (USACE n.d.).
•
Climate Preparedness and Resilience Community of Practice: The Practice
develops and implements practical, nationally consistent, and cost-
effective approaches and policies to reduce potential vulnerabilities to the
nation’s water infrastructure resulting from climate change and variability
(USACE n.d.).
•
Planning Assistance to States (PAS) Program: Section 22 of the 1974 Water
Resources Development Act provides authority for the USACE to assist
states, local governments, Native American Tribes, and other non-federal
entities in the preparation of comprehensive plans for the development
and conservation of water and related land resources. Types of work that
can be done include Water Quality Studies, Wetland Evaluation Studies,
Flood Plain Management Studies, Coastal Zone Management/Protection
Studies, Harbor/Port Studies, or other water resource planning
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investigations. The individual nonfederal sponsors determine the needed
planning assistance (USACE n.d.).
•
Flood Plain Management Services Program (FPMS): Section 206 of the
1960 Flood Control Act (PL 86-645), as amended, provides the authority
for the USACE to provide assistance and guidance on all aspects of
floodplain management planning. The program develops or interprets site-
specific data on obstructions to flood flows, flood formation, and timing,
and the extent, duration, and frequency of flooding. Upon request, program
services are provided to the State, regional, and local governments, Native
American Tribes, and other non-federal public agencies without charge
(USACE n.d.).
•
Inspection of Completed Works (ICW) Program: Civil works structures
whose failure or partial failure could jeopardize the operational integrity of
the project, endanger the lives and safety of the public, or cause
substantial property damage are periodically inspected and evaluated to
ensure their structural stability, safety, and operational adequacy. For
those structures constructed by the USACE and turned over to others for
operation and maintenance, the operating entity is responsible for periodic
inspection and evaluation. The USACE may conduct the inspection on
behalf of the project sponsor, provided appropriate reimbursement to the
USACE is made. However, the USACE may participate in the inspection
with the operating entity at the government’s expense (USACE n.d.).
•
Rehabilitation and Inspection Program (RIP): RIP is a USACE program that
provides for inspection of flood control projects, the rehabilitation of
damaged flood control projects, and the rehabilitation of federally
authorized and constructed hurricane or shore protection projects (USACE
n.d.).
•
Dam Safety Program: The U.S. Army Corps of Engineers operates and
maintains approximately 700 dams nationwide. It is also responsible for
safety inspections of some federal and non-federal dams in the United
States that meet the size and storage limitations specified in the National
Dam Safety Act. The Corps has inventoried dams; surveyed each state and
federal agency’s capabilities, practices and regulations regarding design,
construction, operation and maintenance of the dams; and developed
guidelines for inspection and evaluation of dam safety. The Corps
maintains the National Inventory of Dams, which contains information
about a dam’s location, size, purpose, type, last inspection and regulatory
status (USACE 2020).
National Incident
Management System
Adoption of this system for government, nongovernmental organizations, and the
private sector to work together to manage incidents involving hazards is a
prerequisite for federal preparedness grants and awards.
State Administrative and Technical Capabilities
Numerous state agencies have specific administrative and technical capabilities that can support
floodplain management in the City of Phoenix.
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Table 3-5 Summary of State Administrative and Technical Capabilities
Capability
Details
Arizona Department of
Water Resources (ADWR)
ADWR’s floodplain management program is partially funded by FEMA’s
Community Assistance Program (CAP). One of the main objectives of the CAP is to
ensure that jurisdictions adopt and enforce floodplain management regulations in
accordance with the requirements of the NFIP and the Arizona Revised Statutes
(ARS). Through this program, Community Assistance Visits (CAVs) are made to the
state’s NFIP participating communities. It is the goal of ADWR to visit communities
periodically to provide updates on state and federal floodplain management
program changes, provide technical and programmatic assistance, and verify that
development in flood prone areas is compliant with local floodplain management
regulations (Arizona Department of Emergency and Military Affairs 2023).
Arizona Department of
Emergency and Military
Affairs
The Response Branch is the coordination point for the state’s response and
support efforts to the impacted counties and tribes through the allocation of state
resources. When a disaster exceeds local capacities and capabilities, the impacted
jurisdiction may ask county emergency management for assistance. If the
response needs of the impacted jurisdiction exceed the capabilities of the county,
they may request assistance from other counties and/or the State of Arizona.
The Arizona State Emergency Operation Center (SEOC) is the support and
coordination facility for state assistance and the Response Branch manages the
SEOC when activated. DEMA may recall representatives of state and non-
governmental organizations to staff its various Emergency Support Functions
within the SEOC and to provide coordinated support to local emergency
management response and recovery activities (AZ DEMA n.d.).
The Logistics Branch provides high-quality logistical and communications support
during the day-to-day operations of DEMA. During declared emergencies, logistics
coordinates the allocation of equipment, services, and personnel to support
emergency operations (AZ DEMA n.d.).
The Recovery Branch is responsible for providing leadership when assisting
communities, individuals, families, and businesses responding to and recovering
from disaster damages. The Recovery Human Services mission is to reduce
human suffering during disasters and enhance recovery after disasters. The
Recovery Branch oversees the administration of the Individual Assistance
Program; Mass Care (ESF-6); and Disability, Access & Functional Needs; Voluntary
Agency and the Private Sector Liaison. The Recovery and Infrastructure Branch
collaborate to conduct the "Recovery Road Show" briefing for local jurisdictions on
the various Recovery programs, as well as providing "best practices" for the
programs (AZ DEMA n.d.).
The Exercise Branch focuses on preparedness, partnerships, and leadership. The
focus of an exercise should always be on locating and eliminating problems before
an actual emergency occurs. Corrective actions are an important part of exercise
design, evaluation, and after-action reports. In planning exercises, the emphasis is
on the actions or operations required in emergency response or recovery rather
than on the types of disasters, because preparedness is common to all
emergencies (AZ DEMA n.d.).
The Planning Branch is responsible for developing and maintaining emergency
plans and procedures, as well as coordinating the development of plans across
different agencies and organizations. The Planning Branch also conducts risk
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assessments and identifies potential hazards and vulnerabilities, as well as
providing recommendations for mitigation measures. During an emergency, the
Planning Branch is responsible for maintaining situational awareness and
providing strategic guidance to ensure the effective and efficient use of resources.
This includes tracking the progress of response operations, identifying emerging
issues and concerns, and providing support to the Incident Commander and other
operational personnel. Overall, the Planning Branch plays a critical role in
emergency management by providing the necessary guidance and resources to
ensure an effective response to emergencies and disasters (AZ DEMA n.d.).
The DEMA Situation Unit supports agency initiatives and projects through all
phases of emergency management, from developing web applications,
administrating workflows, conducting critical data stewardship, and maintaining
day-to-day operations of crisis information management systems, Geographical
Information Systems (GIS), and business intelligence. During an emergency
incident, the Situation Unit collects, processes, and organizes information, prepares
situation summaries, and develop projections and forecasts related to the incident
(AZ DEMA n.d.).
The Training Branch provides a variety of courses throughout Arizona, as well as
arranging for attendance at training for many out-of-state federal programs (AZ
DEMA n.d.).
County and Regional Administrative and Technical Capabilities
Numerous county and regional agencies have specific administrative and technical capabilities that can
support floodplain management in the City of Phoenix.
Table 3-6 Summary of County and Regional Administrative and Technical Capabilities
Capability
Details
Maricopa County Flood
Control District
The Maricopa County Flood Control District mission is to reduce risk from flooding
so that property damage and loss of life is minimized, economic development is
supported in a safe and responsible manner and storm water is recognized as a
resource for the long-term benefit of the community and environment. The District
is a community partner working with citizens and stakeholders to reduce risk from
flooding. This is accomplished through exceptional customer service, technical
expertise, fiscally responsible actions and multi-use projects (Maricopa County
n.d.).
Maricopa County
Emergency Management
Emergency Management provides on-going planning to prevent and prepare for
large-scale emergencies in Maricopa County. Emergency Management protects
communities by coordinating and integrating all activities necessary to build,
sustain, and improve the capability to mitigate against, prepare for, respond to, and
recover from threatened or actual natural disasters, acts of terrorism, or other
man-made disasters (MCDEM n.d.).
Maricopa County
Community Organizations
Active in Disaster
(MCCOAD)
The MCCOAD was established in January 2020 to increase the ability of
community organizations to effectively and efficiently respond to disasters. During
a disaster, the Maricopa County Department of Emergency Management (MCDEM)
can activate the MCCOAD to assist in response and recovery. The MCCOAD
provides an essential service to our community by streamlining request fulfillment
and communication. The MCCOAD serves as a liaison between government
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agencies and community organizations within the existing county emergency
management structure (MCDEM n.d.).
Maricopa County Local
Emergency Planning
Committee (MC-LEPC)
The MC-LEPC is a committee composed of community volunteers from elected
positions, the emergency services field, media agencies, community groups, and
industry; appointed by the Arizona State Emergency Response Commission
(“AzSERC”), which also maintains oversight authority over the committee. The MC-
LEPC is tasked as a community body to oversee local compliance with the
Emergency Planning and Community Right to Know Act (“EPCRA”), 42 U.S.C. §
11001 – 11050. EPCRA requires all facilities that have hazardous substances at or
in excess of certain amounts to provide the Arizona Department of Environmental
Quality (“ADEQ”) with the identity of the facility representative who must provide
that facility’s emergency plan and who will also participate in the emergency
planning process. Among the duties of these facilities is the duty to submit a list
and inventory of its hazardous substances that are present at or above certain
threshold quantities and prepare and file with ADEQ and the MC-LEPC an
emergency response plan as required in statute (MCDEM n.d.).
3.1.3
Fiscal Capabilities
Fiscal capabilities are the resources that a jurisdiction has access to or is eligible to use to fund mitigation
actions.
Federal Fiscal Capabilities
Table 3-7 describes the federal fiscal capabilities available to support floodplain mitigation in the City of
Phoenix.
Table 3-7 Summary of Federal Fiscal Capabilities
Capability
Details
Hazard Mitigation Grant
Program (HMGP)
Responsible Agency:
FEMA
The HMGP provides funding to states, local communities, tribes, and territory
governments so they can rebuild in a way that reduces or mitigates future natural
disaster losses in their communities. HMGP funding is authorized with a
Presidential Major Disaster Declaration. A governor or tribal chief executive may
request HMGP funding throughout the state, tribe, or territory when submitting a
disaster declaration. Through HMGP, states can access up to 10 percent and local
governments up to 5 percent of their HMGP award for management and
administration costs (FEMA 2024a).
Flood Mitigation
Assistance (FMA)
Responsible Agency:
FEMA
FMA grants provide funding to states, local communities, tribes, and territories to
reduce or eliminate the risk of repetitive flood damage to buildings insured under
the NFIP. FEMA distributes funds annually to develop community or individual flood
mitigation projects. In addition, funding is also used for technical assistance and
management costs. All sub-applicants need to be in good standing with the NFIP
(FEMA 2024a).
Public Assistance (PA)
Section 406 Funds
Responsible Agency:
FEMA
FEMA funds cost-effective mitigation measures under the PA program for repairs,
restoration, and replacement of eligible damaged facilities. This grant funding is
commonly referred as "406 Mitigation" or PA Mitigation (FEMA 2024b).
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Legislative Pre-Disaster
Mitigation (LPDM)
Responsible Agency:
FEMA
The Pre-Disaster Mitigation Program (PDM) was active during the performance of
the 2019 SHMP but was replaced with BRIC under the Disaster Recovery Reform
Act of 2018. However, LPDM awards are still funded through direct congressional
appropriations (FEMA 2024b).
Safeguarding Tomorrow
through Ongoing Risk
Mitigation Revolving Loan
Fund (STORM RLF)
Responsible Agency:
FEMA
The STORM RLF program complements and supplements FEMA’s Hazard
Mitigation Assistance grant portfolio to support mitigation projects at the local
government level and increase the nation’s resilience to natural hazards and climate
change. These low interest loans will allow jurisdictions to reduce vulnerability to
natural disasters, foster greater community resilience and reduce disaster suffering
(FEMA 2024b).
Extraordinary
Circumstances
Responsible Agency:
FEMA
For PDM and FMA project subawards, the (FEMA) Region may apply extraordinary
circumstances when justification is provided and with concurrence from FEMA
Headquarters (Risk Reduction and Risk Analysis Divisions) prior to granting an
exception. If this exception is granted, a local mitigation plan must be approved by
FEMA within 12 months of the award of the project subaward to that community.
For HMGP, PDM, and FMA, extraordinary circumstances exist when a determination
is made by the Applicant and FEMA that the proposed project is consistent with the
priorities and strategies identified in the State (Standard or Enhanced) Mitigation
Plan and that the jurisdiction meets at least one of the criteria below. If the
jurisdiction does not meet at least one of these criteria, the Region must coordinate
with FEMA Headquarters (Risk Reduction and Risk Analysis Divisions) for HMGP;
however, for PDM and FMA the Region must coordinate and seek concurrence prior
to granting an exception:
•
The jurisdiction meets the small, impoverished community criteria (see Part
VIII, B.2).
•
The jurisdiction has been determined to have had insufficient capacity due
to lack of available funding, staffing, or other necessary expertise to satisfy
the mitigation planning requirement prior to the current disaster or
application deadline.
•
The jurisdiction has been determined to have been at low risk from hazards
because of low frequency of occurrence or minimal damage from previous
occurrences as a result of sparse development.
•
The jurisdiction experienced significant disruption from a declared disaster
or another event that impacts its ability to complete the mitigation planning
process prior to award or final approval of a project award.
•
The jurisdiction does not have a mitigation plan for reasons beyond the
control of the State, federally recognized tribe, or local community, such as
Disaster Relief Fund restrictions that delay FEMA from granting a subaward
prior to the expiration of the local or Tribal Mitigation Plan.
For HMGP, PDM, and FMA, the Applicant must provide written justification that
identifies the specific criteria or circumstance listed above, explains why there is no
longer an impediment to satisfying the mitigation planning requirement, and
identifies the specific actions or circumstances that eliminated the deficiency.
When an HMGP project funding is awarded under extraordinary circumstances, the
Recipient shall acknowledge in writing to the Regional Administrator that a plan will
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be completed within 12 months of the subaward. The Recipient must provide a
work plan for completing the local or Tribal Mitigation Plan, including milestones
and a timetable, to ensure that the jurisdiction will complete the plan in the required
time. This requirement shall be incorporated into the award (both the planning and
project subaward agreements, if a planning subaward is also awarded).
Individual Assistance
Responsible Agency:
FEMA
Individual Assistance (IA) provides help for homeowners, renters, businesses, and
some non-profit entities after disasters occur. This program is largely funded by the
U.S. Small Business Administration. For homeowners and renters, those who
suffered uninsured or underinsured losses could be eligible for a Home Disaster
Loan to repair or replace damaged real estate or personal property. Renters are
eligible for loans to cover personal property losses. Individuals are allowed to
borrow up to $200,000 to repair or replace real estate, $40,000 to cover losses to
personal property, and an additional 20 percent for mitigation. For businesses, loans
could be made to repair or replace disaster damages to property owned by the
business, including real estate, machinery and equipment, inventory, and supplies.
Businesses of any size are eligible. Non-profit organizations, such as charities,
churches, and private universities are eligible. An Economic Injury Disaster Loan
provides necessary working capital until normal operations resume after a physical
disaster but are restricted by law to small businesses only. IA is detailed on the
FEMA website: https://www.fema.gov/individual-disaster-assistance
Department of Homeland
Security Grant Program
Responsible Agency:
FEMA
The Homeland Security Grant Program (HSGP) plays an important role in the
implementation of the National Preparedness System by supporting the building,
sustainment, and delivery of core capabilities essential to achieving the National
Preparedness Goal of a secure and resilient nation. In FY 2019, the total amount of
funds available under HSGP was $1.095 billion.
Additional information regarding HSGP is available on the website:
https://www.fema.gov/homeland-security-grant-program.
High Hazard Potential
Dams Grant Program
Responsible Agency:
FEMA
The Rehabilitation of High Hazard Potential Dams Grant Program provides
technical, planning, design, and construction assistance in the form of grants to
non-Federal governmental organizations or nonprofit organizations for
rehabilitation of eligible high-hazard potential dams. Information regarding this
program is available on the website: https://www.grants.gov/web/grants/view-
opportunity.html?oppId=316238
National Dam Safety
Program (NDSP)
Responsible Agency:
FEMA
The NDSP, which is led by FEMA, is a partnership of the states, federal agencies,
and other stakeholders to encourage individual and community responsibility for
dam safety. Grant assistance is provided to states, providing vital support for the
improvement of state dam safety programs that regulate most of the dams in the
United States. Additional information regarding the NDSP is available on the
website: https://www.fema.gov/emergency-managers/risk-management/dam-
safety
Infrastructure Investment
and Jobs Act (IIJA)
Responsible Agency:
FEMA
The IIJA, most commonly known as the Bipartisan Infrastructure Bill and originally
in the House as the Investing in New Vision for the Environment and Surface
Transportation (INVEST) in America Act (H.R. 3684) was signed into law by
President Biden in November 2021. Various funds are expected to be made
available through this Act to support hazard mitigation, including funding and
programs related to carbon reduction. The bill provides around $7 billion to FEMA
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for assisting communities in preparing for and adapting to climate related disasters.
The bill also funds the Bridge Investment Program to provide grant funding to
replace, rehabilitate, preserve, or make resiliency improvements to bridges.
Small Business
Administration Loan
Responsible Agency:
SBA
The Small Business Administration (SBA) provides low-interest disaster loans to
homeowners, renters, businesses of all sizes, and most private nonprofit
organizations. SBA disaster loans can be used to repair or replace the following
items damaged or destroyed in a declared disaster: real estate, personal property,
machinery and equipment, and inventory and business assets.
Homeowners could apply for up to $200,000 to replace or repair their primary
residence. Renters and homeowners could borrow up to $40,000 to replace or
repair personal property such as clothing, furniture, cars, and appliances that were
damaged or destroyed in a disaster. Physical disaster loans of up to $2 million are
available to qualified businesses or most private nonprofit organizations.
Additional information regarding SBA loans is available on the SBA website:
https://www.sba.gov/managing-business/running-business/emergency-
preparedness/disaster-assistance.
Community Development
Block Grant Program
Responsible Agency:
HUD
CDBG are federal funds intended to provide low and moderate-income households
with viable communities, including decent housing, a suitable living environment,
and expanded economic opportunities. Eligible activities include community
facilities and improvements, roads and infrastructure, housing rehabilitation and
preservation, development activities, public services, economic development, and
planning and administration. Public improvements could include flood and drainage
improvements. In limited instances and during the times of “urgent need” (e.g., post-
disaster) as defined by the CDBG National Objectives, CDBG funding could be used
to acquire a property located in a floodplain that was severely damaged by a recent
flood, demolish a structure severely damaged by an earthquake, or repair a public
facility severely damaged by a hazard event. Funding is split into two programs:
Community Development Block Grant Disaster Recovery (CDBG-DR) Program: This
program provides grant funds, which are appropriated by Congress and allocated
by HUD to rebuild disaster-impacted areas and provide crucial seed money to start
the long-term recovery process. These flexible grants help cities, counties, Indian
tribes, and States recover from Presidentially declared disasters, especially in low-
income areas, subject to availability of supplemental appropriations. Since CDBG-
DR assistance may fund a broad range of recovery activities, HUD can help
communities and neighborhoods that otherwise might not recover due to limited
resources.
Community Development Block Grant Mitigation (CDBG-MIT): This program funds
pose a unique opportunity for eligible grantees to use this assistance in areas
impacted by recent disasters to carry out strategic and high-impact activities to
mitigate disaster risks and reduce future losses. CDBG-MIT defines mitigation as
activities that increase resilience to disasters and reduce or eliminate the long-term
risk of loss of life, injury, damage to and loss of property, and suffering and hardship
by lessening the impact of future disasters. Goals of CDBG-MIT funds:
•
Support data-informed investments, focusing on repetitive loss of property and
critical infrastructure.
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•
Build capacity to comprehensively analyze disaster risks and update hazard
mitigation plans.
•
Support the adoption of policies that reflect local and regional priorities that will
have long-lasting effects on community risk reduction, including risk reduction to
community lifelines and decreasing future disaster costs.
•
Maximize the impact of funds by encouraging leverage, private/public
partnerships, and coordination with other Federal dollars.
Additional information regarding CDBG is available on the website:
https://www.hudexchange.info/programs/cdbg-entitlement/
Federal Highway
Administration-
Emergency Relief
Responsible Agency:
U.S. DOT
The Federal Highway Administration (FHWA) Emergency Relief is a grant program
through the U.S. Department of Transportation (DOT) that can be used for repair or
reconstruction of federal-aid highways and roads on federal lands that have
suffered serious damage as a result of a disaster. Additional information regarding
the FHWA Emergency Relief Program is available on the website:
https://www.fhwa.dot.gov/programadmin/erelief.cfm
Federal Transit
Administration -
Emergency Relief
Responsible Agency:
U.S. DOT
The Federal Transit Authority (FTA) Emergency Relief is a grant program that funds
capital projects to protect, repair, reconstruct, or replace equipment and facilities of
public transportation systems. Additional information regarding the FTA Emergency
Relief Program is available on the website:
https://www.transit.dot.gov/funding/grant-programs/emergency-relief-
program/emergency-relief-program
Disaster Housing
Program
Responsible Agency:
HUD
Emergency assistance for housing, including minor repair of home to establish
livable conditions, mortgage, and rental assistance available through the U.S.
Department of Housing and Urban Development (HUD). Information on this
program is available on the website:
https://www.hud.gov/program_offices/public_indian_housing/publications/dhap
HOME Investment
Partnerships Program
Responsible Agency:
HUD
Grants to local and state government and consortia for permanent and transitional
housing (including financial support for property acquisition and rehabilitation for
low-income persons). Information on this program is available on the website:
https://www.hud.gov/program_offices/comm_planning/affordablehousing/progra
ms/home/
HUD Disaster Recover
Assistance
Responsible Agency:
HUD
Grants to fund gaps in available recovery assistance after disasters (including
mitigation). Information on this program is available on the website:
https://www.hud.gov/info/disasterresources
Section 108 Loan
Guarantee
Responsible Agency:
HUD
Enables states and local governments participating in the CDBG program to obtain
federally guaranteed loans for disaster-distressed areas. Information on this
program is available on the website:
https://www.hudexchange.info/programs/section-108/
Smart Growth
Implementation
Assistance program
Responsible Agency:
USEPA
The Smart Growth Implementation Assistance (SGIA) program through the U.S.
Environmental Protection Agency (USEPA) focuses on complex or cutting-edge
issues, such as stormwater management, code revision, transit-oriented
development, affordable housing, infill development, corridor planning, green
building, and climate change. Applicants can submit proposals under four
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categories: community resilience to disasters, job creation, the role of
manufactured homes in sustainable neighborhood design, or medical and social
service facilities siting. Information on this program is available on the website:
https://www.epa.gov/smartgrowth
Partners for Fish and
Wildlife
Responsible Agency:
U.S. Fish and Wildlife Service
Financial and technical assistance to private landowners interested in pursuing
habitat restoration projects, including those affecting wetlands and riparian
habitats. Information on this program is available on the website:
https://www.fws.gov/partners/
National Fish Passage
Program (NFPP)
Responsible Agency:
U.S. Fish and Wildlife Service
The National Fish Passage Program partners with local communities on a voluntary
basis to remove or bypass barriers, such as dams, to restore rivers and conserve
aquatic resources. The program provides both financial and technical assistance
for fish passage projects, which is any activity that improves the ability of fish or
other aquatic species to move by reconnecting habitat that has been fragmented by
a barrier. Information on this program is available on the website:
https://www.fws.gov/program/national-fish-passage
Rebuilding American
Infrastructure with
Sustainability and Equity
(RAISE)
Responsible Agency:
U.S. DOT
Investing in critical road, rail, transit, and port projects across the nation. The RAISE
program is previously known as Better Utilizing Investments to Leverage
Development (BUILD) and Transportation Investment Generating Economic
Recovery (TIGER). Information on this program is available on the website:
https://www.transportation.gov/tags/tiger-grants
Community Facilities
Direct Loan & Grant
Program
Responsible Agency:
USDA
This program provides affordable funding to develop essential community facilities
in rural areas. An essential community facility is defined as a facility that provides
an essential service to the local community for the orderly development of the
community in a primarily rural area and does not include private, commercial, or
business undertakings. Information on this program is available on the website:
https://www.rd.usda.gov/programs-services/community-facilities-direct-loan-grant-
program
Emergency Loan Program
Responsible Agency:
USDA
USDA’s Farm Service Agency provides emergency loans to help producers recover
from production and physical losses due to drought, flooding, other natural
disasters, or quarantine. Information on this program is available on the website:
https://www.fsa.usda.gov/programs-and-services/farm-loan-programs/emergency-
farm-loans/index
Emergency Watershed
Protection Program
Responsible Agency:
USDA
The Emergency Watershed Protection (EWP) program provides assistance to
relieve imminent hazards to life and property caused by floods, fires, drought,
windstorms, and other natural occurrences through the Natural Resources
Conservation Service. Information on this program is available on the website:
https://www.nrcs.usda.gov/wps/portal/nrcs/main/national/programs/landscape/e
wpp/
Financial Assistance
Responsible Agency:
NRCS
The Emergency Watershed Protection (EWP) program provides assistance to
relieve imminent hazards to life and property caused by floods, fires, drought,
windstorms, and other natural occurrences through the Natural Resources
Conservation Service. Information on this program is available on the website:
https://www.nrcs.usda.gov/wps/portal/nrcs/main/national/programs/landscape/e
wpp/
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Watershed Rehabilitation
Program
Responsible Agency:
NRCS
The Watershed Rehabilitation Program helps project sponsors rehabilitate aging
dams that are reaching the end of their design lives. This rehabilitation addresses
critical public health and safety concerns. NRCS selects projects based on the risks
to life and property if a dam failure were to occur. Information on this program is
available on the website: https://www.nrcs.usda.gov/programs-
initiatives/watershed-rehabilitation
Watershed and Flood
Prevention Operations
(WFPO) Program
Responsible Agency:
NRCS
The purpose of the program is to help units of federal, state, local, and federally
recognized tribal governments (project sponsors) protect and restore watersheds
The WFPO program provides technical and financial assistance to States, local
governments, and Tribal organizations to help plan and implement authorized
watershed projects for the purpose of:
•
Flood Prevention
•
Watershed Protection
•
Public Recreation
•
Public Fish and Wildlife
•
Agricultural Water Management
•
Municipal and Industrial Water Supply
•
Water Quality Management
Information on this program is available on the website:
https://www.nrcs.usda.gov/programs-initiatives/watershed-and-flood-prevention-
operations-wfpo-program
Emergency Management
Performance Grants
(EMPG) Program
Responsible Agency:
U.S. DHS
Emergency Management Performance Grant (EMPG) funding is available to
educate people and protect lives and structures from natural and technical hazards.
The grant is to encourage the development of comprehensive emergency
management, including terrorism consequence management, at the state and local
level and to improve emergency management planning, preparedness, mitigation,
response, and recovery capabilities. Information on this program is available on the
website: https://www.fema.gov/emergency-management-performance-grant-
program
Land & Water
Conservation Fund
Responsible Agency:
National Park Service
Matching grants to states and local governments for the acquisition and
development of public outdoor recreation areas and facilities (as well as funding for
shared federal land acquisition and conservation strategies). Information on this
program is available on the website: https://www.nps.gov/subjects/lwcf/index.htm
Clean Water Act Section
319(h) Grants
Responsible Agency:
USEPA
Clean Water Act Section 319(h) funds are provided only to designated state and
tribal agencies to implement their approved nonpoint source management
programs. State and tribal nonpoint source programs include a variety of
components, including technical assistance, financial assistance, education,
training, technology transfer, demonstration projects, and regulatory programs.
Each year, USEPA awards Section 319(h) funds to states in accordance with a
state-by-state allocation formula that EPA has developed in consultation with the
states (USEPA 2024a).
Section 319(h) funding decisions are made by the states. States submit their
proposed funding plans to USEPA. If a state’s funding plan is consistent with grant
eligibility requirements and procedures, USEPA then awards the funds to the state
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Capability
Details
(USEPA 2024a). Information on this program is available on the website:
https://www.epa.gov/nps/319-grant-program-states-and-territories
Community-Based
Restoration (CBRP)
Responsible Agency:
NOAA
The program grants support restoration projects that use a habitat-based approach
to rebuild productive and sustainable fisheries, contribute to the recovery and
conservation of protected resources, and promote healthy ecosystems and resilient
communities. Information on this program is available on the website:
https://www.fisheries.noaa.gov/national/habitat-conservation/community-based-
habitat-restoration
USACE Planning
Assistance to States
(PAS) Program
Responsible Agency:
USACE
Section 22 of the 1974 Water Resources Development Act provides authority for the
US Army Corps of Engineers Planning Assistance to the States (PAS) and Indian
Nations. Under this program, the USACE assists the States, local governments,
Native American Tribes, and other non-federal entities in the preparation of
comprehensive plans for the development and conservation of water and related
land resources. Types of work that can be done include Water Quality Studies,
Wetland Evaluation Studies, Flood Plain Management Studies, Coastal Zone
Management/Protection Studies, Harbor/Port Studies, or other water resource
planning investigations. The needed planning assistance is determined by the
individual non-federal sponsors.
USACE Continuing
Authorities Program
(CAP)
Responsible Agency:
USACE
Congress has provided USACE with a number of standing authorities to study and
build water resource projects for various purposes without additional project-
specific congressional authorization. The types of projects addressed by the CAP
include emergency streambank and shoreline erosion, flood control projects,
snagging and clearing for flood control, and small beach erosion control projects.
Cost-share varies based on subprograms.
USACE General
Investigation (GI)
Responsible Agency:
USACE
These are congressionally authorized studies under USACE’s Civil Works program.
Congress can authorize USACE to study, design, and construct major flood risk
management projects. The feasibility study is cost-shared 50/50 and construction
is cost-shared 65/35 between the federal government and non-federal sponsor.
These are generally large-scale projects that cost more than $10 million. Congress
can also authorize USACE to conduct other water-related studies/projects such as
watershed assessments, ecosystem restoration, and navigation improvements.
Section 206 Aquatic
Ecosystem Restoration
Projects
Responsible Agency:
USACE
The purpose of the USACE ecosystem restoration activities is to restore significant
ecosystem function, structure, and dynamic processes that have been degraded.
Ecosystem restoration efforts involve examining the problems contributing to the
system degradation and developing alternative means to solve these problems.
This program has previously been used to fund dam removal and provide for fish
passage. Cost shares vary by project type.
Planning Assistance to
the States
Responsible Agency:
USACE
The USACE is authorized to provide planning assistance, usually for a specific
technical item rather than detailed designs for construction. Dam safety/failure
studies have been conducted in recent years. To request assistance, state, local, or
tribal entities should submit a letter to the Chief of the Planning Division in their
USACE district detailing the location and nature of
the problem to be investigated. For more information and to review a sample
request letter, visit the USACE webpage.
Responsible Agency:
USACE
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Capability
Details
Small Flood Control
Program
Under the Small Flood Control Program, the USACE works with communities to
plan, design, and construct certain small flood control projects that have not already
been specifically authorized by Congress. Studies are required to evaluate potential
projects. Each project selected must be:
•
Economically justified, meaning the benefits of the project outweigh the cost of
construction
•
Environmentally acceptable
•
Complete within itself
State and Local Fiscal Capabilities
Table 3-8 describes the state fiscal capabilities available to support floodplain mitigation in the City of
Phoenix.
Table 3-8 Summary of State Fiscal Capabilities
Capability
Details
Governor’s Emergency
Fund (GEF)
Responsible Agency:
Governor’s Office
This fund receives four million dollars annually from the State’s General Fund to
assist government agencies respond to and recover from emergency and disaster
events. Unused funds at the end of the state’s fiscal year may be used as a funding
source for the implementation of mitigation projects. The Governor’s Emergency
Fund may be utilized for mitigation projects statewide (Arizona Department of
Emergency and Military Affairs 2023).
State Dam Repair Fund
Responsible Agency:
Arizona Department of Water Resources (ADWR)
In accordance with State statutes, ADWR has established, and maintains and
manages a Dam Repair Fund. Monies from this fund have been used to address
deficiencies at unsafe High Hazard Potential Dams (HHPDs) in the State. ADWR has
also used these funds as the non-Federal cost-share for HHPD grants. Through the
Dam Repair Fund, ADWR provided financial assistance to Navajo County to stabilize
the breach at Millet Swale Dam. ADWR continues to actively seek out opportunities
to assist local communities and dam owners mitigate risk posed by their HHPDs
(Arizona Department of Emergency and Military Affairs 2023).
The Arizona Department of Emergency and Military Affairs administers FEMA’s Hazard Mitigation
Assistance (HMA) grant program for the State of Arizona. The grant program is delivered to state agencies
and local jurisdictions (Arizona Department of Emergency and Military Affairs 2023).
County and Regional Fiscal Capabilities
The Maricopa County Flood District has several funding programs that can support floodplain
management (Maricopa County Flood District n.d.):
•
Capital Improvement Program: Capital improvement projects typically consist of the design and
construction of flood control infrastructure.
•
Small Project Assistance Program (SPAP): SPAP is directed and structured for the rapid design and
construction of smaller and localized flood control projects.
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•
Floodprone Property Assistance Program: The Floodprone Property Assistance Program provides
resources to mitigate flood hazards where the construction of flood control structures is
impractical. Homeowners living within delineated floodplains may apply for assistance under this
program. Eligible homeowners may qualify for a voluntary sale to the Maricopa County Flood
District at appraised market value and for assistance with moving expenses under certain
circumstances.
3.1.4
Local Capability Assessment
The City of Phoenix compiled an inventory and analysis of existing local authorities and capabilities. This
assessment identifies potential gaps in the jurisdiction’s capabilities. If the capability assessment
identified an opportunity to add a missing capability or expand an existing one, then doing so has been
selected as an action in the 2025 FMP’s action plan.
Legal and Regulatory Capabilities
The table below summarizes the planning documents that contribute to flood risk reduction in the City of
Phoenix.
Table 3-9. Planning Capabilities
Capability
in Place?
(Yes/No)
Name and Date
Department/Agency
Responsible
Master Plan
Yes
Phoenix General Plan 2025
Planning and Development
Impact on Risk Reduction:
Comprehensive planning is a state requirement and a foundation for various planning documents and
ordinances that provide for their respective jurisdiction's future growth and improvement. A comprehensive plan
is a document that guides the future actions of a community by presenting a vision for the future with long-term
goals and objectives for all activities that affect the local government. Comprehensive planning provides for
citizens' health, safety, and general welfare through orderly development and designated land use.
The Phoenix General Plan is the long-range guide for the city, and addresses issues such as energy, housing,
neighborhoods, public facilities, natural resources, transportation and land use. Arizona State Statutes require
that this plan be updated and/or readopted every ten years by a public vote.
Capital Improvement
Plan
Yes
Capital Improvement Program, 2023-
2028
City Council
Impact on Risk Reduction:
The Capital Improvement Program is a five-year plan for capital expenditures needed to replace, expand and
improve infrastructure and systems. Other planning processes, the most significant of which are explained in this
section, identify the need and provide funding for capital projects and related operating costs.
Stormwater
Management Plan
Yes
2023 Stormwater Management Plan
Phoenix Water Smart
Impact on Risk Reduction:
The City of Phoenix (City) Stormwater Management Plan (SWMP) is a detailed plan that identifies the major
programs, policies, and procedures implemented by the City to minimize the impact of urban activities on the
quality of stormwater. The City is required to develop this plan as a large Municipal Separate Storm Sewer
System (MS4) under the Arizona Pollutant Discharge Elimination System (AZPDES) permit program administered
by the Arizona Department of Environmental Quality (ADEQ).
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Capability
in Place?
(Yes/No)
Name and Date
Department/Agency
Responsible
The SWMP addresses the major programmatic areas including Public Education and Outreach, Public
Involvement, Illicit Discharge Detection and Elimination (IDDE), Municipal Facilities, Industrial Sites, Construction
Sites, Post-Construction, and the wet weather monitoring program. The SWMP is a comprehensive document
that has been written to reflect the requirements of the permit in addition to providing the details of the major
programmatic areas; therefore the SWMP includes an introduction and regulatory overview, a description of how
the stormwater program is managed, sections addressing the major programmatic areas, and additional
sections describing the training program, the monitoring program, and the approach to evaluating program
effectiveness.
This plan was developed with input from multiple City departments and approved by the applicable department
directors.
Watershed Plan
Yes
Metro Phoenix Area Drainage Master
Plan
Flood Control District of
Maricopa County,
City of Phoenix
Impact on Risk Reduction:
The Metro Phoenix Area Drainage Master Plan Update (Metro ADMPU) is underway to develop and recommend
strategies to reduce flood hazards and protect public safety in a study area located within the cities of Phoenix,
Scottsdale, and Tempe. The plan will update and refine the findings of the original Metro Phoenix Area Drainage
Master Plan completed in 2008. This update will use newer modeling techniques and updated mapping to
capture recent land use changes and better identify the extent of drainage and flooding problems within the
study area. The Cities and District will use the results of the drainage and flooding problem identification to
refine the existing proposed solutions and identify potential new solutions to better define and budget future
drainage improvement projects.
The Metro ADMP Update will:
•
Create a database of known flooding and drainage problems
•
Develop state-of-the-art models using updated technology and new aerial mapping
•
Assess flooding hazard and previously proposed solutions
•
Restudy the metro Phoenix floodplains
•
Prepare a plan to provide potential solutions for flood-prone areas
Water Management
Plan
Yes
Water Resource Plan, 2021 Update
Phoenix Water Services
Department
Impact on Risk Reduction:
Phoenix is reevaluating the strategic use of its available water supplies in consideration of changing climate
conditions, prolonged drought, and its own supply and demand modeling. There are many deficit mitigation
strategies available to Phoenix, falling generally into three categories: system infrastructure improvements and
regional collaboration to increase water use efficiency; demand management with additional water conservation
programs; and supply augmentation of the Phoenix water supply portfolio. It is likely that initiatives from all three
categories will be utilized during the planning period.
Open Space Plan
Yes
Open Space Element of the General
Plan
Planning and Development
Impact on Risk Reduction:
The Open Space element includes a description of the areas of Phoenix that provide public open space. These
areas provide space for recreation, environmental preservation, and natural hydrologic systems. It also includes
analysis of need; policies for management; and designated access points, protection, and acquisition strategies.
Community Forest
Management Plan
Yes
Shade Phoenix Plan
Parks and Recreation
Impact on Risk Reduction:
The Shade Phoenix Plan outlines the actions the City and its partners will take over the next five years to
accelerate the creation and enhance the maintenance of shade in Phoenix. The vision of the Shade Phoenix Plan
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Capability
in Place?
(Yes/No)
Name and Date
Department/Agency
Responsible
is that all community members experience the benefits of trees and built shade throughout the city. Actions in
the plan prioritize places in Phoenix where people are outside the most and populations most vulnerable to
extreme heat
Climate Change /
Sustainability Plan
Yes
2021 Climate Action Plan
Office of Environmental
Programs
Impact on Risk Reduction:
The City’s Climate Action Plan sets goals for emissions reductions and resiliency. The Plan is currently being
updated.
Transportation Plan
Yes
Transportation 2050
Street Transportation
Department, Public Transit
Department
Impact on Risk Reduction:
The Transportation 2050 plan was developed by a citizen-led committee of transportation experts and
community advocates and addresses a wide array of concerns expressed by residents who drive, bike, walk and
ride transit service. The 35-year citywide street and transit improvement plan, which became effective Jan. 1,
2016, will triple the number of light rail miles in Phoenix by adding 42 miles of across the city, provide late night
bus and Dial-a-Ride service citywide, and will directly and indirectly benefit every street in Phoenix.
The table below summarizes the emergency response and recovery plans that guide the City of Phoenix
to prepare for, respond to, and recover from flood hazard events.
Table 3-10. Emergency Response and Recovery Planning Capabilities
Plan Name
Capability
in Place?
(Yes/No)
Name and Date
Department/Agency
Responsible
Emergency Operations
Plan
Yes
City of Phoenix Major Emergency
Response and Recovery Plan
Emergency Management
Department
Impact on Risk Reduction:
The objective of the Emergency Operations Plan is to mobilize the resources of the entire Phoenix Fire
Department to an elevated level when circumstances require a commitment beyond normal capabilities. The
activation of this plan will cause the Fire Department Tactical Operations Center (TOC) to go into operation.
Identified Command Officers will respond to that location.
Threat & Hazard
Identification & Risk
Assessment (THIRA)
Yes
2015 City of Phoenix Threat and
Hazard Identification and Risk
Assessment
Emergency Management
Impact on Risk Reduction:
The THIRA identifies various threats, their impacts, and the City’s capabilities to address the risks from the
threats.
Dam Emergency
Action Plans (EAP)
Yes
Emergency Action Plans-
Street Transportation (Dams)
and Emergency Management-
Impact on Risk Reduction:
The EAPs for the different City and County dams in the area have been developed to support rapid response in
the event of an emergency. The EAPs provide different levels of response depending on the level of impounded
and/or risk to the structure. The documents are not publicly available due to the risk profile of each structure.
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The table below summarizes the codes, ordinances, and regulations that contribute to flood risk reduction
in the City of Phoenix.
Table 3-11. Codes, Ordinances, and Regulations Capabilities
Plan Name
Capability
in Place?
(Yes/No)
Code Citation (code chapter, date)
Department/Agency
Responsible
Building Code
Yes
2024 Phoenix Building Construction
Code
Planning & Development
Impact on Risk Reduction:
Building codes ensure that the design and construction of buildings meet optimal safety requirements and
standards.
Zoning Code
Yes
Chapter 41 Zoning
Planning & Development
Impact on Risk Reduction:
The state requires counties to adopt ordinances identifying zones for a particular purpose or residential area.
Zoning practices divide the county into land use zones as delineated on the official zoning maps and set
regulations for promoting citizens' health, safety, morals, convenience, and welfare.
The purpose of this Zoning Ordinance is to establish standards and regulations to govern the use of land and
structures in the City and for review and approval of all proposed development of property in the City, and to
provide a development review process that will be comprehensive, consistent, and efficient in the
implementation of the General Plan and other adopted goals, policies and standards of the City.
In order to conserve and promote the public health, safety and general welfare, and to aid in the harmonious,
orderly, and progressive development of the City, it is the intent of this ordinance that the development process in
the City of Phoenix be efficient, in terms of time and expense, effective, in proposed development and equitable,
in terms of consistency with established regulations and procedures, respect for the rights of property owners,
and the consideration of the interests of the citizens of the City. It is also the intent of this ordinance to preserve
and enhance aesthetic values, to encourage the most appropriate use of land, and to facilitate the adequate
provision of transportation, water, sewage treatment systems, schools, parks, and other public requirements
throughout the City.
Subdivision Regulations
Yes
Chapter 32 Subdivisions
Planning & Development
Impact on Risk Reduction:
Subdivisions provide for orderly growth and development that secures adequate provisions for water supply,
drainage, stormwater detention, sanitary sewerage, health and safety requirements, and protection from floods,
ensuring the identification of sufficient sites for schools, recreational areas, and public facilities.
The purpose of this chapter is to provide for the orderly growth and harmonious development of the City of
Phoenix; to ensure adequate traffic circulation through coordinated street systems with relation to major
thoroughfares, adjoining subdivisions, and public facilities; to achieve individual property lots of reasonable utility
and livability; to secure adequate provisions for water supply, drainage, sanitary sewerage, and other health
requirements; to ensure consideration for adequate sites for schools, recreation areas, and other public facilities;
to promote the conveyance of land by accurate legal description, and to provide logical procedures for the
achievement of this purpose.
Site Plan Review
Yes
Chapter 32 Subdivisions, Article II
Platting Procedures
Planning & Development
Impact on Risk Reduction:
The pre-application conference stage of subdivision planning comprises an investigatory period which precedes
actual preparation of preliminary plans by the subdivider. During this stage, the subdivider makes known his
intentions to the Planning and Development Department and is advised of specific public objectives related to
the subject tract and other details regarding platting procedures and requirements.
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Plan Name
Capability
in Place?
(Yes/No)
Code Citation (code chapter, date)
Department/Agency
Responsible
During this stage, it also may be determined that a change in zoning would be required for the subject tract or a
part thereof, and in such case the subdivider shall initiate the necessary rezoning application.
Stormwater
Regulations
Yes
Chapter 32C Stormwater Quality
Protection
City Manager
Impact on Risk Reduction:
The City Manager will regulate the use, grading, paving, maintenance, and operation of public rights-of-way and
public storm drain systems so as to reduce the discharge of pollutants, to the maximum extent practicable, that
may cause or contribute to either a violation of any applicable surface water quality standard or any condition of
a NPDES/AZPDES permit issued to the City, or any other act that causes or contributes to obstruction of or
damage to a public storm drain system. The City Manager may regulate the use of the public storm drain system
through administrative rules, permits, and other written forms of approval for activities that could release
pollutants or stormwater to a public storm drain system.
Floodplain Regulations
Yes
Chapter 32B Floodplains
Floodplain Administrator
Impact on Risk Reduction:
It is the purpose of this chapter to promote the public health, safety, and general welfare, and to minimize public
and private losses due to flooding in specific areas by provisions designed to:
A. Protect human life and health;
B. Minimize expenditure of public money for costly flood control projects;
C. Minimize the need for rescue and relief efforts associated with flooding and generally undertaken at
the expense of the general public;
D. Minimize prolonged business interruptions;
E. Minimize damage to public facilities and utilities such as water and gas mains; electric, telephone and
sewer lines; and streets and bridges located in special flood hazard areas;
F. Help maintain a stable tax base by providing for the sound use and development of special flood
hazard areas so as to minimize blight areas caused by flooding;
G. Participate in and maintain eligibility for flood insurance and disaster relief.
Any new buildings constructed in the SFHA must be elevated a minimum of one (1) foot above the Base Flood
Elevation (BFE) and must meet other stipulations in state and local ordinances.
Development and Permitting Capabilities
Identifying previous and future development trends is achieved through a comprehensive review of
permitting since completion of the previous plan and in anticipation of future development. Tracking
previous and future growth in potential hazard areas provides an overview of increased exposure to a
hazard within a community.
Table 3-12 summarizes development and permitting capabilities of the City of Phoenix.
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Table 3-12. Development and Permitting Capabilities
Development and Permitting Procedure
Comment
What department or outside agency is
responsible for issuing development
permits?
Planning & Development. A permit is required for all development
within the SFHA, not just the construction of buildings.
Is floodplain tracked in development
permits?
Yes, Floodplain Clearance Form
How does your jurisdiction inventory land
available for new development?
The City develops growth projections and land use assumptions.
What percentage of your jurisdiction is
available for new development?
Approximately 2/3 of the City has been developed, leaving 1/3
available for future development.
Administrative and Technical Capabilities
Administrative and technical capabilities focus on the availability of personnel resources responsible for
implementing all the facets of hazard mitigation. These resources include technical experts, such as
engineers and scientists, as well as personnel with capabilities that may be found in multiple departments,
such as grant writers. The table below summarizes the City of Phoenix departments, boards, and
committees that contribute to flood risk reduction.
Table 3-13. Departments, Boards, and Committees that Contribute to Flood Risk Reduction
Department / Board / Committee
Description and Role in Risk Reduction
Land Use Boards (Planning Board and
Zoning Board of Adjustment)
The Planning Commission makes recommendations to the City
Council on all matters that might be referred to it by the City
Council concerning or relating to a comprehensive plan of City
building and improvement and recommends to the City Council,
from time to time, amendments to the City Charter, ordinances
providing for the purchase of sites for City buildings; opening,
widening or other changes in streets and other public ways, and the
ornamentation of such sites, streets, grounds and other public
places; and such other ordinances as it may deem necessary and
proper in the premises and that may tend in connection with such
comprehensive plan to promote the public health, comfort, safety,
convenience, utility and welfare. The Planning Commission is also
authorized to confer and advise with other similar City planning
commissions or county planning commissions.
The Board of Adjustment hears and decides appeals of decisions
made by the Zoning Administrator in enforcement of the Zoning
Ordinance; hears and decides appeals from the action of the
Zoning Administrator in the granting or denying of variances, the
issuance of use permits, or in the interpretation of the provisions of
this ordinance; and hears and decides all matters referred to the
Board by the Zoning Administrator.
Planning Department
The Planning and Development Department guides the physical
development of the city by preserving our historic sites, planning
what can be built where, and ensuring safe construction of
buildings and infrastructure. A host of advisory and governing
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Department / Board / Committee
Description and Role in Risk Reduction
bodies of residents as well as elected officials provide oversight as
the city grows and needs arise. The process is governed through
the development and enforcement of city codes and ordinances.
Public Works
Public Works Department, Street Transportation
Construction / Building / Code
Enforcement Department
The Development Division of the Planning and Development
Department oversees plan review and inspections for all
components and phases of development and construction.
Engineering Department
Office of the City Engineer
Parks and Recreation Department
Parks and Recreation
Open Space Board / Committee
Parks and Recreation Board
Environmental Board / Commission
The purpose of the Environmental Quality and Sustainability
Commission is to identify environmental issues and problems
affecting the City of Phoenix and recommend to the City Council
appropriate roles for the City in addressing those issues or
problems in a manner which protects, restores, or enhances the
natural and urban environments.
Emergency Management / Public Safety
Department
The staff of the City of Phoenix Office of Homeland Security and
Emergency Management (OHSEM) protects communities by
coordinating and integrating all activities necessary before, during
and after any natural disasters, acts of terrorism, or other man-
made disasters.
Fire Department
The Phoenix Fire Department is committed to providing the highest
level of customer service and resources to our community and
members. The Department saves lives and protects property
through fire suppression, emergency medical and transportation
services, all-hazards incident management, and community risk
reduction efforts.
Additional departments, boards, and
committees
Office of Environmental Program’s (OEP) mission is to advance
environmental protection, regulatory compliance, and sustainability
by promoting sound environmental policies and practices through
leadership, training, and education. OEP is responsible for
coordinating environmental programs and issues, developing City
environmental policies and regulations, and providing technical and
regulatory assistance to all City departments, offices, and functions.
This includes climate change and surface water.
The table below summarizes the City of Phoenix’s staff with skills and expertise that contribute to flood
risk reduction.
Table 3-14. Technical/Staffing Capabilities
Staff
Description and Role in Flood Risk Reduction
Planners
Street Transportation Dept. – Deputy Director, Special Projects
Administrator, Principal Planner, Civil Engineers, Project Manager,
Principal Engineering Technicians, Chief Engineering Technicians;
Public Works Dept
Engineers
Street Transportation Dept. – Deputy Director, Special Projects
Administrator; Public Works Dept. – Assistant Director, Civil
Engineer III; Planning & Development Department – Deputy
Directors, Building Official, Plans Engineers
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Staff
Description and Role in Flood Risk Reduction
Emergency Manager
City Manager’s Office - Emergency Management Director
Stormwater Officer
•
The Stormwater Management Section (SWM) works in
cooperation with other City departments to coordinate the
City's stormwater management program and maintain
compliance with the Municipal Separate Storm Sewer
System (MS4) permit. SWM inspects industrial and
commercial facilities for compliance with Phoenix City Code
Chapter 32C, investigates illicit discharges to the storm
drain system, conducts wet-weather monitoring, and
conducts public outreach.
•
The Street Transportation Department is responsible for
maintenance of storm drains and washes, cleaning the
streets and catch basins, as well as creating maps of the
City's storm drain system.
•
The Planning and Development Department monitors
construction sites for stormwater compliance.
•
Public Works implements the Household Hazardous Waste
Collection Program and works with Keep Phoenix Beautiful
to
conduct
environmental
education
and
outreach
programs.
•
The Office of Environmental Programs coordinates city
employee training and evaluates City facilities and
construction activities for compliance with stormwater
requirements.
Resilience / Sustainability Officer
Chief Sustainability Officer
Grant Writer
Aviation Department – Planner II Fire Dept. – Volunteer Coordinator
and Fire Captains Planning Development Dept. – Principal Planner,
Planner III, Village Planner & Planner II Police Dept. – Police
Research Analysts Public Transit Dept Office of Emergency
Management – Management Assistant, Fire Dept. – Management
Assistant II, Street Transportation Dept. – Management Services,
Public Works Dept.
Staff with benefit / cost analysis expertise
Staff have undergone training.
Staff trained in conducting substantial
damage determinations
No
Staff trained in GIS
Information Technology Services – Info Tech
Analyst/Programmers and Info Tech Specialists Fire Dept. – Fire
Protection Engineer Planning Development Dept. – Senior GIS
Technician Police Dept. – Senior User Technology Specialist Street
Transportation Dept. - Info Tech Analyst/ Programmer II and Senior
GIS Technician Water Services Dept. – GIS and Senior GIS
Technicians
Scientist familiar with local natural
hazards
City Manager’s Office, Office of Environmental Programs –
Environmental Programs Coordinators and Environmental Quality
Specialists
Surveyors
Street Transportation Department – Survey Teams
NFIP Compliance and Floodplain Management Capabilities
Flooding is the costliest natural hazard in the United States and, with the promulgation of recent federal
regulation, homeowners throughout the country are experiencing increasingly high flood insurance
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premiums. Community participation in the NFIP opens up the opportunity for additional grant funding
associated specifically with flooding issues. Assessment of the jurisdiction’s current NFIP status and
compliance provides planners with a greater understanding of the local flood management program,
opportunities for improvement, and available grant funding opportunities.
The table below summarizes the floodplain administration capabilities of the City of Phoenix.
Table 3-15. NFIP Floodplain Administration Capabilities
Floodplain Administration
Comments
Provide an explanation of the jurisdiction’s NFIP
administration services (e.g. permit review, GIS,
education/outreach, inspections, engineering
capability)
Permit review, education/outreach, engineering
What local department is responsible for floodplain
management?
Floodplain Management, Office of the City Engineer
Are any staff certified floodplain managers (CFMs)?
Yes, several staff have CFM certification.
Does the jurisdiction maintain a list of properties that
have been damaged by flooding?
The City maintains the repetitive loss list and conducts
regular mailings to these properties.
Does the jurisdiction maintain a list of property owners
interested in flood mitigation?
No
How many properties have been mitigated (elevation
or acquisition)?
395 buildings have previously been mitigated
according to CRS record keeping.
Summarize the jurisdiction’s Substantial Damage
determination procedures.
Substantially damaged buildings (e.g., a residence
damaged so that the cost of repairs equals or exceeds
50% of the building’s value before it was damaged
must be elevated to or above the base flood elevation)
must meet the same construction requirements as a
new building.
Summarize the jurisdiction’s Substantial Improvement
procedures.
If the cost of reconstruction, rehabilitation, addition, or
other improvements to a building equals or exceeds
50% of the building’s market value, then the building
must meet the same construction requirements as a
new building.
When was the most recent Community Assistance
Visit (CAV) or Community Assistance Contact (CAC)?
2018
Does the jurisdiction’s administration of the floodplain
exceed NFIP requirements? (freeboard, mapping, etc.)
Yes, the City requires one foot of freeboard above the
BFE.
Public Education and Outreach Capabilities
Regular engagement with the public on issues regarding flood mitigation provides an opportunity to
directly interface with community members. Assessing this outreach and education capability illustrates
the connection between the government and community members, which opens a two-way dialogue that
can result in a more flood resilient community based on education and public engagement.
The table below summarizes the flood education and outreach capabilities of the City of Phoenix.
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Table 3-16. Education and Outreach Capabilities
Outreach Capability
Description and Role in Risk Reduction
Public warning system
Emergency warnings are delivered through the Community
Emergency Notification System (CENS), Wireless Emergency
Alerts (WEA), the Emergency Alert System (EAS) via radio and TV,
and the Outdoor Warning Siren System.
Public Information Officer
The City Communications Office provides residents and
employees with dynamic and interesting information about city
programs and services.
Website
The City website is phoenix.gov. Each City department has a
website page with personnel dedicated to its development and
maintenance.
The City has established a floodplain management website
within the Street Transportation website at: Floodplain
Management | City of Phoenix
Social media
The City has extensive social media capability that includes
Facebook, X (Twitter), YouTube, Instagram, Next Door, and
Linked In.
Newsletters
The City Communications Office produces a monthly residential
newsletter called PHX At Your Service, and a weekly employee
newsletter called PHX Connect.
Outreach campaigns
Water safety brochures and videos
Resident boards or commissions that could
address flood issues
The City has identified 15 Village Planning Committees.
Other outreach capabilities
PHX Newsroom, PHXTV
Fiscal Capabilities
Assessing a jurisdiction’s fiscal capability provides an understanding of the ability to fulfill the financial
needs associated with hazard mitigation projects. This assessment identifies both outside resources, such
as grant-funding eligibility, and local jurisdictional authority to generate internal financial capability, such
as through impact fees.
Table 3-17 summarizes the flood mitigation fiscal capabilities of the City of Phoenix.
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Table 3-17. Fiscal Capabilities
Financial Resource
Accessible
(Yes/No)
Comment and History of Use for Hazard Mitigation
FEMA Pre-Disaster Mitigation
Funding (FMA, PDM)
Yes
The City’s Hazard Mitigation Plan was updated in 2024 and
provides access to these grant programs.
FEMA Post-Disaster Mitigation
Funding (HMGP)
Yes
The City’s Hazard Mitigation Plan was updated in 2024 and
provides access to these grant programs.
Community Development
Block Grants (CDBG, CDBG-
DR)
Yes
Eligible
Capital improvements funding
Yes
The Capital Improvement Program for the City of Phoenix
represents a significant investment by the city in infrastructure.
Challenges exist in ensuring that this investment and resulting
infrastructure are deployed and maintained as efficiently as
possible given the vast area they are required to cover. For
example, the Street Transportation Department has to maintain
more than 4,800 miles of road every year. That’s the distance
from Phoenix to New York City and back (City of Phoenix 2015).
Open space acquisition
programs
Yes
Phoenix residents have continually demonstrated a commitment
to preserving and expanding the city’s open space network. In
2008, 83 percent of voters renewed the Phoenix Parks and
Preserve Initiative for 30 more years. The initiative sets aside one
cent of sales tax for every $10 of purchases to improve and
renovate existing parks, and to expand and improve the city’s
desert preserve system. Phoenician’s historic and continued
efforts to preserve and expand the city’s natural and manmade
open space networks speaks to the importance the concept of
creating an “oasis” has had in shaping what Phoenix is today. As
such, continuing to create and strengthen this oasis should be an
integral part of the city’s future (City of Phoenix 2015).
Impact fees for developers of
new homes
Yes
Eligible
User fees for water, sewer,
gas, or electric
Yes
Eligible
Stormwater utility fees
No
Eligible
Authority to levy taxes for
specific purposes
Yes
Eligible
Ability to incur debt through
bonds
Yes
Eligible
Participation in Other Programs
Other programs, such as the Community Rating System, NWS StormReady® Program, and Firewise USA®,
enhance a jurisdiction’s ability to mitigate, prepare for, and respond to flood related hazards. These
programs indicate a jurisdiction’s desire to go beyond minimum requirements set forth by local, state, and
federal regulations to create a more resilient community. These programs complement each other by
focusing on communication, mitigation, and community preparedness to save lives and minimize the
impact of flood hazards on a community.
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Table 3-18 summarizes the City of Phoenix’s participation in community classification programs.
Table 3-18. Community Classifications
Program
Participation Status /
Classification
Date Classified
FEMA Community Rating System (CRS)
Class 5
October 1, 2018
Building Code Effectiveness Grading Schedule
(BCEGS)
2/2
June 6, 2018
NWS StormReady® Program
Yes
-
NFPA Firewise USA®
No
-
Source(s): (FEMA 2025); (NWS n.d.); (NFPA 2024)
3.2
COORDINATION WITH COMMUNITIES AND AGENCIES
A total of 15 communities and agencies were contacted via email to participate in stakeholder outreach
interviews. During the interviews, stakeholders were asked to provide information for any recent, ongoing,
or future projects/activities with or adjacent to the City of Phoenix. Stakeholders were also given the
opportunity to opt in to review the Draft 2025 FMP document once it is available for stakeholder and public
review. Table 3-19 shows a summary of community and agency participation, followed by detailed
sections for each group.
Table 3-19: Community and Agency Participation
Agency or Organization Name
Participation
Arizona Department of Emergency and Military
Affairs
Invited to participate in stakeholder outreach interview.
Arizona Department of Transportation (ADOT)
Participated in stakeholder outreach interview. Provided
information on relevant transportation and stormwater projects.
Arizona Department of Water Resources
(ADWR)
Participated in stakeholder outreach interview.
Arizona State Land Department (ASLD)
Participated in stakeholder outreach interview.
Flood Control District of Maricopa County
(FCDMC)
Participated in stakeholder outreach interview.
Maricopa County Department of Emergency
Management (MCDEM)
Participated in stakeholder outreach interview.
National Weather Service (NWS)
Participated in stakeholder outreach interview.
Maricopa Association of Governments
Invited to participate in stakeholder outreach interview.
City of Scottsdale
Participated in stakeholder outreach interview. Provided
information on flood hazard mitigation project.
Town of Paradise Valley
Participated in stakeholder outreach interview.
Maricopa County Dept. of Transportation
(MCDOT)
Participated in stakeholder outreach interview.
Central Arizona Conservation Alliance (CAZCA)
Participated in stakeholder outreach interview. Provided website
for natural resource infrastructure.
Phoenix Mountains Preservation Council
Invited to participate in stakeholder outreach interview.
Arizona Forward
Participated in stakeholder outreach interview.
AZ Stormwater Outreach for Regional
Municipalities (STORM)
Participated in stakeholder outreach interview.
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Arizona Department of Transportation (ADOT)
Members of the Core Planning Team met with the ADOT on April 3, 2025. ADOT is responsible for the
numerous freeways (state routes and interstates) within the Phoenix area. ADOT and the City work very
closely on all projects within the City as the City has staff dedicated specifically to support coordination
with ADOT. Below is a list of the ongoing, recently complete, or future projects within the City, this is not
an all-encompassing list:
•
I-17 Storm Drain Project from Greenway Road to the Arizona Canal-Diversion Channel (ACDC)
o Completed
•
I-10 Broadway Curve
o Completion in mid- to late-2025
•
Loop 101 Widening
o Estimate completion date of early 2027
•
Scatter Wash ongoing maintenance
o Annual frequency done prior to monsoon season
•
New River and Deadman Wash Levee Inspections
o Annual frequency for visual inspections – currently completing a more detailed 5-year
inspection
•
Future development coordination around Loop 101 near Desert Ridge
•
Working with the City’s Water Services Department for a storm drain outlet for the 23rd Avenue
Wastewater Treatment Plant as it shares a headwall with ADOT.
The City works very closely with ADOT and will continue to do so in the future. With this close coordination,
all data is shared.
The ADOT requested and was provided with the Draft FMP for review prior to adoption.
Arizona Department of Water Resources (ADWR)
Members of the Core Planning Team met with the ADWR on April 8, 2025. ADWR does not have any
ongoing, recently complete, or future projects that impact the City with relation to stormwater, flooding, or
floodplains.
The ADWR requested and was provided with the Draft FMP for review prior to adoption.
Arizona State Land Department (ASLD)
Members of the Core Planning Team met with the ASLD on April 11, 2025. ASLD is working closely with
the City, FCDMC, and City of Scottsdale on the Rawhide Wash Channelization (Scottsdale) and Paradise
Ridge (Phoenix) flood control projects. The two projects are on either side of the municipal boundaries of
Phoenix and Scottsdale.
The ASLD is working directly with the City on Paradise Ridge and, therefore, all data has been shared
between parties. The project is estimated to be completed by the end of 2027.
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The ASLD requested and was provided with the Draft FMP for review prior to adoption.
Flood Control District of Maricopa County
Members of the Core Planning Team met with the FCDMC on March 19, 2025. The City and FCDMC work
very closely on different stormwater and flood control projects within the City. The FCDMC has done
several Area Drainage Master Studies and Plans (ADMS/P) that cover the City in the past and are currently
working on the Metro Phoenix ADMS/P which is estimated to be complete within the next two years.
Additionally, the FCDMC has completed hydrology and hydraulic modeling of South Mountain in the
Laveen, Hohokam, and Ahwatukee areas. Several stormwater projects have been completed in these areas
to mitigate flood hazards, such as the Laveen Area Conveyance Channel, storm drain projects along
Dobbins Road, and support for the development within the area.
The FCDMC requested and was provided with the Draft FMP for review prior to adoption.
Maricopa County Department of Emergency Management (MCDEM)
Members of the Core Planning Team met with the MCDEM on April 29, 2025. No recent, ongoing, or future
projects are planned with the City.
The MCDEM requested and was provided with the Draft FMP for review prior to adoption.
National Weather Service
Members of the Core Planning Team met with the National Weather Service on March 28, 2025. The
National Weather Service does not work directly with the City but is continuously working to improve
thresholds for warnings and situational awareness for the Maricopa County and surrounding area.
All information from the National Weather Service is available publicly.
The National Weather Service requested and was provided with the Draft FMP for review prior to adoption.
City of Scottsdale
Members of the Core Planning Team met with the City of Scottsdale on April 2, 2025. The City of Scottsdale
has recently completed the Rawhide Wash Flood Hazard Mitigation Project which included channelization,
new levees and embankments, and floodplain delineation updates are pending. This project ties into the
downstream City of Phoenix project for Paradise Ridge.
The City of Scottsdale requested and was provided with the Draft FMP for review prior to adoption.
Town of Paradise Valley
Members of the Core Planning Team met with the Town of Paradise Valley on April 10, 2025. The Town of
Paradise Valley has locations that outfall into the City of Phoenix. The Town is currently working on the
development of a Stormwater Master Plan and is expecting it to be complete at the end of June 2025. The
Town will have information to share about the plan upon its completion.
The Town of Paradise Valley requested and was provided with the Draft FMP for review prior to adoption.
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Maricopa County Department of Transportation (MCDOT)
Members of the Core Planning Team met with MCDOT on April 16, 2025. MCDOT has no ongoing projects
that are stormwater or floodplain related within or adjacent to the City of Phoenix.
MCDOT requested and was provided with the Draft FMP for review prior to adoption.
Central Arizona Conservation Alliance (CAZCA)
Members of the Core Planning Team met with the CAZCA on April 2, 2025. CAZCA currently has no recent,
ongoing, or future projects within the City of Phoenix. A web map of natural resource infrastructure is
publicly available to support public education (https://web.tplgis.org/cazca_plan/).
CAZCA requested and was provided with the Draft FMP for review prior to adoption.
Arizona Forward
Members of the Core Planning Team met with Arizona Forward on April 14, 2025. Arizona Forward has no
recent, ongoing, or future projects within the City of Phoenix. Arizona Forward requested and was provided
with the Draft FMP for review prior to adoption.
AZ STORM
Members of the Core Planning Team met with AZ STORM on April 15, 2025. AZ STORM does public
outreach with a focus on stormwater pollution and quality.
AZ STORM requested and was provided with the Draft FMP for review prior to adoption.
4 | Step 4: Assess the Hazard
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4
STEP 4: ASSESS THE HAZARD
4.1
WHAT ARE THE FLOOD HAZARDS?
Defining the flood hazards that present the greatest risk to the planning area is the first step in assessing
overall risk to the community. The FMP Committee reviewed available information to determine what types
of flood hazards may affect the planning area, how often they occur, and their potential severity.
4.2
FEDERAL DISASTER DECLARATIONS
Federal disaster declarations are typically issued for hazard events that cause more damage than state
and local governments can handle without assistance from the federal government, although no specific
dollar loss threshold has been established for these declarations. A presidential disaster declaration puts
federal recovery programs into motion to help disaster victims, businesses, and public entities. Some of
the programs are matched by state programs. There are two types of disaster declarations provided for in
the Stafford Act: Emergency Declarations and Major Disaster Declarations. Both declaration types are
declared at the county level and authorize the President to provide supplemental federal disaster
assistance (FEMA 2011).
•
Emergency Declaration: An Emergency Declaration can be declared for any occasion or instance
when the President determines federal assistance is needed. Emergency Declarations supplement
State and local efforts in providing emergency services, such as the protection of lives, property,
public health, and safety, or to lessen or avert the threat of a catastrophe in any part of the United
States.
•
Major Declaration: The President can declare a Major Disaster Declaration for any natural event,
including any hurricane, tornado, storm, high water, wind-driven water, tidal wave, tsunami,
earthquake, volcanic eruption, landslide, mudslide, snowstorm, or drought, or, regardless of cause,
fire, flood, or explosion, that the President believes has caused damage of such severity that it is
beyond the combined capabilities of state and local governments to respond. A major disaster
declaration provides a wide range of federal assistance programs for individuals and public
infrastructure, including funds for both emergency and permanent work.
Review of presidential disaster declarations helps establish the probability of reoccurrence for hazards and
identify targets for risk reduction. Disaster declarations are made at the county level.
Table 4-1 summarizes the federal disaster declarations involving floods that included Maricopa County
since 1954. Out of 26 total presidential declarations, 12 involved flooding, 11 involved wildfires, and 2
involved the COVID-19 pandemic. One declaration was related to national efforts to support evacuations
during and after Hurricane Katrina in the Gulf region, showing that the City of Phoenix can be indirectly
impacted by floods that take place well outside of its jurisdictional boundaries.
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Table 4-1. Federal Disaster Declaration Involving Flood in Maricopa County
Disaster Number
Event Date(s)
Declaration Date
Title
DR-217-AZ
April 30, 1966
April 30, 1966
Arizona Flooding
DR-294-AZ
September 22, 1970
September 22, 1970
Arizona Heavy Rains, Flash
Floods
DR-343-AZ
July 3, 1972
July 3, 1972
Arizona Severe Storms,
Flooding
DR-551-AZ
March 4, 1978
March 4, 1978
Arizona Severe Storms,
Flooding
DR-570-AZ
December 21, 1978
December 21, 1978
Arizona Severe Storms,
Flooding
DR-614-AZ
February 19, 1980
February 19, 1980
Arizona Severe Storms,
Flooding
DR-884-AZ
July 8 – September 14,
1990
December 6, 1990
Arizona Flooding, Severe
Storm
DR-977-AZ
January 5 – March 6,
1993
January 19, 1993
Arizona Severe Storms,
Tornadoes, Flooding
DR-1304-AZ
September 14 - 23, 1999
October 15, 1999
Severe Storms, High Winds
and Flooding in Arizona
DR-1347-AZ
October 21 – November
8, 2000
October 27, 2000
Severe Storms and Flooding
in Arizona
DR-1586-AZ
February 10-15, 2005
April 14, 2005
Arizona Severe Storms and
Flooding
DR-4203-AZ
September 7-9, 2014
November 5, 2014
Arizona Severe Storms and
Flooding
Source: (FEMA 2025)
4.3
NATIONAL RISK INDEX
FEMA’s National Risk Index (NRI) is a dataset and online tool developed to help illustrate risk for 18 natural
hazards. The NRI leverages available source data for natural hazard and community risk factors to develop
a baseline risk measurement for each county in the United States. The NRI ranks riverine flooding as
relatively moderate for the Maricopa County and the City of Phoenix (FEMA 2024a).
4.4
EVALUATION OF FLOOD HAZARDS
The FMP Committee evaluated the various flood hazards that the City of Phoenix is exposed to, reviewed
previous disaster declarations, the NRI, the hazards of concern in the 2016 Phoenix FMP, the hazards of
concern in the 2020 Floodplain Management Plan for Unincorporated Maricopa County, the hazards of
concern in the 2021 Maricopa County Multi-Jurisdictional Hazard Mitigation Plan, the hazards of concern
in the 2023 State of Arizona Hazard Mitigation Plan, recent hazard events/changes in exposure, and
current CRS FMP guidance before finally determining which hazards of concern should be included in the
2025 FMP.
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Table 4-2. Identification of Flood Hazards of Concern for the City of Phoenix, AZ
Flood Hazard
Comments
To Be Included in 2025
Phoenix FMP update?
Alluvial Fan Flooding
The City of Phoenix is exposed to alluvial fan flooding
along and near sloped areas.
Yes
Coastal Erosion
The City of Phoenix is located well inland and is not
exposed to coastal erosion.
No
Dam Failure
According to the USACE National Dam Inventory, the
City of Phoenix could be directly and indirectly
impacted by dam failure.
Yes
Debris Flow
While debris flows are common following wildfire
events in Maricopa County, debris flows typically take
place outside of the City of Phoenix boundaries.
No
Flash Flooding
Flash flooding is common in the City of Phoenix and
typically occurs within the Special Flood Hazard Area.
Yes, discussed with riverine
flooding.
Levee Failure
According to the USACE National Levee Database,
there are 14 levees located in the City of Phoenix.
There are approximately 59 total levee systems in the
Phoenix metro area that could impact the City directly
or indirectly.
Yes
Riverine Flood
The NRI ranks riverine flooding as relatively moderate
for the City of Phoenix. Riverine flooding is mapped
using the Special Flood Hazard Area.
Yes
Sheet Flow
Sheet flow has been identified as a past flooding type.
It is included in mapping for the Special Flood Hazard
Area (AO zones).
Yes, discussed with riverine
flooding.
Storm Surge
Although the City of Phoenix may be impacted by
remnants of tropical cyclones, the City is located well
inland and is not exposed to storm surge.
No
Tsunami
The City of Phoenix is located well inland and is not
exposed to tsunamis.
No
Urban Flooding
Although urban flooding is not mapped, the City is
exposed to urban flooding.
Yes
Source(s):
(USACE 2025); (USACE 2025) (FEMA 2024a).
4.5
FLOOD HAZARDS OF CONCERN FOR THE 2025 FLOODPLAIN MANAGEMENT
PLAN
Based on input from the FMP Committee, the following flood hazards were identified as affecting the City
of Phoenix and will be addressed in the 2025 FMP:
•
Riverine flooding (includes sheet flow)
•
Alluvial fan flooding
•
Urban flooding
•
Dam and levee failure flooding
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4.5.1
Changes from the 2021 Maricopa County Multi-jurisdictional Hazard
Mitigation Plan
For the 2025 FMP, the City of Phoenix returned to a stand-alone Floodplain Management Plan. This
resulted in establishment of a FMP Committee to guide an update of the plan focusing only on flood
hazards that directly and indirectly impact the City of Phoenix.
4.6
ASSESSING RISK
In hazard mitigation planning, risk is the potential for damage or loss when natural hazards interact with
people or assets, such as buildings, infrastructure, and resources. A risk assessment is a process used to
identify potential hazards and analyze what could happen if a disaster or hazard occurs. It involves a data-
driven analysis to identify potential hazards, what could happen if hazards occur, and determine
vulnerabilities to hazards (FEMA 2023).
The risk assessment process focuses on three main elements – hazard identification, exposure
identification, and vulnerability identification and loss estimation.
4.7
RISK ASSESSMENT TOOLS
For this FMP, previously developed risk assessment data from the 2021 Maricopa County Multi-
Jurisdictional Hazard Mitigation Plan and updated 2025 data from the USACE National Levee Database
were used to conduct the risk assessment.
4.7.1
Mapping
Floodplain mapping from the 2021 Maricopa County Multi-Jurisdictional Hazard Mitigation Plan was used
to analyze the location of flood hazards for riverine flooding (Special Flood Hazard Area), dam failure
flooding (emergency spillway and potential dam failure flood hazard areas), and levee failure flooding
(potential levee failure flood hazard area)
4.7.2
Critical Facilities
For critical facilities identified by the 2021 Maricopa County Multi-Jurisdictional Hazard Mitigation Plan,
critical facilities followed the criteria set forth by the Critical Infrastructure Assurance Office (CIAO). The
State of Arizona has adopted eight general categories that define critical facilities and infrastructure
(Maricopa County 2021):
•
Communications Infrastructure: Telephone, data services, and internet communications, cell and
radio towers, which have become essential to continuity of business, industry, government, and
military operations.
•
Electrical Power Systems: Generation stations and transmission and distribution networks that
create and supply electricity to end-users.
•
Gas and Oil Facilities: Production and holding facilities for natural gas, crude and refined petroleum,
and petroleum-derived fuels, as well as the refining and processing facilities for these fuels.
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•
Banking and Finance Institutions: Banks, financial service companies, payment systems, investment
companies, and securities/commodities exchanges.
•
Transportation Networks: Highways, railroads, ports and inland waterways, pipelines, and airports
and airways that facilitate the efficient movement of goods and people.
•
Water Supply Systems: Sources of water; reservoirs and holding facilities; aqueducts and other
transport systems; filtration, cleaning, and treatment systems; pipelines; cooling systems; and
other delivery mechanisms that provide for domestic and industrial applications, including systems
for dealing with water runoff, wastewater, and firefighting.
•
Government Services: Capabilities at the federal, state, and local levels of government required to
meet the needs for essential services to the public.
•
Emergency Services: Medical, police, fire, and rescue systems.
Other assets such as public libraries, schools, museums, parks, recreational facilities, historic buildings or
sites, churches, residential and/or commercial subdivisions, apartment complexes, and so forth, were
classified as non-critical facilities and infrastructure, as they are not necessarily “critical” per the definition
set forth in Executive Order 13010. They were, however, still considered by the Maricopa County Multi-
Jurisdictional Hazard Mitigation Plan Planning Team to be important facilities, and critical and non-critical
should not be construed to equate to important and non-important. For each asset, attributes such as
name, description, physical address, geospatial position, and estimated replacement cost were identified
to the greatest extent possible and entered into a GIS geodatabase (Maricopa County 2021).
For levee failure, information on critical facilities was identified using the USACE National Levee Database.
The National Levee Database uses the DHS Homeland Infrastructure Foundation-Level Data (HIFLD) from
2023 to determine critical facility designation and location (USACE n.d.).
4.7.3
Exposure
Potential exposures reported in this Plan represent an inherent assumption that the hazard occurs county-
wide to the magnitude shown on the hazard profile map. The results are intended to present a county-wide
value and number of exposures. Any single hazard event is unlikely to impact the entirety of the hazard
profile map established for the City and the event specific exposure and losses would be some fraction of
those estimated herein (Maricopa County 2021).
For exposure data provided by the 2021 Maricopa County Multi-Jurisdictional Hazard Mitigation Plan,
asset exposure estimates were accomplished by intersecting the asset inventory with the flood hazard
areas and compiling the exposed facility count and replacement values. Similarly, human population and
residential unit exposures were estimated by intersecting the same hazards with the census block
population and residential unit count data sets. Structure and content replacement costs for assets were
assigned to each facility by the corresponding jurisdiction. Structure and content replacement costs for
the residential housing counts were geographically assigned based on zip code and average housing cost
unit values data from the Zillow home value database. Content value for these buildings was assumed to
equal 50% of the replacement cost (Maricopa County 2021).
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Combining the exposure results from the asset inventory and census database provided a comprehensive
depiction of the overall exposure of critical facilities, human population, and residential building stock and
the two datasets were considered complimentary and not redundant (Maricopa County 2021).
Levee failure exposure was determined based on information provided by the USACE National Levee
Database (USACE n.d.).
4.8
RISK ASSESSMENT APPROACH
This plan evaluated risks associated with each identified hazard for the City of Phoenix. Each flooding type
was profiled using the following steps:
•
Description of the Hazard: Defining the hazard and a discussion of potential impacts
•
Location: Geographic areas most affected by the hazard
•
Extent: Measuring the intensity of the hazard, warning time for preparations, and the reasonable
worst-case scenario
•
Previous Occurrences: Summary of past events that have impacted the planning area
•
Future Conditions: Probability estimates, including potential frequency and intensity shifts caused
by climate change and population and development trends
For each flooding type, one of the following assessment approaches was used, depending on the type of
information available for the hazard:
•
Quantitative assessment—Performed when numerical data are available to define risk. Available
numerical hazard data may include the financial impact and probability
•
Qualitative assessment—Uses words to describe and categorize the likelihood and consequences
of a risk when numerical data are unavailable
Vulnerability of exposed structures and infrastructure was evaluated by estimating the probability of
occurrence of flooding and assessing structures, facilities, and systems that are exposed to each flood
hazard.
•
Impact on Life, Health, and Safety
•
Impact on General Building Stock
•
Impact on Community Lifelines
•
Impact on the Economy
•
Impact on Historic and Cultural Resources
•
Impact on Ecosystems and Natural Resources
•
Change in Vulnerability Since the Previous 2021 HMP
4.9
SOURCES OF DATA USED IN RISK ASSESSMENT
The vulnerability assessment results from the 2021 Maricopa County Multi-Jurisdictional Hazard
Mitigation Plan and information from the USACE National Levee Database were used to assess the City of
Phoenix’s vulnerabilities to flooding.
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Riverine and alluvial fan flooding impacts were collectively analyzed based on exposure to high hazard
flood zones. Urban flooding was discussed qualitatively as all of the City of Phoenix could potentially
experience urban flooding. Dam failure was analyzed based on exposure to emergency spillway inundation
and potential inundation from medium and high hazard dams. Levee failure was analyzed based on
population and assets protected by levees identified in the USACE National Levee Database.
4.10
DATA LIMITATIONS
Although the City of Phoenix and Maricopa County have a wealth of available data, data limitations did limit
the assessment of risk for some hazards. Data limitations include the following:
•
The 2021 Maricopa County Multi-Jurisdictional Hazard Mitigation Plan used 2010 census
residential structure statistics.
•
No industrial or commercial unit estimates are made for this update due to the lack of reliable data
at the time of the 2021 Maricopa County Multi-Jurisdictional Hazard Mitigation Plan analysis.
4.11
FLOOD HAZARD PROFILE
For this 2025 Floodplain Management Plan, the flood hazard was determined to include the following sub-
hazards: riverine flooding, alluvial fan flooding, urban flooding, and dam and levee failure.
4.11.1
Description of the Hazard
Defining the Hazard
Riverine Flooding
Riverine flooding, or fluvial flooding, is when streams and rivers exceed the capacity of their natural or
constructed channels to accommodate water flow and water overflows the banks, spilling out into
adjacent low-lying, dry land. This occurs when the flow of a river exceeds the bank sides and causes
damage or obstruction to a nearby floodplain. Riverine flooding can turn into a flash flood if the river is at
or above its flood stage and if the soil is saturated (FEMA 2019).
A flash flood is a rapid inundation of low-lying areas caused by heavy rain associated with severe
thunderstorms, tropical systems, or melting water from ice or snow. Flash flooding also occurs far away
from water bodies when a large volume of water cannot be absorbed by the soil or stormwater systems
and travels overland unimpeded (NWS 2019).
Sheet flow is a type of flood hazard with flooding depths of 1 to 3 feet that occurs in areas of sloping land
(FEMA 2020). Depending on the slope of the land, there can also be ponding, and the sheet flow can be
slow or move fast enough to cause erosion (Arizona Department of Emergency and Military Affairs 2023).
Alluvial Fan Flooding
Active alluvial fans can develop at locations where steep mountain washes abruptly transition to flatter
alluvial piedmonts located at the base of the mountain. During flood events, the steep washes carry heavy
sediment loads that deposit in a fan shape, with one or more primary flow paths of concentrated flooding
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that can change location across the fan face with any given flood event. The point of slope changes at the
upper-most portion of the fan is known as the fan apex. Alluvial fans are active and volatile in moving the
primary channel(s) and creating new flow paths (Arizona Department of Emergency and Military Affairs
2023).
Urban Flooding
Flood issues are traditionally associated with riverine and coastal areas, but increasing attention is being
given to urban flooding, where flood risk is more a function of the human-built environment. Population
growth and associated development in metropolitan areas, combined with aging stormwater
infrastructure and changing weather patterns, have given rise to an urban-specific flood problem of
national importance. In this new category of flooding, risk and impacts are no longer tied to the FEMA-
defined floodplains. Instead, significant flood losses can occur miles from a delineated floodplain where
these urban losses are embedded in a highly developed landscape (Center for Disaster Resilience, Center
for Texas Beaches and Shores 2018).
Local (urban) drainage systems collect groundwater from heavy rainfall in developed areas. Water that
does not evaporate or become absorbed by the ground is carried by conduits to waterways such as creeks,
rivers, or the ocean. These systems have two purposes: 1) to control storm water runoff during periods of
heavy rainfall; and 2) to minimize disruption of activity from more frequently occurring, less significant
storms. Flooding occurs when runoff exceeds system capacity, or because systems are blocked from lack
of maintenance. Flooding that is the result of poorly designed or blocked drainage systems is categorized
as urban/stormwater flooding (NOAA 2022).
Dam and Levee Failure Flooding
A dam is an artificial barrier that has the ability to impound water, wastewater, or any liquid-borne material
for the purpose of storage or control of water (FEMA 2019). They are built for the purpose of power
production, agriculture, water supply, recreation, and flood protection. Dam failure is any malfunction or
abnormality outside of the design that adversely affects a dam’s primary function of impounding water.
Dams can fail for one or a combination of the following reasons (FEMA 2018):
•
Overtopping caused by floods that exceed the capacity of the dam or levee (inadequate spillway
capacity);
•
Prolonged periods of rainfall and flooding;
•
Deliberate acts of sabotage (terrorism);
•
Structural failure of materials used in dam construction;
•
Movement and/or failure of the foundation supporting the dam;
•
Settlement and cracking of concrete or embankment dams;
•
Piping and internal erosion of soil in embankment dams;
•
Inadequate or negligent operation, maintenance, and upkeep;
•
Failure of upstream dams on the same waterway; or
•
Earthquake (liquefaction / landslides).
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Potential for catastrophic flooding caused by dam failures led to enactment of the National Dam Safety
Act (Public Law 92-367), which for 30 years has protected Americans from dam failures. The National Dam
Safety Program (NDSP) is a partnership among states, federal agencies, and other stakeholders that
encourages individual and community responsibility for dam safety. Under FEMA’s leadership, state
assistance funds have allowed all participating states to improve their programs through increased
inspections, emergency action planning, and purchases of needed equipment. FEMA has also expanded
existing and initiated new training programs. Grant assistance from FEMA provides support for
improvement of dam safety programs that regulate most dams in the United States (FEMA n.d.).
The U.S. Army Corps of Engineers (USACE) is responsible for safety inspections of some federal and
nonfederal dams in the United States that meet the size and storage limitations specified in the National
Dam Safety Act. USACE has inventoried dams and has surveyed each state’s and federal agency’s
capabilities, practices, and regulations regarding design, construction, operation, and maintenance of the
dams. USACE has also developed guidelines for inspection and evaluation of dam safety (USACE 2021).
Arizona’s Dam Safety Program has existed since 1929. Funding for the program was minimal and sporadic
until legislative approval of a consistent budget began in 1971, authorizing permanent staffing and the
development of a comprehensive statewide Dam Safety Program (Arizona Department of Emergency and
Military Affairs 2023).
The Arizona Revised Statutes (A.R.S.) §45-1201 assigns the responsibility for supervision of the safety of
non-federal dams to the Director of the Arizona Department of Water Resources (ADWR). The mission of
the ADWR Dam Safety Section is to maximize the protection of the public against loss of life and property
by reducing the likelihood of catastrophic failure of dams within the state’s jurisdiction. State statute
defines a jurisdictional dam as an artificial barrier for the impounding or diversion of water either 25 feet
or more in height or having a storage capacity of more than 50 acre-feet, with the following exceptions
(Arizona Department of Emergency and Military Affairs 2023):
•
Any barrier for the purpose of storing liquid-borne material (e.g., mine tailings dams);
•
Any barrier that is a “release-contained barrier;”
•
Any barrier that is federally owned and operated;
•
Sole use of transportation structures;
•
Any barrier that is:
•
Less than six feet in height, regardless of storage capacity, or
•
Between six and 25 feet in height with a storage capacity of less than 50 acre-feet, or
•
Greater than 25 feet in height with 15 acre-feet or less of storage capacity.
•
For an artificial barrier and/or appurtenant works structure to be considered a "release-contained
barrier," the following criteria should comply:
•
Has storage capacity that in the event of failure would be contained within the property that the
release-contained barrier owner owns controls, operates, maintains, or manages.
•
The property on which the release would be contained is not open to the public.
•
The owner will maintain downstream containment structures or sites with sufficient containment
throughout the useful life of the release-contained barrier.
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The National Flood Insurance Program (NFIP) defines a levee in Title 44, Chapter 1, Section 59.1 of the
Code of Federal Regulations (44 CFR 59.1) as “a man-made structure, usually an earthen embankment,
designed and constructed in accordance with sound engineering practices to contain, control, or divert the
flow of water so as to reduce risk from temporary flooding.” The NFIP regulations define a levee system
as “a flood protection system which consists of a levee, or levees, and associated structures, such as
closure and drainage devices, which are constructed and operated in accordance with sound engineering
practices” (FEMA 2020).
Levees are designed to reduce flood risk from flooding events; however, they do not eliminate the risk
entirely. It is always possible that a flood will exceed the capacity of a levee, no matter how well the
structure is built. Levees are designed to manage a certain amount of floodwater and can be overtopped
or fail during flood events exceeding the level for which they were designed. Levee failures can also be
caused by structural failures resulting from improper maintenance, inadequate foundations, seismic
activity, erosion, seepage, or burrowing animals. When a levee fails, the result can be more catastrophic
than if the levee had never been constructed (FEMA 2020).
Levees and floodwalls are typically built parallel to a waterway, most often a river, to reduce the risk of
flooding on the landward side. Floodwalls, which are typically made of concrete or steel, are often
constructed on a levee crown to increase the height of the levee, without increasing the base of the
embankment (FEMA 2020).
In 2007, Congress established the National Committee on Levee Safety (NCLS) to develop
recommendations for a National Levee Safety Program (NLSP). The NCLS, with guidance from Congress,
developed the following definition for a levee: “A manmade barrier (embankment, floodwall, or structure)
along a watercourse constructed for the primary purpose to provide hurricane, storm, and flood protection
relating to seasonal high water, storm surges, precipitation, and other weather events; and that normally is
subject to water loading for only a few days or weeks during a year. Levees also may be embankments,
floodwalls and structures that provide flood protection to lands below sea level and other lowlands and
that may be subject to water loading for much, if not all, portions of the year, but that do not constitute
barriers across watercourses or constrain water along canals” (Arizona Department of Emergency and
Military Affairs 2023).
Cause of the Hazard
Flooding can occur for a variety of reasons. Floods can happen during and after heavy rains, when snow
quickly melts, or when dam or levees break (NOAA National Severe Storms Laboratory 2023).
There are three seasonal atmospheric conditions that tend to trigger significant flood events in Arizona
(Arizona Department of Emergency and Military Affairs 2023):
•
Tropical Storm Remnants: Historically, the most regionally severe flooding occurs when remnants
of hurricanes and tropical storms enter the state. These events infrequently occur (i.e.,
approximately every ten years), mostly in early autumn, and can bring several days of prolonged,
intense precipitation events covering large regions that can cause severe flooding. In general, the
flood hazard imposed by tropical storm remnants tends to degrade with northern movement
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through the state. The southern and central regions of the State of Arizona, including the City of
Phoenix, are usually impacted the most.
•
Winter Rains: Winter brings the threat of low-intensity, long-duration rains that cover large areas
and cause extensive flooding and erosion, particularly when combined with snowmelt that
increases runoff after rain falls on significant snowpack. The El Nino climate phenomenon can
influence winter storms and cause severe flooding. Winter rains tend to impact the northern regions
of the State of Arizona.
•
Summer Monsoons: Monsoon winds bring humid subtropical air into the state in mid to late
summer. Solar heating triggers afternoon thunderstorms that can be devastating. Flash flooding
may occur as a result of local, intense rainfall in a short period (usually six hours). Many Arizona
communities get half of their annual rainfall during the summer monsoon from June 15 to
September 30. Summer monsoons impact areas statewide but tend to be strongest in southern
and central regions of the State of Arizona, including the City of Phoenix.
Summary of Potential Impacts
Flooding can result in severe damages. Hydrostatic pressures and flowing floodwaters can easily cause
structures to collapse or float away. Flooding can result in scouring and erosion of sediment in areas with
flow or wave action. Floodwater can lead to drownings and the spread of contaminants and disease.
Cascading Hazard Impacts
Flooding can result in the scouring and erosion of soil, utility failures, hazardous material releases, and the
spread of disease.
4.11.2
Location
Flooding potential is influenced by climatology, meteorology, and topography. Most floods occur within
floodplains. A floodplain is defined as the land adjoining the channel of a river, stream, ocean, lake, or other
watercourse or water body that becomes inundated with water during a flood. The floodplain describes
the area inundated by the “100-year” flood, or a flood that has a 1-percent chance in any given year of being
equaled or exceeded. A floodplain is designated when floodwater exceeds the capacity of the main
channel, or water escapes the channel through bank erosion. Figure 4-1 depicts the flood hazard area, the
flood fringe, and the floodway areas of a floodplain.
The boundaries of the floodplains are altered as a result of changes in land use, the amount of impervious
surface, placement of obstructing structures in floodways, changes in precipitation and runoff patterns,
improvements in technology for measuring topographic features, and utilization of different hydrologic
modeling techniques.
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Figure 4-1 Characteristics of a Floodplain
Source: (FEMA 2009)
Flood hazard areas are identified as Special Flood Hazard Area (SFHA). SFHA are defined as the area that
will be inundated by the flood event having a 1-percent chance of being equaled to or exceeded in any given
year. The 1- percent annual chance flood is also referred to as the base flood or 100-year flood. A 100-year
floodplain is not a flood that will occur once every 100 years; the designation indicates a flood that has a
1-percent chance of being equaled or exceeded each year. Thus, the 100-year flood could occur more than
once in a relatively short period of time. Similarly, the moderate flood hazard area (500-year floodplain) will
not occur every 500 years but is an event with a 0.2-percent chance of being equaled or exceeded each
year. The 1-percent annual chance floodplain establishes the area that has flood insurance and floodplain
management requirements. The following are additional definitions relating to flood maps (FEMA 2025):
•
Flood hazard areas identified on the Flood Insurance Rate Map are identified as a Special Flood
Hazard Area (SFHA).
•
SFHA = the area that will be inundated by the flood event having a 1-percent chance of being
equaled or exceeded in any given year.
•
1-percent annual chance flood = the base flood or 100-year flood.
•
SFHAs are labeled as Zone A, Zone AO, Zone AH, Zones A1-A30, Zone AE, Zone A99, Zone AR, Zone
AR/AE, Zone AR/AO, Zone AR/A1-A30, Zone AR/A, Zone V, Zone VE, and Zones V1-V30.
•
Zone B or Zone X (shaded) = Moderate flood hazard areas and are the areas between the limits of
the base flood and the 0.2-percent-annual-chance (or 500-year) flood.
•
Zone C or Zone X (unshaded) = Areas of minimal flood hazard, which are the areas outside the
SFHA and higher than the elevation of the 0.2-percent-annual-chance flood, are labeled.
Copies of FEMA’s flood mapping for the City of Phoenix on file at City Hall. The City’s floodplain
management
page
(https://www.phoenix.gov/administration/departments/city-engineer/floodplain-
management.html) also has links to floodplain mapping available from the Maricopa County Flood Control
District and the National Flood Hazard Layer.
Figure 4-2 through Figure 4-4 display Special Flood Hazard Areas for the City of Phoenix.
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Figure 4-2 City of Phoenix Special Flood Hazard Area Map - North
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Figure 4-3 City of Phoenix Special Flood Hazard Area Map - Central
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Figure 4-4 City of Phoenix Special Flood Hazard Area Map - South
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Riverine Flooding
In the City of Phoenix, floodplains line the rivers, washes, and canals of the City. Canals weave through
metro Phoenix and provide residents of the Valley with year-round access to water. One-hundred eighty
miles of canals bring water to 2.5 million people in the region. Managed today by Salt River Project (SRP),
the canals primarily serve the crucial function of managing water, but also have been a place for recreation,
past and present (MPact 2023). Areas bordering the City’s natural and manmade waterways are prone to
riverine flooding. When the carrying capacity of these waterways are exceeded, they overflow their banks,
causing riverine flooding.
High hazard flood zones throughout Phoenix are primarily located along established watercourses,
conveyance corridors, canals, and flood control facilities (Maricopa County 2021).
Special Flood Hazard Areas within the City area are typically along washes or rivers or along the upstream
side of an embankment. Flooding in these areas comes from significant rainfall events throughout the City
and surrounding areas. Velocities and warning times would vary depending on the location and size of the
storm event. In the northern part of the City, storm events may occur in the mountains to the north, and
velocities would be high, but the warning time would be increased due to the location of the storm event.
Within the City, flood control dams and levees have reduced the risk to people and property along Special
Flood Hazard Areas.
Alluvial Fan Flooding
Alluvial fan flooding is a type of flood hazard that occurs only on alluvial fans. It is characterized by flow
path uncertainty so great that this uncertainty cannot be set aside in realistic assessments of flood risk or
in the reliable mitigation of the hazard. An alluvial fan flooding hazard is indicated by three related criteria:
(a) flow path uncertainty below the hydrographic apex, (b) abrupt deposition and ensuing erosion of
sediment as a stream or debris flow loses its competence to carry material eroded from a steeper,
upstream source area, and (c) an environment where the combination of sediment availability, slope, and
topography creates an ultrahazardous condition for which elevation on fill will not reliably mitigate the risk
(National Academies of Science, Engineering, and Medicine 1996).
Urban Flooding
Urban flooding is not mapped by the State or FEMA, but is most likely to occur in highly developed areas
with high percentages of impervious coverage that contribute to high rates of runoff. Locations that have
undersized stormwater components or stormwater components that are prone to becoming clogged or
failing often experience stormwater flooding.
Urban flooding is traditionally often noteworthy when it occurs outside of the Special Flood Hazard Area,
where flooding is commonly anticipated. Like urban flooding, sheet flow is traditionally identified outside
of the FEMA defined Special Flood Hazard Area. The sheet flow hazard is represented by the zone
designation AO on the FIRM (FEMA 2020).
Repetitive loss areas within the City are subject to ponding against canal embankments. The potential
depth of flooding may vary depending on the location along the embankment from 1-foot to multiple feet.
Velocities would be minimal, but the warning time would likely be enough to protect property. The
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increased warning time would be due to the time it would take to see water starting to pond back from the
embankment to the structure which would hopefully allow time to get materials to adequately protect.
Areas within the City that area not mapped but have flooded in the past include areas along the mountain
to urban transition and older areas of the City with limited or no stormwater infrastructure. Flooding
sources in these areas would be from high intensity storm events that lead to flash flooding in the area
with high velocities and limited warning time.
Dam and Levee Failure Flooding
The Army Corps of Engineers and the Soil Conservation Service have built a number of flood retarding
structures on rivers, creeks, washes, and other flood-prone areas in Phoenix. The Flood Control District of
Maricopa County maintains and operates these structures. A failure of one of these structures, while
extremely unlikely, could result in a level of flooding that greatly exceeds the flood threat that existed prior
to construction.
Dams that directly impact the City are provided within Table 4-3. Data was captured from the U.S. Army
Corps of Engineers National Inventory of Dams and the Flood Control District of Maricopa County ALERT
web map.
Table 4-3. Dams Protecting the City of Phoenix
Name
Owner
Height (ft)
Cave Buttes Dam
Flood Control District of Maricopa County
118
Dreamy Draw Dam
Flood Control District of Maricopa County
42
Reach 11 Detention Dikes 1 through 4
Bureau of Reclamation
40
Rio Salado Town Lake (Tempe Town Lake)
City of Tempe
40
Guadalupe Flood Retarding Structure
Flood Control District of Maricopa County
37
Dam 2A
City of Phoenix
22.5
Dam 2B
City of Phoenix
22
North Mountain Flood Detention 3 (Dam 3)
City of Phoenix
30
Dam 4 (Little Dreamy Draw Dam)
City of Phoenix
21
Detention Basin 7 (Dam 7)
City of Phoenix
29
East Park Dam
City of Phoenix
24.8
West Park Dam
City of Phoenix
30
Dam 99
City of Phoenix
24.3
Papago Park and Phoenix Zoo Dams 1 to 8
City of Phoenix
Various
Roosevelt Dam
Salt River Project
357
Horse Mesa Dam
Salt River Project
304
Mormon Flat Dam
Salt River Project
224
Stewart Mountain Dam
Salt River Project
210
Horseshoe Dam
Salt River Project
202
Bartlett Dam
Salt River Project
309
Granite Reef Diversion Dam
Salt River Project
29
Source: (USACE 2025) & (FCDMC 2025)
Figure 4-5 and Figure 4-6 display emergency spillway flood hazard areas in Maricopa County. Figure 4-7
and Figure 4-8 display dam failure hazard areas in Maricopa County.
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Figure 4-5 Maricopa County Emergency Spillway Flood Hazard Map 1A
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Figure 4-6 Maricopa County Emergency Spillway Flood Hazard Map 1B
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Figure 4-7 Maricopa County Potential Dam Failure Flood Hazard Map 2A
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Figure 4-8 Maricopa County Potential Dam Failure Flood Hazard Map 2B
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Levees that are designed to reduce the risk of flooding posed by the 1-percent-annual chance flood may
be accredited by FEMA. An accredited levee system is a system that FEMA has determined to meet the
design, data, and documentation requirements of 44 CFR 65.10 and therefore can be shown on a FIRM as
providing a base chance or greater level of flood hazard reduction. This determination is based on a
submittal, by or on behalf of a community, which includes 44 CFR 65.10 – compliant data and
documentation, certified by a registered Professional Engineer. The area landward of an accredited levee
system is shown on the FIRM as a moderate-risk area, labeled Zone X (shaded), except for areas of interior
drainage flooding, such as ponding areas, which will be shown as high-risk areas, SFHAs. Flood insurance
is not mandatory in Zone X (shaded) areas, but it is mandatory in SFHAs. FEMA strongly encourages flood
insurance for all structures in floodplains and especially in areas landward of levees. FEMA accreditation
of a levee does not guarantee that it will always protect nearby properties from flooding; therefore, FIRMs
carry a notice that overtopping or failure of levees is possible and that flood insurance protection and
adherence to evacuation procedures are strongly recommended (FEMA 2020).
The City of Phoenix contains levee failure hazard areas associated with Skunk Creek to the north, New
River to the west, and the Salt River to the east. Table 4-4 describes the 14 levee systems located within
the City of Phoenix. There are an additional 45 levees in the greater Phoenix metro area that could directly
or indirectly impact the City in the event of failure.
Table 4-4. Levee Systems in the City of Phoenix
Name
Length
People
Protected
Buildings
Protected
Property Value
Protected
Critical
Structures
Protected
Agua Fria Reach 1A West
1 mile
183
18
$1 million
0
Camelback Ranch Levee
North (CBRLN)
1.3 miles
505
406
$120 million
1
Camelback Ranch South
0.5 miles
2,286
883
$150 million
0
Maricopa County Levee 21
4.6 miles
40,261
3,024
$4 billion
0
Maricopa County Levee 49
0.8 miles
7,036
2,369
$880 million
2
Maricopa County Levee 5
1.8 miles
592
7
$180 million
0
Maricopa County Levee 63
1.1 miles
2,892
189
$710 million
1
Maricopa County Levee 79
0.3 miles
0
0
0
0
Maricopa County Levee 80
4.3 miles
51
13
$4 million
1
Maricopa County Levee 85
1.7 miles
7,122
2,944
$1 billion
5
Scatter Wash North
0.8 miles
557
198
$88 million
1
Scatter Wash South
0.7 miles
5,241
1,739
$830 million
3
Skunk Creek 1
1.9 miles
2,577
636
$80 million
0
Skunk Creek 2
1.1 miles
279
102
$24 million
0
Source: (USACE 2025)
Figure 4-9 display potential levee failure flood hazard maps for Maricopa County.
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Figure 4-9 Maricopa County Potential Levee Failure Flood Hazard Map 5B
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4.11.3
Extent
The severity of a flood depends not only on the amount of water that accumulates in a period of time, but
also on the land's ability to manage this water. The size of rivers and streams in an area and infiltration
rates are significant factors. When it rains, soil acts as a sponge. When the land is saturated or overly dry,
infiltration rates decrease and any more water that accumulates must flow as runoff (Harris 2001).
The frequency and severity of flooding are measured using a discharge probability, which is the probability
that a certain river discharge (flow) level will be equaled or exceeded in a given year. Flood studies use
historical records to determine the probability of occurrence for the different discharge levels. The flood
frequency equals 100 divided by the discharge probability. For example, the 100-year discharge has a 1-
percent chance of being equaled or exceeded in any given year. The “annual flood” is the greatest flood
event expected to occur in a typical year. These measurements reflect statistical averages only; it is
possible for two or more floods with a 100-year or higher recurrence interval to occur in a short time period.
The same flood can have different recurrence intervals at different points on a river.
The extent of flooding associated with a 1-percent annual probability of occurrence (the base flood or 100-
year flood) is used by the NFIP as the standard for floodplain management and to determine the need for
flood insurance, as well as the regulatory flood boundary by many agencies. Also referred to as the Special
Flood Hazard Area (SFHA), this boundary is a convenient tool for assessing vulnerability and risk in flood-
prone communities. Many communities have maps that show the extent and likely depth of flooding for
the base flood. Corresponding water-surface elevations describe the water elevation resulting from a given
discharge level, which is one of the most important factors used in estimating flood damage. A structure
located within a SFHA shown on an NFIP map has a 26-percent chance of suffering flood damage during
the term of a 30-year mortgage.
The term “500-year flood” is the flood that has a 0.2-percent chance of being equaled or exceeded each
year. The 500-year flood could occur more than once in a relatively short period of time. Statistically, the
0.2-percent (500-year) flood has a 6-percent chance of occurring during a 30-year period of time, the length
of many mortgages. The 500-year floodplain is referred to as Zone X500 for insurance purposes on FIRMs.
Base flood elevations or depths are not shown within this zone, and insurance purchase is not required in
this zone (FEMA 2022).
While most dams and levees have storage volumes small enough that failures would have little or no
consequences, dams and levees with large storage amounts could cause significant flooding downstream.
Measuring Intensity
Riverine Flooding
In the case of riverine flood hazard, once a river reaches flood stage, the flood extent or severity categories
used by the NWS include minor flooding, moderate flooding, and major flooding. Each category has a
definition based on property damage and public threat:
•
Minor Flooding - minimal or no property damage, but possibly some public threat or inconvenience.
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•
Moderate Flooding - some inundation of structures and roads near streams. Some evacuations of
people and/or transfer of property to higher elevations are necessary.
•
Major Flooding - extensive inundation of structures and roads. Significant evacuations of people
and/or transfer of property to higher elevations (NOAA 2021).
Alluvial Fan Flooding
Alluvial fan flooding intensity can be defined by flooding frequency, flood depths, size of the alluvial fan,
volume of sediment moved, and designation of active and inactive areas. According to FEMA, the term
active refers to that portion of an alluvial fan where deposition, erosion, and unstable flow paths are
possible. If flooding and deposition have occurred on a part of an alluvial fan in the past 100 years, that
part of the fan can be considered to be active and at higher risk than inactive areas that have not seen
flooding or deposition in recent times (FEMA 2016).
Urban Flooding
Currently, there is no measurement used to further define the frequency and severity of stormwater/urban
flooding.
Dam and Levee Failure Flooding
A single dam failure event can result in catastrophic losses depending on the dam's location, size, storage
capacity, and the downstream population and infrastructure (Arizona Department of Emergency and
Military Affairs 2023).
The 2021 Maricopa County Multi-Jurisdictional Hazard Mitigation Plan estimates the magnitude of an
emergency spillway flow and dam failure to be critical. An event could result in (Maricopa County 2021):
•
Moderate property damages (greater than 25% and less than 50% of critical and non-critical
facilities and infrastructure).
•
Injuries or illnesses result in permanent disability and at least one death.
•
Shut down of critical facilities for more than 1 week and less than 1 month.
The duration of an emergency spillway flow and dam failure is projected to be less than 1 week (Maricopa
County 2021).
The extent or magnitude of a dam failure event can be measured in terms of the classification of the dam.
The state classifies hazard potential for each state-regulated dam using downstream hazard and dam
safety ratings.
Table 4-5 and Table 4-6 summarize the hazard classes and dam safety ratings used for Arizona-regulated
dams. Federally owned dams not regulated by the state use similar hazard classes and are all high-hazard
dams (Arizona Department of Emergency and Military Affairs 2023).
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Table 4-5. Downstream Hazard Classes for State Regulated Dams
Hazard Potential
Classification
Loss of Human Life
Economic, Environmental,
Lifeline Losses
Emergency Action Plan
Required?
Very Low
Not Likely
Limited to Owner or 100-
year floodplain
No
Low
Not Likely
Low and generally limited
to Owner
No
Significant
Not Likely
Yes
Yes
High
Likely
Yes (not necessary for
this classification)
Yes
Source: (Arizona Department of Emergency and Military Affairs 2023)
Note:
The hazard potential classification is an assessment of the consequences of failure, but not an evaluation of the probability
of failure.
Table 4-6. State Regulatory Dam Safety Ratings
Safety Rating
Definition
Safe
The dam has sufficient structural integrity and flood routing capacity to make failure
of the dam unlikely
Safety Deficiency
One or more conditions exist at the dam that impair or adversely affect the safe
operation of the dam.
Unsafe
The safety deficiencies in a dam or spillway could result in failure of the dam with
subsequent loss of human life or significant property damage.
Source: (Arizona Department of Emergency and Military Affairs 2023)
The magnitude and extent of a dam failure are estimated by analyzing and mapping the flood inundation
limits resulting from a projected failure event. State-regulated significant or high-hazard dams are required
to develop an Emergency Action Plan (EAP). Significant and high-hazard federal dams within Arizona
typically have EAPs with failure inundation limits (Arizona Department of Emergency and Military Affairs
2023).
Levee failures result in an uncontrolled release of water to the leveed areas, with potentially catastrophic
impacts. Failures may be attributed to a variety of modes and causes. The three most common are: 1)
foundation leakage and piping, 2) overtopping, and 3) embankment erosion (Arizona Department of
Emergency and Military Affairs 2023) .
The Levee Safety Action Classification (LSAC) is one of the many tools the USACE uses to better inform
stakeholders and residents of the residual risk in their communities. The LSAC is neither a levee rating or
grade, it is a classification system designed to consider the probability of the levees being loaded
(hazard), existing condition of the levee, the current and future maintenance of the levee
(performance), and the consequences if a levee were to fail or be overwhelmed. A levee that reduces risk
for a dense population will receive a different classification from an equally constructed levee with a
smaller population because the consequences associated with failure are greater (USACE n.d.).
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Table 4-7. Levee Safety Action Classification (LSAC) Table
Risk
Actions for Levee Systems and Leveed Areas in this Class
Risk Characteristics of
this Class
Very High (1)
Based on risk drivers, take immediate action to implement
interim risk reduction measures. Increase frequency of levee
monitoring, communicate risk characteristics to the
community within an expedited timeframe; verify emergency
plans and flood inundation maps are current; ensure
community is aware of flood warning systems and evacuation
procedures; and recommend purchase of flood insurance.
Support risk reduction actions as very high priority.
Likelihood of inundation due to
breach and/or system
component malfunction in
combination with loss of life,
economic, or environmental
consequences results in very
high risk.
High (2)
Based on risk drivers, implement interim risk reduction
measures. Increase frequency of levee monitoring;
communicate risk characteristics to the community within an
expedited timeframe; verify emergency plans and flood
inundation maps are current; ensure community is aware of
flood warning and evacuation procedures; and recommend
purchase of flood insurance. Support risk reduction actions as
high priority
Likelihood of inundation due to
breach and/or system
component malfunction in
combination with loss of life,
economic, or environmental
consequences results in high
risk
Moderate (3)
Based on risk drivers, implement interim risk reduction
measures as appropriate. Verify risk information is current and
implement routine monitoring program; assure O&M is up to
date; communicate risk characteristics to the community in a
timely manner; verify emergency plans and flood inundation
maps are current; ensure community is aware of flood
warning and evacuation procedures; and, recommend
purchase of flood insurance. Support risk reduction actions as
a priority
Likelihood of inundation due to
breach and/or system
component malfunction in
combination with loss of life,
economic, or environmental
consequences results in
moderate risk.
Low (4)
Verify risk information is current and implement routine
monitoring program and interim risk reduction measures if
appropriate; assure O&M is up to date; communicate risk
characteristics to the community as appropriate; verify
emergency plans and flood inundation maps are current;
ensure community is aware of flood warning and evacuation
procedures; and, recommend purchase of flood insurance.
Support risk reduction actions to further reduce risk to as low
as practicable
Likelihood of inundation due to
breach and/or system
component malfunction in
combination with loss of life,
economic, or environmental
consequences results in low
risk
Very Low (5)
Continue to implement routine levee monitoring program,
including operation and maintenance, inspections, and
monitoring of risk. Communicate risk characteristics to the
community as appropriate; verify emergency plans and flood
inundation maps are current; ensure community is aware of
flood warning and evacuation procedures; and recommend
purchase of flood insurance.
Likelihood of inundation due to
breach and/or system
component malfunction in
combination with loss of life,
economic, or environmental
consequences results in very
low risk.
No Verdict
Not enough information is available to assign an LSAC
-
Source: (USACE 2017)
Warning Time
Most floods are preceded by a warning period that allows emergency managers to communicate the need
to prepare for the event. A flood may last from minutes to days (O'Connor, Grant and Costa 2002).
Warnings issued through official sources, such as the National Weather Service (NWS) and the Storm
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Prediction Center, provide the most reliable and timely preparedness information, but the exact flood
location and depth depends on the amount, duration, and location of rainfall. For Arizona, those times will
vary depending on the type of precipitation event and the size of the watercourse and tributary watershed
(Arizona Department of Emergency and Military Affairs 2023).
Typical monsoon thunderstorms develop rapidly and are relatively small in areal extent with short duration,
high-intensity bursts of rainfall that result in swiftly moving flash floods. The full warning times for
monsoon events are usually less than a couple of hours, and flood peak arrival times can be measured in
minutes for small watersheds. Many of the fatalities associated with flood events within the state are due
to thunderstorms that caused flash floods that caught people unaware (Arizona Department of Emergency
and Military Affairs 2023).
Tropical storms moving into Arizona typically have more advanced meteorological notice and tracking.
Rainfall areal extents and durations are typically larger and longer than monsoon storms, but intensities
can still generate fairly rapid peak flows. Full warning times for tropical storm remnants are usually greater
than six hours, with flood peak arrival times in a couple of hours, depending on the watercourse and
watershed size (Arizona Department of Emergency and Military Affairs 2023).
General winter storms have a longer duration, low-intensity rainfall that covers large areas of the state and
produces runoff that gradually accumulates to peak flood stages. Winter storms moving into Arizona
typically have more advanced meteorological notice and tracking. Full warning times generally exceed 12
hours, with flood peak arrival times in several hours (Arizona Department of Emergency and Military Affairs
2023).
The NWS uses the following advisories, watch, and warnings when flooding conditions are anticipated
(NWS 2025):
•
Flood Advisory: Issued when flooding is forecast to occur, generally within the next 6 hours, but is
not expected to substantially threaten life and property.
•
Flash Flood Warning: Issued when flash flooding is imminent, generally within the next 6 hours.
This is usually issued based on observed heavy rainfall (measured or radar estimated) for
dangerous small stream or urban flooding but may also be issued for significant dam or levee
failures that have occurred or are imminent.
•
Areal Flood Warning: Issued when widespread general flooding is forecast to occur throughout an
identifiable geographic area.
•
Flood Warning for River Forecast Point: Issued when a river gauge is forecast to exceed a
predetermined flood stage.
Once initiated, a levee failure can occur very rapidly, with a sudden, uncontrolled release of the stored or
impounded water. Warning times for populations located in the leveed areas are dependent upon the speed
of the flood-wave and distance from the breach. In most cases for Arizona, this is usually measured in tens
of minutes. Extreme weather events with a potential to trigger or cause a failure will also have at least
hours of warning if not a few days (Arizona Department of Emergency and Military Affairs 2023).
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Worst Case Scenario
A worst case scenario for flooding in the City of Phoenix would be a poorly forecast, slow moving monsoon
style rainfall events that lasts for numerous hours, preceded by rainfall events in the region that resulted in
fully saturated soils and bring rivers and streams to bankfull stage (the water level where a waterbody
reaches the tops of its banks. Any additional water volume will result in overflow). Such an event would
result in near immediate riverine, alluvial fan, and urban flooding and potential for dam and levee failures.
4.11.4
Previous Occurrences
The following sections provide a review of previous flood occurrences in the City of Phoenix.
4.11.4.1
Federal Declarations
Review of presidential disaster declarations helps establish the probability of reoccurrence for hazards and
identify targets for risk reduction. Disaster declarations are made at the county level. Table 4-8 summarizes
the federal disaster declarations involving flood that included Maricopa County since 1954. Out of 26 total
presidential declarations, 12 involved flooding.
Table 4-8. FEMA Flood Disaster Declarations
Disaster Number
Incident Period
Declaration Date
Description
DR-217-AZ
April 30, 1966
April 30, 1966
Arizona Flooding
DR-294-AZ
September 22, 1970
September 22, 1970
Arizona Heavy Rains, Flash Floods
DR-343-AZ
July 3, 1972
July 3, 1972
Arizona Severe Storms, Flooding
DR-551-AZ
March 4, 1978
March 4, 1978
Arizona Severe Storms, Flooding
DR-570-AZ
December 21, 1978
December 21, 1978
Arizona Severe Storms, Flooding
DR-614-AZ
February 19, 1980
February 19, 1980
Arizona Severe Storms, Flooding
DR-884-AZ
July 8 – September 14, 1990
December 6, 1990
Arizona Flooding, Severe Storm
DR-977-AZ
January 5 – March 6, 1993
January 19, 1993
Arizona Severe Storms,
Tornadoes, Flooding
DR-1304-AZ
September 14 - 23, 1999
October 15, 1999
Severe Storms, High Winds and
Flooding in Arizona
DR-1347-AZ
October 21 – November 8, 2000
October 27, 2000
Severe Storms and Flooding in
Arizona
DR-1586-AZ
February 10-15, 2005
April 14, 2005
Arizona Severe Storms and
Flooding
DR-4203-AZ
September 7-9, 2014
November 5, 2014
Arizona Severe Storms and
Flooding
Source: (FEMA 2025)
4.11.4.2
Summary of Significant Events
The 2021 Maricopa County Multi-Jurisdictional Hazard Mitigation Plan identified the following significant
flooding events in Maricopa County. These events had direct and indirect impacts on the City of Phoenix
(Maricopa County 2021):
•
In March 1978, a general winter storm centered over the mountains north and east of Phoenix, 35
miles north at Rock Springs. Extrapolation of intensity-probability data for one measurement of
5.73 inches of precipitation in a 24-hour period equates to a 400-year storm. The main source of
flooding was due to the Verde River runoff volume exceeding reservoir storage capacity above
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Bartlett Dam. Flooding also occurred along irrigation canals on the north side of the Phoenix metro
area, and along tributaries of the Gila River and Queen Creek. There was one death countywide and
$37 million in total damages. The event resulted in Presidential Disaster Declaration 550-DR.
•
In December 1978, a second major storm for the year hit hard with total precipitation that ranged
from less than 1 inch in the northeastern and far southwestern portions of Arizona to nearly 10
inches in the Mazatzal Mountains northeast of Phoenix. A large area of the central mountains
received over 5 inches. The main stems of the Gila, Salt, Verde, Agua Fria, Bill Williams, and Little
Colorado Rivers, as well as a number of major tributaries, experienced especially large discharges.
There were 4 deaths, $16.3 million-public and $5 million in agriculture losses estimated for
Maricopa County. The event resulted in Presidential Disaster Declaration 570-DR.
•
In February 1980, severe flooding in central Arizona set record discharges (later broken in 1993) in
the Phoenix metro area on the Salt, Verde, Agua Fria and Gila Rivers, as well as on Oak Creek in
north central Arizona. The Phoenix metro area was nearly cut in half with only two bridges
remaining open over the Salt River. It took hours for people to move between Phoenix and the east
valley using either the Mill Avenue or Central Avenue bridges. Even the Interstate 10 bridge was
closed for fear that it had been damaged. Precipitation during this period at Crown King in the
Bradshaw Mountains was 16.63 inches. Three people died statewide, and damages were
estimated at $63,700,000 for the Phoenix Metro Area. The event resulted in Presidential Disaster
Declaration 614-DR.
•
In January and February 1993, flooding damage occurred from winter storms associated with the
El Nino phenomenon. These storms flooded watersheds throughout Arizona by dumping excessive
rainfall amounts that saturated soils and increased runoff. Warm temperature snowmelt
exacerbated the situation over large areas. Erosion caused tremendous damage and some
communities along normally dry washes were devastated. Stream flow velocities and runoff
volumes exceeded historic highs. Many flood prevention channels and retention reservoirs were
filled to capacity and water was either diverted to the emergency spillways or the reservoirs were
breached, causing extensive damage in some cases (e.g., Painted Rock Reservoir spillway). The
new Mill Avenue Bridge and a large landfill in Mesa were washed away by the raging Salt River. The
Gillespie Dam west of Phoenix was damaged as high water spread throughout low-lying areas.
Many roads were closed, and motorists were stranded by flooded dips and washes. Phoenix alone
sustained at least $4.2 million in damages from this prolonged period of heavy rains. County-wide,
$38 million in property and agricultural losses were estimated. The event resulted in Presidential
Disaster Declaration 977-DR.
•
In late July – early August 2005, one of the heaviest rainfall events of the 2005 season struck the
greater Phoenix metropolitan. Almost three inches of rain fell at many locations in the metro,
causing roofs to collapse and streets to flood quickly. Up to 120 residents at the Crystal Creek
Apartments in Phoenix were evacuated after 83 apartment units were damaged by flood waters.
Additional roof damage was reported at the Scottsdale Community College, and Osco Drug store
in Mesa, and a Fry’s grocery store in Tempe. In the Wickenburg area, very heavy rainfall caused
flooding of low spots and washes. The peak flow in Hartman Wash was reported as 1,200 cfs.
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Major damage occurred at Bear Cat Manufacturing where a large robotic welding building was
destroyed by the flood. Losses were estimated at over $4 million.
•
In September 2014, heavy rainfall caused by the remnants of Hurricane Norbert resulted in
extensive flooding throughout the state and especially in La Paz, Maricopa, and Pinal Counties. The
Phoenix area experienced its wettest day in history, surpassing a record set in 1939. Preliminary
damages assessments exceeded $18 million. Among other impacts, major sections of freeways
were closed, canals and flood control systems were overwhelmed, and two individuals perished in
separate flash flood incidents. Several valley locations received rainfall that exceeded 500-year
storm estimates. State search and rescue teams spent considerable resources performing
numerous rescues of stranded drivers and residents, in addition to services provided during
flooding from two other hurricane remnants (Hurricane Lowell and Hurricane Odile), all of which
impacted Arizona within a two-month period. The state received a presidential disaster declaration
(DR-4203) for Maricopa and La Paz Counties in November 2014.
4.11.4.3
Recent Events
Table 4-9 displays recent flooding events that have impacted Maricopa County since January 1, 2021. For
a history of flooding events prior to January 2021, refer to the 2021 Maricopa County Multi-Jurisdictional
Hazard Mitigation Plan.
Table 4-9. Recent Flood Hazard Events
Date(s) of
Event
Declaration
Number
County
Included
Description
July 3-4,
2021
N/A
N/A
Strong thunderstorms developed in the afternoon over the high terrain
of central and southern Arizona before spreading to the lower deserts
through the evening, with new development driven mostly by strong
outflow boundaries. The primary outflow boundary moved southwest
with widespread 30-40 mph wind gusts observed across south-central
Arizona and a few stronger gusts, including a 59-mph gust in southern
Gila County. The winds were strong enough to cause hundreds of power
outages in the Phoenix metro area and generate dense blowing dust
over the open deserts in Pinal and western Maricopa counties. With
above normal moisture levels, storms also produced localized flash
flooding mostly in foothill/high terrain areas, including flash flooding
enhanced by recent burn scars.
July 10,
2021
N/A
N/A
Thunderstorms developed along the Mogollon Rim during the early part
of the afternoon on the 9th and propagated westward into the lower
deserts. The severe thunderstorms led to damaging winds gusts
upwards of 60-65 mph across southeast portions of the Phoenix metro.
The severe winds ahead of the thunderstorms also produced a dust
storm that led to widespread reports of dense blowing dust across
central and southeastern Phoenix and as far south as Casa Grande. A
few isolated instances of flash flooding occurred as well, including the
recent Telegraph burn scar where over 0.75 of rain fell. There were
numerous reports of damage across eastern parts of the Valley,
including numerous power poles and large trees down. No injuries were
reported with these thunderstorms.
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Date(s) of
Event
Declaration
Number
County
Included
Description
July 14-15,
2021
N/A
N/A
A shortwave trough moving across the state promoted the development
of thunderstorms capable of producing strong winds and locally heavy
rainfall, which led to some reports of flash flooding.
July 21-23,
2021
N/A
N/A
With enhanced easterlies on the south end of the monsoon high and
embedded weak perturbation waves rolling west across southern
Arizona, scattered strong to severe thunderstorms developed in a moist
unstable environment throughout the afternoon and evening on the
21st. Most storms in the afternoon developed across southwest
Arizona, between Phoenix and the Colorado River, with sporadic storm
motions driven by outflows and cell mergers. In the evening of the 21st,
new showers and thunderstorms developed and spread through south-
central Arizona, including in the Phoenix metro area. With high moisture
content and strong forcing, thunderstorms produced very heavy rain
with rainfall rates around 1.5-2.0 inches per hour with briefly higher
rates for short periods.
Strong to severe thunderstorms developed in an unstable atmosphere
in the afternoon of the 22nd. Storms initially developed over the high
terrain of northern and eastern Arizona as well as near the Table Top
mesa area south of Phoenix. The thunderstorms in the Phoenix metro
area produced damaging winds that led to numerous downed trees,
downed power poles, and other property damage. The storms were also
nearly stationary, under weak steering flow, and produced very heavy
rainfall with rain rates around 1.5-2.0 inches per hour and briefly higher
in the strongest storms. This led to considerable flash flooding around
Phoenix with several road closure and significant flow in major washes.
Even after the strongest storms in Phoenix subsided in the late evening
of the 22nd, areas of moderate to heavy rain continued from northeast
to southwest through the night and through mid-afternoon on the 23rd.
The continued rain through the 23rd was aided by a strengthening
diffluent flow regime between the monsoon high to the north and a
retrograding upper low moving west through New Mexico. Additional
significant flash flooding was observed on the 23rd, mostly in the
foothills north of the Phoenix metro, with many road closures, flowing
washes and creeks, and some water rescues.
July 25,
2021
N/A
N/A
A retrograding upper level low combined with anomalously high
moisture levels led to showers and isolated thunderstorms producing
heavy rainfall and numerous instances of considerable flash flooding
across south-central Arizona on the 25th. The places that saw the
heaviest rainfall amounts were areas that experienced heavy showers
training over the same locations. Western portions of the Phoenix metro
saw training showers with heavy rainfall occur, leading to widespread
amounts of 1.5-2.5 inches with locally higher amounts of 3+. As a result,
there were numerous reports of flash flooding, including multiple water
rescues and numerous road closures due to flooding. Heavy rainfall
also fell over multiple burn scars, leading to several instances of burn
scar flash flooding. One of the burn scars that saw heavy rainfall was
the Bush fire burn scar, which led to enhanced runoff and a rapid rise on
Sycamore Creek. Several people were rescued after getting stuck in the
increased flow in Sycamore Creek. No injuries were reported.
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Date(s) of
Event
Declaration
Number
County
Included
Description
August 10,
2021
N/A
N/A
In a moisture rich environment, slow-moving thunderstorms in the
morning of the 10th produced very heavy rainfall, with rain rates
upwards of 2 to 2.5 inches per hour, leading to localized flash flooding
in parts of Maricopa and Pinal counties.
August 11-
12, 2021
N/A
N/A
An upper-level low sitting over central Arizona on the 11th and 12th led
to the development of multiple rounds of showers and thunderstorms
across the region. Anomalously high moisture in the region allowed this
activity to produce heavy rainfall which led to multiple instances of flash
flooding across south-central and southwest Arizona. Some of these
thunderstorms became strong to severe and produced strong wind
gusts that led to several reports of damage. No injuries were reported.
August 13-
14, 2021
N/A
N/A
A classic bow echo developed along the Mogollon Rim in central
Arizona on the 13th and merged with thunderstorm clusters that
developed in south-central Arizona to form one southwestward-moving
system that progressed all the way to the town of Yuma in far
southwest Arizona on the 14th. The system produced widespread
strong winds with localized damaging winds from individual
microbursts across the region. The strong winds also generated dense
blowing dust in southwest Arizona. In addition to the wind, storms were
producing average rain rates of 1 to 2 inches per hour with briefly higher
rates in the strongest cells. This led to flash flooding in multiple areas.
August 16-
17, 2021
N/A
N/A
A shortwave trough rotating through the region led to steepening lapse
rates and increasingly unstable conditions across central Arizona on the
16th. With abundant moisture, the environment was favorable for the
development of strong to severe thunderstorms. Thunderstorms initially
developed over the high terrain of eastern Arizona before racing toward
the west/southwest into the lower deserts of south-central Arizona as a
line of strong to severe thunderstorms. The main impacts associated
with these thunderstorms occurred as they moved into the Phoenix
metro, producing widespread damaging wind gusts. Multiple
observations recorded wind gusts in excess of 60 mph with a few
approaching 80 mph. Recently implemented damage threat categories
for Severe Thunderstorm Warnings were put to the test with one
destructive Severe Thunderstorm Warning being issued for 80 mph
wind gusts for much of Phoenix. There were numerous reports of
downed trees across the Valley as a result of the severe wind gusts. The
strong winds also led to several reports of dense blowing dust in dust
prone areas. Additionally, thunderstorms produced locally heavy rainfall
that led to several instances of flash flooding. No injuries were reported.
August 18,
2021
N/A
N/A
Moderate to high instability and high moisture content supported
scattered strong thunderstorms. Storms favored the foothills and
mountainous areas of Maricopa and Gila counties. Most storms were
producing at least 1 to 2 inch per hour rain rates, with several storms
producing 2-to-3-inch rates and at times higher. Back-building and
training of storms over the same areas resulted in significant to
catastrophic flash flooding. A few burn scars experienced flash flooding,
including the recent Telegraph burn area which had catastrophic
flooding of the Russell Gulch drainage. There were also 2 fatalities on
this day with off-roaders recreating near Camp Creek in northeast
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Date(s) of
Event
Declaration
Number
County
Included
Description
Maricopa County. The strong to severe storms also produced damaging
winds from microbursts and small hail over lower desert locations.
September
1, 2021
N/A
N/A
Thunderstorms produced locally heavy rainfall across parts of
southwest and south-central Arizona during the early morning hours on
the 1st, resulting in some flash flooding. No damage or injuries were
reported.
September
18, 2021
N/A
N/A
A shortwave trough moving through the region combined with a moist,
unstable atmosphere promoted the development of showers and
thunderstorms across south-central Arizona going into the afternoon on
the 18th. Adequate shear allowed for some thunderstorms to become
strong to severe, leading to multiple reports of damaging winds and
dense blowing dust. Additionally, thunderstorms were capable of
producing locally heavy rainfall leading to isolated flash flooding. No
injuries were reported.
October 5,
2021
N/A
N/A
As the region transitioned out of the monsoon, parameters were
sufficient for supercell thunderstorm development and a few supercells
did develop amongst isolated to scattered storms in the afternoon
across South-central Arizona. Damaging wind, hail, and isolated flash
flooding was also observed through the afternoon.
December
24, 2021
N/A
N/A
A moderate to strong atmospheric river aligned over South-central
Arizona and led to widespread light to moderate rain across the region.
Rain began falling the night of the 23rd and lasted through the evening
of the 24th. The Phoenix area measured 1-2 inches and most foothill
and mountainous areas measured 2-3 inches, with a few localized
spots measuring 3-4 inches. The high rainfall amounts led to minor
urban flooding and elevated flows in typically dry washes as well as in
several major creeks and rivers.
June 24-
25, 2022
N/A
N/A
Outflow boundaries originating from distant thunderstorms converged
on the valley floor during the evening hours. This resulted in the
development of a strong thunderstorm over Chandler. Other weaker
thunderstorms developed across the valley as well from the resulting
outflow boundaries. A strong thunderstorm that developed near
Morristown caused downed powerlines, resulting in the closure of US-
60. No injuries were reported.
June 26,
2022
N/A
N/A
Widespread thunderstorm activity was observed across most of south-
central and southwest Arizona. Storms first developed across the
higher terrain north and east of Phoenix as well as across portions of
southern Maricopa County during the early afternoon hours. These
storms sent two outflow boundaries from opposing directions, which
then collided across the Phoenix metro, sparking the development of
additional storms over the Phoenix area. Another cluster of storms then
developed across portions of southwest Arizona during the late
afternoon into the early evening hours. No damages or injuries were
reported.
July 13,
2022
N/A
N/A
Thunderstorm activity first developed across southeast Arizona and
then were steered by the southeasterly flow into south-central Arizona.
Portions of the East Valley got particularly hit hard between Gilbert and
Mesa, where there were several reports of wind damage. No injuries
were reported.
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Date(s) of
Event
Declaration
Number
County
Included
Description
July 24,
2022
N/A
N/A
A moisture-rich environment was in place on the 24th. A weak
disturbance embedded in the flow aided in shower and thunderstorm
development to persist out of southeast Arizona and into central
portions of the state. Given the amount of moisture in the environment,
thunderstorms were able to produce locally heavy rainfall which led to
isolated flash flooding in southern Maricopa County.
July 25-26,
2022
N/A
N/A
Deep monsoonal moisture allowed for showers/thunderstorms to be
efficient rainfall producers leading to isolated flash flooding. A trained
spotter near Arcacia Drive and 186th Drive reported 0.50 of rain in 20
minutes. To the south, flash flooding was reported in Waterman Wash,
making roads impassable and leading to a water rescue. Additional
heavy rainfall in the evening resulted in more isolated flash flooding. No
injuries were reported.
July 28,
2022
N/A
N/A
The combination of near record moisture content, moderate to strong
instability, very slow steering flow and an upper-level disturbance
resulted in a very conducive environment for the generation of
thunderstorms producing very heavy rainfall activity across portions of
south-central and southwestern Arizona, resulting in flash flooding.
Activity first developed across the foothills and higher terrain of Eastern
Maricopa and Gila Counties during the late morning-early afternoon
hours. Another area of thunderstorms developed over northwestern
Arizona during the mid-late afternoon hours and move southward
towards La Paz County into the evening hours. One of the areas
severely hit by flash flooding was Apache Junction, AZ. Weekes Wash,
which runs through the town, went out of its banks, causing widespread
flooding impacts across the city. Flooding also took place from
drainage that occurred off the Goldfield and Superstitions Mountains.
July 30,
2022
N/A
N/A
Daytime heating combined with divergence aloft associated with an
easterly wave near the Arizona/New Mexico border promoted
thunderstorm initiation across southeast Arizona during the afternoon
of the 30th. Outflow boundaries generated from these thunderstorms
raced northwest toward south-central Arizona, resulting in a dust storm
in Pinal County where multiple instances of dense blowing dust less
than 1/4 mile were reported. New thunderstorm development occurred
along these boundaries with some thunderstorms becoming severe.
Numerous instances of damaging winds were reported across the
Phoenix area and down into northwest Pinal County, which included
multiple downed trees and power poles. A very moist environment
allowed for thunderstorms to become efficient heavy rainfall producers.
Rainfall amounts upwards of around 1.50 within an hour were reported
during the event. There were multiple reports of flash flooding across
northern parts of the Phoenix area, leading to several water rescues and
making some roads impassable. Flash flooding also led to water and
mud entering some apartments in north Phoenix causing extensive
water damage. No injuries were reported with this event.
July 31,
2022
N/A
N/A
An upper-level disturbance lingering over the area led to the
development of strong storms across portions of southern and central
Arizona during the afternoon hours. Outflow winds led to areas of
blowing dust with the more persistent storms leading to isolated flash
flooding.
4 | Step 4: Assess the Hazard
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August 4,
2022
N/A
N/A
A large thunderstorm complex developed and tracked into south-central
Arizona during the early morning hours on the 4th with widespread
heavy rainfall activity across the Phoenix area, leading to flash flooding.
The thunderstorm complex continued to track westward through
southwest Arizona and into the Lower Colorado River Valley through the
morning hours while at the same time weakening in the process.
August 10,
2022
N/A
N/A
Under an easterly wind flow, thunderstorm activity moved across
portions of south-central and southwestern Arizona during the late
afternoon and early evening hours. The strongest thunderstorm activity
was concentrated from western Maricopa County through most of La
Paz and Yuma Counties. Strong instability resulted in an environment
favorable for the development of strong to severe thunderstorms, which
led to instances of damaging wind gusts as well as flash flooding.
August 12,
2022
N/A
N/A
Classical monsoonal regime, with deep-layered east to southeast flow,
high instability along with abundant moisture resulted in an
environment favorable for thunderstorms. An upper-level disturbance
moving across Arizona, aided in increasing the areal coverage as well
as enhancing the thunderstorm activity.
August 14,
2022
N/A
N/A
Abundant moisture and instability provided a favorable environment for
strong to severe thunderstorms across south-central Arizona on the
14th. Daytime heating aided in thunderstorm development across the
high terrain north of Phoenix before sending outflows traveling toward
the south into the lower elevations. New thunderstorm development
occurred along these outflows into the Valley where they produced
damaging winds, dense blowing dust, and isolated flash flooding.
Additional thunderstorm development occurred across southwest
Arizona where better moisture allowed thunderstorms to be efficient
rainfall producers, leading to multiple reports of flash flooding. No
injuries were reported from this event.
August 17,
2022
N/A
N/A
Abundant moisture across south-central and southwest Arizona
allowed for convective development to become strong to severe.
Thunderstorms initiated over the high terrain of northern Arizona before
working toward the south into the lower deserts. Severe thunderstorms
produced damaging wind gusts upwards of 60-70 mph along with
several reports of flash flooding. No injuries were reported.
August 18,
2022
N/A
N/A
Favorable monsoonal conditions promoted the development of severe
thunderstorms across the region on the 18th. Abundant moisture and
instability were in place across south-central and southwest Arizona,
while increased easterly steering flow from an upper level low over
northern Mexico aided in thunderstorms propagating off the high
terrain. Strong to severe thunderstorms produced damaging winds from
downbursts. Thunderstorms initially developed along the Mogollon Rim
during the early afternoon hours before pushing into the lower deserts
of south-central and southwest Arizona through the evening. No injuries
were reported.
August 19-
20, 2022
N/A
N/A
Thunderstorms on the 19th initiated across southeast Arizona and
along the Mogollon Rim during the late morning/early afternoon hours
before pushing into the lower elevations of south-central Arizona. A
couple of upper-level features, which included an area of low pressure
over northern Sonora and a shortwave trough over the Great Basin,
4 | Step 4: Assess the Hazard
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Description
aided in ascent over the region in an environment characterized by high
instability and anomalously high moisture. Given the moisture in place,
thunderstorms were able to become efficient rainfall producers, leading
to multiple reports of flash flooding across the area. No injuries were
reported.
August 20,
2022
N/A
N/A
By the late afternoon and early evening hours on the 20th, new
thunderstorms initiated over the high terrain of northern Arizona. High
instability aided in maintaining strong to severe thunderstorms into the
Phoenix area as thunderstorms pushed toward the south and into the
lower deserts during the evening. Strong to severe downbursts were
associated with the strongest thunderstorms. Thunderstorms were
heavy rainfall producers, leading to several reports of flash flooding. No
injuries were reported.
August 21,
2022
N/A
N/A
Isolated showers and thunderstorms initially began across parts of
southern Gila County, along with eastern Maricopa County and
northeast Pinal County, producing locally heavy rainfall leading to
isolated flash flooding. By the late afternoon and early evening hours on
the 20th, new thunderstorms initiated over the high terrain of northern
Arizona. High instability aided in maintaining strong to severe
thunderstorms into the Phoenix area as thunderstorms pushed toward
the south and into the lower deserts during the evening. Strong to
severe downbursts were associated with the strongest thunderstorms.
Thunderstorms were heavy rainfall producers, leading to several reports
of flash flooding. No injuries were reported.
August 23-
24, 2022
N/A
N/A
A mid-level high pressure was situated across southern Nevada, with
the local area under a northeasterly flow regime. The moisture and
instability parameters were conducive to thunderstorm activity. As it is
typical in a northeasterly flow regime, thunderstorms first began to
develop along the Mogollon Rim early afternoon and then descended
into the lower elevations during the mid to late afternoon hours,
affecting the Greater Phoenix area and then tracking southwestward,
affecting southwestern Arizona through the early evening hours.
August 27,
2022
N/A
N/A
High pressure situated south of the International Border led to a
westerly flow aloft, which caused dry air advection. However, there was
still sufficient moisture and instability to result in the development of
strong thunderstorms across portions of south-central and southwest
Arizona. There were favorable conditions for some of these
thunderstorms to produce severe wind gusts.
September
2, 2022
N/A
N/A
Under a classic setup for storm motion from the Northern Arizona high
terrain to Southern Arizona lower deserts, a few multicell storm clusters
developed and progressed west-southwest through the lower deserts in
the afternoon and evening hours of the 2nd. Increased east-northeast
steering flow resulted in relatively high shear values for the monsoon
Moisture levels were also above normal which, in combination with the
strong updrafts, supported high rainfall rates (1.5-2 inches per hour
average). There were a few multicell clusters that moved through
Southern Arizona. One through the southeast parts of the greater
Phoenix area, another that developed in Yavapai County before
descending southwest along US-60 in Maricopa and La Paz Counties,
and a third that developed off the Kofa Wilderness terrain south of
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Quartzsite before being caught by the cluster descending along US-60.
Each cluster produced damaging winds, dense blowing dust, small to
severe hail, and localized flash flooding.
September
9-10, 2022
N/A
N/A
Broad southeast flow associated with the circulation of Tropical Storm
Kay, which was located just west of the Baja California Peninsula, set up
across Arizona. High moisture and instability helped enhance the
shower and thunderstorm activity.
September
11-12,
2022
N/A
N/A
The remnant mid-level circulation of what was Tropical Cyclone Kay
was located over southern California. This led to southerly flow across
Arizona, which helped increased moisture and instability. Strong to
severe thunderstorms developed across southeast Arizona, near the
Tucson area, during the late afternoon hours of the 11th and then
progressed northward towards the Phoenix metro during the evening
hours, resulting in widespread severe downburst winds and blowing
dust as well as isolated flash flooding. The Phoenix Sky Harbor Airport
reported a peak wind gust of 86 mph. Additional storms then developed
across western Maricopa County, extending into La Paz County, during
the early morning hours of the 12th with heavy rainfall leading to flash
flooding become the biggest threat.
September
21, 2022
N/A
N/A
High pressure across the southern Plains and low pressure across the
Great Basin led to a southerly flow across the region, advecting deep
moisture. The forcing from the aforementioned low pressure helped to
enhance the thunderstorm activity as it was moving from south to
north.
September
23, 2022
N/A
N/A
An abundance of moisture and moderate to high instability led to the
development of terrain and diurnally induced thunderstorm activity.
Thunderstorms first began to develop across portions of southwestern
Arizona during the early afternoon hours and thereafter, additional
storm development occurred across the higher terrain east of Phoenix.
Outflow from storms, particularly across the higher terrain east of
Phoenix led to the development of more storms across portions of the
Phoenix metro, particularly in the area between Chandler and Queen
Creek.
October 6,
2022
N/A
N/A
A slow-moving cutoff low was situated over southern Arizona, providing
forced ascent. Two rounds of convection occurred, with the first round
affecting portions of south-central Arizona during the very early morning
hours and the second round affecting far southwest Arizona during the
early to midafternoon hours. With the help of daytime heating boosting
instability values into the moderate to high side, the thunderstorm
activity affecting southwestern Arizona became intense with reports of
hail. Moisture content was also on the high side during the two rounds
of convection with precipitable water values near record values for early
October. This resulted in numerous reports of flash flooding, with the
first round of convection during the early morning hours generating
flash flooding along State Route 238, just to the northeast of Gila Bend,
and the second round of convection during the early to mid-afternoon
hours generating flash flooding across State Route 95, north of Yuma.
October
15-16,
2022
N/A
N/A
A slow-moving low-pressure system brought several rounds of showers
and thunderstorms across portions of south-central and southwestern
Arizona throughout the day on the 15th. Strong southerly flow out
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Description
ahead of the low-pressure system brought in highly anomalous
moisture content across the southern half of Arizona at near record
values for mid-October. Along with the highly anomalous moisture
values, moderate to high instability values were also present. The
combination of the highly anomalous moisture content, instability, and
shear along with the strong dynamic forcing to the east and north of the
low-pressure system was a recipe for these showers and
thunderstorms to produce flash flooding as well as severe wind gusts
and hail. The greatest flash flood impact occurred along portions of
western Maricopa County in the area from Buckeye to Tonopah. The
greatest damaging wind impact occurred in the Tonopah area, where
two rounds of severe thunderstorms, one hour apart, impacted causing
widespread power outages due to downed power poles, destroyed two
mobile homes, damaged dairy farm structures, and resulted livestock
losses. Severe hail was also reported with a storm that moved into the
Mesa to Scottsdale area during the overnight period.
March 2,
2023
N/A
N/A
A strong late season winter storm moved across the Desert Southwest
during the afternoon and evening on the 1st, lasting through the early
morning hours on the 2nd. Strong winds were observed out ahead of an
associated cold front with gusts in excess of 40 mph observed.
Moderate to locally heavy rains associated with the cold front were also
observed with most areas in and around the Phoenix metro observing
between 0.5 to 1. This rainfall was enough to result in some elevated
flows across northern Maricopa County near the Carefree and Cave
Creek areas. Behind the cold front, a very cold air mass was pulled
down into the region changing the rain to snow across areas mainly
above 2000 feet during the overnight hours of the 1st into the 2nd,
resulting in measurable snowfall accumulations.
March 4-
31, 2023
N/A
N/A
Anomalous snowfall across the high terrain of Arizona as well as lower
elevation rainfall led to greater than normal runoff into the Salt and
Verde watersheds. As a result of this, dam releases were conducted at
multiple locations in these watersheds, leading to heightened flows in
these rivers. Upstream releases led to additional releases from Granite
Reef Dam, which initially began to cause impacts on the 4th when
releases from the dam increased above 1,000 cfs. Granite Reef Dam
releases continued to increase going through the month of March and
at one point during the month was releasing nearly 40,000 cfs. Releases
from this dam led to downstream flow in the normally dry Salt River,
which runs through the Phoenix metro. The anomalous runoff into the
Salt and Verde watersheds and the resultant dam releases led to
numerous impacts along the Salt, Verde, and Gila Rivers, including
multiple unbridged river crossings being flooded, multiple water
rescues, and one recreational fatality. Flow in the Salt River continued
downstream into the Gila River, causing more impacts along the way
down to Painted Rock Dam. Releases continued through the remainder
of the month and into April, resulting in prolonged impacts.
March 11,
2023
N/A
N/A
A robust moisture plume from an atmospheric river event moved
across the region. The available moisture in combination with
orographic lift resulted in the development of a couple of thunderstorms
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across the foothills to the north and east of Phoenix during the
afternoon hours.
March 15-
16, 2023
N/A
N/A
An area of low pressure moving across the western states resulted in
waves of rainfall across the region during the day on the 15th. A round
of widespread light to locally moderate rainfall activity was observed
during the morning hours followed by a more significant round with
thunderstorms during the evening hours in association with a cold front.
Moisture levels associated with this low-pressure system were in the
99th percentile for mid-March, signifying that environment was
favorable for heavier rainfall rates to materialize. As a result of the
heavier rainfall activity observed during the evening hours, flooding was
observed across the Wickenburg area in northwestern Maricopa
County, where over an inch of total rainfall was observed. Flooding was
also observed along the low-water crossings that intersect the
Hassayampa River, which runs from north to south along the western
third of Maricopa County. Strong storms were also observed during the
afternoon hours across southwestern Arizona, producing isolated gusts
around 60 mph in the Yuma area.
March 22-
24, 2023
N/A
N/A
A storm system moving across the west coast in combination with well
above normal moisture levels for mid-March standards with values
above the 99th percentile resulted in waves of light to moderate rainfall
activity across the region. The heaviest rainfall was observed across the
areas to the north and east of Phoenix, where multiple inches of rain
were observed. Given that the flows along rivers, small streams, creeks,
and washes were elevated due to previous precipitation activity from
previous storms and with the additional rainfall that fell, the water levels
rose above alarm stage, resulting in flooding along low-water crossings.
April 1-30,
2023
N/A
N/A
Snowmelt runoff from the anomalous amounts of snow over the
Arizona high terrain led to continued elevated flows in the Salt and
Verde River watersheds. Dam releases being conducted in these
watersheds to deal with the abnormal runoff led to continued
downstream impacts along the Salt and Gila Rivers, which initially
began in March. Continued releases from Granite Reef Dam allowed for
elevated flows to persist in the normally dry Salt River with multiple
unbridged river crossings remaining closed due to flooding. The
heightened flows in the Salt River led to the fatalities of two men who
were caught in an undercurrent while paddle boarding down the river.
Releases from Granite Reef Dam were significantly reduced by the end
of April as runoff into the watersheds decreased. Flow in the Salt and
Gila Rivers continued to travel downstream to Painted Rock Dam.
Releases from this dam led to elevated flows traveling down the Gila
River into Yuma County, leading to numerous additional closures of
unbridged river crossings. Elevated flows in the Salt and Gila Rivers
allowed for impacts to persist into the month of May.
May 1-31,
2023
N/A
N/A
Water being held in the Painted Rock Reservoir from abnormal winter
and early spring runoff continued to be released downstream from April
through the month of May. As a result of these continued releases from
Painted Rock Dam, downstream impacts along the Gila River between
the dam and the Colorado River persisted through the month. Impacts
along the Gila River included continued road closures of multiple
4 | Step 4: Assess the Hazard
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4-41
Date(s) of
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Description
unbridged crossings. Flow in the Gila River began to drop below Action
Stage by the end of the month as releases from Painted Rock Dam
decreased. The long duration high flow that occurred in the Gila River
resulted in multiple unbridged river crossings being damaged.
May 19,
2023
N/A
N/A
An upper-level low pressure system situated near the northern Baja
Peninsula aided in bringing in abnormally high moisture content into
south-central and southwest AZ. Precipitable water values of
approximately 1 were observed, which for mid-May is a record. The
combination of the moisture and instability resulted in the development
of an intense cluster of thunderstorms across the higher terrain zones
northwest of Phoenix during the afternoon hours, with the activity
gradually drifting into northwestern portions of Maricopa County. The
activity affected the Wickenburg area, where strong winds and flash
flooding due to rainfall just over an inch in one hour were reported.
August 31,
2024
N/A
N/A
The overall pattern featured an upper-level low pressure situated along
the west coast and the subtropical high pressure centered over New
Mexico. This overall pattern configuration resulted in southerly flow
across Arizona, which helped transport moisture into the region. Thus,
the environment became conducive for thunderstorm activity across
most of central and southern AZ with a very favorable setup for strong
to severe winds. Thunderstorms first developed over southeast Arizona
and then, with the southerly flow, were steered into south-central AZ.
There were widespread reports of dense blowing dust with visibilities
reduced to 1/4 mile or less as well as wind damage as winds were in
excess of 60 mph. In addition, a training thunderstorm over northern
Maricopa County, in the Anthem area, resulted in 2-4 of rain according
to doppler radar estimates and led to significant flash flooding.
September
13, 2023
N/A
N/A
The synoptic pattern was characterized by strong westerly flow aloft
situated across most of the Desert Southwest with embedded
shortwave energy providing the main source for rising motion. Above
normal moisture was present. The available moisture in combination
with the daytime heating led to the development of moderate instability.
The strong westerly flow aloft led to strong vertical shear. All of these
factors led to a very favorable environment for the development of
strong to severe thunderstorms across portions of south-central AZ.
Scattered thunderstorms started to develop by the early afternoon
hours of the 12th with multiple rounds continuing into the evening
hours. One severe thunderstorm in particular developed near the
Buckeye area, became supercellular, and tracked generally eastward
affecting areas such as Goodyear, Glendale, Phoenix, Scottsdale, Mesa
and Apache Junction, causing extensive straight-line wind damage
along its path. Additional thunderstorms developed just east of the
Phoenix metro area during the overnight and early morning hours of the
13th, with the main impact being isolated flash flooding.
January 23,
2024
N/A
N/A
A shortwave trough moving across the Desert Southwest combined
with well-above normal moisture resulted in multiple rounds of light to
moderate rainfall with embedded thunderstorms across south-central
AZ from the 21st to 23rd. Rainfall rates during these multiple rounds of
rain generally ranged between 0.10-0.50, resulting in storm total
amounts of between 0.5-3 across the region during a 72-hour period.
4 | Step 4: Assess the Hazard
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The highest rainfall amounts were observed across portions of western
Pinal and southwest Maricopa Counties, where there were reports of
flooding.
April 1,
2024
N/A
N/A
An upper-level low pressure system moving across the Desert
Southwest resulted in large scale forcing for ascent with highly
anomalous moisture in place. This result in an area of moderate to
locally heavy rain to develop over the Phoenix metro area with many
areas receiving between 0.5-1 inches. The rainfall was enough to cause
Indian Bend Wash, located in Scottsdale, to reach action stage and thus
cause some flooding along some low water crossings.
July 16-17,
2024
N/A
N/A
The typical afternoon thunderstorm activity developed across the higher
terrain areas of northern and eastern AZ. Most the activity remain
anchored over the high terrain with barely any activity observed across
the lower elevations given the strong convective inhibition in place.
However, the environment was still favorable for any thunderstorm that
developed to become strong. A strong, nearly stationary thunderstorm
developed during the evening hours over the Wildcat Burn Scar in
northern Maricopa County, dumping rainfall amounts in excess of 1.5
inches in less than an hour. This was enough rainfall in a short time
period to result in flood issues in the burn scar area.
July 25,
2024
N/A
N/A
With the subtropical high pressure centered near the Lower Colorado
River Valley, the steering flow pattern across much of eastern and
central AZ was from the north to northeast. Thunderstorm activity
developed across the Mogollon Rim during the late morning into the
early afternoon hours and was steered south to southwestward into
south-central AZ. An upper-level disturbance moving in from New
Mexico helped enhance the vertical ascent and thus resulted in the
thunderstorm coverage to become quite numerous with deep and
colliding outflow boundaries helping to spark new activity across the
lower deserts of south-central AZ. The parameters were favorable for
these thunderstorms to generate strong to severe downburst winds.
The steering flow was very light, resulting in slow storm motions and
thus heavy rainfall leading to isolated instances of flash flooding.
August 3,
2024
N/A
N/A
With the subtropical high-pressure system centered over the Four
Corners Region, the flow across the region was from the southeast.
Thunderstorms developed during the afternoon hours, particularly over
Pima County in southeast AZ, and were steered northwestward towards
western Maricopa County with additional activity developing from
outflow boundaries. Some of the thunderstorm activity was also slow
moving, resulting isolated flash flooding, with the area of Cruff Wash
south of Buckeye reaching bankfull and resulting in flooding along low-
water crossings.
August 7,
2024
N/A
N/A
With the subtropical high-pressure system situated across northern AZ,
the steering flow was from the east. Riding underneath the subtropical
high was an easterly disturbance near the International Border, which
helped enhance the easterly flow at mid-levels upwards of 25 kts as well
as the forcing for ascent. The enhanced easterly flow, which increased
the vertical shear upwards of 25-30 kts, contributed to the overall storm
organization and thus for most of the thunderstorm activity to become
severe. Thunderstorm activity first developed across the higher terrain
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areas of eastern and southeastern AZ with additional activity developing
over the lower deserts via outflow boundaries.
August 22-
23, 2024
N/A
N/A
Thunderstorm activity developed across much of eastern AZ, along the
higher terrain features, during the early afternoon hours. Outflow
boundaries emanating from the activity over the higher terrain areas
sparked a complex of robust thunderstorms over Pinal County. A
northwestward moving outflow boundary that developed from the Pinal
County storms produced wind gusts in excess of 50 mph as well as
areas of dense blowing dust across the Phoenix East Valley. Additional
thunderstorm activity then developed over central Phoenix during the
late afternoon, likely instigated by a convergence zone that set up right
over the area with little convective inhibition in place and thus it did not
take much of a triggering mechanism to get convective initiation.
Source: (National Centers for Environmental Information 2024); (FEMA 2025)
Note:
Data available through November 30, 2024
4.11.5
Probability
One of the most widely adopted design and regulatory standards for flooding in Arizona is an event of a
certain magnitude that has a 1% probability of being equaled or exceeded in any given year, or the 1%
annual chance of exceedance (ACE) flood. The 1% ACE flood is the standard formally adopted by FEMA
for regulatory use and is often referred to with the recurrence interval moniker of “100-year flood.” The
reality is that a community could experience multiple 1% ACE flood events (100-year floods) in any given
year (Arizona Department of Emergency and Military Affairs 2023). However, flooding events below the
100-year flood threshold are a common occurrence in the City of Phoenix, especially urban flooding.
The 2021 Maricopa County Multi-Jurisdictional Hazard Mitigation Plan estimates the probability for
emergency spillway flow and dam failure as unlikely (extremely rare with no documented history of
occurrences or events; annual probability of less than 0.001%) (Maricopa County 2021).
The Arizona State Hazard Mitigation Plan notes that the probability of a FEMA accredited or USACE
Authority levee failing is low (Arizona Department of Emergency and Military Affairs 2023).
4 | Step 4: Assess the Hazard
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
4-44
4.12
FUTURE FLOODING ASSESSMENT
As the City has grown in population and expanded in developed areas over the past several decades, re-
development and additional development are ongoing. Areas that are at continued risk are those areas
along the transition from mountains to urban development, areas behind embankments – particularly
canals – where ponding occurs, new developments where sheet flow is channelized, and older areas of
the City with limited stormwater infrastructure. Projects have been completed, are underway, or planned
to help reduce flood hazards in these areas.
The City is seeing new development on the fringes, particularly in the northern extents of the City limits.
Developments are being designed to help preserve the natural washes as best as possible which promotes
the natural floodplain functions of the area.
Re-development is also occurring within the City with undeveloped lots being infilled or older properties
being replaced with newer often more densified developments.
The likelihood of flooding in these areas is present but has been reduced thanks to state-of-the-art
hydrologic and hydraulic modeling. The modeling helps support the design of the developments to reduce
the flood hazards in the area. The possibility still exists in these areas but with proper modeling, design
review, and construction, the likelihood is greatly reduced.
Climate change could impact these areas as less-frequent, more-intense storm events are to be expected.
These storms could overwhelm areas if they do occur. Flood control dams and levees around the City help
reduce the risks and hazards to people and property, but they are not eliminated. Areas along the transition
from mountain to urban areas and areas along embankments are particularly at risk due to the limited time
to react to the storm event or no way of move the ponded water behind an embankment.
4.13
OTHER NATURAL HAZARDS
The Arizona State Hazard Mitigation Plan addresses 15 hazards with a total of 12 not addressed within
this FMP. This section will describe the severity, history, and probability of these hazards occurring.
•
Drought
o Severity: High
o History: Frequent and ongoing
o Probability: High
o Discussion: Drought is a large concern for a majority of the western United States. It is a
long-term challenge for the City as drought is an ongoing issue throughout Arizona and the
Colorado River Basin. The City has a Drought Management Plan that was adopted in 1990
and updated over the years, and reaffirmed in 2021.
•
Earthquake
o Severity: Low
o History: None within the last 12 months.
o Probability: Low
o Discussion: The City has no major faults and is at minimal risk to earthquakes.
4 | Step 4: Assess the Hazard
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
4-45
•
Extreme Heat
o Severity: High
o History: Frequent and ongoing
o Probability: High
o Discussion: The City, each summer, is subject to significant heat with rising temperatures
beginning typically in May and lasting through September. In 2024, the City had 113
consecutive days over 100 degrees Fahrenheit, with 70 days over 110 degrees Fahrenheit.
Extreme heat is a serious risk to life every summer.
•
Fissure and Land Subsidence
o Severity: Medium
o History: One site within the City is currently under study
o Probability: Medium
o Discussion: With groundwater pumping in the surrounding area for agriculture and drinking
water, earth fissures and land subsidence are risks not only to the City but also to the
surrounding Maricopa County and neighboring Pinal County. Risks within the City are
minimal.
•
Landslide
o Severity: High
o History: None
o Probability: Low
o Discussion: The mountains surrounding the City are mostly rock, which limits the potential
for landslides.
•
Severe Wind
o Severity: High
o History: Limited with monsoon seasons
o Probability: Medium
o Discussion: Monsoon season typically brings higher than normal winds during storm
events. High winds pick up dust from the surrounding areas to create dust storms. High
winds are also likely outside of monsoon season, especially during the changing of seasons
during the month of April. April is typically the windiest month of the year for the City.
•
Wildfire
o Severity: High
o History: Jomax Fire in 2019
o Probability: High
o Discussion: The City has multiple mountain preserves and parks within the City that are at
fire risk with dry conditions. Additionally, to the north of the City is Tonto National Forest
which frequently has to battle with wildfires year-after-year.
•
Winter Storm
o Severity: N/A
o History: N/A
o Probability: N/A
o Discussion: A winter storm in the City is highly unlikely to occur.
5 | Step 5: Assess the Problem
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
5-1
5
STEP 5: ASSESS THE PROBLEM
5.1
VULNERABILITY ASSESSMENT
5.1.1
Summary of Vulnerability
The vulnerability assessment results from the 2021 Maricopa County Multi-Jurisdictional Hazard
Mitigation Plan and information from the USACE National Dam and Levee Databases were used to assess
the City of Phoenix’s vulnerabilities to flooding.
Riverine and alluvial fan flooding impacts were collectively analyzed based on exposure to high hazard
flood zones. Urban flooding was discussed qualitatively as all of the City of Phoenix could potentially
experience urban flooding. For riverine/alluvial fan and urban flooding, the City is highly vulnerable to these
types of hazards.
Dam failure was analyzed based on exposure to emergency spillway inundation and potential inundation
from medium and high hazard dams. Levee failure was analyzed based on population and assets
protected by levees identified in the USACE National Levee Database. Dam and levee failure are less of a
vulnerability to the City, as both the City and the Flood Control District of Maricopa County have robust
dam safety programs with annual inspections and ongoing maintenance work.
5.1.2
Impact on Life, Health, and Safety
The impact of flooding on life, health, and safety is dependent upon several factors including the severity
of the event and whether or not adequate warning time is provided to residents. Exposure represents the
population living in or near floodplain areas that could be impacted should a flood event occur. Additionally,
exposure should not be limited to only those who reside in a defined hazard zone, but everyone who may
be affected by the effects of a hazard event (e.g., people are at risk while traveling in flooded areas, or their
access to emergency services is compromised during an event). The degree of that impact will vary and
is not strictly measurable.
Riverine Flooding and Alluvial Fan Flooding
Table 5-1 displays the population in the City of Phoenix exposed to high hazard flood zones. The 2021
Maricopa County Multi-Jurisdictional Hazard Mitigation Plan found that 34,577 people (2.21% of the City
population) are located in high hazard flood zones (Maricopa County 2021).
Table 5-1. Population Exposure to High Hazard Flood Zones
Total
Population
Total
Population
Exposed to
High Hazard
Flood Zones
Percentage
Population
Exposed to
High Hazard
Flood Zones
Total Population
Over 65
Total Population
Over 65 Exposed to
High Hazard Flood
Zones
Percentage of Total
Population Over 65
Exposed to High
Hazard Flood Zones
1,561,296
34,577
2.21%
143,448
2,701
1.88%
Source: (Maricopa County 2021)
5 | Step 5: Assess the Problem
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
5-2
Urban Flooding
Urban flooding is traditionally shallow flooding, focused on roadways. The Centers for Disease Control and
Prevention report that over half of all flood-related drownings occur when a vehicle is driven into hazardous
flood water. The next highest percentage of flood-related deaths is due to walking into or near flood waters.
People underestimate the force and power of water. Many of the deaths occur in cars swept downstream.
Many of these drownings are preventable. A mere 6 inches of fast-moving flood water can knock over an
adult. It takes just 12 inches of rushing water to carry away most cars and just 2 feet of rushing water can
carry away SUVs and trucks (NWS n.d.).
Dam and Levee Failure Flooding
Table 5-2 displays the population in the City of Phoenix exposed to emergency spillway inundation. In total,
224,541 in the City of Phoenix (14.38% of the City population) are exposed to emergency spillway
inundation (Maricopa County 2021). Table 5-3 displays the population exposed to the dam failure
inundation in Maricopa County. No residents are anticipated to be exposed to the dam failure inundation
hazard area (Maricopa County 2021).
Table 5-2. Population Exposure Due to Emergency Spillway Inundation
Total
Population
Total
Population
Exposed to
Emergency
Spillway
Inundation
Percentage
Population
Exposed to
Emergency
Spillway
Inundation
Total Population
Over 65
Total Population
Over 65 Exposed to
Emergency Spillway
Inundation
Percentage of Total
Population Over 65
Exposed to
Emergency Spillway
Inundation
1,561,296
224,541
14.38%
143,448
24,137
17.06%
Source: (Maricopa County 2021)
Table 5-3. Population Exposure Due to Dam Failure Inundation
Dam
Hazard
Level
Total
Population
Total
Population
Exposed
Percentage
Population
Exposed
Total Population
Over 65
Total Population
Over 65 Exposed
Percentage of
Total Population
Over 65 Exposed
High
1,561,296
0
0%
143,448
0
0%
Medium
1,561,296
0
0%
143,448
0
0%
Source: (Maricopa County 2021)
According to the National Levee Database, levees in the City of Phoenix protect 69,582 people (USACE
2025). The failure of levees could threaten this population. Refer to Table 4-4 for more information on each
levee.
Warning and Evacuating
The City does an annual exercise to support review and improvements of their emergency action plans.
These documents are done either as a tabletop exercise or full-scale exercise to go through the response
to a flood event or potential dam/levee failure. The City also has plans for evacuation with the Emergency
Management department.
5 | Step 5: Assess the Problem
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
5-3
Flood Water Health Impacts and Mold
In the event of a flood at a structure, health impacts are a significant hazard, especially mold. Homes could
experience little flooding but be impacted by mold long-term. Riverine and urban flooding present the most
risk to health and the presence of mold due to their increased likelihood, as compared to dam and levee
failure. The City has resources to support residents and property owners in the event of a flood event to
help get the support needed to get the structure back into a healthy state.
5.1.2.1
Socially Vulnerable Populations
Social vulnerability is defined as the susceptibility of social groups to the adverse impacts of natural
hazards, including disproportionate death, injury, loss, or disruption of livelihood. Social vulnerability
considers the social, economic, demographic, and housing characteristics of a community that influence
its ability to prepare for, respond to, cope with, recover from, and adapt to environmental hazards.
Socially vulnerable populations are most susceptible to flood events based on several factors, including
their physical and financial ability to react or respond during a flood. Vulnerable populations include
homeless persons, elderly (over 65 years old), low income or linguistically isolated populations, people with
life-threatening illnesses, and residents that may struggle to evacuate. The population over the age of 65
is also more vulnerable. They may require extra time to evacuate or need assistance to evacuate and are
more likely to seek or need medical attention.
Riverine Flooding and Alluvial Fan Flooding
The 2021 Maricopa County Multi-Jurisdictional Hazard Mitigation Plan found that 2,701 people over the
age of 65 are located in high hazard flood zones (Maricopa County 2021).
Urban Flooding
Urban flooding traditionally is shallow flooding, focused on roadways. Residents that walk to work because
they lack access to a personal vehicle are likely to choose to walk through flooded roadways, exposing
themselves to drowning risks.
Dam and Levee Failure Flooding
24,137 people over the age of 65 are exposed to emergency spillway inundation in the City of Phoenix. No
socially vulnerable populations are exposed to dam failure inundation (Maricopa County 2021).
5.1.3
Impact on General Building Stock
Flooding can severely impact buildings by causing structural damage to foundations, walls, and floors,
damaging electrical systems, contaminating water supplies, and leading to significant property loss,
particularly when buildings are located in floodplains (FEMA 2022).
Riverine Flooding and Alluvial Fan Flooding
The 2021 Maricopa County Multi-Jurisdictional Hazard Mitigation Plan found that in the City of Phoenix,
11,833 structures (2.0% of the City’s residential building stock) are located in high hazard flood zones
(Maricopa County 2021).
5 | Step 5: Assess the Problem
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
5-4
Table 5-4. Residential Structure Exposure Due to High Hazard Flood Zones
Residential
Building
Count
Total
Residential
Buildings
Exposed to
High Hazard
Flood Zones
Percentage
Residential
Buildings
Exposed to
High Hazard
Flood Zones
Total Residential
Building
Replacement Value
Residential Building
Replacement Value
Exposed to High
Hazard Flood Zones
Percentage of
Residential Building
Replacement Value
Exposed to High
Hazard Flood Zones
590,476
11,833
2.0%
$167,455,500,000
$3,355,733,000
2.0%
Source: (Maricopa County 2021)
Urban Flooding
Urban flooding traditionally is shallow flooding, focused on roadways. Unless extremely severe, urban
flooding does not usually result in damage to buildings.
Dam and Levee Failure Flooding
The 2021 Maricopa County Multi-Jurisdictional Hazard Mitigation Plan found that 90,618 of the City of
Phoenix’s residential building structures (15.35% of the City’s residential building stock) are exposed to
emergency spillway inundation. No residential structures in the City of Phoenix are exposed to dam failure
inundation from high or medium hazard dams (Maricopa County 2021).
Table 5-5. Residential Structure Exposure Due to Emergency Spillway Inundation
Residential
Building
Count
Total
Residential
Buildings
Exposed
Percentage
Residential
Buildings
Exposed
Total Residential
Building
Replacement Value
Residential Building
Replacement Value
Exposed
Percentage of
Residential Building
Replacement Value
Exposed
590,476
90,618
15.35%
$167,455,500,000
$25,698,678,000
15.35%
Source: (Maricopa County 2021)
Table 5-6. Residential Structure Exposure Due to Dam Failure Inundation
Dam
Hazard
Level
Residential
Building
Total
Residential
Buildings
Exposed
Percentage
Residential
Buildings
Exposed
Total Residential
Building
Replacement
Value
Residential
Building
Replacement
Value Exposed
Percentage of
Residential
Building
Replacement
Value Exposed
High
590,476
0
0%
$25,698,678,000
0
0%
Medium
590,476
0
0%
$25,698,678,000
0
0%
Source: (Maricopa County 2021)
According to the National Levee Database, levees in the City of Phoenix protect 12,528 buildings (USACE
2025). Failure of levees could threaten these buildings. Refer to Table 4-4 for more information on each
levee.
5.1.4
Impact on Critical Facilities and Infrastructure
Critical facilities and infrastructure can be at high risk to flooding events. Flooding often can result in
impassable roadways, reducing or eliminating access to critical services. Flooding can result in utility
failure and the contamination of drinking water.
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2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
5-5
Table 5-7. Critical Facilities and Infrastructure Most Likely Impacted by Flood
Lifeline
Categories
Notable Impacts
Safety and
Security
Community safety may be threatened due to potential direct harm from flooding and
compounding effects on administration of services. Transportation infrastructure issues
may directly impact the abilities of law enforcement, fire service, search and rescue, and
other government services to respond to a flooding hazard.
Food, Hydration,
Shelter
Flooding can cause damage to structures which provide shelter, and the food that people
store in those structures. while the food supply chain may be disrupted due to impacts on
agricultural production and transportation infrastructure.
Health and
Medical
Medical facilities can be impacted due to damage to structures from flooding, while patient
movement and medical supply chains can be impacted by effects on transportation
infrastructure.
Energy
Components of electric power generation, transmission and distribution systems are at risk
for damage by floods, potentially resulting in service failure. Flooding can also adversely
impact oil and gas production and electricity generation impacting energy supply.
Communications
Flooding can damage telecommunications equipment. Communications can also be
impacted by power outages caused by flooding. This can impact response coordination.
Transportation
Flooding can strain the Transportation lifeline in both the short- and long-term through
transportation delays and infrastructure damage. When flooding occurs on roadways, it
can make transportation dangerous or even impossible. Damage to the Transportation
lifeline has cascading effects among other lifelines which depend on movement of people
or goods.
Hazardous
Materials
The Hazardous Materials lifeline could be impacted by flooding. Facilities may be directly
impacted, or transport of hazardous materials could be hindered by flooded infrastructure.
Flooding of contaminated sites can uproot those hazardous materials which may be
present and transport them amongst the floodwaters.
Water Systems
Flooding could pose a threat to the Water System lifeline. Floods can damage drinking
water wells and lead to aquifer or well contamination. Sewage systems especially those
that are combined may be affected leading to backups in sewer pipes or direct overflow
discharge of sewage into water sources.
Source: (NJOEM 2024)
Riverine Flooding and Alluvial Fan Flooding
The 2021 Maricopa County Multi-Jurisdictional Hazard Mitigation Plan found that 15 community facilities
in the City of Phoenix (1.58% of the City’s total facilities) are located in high hazard flood zones (Maricopa
County 2021).
Table 5-8. Asset Inventory Exposure to High Hazard Flood Zones
Total Facilities
in the
Community
Impacted
Facilities
Percentage of
Total
Community
Facilities
Impacted
Total Replacement Value
of All Facilities Reported
by Community
Estimated Replacement
Value of Facilities Exposed
to Hazard
947
15
1.58 %
$7,843,312,000
$111,523,000
Source: (Maricopa County 2021)
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2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
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Urban Flooding
Urban flooding traditionally is shallow flooding, focused on roadways and heavily impacted the
transportation lifeline. In most instances, flooding results in service interruptions and roadways are not
passable, but severe floods may result in damages to the roadway infrastructure.
Dam and Levee Failure Flooding
The 2021 Maricopa County Multi-Jurisdictional Hazard Mitigation Plan found that 96 facilities in the City
of Phoenix (10.14% of the City’s total community facilities) are exposed to emergency spillway inundation.
No facilities in the City of Phoenix are exposed to dam failure inundation from high or medium hazard
dams (Maricopa County 2021).
Table 5-9. Asset Inventory Exposure Due to Emergency Spillway Inundation
Total Facilities
in the
Community
Impacted
Facilities
Percentage of
Total
Community
Facilities
Impacted
Total Replacement Value
of All Facilities Reported
by Community
Estimated
Replacement
Value Exposed to
Hazard
947
96
10.14%
$7,843,312,000
$455,408,000
Source: (Maricopa County 2021)
Table 5-10. Asset Inventory Exposure Due to Dam Failure Inundation
Dam Hazard Level
Total
Facilities in
the
Community
Impacted
Facilities
Percentage
of Total
Community
Facilities
Impacted
Total Replacement
Value of All Facilities
Reported by
Community (x
$1,000)
Estimated
Replacement
Value Exposed to
Hazard
(x $1,000)
High Hazard
947
0
0.00%
$7,843,312
$0
Medium Hazard
947
0
0.00%
$7,843,312
$0
Source: (Maricopa County 2021)
According to the National Levee Database, levees in the City of Phoenix protect 14 critical facilities (USACE
2025). Failure of levees could threaten these facilities. Refer to Table 4-4 for more information on each
levee.
5.1.5
Impact on the Economy
Flooding can result in a variety of environmental impacts including damage to structures, cleanup costs,
and lost wages. Even minor flooding can result in damages to agriculture. According to the 2022 Census
of Agriculture, Maricopa County is home to 1,527 farms with a total of $1.558 billion in annual market value
sold (USDA 2022).
Riverine Flooding and Alluvial Fan Flooding
The 2021 Maricopa County Multi-Jurisdictional Hazard Mitigation Plan found that $3,355,733,000 of the
City’s residential building replacement cost value (2.0% of the City’s total residential building replacement
cost value) is located in high hazard flood zones. An additional $111,523,000 in community facility
5 | Step 5: Assess the Problem
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
5-7
replacement cost value is exposed (Maricopa County 2021). See Table 5-4 and Table 5-8 for more
information.
Urban Flooding
Urban flooding is traditionally shallow flooding, focused on roadways. While structures and facilities are
not exposed, vehicles can be damaged if they are parked in areas that flood or attempt to drive through
flooded roadways. This may result in costs for cleanup, replacement of parts, or total loss of the vehicle.
According to Carfax, Arizona ranks 29th out of the top 100 metros for having flood-damaged cars in the
market (ABC15 2024).
Dam and Levee Failure Flooding
The 2021 Maricopa County Multi-Jurisdictional Hazard Mitigation Plan found that no residential structures
are exposed to dam failure inundation from medium and high hazard dams, but $25,698,678,000 in
residential building value is exposed to emergency spillway inundation in the City of Phoenix. See Table
5-5 and Table 5-6 for more information. Additionally, $455,408,000 in community facilities are exposed to
emergency spillway inundation (Maricopa County 2021).
According to the National Levee Database, levees in the City of Phoenix protect roughly $8.067 billion in
property value (USACE 2025). Failure of levees could threaten this property value. Refer to Table 4-4 for
more information on each levee.
5.1.5.1
Review of Damaged Buildings and Flood Insurance Claims
The City of Phoenix participates in the National Flood Insurance Program (NFIP). Participating in the NFIP
is voluntary and to join, a community must complete an application; adopt a resolution of intent to
participate and cooperate with FEMA; and adopt and submit a floodplain management ordinance that
meets or exceeds the minimum NFIP criteria, and the ordinance must also adopt any FIRM or FHBM for
the community. By participating, communities agree to adopt and implement local floodplain management
regulations that protect lives and reduce risk from future flooding. In return, the federal government makes
flood insurance available to property owners throughout the community (FEMA 2020) (FEMA 2022).
There are 3,352 NFIP policies in the City of Phoenix. These policies contribute roughly $2.5 million in annual
premiums and have an insurance in force of $887 million. There have been 1,283 claims for a total payment
of $8.9 million. It should be noted that this information is strictly limited to structures that are insured
through the NFIP. Other structures may have flood insurance through private insurers.
According to the most recent available data from FEMA, there are 53 repetitive loss properties and 5 severe
repetitive loss properties in the City of Phoenix (FEMA 2023a). The occupancy class of these properties
was not available for this FMP update. According to FEMA, a repetitive loss (RL) property is a NFIP-insured
structure that has had at least two paid flood losses of more than $1,000 in any 10-year period since 1978.
A severe repetitive loss (SRL) property is a NFIP-insured structure that has had four or more separate claim
payments made under a standard flood insurance policy, with the amount of each claim exceeding $5,000
and with the cumulative amount of such claims payments exceeding $20,000; or at least two separate
claims payments made under a standard flood insurance policy with the cumulative amount of such claim
payments exceed the fair market value of the insured building on the day before each loss (FEMA 2022).
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2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
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Table 5-11 summarizes the NFIP community statistics for the City of Phoenix.
Table 5-11. National Flood Insurance Program Statistics
Total
Policies
Total
Premiums
Total Insurance in
Force
Total
Claims
Total Payment
Repetitive
Loss
Properties
Severe
Repetitive
Loss
Properties
3,352
$2,555,011
$887,441,000
1,283
$8,946,137
53
5
Source: (FEMA 2025); (FEMA 2023a)
Notes: Total policies, total premiums, total insurance in force, total cliams, and total payment data current as of 3/3/2025.
Repetitive Loss and Severe Repetitive Loss data current as of 9/11/2023
5.1.6
Impact on Historic and Cultural Resources
The City of Phoenix is home to 54 historic districts and has a large inventory of historic and cultural
resources (Phoenix 2024). Historic structures were not constructed to the modern building code and are
less likely to be able to withstand the forces of flooding. This may result in structures being pushed off
their foundations, collapses, and other failures. Historic structures in the floodplain are also very unlikely
to be built to the modern design elevation, making them more likely to be damaged by flooding events.
5.1.7
Impact on Ecosystems and Natural Resources
The environmental impacts of a flood can include significant water quality and debris-disposal issues.
Flood waters can back up sanitary sewer systems and inundate wastewater treatment plants, causing raw
sewage to contaminate residential and commercial buildings and the flooded waterway. The contents of
unsecured containers of oil, fertilizers, pesticides, and other chemicals get added to flood waters.
Hazardous materials may be released and distributed widely across the floodplain. Water supply and
wastewater treatment facilities could be offline for weeks. After the flood waters subside, contaminated
and flood-damaged building materials and contents must be properly disposed of. Contaminated sediment
must be removed from buildings, yards, and properties. In addition, severe erosion is likely; such erosion
can negatively impact local ecosystems.
As the City of Phoenix's development has expanded, a priority to preserve natural corridors for drainage
has been implemented. This not only preserves the natural functions of the washes within the area, but
also allows for a more natural ecosystem with pathways for wildlife to traverse. Internally, an initiative for
Green Stormwater Infrastructure and Low Impact Development has been ongoing. Within an urban
environment, Green Stormwater Infrastructure and Low Impact Development will mimic natural floodplain
functions by attenuating flow and also improving stormwater quality.
5.1.8
Impact of Future Population on Flooding
The population for the City of Phoenix and the surrounding area is forecast to continued growing. Increases
in population result in more potential exposure to flooding. Increased stormwater requirements and more
detailed hydrologic and hydraulic modeling will help reduce the impacts of flooding on the growing
population. This includes population increases for those who live within the City of Phoenix and those in
5 | Step 5: Assess the Problem
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
5-9
the broader municipal planning area that are likely to work or travel through the City of Phoenix. Table 5-12
displays the projected population growth for the Phoenix Municipal Planning Area.
Table 5-12. Population Projections for the Phoenix Municipal Planning Area
2020
2030
2040
2050
2060
1,665,200
1,867,300
2,007,800
2,101,500
2,184,600
Source: (Maricopa Assosciation of Governments 2025)
5.1.9
Impact of Development on Flooding
Increased development is likely to result in greater levels of runoff which can increase the frequency and
severity of flooding. Development that occurs within the floodplain will be at a higher risk to flooding
impacts.
High hazard flood zones throughout Phoenix are primarily located along established watercourses,
conveyance corridors, canals, and flood control facilities. Development changes anticipated for the
northwest part of the City include a new industrial development at the northwest corner of Loop 303 and
I-17. Continued active commercial and residential development in the northeast areas of the City are
currently located within an alluvial fan flood zone that is planned for mitigation. Other new developments
throughout the City will be regulated per the City’s floodplain management ordinance and drainage design
policies (Maricopa County 2021).
The majority of new development within the City of Phoenix is associated with infill development and
residential development within the southwest area of the City. As the development efforts do not lie within
areas of levee failure hazard, development changes will not impact this hazard (Maricopa County 2021).
Additional development in the northern section of the City is underway. With the completion of a
semiconductor manufacturing facility in the north part of Phoenix, development will move into the area
where currently no development is present. The City will support developers wanting to preserve washes
and drainage corridors to keep the natural floodplain functions in the area.
The City has dedicated mountain preserves where natural floodplain functions will persist to help reduce
flood impacts to properties downstream.
5.1.10
Impact of Climate Change on Future Flooding
Overall, climate change is likely to result in more frequent and more severe flooding in the City of Phoenix.
The Fourth National Climate Assessment (NCA) report (U.S. Global Change Research Program 2018) is
relatively silent on non-coastal flood-related impacts except as they are indirectly influenced by deepening
drought, increased wildfire potential, etc. Prior work in the 3rd Edition (U.S. Global Change Research
Program 2014) notes that one of the anticipated impacts of climate change for the Southwest is a shift in
rain patterns with more intense winter rains, less snow, and less frequent but more intense monsoon-
related thunderstorms. A reduction in average annual precipitation and streamflow volumes. For Northern
Region communities, the impacts could result in more severe winter season flooding. A second study by
Luong (Thang M. Luong 2017) notes that monsoon thunderstorms in the Central and Southern Regions of
5 | Step 5: Assess the Problem
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the state have become more intense over a recent 20-year period (1991- 2010) when compared to events
recorded in the past (1950-1970). The study concludes that the trend will likely continue as the
temperatures rise and provide more moisture storage capacity in the lower atmosphere. The increased
intensities may result in increased flood levels. Statewide, the overall flooding conditions could also be
exacerbated by watersheds with reduced vegetation due to increases in drought or wildfire conditions
(Arizona Department of Emergency and Military Affairs 2023).
From a dam safety perspective, the primary climate change impacts will be related to potential changes in
the way precipitation and resultant flood patterns may vary and influence the potential for increased
wildfire activity. The Fourth National Climate Assessment (NCA) report (U.S. Global Change Research
Program 2018) notes that one of the anticipated impacts of climate change for the Southwest is a
reduction in average annual precipitation and streamflow volumes. The report and supporting documents
also indicate that winter storm intensities are anticipated to increase, which may lead to increased event-
based flooding. The NCA report also notes that winter precipitation will be less in the form of snow and
more frequent rain, which may indicate more frequent winter flooding. The potential for reduced vegetation
could also exacerbate the overall flooding conditions for watersheds upstream of dam facilities due to
increased drought and post-wildfire flooding conditions (Arizona Department of Emergency and Military
Affairs 2023).
Climate change impacts to emergency spillway and dam failure inundation hazard are anticipated to occur
in relation to the assumed increase in wildfire occurrences. Wildfires typically change a watershed’s
hydrology with regard to rainfall-runoff processes, causing significant increases in peak discharge and
runoff volumes during precipitation events. Dams and flood regulation service supplies located in the
county are typically not designed for post wildfire flooding volumes and flow rates and could pose
significant increased risks of emergency spillway operation or failure should a large wildfire occur in the
watershed. Other indirect impacts could be linked to increased presence of fissure and subsidence due to
increased groundwater withdrawal due to reduced surface water supplies (Maricopa County 2021).
From a levee safety perspective, the primary climate change impacts will be related to potential changes
in the way precipitation and resultant flood patterns may vary, and influence of the potential for increased
wildfire activity (Arizona Department of Emergency and Military Affairs 2023).
5.2
PROBLEM SUMMARY
After review of the capability assessment and the vulnerability assessment the following flood related
problems have been identified:
•
Additional stormwater and floodplain management education is needed for City leaders,
Councilmembers, and Neighborhood Services.
•
Additional education is needed for the City Council.
•
Additional written outreach is needed for the public, City leaders, policy makers, and the City’s
Neighborhood Services department.
•
Regular social media outreach is needed for floodplain education.
5 | Step 5: Assess the Problem
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
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•
Regular stormwater outreach should be deployed through direct mailings.
•
Outreach could be delivered to neighborhood association meetings, festivals, and garden shows.
•
Additional public education on the importance of dams and their risks is needed.
•
Properties in repetitive loss areas require education on flood risks and potential mitigation
measures.
•
Continued dam safety and flood response exercises are needed to maintain high levels of
emergency preparedness.
•
Coordination is needed among local and regional agencies for flood warning and emergency
response.
•
City staff should attend regular trainings for emergency response and floodplain management.
•
Coordination is needed to develop a network of Continuously Operating Reference Stations (CORS).
•
The City lacks a Substantial Damage Response Plan to coordinate identification, evaluation, and
mitigation of substantially damaged properties.
•
Annual education is needed to provide the public with recommendations for proper vegetation
maintenance and flood preparedness.
•
Requirements for new developments should be evaluated to preserve natural floodplain function
and encourage green stormwater techniques.
•
Capital Improvement Program projects to reduce flood risk should continue to be identified and
supported.
•
Critical infrastructure and facilities should be mapped to determine flood exposure.
•
Critical infrastructure and facilities should be evaluated for flood risks.
•
Flood fighting materials (sand and bags) should be stockpiled near critical infrastructure and
facilities.
•
Critical infrastructure and facilities inventories should be regularly updated to keep up to date for
potential flood mitigation.
•
Emergency Action Plans should address flood response scenarios for City-owned critical
infrastructure and facilities.
•
Emergency Action Plan contact list and notification charts should be updated annually.
•
Maintenance at floodprone areas should be tracked.
•
Drywell maintenance should be monitored.
•
The City’s 311 App and webpage for reporting flood maintenance issues should be better
advertised to increase use.
•
Stormwater maintenance work by the City should be publicized.
•
Stormwater and floodplain requirements, zoning and subdivision ordinances, guidelines,
regulations, codes, design manuals, and land use plan should be annually evaluated for updates
and potential improvements to reduce future flood risks.
•
Building Codes should be regularly evaluated for updates and potential improvements to reduce
future flood risks.
•
The public needs guidance on vegetation maintenance for privately owned wash corridors, storm
drain inlets and outlets, and stormwater storage basins.
5 | Step 5: Assess the Problem
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•
City-owned storm drain infrastructure should be evaluated for maintenance and rehabilitation
needs.
•
Flood mitigation funding needs could be supported by General Obligation Bond funding.
•
Flood mitigation funding needs could be supported by state and federal funding opportunities.
•
Continued partnership with the Flood Control District of Maricopa County is needed to support
flood mitigation projects.
•
Additional funding resources for stormwater project funding should be explored.
6 | Step 6: Set Goals
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6
STEP 6: SET GOALS
Mitigation goals represent broad statements that are consistent with the hazards identified in the FMP and
achieved through the implementation of specific mitigation actions. Mitigation objectives are defined,
short-term, measurable efforts that lead to achieving an overall goal. Mitigation goals and objectives
provide the guidance for the development of the mitigation actions.
6.1
PREVIOUS GOALS AND OBJECTIVES
6.1.1
Previous FMP Goals
The 2016 City of Phoenix Floodplain Management Plan and the 2021 Maricopa County Multi-Jurisdictional
Hazard Mitigation Plan had a single overarching goal: Reduce or eliminate the risk to people and property
from natural hazards.
6.1.2
Previous FMP Objectives
The objectives for the 2016 City of Phoenix Floodplain Management Plan and the 2021 Maricopa County
Multi-Jurisdictional Hazard Mitigation Plan were as follows:
1. Reduce or eliminate risks that threaten life and property in the incorporated, unincorporated, and
tribal jurisdictions within City of Phoenix/Maricopa County.
2. Reduce risk to critical facilities and infrastructure from natural hazards.
3. Promote hazard mitigation throughout the incorporated, unincorporated, and tribal jurisdictions
within City of Phoenix/Maricopa County.
4. Increase public awareness of hazards and risk that threaten the incorporated, unincorporated, and
tribal jurisdictions within City of Phoenix/Maricopa County.
6.2
UPDATED GOALS, AND OBJECTIVES
The FMP Committee reviewed the goals from the 2016 City of Phoenix Floodplain Management Plan and
the 2021 Maricopa County Multi-Jurisdictional Hazard Mitigation Plan and identified the following
opportunities for modifications for 2025 FMP:
•
The prior objectives could be converted to goals.
•
A goal could be established to encourage proper maintenance and preventative measures for
stormwater infrastructure.
•
The public awareness goal could be expanded to include policy makers and city leaders.
•
A goal targeting the effective use of public funding could be established.
6 | Step 6: Set Goals
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6.2.1
2025 FMP Goals
The updated goals for the 2025 FMP are as follows:
•
Goal 1: Educate the public, policymakers, and City leaders on stormwater and floodplain
management and risks.
•
Goal 2: Coordinate with other jurisdictions and agencies to mitigate flooding hazards and improve
emergency response.
•
Goal 3: Reduce the danger of flood hazards to people, property, critical infrastructure/facilities, and
natural resources.
•
Goal 4: Enhance proactive maintenance and preventive measures for stormwater infrastructure.
•
Goal 5: Utilize public funding in the most effective manner for stormwater and floodplain
management.
7 | Step 7: Review Possible Activities
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7
STEP 7: REVIEW POSSIBLE ACTIVITIES
7.1
STATUS OF PREVIOUS ACTIONS
For the 2025 FMP, the actions from the 2016 City of Phoenix Floodplain Management Plan and the 2021
Maricopa County Multi-Jurisdictional Hazard Mitigation Plan were reviewed by the FMP Committee and
each identified lead department.
7.1.1
2016 City of Phoenix Floodplain Management Plan
The 2016 Floodplain Management Plan included an action plan comprised of 18 actions. These actions
are described in Table 7-1.
Table 7-1. Actions from the 2016 City of Phoenix Floodplain Management Plan
Action
Description
Deadline
Administrative Actions
1
Plan Adoption
October 2016
2
Monitoring and Reporting
October – annually
3
Community Rating System
CRS Recertification Visit
Program Action Items
4
Dam Improvements
Continuous Activity
5
Levee Improvements
Continuous Activity
6
Drainage system maintenance
Continuous Activity
7
Drainage system improvements
October 2016
8
Property protection funding
October 2016
9
Regulatory review
CRS Recertification Visit
10
NFIP administration
After Community Assistance Contact (CAC)
11
Certified Floodplain Managers
October 2016
12
Flood response plan
Continuous Activity
Public Information Action Items
13
Newspaper notifications
Continuous Activity
14
City Notes articles
Continuous Activity
15
City Website
October 2016
16
Technical References
CRS Recertification Visit
17
Public information projects
Continuous Activity
18
Public information messages
Continuous Activity
7 | Step 7: Review Possible Activities
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7.1.2
2021 Maricopa County Multi-Jurisdictional Hazard Mitigation Plan
The 2021 Maricopa County Multi-Jurisdictional Hazard Mitigation Plan included 20 mitigation actions
specific to the City of Phoenix. The flood related actions are included in Table 7-2.
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7 | Step 7: Review Possible Activities
Table 7-2. Flood Related Mitigation Actions from the 2021 Maricopa County Multi-Jurisdictional Hazard Mitigation Plan
Action
Description
Hazard(s) Mitigated
Community Assets
Mitigated (Ex/New)
Estimated Cost
Priority Ranking
Planning Mechanism(s)
for Implementation
Anticipated Completion
Date
Primary Agency/Job Title
Responsible for
Implementation
Funding Source
1
Review building
permits for
compliance with
Floodplain Ordinance
and NFIP
regulations.
Flood, Dam
Inundation
Both
Staff time
High
Staff Training,
Plan Review
Annual-
Ongoing
Public Works /
Floodplain
Manager
General Funds
2
Continue to include
in the General Plan
policies that protect
the natural flow
regime of washes,
designate areas for
Open Space and
Preserves, and when
fiscally possible
support the use of
green stormwater
infrastructure/ low
impact development
to address multiple
risks.
Flood, Dam
Inundation,
Extreme
Heat,
Drought
Both
Staff time
High
Land
acquisition and
natural
resource
protection
Annual-
Ongoing
Parks and
Recreation/PPPI
Administrator
Phoenix Parks
Preserves
Initiative;
General Fund;
Bonds
3
Storm Drain CIP
Program. Construct
drainage facilities to
mitigate flooding
Flood, Levee
Failure
Both
Variable
High
Staff Training,
Plan Review,
Design and
Construction
Ongoing
Street
Transportation
Department/
Deputy Street
Bonds/Impact
Fees
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7 | Step 7: Review Possible Activities
Action
Description
Hazard(s) Mitigated
Community Assets
Mitigated (Ex/New)
Estimated Cost
Priority Ranking
Planning Mechanism(s)
for Implementation
Anticipated Completion
Date
Primary Agency/Job Title
Responsible for
Implementation
Funding Source
hazard to residents
of the city.
Transportation
Director
4
Coordinate review
and approval of
development
projects located
within flood hazard
areas with PDD and
Floodplain
Management.
Flood,
Extreme
Heat
Both
Staff time
High
GIS
Annual -
ongoing
Planning and
Development
Department /
Planning
Researcher
Enterprise
8
Revise and ratify the
General Plan every
ten years.
Flood
Both
Staff time
Medium
State statute;
Smart Growth
Requirement
Ongoing
Planning and
Development
Department/
Planning Manager
General Fund
9
Update and adopt a
revised building
code.
Flood,
Severe
Wind,
Excessive
Heat
Both
Staff time;
Materials
Medium
Staff training;
Community
Outreach; Plan
review
Annual -
ongoing
Planning and
Development
Department /
Assistant Director
Permit fees
10
Continue to ensure
zoning stipulations
are met before
construction permits
are issued, and
zoning is compatible
Flood,
Excessive
Heat
Both
Staff time
Medium
Zoning
Ordinance;
Staff training;
Plan review
Annual -
ongoing
Planning and
Development
Department /
Deputy Director
Permit fees
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7 | Step 7: Review Possible Activities
Action
Description
Hazard(s) Mitigated
Community Assets
Mitigated (Ex/New)
Estimated Cost
Priority Ranking
Planning Mechanism(s)
for Implementation
Anticipated Completion
Date
Primary Agency/Job Title
Responsible for
Implementation
Funding Source
with the zoning
ordinance.
11
Dam/Levee Safety
Program – Operate
and Maintain
Dams/Levees to
mitigate flooding
hazard to the
residents of the city.
Flood, Dam
Inundation,
Levee
Failure
Both
Staff Time,
Materials
Medium
Staff Training,
Plan Review
Annual -
ongoing
Street
Transportation
Department /
Deputy Street
Transportation
Director
General Funds
12
Continue to provide
links on the
Phoenix.gov/Office
of Emergency
Management
website to sources
of hazard mitigation
educational
materials such as
FEMA.gov and
Ready.gov
Dam
Inundation,
Drought,
Flood,
Severe
Wind,
Wildfire
Both
Staff Time
Medium
N/A
Annual -
ongoing
Office of
Homeland
Security and
Emergency
Management, City
of Phoenix IT
General Funds
16
Design and construct
Rio Salado Oeste in
Salt River (19th Ave-
83rd Ave), including
low flow channel
improvements and
riparian/xeri-riparian
Flooding
and extreme
heat
Both
Staff time,
design and
construction
expenses
High
Rio
Reimagined,
Land
acquisition,
design and
construction
2030
Parks and
Recreation
Department/
Natural Resource
Division Deputy
Director
TBD;
anticipated
USACE Civil
Works project
funds and local
city match
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7 | Step 7: Review Possible Activities
Action
Description
Hazard(s) Mitigated
Community Assets
Mitigated (Ex/New)
Estimated Cost
Priority Ranking
Planning Mechanism(s)
for Implementation
Anticipated Completion
Date
Primary Agency/Job Title
Responsible for
Implementation
Funding Source
vegetation to
improve flow
conveyance and
increase native
vegetation/ habitat.
20
Implement a
notification system
for Downtown
Phoenix businesses
to raise hazard
awareness and
provide advanced
warning of potential
threats in the area.
All Hazards
Both
TBD, plan to
put out RFP
Q2 2021
High
Downtown
Phoenix
Business
Master Plan
2022
Downtown
Phoenix
Partnership/
Strategy and
Community
Affairs
TBD
7 | Step 7: Review Possible Activities
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For each action in the previous flood mitigation strategy, the FMP Committee and each identified lead
department provided a status update using the guidance below:
•
No Progress – The mitigation action has not been completed.
•
In Progress – Implementation of the mitigation action has begun but has not been completed.
•
Ongoing Capability – The mitigation action has been implemented and will be completed on an
annual or regular basis (for example, maintenance activities, annual outreach, etc.).
•
Completed – The mitigation action has been fully implemented and was removed from the updated
mitigation strategy.
The results of this review are provided in Table 7-3.
Table 7-3. Review of Previous Flood Mitigation Actions
Action
Description
Status Update
2016 Phoenix
FMP-1
Plan Adoption
Completed. City Council adopted the
previous FMP on June 22, 2016.
2016 Phoenix
FMP-2
Monitoring and Reporting
Ongoing Capability. Annually
completed.
2016 Phoenix
FMP-3
Community Rating System
Ongoing Capability. CRS Recertification
Visit annually completed.
2016 Phoenix
FMP-4
Dam Improvements
Ongoing Capability. Continuous activity.
2016 Phoenix
FMP-5
Levee Improvements
Ongoing Capability. Continuous activity.
2016 Phoenix
FMP-6
Drainage system maintenance
Ongoing Capability. Continuous activity.
2016 Phoenix
FMP-7
Drainage system improvements
In Progress. The Street Transportation
Department provides annual funding to
perform local drainage studies and
seek flood hazard mitigation projects in
partnership with the Flood Control
District of Maricopa County. The City
performs approximately one to two
projects per year addressing local
drainage hazards with includes cost
participation from the Flood Control
District of Maricopa County.
2016 Phoenix
FMP-8
Property protection funding
Ongoing Capability. The Street
Transportation Department provides
annual funding to perform local
drainage studies and seek flood hazard
mitigation projects in partnership with
the Flood Control District of Maricopa
County. The City performs
approximately one to two projects per
year addressing local drainage hazards
with includes cost participation from
7 | Step 7: Review Possible Activities
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Action
Description
Status Update
the Flood Control District of Maricopa
County.
2016 Phoenix
FMP-9
Regulatory review
Ongoing Capability. CRS Recertification
Visit annually completed. Community
Assistance Visit by Arizona Department
of Water Resources completed in June
2023.
2016 Phoenix
FMP-10
NFIP administration
Ongoing Capability. NFIP
administration completed Floodplain
Management, Office of the City
Engineer.
2016 Phoenix
FMP-11
Certified Floodplain Managers
Completed. Several staff are Certified
Floodplain Managers (CFMs).
2016 Phoenix
FMP-12
Flood response plan
Ongoing Capability. Emergency plans
are maintained and updated annually.
2016 Phoenix
FMP-13
Newspaper notifications
Ongoing Capability. Continuous activity.
2016 Phoenix
FMP-14
City Notes articles
Ongoing Capability. Continuous activity.
2016 Phoenix
FMP-15
City Website
Ongoing Capability. Updated as
necessary.
2016 Phoenix
FMP-16
Technical References
Ongoing Capability. Annual CRS
Recertification and Community
Assistance Visits by Arizona
Department of Water Resources as
needed.
2016 Phoenix
FMP-17
Public information projects
Ongoing Capability. Continuous
activities.
2016 Phoenix
FMP-18
Public information messages
Ongoing Capability. Continuous
activities.
2021 Maricopa
MJHMP-1
Review building permits for compliance with
Floodplain Ordinance and NFIP regulations.
Ongoing Capability. Continuous activity.
2021 Maricopa
MJHMP-2
Continue to include in the General Plan policies that
protect the natural flow regime of washes,
designate areas for Open Space and Preserves, and
when fiscally possible support the use of green
stormwater infrastructure/ low impact development
to address multiple risks.
Ongoing Capability. Continuous activity.
2021 Maricopa
MJHMP-3
Storm Drain CIP Program. Construct drainage
facilities to mitigate flooding hazard to residents of
the city.
Ongoing Capability. The Street
Transportation Department provides
annual funding to perform local
drainage studies and seek flood hazard
mitigation projects in partnership with
the Flood Control District of Maricopa
County. The City performs
approximately one to two projects per
year addressing local drainage hazards
with includes cost participation from
the Flood Control District of Maricopa
County.
7 | Step 7: Review Possible Activities
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Action
Description
Status Update
2021 Maricopa
MJHMP-4
Coordinate review and approval of development
projects located within flood hazard areas with PDD
and Floodplain Management.
Ongoing Capability. Continuous activity.
2021 Maricopa
MJHMP-8
Revise and ratify the General Plan every ten years.
Ongoing Capability. Continuous activity.
2021 Maricopa
MJHMP-9
Update and adopt a revised building code.
Ongoing Capability (evaluated every 5
years)
2021 Maricopa
MJHMP-10
Continue to ensure zoning stipulations are met
before construction permits are issued, and zoning
is compatible with the zoning ordinance.
Ongoing Capability. Continuous activity.
2021 Maricopa
MJHMP-11
Dam/Levee Safety Program – Operate and Maintain
Dams/Levees to mitigate flooding hazard to the
residents of the city.
Ongoing Capability. Continuous activity.
2021 Maricopa
MJHMP-12
Continue to provide links on the Phoenix.gov/Office
of Emergency Management website to sources of
hazard mitigation educational materials such as
FEMA.gov and Ready.gov
Ongoing Capability. Continuous activity.
2021 Maricopa
MJHMP-16
Design and construct Rio Salado Oeste in Salt River
(19th Ave-83rd Ave), including low flow channel
improvements and riparian/xeri-riparian vegetation
to improve flow conveyance and increase native
vegetation/ habitat.
In Progress. Existing conditions
assessment and public outreach
underway.
2021 Maricopa
MJHMP-20
Implement a notification system for Downtown
Phoenix businesses to raise hazard awareness and
provide advanced warning of potential threats in the
area.
Completed. Emergency warnings are
delivered through the Community
Emergency Notification System
(CENS), Wireless Emergency Alerts
(WEA), the Emergency Alert System
(EAS) via radio and TV, and the Outdoor
Warning Siren System.
Actions that were in progress or had no progress were evaluated to determine if they should be
discontinued or included in the 2025 FMP. Reasons for discontinuing an action include that the action has
been evaluated as being duplicative, impractical, unfeasible, or undesirable, or if the problem that the action
was originally developed for is no longer present. Actions that were identified for inclusion in the updated
mitigation strategy received additional evaluation to determine if the action should be revised to reflect any
new information obtained as part of the plan update process (for example, changes in risk, capabilities,
lead agency, or available funding sources).
7.2
CATALOG OF MITIGATION ALTERNATIVES
The planning team used findings of public outreach efforts, the risk assessment results, and the actions
identified in the 2016 FMP, 2021 Maricopa County MJHMP, and the 2025 Pima County FMP to finalize the
catalog for the 2025 FMP. The resulting catalog includes alternatives that are categorized by what the
alternative would do:
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•
Manipulate the flooding hazard
•
Reduce exposure to the flooding hazard
•
Reduce vulnerability to the flooding hazard
•
Increase the ability to respond to or be prepared for the flooding hazard.
The catalog includes actions to mitigate current risk from the flood hazards assessed by this plan as well
as actions to help reduce risk from changes in the impacts of these hazards resulting from climate change.
It provides a baseline of mitigation alternatives that are backed by a planning process, are consistent with
the established goals and objectives, and are generally within the capabilities of the City to implement.
Some of its alternatives may not be feasible based on the selection criteria identified for this plan. Actions
were selected based on an analysis of the City’s ability to implement the action and general feasibility.
Actions from the catalog that are not included in the action plan were not selected for one or more of the
following reasons:
•
The action is not feasible.
•
The action is already being implemented.
•
The City lacks the current capability to implement the action.
•
There is apparently a more cost-effective alternative.
•
The action does not have public or political support.
7.3
PREVENTIVE ACTIVITIES
The City has several preventive activities in place. These activities include, but are not limited to, zoning,
stormwater management design regulations, building codes, subdivision ordinances, mountain preserves,
and a general plan. The documents all work together to provide for safe development within the City.
These tools can reduce future flood impacts through strict review procedures for design plans and in-depth
inspection during construction. This requires multiple City departments working together to help develop
safely. The current regulations meet or exceed the minimum requirements of the NFIP and support
effective development within the City. The City plans support a long-term vision for where the City needs
to go and what needs to be done. The City General Plan 2025 prioritizes a more connected City and through
the connectivity the City expects to see prosperity, increase in health and well-being, and a reduction in
environmental impacts.
The City is continually seeking ways to improve upon their regulations while still allowing development to
occur. The City should seek to update building codes on a regular interval to keep them current within the
last 5-years. Currently, outside of the building codes. the City does not have any pressing needs to revise
or adopt new regulations.
7.4
REGULATORY STANDARDS FUTURE OUTLOOK
The City’s regulatory standards are sufficient to address current and future needs. As updates are made
to precipitation data in the area, the requirements will increase based on the current equations and
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analyses needed within the City’s design guidelines and standards. In addition, the City often references
the Flood Control District of Maricopa County guidelines that are updated as needed to meet the needs of
the County.
Activities within this FMP will support ongoing reviews of the regulatory standards for updates.
7.5
PROPERTY PROTECTION ACTIVITIES
The City provides technical support to those inquiring about floodplain related issues at their properties.
The City does not have a history with acquisition of properties or retrofitting. However, the City provides
support in where to find resources for flood insurance. This support can help direct a property owner into
getting a policy to protect their assets.
Activities within this FMP will support ongoing public outreach and technical support to residents when
needed for flood insurance and other flood related needs.
7.6
PLAN REVIEW ACTIVITIES
The City’s General Plan 2025 wants to address the connectivity of the City not only from a transportation
aspect but also with natural open spaces and corridors. Keeping these areas open and natural not only
helps with the natural floodplain functions and reductions of flood risks, but they also allow for connectivity.
Additionally, protecting the mountain preserves from development will help reduce future increased flood
risks by preserving as much natural open space as possible.
Activities within this FMP will support preserving open space within the City and promoting keeping
drainage corridors and washes in their natural state as development occurs in the area.
7.7
EMERGENCY SERVICES ACTIVITIES
The City conducts annual exercises to determine the readiness of the different departments in the event
of a flood emergency. The City’s dams group utilizes the emergency action plans for the dams to enact
these exercises that involves people from different departments of the City and external stakeholders.
These exercises will continue on an annual basis with updates to the emergency action plans completed
on an as needed basis.
Activities within this FMP will support emergency services through annual exercises and plans. These
plans will guide the City staff in the event of an emergency with what needs to be done and who needs to
be involved in the process. Also, the City will work in partnership with the Flood Control District of Maricopa
County to place flood fight (sand and sandbags) in strategic locations around the City.
7.8
STRUCTURAL PROJECT ACTIVITIES
The City has several ongoing structural projects to reduce flooding impacts on its residents. Activities
within the FMP will support the completion of these projects and the long-term maintenance required to
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keep them functioning as designed. These projects include storm drain rehabilitation, channels, dam and
levee maintenance, and new storm drains and basins.
7.9
PUBLIC OUTREACH ACTIVITIES
Public outreach is vital to any City project. Getting community support or helping direct them to the
resources they need is critical. The City does outreach as part of each project they do in order to inform
residents and property owners of a study or design that is being conducted to get input or when a project
is about to go into construction.
Activities within this FMP will help provide more information to the public on what they can do to reduce
their flood risks and also promote what the City is doing and what resources the City has to help.
7.10
FUNDING CAPABILITY
The City utilizes a variety of sources to fund different projects. A detailed discussion is provided within
Section 4.1.4, and these include the City’s general fund, state and federal grants, and partnerships with the
Flood Control District of Maricopa County. Several activities discussed will involve staff time alone which
will reduce the impact to get the activity completed.
8 | Step 8: Draft an Action Plan
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
8-1
8
STEP 8: DRAFT AN ACTION PLAN
8.1
DEVELOPING MITIGATION ACTIONS
The FMP Committee reviewed the results of the risk and capability assessments; the City of Phoenix’s
mitigation strategy in the 2016 City of Phoenix Floodplain Management Plan and the 2021 Maricopa
County Multi-Jurisdictional Hazard Mitigation Plan; the 2025 FMP goals; and the catalog of mitigation
alternatives. and selected actions to be included in the 2025 FMP Action Plan.
8.2
MITIGATION ACTION CATEGORIZATION
Mitigation actions were selected to include a variety of action types. The following action types were
included.
8.2.1
Prevention
Preventive activities are intended to keep hazard problems from getting worse and are typically
administered through programs or regulatory actions that influence the way land is developed and assets
are built. In the context of this plan, prevention measures also include security initiatives. Prevention
measures are particularly effective in reducing a jurisdiction’s future vulnerability, especially in areas where
development has not occurred or capital improvements have not been substantial. Examples of preventive
activities include:
•
Planning and zoning
•
Open space preservation
•
Floodplain regulations
•
Stormwater management regulations
•
Drainage system maintenance
•
Capital improvement programs
•
Riverine setbacks
8.2.2
Property Protection
Property protection activities involve the modification of existing buildings, assets, and structures to help
them better withstand the forces of a hazard or the removal of the structures from hazardous locations.
Examples include:
•
Acquisition
•
Relocation
•
Asset and building elevation
•
Structural retrofitting
8 | Step 8: Draft an Action Plan
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
8-1
8.2.3
Natural Resource Protection
Natural resource protection activities reduce the impact of natural hazards by preserving or restoring
natural areas and their protective functions. Such areas include floodplains, wetlands, and steep slopes:
•
Floodplain protection
•
Watershed management
•
Riparian buffers
•
Habitat preservation
•
Erosion and sediment control
•
Wetland preservation and restoration
•
Slope stabilization
•
Forest and vegetation management
•
Green stormwater infrastructure
8.2.4
Emergency Services
Although not typically considered a “mitigation” technique, emergency service activities do minimize the
impact of a hazard event on people and property. These commonly are actions taken immediately prior to,
during, or in response to a hazard event. Examples include:
•
Warning and communication systems
•
Evacuation planning and management
•
Emergency response training and exercises
•
Sandbagging for flood protection
8.2.5
Structural Projects
Structural mitigation activities are intended to lessen the impact of a hazard by modifying the
environmental natural progression of the hazard event through construction. They are usually designed by
engineers and managed or maintained by jurisdiction staff. Examples include:
•
Reservoirs
•
Dams, levees, dikes, and floodwalls
•
Diversions, detention, retention
•
Channel modification
•
Stormwater infrastructure expansion
•
Water and sewer infrastructure improvements
8.2.6
Public Information
Public education and awareness activities are used to advise residents, elected officials, business owners,
potential property buyers, and visitors about hazards, hazardous areas, and mitigation techniques they can
use to protect themselves and their property. Examples of measures to educate and inform the public
include:
8 | Step 8: Draft an Action Plan
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
8-2
•
Outreach projects
•
Speaker series and demonstration events
•
Hazard map information
•
Library materials
•
School-age educational programs
•
Social media campaigns
8.3
MITIGATION ACTIONS SELECTED FOR THE ACTION PLAN
The 2025 FMP Action Plan includes 34 unique flood mitigation actions identified for implementation by
the FMP Committee. Table 8-1 provides the following information for each action in the 2025 FMP Action
Plan:
•
Action Number: An identification number for future tracking of progress.
•
Description: A short discussion of the details of the action.
•
Responsible Party: The agencies responsible for overseeing implementation of the action.
•
Funding Source: Potential sources of funding to conduct/implement each action.
•
Timeline: A proposed timeline for the completion of the action.
•
Category: Categorization of the action type.
•
Priority: Actions were prioritized according to funding availability, the immediacy of the need for
each project, and informal review of benefits versus costs.
Actions have been selected to support each of the five goals for the 2025 FMP.
8 | Step 8: Draft an Action Plan
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
8-3
Table 8-1. 2025 Phoenix FMP Action Plan
Action
Number
Description
Responsible Party
Funding
Source
Timeline
Category
Priority
FMP Goal 1: Educate public, policy makers, and City leaders on stormwater and floodplain management and risks
2025
PHOENIX
FMP-1
Create an annual stormwater and floodplain
management workshop for City leaders,
Councilmembers, and Neighborhood Services
to help with stormwater and floodplain
education and outreach held prior to
presentation at Council Meeting.
Floodplain/City
Engineer
Staff Time
Ongoing
Public Information
Medium
2025
PHOENIX
FMP-2
Present annually at a City of Phoenix Council
Meeting on state of City’s stormwater and
floodplain program.
Floodplain/City
Engineer
Staff Time
Ongoing
Public Information
Low
2025
PHOENIX
FMP-3
Develop flyers, CRS Annual Outreach Letter,
and ongoing updates to the City's Floodplain
webpage for use by the public, City leaders,
policy makers, and the City’s Neighborhood
Services department.
Floodplain/City
Engineer, Public
Information Office
Staff Time
Ongoing
Public Information
Low
2025
PHOENIX
FMP-4
Post at least five times per year on
stormwater, floodplain, or flood insurance
related topics on the City’s social media
platforms.
Floodplain/City
Engineer, Public
Information Office
Staff Time
Ongoing
Public Information
Low
2025
PHOENIX
FMP-5
Include stormwater section bi-annually within
the City’s water bill for stormwater and
floodplain outreach and education purposes.
Floodplain/City
Engineer, Public
Information Office,
Water Services
Department
Staff Time
Ongoing
Public Information
Low
2025
PHOENIX
FMP-6
Attend/Present at four neighborhood
associations meetings, festivals, or home &
garden shows per year to provide information
to the public on recent, current, and future
stormwater and floodplain projects and the
importance of flood insurance if property in
floodplain.
Floodplain/City
Engineer, Public
Information Office
Staff Time
Ongoing
Property Protection,
Public Information
Low
8 | Step 8: Draft an Action Plan
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
8-4
Action
Number
Description
Responsible Party
Funding
Source
Timeline
Category
Priority
2025
PHOENIX
FMP-7
Place signage at City dams to educate the
public of the presence of the structure, the
need for the structure, and risks.
Streets, Public
Information Office,
Parks
General
Fund
2027
Public Information
Low
2025
PHOENIX
FMP-8
Provide annual outreach to repetitive loss
areas.
Floodplain/City
Engineer, Public
Information Office
General
Fund
Ongoing
Public Information
High
FMP Goal 2: Coordinate with other jurisdictions and agencies to mitigate flooding hazards and improve emergency response
2025
PHOENIX
FMP-9
Continue to participate in local or independent
annual dam safety and flood response
exercises and invite other agencies to
participate.
Floodplain/City
Engineer, Streets,
Emergency
Management,
Public Information
Office
General
Fund
Ongoing
Preventative,
Emergency
Services
High
2025
PHOENIX
FMP-10
Continue to coordinate with other local and
regional agencies for flood warnings and
emergency response.
Floodplain/City
Engineer, Streets,
Emergency
Management,
Public Information
Office
General
Fund
Ongoing
Preventative,
Emergency
Services
Medium
2025
PHOENIX
FMP-11
Have at least one City staff attend a FEMA
training/workshop annually for emergency
response or floodplain management.
Floodplain/City
Engineer
Staff Time
Ongoing
Emergency
Services
Medium
2025
PHOENIX
FMP-12
Coordinate with Arizona Department of Water
Resources to establish a network of
Continuously Operating Reference Stations
(CORS) throughout the City to provide
overlapping coverage to support increased
detail in surveys for development and public
infrastructure projects.
Floodplain/City
Engineer, Streets
General
Fund
2030
Preventative,
Emergency
Services
Low
2025
PHOENIX
FMP-13
Develop a substantial damage response plan
and coordinate with outside groups and
agencies to ensure NFIP requirements are
met following disaster events.
Floodplain/City
Engineer, Planning
and Development,
Public Information
FEMA
FMA, Staff
Time
2030
Emergency
Services
Medium
8 | Step 8: Draft an Action Plan
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
8-5
Action
Number
Description
Responsible Party
Funding
Source
Timeline
Category
Priority
Office, Emergency
Management
FMP Goal 3: Reduce the danger of flood hazards to people, property, critical infrastructure/facilities, and natural resources
2025
PHOENIX
FMP-14
Hold an annual in person meeting, and record
for a webcast, to provide recommendations
for proper vegetation maintenance and flood
preparedness.
Floodplain/City
Engineer, Public
Information Office
Staff Time
Ongoing
Preventative,
Natural Resource
Protection, Public
Information
Low
2025
PHOENIX
FMP-15
Evaluate the requirement for new
developments to preserve natural drainage
corridors and implement Green Stormwater
Infrastructure and Low Impact Development.
Floodplain/City
Engineer, Planning
and Development
Staff Time
2030
Natural Resource
Protection
Medium
2025
PHOENIX
FMP-16
Complete major projects within the current
Capital Improvement Program – Paradise
Ridge Drainage Improvements; Drainage
Improvements: 20th Street between
Winchcomb Drive and 19th Way; Storm Drain
Replacement Study; Laveen Flood Mitigation;
Hohokam Drainage Program; 3rd Street and
Thomas; 12 ARPA Projects; and Storm Drain
Asset Management and Replacement
Program
Floodplain/City
Engineer, Streets
General
Fund,
General
Obligation
Bond,
Federal
Grants,
Partner
Funding
2030
Structural Projects
High
2025
PHOENIX
FMP-17
Identify and map critical infrastructure and
facilities within the City of Phoenix (for
Internal City Use Only).
Emergency
Management
Staff Time
2030
Emergency
Services
Medium
2025
PHOENIX
FMP-18
Evaluate flood risks for critical infrastructure
and facilities (for Internal City Use Only).
Floodplain/City
Engineer,
Emergency
Management
Staff Time
2030
Emergency
Services
Medium
2025
PHOENIX
FMP-19
Provide flood fight materials (sand and bags)
at/near critical infrastructure and facilities
based on flood risk (for Internal City Use Only).
Floodplain/City
Engineer, Streets,
Emergency
Management
Staff Time
2030
Emergency
Services
Medium
8 | Step 8: Draft an Action Plan
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
8-6
Action
Number
Description
Responsible Party
Funding
Source
Timeline
Category
Priority
2025
PHOENIX
FMP-20
Annually update database of critical
infrastructure and facilities (for Internal City
Use Only).
Emergency
Management
Staff Time
Ongoing
Emergency
Services
Medium
2025
PHOENIX
FMP-21
Establish or Update Emergency Action Plans
to address flood response scenarios for City-
owned critical infrastructure and facilities (for
Internal City Use Only).
Floodplain/City
Engineer, Streets,
Water Services
Department,
Emergency
Management
General
Fund
Ongoing
Emergency
Services
High
2025
PHOENIX
FMP-22
Update Emergency Action Plans notification
charts annually for the City’s flood control
dams.
Floodplain/City
Engineer, Streets,
Water Services
Department,
Emergency
Management
General
Fund
Ongoing
Emergency
Services
High
2025
PHOENIX
FMP-23
Submit a Letter of Map Revision to FEMA to
have over 2,000 acres of land taken out of the
100-year floodplain as a result of the recently
completed Rawhide wash channelization
project in northeast Phoenix.
Floodplain/City
Engineer, Planning
and Development
Staff Time
2027
Preventative
High
FMP Goal 4: Enhance proactive maintenance and preventive measures for stormwater infrastructure
2025
PHOENIX
FMP-24
Documentation of maintenance occurring at
problematic areas throughout the year,
including cost to complete each occurrence.
Floodplain/City
Engineer, Streets,
Public Information
Office
Staff Time
2026
Preventative
Medium
2025
PHOENIX
FMP-25
Continue monitoring of self-audit
maintenance for drywells installed after 2022
when guidance was established.
Environmental
Staff Time
Ongoing
Preventative,
Property Protection
Medium
2025
PHOENIX
FMP-26
Publicize City’s 311 App and Webpage for
reporting maintenance issues.
Floodplain/City
Engineer, Streets,
Public Information
Office
Staff Time
2026
Public Information
Medium
8 | Step 8: Draft an Action Plan
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
8-7
Action
Number
Description
Responsible Party
Funding
Source
Timeline
Category
Priority
2025
PHOENIX
FMP-27
Publicize a summary of the City’s stormwater
maintenance work completed each year
(webpage, social media post, and/or water
bill).
Floodplain/City
Engineer, Streets
Staff Time
Ongoing
Preventative, Public
Information
Low
2025
PHOENIX
FMP-28
Continue to evaluate on an annual basis the
current stormwater and floodplain
requirements, zoning and subdivision
ordinances, guidelines, regulations, codes,
design manuals, and land use plan for
updates.
Floodplain/City
Engineer, Streets,
Planning and
Development
Staff Time
Ongoing
Preventative
Medium
2025
PHOENIX
FMP-29
Evaluate and update Building Codes on a
routine basis (at least every 5 years).
Planning and
Development
Staff Time
2030
Preventative
Medium
2025
PHOENIX
FMP-30
Develop a publicly facing vegetation
maintenance guide for private use for wash
corridors, storm drain inlets and outlets, and
stormwater storage basins and provide at
outreach events and on City's website.
Floodplain/City
Engineer
Staff Time
2030
Property Protection,
Natural Resource
Protection, Public
Information
Low
2025
PHOENIX
FMP-31
Evaluate City-owned storm drain
infrastructure for maintenance and
rehabilitation needs.
Floodplain/City
Engineer, Streets
General
Obligation
Bond
2030
Preventative,
Structural Projects
High
FMP Goal 5: Utilize public funding in the most effective manner for stormwater and floodplain management
2025
PHOENIX
FMP-32
Utilize General Obligation Bond funding to
mitigate flooding risks.
Floodplain/City
Engineer, Streets
General
Obligation
Bond
2030
Structural Projects
High
2025
PHOENIX
FMP-33
Seek opportunity to apply for grants through
state and federal agencies to reduce the
burden on the City for stormwater and
floodplain management projects.
Floodplain/City
Engineer
Staff Time
Ongoing
Structural Projects
High
2025
PHOENIX
FMP-34
Continue partnership with the Flood Control
District of Maricopa County and the Small
Projects Assistance Program.
Floodplain/City
Engineer, Streets
Staff Time
Ongoing
Structural Projects
Medium
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
9-1
Step 9: Adopt the Plan
9
STEP 9: ADOPT THE PLAN
This chapter documents formal adoption of the 2025 FMP by the Phoenix City Council (CRS Step 9). A
copy of the adoption resolution is provided in Figure 9-1.
Figure 9-1 City of Phoenix 2025 Floodplain Management Plan Adoption
WILL BE INCLUDED IN THE FINAL VERSION
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
10-1
Step 10: Implement, Evaluate, Revise
10 | Step 10: Implement, Evaluate, Revise
10
STEP 10: IMPLEMENT, EVALUATE, REVISE
This chapter presents a plan implementation and plan maintenance process (CRS Step 10) that includes
the following:
•
A process to incorporate the FMP into other planning mechanisms
•
A process for implementing the FMP actions
•
A method for monitoring and evaluating the floodplain management plan over a 5-year cycle
by the FMP Committee
•
A process for the public to continue to participate in the plan maintenance process
•
A process for the City of Phoenix to update the FMP
By establishing a plan maintenance strategy, the City of Phoenix can ensure that the 2025 FMP remains
an active and relevant document. It includes a schedule for monitoring and evaluating the 2025 FMP
annually and producing an updated plan every five years to meet CRS requirements. The strategy also
describes how public participation will be integrated throughout the plan maintenance and implementation
process. It explains how the mitigation strategies outlined in the 2025 FMP will be incorporated into
existing planning mechanisms and programs, such as comprehensive land-use planning processes,
capital improvement planning, hazard mitigation planning, and building code enforcement and
implementation. The 2025 FMP’s format allows sections to be reviewed and updated when new data
becomes available, resulting in a plan that will remain current and relevant.
10.1
INCORPORATION INTO OTHER PLANNING MECHANISMS
The City of Phoenix will incorporate the 2025 FMP into relevant decision-making processes, plans, or
mechanisms, where feasible. The following planning processes and programs are to be coordinated with
the recommendations of the 2025 FMP:
•
Local hazard mitigation plan
•
Emergency response plan
•
Capital improvement programs
•
Municipal codes
•
Community design guidelines
•
Water-efficient landscape design guidelines
•
Stormwater management programs
•
Water system vulnerability assessments
Some action items do not need to be implemented through regulation. Instead, these items can be
implemented through the creation of new educational programs, continued interagency coordination, or
improved public participation. As information becomes available from other planning mechanisms that
can enhance the 2025 FMP, that information will be incorporated via the update process.
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
10-2
Step 10: Implement, Evaluate, Revise
10 | Step 10: Implement, Evaluate, Revise
10.2
IMPLEMENTING THE 2025 FMP THROUGH EXISTING PROGRAMS
To successfully reduce future losses, implementing the actions within this plan is highly recommended.
The City of Phoenix involved a wide range of staff in the plan development process and many departments,
divisions, or other partners participating in the 2025 FMP are responsible for implementing specific
mitigation actions identified by each jurisdiction. Every proposed action listed in the mitigation action plan
is assigned to a specific “lead” department or partner in order to assign responsibility and accountability
and increase the likelihood of implementation.
In addition to the assignment of a local lead department or partner, an implementation time period or a
specific implementation date has been assigned in order to assess whether actions are being implemented
in a timely fashion. The City of Phoenix will seek outside funding sources to implement mitigation projects
in both the pre-disaster and post-disaster environments. When applicable, specific potential funding
sources have been identified for proposed actions listed in the mitigation action plan.
The Office of the City Engineer will have lead responsibility for overseeing the 2025 FMP implementation
and maintenance strategy. Implementation and evaluation will be a shared responsibility among all
agencies identified as lead agencies in the mitigation action plan.
10.3
MONITORING AND EVALUATING THE 2025 FMP
The FMP Committee oversaw the development of the 2025 FMP and made recommendations on key
elements of the plan, including the maintenance strategy. It was the FMP Committee’s position that an
oversight committee with representation similar to that of the FMP Committee should have an active role
in the 2025 FMP maintenance strategy. Therefore, it is recommended that a FMP Committee remain a
viable body involved in key elements of the plan maintenance strategy. The new FMP Committee should
include representation from local stakeholders.
The FMP Committee will meet once annually during the five-year performance period of this Plan and
provide input to the Office of the City Engineer on possible enhancements to be considered at the next
update. This frequency of meeting will also assist in implementation, as meetings will be coordinated with
the strategic planning process. Future plan updates will be overseen by a FMP Committee similar to the
one that participated in development of the 2025 FMP, so keeping an interim FMP Committee intact will
provide a head start on future updates.
The minimum task of the ongoing annual FMP Committee meeting will be the evaluation of the progress
of the action plan during a 12-month performance period. This review will include the following:
•
Summary of any flood hazard events that occurred during the performance period and the impact
these events had on the City of Phoenix
•
Review of mitigation success stories
•
Review of continuing public involvement
•
Brief discussion about why targeted strategies were not completed
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
10-3
Step 10: Implement, Evaluate, Revise
10 | Step 10: Implement, Evaluate, Revise
•
Re-evaluation of the action plan to determine if the timeline for identified projects needs to be
amended (such as changing a long-term project to a short-term one because of new funding)
•
Recommendations for new projects
•
Changes in or potential for new funding options (grant opportunities)
•
Impact of any other planning programs or actions that involve floodplain management.
A template for preparing a progress report is provided in Appendix E. The FMP Committee will provide
feedback to the City of Phoenix Floodplain Management Department on items included in the template.
The City of Phoenix Floodplain Management Department will then prepare a formal annual report on the
progress of the plan. This report should be used as follows:
•
Posted on the Floodplain Management web page
•
Provided to the local media through a press release
•
Provided to the City Council to inform them of the progress of mitigation actions implemented
during the reporting period
•
Provided as part of the CRS annual re-certification package. The CRS requires an annual
recertification to be submitted every calendar year for which the community has not received a
formal audit.
10.4
ONGOING PUBLIC INVOLVEMENT
Public participation is an integral component to the floodplain management planning process and will
continue to be essential as this plan evolves over time. Public involvement procedures were reviewed as
part of the 2025 FMP development process. The public will continue to be apprised of the plan’s progress
through the floodplain management plan website and by providing copies of annual progress reports to
the media
(https://www.phoenix.gov/administration/departments/city-engineer/floodplain-management.html). The
website will not only house the final plan, but it will also become the one-stop shop for information
regarding the plan and plan implementation. Copies of the plan will also be distributed to the City of
Phoenix library system. Upon initiation of future update processes, a new public involvement strategy will
be initiated based on guidance from a new FMP Committee. This strategy will be based on the needs and
capabilities of City of Phoenix at the time of the update. At a minimum, this strategy will include the use of
local media outlets.
10.5
UPDATING THE PLAN
The City of Phoenix intends to update the 2025 FMP on a 5-year cycle from the date of its adoption (CRS
Step 10). This cycle may be accelerated to less than 5 years based on the following triggers:
•
A federal flood-related disaster declaration that impacts the City of Phoenix
•
A flood event that causes loss of life
•
A comprehensive update of the City of Phoenix general plan.
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
10-4
Step 10: Implement, Evaluate, Revise
10 | Step 10: Implement, Evaluate, Revise
It will not be the intent of future updates to develop a completely new floodplain management plan. The
update will, at a minimum, include the following elements:
•
The update process will be convened through a FMP Committee.
•
The hazard risk assessment will be reviewed and, if necessary, updated using best available
information and technologies.
•
The action plan will be reviewed and revised to account for any actions completed, dropped, or
changed and to account for changes in the risk assessment or new policies identified under other
planning mechanisms (such as the general plan).
•
The draft update will be sent to appropriate agencies and organizations for comment.
•
The public will be given an opportunity to comment on the update prior to adoption.
•
The City of Phoenix City Council and Mayor will adopt the updated plan.
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
Terminology-1
Terminology
TERMINOLOGY
ACRONYMS
ACE—Annual Chance of Exceedance
ADA—Americans with Disabilities Act
ADEQ—Arizona Department of Environmental Quality
ADMPU—Area Drainage master Plan Update
ADOT—Arizona Department of Transportation
ADWR—Arizona Department of Water Resources
ARPA—American Rescue Plan Act
ARS—Arizona Revised Statute
ASLD—Arizona State Land Department
AZ DEMA—Arizona Department of Emergency and Military Affairs
AZSTORM—AZ Stormwater Outreach for Regional Municipalities
BCEGs—Building Code Effectiveness Grading Schedule
BFE—Base Flood Elevation
BUILD— Better Utilizing Investments to Leverage Development
CAP—Community Assistance Program
CAC—Community Assistance Contact
CAV—Community Assistance Visit
CAZCA—Central Arizona Conservation Alliance
CDBG—Community Development Grant Program
CDC/ARSDR—Centers for Disease Control and Prevention and Agency for Toxic Substances and Disease
Registry
CENS—Community Emergency Notification System
CFM—Certified Floodplain Manager
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
Terminology-2
Terminology
CFR—Code of Federal Regulations
CIAO—Critical Infrastructure Assurance Office
COOP—Continuity of Operations Plan
CRS—Community Rating System
CWA—Clean Water Act
DFE—Design Flood Elevation
DMA— Disaster Mitigation Act
EAP—Emergency Action Plan
EAS—Emergency Alert System
EMPG—Emergency Management Performance Grants
ESA—Endangered Species Act
EWP—Emergency Watershed Program
FCDMC—Flood Control District of Maricopa County
FEMA—Federal Emergency Management Agency
FERC—Federal Energy Regulatory Commission
FHBM—Flood Hazard Boundary Map
FHWA—Federal Highway Administration
FIRM—Flood Insurance Rate Map
FMA—Flood Mitigation Assistance
FMP—Floodplain Management Plan
FPA—Floodplain Administrator
FPMS—Flood Plain Management Services Program
FTA—Federal Transit Authority
FY—Fiscal Year
GI—General Investigation
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
Terminology-3
Terminology
GIS—Geographic Information System
HHPD—High Hazard Potential Dam
HIFLD—Homeland Infrastructure Foundation-Level Data
HMA—Hazard Mitigation Assistance
HMGP—Hazard Mitigation Grant Program
HSGP—Homeland Security Grant Program
HUD—U.S. Department of Housing and Urban Development
IA—Individual Assistance
ICW—Inspection of Completed Works Program
IDDE—Illicit Discharge Detection and Elimination
IIJA—Infrastructure Investment and Jobs Act
ISO—Insurance Services Office
LPDM—Legislative Pre-Disaster Mitigation
LSAC—Levee Safety Action Classification
MAG—Maricopa Association of Governments
MCCOAD—Maricopa County Community Organizations Active in Disaster
MCDEM—Maricopa County Department of Emergency Management
MCDOT—Maricopa Department of Transportation
MC-LEPC—Maricopa County Local Emergency Planning Committee
MJHMP—Multi-jurisdictional Hazard Mitigation Plan
NCA—National Climate Assessment
NCEI—National Centers for Environmental Information
NDSP—National Dam Safety Program
NFIP—National Flood Insurance Program
NFPP—National Fish Passage Program
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
Terminology-4
Terminology
NLCS—National Committee on Levee Safety
NLSP—National Levee Safety Program
NID—National Inventory of Dams
NIMS—National Incident Management System
NOAA—National Oceanic and Atmospheric Administration
NPDES—National Pollutant Discharge Elimination System
NRCS—National Resources Conservation Service
NRI—National Risk Index
NWS—National Weather Service
OEP—Phoenix Office of Environmental Program
OHSEM—Office of Homeland Security and Emergency Management
PA—Public Assistance
PAS—Planning Assistance to States
PIT—Point-in-Time
PUD—Planned Unit Development
RAISE—Rebuilding American Infrastructure with Sustainability and Equity
RIP—Rehabilitation and Inspection Program
RL–Repetitive Loss
SBA—Small Business Administration
SEOC—State Emergency Operations Center
SERP—State Emergency Response and Recovery Plan
SFHA—Special Flood Hazard Area
SPAP—Small Project Assistance Program
SPC—Storm Prediction Center
SRL—Severe Repetitive Loss
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
Terminology-5
Terminology
STORM RLF—Safeguarding Tomorrow through Ongoing Risk Mitigation Revolving Loan Fund
SVI—Social Vulnerability Index
SWM—Phoenix Stormwater Management Section
SWMP—Stormwater Management Plan
THIRA—Threat & Hazard Identification & Risk Assessment
TIGER—Transportation Investment Generating Economic Recovery
TOC—Tactical Operations Center
USACE—U.S. Army Corps of Engineers
USDA—U.S. Department of Agriculture
USDHSES—U.S. Department of Health and Human Services
USDOT—U.S. Department of Transportation
USEPA—U.S. Environmental Protection Agency
USFWS—U.S. Fish and Wildlife Service
USGS—U.S. Geological Survey
WFPO—Watershed and Flood Prevention Operations Program
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
Terminology-6
Terminology
DEFINITIONS
100-Year Flood: The flood that has a 1 percent chance of being equaled or exceeded in any given year. The
100-year flood does not necessarily occur once every 100 years. It is possible for a 100-year flood to occur
more than once in a relatively short period of time.
Acre-Foot: The amount of water it takes to cover 1 acre to a depth of 1 foot. This measure is used to
describe the quantity of storage in a water reservoir. An acre-foot is a unit of volume. One acre foot equals
7,758 barrels; 325,829 gallons; or 43,560 cubic feet. An average household of four will use approximately
1 acre-foot of water per year.
Base Flood: Another term for the 100-year flood—the flood having a 1 percent chance of being equaled or
exceeded in any given year. The base flood is used as a reference flood level to ensure that all properties
subject to the National Flood Insurance Program are protected to the same degree against flooding.
Benefit/Cost Analysis: A systematic, quantitative method of comparing projected benefits to projected
costs of a project or policy. It is used as a measure of cost effectiveness. For the purposes of benefit-cost
analysis of proposed mitigation actions, benefits are limited to specific, measurable, risk reduction factors,
including reduction in expected property losses (buildings, contents, and functions) and protection of
human life.
Capability Assessment: A description and analysis of a community’s current capacity to address threats
associated with flooding. The assessment includes two components: an inventory of an agency’s mission,
programs, and policies, and an analysis of its capacity to carry them out. A capability assessment is an
integral part of the planning process in which a community’s actions to reduce losses are identified,
reviewed, and analyzed, and the framework for implementation is identified.
Community Rating System (CRS): A voluntary program that provides flood insurance premium discounts
to property owners in communities that exceed the minimum requirements of the National Flood
Insurance Program and complete activities that reduce flood hazard risk.
Critical Facility: A structure or other improvement that, because of its function, size, service area, or
uniqueness, provides indispensable service that enables the continuous operation of critical business and
government functions, and is critical to human health and safety or economic security.
Drainage Basin: A basin is the area within which all surface water—whether from rainfall, snowmelt, springs
or other sources—flows to a single water body or watercourse. The boundary of a river basin is defined by
natural topography, such as hills, mountains, and ridges. Drainage basins are also referred to as
watersheds or basins.
Economically Disadvantaged Populations: Households with household incomes below a federally defined
minimum.
Exposure: The number and dollar value of assets considered to be at risk during the occurrence of a
specific hazard.
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
Terminology-7
Terminology
Federal Disaster Declaration: Declarations for events that cause more damage than state and local
governments and resources can handle without federal government assistance. Generally, no specific
dollar loss threshold has been established for such declarations. A federal disaster declaration puts into
motion long-term federal recovery programs to help disaster victims, businesses, and public entities.
Flash Flood: A flood that occurs with little or no warning when water levels rise at an extremely fast rate.
Flood Insurance Rate Map (FIRM): The official map on which the Federal Emergency Management Agency
delineates special flood hazard area for a given location.
Flood Insurance Study: A report published by the Federal Insurance and Mitigation Administration for a
community in conjunction with the community’s Flood Insurance Rate Map. The study contains such
background data as the base flood discharges and water surface elevations that were used to prepare the
FIRM. In most cases, a community FIRM with detailed mapping will have a corresponding flood insurance
study.
Floodplain: Any land area susceptible to being inundated by flood waters from any source. A flood
insurance rate map identifies most, but not necessarily all, of a community’s floodplain as the special flood
hazard area.
Floodway: Areas within a floodplain that are reserved for the purpose of conveying flood discharge without
increasing the base flood elevation more than 1 foot. Generally speaking, no development is allowed in
floodways, as any structures located there would block the flow of floodwaters.
Freeboard: The margin of safety added to the base flood elevation in the design of structures intended to
mitigate flooding.
Frequency: How often a hazard of specific magnitude, duration, and/or extent is expected to occur on
average. Statistically, a hazard with a 100-year frequency is expected to occur about once every 100 years
on average and has a 1 percent chance of occurring any given year. Frequency reliability varies depending
on the type of hazard.
Goal: A general guideline that explains what is to be achieved. Goals are usually broad-based, long-term,
policy type statements and represent global visions. Goals help define the benefits that a plan is trying to
achieve. The success of a floodplain management plan is measured by the degree to which its goals have
been met (that is, by the benefits in terms of actual floodplain management).
Geographic Information System (GIS): A computer software application that relates data regarding
physical and other features on the earth to a database for mapping and analysis.
Hazard: A source of potential danger or adverse condition that could harm people and/or cause property
damage.
Hazard Mitigation Grant Program: A FEMA program that provides grants to states, tribes, and local
governments to implement hazard mitigation actions after a major disaster declaration. The purpose of
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
Terminology-8
Terminology
the program is to reduce the loss of life and property due to disasters and to enable mitigation activities to
be implemented as a community recovers from a disaster.
Hydrology: The analysis of waters of the earth. For example, a flood discharge estimate is developed by
conducting a hydrologic study.
Intensity: The measure of the effects of a hazard.
Inventory: A list of assets identified in a study region that could be lost when a disaster occurs, and
community resources are at risk. Assets include people, buildings, transportation, and other valued
community resources.
Lifeline: A lifeline enables the continuous operation of critical government and business functions and is
essential to human health and safety or economic security.
Local Government: Any county, municipality, city, town, township, public authority, school district, special
district, intrastate district, council of governments, regional or interstate government entity, or agency or
instrumentality of a local government; any Indian tribe or authorized tribal organization, or Alaska Native
village or organization; and any rural community, unincorporated town or village, or other public entity.
Localized Flooding: Refers to smaller scale flooding that can occur anywhere in a community. This can
include flooding in zone X as depicted on the flood insurance rate map. The term is also used to refer to
shallow flooding that occurs in low lying areas after heavy rain, ponding, and localized storm water and
drainage problems anywhere in the community. In this guide, “local flooding” and “localized flooding” are
used interchangeably.
Mitigation: A preventive action that can be taken in advance of an event that will reduce or eliminate risk to
life or property.
Mitigation Actions: Mitigation actions are specific actions to achieve goals and objectives that minimize
the effects from a disaster and reduce the loss of life and property.
Objective: A short-term aim that, when combined with other objectives, forms a strategy or course of action
to meet a goal. Unlike goals, objectives are specific and measurable.
Preparedness: Actions that strengthen the capability of government, citizens, and communities to respond
to disasters.
Probability of Occurrence: A statistical measure or estimate of the likelihood that a hazard will occur. This
probability is generally based on past hazard events in the area and a forecast of events that could occur
in the future.
Repetitive Loss Property: Any NFIP-insured property that, since 1978 and regardless of any changes of
ownership during that period, has experienced:
•
Four or more paid flood losses in excess of $1,000.00; or
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
Terminology-9
Terminology
•
Two paid flood losses in excess of $1,000.00 within any 10-year period since 1978; or
•
Three or more paid losses that equal or exceed the current value of the insured property.
Risk: The estimated impact that a hazard would have on people, services, facilities, and structures in a
community. Risk measures the likelihood of a hazard occurring and resulting in an adverse condition that
causes injury or damage. Risk is often expressed in relative terms such as a high, moderate, or low
likelihood of sustaining damage above a particular threshold due to occurrence of a specific type of hazard.
Risk also can be expressed in terms of potential monetary losses associated with the intensity of the
hazard.
Risk Assessment: The process of measuring potential loss of life, personal injury, economic injury, and
property damage resulting from hazards. This process assesses the vulnerability of people, buildings, and
infrastructure to hazards and focuses on (1) hazard identification; (2) impacts of hazards on physical,
social, and economic assets; (3) vulnerability identification; and (4) estimates of the cost of damage or
costs that could be avoided through mitigation.
Severe Repetitive Loss Property: Any NFIP-insured property that, since 1978 and regardless of any changes
of ownership during that period, that has had four or more separate claim payments made under a
standard flood insurance policy, with the amount of each claim exceeding $5,000 and with the cumulative
amount of such claims payments exceeding $20,000; or at least two separate claims payments made
under a standard flood insurance policy with the cumulative amount of such claim payments exceed the
fair market value of the insured building on the day before each loss.
Special Flood Hazard Area: The base floodplain delineated on a Flood Insurance Rate Map. The SFHA is
mapped as a Zone A in river situations and zone V in coastal situations. The SFHA may or may not
encompass all of a community’s flood problems.
Stakeholder: Business leaders, civic groups, academia, non-profit organizations, major employers,
managers of critical facilities, farmers, developers, special purpose districts, and others whose actions
could impact floodplain management.
Vulnerability: An asset’s susceptibility to damage during a hazard event. Vulnerability depends on an
asset’s construction, contents, and the economic value of its functions.
Watershed: An area that drains down-gradient from areas of higher land to areas of lower land to the lowest
point, a common drainage basin.
Zoning Ordinance: An ordinance that designates allowable land use and intensities for a local jurisdiction.
Zoning ordinances consist of two components: a zoning text and a zoning map.
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
A-1
Appendix A. Public Outreach Materials
APPENDIX A. PUBLIC OUTREACH MATERIALS
Extreme Heat Warning in Effect Until August 8
Select trails will be restricted from 8 a.m. to 5 p.m. at Camelback Mountain Preserve,
Phoenix Mountains Preserve and South Mountain Park and Reserve. Learn More. Read
tips on how to stay safe and find Heat Relief locations at Phoenix.gov/Summer.
City of Phoenix official website
Search
Menu
Administration
City Departments
City Engineer
Floodplain Management
Floodplain Management Plan
Floodplain Management Plan
The City of Phoenix participates in the
National Flood Insurance Program's (NFIP)
Community Rating System (CRS). As part of
the program, the City is updating its existing
Floodplain Management Plan (FMP).
The plan identifies flood hazards in the community, sets goals, and recommends a
program of activities to address the City's vulnerability to flooding. It also addresses
public education about loss reduction measures and the beneficial functions of
floodplains to reduce flood hazards within the City.
In accordance ARS §48-3616 and as required by the NFIP Community Rating System,
the City prepared a Floodplain Management Plan (FMP). The 2016 FMP can be viewed
on the City's website under the Floodplain Management subsection on the Street
Transportation Department Page. ARS §48-3616 requires that updates be prepared at
Department Menu
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least every five years and shall (1) indicate past efforts of the City in eliminating or
minimizing flood control problems, (2) state the planned future work of the City to
eliminate or minimize flood control problems, and (3) review and recommend a
program of activities to address the City's vulnerability to flooding and educate
residents about loss reduction measures and the beneficial functions of floodplains.
Helpful Resources
2025 Floodplain Management Plan Fact Sheet
2016 Floodplain Management Plan (Most Recent)
Metro Phoenix Drainage Master Plan
Floodplain Determination Form
Maricopa County Hazard Mitigation Plan
Glossary of Terms
If you are interested in more information on the City's FMP Update, please send an
email to Ryan.Bentz@phoenix.gov .
FMP Update Community Engagement
On May 22, 2025, the team hosted a Citywide Virtual Public Meeting at 6:00 p.m. to
learn about the plan and its goals. View or listen to the video below.
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As part of the 2025 update, a Floodplain Management Plan Committee (Committee)
has been established. The Committee is made up of representatives of the City of
Phoenix, State of Arizona, federal agencies, municipalities, organizations, and the
2025 Floodplain Managment Plan Public Meeting
2025 Floodplain Managment Plan Public Meeting
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general public. The Committee will help identify hazards, assess the problems, and
identify potential solutions.
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FMP Social Media Posts – Examples from Instagram
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April 2025
What is a Floodplain Management Plan?
The Floodplain Management Plan is an overall strategy of
programs, projects and measures aimed at reducing the
adverse impacts of flood hazards on the community. This plan
identifies flood risks, their impact on the community, and a
prioritized action plan for reducing flood risks. The National
Flood Insurance Program (NFIP) requires the city to review this
plan annually.
What are the benefits of this plan?
• Prioritizes flood management activities.
• Identifies improvement projects to reduce flooding risks.
• Educates the public and increases local awareness of
flooding risks.
• Creates successful partnerships with local, county and
government agencies.
• Strengthens the opportunity for resident cost savings on
flood insurance premiums.
o Residents currently benefit from a 25% reduction in
flood insurance premiums for policies located both in
and out of a FEMA Special Flood Hazard Area.
A lower CRS Class from the NFIP indicates better planning,
preparedness and mitigation, which results in a discounted
rate for property owners who purchase flood insurance.
City of Phoenix Floodplain Management Plan
FACT SHEET
PLAN PURPOSE & NEED
• Meets the Federal Emergency Management
Agency (FEMA) NFIP guidelines under the Flood
Insurance Administration
• Reflects the City’s floodplain management
efforts which contribute to the class rating.
• Strengthens the support and opportunity
for resident cost savings on flood
insurance premiums.
How can you contribute?
We seek your input for the City’s Floodplain
Management Plan. Your input is key to providing a
well-rounded plan to mitigate against flooding and
protect people, property, and the natural environment.
Please complete the public survey by visiting
www.surveymonkey.com/r/QDP2WZ3 or scan the QR
code below.
Join the virtual public meeting on May 22, 2025 at 6 PM
www.phoenix.gov/streets/meetings or scan the QR code
below.
Visit the City’s Floodplain Management Plan webpage
www.phoenix.gov/streets/fmp.html or scan the QR code
below.
2025 Floodplain Management Plan Survey
1 / 12
83.33%
15
72.22%
13
50.00%
9
27.78%
5
61.11%
11
61.11%
11
Q1
What floodplain issues are important to you? Check all that apply.
Answered: 18
Skipped: 0
Total Respondents: 18
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Knowing where
flood risk
exists.
Reducing flood
risks.
Preserving and
enhancing
riparian...
Opportunities
for recreation.
Protecting
water supply
and groundwa...
How climate
change affects
flood risk.
ANSWER CHOICES
RESPONSES
Knowing where flood risk exists.
Reducing flood risks.
Preserving and enhancing riparian habitat.
Opportunities for recreation.
Protecting water supply and groundwater recharge.
How climate change affects flood risk.
2025 Floodplain Management Plan Survey
2 / 12
18.75%
3
18.75%
3
62.50%
10
12.50%
2
37.50%
6
Q2
How do you receive information about flooding? Check all that apply.
Answered: 16
Skipped: 2
Total Respondents: 16
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Cell phone
alerts
(Maricopa...
Radio station
TV/News Station
Social media
Website or
online sources
ANSWER CHOICES
RESPONSES
Cell phone alerts (Maricopa County RAVE)
Radio station
TV/News Station
Social media
Website or online sources
2025 Floodplain Management Plan Survey
3 / 12
Q3
What flooding situations have you experienced? Check all that apply.
Answered: 14
Skipped: 4
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
I have
experienced
flooding whi...
I have altered
my route due to
street...
I have driven
through flooded
washes to ge...
My home has
flooded.
One or more
buildings on my
property hav...
My property
has flooded
(but no...
A wash on my
property has
flowed.
My property
has experienced
erosion due ...
I have been
stranded trying
to leave or...
Emergency
services in my
area have be...
2025 Floodplain Management Plan Survey
4 / 12
78.57%
11
78.57%
11
35.71%
5
7.14%
1
14.29%
2
14.29%
2
7.14%
1
7.14%
1
7.14%
1
7.14%
1
Total Respondents: 14
ANSWER CHOICES
RESPONSES
I have experienced flooding while driving.
I have altered my route due to street flooding.
I have driven through flooded washes to get to my destination.
My home has flooded.
One or more buildings on my property have flooded.
My property has flooded (but no buildings).
A wash on my property has flowed.
My property has experienced erosion due to flooding.
I have been stranded trying to leave or return home due to flooding.
Emergency services in my area have been delayed due to flooding.
2025 Floodplain Management Plan Survey
5 / 12
Q4
Please describe any other flooding hazards or drainage problems that
occur in your area. Provide cross streets closest to the area of concern.
Answered: 11
Skipped: 7
2025 Floodplain Management Plan Survey
6 / 12
11.76%
2
11.76%
2
5.88%
1
35.29%
6
11.76%
2
5.88%
1
17.65%
3
Q5
Do you have flood insurance?
Answered: 17
Skipped: 1
TOTAL
17
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Yes, my
mortgage
requires...
Yes, I like to
be safe.
Yes, I have
contents
coverage.
No, I don’t
have a mortgage
that require...
No, it never
floods here.
No, I rent and
didn’t know
that content...
I don't know.
ANSWER CHOICES
RESPONSES
Yes, my mortgage requires building coverage.
Yes, I like to be safe.
Yes, I have contents coverage.
No, I don’t have a mortgage that requires it.
No, it never floods here.
No, I rent and didn’t know that contents coverage was available.
I don't know.
2025 Floodplain Management Plan Survey
7 / 12
47.06%
8
5.88%
1
17.65%
3
11.76%
2
0.00%
0
17.65%
3
Q6
Have you taken steps to reduce the impacts of flooding on your
property and/or prepared for flooding?
Answered: 17
Skipped: 1
TOTAL
17
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Yes, I have
taken steps to
reduce damag...
Yes, I know
what to do
during a flood.
No, it doesn’t
concern me.
No, I rent.
No, I don't
have the money.
No, I didn’t
know what to
do.
ANSWER CHOICES
RESPONSES
Yes, I have taken steps to reduce damages to my property.
Yes, I know what to do during a flood.
No, it doesn’t concern me.
No, I rent.
No, I don't have the money.
No, I didn’t know what to do.
2025 Floodplain Management Plan Survey
8 / 12
18.75%
3
18.75%
3
6.25%
1
6.25%
1
18.75%
3
56.25%
9
Q7
What steps have been taken in your area or neighborhood to reduce
flood risk? Check all that apply.
Answered: 16
Skipped: 2
Total Respondents: 16
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Constructed
Improvements
(channels,...
Education (HOA
meetings,
handouts,...
Habitat and
Open Space
Preservation
Installation
of Water
Harvesting o...
Preventative
Maintenance
(brush and...
I don’t know
ANSWER CHOICES
RESPONSES
Constructed Improvements (channels, culverts, crossings, and erosion control)
Education (HOA meetings, handouts, public events)
Habitat and Open Space Preservation
Installation of Water Harvesting or Other Green Infrastructure
Preventative Maintenance (brush and debris removal)
I don’t know
2025 Floodplain Management Plan Survey
9 / 12
0.00%
0
8.33%
1
41.67%
5
8.33%
1
8.33%
1
16.67%
2
33.33%
4
0.00%
0
66.67%
8
Q8
Which of the following activities in which you have participated? Check
all that apply.
Answered: 12
Skipped: 6
Total Respondents: 12
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Resolving
Complaints
Getting
Technical
Assistance
Education &
Outreach
(Including...
Using Flood
Warning Systems
Implementing
Habitat
Management,...
Implementing
Infrastructure
Improvements
Visiting
Multi-Use
Recreation...
Obtaining
Permit
Using the
Floodplain
Viewer to ch...
ANSWER CHOICES
RESPONSES
Resolving Complaints
Getting Technical Assistance
Education & Outreach (Including attending project meetings and workshops.) Using Flood Maps & Studies, or Obtaining
Elevation Certificates
Using Flood Warning Systems
Implementing Habitat Management, Water Harvesting and Green Infrastructure
Implementing Infrastructure Improvements
Visiting Multi-Use Recreation Sites
Obtaining Permit
Using the Floodplain Viewer to check if your home is in a FEMA designated floodplain?
2025 Floodplain Management Plan Survey
10 / 12
Q9
Is there anything else you would like us to know to help shape the
Floodplain Management Plan?
Answered: 5
Skipped: 13
2025 Floodplain Management Plan Survey
11 / 12
23.53%
4
5.88%
1
17.65%
3
52.94%
9
Q10
Would you be interested in participating further in the Floodplain
Management Plan process?
Answered: 17
Skipped: 1
TOTAL
17
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Yes, to
receive meeting
announcement...
Yes, to
complete a more
detailed sur...
Yes, to review
the Draft FMP.
No, thank you.
ANSWER CHOICES
RESPONSES
Yes, to receive meeting announcements and project update emails.
Yes, to complete a more detailed survey about flood hazard awareness and management preferences.
Yes, to review the Draft FMP.
No, thank you.
2025 Floodplain Management Plan Survey
12 / 12
0.00%
0
0.00%
0
0.00%
0
0.00%
0
0.00%
0
0.00%
0
0.00%
0
0.00%
0
100.00%
16
0.00%
0
Q11
Please provide your email address.
Answered: 16
Skipped: 2
ANSWER CHOICES
RESPONSES
Name
Company
Address
Address 2
City/Town
State/Province
ZIP/Postal Code
Country
Email Address
Phone Number
City of Phoenix Neighborhood Association
Meeting Presentation
8/6/2025
Presented: April 23, 2025
1
2025 FLOODPLAIN MANAGEMENT PLAN
Public meeting:
April 23, 2025
PROJECT TEAM
Nazar Nabaty – Floodplain Administrator/Floodplain Group Manager
Ryan Bentz – Project Manager
Nick Ramirez – Principal Engineering Tech
Matt Hann – Consultant (Black & Veatch)
Zaria Sanchez – Consultant (Black & Veatch)
2
1
2
City of Phoenix Neighborhood Association
Meeting Presentation
8/6/2025
Presented: April 23, 2025
2
MEETING AGENDA
• National Flood Insurance Program
• Community Rating System
• What is the Floodplain Management Plan?
• Floodplain Management Plan Development
• Timeline
• How can you get involved?
• Q&A
3
NATIONAL FLOOD
INSURANCE PROGRAM (NFIP)
•
National Flood Insurance Act of 1968
– Reducing future flood damage
– Protecting property owners
•
Mapping
•
Flood Insurance
•
Regulations
•
Community Rating System (CRS)
4
3
4
City of Phoenix Neighborhood Association
Meeting Presentation
8/6/2025
Presented: April 23, 2025
3
COMMUNITY RATING SYSTEM
(CRS)
• Voluntary Incentive Program
• Above and beyond the NFIP minimum requirements
• Incentives for flood insurance premiums
• Phoenix - Class 5 Community (25% Flood Insurance Premium Reduction)
5
6
5
6
City of Phoenix Neighborhood Association
Meeting Presentation
8/6/2025
Presented: April 23, 2025
4
FLOODPLAIN MANAGEMENT PLAN (FMP)
OVERVIEW
•
Part of the Community Rating System
•
Identifies flood hazards
•
Sets goals
•
Provides recommendations to address the
City’s vulnerability to flooding
•
Updates existing Floodplain Management
Plan
– As required by Community Rating System
7
FLOODPLAIN MANAGEMENT PLAN
(FMP) COMMITTEE
• Development of the 2025 Phoenix Floodplain Management Plan was
supported by the following:
• Arizona Department of Emergency and Military Affairs
• Arizona Department of Transportation
• Arizona Department of Water Resources
• Arizona State Land Department
• Flood Control District of Maricopa County
• Maricopa County Department of Emergency Management
• National Weather Service / National Oceanic and Atmospheric Administration
• City of Phoenix Residents
8
7
8
City of Phoenix Neighborhood Association
Meeting Presentation
8/6/2025
Presented: April 23, 2025
5
FLOODPLAIN MANAGEMENT
PLAN (FMP) DEVELOPMENT STEPS
• Step 1 – Organize
• Step 2 – Involve the Public
• Step 3 – Coordinate
• Step 4 – Assess the Hazard (FMP Committee Meeting #1)
• Step 5 – Assess the Problem (FMP Committee Meeting #2)
• Step 6 – Set Goals (FMP Committee Meeting #3)
• Step 7 – Review Possible Actions (FMP Committee Meeting #4)
• Step 8 – Draft an Action Plan (FMP Committee Meeting #5)
• Step 9 – Adopt a Plan
• Step 10 – Implement, Evaluate, and Revise
9
2025 FLOODPLAIN MANAGEMENT
PLAN (FMP) HAZARDS IDENTIFIED
• Special Flood Hazard Areas (Floodplains)
• Alluvial Fans
• Transitions from Mountain to Urban
• Dams and Levees
• Other Non-Flood Related Hazards
• Wildfires
• Drought
• Funding
10
9
10
City of Phoenix Neighborhood Association
Meeting Presentation
8/6/2025
Presented: April 23, 2025
6
2025 FLOODPLAIN MANAGEMENT
PLAN (FMP) GOALS
• Educate public, policy makers, and City leaders on stormwater and
floodplain management and risks
• Coordinate with other jurisdictions and agencies to mitigate flooding hazards
and improve emergency response
• Reduce the danger of flood hazards to people, property, critical
infrastructure/facilities, and natural resources
• Establish proactive maintenance and preventative measures for stormwater
infrastructure
• Utilize public funding in the most effective manner for stormwater and
floodplain management
11
2025 FLOODPLAIN MANAGEMENT
PLAN (FMP) ACTION ITEMS
• Currently Under Development and Finalization
• Will address FMP Goals previously provided and will also focus on the following:
• Preventive
• Property Protection
• Natural Resource Protection
• Emergency Services
• Structural Projects (e.g., Storm drains, channels)
• Public Information
12
11
12
City of Phoenix Neighborhood Association
Meeting Presentation
8/6/2025
Presented: April 23, 2025
7
FLOODPLAIN MANAGEMENT PLAN
(FMP) TIMELINE
13
April-May 2025
• Draft FMP
Development
June 2025
• FMP Public
Review Period
July 2025
• Finalize FMP
Aug/Sept 2025
• City Council
Adoption of
2025 FMP
HOW CAN YOU GET INVOLVED
AND PROVIDE FEEDBACK…?
14
• FMP Public Survey (https://www.surveymonkey.com/r/QDP2WZ3)
• City of Phoenix Floodplain Management Plan Webpage
(https://phoenix.gov/streets/fmp)
FMP Public
Survey
City’s FMP
Webpage
13
14
City of Phoenix Neighborhood Association
Meeting Presentation
8/6/2025
Presented: April 23, 2025
8
QUESTIONS…?
15
FMP Public
Survey
City’s FMP
Webpage
15
April 23, 2025 - South Mountain and Laveen Chamber of Commerce Attendance List
FMP Neighborhood Association Presentation
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
B-1
Appendix B. Stakeholder Outreach Materials
APPENDIX B. STAKEHOLDER OUTREACH MATERIALS
Flood Control District of Maricopa County Outreach Meeting – 3/19/2025 at 2:00pm
Kathryn Gross - FCDMC
Matt Hann – Black & Veatch (on behalf of the City of Phoenix)
Do you have any recent, ongoing, or future projects related to stormwater, flooding, or
floodplains adjacent to or with the City of Phoenix?
o
Numerous projects have been completed.
o
Ongoing – Metro Phoenix ADMS/P Update
o
Support for Hohokam Flood Mitigation Project
o
Dam safety for the dams surrounding City of Phoenix – annual exercises for response
o
Small Project Assistance Program
Is there any data or information that can be shared related to the project(s)?
o
Working in direct partnership with City of Phoenix.
What are/will be the completion date(s) of the project(s)?
o
Metro Phoenix ADMS/P should be completed within the next two years
Would you like to be notified of when the Draft Floodplain Management Plan for the City of
Phoenix is ready for stakeholder and public review?
o
Yes.
Step 3: Coordinate - Stakeholder Outreach
NOAA/NWS Outreach Meeting – 3/28/2025 at 11:30am
Mike Schaffner – NOAA/NWS
Matt Hann – Black & Veatch (on behalf of the City of Phoenix)
Do you have any recent, ongoing, or future projects related to stormwater, flooding, or
floodplains adjacent to or with the City of Phoenix?
o
Constantly working to improve thresholds for warnings and situational awareness for
municipalities and agencies.
Is there any data or information that can be shared related to the project(s)?
o
All information is provided publicly.
What are/will be the completion date(s) of the project(s)?
o
Ongoing and improving.
Would you like to be notified of when the Draft Floodplain Management Plan for the City of
Phoenix is ready for stakeholder and public review?
o
Yes. Tom Frieders will be stepping in to support.
Step 3: Coordinate - Stakeholder Outreach
Arizona Department of Transportation Outreach Meeting – 4/3/2025 at 9:00am
Robert Guerrero - ADOT
Matt Hann; Zaria Sanchez – Black & Veatch (on behalf of the City of Phoenix)
Do you have any recent, ongoing, or future projects related to stormwater, flooding, or
floodplains adjacent to or with the City of Phoenix?
o
I-17 Storm Drain project Greenway to ACDC Canal.
o
Broadway Curve.
o
Loop 101 Widening.
o
Scatter Wash maintenance – annual frequency taken care of prior to monsoon season.
o
New River and Deadman Wash Levee inspections completed annually. Completing a
more detailed 5-year inspection currently.
o
Future private development around Loop 101 near Desert Ridge that will require
coordination with ADOT.
o
Working with Phoenix Water Services Department for storm drain outlet for 23rd Avenue
treatment plant as it shares an outfall with ADOT.
Is there any data or information that can be shared related to the project(s)?
o
Work directly with the City for coordination over the next 5-years.
What are/will be the completion date(s) of the project(s)?
o
I-17 Storm Drain project Greenway to ACDC Canal has been completed.
o
Broadway Curve to be complete in 2025.
o
Loop 101 Widening 75th Avenue estimated to be completed in early 2027.
Would you like to be notified of when the Draft Floodplain Management Plan for the City of
Phoenix is ready for stakeholder and public review?
o
Yes. Want to be aware of how this may impact ADOT.
Step 3: Coordinate - Stakeholder Outreach
Central Arizona Conservation Alliance Outreach Meeting – 4/2/2025 at 2:30pm
Challie Facemire - CAZCA
Matt Hann; Zaria Sanchez – Black & Veatch (on behalf of the City of Phoenix)
Do you have any recent, ongoing, or future projects related to stormwater, flooding, or
floodplains adjacent to or with the City of Phoenix?
o
No recent, ongoing, or future projects within the City of Phoenix. Have a web map
natural resource infrastructure viewer to support educating the public.
o
https://web.tplgis.org/cazca_plan/
Is there any data or information that can be shared related to the project(s)?
o
N/A
What are/will be the completion date(s) of the project(s)?
o
N/A
Would you like to be notified of when the Draft Floodplain Management Plan for the City of
Phoenix is ready for stakeholder and public review?
o
Yes.
Step 3: Coordinate - Stakeholder Outreach
Arizona Department of Water Resources Outreach Meeting – 4/8/2025 at 2:30pm
Brian Cosson - ADWR
Matt Hann; Zaria Sanchez – Black & Veatch (on behalf of the City of Phoenix)
Do you have any recent, ongoing, or future projects related to stormwater, flooding, or
floodplains adjacent to or with the City of Phoenix?
o
None.
Is there any data or information that can be shared related to the project(s)?
o
N/A
What are/will be the completion date(s) of the project(s)?
o
N/A
Would you like to be notified of when the Draft Floodplain Management Plan for the City of
Phoenix is ready for stakeholder and public review?
o
Yes.
Step 3: Coordinate - Stakeholder Outreach
City of Scottsdale Outreach Meeting – 4/3/2025 at 3:00pm
Hasan Mushtaq – City of Scottsdale
Matt Hann; Zaria Sanchez – Black & Veatch (on behalf of the City of Phoenix)
Do you have any recent, ongoing, or future projects related to stormwater, flooding, or
floodplains adjacent to or with the City of Phoenix?
o
Recently completed – Rawhide Wash Flood Hazard Mitigation Project – channelization,
new levees and embankments, and floodplain delineation updates are pending.
Is there any data or information that can be shared related to the project(s)?
o
Rawhide Wash was a tri-party project with Phoenix, Scottsdale, and Flood Control
District of Maricopa County
What are/will be the completion date(s) of the project(s)?
o
Completed – February 2025
Would you like to be notified of when the Draft Floodplain Management Plan for the City of
Phoenix is ready for stakeholder and public review?
o
Yes.
Step 3: Coordinate - Stakeholder Outreach
Town of Paradise Valley Outreach Meeting – 4/10/2025 at 3:00pm
Shar Johnson – Town of Paradise Valley
Matt Hann; Zaria Sanchez – Black & Veatch (on behalf of the City of Phoenix)
Do you have any recent, ongoing, or future projects related to stormwater, flooding, or
floodplains adjacent to or with the City of Phoenix?
o
Town is currently development a Stormwater Master Plan.
Is there any data or information that can be shared related to the project(s)?
o
Yes, potentially there is information to share.
What are/will be the completion date(s) of the project(s)?
o
Stormwater Master Plan anticipated completion is June 30, 2025.
Would you like to be notified of when the Draft Floodplain Management Plan for the City of
Phoenix is ready for stakeholder and public review?
o
Yes.
Step 3: Coordinate - Stakeholder Outreach
Arizona State Land Department Outreach Meeting – 4/11/2025 at 10:00am
Mark Edelman; Manny Patel - ASLD
Matt Hann – Black & Veatch (on behalf of the City of Phoenix)
Do you have any recent, ongoing, or future projects related to stormwater, flooding, or
floodplains adjacent to or with the City of Phoenix?
o
Paradise Ridge – flood control project.
Is there any data or information that can be shared related to the project(s)?
o
Working in direct partnership with City of Phoenix.
What are/will be the completion date(s) of the project(s)?
o
Tentatively completing Paradise Ridge by end of 2027.
Would you like to be notified of when the Draft Floodplain Management Plan for the City of
Phoenix is ready for stakeholder and public review?
o
Yes.
Step 3: Coordinate - Stakeholder Outreach
Arizona Forward Outreach Meeting – 4/14/2025 at 4:00pm
Lori Singleton – Arizona Forward
Matt Hann; Zaria Sanchez – Black & Veatch (on behalf of the City of Phoenix)
Do you have any recent, ongoing, or future projects related to stormwater, flooding, or
floodplains adjacent to or with the City of Phoenix?
o
No.
Is there any data or information that can be shared related to the project(s)?
o
N/A
What are/will be the completion date(s) of the project(s)?
o
N/A
Would you like to be notified of when the Draft Floodplain Management Plan for the City of
Phoenix is ready for stakeholder and public review?
o
Yes.
Step 3: Coordinate - Stakeholder Outreach
AZ STORM Outreach Meeting – 4/15/2025 at 1:30pm
Josh Blakey – AZ STORM
Matt Hann – Black & Veatch (on behalf of the City of Phoenix)
Do you have any recent, ongoing, or future projects related to stormwater, flooding, or
floodplains adjacent to or with the City of Phoenix?
o
Ongoing public outreach projects for stormwater pollution and quality at different
events around the Valley.
Is there any data or information that can be shared related to the project(s)?
o
N/A
What are/will be the completion date(s) of the project(s)?
o
N/A
Would you like to be notified of when the Draft Floodplain Management Plan for the City of
Phoenix is ready for stakeholder and public review?
o
Yes
Step 3: Coordinate - Stakeholder Outreach
Maricopa Department of Transportation Outreach Meeting – 4/16/2025 at 1:00pm
Bassem Naba - MCDOT
Matt Hann; Zaria Sanchez – Black & Veatch (on behalf of the City of Phoenix)
Do you have any recent, ongoing, or future projects related to stormwater, flooding, or
floodplains adjacent to or with the City of Phoenix?
o
No projects that are floodplain related.
Is there any data or information that can be shared related to the project(s)?
o
N/A
What are/will be the completion date(s) of the project(s)?
o
N/A
Would you like to be notified of when the Draft Floodplain Management Plan for the City of
Phoenix is ready for stakeholder and public review?
o
Yes.
Step 3: Coordinate - Stakeholder Outreach
Maricopa County Department of Emergency Management Outreach Meeting – 4/29/2025 at 9:30am
Chris Snell – Emergency Management Coordinator
Matt Hann; Zaria Sanchez – Black & Veatch (on behalf of the City of Phoenix)
Do you have any recent, ongoing, or future projects related to stormwater, flooding, or
floodplains adjacent to or with the City of Phoenix?
o
No, MCDEM does not, but there is an SRP project at Bartlett Dam
Is there any data or information that can be shared related to the project(s)?
o
Just the publicly available information
What are/will be the completion date(s) of the project(s)?
o
Expected Completion – Mid 2030’s
Would you like to be notified of when the Draft Floodplain Management Plan for the City of
Phoenix is ready for stakeholder and public review?
o
Yes
Step 3: Coordinate - Stakeholder Outreach
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
C-1
Appendix C. Meeting Documentation
APPENDIX C. MEETING DOCUMENTATION
City of Phoenix
Office of the City Engineer
Floodplain Management
200 West Washington Street, 5th Floor
Phoenix, Arizona, 85003
The City of Phoenix (City) administers the National Flood Insurance Program’s (NFIP)
Community Rating System for the City. As part of the program, the City is updating its Floodplain
Management Plan (FMP). The plan identifies flood hazards in the community, sets goals, and
recommends a program of activities to address the county’s vulnerability to flooding. It also
addresses public education about loss reduction measures and the beneficial functions of
floodplains to reduce flood hazards within the county.
You have been identified as an important participant in FMP Committee for the 2025 update. As
a committee member, you will need to attend all meetings to provide a meaningful contribution by
being aware of previous group discussions.
The meetings will be held in Assembly Room A at the Phoenix City Hall, 200 W Washington
St, Phoenix, AZ 85003. Please plan to arrive early to allow time to pass through security and
obtain a visitors’ badge. There is paid public parking available at the public parking garage at the 305
Garage located at 29 South 4th Avenue – bring your parking ticket into City Hall for reduced price
validation:
Date/Time
Purpose
Wednesday
Jan. 15 9 a.m. – 11:00
Assess the hazard
Wednesday
Feb. 5
9 a.m. – 11:00
Assess the problem
Wednesday
Feb. 26
9 a.m. – 11:00
Set goals
Wednesday Mar. 19
9 a.m. – 11:00
Review possible activities
Wednesday
Apr. 09
9 a.m. – 11:00
Draft an action plan
Please kindly note that if you are marked as “optional” on this invite, you are assigned as the
backup attendee for your department/organization and your attendance is not required, unless
the primary attendee is unable to attend.
If you would like additional information on the plan update, you may reach me at 602-448-6360
or ryan.bentz@phoenix.gov.
City of Phoenix
Office of the City Engineer
Floodplain Management
200 West Washington Street, 5th Floor
Phoenix, Arizona, 85003
PARKING AND LOCATION MAP
8
7
6
4
5
6
7
¯
0
8,000
4,000
Feet
FLOODPLAIN MANAGEMENT PLAN
2025
CITY OF PHOENIX PROJECT NUMBER
ST83140150
JANUARY 2025
Legend
FEMA SPECIAL FLOOD
HAZARD AREA
CITY OF PHOENIX
FLOODPLAIN MANAGEMENT
PLAN 2025
CITY COUNCIL
DISTRICTS
SOUTH 6, 7 AND 8
8
7
3
6
5
4
1
2
7
6
¯
0
10,000
5,000
Feet
FLOODPLAIN MANAGEMENT PLAN
2025
CITY OF PHOENIX PROJECT NUMBER
ST83140150
JANUARY 2025
Legend
FEMA SPECIAL FLOOD
HAZARD AREA
CITY OF PHOENIX
FLOODPLAIN MANAGEMENT
PLAN 2025
CITY COUNCIL
DISTRICTS
4, 5, and 6 NORTH
2
1
3
6
5
¯
0
11,000
5,500
Feet
FLOODPLAIN MANAGEMENT PLAN
2025
CITY OF PHOENIX PROJECT NUMBER: ST83140150
JANUARY 2025
Legend
FEMA SPECIAL
FLOOD HAZARD
AREA
CITY OF PHOENIX
FLOODPLAIN MANAGEMENT
PLAN 2025
CITY COUNCIL
DISTRICTS
1, 2, AND 3
City of Phoenix Floodplain Management Plan (FMP) 2025
FMP Committee Meeting #1
January 15, 2025
AGENDA
▪Safety Moment
▪Introductions
▪City Engineer Welcome
▪Overview of National Flood Insurance Program (NFIP)
▪Overview of CRS Activity 510 – Floodplain Management Plan
▪Overview of current FMP – 2016
▪Where We Want to Be – FMP 2025
▪Next Steps
2
A BELIEF THAT IT IS SAFE TO TAKE
INTERPERSONAL RISKS: THAT ONE WILL NOT
BE PUNISHED OR HUMILIATED FOR SPEAKING
UP WITH IDEAS, QUESTIONS, CONCERNS, OR
MISTAKES.
SAFETY MOMENT –
PSYCHOLOGICAL SAFETY
3
•
ANYONE CAN ASK QUESTIONS WITHOUT
LOOKING STUPID.
•
ANYONE CAN ASK FOR FEEDBACK
WITHOUT LOOKING INCOMPETENT.
•
ANYONE CAN BE RESPECTFULLY CRITICAL
WITHOUT APPEARING NEGATIVE.
•
ANYONE CAN SUGGEST INNOVATIVE IDEAS
WITHOUT BEING PERCEIVED AS
DISRUPTIVE.
INTRODUCTIONS
4
•
NAME
•
ORGANIZATION
•
ROLE WITH FLOOD PLANNING,
MITIGATION, AND/OR
EMERGENCY MANAGEMENT
5
CITY ENGINEER
WELCOME STATEMENT
NATIONAL FLOOD
INSURANCE PROGRAM
• Mapping
• Flood Insurance
• Regulations
• Community Rating System
(CRS)
6
COMMUNITY RATING
SYSTEM (CRS)
• Voluntary Incentive Program
• Above and beyond the NFIP
minimum requirements
• Incentives for flood insurance
premiums
• Phoenix - Class 5 Community
• Phoenix - Goal for Class 4
7
CRS Classes and Discount Table
CRS Class
10
9
8
7
6
5
4
3
2
1
CRS Discount
(Premium Reduction)
0%
5%
10%
15%
20%
25%
30%
35%
40%
45%
RISING COSTS OF NATURAL DISASTERS
Arizona Average Home Insurance Premium Changes in Last 4 Years
2020 Annual
Average Home
Insurance Premium
2024 Annual
Average Home
Insurance Premium
Change in Average Home
Insurance Premiums from
2020 to 2024
$1,255
$1,554
+$299 (+24%)
8
Source: US Joint Economic Committee
December 2024
CRS PROGRAM PARTICIPATION
•
1,500+ Communities in CRS
•
22,000+ Communities in NFIP
•
~8% of NFIP participates in CRS
•
More than 70% of all flood insurance
policies are written in CRS
Communities
Data as of October 2020
Source: CRSResources.org
9
• NFIP Supported Program
• Goals
• Reduce & Avoid Flood Damage to Insurable
Properties
• Strengthen & Support the Insurance Aspects of the
NFIP
• Foster Comprehensive Floodplain Management
• 4 Series → 19 Activities → 90+ Elements
• Public Information Activities (300 Series)
• Mapping & Regulations (400 Series)
• Flood Damage Reduction Activities (500 Series)
• Warning & Response (600 Series)
CRS BACKGROUND
10
300 Series:
Public
Information
Activities
310 – Elevation
Certificates
320 – Map Information
Service
330 – Outreach
Projects
340 – Hazard Disclosure
350 - Flood Protection
Information
360 – Flood Protection
Assistance
370 – Flood Insurance
Promotion
400 Series:
Mapping
and
Regulations
410 – Floodplain
Mapping
420 – Open Space
Preservation
430 – Higher Regulatory
Standards
440 – Flood Data
Maintenance
450 – Stormwater
Management
500 Series:
Flood
Damage
Reduction
510 – Floodplain
Management Planning
520 – Acquisition and
Relocation
530 – Flood Protection
540 – Drainage System
Maintenance
600 Series:
Warning
and
Response
610 – Flood Warning
and Response
620 – Levees
630 – Dams
11
Overview of CRS Activity 510 –
Floodplain Management plan
• CRS Class 4 Prerequisites
• FMP Committee Participant Roles
• Review of FMP Committee Timeline
•
5 Committee Meetings
•
At least one representative from each
participating organization must be present
at each of the 5 Committee Meetings
12
OVERVIEW OF CRS ACTIVITY 510 – FLOODPLAIN MANAGEMENT PLAN
13
•
Step 1 – Organize
•
Step 2 – Involve the Public
•
Step 3 – Coordinate
•
Step 4 – Assess the Hazard (FMP Committee Meeting #1) TODAY’S MEETING
•
Step 5 – Assess the Problem (FMP Committee Meeting #2)
•
Step 6 – Set Goals (FMP Committee Meeting #3)
•
Step 7 – Review Possible Actions (FMP Committee Meeting #4)
•
Step 8 – Draft an Action Plan (FMP Committee Meeting #5)
•
Step 9 – Adopt a Plan
•
Step 10 – Implement, Evaluate, and Revise
Current Phoenix FMP (2016)
1.
Hazards Identified
2.
Status of 2016 Goals & Plans
3.
Lessons Learned
14
15
2016 HAZARDS IDENTIFIED
•Historic and Repetitive Flooding Areas
•Dam Failure
•Levee Failure
•Flooding
•Future Development Trends
•Earth Fissures
•Land Subsidence
•Other Hazards
• Drought
• Extreme Heat
• Severe Wind
• Wildfire
Goals and Action Items
1.
Reduce Risks that Threaten Life and Property
2.
Protect Critical Infrastructure
3.
Promote Hazard Mitigation
4.
Increase Public Awareness of Hazards
•Administrative Action Items – 3 Total
•Program Action Items – 9 Total
•Public Information Action Items – 6 Total
16
LESSONS LEARNED
1.
Need for FMP Committee
a)
Increased information on hazards and problems
b)
Community-centered goals and action items
2.
Additional Involvement with Public
a)
Webpage to allow for following FMP progress
b)
Public Survey to gather additional information
c)
Public Meetings
3.
Additional Involvement with Stakeholders
a)
Separate, short interviews to gather more
feedback outside FMP Committee meetings
4.
Annual Tracking and Updates with
Committee
17
ASSESS THE HAZARD
BREAK OUT – 30 MINUTES
18
Group 1
City Council Districts
1, 2, and 3
Group 2
City Council Districts
4, 5, and 6 North
Group 1
City Council Districts
6 South, 7, and 8
Describe local flood hazard.
a) How often it floods
b) Locations of areas that flood
c) Source or cause of flooding
19
ASSESS THE HAZARD
REPORT BACK
20
GROUP 1
CITY COUNCIL DISTRICTS
1, 2, AND 3
ASSESS THE HAZARD
REPORT BACK
21
GROUP 2
CITY COUNCIL DISTRICTS
4, 5, AND 6 NORTH
ASSESS THE HAZARD
REPORT BACK
22
GROUP 3
CITY COUNCIL DISTRICTS
6 SOUTH, 7, AND 8
ASSESS THE HAZARD
REPORT BACK
WHERE WE WANT TO BE
FOR 2025 FMP
•
Update and identify hazards in Phoenix
•
Understand the problems associated
with the hazards
•
Establish new goals and actionable
timelines
•
Evaluate potential actions and known
challenges for new goals
•
Prepare a five-year action plan with
progress tracking metrics
•
Adopt and Implement the plan
•
Frequent monitoring of progress toward
goals
23
NEXT STEPS:
24
•
Collect and incorporate hazard and mitigation data
•
Ongoing coordination with FMP Committee
•
Conduct Public and Stakeholder Involvement – Specific Audiences
•
Responsibilities of participants
•
Committee Members
•
City Representatives
•
Consultant Team
Questions?
Next FMP Committee Meeting | February 5, 2025 |9am City of Phoenix City Hall
City of Phoenix | FMP COMMITTEE MEETING #1 – FLOODPLAIN MANAGEMENT PLAN 2025
JANUARY 15, 2025
Phoenix Floodplain Management Plan 2025 (ST83140150)
Committee Meeting #1
January 15, 2025 at 9:00 AM – 11:00 AM
MEETING MINUTES
1. Safety moment – 3 min
2. Introductions – Around the room – 15 min
3. City Council Engineer Welcome Statement – 5 min
4. Overview of the National Flood Insurance Program (NFIP) – 10 min
a. What is the NFIP?
b. Community Rating System (CRS)
i. Need at least one rep from the organization.
ii. Question: What is the extra 5% discount? What does that amount to?
5. Overview of CRS Activity 510 – Floodplain Management Plan (FMP) – 5 min
a. Overview and purpose of FMP
i. Manny Patel: What specific activities are needed from the 300, 400, 500, etc. series to
get class 4?
Matt Hann: We will need points from all categories. The City has other activities going
on that contribute to the overall goal.
b. Review of FMP Committee Timeline and Expectations
i. Manny Patel: How were committee members selected?
Matt Hann: We chose organizations that are involved with floodplain management,
emergency management, or impacted by it.
ii. Manny Patel: How often is the FMP updated?
Matt Hann: About every 5 years.
Bryan Cosson: Other Class 4 communities may be required to do 3 to 5-year cycles.
6. FMP Committee Members Roles and Responsibilities – 2 min
a. Attendance at each FMP Committee Meeting – at least one person from each organization
7. Overview of Current Phoenix FMP (2016) – 15 min
a. Identified Hazards & Problems
b. Status of 2016 Goals and Action Plan
c. Lessons Learned
8. Breakout For New/Updated Hazards – 30 min
9. Reporting From Breakouts – 20 min
GROUP 1 Potential Hazards (City Council Districts 1, 2, & 3):
Individual property owners have local drainage or flooding concerns.
The transition from mountains to urban landscape creates flooding/drainage issues.
The city does have project in these areas to address flooding and drainage problems.
We discussed subdivisions placed on fill in floodplain fringe that now have ground level issues.
COMMITTEE MEETING #1 - MINUTES
Page 2
2231 East Camelback Road, Suite 300
Phoenix, Arizona 85016
602-381-4400
City of Phoenix | FMP COMMITTEE MEETING #1 – FLOODPLAIN MANAGEMENT PLAN 2025
JANUARY 15, 2025
Other factors include age of development, as earlier ones have higher risk of flooding than newer
ones based on changes in development standards.
Matt Hann: Majority of the City of Phoenix and Maricopa County dams and levees are in Group
1. We’ll have an inventory of levee and dams to document risks and elaborate on background in
the plan.
GROUP 2 Potential Hazards (City Council Districts 4, 5, & 6):
Andrew Hagglund: Older homes, from 50s and 60s, with flood irrigated lots.
A lot of local flooding, canals that back up water on berms, the natural washes.
The infrastructure is under capacity and not maintained. Portions of the Salt River back up
causing flooding along ADOT right of way. Flooding occurs in monsoon and winter.
GROUP 3 Potential Hazards (City Council Districts 6, 7, & 8):
Ryan Sauer: Floodplain delineation doesn’t reflect hazards, South Mountain floodplains not
mapped. We had a conversation on vegetation – private maintenance involves risk. Residents
want vegetation and we need to make sure it’s not impacting flows. We discussed Infill in south
Phoenix, large developments in Ahwatukee and how might those impact flows.
G1: There are different standards for wash maintenance. The primarily flow line and adjacent
part may be maintained differently, with different standards. One part may be clear cut and
other areas may be vegetated. We don’t have an even approach to wash maintenance.
Ryan Sauer: There needs to be a balance of what residents want, some want washes cleared,
others want vegetated washes.
Ryan Sauer: We discussed that in the future, there may be less rain and peak flows may be
different.
Matt Hann: Especially in unmapped hazard or older areas.
Question (G1): Pima is bringing in rules and standards for developments, does CRS give points for
these types of standards?
Matt Hann: It’s a component.
Ryan Sauer: 10-year, 100-year, different future storms are allocated different points.
Matt Hann: The County has started wanting to evaluate 500-year storms for Area Drainage
Master Studies, these are less likely but higher risk.
Question (G1): how often is 100-year storm updated?
Ryan Sauer: NOAA updates the national precipitation values typically 15-20 years – but, they
need to have enough new data to make the updates.
Kathryn Gross: Water studies are regional; storms may not be updated for smaller local storms.
Andrew Hagglund: The valley is microclimate, in a 1x1 mile intense storm it is hard to capture
and model it.
Ryan Sauer: In 2014 storm, sediment and boulders made their way onto Dobson by South
Mountain. Several City of Phoenix storm drain projects in the area.
COMMITTEE MEETING #1 - MINUTES
Page 3
2231 East Camelback Road, Suite 300
Phoenix, Arizona 85016
602-381-4400
City of Phoenix | FMP COMMITTEE MEETING #1 – FLOODPLAIN MANAGEMENT PLAN 2025
JANUARY 15, 2025
10. Next Steps – 5 min
a. Collect and incorporate hazard and mitigation data for Maricopa County
b. Ongoing coordination with FMP Committee
c. Conduct Public and Stakeholder Involvement – Specific Audiences
d. Public Survey & Website Updates
11. Adjourn
Next Meeting: Wednesday, February 5, 2025
Phoenix City Hall - 200 W Washington Street, 85003
Committee Meeting #2 – Assess the Problem
Wednesday, February 5, 2025
Committee Meeting #3 – Set Goals
Wednesday, February 26, 2025
Committee Meeting #4 – Review Possible Actions
Wednesday, March 19, 2025
Committee Meeting #5 – Draft an Action Plan
Wednesday, April 9, 2025
City of Phoenix Floodplain Management Plan (FMP) 2025
FMP Committee Meeting #2
February 05, 2025
AGENDA
Safety Moment
Introductions (If Needed)
Overview of FMP Mtg#1: Flood Hazard Identification
Impacts of Hazards – Assessing the Problem
Group Breakout – Hazards and Problems Discussion
Group Report Out and Discussion
Next Steps
2
SAFETY MOMENT –
OVERLOOKED WINTER HAZARDS
3
• DEHYDRATION
•
Drier, less humid air can exacerbate fluid loss
•
Hydrate early and often
• UV RAYS
•
Sun’s rays are harmful even during summer
•
Cover up, wear sunglasses and broad-
spectrum sunscreen
• CARBON MONOXIDE
•
Install/Test CO Detectors
This Photo by Unknown Author is licensed under CC BY-SA
INTRODUCTIONS
4
•
NAME
•
ORGANIZATION
•
ROLE WITH FLOOD PLANNING,
MITIGATION, AND/OR
EMERGENCY MANAGEMENT
OVERVIEW OF CRS ACTIVITY 510 – FLOODPLAIN MANAGEMENT PLAN
5
•
Step 1 – Organize
•
Step 2 – Involve the Public
•
Step 3 – Coordinate
•
Step 4 – Assess the Hazard (FMP Committee Meeting #1)
•
Step 5 – Assess the Problem (FMP Committee Meeting #2) TODAY’S MEETING
•
Step 6 – Set Goals (FMP Committee Meeting #3)
•
Step 7 – Review Possible Actions (FMP Committee Meeting #4)
•
Step 8 – Draft an Action Plan (FMP Committee Meeting #5)
•
Step 9 – Adopt a Plan
•
Step 10 – Implement, Evaluate, and Revise
6
2016 HAZARDS IDENTIFIED
•Historic and Repetitive Flooding Areas
•Dam Failure
•Levee Failure
•Flooding
•Future Development Trends
•Earth Fissures
•Land Subsidence
•Other Hazards
• Drought
• Extreme Heat
• Severe Wind
• Wildfire
2025 FMP Mtg #1:
FLOOD HAZARD IDENTIFICATION
•
Special Flood Hazard Areas
•
Riverine Flooding
•
Canal Embankments
•
Alluvial Fan
•
Transition from Mountain to Urban Landscape
•
Urban Flooding
•
Sheet Flow Channelized Flow
•
Developments on Fill in Floodplain Fringe
•
Local Flooding
•
Age of Development and Infrastructure
•
Under Capacity Infrastructure
•
Un-Delineated Flood Hazards
•
Wash and Basin Vegetation Maintenance
•
Infill Development
7
Additional Hazards for Consideration
•
Dam and Levee Failure
•
Other Non-Flood Related Hazards
•
Climate Change
•
Wildfires
•
Drought
•
Funding
8
Impacts of Hazards &
Assess the Problem
•
Life Safety
•
Emergency Warning and Response
•
Evacuations
•
Public Health
•
Health Hazards to Individuals – flood waters and mold
•
Critical Facilities and Infrastructure
•
Airports, Water Treatment, Fire and Police, Utilities
•
Schools, Hospitals, Senior Care Facilities
9
Impacts of Hazards &
Assess the Problem
•
Economy
•
Impacts to Major Employers
•
Natural Floodplain Functions
•
Areas Impacted
•
Environmental and Aesthetic Impacts
•
Development, Redevelopment, and Population
Trends
•
Future Impacts on community, watershed, and natural
resources
•
Future Flooding Conditions
10
ASSESS THE PROBLEM
BREAK OUT – 30 MINUTES
11
Group 3
City Council Districts
6 South, 7, and 8
Group 2
City Council Districts
4, 5, and 6 North
Group 1
City Council Districts
1, 2, and 3
Impacts Hazards on the following:
•
Life Safety
•
Public Health
•
Critical Facilities and Infrastructure
•
Economy
•
Natural Floodplain Functions
•
Development, Redevelopment,
and Population Trends
•
Future Flooding Conditions
Hazards Identified:
•
Special Flood Hazard Areas
•
Riverine Flooding
•
Canal Embankments
•
Alluvial Fan
•
Transition from Mountain to Urban
Landscape
•
Urban Flooding
•
Sheet Flow Channelized Flow
•
Developments on Fill in Floodplain
Fringe
•
Local Flooding
•
Age of Development and
Infrastructure
•
Under Capacity Infrastructure
•
Un-Delineated Flood Hazards
•
Wash and Basin Vegetation
Maintenance
•
Infill Development
•
Dam and Levee Failure
•
Other Non-Flood Related Hazards
•
Climate Change
•
Wildfires
•
Drought
•
Funding
TAKE A BREAK! 10 MINUTES
12
IMPACTS OF HAZARDS DISCUSSION
13
•
Description of impact hazards identified have on:
•
Life, safety and the need for warning and evacuation
•
Public health, including health hazards to individuals from flood waters and mold
•
Critical facilities and infrastructure
•
City’s economy and major employers
Get this image on: Flickr | License details
Creator: Devon Christopher Adams
Copyright: Devon Christopher Adams
IMPACTS OF HAZARDS DISCUSSION
14
•
Areas that provide natural floodplain functions
•
Description of development, redevelopment, population trends
Images Source: Maricopa Association of Governments
IMPACTS OF HAZARDS DISCUSSION
15
•
Impacts of future flooding conditions on people, property and natural floodplain
functions from:
•
Changes in floodplain development and demographics
•
Development in the watershed
•
Climate change
Get this image on: Flickr | License details
NEXT STEPS:
16
•
Ongoing coordination with FMP Committee
•
Public Survey
•
Public Meetings
•
Next Meeting
•
Wednesday, February 26, 2025 @ 9am – Set Goals
•
Phoenix City Hall - 200 W Washington Street, 85003
Questions?
Next FMP Committee Meeting | February 26, 2025 |9am City of Phoenix, City Hall
BLACK & VEATCH | COMMITTEE MEETING #2 – FY2025 FLOODPLAIN MANAGEMENT PLAN
FEBRUARY 05, 2025
FY2025 Phoenix Floodplain Management Plan (ST83140150)
Committee Meeting #2
February 5, 2025, at 9:00 AM – 11:00 AM
MEETING MINUTES
1. Safety moment – 3 min
2. Overview of FMP Mtg #1: Flood Hazard Identification – 20 min
a. Review CRS and Activity 510
b. Group Discussion of Flood Hazards
3. Impacts of Hazards – Assess the Problem – 15 minutes
a. Life Safety
b. Public Health
c. Critical Facilities and Infrastructure
d. Economy
e. Natural Floodplain Functions
4. Impacts of Hazards During Storms - Assessing the Problem (Step 5) – 30 min
a. Breakout Exercise – Groups to focus on each group’s area
b. Mark up maps and use Worksheet to identify flooding problems
5. Break – 10 min
6. Group Report Out and Discussion – 45 min
a. Description of impact hazards identified have on:
i. Life, safety, health and the need for warning and evacuation
ii. Public health, including health hazards to individuals from flood waters and mold
iii. Critical facilities and infrastructure
iv. City’s economy and major employers
b. Areas that provide natural floodplain functions
c. Description of development, redevelopment, population trends
d. Impacts of future flooding conditions on people, property, and natural floodplain functions from:
i. Changes in floodplain development and demographics
ii. Development in the watershed
iii. Climate change
Discussion:
South Phoenix Group
Description of impacts:
•
Floodplains near South Mountain are not delineated.
•
Golf courses in the area are being redeveloped and increasing impervious areas.
•
Fire station #57 has had flooding along Dobbins
•
Wildfires – The mountain has low brush and fires are typically easily contained.
•
Future SR30 connection freeway may have potential impacts
•
Local flooding
•
County islands, there is a disconnect between city and county and infrastructure isn’t
always continuous.
COMMITTEE MEETING #1
Page 2
2231 East Camelback Road, Suite 350
Phoenix, Arizona 85016
602-381-4400
BLACK & VEATCH | COMMITTEE MEETING #2 – FY2025 FLOODPLAIN MANAGEMENT PLAN
FEBRUARY 05, 2025
•
Other fires along the Salt River as well.
•
Sand and gravel pits
•
Infill flooding
•
A trend of funding being allocated for flooding issues in a reactive manner rather than
proactive. Once the storm passes, there is no motive to allocate funding and it gets put
towards more pressing issues.
Central Phoenix Group
Description of impacts:
•
We identified places on the map where these problems occur.
•
This area includes critical facilities, local flooding, most floodplains are delineated.
•
The whole area is a sheet flow type area, some areas in alluvial fan off mountain range.
•
Economic areas include Biltmore and central/midtown Phoenix area.
•
This area has one levee but is downstream from several dams.
•
A lot of this area was developed before 1980 before retention requirements and were
using older building principles and codes.
•
Much of the flooding is due to lack of infiltration, lack of retention, and small washes
not being properly maintained.
North Phoenix Group
Description of impacts:
•
Local flooding from high intensity storms.
•
The age of the developments, south area developed before certain design standards.
•
Mountain to urban landscape.
•
Developments on natural flood plains
•
Canal embankments, especially with the mountains north of the CAP Canal.
•
Small pockets of un-delineated flood plains
•
Maintenance is an issue.
•
Dams and levees (Phoenix, Bureau of Reclamation, Reach 11, Flood Control District,
Cave Creek, New River)
•
Climate change, wildfires, drought, critical facilities, and funds impact most areas.
Additional Discussion:
•
Above ground reservoirs that could fail and cause problems. Some are considered dams.
•
Private maintenance is an issue. For example, drywells not properly maintained can cause
flooding if they don’t percolate correctly.
•
Redevelopment, and connectivity between different developments.
7. Next Steps – 5 min
a. Public Open Houses – Thursday, March 6 and Tuesday, May 6
8. Adjourn
Next Meeting: Wednesday, February 26, 2025 Phoenix City Hall - 200 W Washington Street, 85003
Committee Meeting #4 – Review Possible Actions
Wednesday, March 19, 2025
Committee Meeting #5 – Draft an Action Plan
Wednesday, April 9, 2025
City of Phoenix Floodplain Management Plan 2025
FMP Committee Meeting #2 – Assess the Problem
Page 1 of 1
Number of flood hazards checked “YES” per watershed by each Group
City Districts
1, 2, and 3
City Districts
4, 5, and 6
City Districts
6 South, 7,
and 8
Flood Hazards
Group 1
Group 2
Group 3
Local Flooding
Transition from Mountains to Urban Landscape
Developments on Fill in Floodplain Fringe
Age of Development
Under Capacity Stormwater Infrastructure
Flood Irrigate Lots
Canal Embankments
Un-delineated Floodplains
Wash and Basin Vegetation Maintenance
Infill Development
Climate Change
Dams
Levees
Additional
Wildfires
Drought
Critical Facilities – Protect airports, canals, hospitals,
utilities, water treatment, fire stations, and police
Funding
City of Phoenix Floodplain Management Plan (FMP) 2025
FMP Committee Meeting #3
February 26, 2025
AGENDA
Safety Moment
Overview of Committee Meeting #2
Refining Identified Hazards and Problems
Overview of 2016 FMP Goals
Discuss & Finalize 2025 FMP Goals
Next Steps
Public outreach efforts
2
SAFETY MOMENT
3
The increase in cellphone use presents many opportunities for distraction.
Distracted walking can lead to unintentional injuries from not paying
attention to your surroundings, such as:
◦
Walking into fixed objects
◦
Being struck by moving vehicles
◦
Walking over an edge or into an open hole
◦
Tripping over an object
◦
Walking under a lifted load
Don’t walk and text and try to use voice options when available.
Pause your conversation when crossing a street or entering a busy area.
Turn down the volume to avoid missing danger signs around you.
Discern which email or text can wait until you reach your destination.
Be courteous of others and don’t text or call while they’re driving or walking.
INTRODUCTIONS
4
OVERVIEW OF CRS ACTIVITY 510 – FLOODPLAIN MANAGEMENT PLAN
5
•
Step 1 – Organize
•
Step 2 – Involve the Public
•
Step 3 – Coordinate
•
Step 4 – Assess the Hazard (FMP Committee Meeting #1)
•
Step 5 – Assess the Problem (FMP Committee Meeting #2)
•
Step 6 – Set Goals (FMP Committee Meeting #3) TODAY’S MEETING
•
Step 7 – Review Possible Actions (FMP Committee Meeting #4)
•
Step 8 – Draft an Action Plan (FMP Committee Meeting #5)
•
Step 9 – Adopt a Plan
•
Step 10 – Implement, Evaluate, and Revise
ASSESS THE HAZARD
•
Worksheet from last meeting
General Hazard Categories
•
Special Flood Hazard Areas
•
Alluvial Fan
•
Urban Flooding
•
Dam and Levee Failure
•
Other Non-Flood Related Hazards
6
Assess the Problem
•
Life Safety
•
Emergency Warning and Response
•
Evacuations
•
Public Health
•
Health Hazards to Individuals – flood waters and mold
•
Critical Facilities and Infrastructure
•
Airports, Water Treatment, Fire and Police, Utilities
•
Schools, Hospitals, Senior Care Facilities
7
ASSESS THE PROBLEM
•
Economy
•
Impacts to Major Employers
•
Natural Floodplain Functions
•
Areas Impacted
•
Environmental and Aesthetic Impacts
•
Development, Redevelopment, and Population
Trends
•
Future Impacts on community, watershed, and natural
resources
•
Future Flooding Conditions
8
DISCUSSION OF 2025
FMP GOALS
Goals are general statements concerning
an aspect of the agency’s desired
ultimate physical, social and/or economic
environment. Goals set the tone for
development decisions in terms of the
citizens' desired quality of life.
Action Items are the specific tasks or
activities necessary to achieve the stated
goals by assigning responsibility to a
specific action.
This Photo by Unknown Author is licensed under CC BY
OVERVIEW OF GOALS FROM
2023 ARIZONA HAZARD MITIGATION PLAN
Overarching goal: Increase resilience throughout the State of Arizona by reducing the vulnerability of
people and property to natural and human- caused hazards.
Objectives:
1. Increase state, tribal, and local government awareness regarding Arizona’s hazards and risks.
2. Promote hazard mitigation throughout Arizona.
3. Ensure the well-being of Arizona’s residents, businesses, and visitors by lessening the impact of
hazards and empowering them to reduce vulnerability through increased public awareness.
4. Reduce the vulnerability of critical facilities and infrastructure to natural and human-caused hazards.
5. Identify and pursue funding sources for hazard mitigation projects.
6. Identify and reduce the number of repetitive loss and severe repetitive loss properties.
7. Identify and reduce vulnerabilities to and from high hazard potential dams and potential
consequences associated with dam incidents.
10
OVERVIEW OF 2016 FMP and 2009/2015/2021 MARICOPA
COUNTY MULTI-JURISDICTIONAL HAZARD MITIGATION PLAN
GOALS
Goals: Reduce or eliminate the risk to people and property from natural hazards.
Goals:
1. Reduce or eliminate risks that threaten life and property in the incorporated, unincorporated, and
tribal jurisdictions within Maricopa County.
2. Reduce risk to critical facilities and infrastructure from natural hazards.
3. Promote hazard mitigation throughout the incorporated, unincorporated, and tribal jurisdictions
within Maricopa County.
4. Increase public awareness of hazards and risk that threaten the incorporated, unincorporated, and
tribal jurisdictions within Maricopa County.
11
OVERVIEW OF 2020 MARICOPA COUNTY FMP GOALS
Overarching goal: Reduce or eliminate the risk to people and property from natural hazards.
Objectives:
1. Transportation and Low Water Crossing Mitigation.
2. Funding Evaluation of Process and Dedicated Resources
3. Education and Technical Resources
4. Managed Open Space
5. Regional Leadership
12
OVERVIEW OF 2020 MARICOPA COUNTY FMP GOALS
Overarching goal: Reduce or eliminate the risk to people and property from natural hazards.
Objectives:
1.
Transportation and Low Water Crossing Mitigation.
a)
The District will work with transportation agencies and the communities to address public concerns on transportation routes
that result in interruptions to normal operating conditions, delays of emergency services, negatively impact the economy,
and pose safety risks due to flooding.
2.
Funding Evaluation of Process and Dedicated Resources
a)
The District shall work in partnership with stakeholders to evaluate its various programs, fiscal opportunities, and funding
processes to assure funds continue to be invested back into the communities.
3.
Education and Technical Resources
a)
The District shall work with stakeholders and local organizations on consistent county-wide technical and educational
materials for flood preparedness with materials available in physical locations as well as electronically.
4.
Managed Open Space
a)
The District shall continue pursuing nature based solutions for flood mitigation, working with stakeholders, to identify and
acquire open space in conjunction with flood control projects.
5.
Regional Leadership
a)
The Flood Control District of Maricopa County shall continue to perform duties as the regional leader in floodplain
management. District shall provide and communicate information, guidelines, and regulations to agencies and communities
throughout Maricopa County and to adjacent Counties.
13
OVERVIEW OF 2025 PIMA COUNTY FMP GOALS
1. Identify, protect, and preserve watercourses and the natural
floodplain function and riparian habitat associated with them, and
restore and enhance them where they have been degraded.
2. Protect, preserve and enhance water resources.
3. Ensure that those who occupy areas within regulatory floodplain and
erosion hazard areas are aware of the consequences of their actions
within those areas.
4. Reduce the need for rescue and relief efforts.
5. Ensure the most effective expenditures of public money for flood
control projects.
14
OVERVIEW OF 2025 PIMA COUNTY FMP GOALS (continued)
6. Prevent flood and erosion damages including ensuring the
operability of critical facilities during flood events.
7. Ensure flexibility for adaptive floodplain management for changing
climate circumstances.
8. Increase regional cooperation and offer interjurisdictional
floodplain management services.
9. Increase beneficial use of stormwater including regional recharge
and urban green spaces.
10. Ensure equitable access to flood mitigation services.
11. Prioritize neighborhood scale beneficial use of stormwater projects
in vulnerable and underserved areas.
15
TAKE A BREAK! – 10 MINUTES
16
DISCUSSION: 2025 FMP GOALS
17
These goals must address all flood-related problems identified in Committee Meeting #2.
Impacts Hazards on the following:
•
Life Safety
•
Public Health
•
Critical Facilities and Infrastructure
•
Economy
•
Natural Floodplain Functions
•
Development, Redevelopment,
and Population Trends
•
Future Flooding Conditions
Hazards Identified:
•
Special Flood Hazard Areas
•
Riverine Flooding
•
Canal Embankments
•
Alluvial Fan
•
Transition from Mountain to Urban
Landscape
•
Urban Flooding
•
Sheet Flow Channelized Flow
•
Developments on Fill in Floodplain
Fringe
•
Local Flooding
•
Age of Development and
Infrastructure
•
Under Capacity Infrastructure
•
Un-Delineated Flood Hazards
•
Wash and Basin Vegetation
Maintenance
•
Infill Development
•
Dam and Levee Failure
•
Other Non-Flood Related Hazards
•
Climate Change
•
Wildfires
•
Drought
•
Funding
GOALS REPORT OUT
18
NEXT STEPS:
19
• Public Meeting – Virtual
• Additional Coordination – Emails to be sent out next week to schedule
• Next Meeting – Review Possible Actions
• Wednesday, March 19, 2025
• Phoenix City Hall - 200 W Washington Street, 85003
Questions?
Next FMP Committee Meeting | March 19, 2025 |9am City of Phoenix City Hall
COMMITTEE MEETING #3
Page 1
BLACK & VEATCH | FMP Committee Mtgs #3 – 2025 FLOODPLAIN MANAGEMENT PLAN
ST83140150, BV 420833 | FEBRUARY 26, 2025
FY2025 Phoenix Floodplain Management Plan (ST83140150)
Committee Meeting #3
February 26, 2025, at 9:00 AM – 11:00 AM
MEETING MINUTES
1. Safety moment
2. Overview of FMP Mtg #2: Assess the Problem
a. Discussion of Identified Hazards and Problems (see PowerPoint presentation for further details)
3. Overview of 2016 FMP Goals
a. Status of 2016 Goals and Action Plan (see PowerPoint presentation for further details)
4. Break
5. 2025 FMP Discussion – Set Goals (Step 6)
a. Discussion of Potential Goals
i. Ali Samiedal:
1. Education for the public, public outreach, exercises to mimic situation after
incident.
2. Education to policy makers and leaders and ongoing education for decision
makers
3. Coordination with other jurisdictions since water doesn’t stay within Phoenix.
a. Improve quality of coordination
4. Funding, securing dedicated funding or looking for opportunities.
5. Identifying project and allocations, including asset management principles and
analysis to identify projects.
ii. Nazar Nabaty:
1. The City’s asset management program will get existing data of stormwater
infrastructure data, will evaluate the conditions, and identify where immediate
action is needed. Over the last 5 years Phoenix had multiple sink holes 9 safety
concerns. So, the other goal is to evaluate capacity and old stuff in downtown,
where it’s all over capacity.
iii. Andrew Hagglund:
1. Prioritize vulnerable communities.
2. Ensure flood mitigation is available.
3. Dedicated funding
4. Protect natural resources.
5. Proactive maintenance
6. Increase safety and awareness.
iv. Kathryn Gross:
1. Expand city maintenance plan
2. Expand funding for flood hazards and mitigation.
3. Take advantage of additional funding
4. Educate and provide assistance to HOA and property owners.
5. Increase/maintain interjurisdictional cooperation.
COMMITTEE MEETING #3
Page 2
BLACK & VEATCH | FMP Committee Mtgs #3 – 2025 FLOODPLAIN MANAGEMENT PLAN
ST83140150, BV 420833 | FEBRUARY 26, 2025
6. Identify flood hazards within communities.
7. Responsible development and re-development on flood related hazards.
v. Nicholas Ramirez:
1. Improve public notification, news, bills, or codes, mail letters, door
hangers.
2. Protecting critical infrastructure, business and residents
3. Protect economy by life and property.
4. Make sure funding of small project assistance funding, grants, are being
used as needed.
5. Natural flood functions
6. Provide knowledge to homeowners and planners of development.
7. Have HOA for city and make sure things are being mitigated.
8. Reviewing plans for how natural water flow is going.
9. Understand max water storage before approval.
a. Need water mitigation plan for 100 year or whatever instead of
just natural areas.
vi. Nazar Nataby:
1. We need to make sure the goals are achievable for the next 5 years and are
within the budget planned.
b. Finalize Goals
6. Next Steps – 5 min
a. Virtual Public Meeting – May 22, 2025
7. Adjourn
Next Meeting:
Committee Meeting #4 – Review Possible Actions
Wednesday, March 19, 2025
Phoenix City Hall - 200 W Washington Street, 85003
Committee Meeting #5 – Draft an Action Plan
Wednesday, April 9, 2025
City of Phoenix Floodplain Management Plan (FMP) 2025
FMP Committee Meeting #4
March 19, 2025
AGENDA
Safety Moment
Overview of Phoenix General Plan
Overview of Committee Meeting #3
Refining and Finalizing Goals
Identify Activities – Review Possible Actions
CRS Step 7
Next Steps
Public Meeting
Outreach
2
ROAD TRIP SAFETY MOMENT
Prepare for your next road trip with the below safety tips:
• Be sure to check the weather conditions locally and your
planned destination
• Inspect tires and torque down lug nuts
• Maintenance your vehicle before long trips
• Pack emergency essentials for people & pets
• flashlight, jumper cables, reflective triangles, first aid
kit, food, water, map, and device chargers
• Keep a blanket or pool towel under you back seat
• Tell family and friends your plans and schedule
• Get plenty of sleep before you trip
• Make sure to drive with a buddy and take turns driving
Photo by Ricky Esquivel
4
CITY OF PHOENIX
2025 GENERAL PLAN
5
6
7
OVERVIEW OF CRS ACTIVITY 510 – FLOODPLAIN MANAGEMENT PLAN
8
•
Step 1 – Organize
•
Step 2 – Involve the Public
•
Step 3 – Coordinate
•
Step 4 – Assess the Hazard (FMP Committee Meeting #1)
•
Step 5 – Assess the Problem (FMP Committee Meeting #2)
•
Step 6 – Set Goals (FMP Committee Meeting #3)
•
Step 7 – Review Possible Actions (FMP Committee Meeting #4) TODAY’S MEETING
•
Step 8 – Draft an Action Plan (FMP Committee Meeting #5)
•
Step 9 – Adopt a Plan
•
Step 10 – Implement, Evaluate, and Revise
REVIEW FMP MEETING # 3 GOALS
•
Public Information
•
Educate the public
•
Improve public notification
•
Educate homeowners and development planners
•
Natural Floodplain Protection
•
Proactive maintenance
•
Protect natural floodplain functions
•
Property Protection
•
Provide assistance to HOA & property owners
•
Identify flood hazards in communities
•
Protecting critical infrastructure
•
Regulatory Standards
•
Max water storage, reviewing natural flows
•
Educating policy makers and leaders
•
Funding
•
Expand funding for flood hazards and mitigation
•
Securing dedicated funding
9
FINALIZE GOALS
•
Protect People, Property, and Natural Floodplain Functions
•
Protect Critical Infrastructure and Facilities
•
Proactive Maintenance and Preventative Measures
•
Education Public, City Leaders, and Policy Makers
•
Coordination with Other Jurisdictions
•
Funding
10
STEP 7 – REVIEW
POSSIBLE ACTIONS
•
Review of a wide range of activities to
ensure all possible measures are
explored
•
Not just the traditional approaches of
flood control, acquisition, and
regulation of land use
•
Discuss Pros and Cons for Different
Activities
•
Brainstorm all possible activities
11
2016 Phoenix FMP
Action Items
• Administrative
• Program
• Public Information
12
2021 Maricopa County Hazard Mitigation Plan
Action Plan
•
Regulatory Standards
•
Property Protection
•
Protection of Natural Floodplain Function
•
Emergency Services Activities
•
Structural Projects
•
Public Information Activities
•
Fiscal Capabilities
13
MARICOPA AND PIMA COUNTY FMP ACTION ITEMS
14
TAKE A BREAK! – 10 MINUTES
15
REVIEW POSSIBLE ACTIONS
BREAK OUT – 30 MINUTES
16
Goals:
•
Protect People, Property, and Natural
Floodplain Functions
•
Protect Critical Infrastructure and Facilities
•
Proactive Maintenance and Preventative
Measures
•
Education Public, City Leaders, and Policy
Makers
•
Coordination with Other Jurisdictions
•
Funding
Action Item Categories:
•
Preventative
•
Property Protection
•
Natural Resource Protection
•
Emergency Services
•
Structural Projects
•
Public Information
Review Possible Actions – Step 7
• Identify Activities
• Preventative
• Property Protection
• Natural Resource Protection
• Emergency Services
• Structural Projects
• Public Information
17
NEXT STEPS:
18
• Public Meeting – Virtual – May 22nd
• Outreach – Sunnyslope and Laveen
• Next (& Last) Meeting
• Wednesday, April 9, 2025
• Phoenix City Hall - 200 W Washington Street, 85003
Questions?
Next FMP Committee Meeting | April 9, 2025 |9am City of Phoenix City Hall
COMMITTEE MEETING #4
Page 1
BLACK & VEATCH | FMP Committee Mtg #4 – 2025 FLOODPLAIN MANAGEMENT PLAN
ST83140150, BV 420833 | March 19, 2025
FY2025 Phoenix Floodplain Management Plan (ST83140150)
Committee Meeting #4
March 19, 2025, at 9:00 AM – 11:00 AM
MEETING MINUTES
1. Safety moment – Road Trip Safety
2. Overview of Phoenix General Plan
3. Overview of FMP Mtg #3: Set Goals
a. Finalize Goals Language
i. Expand on funding and be more specific.
•
Funding should be proactive instead of reactive.
ii. Manny Patel – Add language that includes “present/future”.
iii. Nazar Nataby – change wording to “mitigation and planning” instead of protecting.
4. Step 7 – Review Possible Actions
a. Previous Phoenix, Maricopa County, and Pima County Goals (See Presentation slides for details)
5. Break
6. Breakout – Identify Possible Activities
7. 2025 FMP Discussion - Identify Activities – Review Possible Actions (Step 7)
a. Group 1
i. Educate the Public, Policy Makers, and City
•
Posting public meetings, informing the public of dangers and upcoming plans.
•
City members should attend HOA meetings.
ii. Coordination with Other Jurisdictions
•
Training and inviting other agencies.
•
Hosting joint public and agency meetings.
•
Make regulations more “friendly” and explain the why behind them.
iii. Protect People, Property and Natural Resources
•
Marking flood areas with survey equipment to install safety measures.
iv. Protect Critical Infrastructure and Facilities
•
Make sure critical facilities are protected.
v. Maintenance and Preventative Measures
•
Maintenance plans
•
Accountability
•
Pre vs Post failure costs and efforts
b. Group 2
i. Educate the Public, Policy Makers, and City
•
Flyers and websites
•
Develop vegetation management hazards.
•
Attend neighborhood meetings, and home and garden shows.
•
Educate council and encourage them to educate their constituents.
COMMITTEE MEETING #4
Page 2
BLACK & VEATCH | FMP Committee Mtg #4 – 2025 FLOODPLAIN MANAGEMENT PLAN
ST83140150, BV 420833 | March 19, 2025
ii. Coordination with Other Jurisdictions
•
Make sure agencies such as ADOT, CAP, FEMA, DEMA are on the same page
and have the latest and greatest information.
iii. Protect People, Property and Natural Resources
•
Use information as a way to protect.
•
Evaluate and update standards.
iv. Protect Critical Infrastructure and Facilities
•
Maintain database of critical facilities.
v. Maintenance and Preventative Measures
•
Continue and expand annual inspections and repairs and check that
other agencies are performing their maintenance.
•
Letting people know how much city is maintaining.
vi. Funding
•
Nonprofit assistance
•
Expand impact fee
c. Group 3
i. Educate the Public, Policy Makers, and City
•
Overview of design flows, investigate where higher restrictions are
needed.
•
Implement something for hill bottom developments where flooding is
more likely.
•
Requirements for retaining more onsite.
ii. Protect People, Property and Natural Resources
•
Invest in green stormwater infrastructure and infiltration methods.
•
Implement ways to slow down flows.
•
Keeping natural washes functioning naturally.
iii. Maintenance and Preventative Measures
•
Proper maintenance of basins and retention ponds
•
Using natural vegetation to slow flows
iv. Funding
•
Dedicated funding
•
Tucson or Pima has a stormwater infrastructure funds.
•
The City should not rely on piecemeal funding, there needs to be
permanent funding
d. Group 4
i. Educate the Public, Policy Makers, and City
•
Community advocate
•
Advertising for elderly
ii. Protect People, Property and Natural Resources
•
Perform flood plain delineation study.
•
Letting people know they may be at risk.
iii. Maintenance and Preventative Measures
•
Maintenance on drywells and require HOAs to prove the drywells work.
•
Easy way to report maintenance issues.
COMMITTEE MEETING #4
Page 3
BLACK & VEATCH | FMP Committee Mtg #4 – 2025 FLOODPLAIN MANAGEMENT PLAN
ST83140150, BV 420833 | March 19, 2025
8. Next Steps
a. Virtual Public Meeting – May 22, 2025
b. Stakeholder Outreach
9. Adjourn
Final Meeting:
Committee Meeting #5 – Draft an Action Plan
Wednesday, April 9, 2025
Phoenix City Hall - 200 W Washington Street, 85003
City of Phoenix Floodplain Management Plan (FMP) 2025
FMP Committee Meeting #5
April 9, 2025
AGENDA
Safety Moment
Overview of Meetings #1-4
Evaluate Action Items
Next Steps
2
SAFETY MOMENT – ALLERGY SEASON
3
Symptoms:
Sneezing, itchy eyes, congestion, shortness of breath, wheezing and coughing.
Common Allergens:
•
Tree pollen, Grass pollen, Ragweed pollen, and Mold.
Some factors that fan affect allergy season:
•
Temperature, Rain, Locations with different allergy seasons
Reduce your exposure to allergy triggers:
•
Monitor pollen counts and plan activities accordingly
•
Wash clothes and shower after beings outside
•
Close doors and windows
•
Air Filters (HEPA), portable air purifiers
OVERVIEW OF CRS ACTIVITY 510 – FLOODPLAIN MANAGEMENT PLAN
4
•
Step 1 – Organize
•
Step 2 – Involve the Public
•
Step 3 – Coordinate
•
Step 4 – Assess the Hazard (FMP Committee Meeting #1)
•
Step 5 – Assess the Problem (FMP Committee Meeting #2)
•
Step 6 – Set Goals (FMP Committee Meeting #3)
•
Step 7 – Review Possible Actions (FMP Committee Meeting #4)
•
Step 8 – Draft an Action Plan (FMP Committee Meeting #5) TODAY’S MEETING
•
Step 9 – Adopt a Plan
•
Step 10 – Implement, Evaluate, and Revise
FMP Mtg #1:
Assess the Hazard
•
Special Flood Hazard Areas
•
Riverine Flooding
•
Canal Embankments
•
Alluvial Fan
•
Transition from Mountain to Urban Landscape
•
Urban Flooding
•
Sheet Flow Channelized Flow
•
Developments on Fill in Floodplain Fringe
•
Local Flooding
•
Age of Development and Infrastructure
•
Under Capacity Infrastructure
•
Un-Delineated Flood Hazards
•
Wash and Basin Vegetation Maintenance
•
Infill Development
5
Additional Hazards for Consideration
•
Dam and Levee Failure
•
Other Non-Flood Related Hazards
•
Climate Change
•
Wildfires
•
Drought
•
Funding
6
FMP Mtg #2:
Assess the Problem
•
Life Safety
•
Emergency Warning and Response
•
Evacuations
•
Public Health
•
Health Hazards to Individuals – flood waters and mold
•
Critical Facilities and Infrastructure
•
Airports, Water Treatment, Fire and Police, Utilities
•
Schools, Hospitals, Senior Care Facilities
7
•
Economy
•
Impacts to Major Employers
•
Natural Floodplain Functions
•
Areas Impacted
•
Environmental and Aesthetic Impacts
•
Development, Redevelopment, and Population
Trends
•
Future Impacts on community, watershed, and natural
resources
•
Future Flooding Conditions
8
FMP Mtg #2:
Assess the Problem
FMP MTG #3
SET GOALS
•
Educate Public, Policy Makers, and City Leaders on Stormwater and Floodplain
Management and Risks
•
Coordinate with Other Jurisdictions and Agencies to Mitigate Flooding Hazards and
Improve Emergency Response
•
Protect People, Property and Natural Resources from the Dangers of Flood Hazards
•
Protect Critical Infrastructure and Facilities to Ensure Operation during and after Flood
Events
•
Establish Proactive Maintenance and Preventative Measures for Stormwater
Infrastructure
9
EVALUATE ACTION ITEMS
10
Educate Public, Policy Makers, and City Leaders on Stormwater and Floodplain Management and Risks
1. Present annually at a City of Phoenix Council Meeting on state of City’s stormwater and floodplain.
2. Create an annual stormwater and floodplain management workshop for City leaders, Councilmembers, and
Neighborhood Services to help with education and outreach.
3. Develop flyers, CRS Annual Outreach Letter, and a CRS specific webpage for use by the public, City leaders, policy
makers, and the City’s Neighborhood Services department.
4. Post at least once per month a stormwater, floodplain, or flood insurance related topic on the City’s social media
platforms.
5. Provide stormwater section bi-annually within the City’s water bill for stormwater and floodplain outreach and
education purposes.
6. Attend/Present at four neighborhood associations meetings, festivals, or home & garden shows per year to
provide information to the public on recent, current, and future stormwater and floodplain projects and the
importance of flood insurance.
7. Place signage at City dams to educate the public of the presence of the structure, the need for the structure, and
risks.
8. Annual outreach to repetitive loss areas.
PREVENTATIVE | PROPERTY PROTECTION | NATURAL RESOURCE PROTECTION
EMERGENCY SERVICES | STRUCTURAL PROJECTS | PUBLIC INFORMATION
CRS ACTION
ITEM CATEGORIES
11
Coordinate with Other Jurisdictions and Agencies to Mitigate Flooding Hazards and Improve Emergency Response
9. Hold annual dam safety and flood response exercises and invite other agencies to participate.
10. Coordinate with the National Weather Service and National Oceanic and Atmospheric Administration for
updates to weather forecasting and warnings.
11. Send at least one City staff to a FEMA training/workshop annually for emergency response or floodplain
management as credited by CRS Activity 360 – Advisor Training (TNG).
12. Establish a network of Continuously Operating Reference Stations (CORS) throughout the City to provide
overlapping coverage to support increased detail in surveys for development and public infrastructure projects.
EVALUATE ACTION ITEMS
PREVENTATIVE | PROPERTY PROTECTION | NATURAL RESOURCE PROTECTION
EMERGENCY SERVICES | STRUCTURAL PROJECTS | PUBLIC INFORMATION
CRS ACTION
ITEM CATEGORIES
12
Protect People, Property and Natural Resources from the Dangers of Flood Hazards
13. Hold an annual webcast to provide recommendations for proper vegetation maintenance and flood
preparedness.
14. Publicize the Flood Concerns Customer Self-Reporting on City’s 311 App and Webpage.
15. Require new developments to preserve natural drainage corridors.
16. Promote Green Infrastructure and Low Impact Development to mitigate flooding risks.
17. Complete major projects within the current 5-year Capital Improvement Program – Paradise Ridge Drainage
Improvements; Drainage Improvements: 20th Street between Winchcomb Drive and 19th Way; Storm Drain
Replacement Study; Laveen Flood Mitigation; and Hohokam Drainage Program.
EVALUATE ACTION ITEMS
PREVENTATIVE | PROPERTY PROTECTION | NATURAL RESOURCE PROTECTION
EMERGENCY SERVICES | STRUCTURAL PROJECTS | PUBLIC INFORMATION
CRS ACTION
ITEM CATEGORIES
13
Protect Critical Infrastructure and Facilities to Ensure Operation during and after Flood Events
18. Identify and map critical infrastructure and facilities within the City of Phoenix.
19. Evaluate flood risks for critical infrastructure and facilities.
20. Provide flood fight materials at/near critical infrastructure and facilities based on flood risk.
21. Annually update database of critical infrastructure and facilities.
22. Establish or Update Emergency Action Plans to address flood response scenarios for City-owned critical
infrastructure and facilities.
23. Update Emergency Action Plans annually for the City’s flood control dams.
24. Require elevation or floodproofing of any new or improvements to existing critical infrastructure or facilities.
EVALUATE ACTION ITEMS
PREVENTATIVE | PROPERTY PROTECTION | NATURAL RESOURCE PROTECTION
EMERGENCY SERVICES | STRUCTURAL PROJECTS | PUBLIC INFORMATION
CRS ACTION
ITEM CATEGORIES
14
Establish Proactive Maintenance and Preventative Measures for Stormwater Infrastructure
25. Documentation of maintenance occurring at problematic areas throughout the year. (ST. Maint.)
26. Establish requirements and reporting on City-owned drywell maintenance. (ST Maint)
26. Publicize City’s 311 App and Webpage for reporting maintenance issues.
27. Publicize the City’s maintenance procedures and work completed each year (social media post and/or water
bill).
28. Evaluate current stormwater and floodplain requirements, guidelines, regulations, codes, and design manuals
for updates.
29. Evaluate and update Building Codes on a routine basis (at least every 5 years).
30. Develop a publicly facing vegetation maintenance guide for private use for wash corridors, storm drain inlets
and outlets, and stormwater storage basins.
31. Evaluate and document City-owned stormwater infrastructure for maintenance responsibilities.
EVALUATE ACTION ITEMS
PREVENTATIVE | PROPERTY PROTECTION | NATURAL RESOURCE PROTECTION
EMERGENCY SERVICES | STRUCTURAL PROJECTS | PUBLIC INFORMATION
CRS ACTION
ITEM CATEGORIES
15
Utilize Public Funding in the Most Effective Manner for Stormwater and Floodplain Management
33. Utilize General Obligation Bond funding to mitigate flooding risks.
34. Apply for grants through state and federal agencies to reduce the burden on the City for stormwater and
floodplain management projects.
35. Continue partnership with the Flood Control District of Maricopa County and the Small Projects Assistance
Program.
36. Evaluate the need and practicality of a stormwater utility fee to establish a dedicated funding resource for the
City’s stormwater and floodplain needs.
37. Evaluate the need to expand impact fees.
EVALUATE ACTION ITEMS
PREVENTATIVE | PROPERTY PROTECTION | NATURAL RESOURCE PROTECTION
EMERGENCY SERVICES | STRUCTURAL PROJECTS | PUBLIC INFORMATION
CRS ACTION
ITEM CATEGORIES
16
ACTION PLAN (EXAMPLE LAYOUT)
Preventative
Property Protection
Natural Resource Protection
Emergency Services
Structural Projects
Public Information
Deadline
FMP Goal 1: Educate Public, Policy Makers, and City Leaders on Stormwater and Floodplain Management and Risks
Ref #
Action Items
FMP Activity Categories
Priority
Responsible
Party
Funding
Source
NEXT STEPS:
17
• Review of Draft FMP – Late May through June 2025
• Public Meeting (virtual) – May 22nd
• Neighborhood Presentations – Laveen (April 23)
• FMP Implementation, Evaluation, and Revision (Step 10)
Thank you for your time
and support!
Questions?
BLACK & VEATCH | COMMITTEE MEETING #5 – 2025 FLOODPLAIN MANAGEMENT PLAN
APRIL 09, 2025
FY2025 Phoenix Floodplain Management Plan (ST83140150)
Committee Meeting #5
April 9, 2025, at 9:00 AM – 11:00 AM
MEETING MINUTES
1. Safety moment – Allergy Season
2. Overview of Meetings 1 – 4.
a. Review of Hazards and Problems Identified
b. Review of Updated FMP Goals
i. Educate Public, Policy Makers, and City Leaders on Stormwater and
Floodplain Management and Risks
ii. Coordinate with Other Jurisdictions and Agencies to Mitigate Flooding
Hazards and Improve Emergency Response
iii. Protect People, Property and Natural Resources from the Dangers of
Flood Hazards
1. Nazar Nabaty: Use reduce the risk instead of "protect" on the
phrasing of goals.
2. Nick Ramirez: Maybe “public safety awareness to mitigate or
reduce risk"
iv. Protect Critical Infrastructure and Facilities to Ensure Operation during
and after Flood Events
v. Establish Proactive Maintenance and Preventative Measures for
Stormwater Infrastructure
vi. Utilize Public Funding in the Most Effective Manner for Stormwater and
Floodplain Management
3. Action Items Discussion (Step 8)
a. CRS Manual Action Item Categories
i. Preventative
ii. Property Protection
iii. Natural Resource Protection
iv. Emergency Services
v. Structural Projects
vi. Public Information
b. Group Discussion of Action Item by Goals
Goal 1: Educate Public, Policy Makers, and City Leaders on Stormwater and
Floodplain Management and Risks
• These action items notify the same people a lot. The workshop should be
held prior to the State of the State Address.
• Stating CRS specific webpage
COMMITTEE MEETING #5
Page 2
BLACK & VEATCH | COMMITTEE MEETING #5 – 2025 FLOODPLAIN MANAGEMENT PLAN
APRIL 09, 2025
• Action Items 4 & 6: Combine these and make it quarterly.
• Put social media information in water bill.
• Be more specific on the attendance at garden shows or festivals.
• Signage should be expanded beyond City dams.
• Use County’s resources for new, radio and TV ads.
• Action Item 1: Add “program” at the end.
• Action Item 8: Add “provide” to the beginning.
• Action Item 2: This should be reworded; the workshops should include
hands-on and educational sections.
Goal 2: Coordinate with Other Jurisdictions and Agencies to Mitigate Flooding
Hazards and Improve Emergency Response
• Action Item 10: Make this more inclusive.
• Add clarification like “continue to participate” for things the City is
already doing
• Action Item 11: State “have staff attend” instead of “send”. Remove “as
credited”.
• Action Item 11: FEMA may not be funded, maybe do AFMA Conference.
There need to be alternatives for the scenario where grants and funding
are not available.
• Action Item 12: ADWR opened new stations, maybe city coordinates with
them to use the COR station being developed. Maybe add a few more.
Goal 3: Protect People, Property and Natural Resources from the Dangers of
Flood Hazards
• Action Item 13: Instead of webcast alone, it should be in person.
• Item 13 - encourage more than webcast, direct outreach, email, social
media, media.
• Action Item 13: YouTube tutorial on maintenance
• Action Item 15 & 16: Combine these two items.
• Action Item 15: Use “evaluate” instead of “require” .
• Item 16 - include “promote, incentivize and encourage”.
• Action Item 17: Update the public on the projects. Instead of “complete
major projects” say “show major progression” or something similar. Use
QR codes for people to sign up for project updates.
Goal 4: Protect Critical Infrastructure and Facilities to Ensure Operation during
and after Flood Events
• Action Item 23: Review and determine if updates are needed.
COMMITTEE MEETING #5
Page 3
BLACK & VEATCH | COMMITTEE MEETING #5 – 2025 FLOODPLAIN MANAGEMENT PLAN
APRIL 09, 2025
Goal 5 & 6: Establish Proactive Maintenance and Preventative Measures for
Stormwater Infrastructure & Utilize Public Funding in the Most Effective
Manner for Stormwater and Floodplain Management
• Action Item 25: City should have an internal priority list.
• Action Item 26A: clarify the requirements.
• There are new MS4 post construction requirements for new drywells.
There are more requirements related to confirming maintenance.
• Action Item 34: There may be no federal grants.
• Action Item 25: Include the cost of maintenance for justifying a project.
• Action Item 27: Put project updates on webpage.
• Action Item 27: Reword. City crew procedures should stay private. Maybe
a separate public procedure for HOAs would be public. Clarify this item.
• Action Item 30: Clarify how this would be distributed. This may be an
opportunity to coordinate with Army Corp.
• Action Item 31: Include evaluating and documenting recommended
recurrence intervals for maintenance.
4. Next Steps
a. Review of Draft FMP
b. Public Meeting (virtual) – May 22nd
c. Neighborhood Presentations – Laveen (April 23)
d. FMP Implementation, Evaluation, and Revision (Step 10)
5. Adjourn
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
D-1
Appendix D. Public Meetings
APPENDIX D. PUBLIC MEETINGS
E
TE
T
E
Phoenix.gov
treets Meetings
Thursday, May 22 at 6:00 PM
Virtual (join by computer or phone)
Virtual (únase por computadora o teléfono)
VIRTUAL PUBLIC MEETING NOTICE
Jueves 22 de mayo a las 6:00 PM
Floodplain Management Plan
Plan de Gestión de Llanuras Inundables
AVISO DE REUNIÓN PÚBLICA VIRTUAL
This property address is located in or near a location that
could be affected by flooding activity. The City of Phoenix is
hosting an educational virtual meeting on May 22, 2025 at
6:00 p.m. to invite your input as the city updates its
Floodplain Management Plan. Community input is key to
providing a well-rounded plan to mitigate against flooding
and protect people, property, and the natural environment.
Learn more and register to attend the May 22, 2025
meeting by scanning the QR code.
La dirección de esta propiedad se encuentra en o cerca de
una zona con riesgo de inundación. La Ciudad de Phoenix
organizará una reunión virtual el 22 de mayo de 2025 a las
6:00 p.m. para solicitar su opinión mientras la ciudad
actualiza su Plan de Gestión de Llanuras Inundables. La
opinión de la comunidad es fundamental para desarrollar un
plan integral para mitigar las inundaciones y proteger a las
personas, las propiedades y el medio ambiente. Obtenga
más información e inscríbase para asistir a la reunión del 22
de mayo de 2025 escaneando el código QR.
If you require reasonable accommodations for this process, please contact the project hotline. This notice
can be made available in an alternate format upon request by calling 602-262-6284.
Si necesita adaptaciones razonables para este proceso, comuníquese con la línea del proyecto.
Este aviso puede estar disponible en un formato alternativo a pedido llamando al 602-262-6284.
Street Transportation Department
200 West Washington Street, 5th Floor
Phoenix, Arizona 85003
Public Meeting promotion
•3,757 postcards mailed to properties in flood risk boundary
•5-6-25 1 post to NextDoor
•5-11-25 1 each Instagram, Facebook and X posts
•5-16-25 1 each Facebook and X posts
•5-20-25 1 Instagram post
FMP Public Mee ng Social Media Posts – Examples from Instagram and NextDoor
Page 1 of 2
FMP Public Mee ng Social Media Posts – Examples from Instagram and NextDoor
Page 2 of 2
5/23/2025
1
2025 FLOODPLAIN MANAGEMENT PLAN
Public meeting:
May 22, 2025
INTERPRETER
ESCUCHAR EN ESPAÑOL
Marque 602-534-1000,
luego el número de
reunión, 57271, y luego
apriete el #.
1
2
5/23/2025
2
INTERACTING ON WEBEX
3
CITY ENGINEER WELCOME
ERIC FROBERG
4
3
4
5/23/2025
3
PROJECT TEAM
Nazar Nabaty – Project Manager, Floodplain Administrator, and
Floodplain Management Group Manager
Nick Ramirez – Principal Engineering Tech
Matt Hann – Consultant (Black & Veatch)
Zaria Sanchez – Consultant (Black & Veatch)
5
MEETING AGENDA
• National Flood Insurance Program
• Community Rating System
• What is the Floodplain Management Plan?
• Floodplain Management Plan Development
• Timeline
• How can you get involved?
• Q&A
6
5
6
5/23/2025
4
NATIONAL FLOOD
INSURANCE PROGRAM (NFIP)
• National Flood Insurance Act of 1968
– Reducing future flood damage
– Protecting property owners
• Mapping
• Flood Insurance
• Regulations
• Community Rating System (CRS)
7
COMMUNITY RATING SYSTEM
(CRS)
• Voluntary Incentive Program
• Above and beyond the NFIP minimum requirements
• Incentives for flood insurance premiums
• Phoenix - Class 5 Community (25% Flood Insurance Premium Reduction)
8
7
8
5/23/2025
5
9
FLOODPLAIN MANAGEMENT PLAN (FMP)
OVERVIEW
• Part of the Community Rating System (CRS)
• Identifies flood hazards
• Sets goals
• Provides recommendations to address the City’s
vulnerability to flooding
• Updates existing Floodplain Management Plan
– As required by Community Rating System
10
9
10
5/23/2025
6
FLOODPLAIN MANAGEMENT PLAN
(FMP) COMMITTEE
• Development partners:
• Arizona Department of Transportation
• Arizona Department of Water Resources
• Arizona State Land Department
• Flood Control District of Maricopa County
• Maricopa County Department of
Emergency Management
• National Weather Service
• City of Phoenix Residents
11
FLOODPLAIN MANAGEMENT
PLAN (FMP) DEVELOPMENT STEPS
• Step 1 – Organize
• Step 2 – Involve the Public
• Step 3 – Coordinate
• Step 4 – Assess the Hazard (FMP Committee Meeting #1)
• Step 5 – Assess the Problem (FMP Committee Meeting #2)
• Step 6 – Set Goals (FMP Committee Meeting #3)
• Step 7 – Review Possible Actions (FMP Committee Meeting #4)
• Step 8 – Draft an Action Plan (FMP Committee Meeting #5)
• Step 9 – Adopt a Plan
• Step 10 – Implement, Evaluate, and Revise
12
11
12
5/23/2025
7
2025 FLOODPLAIN MANAGEMENT
PLAN (FMP) HAZARDS IDENTIFIED
• Special Flood Hazard Areas (Floodplains)
• Transitions from Mountain to Urban
• Dams and Levees
• Other Non-Flood Related Hazards
• Wildfires
• Drought
• Funding
13
2025 FLOODPLAIN MANAGEMENT
PLAN (FMP) GOALS
• Educate public, policy makers, and City leaders on
stormwater and floodplain management and risks
• Coordinate with other jurisdictions and agencies to mitigate
flooding hazards and improve emergency response
• Reduce the danger of flood hazards to people, property,
critical infrastructure/facilities, and natural resources
14
13
14
5/23/2025
8
2025 FLOODPLAIN MANAGEMENT
PLAN (FMP) GOALS
• Enhance proactive maintenance and preventive measures
for stormwater infrastructure
• Seek additional public funding opportunities to support
stormwater and floodplain management
15
2025 FLOODPLAIN MANAGEMENT
PLAN (FMP) DRAFT ACTION ITEMS
• Action items support the FMP Goals through the following categories:
• Preventive (Regulatory & Maintenance)
• Property Protection
• Natural Resource Protection
• Emergency Services
• Structural Projects (e.g., Storm drains, channels)
• Public Information
16
15
16
5/23/2025
9
2025 FLOODPLAIN MANAGEMENT PLAN (FMP)
EXAMPLE DRAFT ACTION ITEMS
• Preventive (Regulatory &
Maintenance)
• Continue frequent review of
regulations and requirements for
updates.
• Evaluate City-owned storm drain
infrastructure for maintenance,
repair, and rehabilitation needs.
17
2025 FLOODPLAIN MANAGEMENT PLAN (FMP)
EXAMPLE DRAFT ACTION ITEMS
• Property Protection
• Public outreach and education.
• Provide additional information
and guidelines for drainage
infrastructure maintenance on
private property.
18
17
18
5/23/2025
10
2025 FLOODPLAIN MANAGEMENT
PLAN (FMP) DRAFT ACTION ITEMS
• Natural Resource Protection
• Promote the preservation of natural
drainage corridors in new
developments.
• Promote the use of Green
Stormwater Infrastructure and Low
Impact Development (examples:
bioswales, infiltration basins,
detention/retention systems).
19
2025 FLOODPLAIN MANAGEMENT
PLAN (FMP) DRAFT ACTION ITEMS
• Emergency Services
• Continue to conduct annual dam
safety/flood response exercises.
• Continue ongoing coordination with
other local and regional agencies for
flood warnings and emergency
response.
20
19
20
5/23/2025
11
2025 FLOODPLAIN MANAGEMENT
PLAN (FMP) DRAFT ACTION ITEMS
• Structural Projects (e.g., Storm drains,
channels)
• Complete stormwater and flood
reduction projects within the
current Capital Improvement Plan,
General Obligation Bond, and
American Rescue Plan Act
(ARPA).
21
2025 FLOODPLAIN MANAGEMENT
PLAN (FMP) DRAFT ACTION ITEMS
• Public Information
• Annual stormwater and floodplain
management workshop.
• Utilize social media to post about
stormwater and floodplain
management education.
22
21
22
5/23/2025
12
FLOODPLAIN MANAGEMENT PLAN
(FMP) TIMELINE
23
January 2025
• Start of FMP
Development
May/June 2025
• Draft FMP
Development
June/July
2025
• FMP
Public
Review
Period
July/Aug
2025
• Finalize
FMP
Sept 2025
• City
Council
Adoption
of 2025
FMP
HOW CAN YOU GET INVOLVED
AND PROVIDE FEEDBACK…?
24
• FMP Public Survey (https://www.surveymonkey.com/r/QDP2WZ3)
• City of Phoenix Floodplain Management Plan Webpage
(https://phoenix.gov/streets/fmp)
FMP Public
Survey
City’s FMP
Webpage
23
24
5/23/2025
13
PUBLIC SURVEY ACCESS
25
https://phoenix.gov/streets/fmp
QUESTIONS…?
26
FMP Public
Survey
City’s FMP
Webpage
https://phoenix.gov/streets/fmp
https://www.surveymonkey.com/r/QDP2WZ3
25
26
Phoenix Floodplain Management Plan
May 22, 2025 Public Meeting
Registration / Attendance List
Name
Wish to Speak?
Valerie Denny
No
Mary Hayes
No
Shelly Jamison
Yes
Joan Petersen
No
Donald Sterusky
Evan Pochert
No
David Bell
No
Lisa Cooper
Yes
Stanley Gering
No
Carrie Cook
Yes
Ruben Sepulveda
Lisa Knight
No
Annette Petzel
No
Antonio Payan
No
Julie Robbins
Monica Sandoval
No
Jeffery Wardlaw
No
Stephen Rowe
No
Stephen Jennings
Yes
Fred Goldman
No
Kimberly Villabon
Yes
James Kahler
No
Rachel Hernandez
No
Luus Saenz
No
Maribel Mounts
Yes
Julian Espinosa
No
Ynez Chacon
No
Sarah OCampo
No
Robert Medland
No
Susan Medland
No
Derek SHank
No
Julianne Birdt
marilyn szabo
Yes
Peter Flynn
No
Christine Luksik
No
Alaina Montanaro
No
John Regester
No
Ted Crowley
No
Kevin C James
Israel Elizalde
Frances Navarro
Yes
Kathryn Gross
No
Norma Johnson
No
bob eichinger
No
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
E-1
Appendix E. Progress Report Template
APPENDIX E. PROGRESS REPORT TEMPLATE
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
E-2
Appendix E. Progress Report Template
EXAMPLE PROGRESS REPORT
City of Phoenix, Arizona
Floodplain Management Plan
Annual Progress Report
Reporting Period: (Insert reporting period)
Background: The City of Phoenix developed a floodplain management plan (2025 FMP) to reduce risk from
flooding by identifying resources, information, and strategies for risk reduction. To prepare the 2025 FMP,
the City organized resources, assessed risks from flooding, developed planning goals and objectives,
reviewed mitigation alternatives, and developed an action plan to address probable impacts from floods.
Stafford Act. The 2025 FMP can be viewed on-line at:
INSERT WEBPAGE
Summary Overview of the Plan’s Progress: The performance period for the 2025 FMP began on ____, 2025,
with the final approval of the plan by FEMA. The initial performance period will be 5 years, with an
anticipated update to the plan to occur before ______, 2030. As of this reporting period, the performance
period is considered to be __% complete. The 2025 FMP has targeted 79 floodplain management actions
to be pursued during the 5-year performance period. As of the reporting period, the following overall
progress can be reported:
•
__ out of __ actions (__%) were reported as being in progress toward completion.
•
__ out of __ actions (__%) were reported as being complete.
•
__ out of __ actions (___%) were reported as ongoing capabilities that are now completed on a
regular or annual basis.
•
__ out of __ actions (___%) reported no action taken.
Purpose: The purpose of this report is to provide an annual update on the implementation of the action
plan identified in the 2025 FMP. The objective is to ensure that there is a continuing and responsive
planning process that will keep the 2025 FMP dynamic and responsive to the needs and capabilities of the
City and stakeholders. This report discusses the following:
•
Flood events that have occurred within the last year
•
Changes in risk exposure within the City of Phoenix
•
Mitigation success stories
•
Review of the action plan
•
Changes in capabilities that could impact plan implementation
•
Recommendations for changes/enhancement.
The Floodplain Management Plan FMP Committee: The Floodplain Management Plan FMP Committee,
made up of stakeholders within the City of Phoenix, reviewed and approved this progress report at its
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
E-3
Appendix E. Progress Report Template
annual meeting held on _____, 202_. It was determined through the 2025 FMP’s development process that
a FMP Committee would remain in service to oversee maintenance of the 2025 FMP. At a minimum, the
FMP Committee will provide technical review and oversight on the development of the annual progress
report. It is anticipated that there will be turnover in the membership annually, which will be documented
in the progress reports. For this reporting period, the FMP Committee membership is as indicated in Table
E-1.
Table E-1. FMP Committee Members
Name
Title
Jurisdiction/Agency
Flood Events: During the reporting period, there were __ flood events in the City of Phoenix that had a
measurable impact on people or property. A summary of these events is as follows:
•
__________________________
•
__________________________
Changes in Risk Exposure: (Insert brief overview of any flood event in the City of Phoenix that changed the
probability of occurrence of flooding as presented in the FMP2020)
Mitigation Success Stories: (Insert brief overview of mitigation accomplishments during the reporting period)
Review of the Action Plan: Table E-2 reviews the action plan, reporting the status of each action. Reviewers
of this report should refer to the 2025 FMP for more detailed descriptions of each action and the
prioritization process.
Address the following in the “status” column of the following table:
•
Was any element of the action carried out during the reporting period?
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
E-4
Appendix E. Progress Report Template
•
If no action was completed, why?
•
Is the timeline for implementation for the action still appropriate?
•
If the action was completed, does it need to be changed or removed from the action plan?
Table E-2. Action Plan Matrix
Action
Take?
(Yes or No)
Timeline
Priority
Status
(X, O, ✓)
Comment
Action #__—______________________[description]
Action #__—______________________[description]
Action #__—______________________[description]
Action #__—______________________[description]
Action #__—______________________[description]
Action #__—______________________[description]
Action #__—______________________[description]
Action #__—______________________[description]
Action #__—______________________[description]
Action #__—______________________[description]
Action #__—______________________[description]
Action #__—______________________[description]
Action #__—______________________[description]
Action #__—______________________[description]
Action #__—______________________[description]
Action #__—______________________[description]
Action #__—______________________[description]
Completion status legend:
✓= Project Completed
O = Action ongoing toward completion
X = No progress at this time
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
E-5
Appendix E. Progress Report Template
Changes That May Impact Implementation of the Plan: (Insert brief overview of any significant changes in
the City of Phoenix that would have a profound impact on the implementation of the 2025 FMP. Specify any
changes in technical, regulatory, and financial capabilities identified during the plan’s development)
Recommendations for Changes or Enhancements: Based on the review of this report by the Floodplain
Management Plan FMP Committee, the following recommendations will be noted for future updates or
revisions to the 2025 FMP:
•
__________________________
•
__________________________
•
__________________________
•
__________________________
•
__________________________
•
__________________________
Public Review Notice: The contents of this report are considered to be public knowledge and have been
prepared for total public disclosure. Copies of the report have been provided to the City of Phoenix
governing board and to local media outlets and the report is posted on the City’s floodplain management
plan website. Any questions or comments regarding the contents of this report should be directed to:
Insert Contact Info Here
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
F-1
Appendix F. Floodplain Management Plan Credit Checklist
APPENDIX
F.
FLOODPLAIN
MANAGEMENT
PLAN
CREDIT
CHECKLIST
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
F-2
Appendix F. Floodplain Management Plan Credit Checklist
510 FLOODPLAIN MANAGEMENT PLANNING
Insert Name of Plan
512.a Floodplain Management Planning (FMP)
Credit Points: Enter the section or page number in the plan where each credited item can be found. Add notes
on AW-510-4.
CRS Step
Section/Page
Score
Total
1. Organize to prepare the plan. (15 Max)
a. Involvement of Office Responsible for Community Planning (4)
b. Planning committee of department staff (9)
c. Process formally created by the community’s governing board (2)
2. Involve the public. (120 Max)
a. Planning process conducted through a planning committee (60)
b. Public meetings held at the beginning of the planning process (15)
c. Public meeting held on draft plan (15)
d. Other public information activities to encourage input (Up to 30)
3. Coordinate with other agencies. (35 Max)
a. Review of existing studies and plans (required) (5)
b. Coordinating with communities and other agencies (Up to 30)
4. Assess the hazard. (Max 35)
a. Plan includes an assessment of the flood hazard (REQUIRED) with:
(1) A map of known flood hazards (5)
(2) A description of known flood hazard (5)
(3) A discussion of past floods (5)
b. Plan includes assessment of less frequent floods (10)
c. Plan includes assessment of areas likely to flood (5)
d. The plan describes other natural hazards (REQUIRED FOR DMA) (5)
5. Assess the problem. (Max 52)
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
F-3
Appendix F. Floodplain Management Plan Credit Checklist
a. Summary of each hazard identified in the hazard assessment and their community impact
(REQUIRED) (2)
b. Description of the impact of the hazards on: (Max 25)
(1) Life, safety, health, procedures for warning and evacuation (5)
(2) Public health including health hazards to floodwaters/mold (5)
(3) Critical facilities and infrastructure (5)
(4) The community’s economy and tax base (5)
(5) Number and type of affected buildings (5)
**c. Review of all damaged buildings/flood insurance claims (5)
** RL Category: (Insert A, B or C)
d. Areas that provide natural floodplain functions (5)
e. Development/redevelopment/Population Trends (7)
f. Impact of future flooding conditions outlined in Step 4, item c (8)
6. Set goals. (required) (2)
7. Review possible activities. (Max 35)
a. Preventive activities (5)
b. Floodplain Management Regulatory/current & future conditions (5)
c. Property protection activities (5)
d. Natural resource protection activities (5)
e. Emergency services activities (5)
f. Structural projects (5)
g. Public information activities (5)
8. Draft an action plan. (Max 60)
a. Actions must be prioritized (required)
1. Recommendations for activities from two of the six categories (10)
2. Recommendations for activities from three of the six categories (20)
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
F-4
Appendix F. Floodplain Management Plan Credit Checklist
3. Recommendations for activities from four of the six categories (30)
4. Recommendations for activities from five of the six categories (45)
b. Post-disaster mitigation policies and procedures (10)
c. Action items for mitigation of other hazards (5)
9. Adopt the plan. (2)
(Insert date of adoption)
10. Implement, evaluate and revise. (Max 26)
a. Procedures to monitor and recommend revisions (required) (2)
b. Same planning committee or successor committee that qualifies under Section 511.a.2 (a) does
the evaluation (24)
FMP=
Notes/Comments: Note if step 5c is missed, or if score is capped at 50 points, reference FEMA approval
2025 | FLOODPLAIN MANAGEMENT PLAN UPDATE – CITY OF PHOENIX, AZ
G-1
Appendix G. Floodplain Management Plan Adoption
APPENDIX G. FLOODPLAIN MANAGEMENT PLAN ADOPTION