Presentation

Large Water User
Ordinance Update
Presented by
Joe Giudice, Water Resources Director
Kathy Macdonald, Water Resources Advisor
Responsible development
through strategic water resource
management
Partnership with the business
community to protect the long-term
reliability of Mesa’s water supplies

Building on success through partnership
Mesa is building on the ordinance’s success. The
proposed updates provide commerce and
industry more flexibility to improve operations
and use water efficiently, while protecting
Mesa’s water supplies and supporting
responsible development.
1

Building on a successful ordinance
2019 2024 Ongoing refinement
One of Arizona’s first Ordinance updated to Lessons learned, benchmarking,
large water user ordinances improve effectiveness best practices and customer
feedback
No new water-cooled data centers since 2021
A successful framework for managing large industrial water demand and supporting water efficiency
and innovation
2

Goals for the next stage
Responsible Support economic development through water stewardship and
development strategic resource management.
Flexibility Give the City and customers practical options to manage demand
and adapt as conditions change.
Reliable water Protect Mesa’s water portfolio and the long-term reliability of
supplies service.
The ordinance provides a framework for Mesa and industry to work
together through the application process to assess long-term water
Industry innovation
resource sustainability and identify opportunities for water efficiency,
on-site reuse and innovation.
3

Customer examples of water innovation investments
Advanced cooling Plant-based water Cooling with Landscape and
water treatment treatment outside air fixture efficiency
Resin treatment reduces Natural treatment media Outside-air cooling when Desert-adapted plants,
water demand and helps maintain water quality conditions allow reduces efficient irrigation and water-
wastewater discharge. and reduces chemical use. water demand. saving fixtures reduce
demand.
4

Demand ceiling and customer transition
Standard Demand Ceiling (acre-feet)
Current Ordinance Proposed Ordinance
330 AF 224 AF
Residential and hospital exclusions. Add schools to the exclusions. All landscape
meters remain covered.
Transition for qualifying existing customers
Qualifying customers retain a 330 AF ceiling. A Permit and Allowance are required before exceeding 330 AF.
5



Conservation and shortage safeguards
Required conservation plan
Submit with each Permit application and renewal.
Implement approved efficiency, waste prevention
and reuse measures. Update at least every five
years during extended permit terms.
Shortage and emergency safeguards
Permits and Allowances remain subject to drought,
shortage and system constraints to protect reliable
water service for all customers.
8

A united voice for reliable water supplies
Mesa and our business community can speak
with a united voice to the Bureau of
Reclamation about the importance of reliable
water supplies to our residents, business
operations, and economic future, while
demonstrating our shared commitment to
water efficiency and responsible growth.
9

Questions?

Water Shortage
Management Plan
PROPOSED 2026 UPDATE
City Council Study Session
Joe Giudice | Water Resources Director
Nicole Petker | Water Resources Advisor
Lauren Whittaker| Deputy Director - Environmental

Water Conservation Program Overview

Commitment to Water Conservation

Mesa Leading By Example

Purpose of the Water Shortage Management Plan
A clear, flexible framework to protect water service
when water supplies or system capacity are under stress.
PREPARE EARLY PROTECT ESSENTIAL RESPOND
1 2 SERVICE 3 PROPORTIONALLY
Identify changes in supply, Prioritize drinking water, Match the reduction goal and
demand, infrastructure and sanitation, fire protection, response to the actual cause,
operations before conditions public health and long-term severity, duration and location
become critical. supply reliability. of the shortage.
It is the decision framework that helps Mesa choose the right response.
Water Shortage Management Plan Update 1

Why update the Plan now?
Lessons learned from prolonged drought and evolving water conditions point to the need for a more
flexible, portfolio-based response.
Plan to reflect Mesa today
Drought is ongoing
Flexible/Adaptable
The update aligns with Council
Mesa needs a framework that can
Prior triggers were source-specific priorities, community expectations,
handle changing regulations, supply
and stage-linked. That worked for a and a more mature water portfolio.
reductions and operational realities
simpler drought framework.
together.
Flexible – Adaptive – Effective
A more flexible, evaluative framework supports Mesa’s 100-year Assured Water Supply
while allowing the City to respond to changing conditions.
Water Shortage Management Plan Update 2

Guiding principles
Water Shortage Management Plan Update 3

Water Shortage Triggers – A Shortage is not Always Drought
↓ § ↑ !
Prolonged Reduced supply Infrastructure Regulatory High demand Combined
drought outage change conditions
Canals, plants, power, Contractual
Dry watersheds Less water available Heat and peak use Multiple pressures
chemicals availability
MAY RESULT IN A WATER SHORTAGE CONDITION
4

The proposed approach supports long-term reliability
− =
Inclusive by design: demand, renewable supply, reserve durability and future supply outlook are evaluated together.
Evaluate reserve Determine Trigger shortage
1 2 3 response
reliance reduction need
Protects Mesa’s 100-year Assured Water Supply while preserving flexibility as conditions and supplies change.
Water Shortage Management Plan Update DRAFT 3 5

Living A Desert Lifestyle
Mesa does not wait for a shortage to manage water responsibly.
Maintain
Monitor & manage Optimize water use
infrastructure
water supply at City facilities
& reduce loss
Operate efficiently & Plan for efficient Coordinate &
prevent waste growth continually improve
Water Shortage Management Plan Update 6

Water Shortage Stages
Four progressive stages. Actions reflect the shortage and local conditions.
1 2 3 4
WATER WATCH WATER ALERT WATER WARNING WATER EMERGENCY
0–10% 10–25% >25% As needed
Awareness and Voluntary, targeted and Selected measures Emergency actions to
voluntary efficiency mandatory options are mandatory protect essential services
Water Shortage Management Plan Update 7

Flexible by design: Combine the right tools for the reduction goal
Education, assistance Efficiency Restrictions, standards
& incentives improvements & enforcement
Use the combination that best fits the reduction goal,
timing, customer impacts and available resources.
Voluntary Phased / Focused Mandatory
Water Shortage Management Plan Update DRAFT 10 9

Flexible demand-management toolbox:
Examples of water-saving actions
AMI leak alerts 4.0% Large landscape budgets 1.2%
Outdoor watering days/frequency 4.3% High-use conservation plans 1.2%
Winter overseeding restrictions 4.3% Cooling-tower efficiency 1.1%
Utility water-loss reduction 2.0% Water-waste enforcement 1.0%
High-use engagement/reviews 1.2% Overnight outdoor watering 1.1%
Education / assistance Efficiency improvements Restrictions / standards
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Water Shortage Management Plan Update

Illustrative example: a 10% to 25% reduction goal
Different actions can contribute to the same community goal.
Phased / Focused
• Large landscape reviews
• High-use conservation plans
• Cooling-tower optimization
• Water-waste warnings
Voluntary / Supportive Mandatory
• Stage-specific 10%-25%
• Water-waste enforcement
communications
• AMI leak guidance Community • Outdoor watering schedules
• Overnight outdoor watering
• High-use customer outreach reduction goal • Winter overseeding limits
• Water Use It Wisely resources
Water Shortage Management Plan Update 11

Public communication and input
A clear public message is part of every shortage stage.
The stage The scope The objective The actions The progress
Which stage applies Where it applies and The water-use What is voluntary or Results and when
and why. how long it may last. reduction target. required, and measures may
effective dates. change.
Public input helps confirm that the approach is understandable, practical and aligned
with community expectations.
Water Shortage Management Plan Update 12

Next steps
Complete the framework, confirm 2027 conditions, then determine the appropriate shortage stage.
Return to Council
Ordinance adoption + updated Plan Early
2027
Continue monitoring
Pending legal developments
Shortage Stage
Recommendation
Finalize 2027 water order
Current estimated reductions + supply
conditions
27

A comprehensive, adaptable and measurable approach to water resilience.
Questions??
14