03. 04.CPA250001 Z250001 Harquahala Flats PZ Staff Report
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CPA250001 and Z250001
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Report to the Planning and Zoning Commission
Prepared by the Maricopa County Planning and Development Department
Case:
CPA250001 & Z250001 – Harquahala Flats Energy Storage Project
Hearing Date:
June 26, 2025
Supervisor District:
4
Applicant:
Keith Nichter, Kimley-Horn
Owners:
Christopher, Katherine, Nicholas, Rebecca, Ronald, Theresa, and Timothy
Peters
Requests:
1.
General Comprehensive Plan Amendment (CPA) to change the land use
designation in the Tonopah Arlington Area Plan from ‘Rural Densities’ and
‘Large Lot Residential’ to ‘Utilities’
2.
Zone Change with Overlay from Rural-43 to IND-2 IUPD for a photovoltaic
solar energy generation and a battery energy storage (BESS) system
Site Location:
Generally located on both sides of I-10 at the 443rd Ave. alignment in the
Harquahala Valley area
Site Size:
Approximately 321 acres
Density:
N/A
County Island:
No
County Plan:
Tonopah Arlington Area Plan – Rural Densities and Large Lot Residential
Municipal Plan:
N/A
Municipal Comments:
None received to date
Support/Opposition:
None known
Recommendations:
1.
CPA250001 - Approve
2.
Z250001 – Approve with conditions
CPA250001 and Z250001
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Project Summary:
1.
The applicant is proposing a General CPA to the Tonopah Arlington Area Plan to change the land
use designations from Rural Densities and Large Lot Residential to Utilities with a zone change
with overlay from Rural-43 to IND-2 IUPD to allow for a photovoltaic solar energy generation and
a battery energy storage (BESS) system with a 500kv step-up substation. The site consists of
321-acre parcel straddling both sides of I-10 at 443rd Ave. The initial development would consist
of a BESS facility south of I-10’s eastbound ROW with later development of the land to the north
past I-10 being dedicated to photovoltaic solar energy panels. Final kilowattage production of the
solar energy generation facility is yet to be determined as of this report as it would be part of a
later phase of development. The facility would tie from existing powerlines to the APS Delaney
substation to the southwest.
2.
Much of this area has been developed for solar uses in the past several years as solar power has
become a prominent part of Arizona’s energy grid. The facility would continuously operate and
employ up to 400 employees during the phases of construction with 10 full-time maintenance
employees upon buildout. Site screening would be limited to chain-link fencing with additional
barbed wiring given the mostly vacant rural surroundings, with only a sparsely populated
residential community to the site’s southeast at 443rd Ave. The nearest home in this area is
approximately a quarter mile from the location of the BESS batteries. Several changes are
requested as part of the IUPD overlay to accommodate the proposed BESS facility, as well as to
relieve several regulations. The table below shows all requested changes to the underlying zoning
district with modification to standards shown bolded.
REGULATION
IND-2 Base Zoning District
Standard (IND-2 IUPD)
PROPOSED ZONING DISTRICT
REGULATIONS (IND-2 IUPD)
Minimum Front Yard
10'
100’ for BESS, 10’ for PV panels
Minimum Side Yard
3’
100’ for BESS, 3’ for PV panels
Minimum Street-side Yard
10’
100’ for BESS, 10’ for PV panels
Minimum Rear Yard
25'
100’ for BESS, 25 for PV panels
Parking Spaces
See parking regulations
None Required
Screening
6' solid wall
Chain-link fencing and gates shall
be allowed on the perimeter of the
project. Barbed wire attached to
fencing under 8’ will be allowed
within the property boundaries
Paving Requirements
Article 1102.7.1
Parking/paving material allowed to
be stabilized decomposed granite
with an approved dust control plan
by Maricopa County Air Quality
Control.
Loading and Unloading
Article 1103.2
No loading or unloading space
required
Landscaping
Article 901.4.1
No landscape strip required
Sight Visibility Triangles
Article 1111.5.5.3.
No SVT’s at project site, entry/exit
points, section line, and mid-
section line intersecting
alignments
Uses outside of an enclosed
building
Article 902.9.1
All utility uses permitted outdoors
Max Electric Transmission Line
Height
120’
150’
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3.
The narrative asserts that the proposed development meets the Comprehensive Plan
Amendment criteria in the following manner:
Whether the amendment constitutes an overall improvement to the Comprehensive Plan and is
not solely for the good or benefit of a particular landowner or owners at a particular point in time.
The applicant states that the Harquahala Flats Energy Storage Project aligns with the Vision 2030
Maricopa County Comprehensive Plan by supporting renewable energy development in response
to changing market demands and infrastructure needs. They say the project is expected to
generate hundreds of construction jobs and long-term maintenance roles, contributing to the
local economy through tax revenue and use of regional contractors. They say its proximity to
existing utility infrastructure minimizes environmental impact and improves grid efficiency. By
advancing renewable energy and battery storage capacity, the project supports Arizona's
Renewable Portfolio Standard goals and Arizona Public Service Co.'s clean energy targets,
fostering economic development, innovation, and energy independence within Maricopa County
and beyond.
Whether the amendment will adversely impact all or a portion of the planning area by:
Altering acceptable land use patterns to the detriment of the plan.
The applicant states the proposed General Comprehensive Plan Amendment (CPA) will not
negatively affect acceptable land use patterns in the area and is consistent with previously
approved utility uses and zoning changes. The applicant argues that existing infrastructure
investments make the site well-suited for future power generation and storage. The proposal
aligns with the Plan’s Renewable Energy Strategy, which encourages the attraction of alternative
energy development to Maricopa County. The applicant states that increasing the county’s
support for solar power generation and storage will help lower long-term energy costs by boosting
local supply and improving efficiency. This, in turn, supports integration of clean energy into
sectors like housing, manufacturing, and transportation. The requested land use change from
Rural Densities (0–1) to Utilities is said to conform with the Plan’s renewable energy policies and
energy-related goals.
Requiring public expenditures for larger and more expensive infrastructure.
According to the application all associated infrastructure, access, and transmission costs will be
borne by the developer.
Requiring public improvements to roads, sewer, or water systems that are needed to
support the planned land uses.
The applicant expects limited impacts to roads, sewer, and water systems due to the nature of
the project’s use.
Adversely impacting planned uses because of increased traffic.
According to the application the use will have limited impact on the transportation system beyond
the construction phase of the project.
Affecting the livability of the area or health or safety of present and future residents.
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The applicant contends the facility will not result in undue or unmitigated social, visual, traffic, air
quality, water quality, or other impacts which may have a disproportionate affecting the livability
of the area.
Adversely impacting the natural environment or scenic quality of the area in contradiction
to the plan.
The area is sparsely populated and there are other similar facilities nearby. The applicant has
indicated that they will work with Arizona Game and Fish to protect local fauna from impacts and
that the facility will not adversely impact the scenic quality of the area. The applicant has also
pledged to maintain compliance with applicable Maricopa County Air Quality Department
permitting and operational standards, including conformance with U.S. Environmental Protection
Agency (EPA), and Arizona Department of Environmental Quality.
Whether the amendment is consistent with overall intent of the comprehensive plan:
The applicant argues that the application supports Maricopa County’s mission statement and
strategic priorities by supporting the future need in renewable energy, which has been identified
as a strategic priority.
The extent to which the amendment is consistent with the specific goals and policies contained
within the plan:
According to the applicant, the proposal meets the following plan elements of the Vision 2030
Plan and Tonopah/Arlington Area Plan:
Land Use Element: Goal 3, Policy 7, Policy 20, Policy 22
Transportation Element: Goal 1, Goal 2, Goal 3, Policy 11, Policy 12
Environmental Element: Goal 1, Policy 2, Policy 3, Policy 4, Policy 5
Economic Growth Element: Goal 1, Policy 5, Policy 10
Growth Area: Goal 1, Policy 1
Water Resources Element: Goal 4, Policy 2, Policy 4, Policy 5, Policy 7
Energy Element: Goal 1, Goal 2, Policy 6
Cost of Development Element: Goal 1, Goal 2, Policy 1
Open Space Element: Goal 1
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Aerial photo of subject site and surrounding environs
Eagle view of subject site looking east into subject parcel (aerial image dated 10/1/21)
CPA250001 and Z250001
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Portion of site plan with north oriented to the left. BESS facility proposed south of Interstate 10 with PVs north of Interstate 10.
Existing On-Site and Adjacent Zoning / Land Use:
4.
On-site:
Rural-43 / Vacant
North:
Rural-43 / Vacant
South:
Rural-43 / Vacant
East:
Rural-43 / Vacant
West:
Rural-43 / Vacant
Zoning District map – the IND-2 zones are all similar solar facilities
CPA250001 and Z250001
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Utilities and Services:
5.
Water:
Well (portion of site south of I-10)
Wastewater:
On-site septic (portion of site south of I-10)
Fire:
AZFMA
Police:
MCSO
Right-of-Way:
6.
The following table includes existing and proposed half-width right-of-way and the future
classification based upon the Maricopa County Department of Transportation (MCDOT) Major
Streets and Routes Plan.
Street Name
Half-width Existing R/W
Half-width Proposed R/W
Future Classification
443rd Ave
65’
130’
Local
Adopted Plan:
7.
Tonopah/Arlington Area Plan (adopted September 6, 2000):
Rural Densities: The Rural category denotes areas where single family residential development is
desirable but urban services (sewer, water, law enforcement, fire protection, schools, parks, etc.)
are limited. Suitability is determined on the basis of location, access, existing land use patterns,
and natural or man-made constraints. Densities greater than 1.0 du/acre may be permitted in a
new development, but only if areas of lower densities offset the increase such that an average of
no more than 1.0 du/acre is maintained. Uses in this category include agricultural and single
family residential.
Large Lot Residential: The Large Lot Residential category denotes areas where single family
residential development is desirable and urban services (sewer, water, law enforcement, fire
protection, schools, parks, etc.) may only be partially available or be required as an improvement
district. Suitability is determined on the basis of location, access, existing land use patterns and
natural or man-made constraints. In a development, densities greater than 2.0 du/acre may be
permitted, but only if areas of lower densities offset the increase such that an average of no more
than 2.0 du/acre is maintained. A community sewer and water system will be required for
developments above 1.0 du/acre and may be required for those below 1.0 du/acre depending on
the underlying conditions.
Public Participation Summary:
8.
The applicant has complied with the Maricopa County public participation process with the
required posting of the property and the notification to the adjacent property owners within 300’
of the subject site. The applicant did not receive a response from their public outreach efforts.
Staff has not received any notice of opposition or support to the request.
Outstanding Concerns from Reviewing Agencies:
9.
N/A.
Staff Analysis:
CPA250001 and Z250001
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10.
Maricopa County recognizes the potential environmental and economic benefits that solar
technology can provide. This facility will use photovoltaic technology that generates energy from
sun absorption. Photovoltaic technology differs from other models of solar electric generation
that require vast amounts of water to cool the units. In contrast, very little water is utilized for
photovoltaic technology. As a result, this development would not pose a threat to the groundwater
supply.
11.
Staff believes the proposed solar facility is well suited to this rural area, which requires large
amounts of relatively flat land on both sides of I-10. Staff agrees with the applicant that the
subject site is suitable due to proximity to electrical transmission lines, nearby stations and
substation, and because the surrounding area is vastly undeveloped. Staff agrees with the
applicant that the project will not detrimentally affect the visual quality of the area. Finally, the
associated BESS facilities are compatible with rural areas where there is less danger from
potential battery fires than there would be from other, more urban areas.
Recommendations:
12.
Staff recommends the Commission adopt a motion recommend that the Board of Supervisors
approve CPA250001.
13.
Staff recommends the Commission adopt a motion recommending that the Board of Supervisors
approve Z250001 subject to the following conditions ‘a’ – ‘h’:
a.
Development of the site shall be in substantial conformance with the Site Plan entitled
“Harquahala Flats Energy Storage“, consisting of 1 full-size sheets, dated April 2, 2025
except as modified by the following conditions. Staff may determine slight refinements to
remain in substantial conformance with the approved site plan. Minor and major
amendments to the site plan will be determined in accordance with Chapter 3 of the
Maricopa County Zoning Ordinance.
b.
Development of the site shall be in substantial conformance with the Narrative Report
entitled Harquala Flats Energy Storage”, consisting of 23 pages and 12 pages respectively,
both dated March 4, 2025, except as modified by the following conditions.
c.
The following Planning Engineering conditions shall apply:
1.
Without the submittal of a precise plan of development, no development approval
is inferred by this review, including, but not limited to number of proposed building
lots/units, drainage design, access and roadway alignments. These items will be
addressed as development plans progress and are submitted to the County for
further review and/or entitlement.
2.
Development in regulated floodplains must comply with the Floodplain
Regulations for Maricopa County.
3.
A traffic impact study must be submitted with future entitlement application(s).
4.
Private utilities that will occupy County R/W require a license in addition to any
construction related permits. Contact MCDOTsolarlicense@maricopa.gov. See
https://www.maricopa.gov/DocumentCenter/View/74250/MCDOT-SolarLicense-
Application for more information.
CPA250001 and Z250001
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5.
Engineering review of re-zone cases is conceptual in nature. All development and
engineering design shall be in conformance with Section 1205 of the Maricopa
County Zoning Ordinance; Drainage Policies and Standards; Floodplain
Regulations for Maricopa County; MCDOT Roadway Design Manual; and current
engineering policies, standards and best practices at the time of application for
construction.
d.
The following IND-2 IUPD standards shall apply:
1.
Max Electrical Transmission Line Height: 150’
2.
Front Yard: 100’ for BESS, 10’ for PV panels
3.
Side Yard: 100’ for BESS, 3’ for PV panels
4.
Street-side Yard: 100’ for BESS, 10’ for PV panels
5.
Rear Yard: 100’ for BESS, 25’ for PV panels
6.
Screening: Chain-link fencing and gates shall be allowed on the perimeter of the
project. Barbed wire attached to fencing under 8’ will be allowed within the property
boundaries
7.
Paving Requirements: Parking/paving material allowed to be stabilized
decomposed granite with an approved dust control plan by Maricopa County Air
Quality Control.
8.
Loading and Unloading: No loading or unloading space required.
9.
Landscaping: No landscape strip required
10.
Sight Visibility Triangles: No SVT’s at project site, entry/exit points, section line,
and mid-section line intersecting alignments.
11.
Uses outside of an enclosed building: All utility uses permitted outdoors.
e.
Noncompliance with any of the conditions assigned to the approval of this Zone Change
by the Maricopa County Board of Supervisors may be grounds for revocation in
accordance with the requirements and procedures as set forth in the Maricopa County
Zoning Ordinance.
f.
Noncompliance with any Maricopa County regulation shall be grounds for initiating a
revocation of this zone change as set forth in the Maricopa County Zoning Ordinance.
g.
The property owner/s and their successors waive claim for diminution in value if the
County takes action to rescind approval due to noncompliance with conditions.
h.
The granting of this change in use of the property has been at the request of the applicant,
with the consent of the landowner. The granting of this approval allows the property to
enjoy uses in excess of those permitted by the zoning existing on the date of application,
subject to conditions. In the event of the failure to comply with any condition, the property
may be considered for reversion to the zoning that existed on the date of application in
accordance with Maricopa County Zoning Ordinance requirements. It is, therefore,
stipulated and agreed that reversion of the zoning due to the failure to comply with any
conditions does not reduce any rights that existed on the date of application to use, divide,
sell or possess the property and that there would be no diminution in value of the property
from the value it held on the date of application due to such reversion of the zoning. This
zone change enhances the value of the property above its value as of the date the zone
change is granted and reverting to the prior zoning results in the same value of the
property as if the zone change had never been granted.
Presented by:
Joel Landis, Planner
Reviewed by:
Rachel Applegate, Planning Supervisor
CPA250001 and Z250001
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Attachments:
Case Maps (2 pages)
CPA Narrative Report (23 pages)
Zoning Narrative Report (12 Pages)
Site Plan (1 page)
MC Engineering Comments (1 pages)
MCDOT TIS Approval (10 pages)
/
Maricopa County Planning & Development - Phoenix, AZ
4
Gross Acres: 320 approx.
Generated May 28, 2025 1:00 PM
CPA250001
Application Name:
Legal Description
HARQUAHALA FLATS ENERGY STORAGE PROJECT
Applicant
Case Address
2N 7W 18
Keith Nichter
Applicant Phone/Email
Parcel Primary:506-31-015
(602) 313-7206
keith.nichter@kimley-horn.com
Map scale 1:13,101
Supervisor District No.
Proposed General Comprehensive Plan Amendment (CPA) to change the land use designation from Rural
Densities (0-1) to Utilities.
/
Maricopa County Planning & Development - Phoenix, AZ
4
Gross Acres: 320 approx.
Generated May 28, 2025 1:06 PM
Z250001
Application Name:
Legal Description
HARQUAHALA FLATS ENERGY STORAGE PROJECT
Applicant
Case Address
2N 7W 18
Keith Nichter
5500 N 443RD AVE
Applicant Phone/Email
Parcel Primary:506-31-015
(602) 313-7206
keith.nichter@kimley-horn.com
TONOPAH, AZ 85354
Map scale 1:13,101
Supervisor District No.
Proposed Zone Change with Overlay to change the existing zoning from RU-43 (Rural) to IND-2 IUPD
district (Light Industrial)
kimley-horn.com
1001 West Southern Avenue Suite 131, Mesa, AZ 85210
480 207 2666
Exhibit A - Vicinity Map
General Location: The proposed site is located roughly 4 miles west of Tonopah/15 miles west of
Buckeye on a vacant +/-321-acre privately owned parcel, which straddles Interstate 10 in the northeast
quarter of section 18, township 2 north, range 7 west in unincorporated Maricopa County, Arizona.
HARQUAHALA FLATS ENERGY
STORAGE PROJECT
CASE #: CPA250001 & Z250001
REQUEST: General Comprehensive Plan Amendment from
Rural Densities (0-1) to Utilities on Approximately 321.10 Acres
NARRATIVE REPORT FOR
01-10-2025, Revised 03-04-2025
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kimley-horn.com
1001 West Southern Avenue Suite 131, Mesa, AZ 85210
480 207 2666
TABLE OF CONTENTS
A. EXECUTIVE SUMMARY ................................................................................................................ 3
I.
ON-SITE AND REGIONAL LOCATION .................................................................................... 3
II.
CPA SIZE AND DESCRIPTION OF LAND USE TYPES BY ACREAGES ............................... 3
III.
ROADS/TRANSPORTATION SYSTEMS SERVING THE PROPOSED PROJECT ................ 4
IV.
SUITABILITY WITH SURROUNDING LAND USES ................................................................. 5
TABLE 1 - EXISTING SURROUNDING SOLAR (UTILITY) LAND USE APPROVALS ..................... 6
B. WHETHER THE AMENDMENT CONSTITUTES AN OVERALL IMPROVEMENT TO THE
COMPREHENSIVE PLAN AND IS NOT SOLELY FOR THE GOOD OR BENEFIT OF A
PARTICULAR LANDOWNER OR OWNERS AT A PARTICULAR POINT IN TIME. .......................... 6
C. THE AMENDMENT WILL NOT ADVERSELY IMPACT ALL OR A PORTION OF THE
PLANNING AREA BY: *EACH CRITERION IS ADDRESSED SEPARATELY WITH THE CRITERIA
LISTED AND GENERAL RESPONSES TO THE CRITERIA CITED AS SUBHEADINGS IN THE
PROCEEDING SUBSECTIONS BELOW: ............................................................................................. 8
I.
ALTERING ACCEPTABLE LAND USE PATTERNS TO THE DETRIMENT OF THE PLAN. .. 8
II.
REQUIRING PUBLIC EXPENDITURES FOR LARGER AND MORE EXPENSIVE
INFRASTRUCTURE. .......................................................................................................................... 8
III.
REQUIRING PUBLIC IMPROVEMENTS TO ROADS, SEWER, OR WATER SYSTEMS
THAT ARE NEEDED TO SUPPORT THE PLANNED LAND USES. ................................................. 9
IV.
ADVERSELY IMPACTING PLANNED USES BECAUSE OF INCREASED TRAFFIC. ........... 9
V.
AFFECTING THE LIVABILITY OF THE AREA OR HEALTH OR SAFETY OF PRESENT AND
FUTURE RESIDENTS. ..................................................................................................................... 10
VI.
ADVERSELY IMPACTING THE NATURAL ENVIRONMENT OR SCENIC QUALITY OF THE
AREA IN CONTRADICTION TO THE PLAN. ................................................................................... 10
D. WHETHER THE AMENDMENT IS CONSISTENT WITH OVERALL INTENT OF THE
COMPREHENSIVE PLAN: .................................................................................................................. 12
E. THE EXTENT TO WHICH THE AMENDMENT IS CONSISTENT WITH THE SPECIFIC GOALS
AND POLICIES CONTAINED WITHIN THE PLAN. ............................................................................ 13
F. COMPREHENSIVE PLAN AMENDMENT MAP EXHIBIT ........................................................... 21
G. COMPREHENSIVE PLAN AMENDMENT LEGAL DESCRIPTIONS EXHIBITS ........................ 22
APPENDIX - A ‘SITE PARCELS’ ........................................................................................................ 23
PROJECT TEAM
PLANNING/ENTITLEMENTS/ APPLICANT/
DEVELOPER
ENGINEERING
REPRESENTATION
HARQUAHALA FLATS ENERGY
KIMLEY-HORN
PEW & LAKE PLC
STORAGE, LLC
CONTACT: KEITH NICHTER
CONTACT: RALPH PEW
CONTACT: JAMES JACKSON
(PLANNING), SHANE
480.461.4670
JAMES.JACKSON4@NEXTERAENERGY.COM JOHANNSEN (ENGINEER)
RALPH.PEW@PEWANDLAKE.COM
602.313.7206
KEITH.NICHTER@KIMLEY-HORN.COM
SHANE.JOHANNSEN@KIMLEY-HORN.COM
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kimley-horn.com
1001 West Southern Avenue Suite 131, Mesa, AZ 85210
480 207 2666
A. EXECUTIVE SUMMARY
“Pew & Lake, PLC (the “Applicant”), on behalf of Harquahala Flats Energy Storage, LLC, a wholly-
owned, indirect subsidiary of NextEra Energy Resources (the “Developer”), with the permission of the
Property Owners identified in a separate appendix, is requesting a General Comprehensive Plan
Amendment (CPA) of the Vision 2030 Comprehensive Plan to change the land use designation for the
±321-acre Harquahala Flats Energy Storage Project (“Project”) from Rural Densities (0-1) to Utilities.
The General CPA request will be accompanied by a concurrent zone change request to rezone the
underlying parcels from RU-43 to the IND-2 IUPD Zone. This General CPA will affect the land use
designation of one (1) parcel (506-31-015) allowing for future photovoltaic solar energy generation and
a battery energy storage (BESS) system, step-up substation and associated infrastructure.
The BESS facility, which stores energy for later use, will improve reliability, availability, and efficiency
of the power supply. Additionally, the 500 kV step-up substation will accommodate the future gen-tie
connection that will link the site to the grid via overhead electrical structures, completing connection to
the existing APS Delaney substation located +/-2 miles to the southwest. The site will also include one
or more small buildings to house telecommunication equipment and allow for future BESS and/or solar
generation on the northern portion of the property.
Off-site supporting improvements, infrastructure, and/or uses include a gen-tie route corridor that
extends through Arizona State Land Department (ASLD) to the APS Delaney substation.
The proposed ±321-acre General CPA request, will not adversely impact the planning area and is
consistent with other nearby Utility land use designations within and around the Harquahala Valley
area. Approval of the proposed General CPA, concurrent rezone and associated development plans
for the proposed project will not generate undue nor unmitigated impacts to the following areas of
consideration identified in the Comprehensive Plan, which include, but are not specifically limited to:
land use; public transportation system improvements; drainage and/or stormwater management;
environmental considerations (air & water quality, potable water & wastewater treatment), areas of
geologic concern, hazard, and/or significance; plant and wildlife habitat/migration environs and/or
patterns; aviation and military installation operations and flight paths/patterns; economic growth; growth
areas; open space, water resources; energy; and/or the cost of development.
I.
ON-SITE AND REGIONAL LOCATION
The proposed Project is rectangular in shape and straddles Interstate 10, located north of
Saddle Mountain, southeast of the Big Horn Mountains, at the northwest corner of the
Camelback Road and 443rd Avenue alignments on Section 18 Township 2 North, Range 7
West, 4 miles west of Tonopah Arizona in unincorporated Maricopa County.
II.
CPA SIZE AND DESCRIPTION OF LAND USE TYPES BY
ACREAGES
The General CPA is inclusive of one (1) parcel which is held under one (1) owner. The
cumulative area of the property included in the General CPA request is ±321-acres. The subject
property is generally vacant with the exception the Interstate 10 corridor which bisects the
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kimley-horn.com
1001 West Southern Avenue Suite 131, Mesa, AZ 85210
480 207 2666
southern quarter of the site with the majority of the parcel located north of I10. The parcel
considered under this General CPA is listed in Appendix A.
The existing land use designation for the site is Rural Densities (0-1) which is intended to
conserve and protect open land uses, foster orderly growth in rural and agricultural areas, to
prevent urban and agricultural land use conflicts, and to encourage sustainable development.
The current RU-43 zoning district is intended to have residential densities of one (1) dwelling
unit per acre (du/ac). Principal permitted uses in the Rural zoning districts include both farming
and non-farming related residential uses, farms, and recreational and institutional uses. The
proposed Utilities land use and corresponding IND-2 IUPD (Light Industrial) zoning will be
consistent with surrounding approvals necessary to develop the proposed BESS facility and
potential future solar generation.
III.
ROADS/TRANSPORTATION SYSTEMS SERVING THE
PROPOSED PROJECT
The roadway network serving the proposed Project from the I-10 corridor includes the I-
10/411th Ave interchange (exit 94) that connects to Indian School Road and access to the site
via 443rd Ave in accordance with access management policies and permitting requirements of
Maricopa County.
For the direct access Harquahala Flats Energy Storage Project will preserve necessary
identified street right-of-way and, per Maricopa County Zoning Ordinance Section 1105, will
Harquahala Flats Energy Storage Project – Harquahala Flats Energy Storage Project –
Existing Zoning RU-43
Proposed Zoning IND-2 IUPD
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1001 West Southern Avenue Suite 131, Mesa, AZ 85210
480 207 2666
provide the necessary setbacks starting from the future half street rights-of-way. Offsite
improvements and any additional right-of-way needed will be determined by MCDOT Traffic
Design and MCDOT Permits based on the submittal of a traffic statement. Final dedication,
preservation, alignments, terminations, and vacations of unneeded ROW will be determined in
negotiation with MCDOT.
There would be no significant increase in traffic during the operational life of the Project that
would require road improvements. There would be a relatively minor increase in the level of
traffic during the phased construction. This increased traffic is expected to be minor during
single peak morning and evening hours, primarily for the delivery of equipment and supplies
and the commuting of the construction workforce. The TIS will be completed as part of the zone
change process associated with the Project. The Developer has agreed to financial
responsibility for repair of existing roads used during construction, including bonding for such
work, so that there is not public expenditure for transportation infrastructure associated with
the Project.
IV.
SUITABILITY WITH SURROUNDING LAND USES
The surrounding area is characterized by active and passive agricultural land uses, natural
gas-powered electric generation facilities, solar powered electric generation facilities, and
native desert lands. The surrounding land uses include publicly owned and managed Local,
State, and Federal Lands. These include lands controlled by the Arizona State Land Trust, and
Bureau of Land Management. Other surrounding land uses include vacant lands, the Interstate
10 transportation corridor and limited sparse distribution of privately owned parcels used for
residential purposes to the southeast. Additionally, Luke Air Force Base (LAFB) is known to
have military training routes out in this area. Under the Department of Defense (DOD)
Clearinghouse process, energy projects greater than 199’ above ground level are required to
go through a Formal Review. The routes in this area already fly over several existing 500kV
lines and fly nearby several other solar and BESS projects. The proposed gen-tie pole heights
will vary slightly, but no pole height is expected to exceed 199’. Although, the Project team will
be proactive in addressing any potential concerns and will submit under the Informal Review
DOD Clearinghouse process during the zoning process.
Property owners and residents will be notified of the project and efforts will be made to identify
concerns over visual impacts and incorporate effective mitigation and screening of the site
against any residential boundaries.
Considerations for buffering and screening of the Project and mitigation of visual impacts during
construction and operational activities. Screening and mitigation of visual impacts will be
addressed in greater detail at the rezone and plan of development submittals.
The exterior of the BESS site will be enclosed by perimeter security fencing located on the
portion of the parcel south of I-10. No fencing will impede or otherwise enclose existing roads
within the project boundaries.
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The Project and the proposed Utilities land use is compatible with other similar approved and
implemented solar and BESS projects within the general area. Associated facilities within this
area include approved other CPA’s for Utility (solar) land uses, BESS, PV solar generation
facilities, utility corridors, transmission lines and a utility substation. Other nearby projects are
as follows:
TABLE 1 - EXISTING SURROUNDING SOLAR (UTILITY) LAND USE APPROVALS
Project
Location (Township/Range)
Maricopa Solar and Storage Project
T1N R8W; T1N R9W; T2N R8W; T2N R9W
Harquahala Sun
T1N R9W
Harquahala Sun II and III
T1N R9W
Saddle Mountain Solar
T1N R9W
Eagletail Solar Farm
T1S R9W
Almeria Solar
T2N R8W
Sun Valley North
T2N R8W
Sun Valley South
T2N R8W
Areva Solar AZ II
T2N R7W
Papago Solar
T2N R8W
Tonopah Photovoltaic
T2N R8W
B. WHETHER THE AMENDMENT CONSTITUTES AN OVERALL
IMPROVEMENT TO THE COMPREHENSIVE PLAN AND IS NOT
SOLELY FOR THE GOOD OR BENEFIT OF A PARTICULAR
LANDOWNER OR OWNERS AT A PARTICULAR POINT IN TIME.
Per the Vision 2030 Maricopa County Comprehensive Plan (2016), Comprehensive Plan Amendments
should improve the county’s overall condition and not undermine the plan’s core principles. The Plan
recognizes the need to redesignate land uses in response to changing market conditions and to
address the increasing demands of growth to the public infrastructure needs, specifically energy
generation and consumption demands within the local economy.
As stated, and reinforced in the Plan, the supply of energy is essential to the region’s transportation
and manufacturing sectors. Energy resources significantly impact economic development by
contributing to the region’s overall attractivity on basic and corresponding non-basic employment,
primary and secondary employment sectors and markets, and research and development within
existing and emerging markets and industries. Additionally, energy availability and even surplus
opportunities function as an incubator for innovations within all segments of the local, regional, and
state economy.
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The Project is anticipated to generate approximately 250-400 jobs in the construction, contracting,
administrative, and project management fields during the construction phase. Routine maintenance
activities will be performed by up to 10 full time employees based out of offsite regional facilities for
equipment repair and replacement as needed per phase. In addition to providing in state construction
jobs and long-term technical careers, local projects like The Harquahala Flats Energy Storage Project
will help contribute to the regional economy by providing tax revenue and by using local engineering
and development contractors in Maricopa County.
The Harquahala Flats Energy Storage Project supports the county and greater region within the state
by providing additional renewable energy resources and battery storage for local energy reliability and
resiliency. The location and surrounding utility land uses minimize impacts to neighbors and lessen the
impact to the environment based on proximity to the APS Delaney Substation by minimizing very long
electrical interconnects. The electricity stored through these facilities would be distributed to the
regional electrical grid, supplying the county and state while directly benefitting Arizona corporations
seeking competitively priced renewable energy and looking to add new clean energy resources to
power the record number of people and companies moving to the state. Specifically, consistent with
their 2020 Clean Energy Commitment, Arizona Public Service Co. (APS) is looking to add additional
clean energy resources to its diverse power supply and has issued a request for proposals (RFP) to
supply renewable energy, which the Harquahala Flats Energy Storage Project supports.
This Project is intended to promote and incentivize the production and delivery of renewable energy
resources that meet and otherwise support consumption needs of existing and emerging markets which
benefit the regional and state economies and tax bases. The availability of sustainable, renewable, and
economically efficient energy and the resulting cost savings, both immediate and over time, creates
opportunity for reinvestment of public and private capital back into the local and regional economy.
The proposed Harquahala Flats Energy Storage Project is in direct support of this stated goal, the
implementation of which is evidenced by the current approved CPA and rezoning of property within the
current Project vicinity for solar and BESS projects. The need for this Project is established by growing
demand for renewable energy as evidenced by the APS RFP and Arizona’s Renewable Portfolio
Standard (RPS). RPS are policies designed to increase the use of renewable energy sources for
electricity generation. These policies require or encourage electricity suppliers to provide their
customers with a stated minimum share of electricity from eligible renewable resources. Most states,
including Arizona, have enacted their own RPS programs to diversify their energy resources, promote
domestic energy production and encourage economic development. Arizona has set their standards
for investor-owned utilities at 45% by 2030 and 100% by 2050.
Harquahala Flats Energy Storage Project, along with the many similar energy production and storage
project approvals in the area, will strengthen the overall energy production output within Maricopa
County. The increased local production and storage over time will create energy surplus within the
market resulting in a reduction of cost and consumption by additional sectors of the local and regional
economy. Project approval facilitates a larger regional share of renewable energy generation activities
within the national production mix thereby promoting energy independence throughout related national
industries and markets.
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C. THE AMENDMENT WILL NOT ADVERSELY IMPACT ALL OR A
PORTION OF THE PLANNING AREA BY: *EACH CRITERION IS
ADDRESSED SEPARATELY WITH THE CRITERIA LISTED AND
GENERAL
RESPONSES
TO
THE
CRITERIA
CITED
AS
SUBHEADINGS IN THE PROCEEDING SUBSECTIONS BELOW:
I.
ALTERING ACCEPTABLE LAND USE PATTERNS TO THE
DETRIMENT OF THE PLAN.
The proposed General CPA will not alter the acceptable land use patterns in the planning area
in an adverse manner to the detriment of the plan. The proposed change in land use is
consistent with existing approved utility land use patterns and subsequent zone change
requests. Previous land use approvals should not be construed to imply future precedents, nor
obligate future Board of Supervisor decisions. However, the infrastructure investment and
development within this portion of the planning area make the Project site a more suitable and
logical location for future development of power generation and storage. The single Renewable
Energy Strategy in the Plan promotes/encourages the “[attraction] of solar and other alternative
energy research and development to Maricopa County.” Approval of the General CPA is
consistent with this strategy and the utility pattern that has been established in the Project area
by recent BOS approvals in favor of large-scale solar powered generation and storage facilities
within this remote area.
Increasing the county’s investment (in terms of land use planning) in local solar powered
generation and storage facilities has a long-term tangible impact of lowering costs of energy
production, delivery, and consumption. This goal is achieved in part by increasing local/regional
energy production/generation. The increased supply has a proportionate impact on the
accessibility of the resource and encourages integration of applied uses and transitions away
from reliance on outdated and inefficient modes of energy generation and transmission creating
efficiencies in these areas. Increased supply and efficiencies will promote increased integration
into the market for various sectors of the economy (housing, manufacturing, transportation,
etc.).
The General CPA to change the land use from Rural Densities (0-1) to Utilities to accommodate
the proposed uses is in substantial conformance with renewable energy policies identified in
the Plan, addressed in the Energy Goal and Policy Considerations in Section D of this report.
II.
REQUIRING PUBLIC EXPENDITURES FOR LARGER AND
MORE EXPENSIVE INFRASTRUCTURE.
Any and all expenditures for larger and more expensive infrastructure that are required as a
result of the development shall be borne by the developer. Improvements for adjacent access
roads will be borne solely at the expense of the developer proportionate to the impacts placed
on the transportation network. Any public or private electric transmission infrastructure
improvement costs needed in support of the Project will be borne solely by the developer.
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III.
REQUIRING PUBLIC IMPROVEMENTS TO ROADS,
SEWER, OR WATER SYSTEMS THAT ARE NEEDED TO
SUPPORT THE PLANNED LAND USES.
The amendment will not adversely impact the planning area by requiring public improvements
to roads, sewer, or water system needed to support the planned land uses. The provision of
these services will be the responsibility of the developer in a manner that does not detract or
negatively impact the availability, delivery, and/or use of existing services within the planning
area. All costs for public improvements or services necessary to support the planned
development will be borne solely by the developer.
Options for construction and operational water needs is currently under examination by the
Developer, and none of these options would require improvements to public water systems.
Each phase of the Project is anticipated to require approximately 80-100 acre-feet of water
over the construction period. This water will be sourced from potential on-site wells or hauled
in from outside sources. During the O&M phase, up to approximately 10 acre-feet of water
would be required per year for module washing and maintenance. The Project will be consistent
with Maricopa County’s water and wastewater treatment programs during all phases of the
development.
Underground wet/dry utility service or transmission lines within adjacent right-of-way will be
solely at the developer’s expense. Required on-site water and wastewater service and/or
treatment for construction, operations, and maintenance, activities will be the sole financial
burden of the developer. Required services and the developer’s plan of provision will meet
county and state requirements for water and on-site wastewater disposal criteria, permitting,
and monitoring standards.
IV.
ADVERSELY IMPACTING PLANNED USES BECAUSE OF
INCREASED TRAFFIC.
Existing and planned uses surrounding the site which are dependent on the surrounding
transportation system are not anticipated to be impacted due to increased traffic. Planned uses
on-site will not be adversely impacted due to increased traffic. Increased traffic will be limited
to construction and implementation activities associated with this Project and not from others.
The Project will keep existing access points to nearby owners open and available during the
construction phases. During the construction, minor increases are expected for each phase of
Project construction; therefore, per the MCDOT Traffic Impact Manual, a traffic statement will
be required in support of the necessary zone change application and review process. A traffic
statement is a scaled down and simplified version of the traffic impact study and is intended for
smaller Projects that will have lesser impacts on existing traffic as compared to the larger type
of master plan developments. At that time, a clearer Projection of traffic impacts will be
available which will consider construction and operational ADT, construction haul routes,
necessary ROW dedications, and road improvements.
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V.
AFFECTING THE LIVABILITY OF THE AREA OR HEALTH
OR SAFETY OF PRESENT AND FUTURE RESIDENTS.
The General CPA will not adversely affect the livability of the area or health or safety of present
and future residents of the area. As previously discussed, there are relatively few residences
in the area. Site preparation, construction, or operation will not include any hazardous activities,
materials, processes, or outputs. Noise impacts would be limited construction activities during
specified construction hours. Fugitive dust control will be achieved during construction and
operational periods by implementation of proper grading, erosion control measures, and BMP’s
to include appropriate dust control and mitigation of dust on unpaved roads. Standard
operational activities conform to applicable noise ordinances. Fire hazard and wildfire
mitigation will be addressed with the plan of development. The Harquahala Flats Energy
Storage Project will comply with all applicable local and county fire laws and regulations. All
reasonable measures will be taken to prevent fires on the site including the control or
suppression of weeds. If necessary, all weed control would be in compliance with county
regulations. The General CPA will not result in undue or unmitigated social, visual, traffic, air
quality, water quality, or other impacts which may have a disproportionate affecting the livability
of the area.
VI.
ADVERSELY IMPACTING THE NATURAL ENVIRONMENT
OR SCENIC QUALITY OF THE AREA IN CONTRADICTION
TO THE PLAN.
Given the Project site location, adjacent to the busy Interstate 10 thoroughfare, and the
significant amount of similar BESS and solar project approvals in the surrounding area, is not
anticipated that the proposed land use will generate adverse impacts to the natural
environment or the scenic quality of the area.
The Project team will conduct necessary onsite investigations and implement appropriate
protective measures as needed for biological resources to either avoid or mitigate impacts to
the natural environment, in coordination with the Arizona Game and Fish Department (AZGFD).
The Project team recognizes that appropriate coordination, proper planning, and
implementation of best management practices allow projects to be developed that avoid,
minimize, or mitigate potential impacts to wildlife and recreational access during development
and operation of the facilities. The Project team will coordinate with AZGFD through the review
of the zone change and plan of development to minimize any potential impacts to the
surrounding wildlife including proper treatment or preservation of drainage ways and wildlife
corridors. Based on similar surrounding approvals, AZGFD will recommend surveys and
monitoring to identify the species in the area and best management practices will be introduced
to address potential impacts and safety.
As discussed in the transportation sections, no major offsite road or transportation network
improvements are required to support the Project. Dust control measures will be provided to
protect air quality during construction activities. Ground disturbing activities may also require
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dust mitigation, erosion control BMPs, and select soils stabilization or enhancement where
existing erosion is encountered to maintain compliance with local, state, and federal air and
water quality standards.
The site is predominately flat limiting the need for excessive grading for access, supporting
accessory equipment or storage structures. Construction activities will implement accepted
BMP’s for BESS facility development, which include minimum ground disturbance and non-
disturbance of existing low-lying vegetation and vegetation for erosion control purposes.
Vegetation may require mowing to heights approved by the fire district or other environmental
agencies to maintain appropriate levels of fire mitigation and erosion control.
The site will have minor visual impacts to surrounding areas and properties. The site will be
secured with a minimum 6-foot fence to provide separation and security. Details of proposed
fencing will be provided with subsequent zone change and plan of development applications
and finalized through coordination and input from residents and impacted property owners.
The surrounding area has a few sparsely distributed residential land uses. The rest of the
surrounding area is characterized by active and passive agricultural land uses, Bureau of Land
Management (BLM) and Arizona State Land Department (ASLD) owned and managed lands,
natural gas-powered electric generation facilities, solar powered electric generation facilities,
and native desert lands. The predominant surrounding private land uses within the area is
Utilities as designated by approved Comprehensive Plan Amendments which have changed
the underlying future land uses from Rural Densities (0-1) to Utilities.
No adverse or otherwise unmitigated impacts to the natural environment or scenic quality of
the area are anticipated.
The site will be surveyed prior to construction activities to identify plant/vegetation species
which are protected by the Arizona Department of Agriculture under the Arizona Native Plant
Law. Protected plant life and/or vegetation will be relocated or otherwise salvaged. All activities
associated with the removal, relocation, or sale of protected plants/vegetation will comply with
the notice requirements of Title 3, Chapter 3, Title II, of the Arizona Administrative Code.
Additional detailed analysis of environmental impacts will occur with pending zone change and
plan of development submittals. Any identified impacts will be evaluated together with Planning
and other staff within affected local, state, federal regulatory agencies and corresponding
county departments and agencies, and participating stakeholders to identify appropriate
mitigation strategies and/or other acceptable offsetting measures. The Project will maintain
compliance with applicable Maricopa County Air Quality Department permitting and operational
standards, including conformance with U.S. Environmental Protection Agency (EPA), and
Arizona Department of Environmental Quality.
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D. WHETHER THE AMENDMENT IS CONSISTENT WITH OVERALL
INTENT OF THE COMPREHENSIVE PLAN:
Maricopa County’s original Comprehensive Plan was adopted in 1997 as a sensible approach to
addressing the regions fast paced growth and associated development issues. Additionally, the
Tonopah/Arlington Area Plan, adopted in 2000 and updated to follow the direction of the
Comprehensive Plan. A lot has changed since these adoptions, including a relevant update to introduce
energy efficiency and renewable energy into the plan into the Comprehensive Plan in 2007, and the
county looks to build on the past and lessons learned to experience continued smart growth and
achieve a healthy, vibrant and prosperous future. This can be seen throughout the county’s current
Vision 2030 Comprehensive Plan, which is a planning mechanism that looks to balance this future
growth with a high quality of life. The Comprehensive Plan looks to achieve this balance by providing
policies and recommendations on how to protect public health and safety, promote stable economic
growth, maintain a healthy environment, provide adequate community services, and ensure that tax
money is spent efficiently. These policies and recommendations also guide Maricopa County’s
decisions regarding future development, and for when changes to this plan are justified.
Applicant initiated changes to the comprehensive plan, like this change in land use designation, may
occur with Board approval to account for changing conditions provided that such revisions benefit the
county as a whole. This benefit can be weighed through the goals and policies of a series of plan
elements, which each address a subject that affects the county’s quality of life. While each element is
distinct, combined they reinforce the county’s strategic priorities and the core principles of Vision 2030,
and promote consistent interpretation and implementation of its policies and recommendations.
Consistent with the county’s core principles, this land use change helps support the implementation of
Maricopa County’s mission statement and strategic priorities by providing fiscally responsible
alternative energy services and effective and efficient infrastructure to implement delivery of services
that help promote and contribute to a healthy community that residents can enjoy. The General CPA
will maintain the county’s comprehensive plan approach to ensure that the land use request is
understandable, measurable, consistent, practical and promotes efficiency.
This narrative, and more specifically the goal and policy analysis below, lays out the expectations for
future growth and development of the utilities designation, which promote an efficient use of land,
energy and financial resources. Specifically, the renewable energy and solar uses are discussed
throughout Vision 2030 responding to Maricopa County’s ability to be one of the most productive spots
int the world for solar energy generation as discussed in the plan. These references provide measurable
policies and strategies to further the Economic Growth, Water Resources and Energy elements, as
described below, while complementing the growth and development related issues and goals of the
remaining plan elements. Overall, this approach allows the Project to consider the county’s past
decisions provided within Vision 2030 to provide practical and informed decisions to avoid future
problems.
The Project meets the overall intent of the Maricopa County Comprehensive Plan Vision 2030 by
supporting the future need in renewable energy, which has been identified as a strategic priority, that
benefits the region and county as a whole. Additionally, this Project will improve the quality of life as
identified in the goals and policies of the Comprehensive Plan as discussed in the following section.
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E. THE EXTENT TO WHICH THE AMENDMENT IS CONSISTENT WITH
THE SPECIFIC GOALS AND POLICIES CONTAINED WITHIN THE
PLAN.
Maricopa County’s Vision 2030 Comprehensive Plan considers growth-related topics that will affect the
county’s future. The following nine (9) plan elements, which include the four (4) Tonopah/Arlington Area
Plan elements (Land Use, Transportation, Environment, Economic Growth), examine key issues that
shape the goals and policies that Maricopa County uses to implement its mission, vision, strategic
priorities and make informed and effective decisions.
Land Use
Transportation
Environment
Economic Growth
Growth Areas
Open Space
Water Resources
Energy
Cost of Development
Harquahala Flats Energy Storage Project and the Utilities land use designation are affirmed by many
of the goals, objectives, and policies identified within these identified plan elements. The relevant goals,
objectives, and policies contained in the Comprehensive Plan are listed below with specific examples
and guarantees of how each is relevant to the proposed use and why it is consistent.
LAND USE GOALS AND POLICIES
COMP PLAN ELEMENT
(GOALS/POLICIES)
CPA CONSISTENCY/JUSTIFICATION
Land Use Goal #3: Protect
public health, safety and well-
being
Harquahala Flats Energy Storage Project is a low impact land
use, consistently found in the area, that provides renewable
energy storage to the region. The Project requires minimal water
usage, minimal traffic, minimal operational employment or activity
and no wastewater. Additionally, it improves air quality and will
provide necessary ROW dedications, circulation, screening, and
appropriate buffers. Altogether, this passive land use will help
contribute to the public health, safety and well-being of the area.
Land Use Policy #7: Maricopa
County supports coordinating
land
use
and
infrastructure
planning with state agencies,
counties, and municipalities.
The process requires ongoing coordination with local, state, and
federal agencies to ensure protections of public services, utilities,
infrastructure, and natural resources. Coordination is either
expected or has occurred directly with Maricopa County Planning
and Zoning, Environmental Services, the Maricopa County
Department of Transportation, and Arizona Game and Fish
Department (AZGFD). Feedback from state agencies, other
counties and municipalities located in close proximity to the
Project will be received as well through Maricopa County’s
enhanced notification process. Additional coordination will occur
both on this site and with the associated gen-tie with these groups
in addition to the State Historic Preservation Office (SHPO) and
Arizona Department of Agriculture (AZDA). The coordination
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includes preparation of necessary reports and considerations for
the provision as well as protection of natural resources and public
services including, but not limited to, water resources
(ground/surface water supplies), flora and fauna impacts, air and
water quality, and stormwater impacts, open spaces, buffering
and screening, and transportation facilities and rights-of-way.
Land Use Policy #20: Maricopa
County supports reducing the
impacts
of
new
urban
development on existing rural
land uses and agriculture.
The Project is a land use that is already found in the surrounding
area, reducing the impact on nearby agricultural and rural land
uses.
Land Use Policy #22: Maricopa
County supports reducing the
impacts of new development on
environmentally sensitive areas,
including native flora and fauna
habitat and corridors.
The Project does not include environmentally sensitive areas
requiring avoidance or mitigation that we are aware of at this time.
All development activities will remain compliant with applicable
environmental regulations requiring flora/fauna habitat and/or
environmental protection or relocation. Ongoing coordination with
the appropriate agencies, including AZGFD, SHPO and AZDA,
throughout the Project life cycle will ensure appropriate site
treatments
and
regulatory
compliance
with
applicable
environmental policies, protocols, and regulations.
TRANSPORTATION GOALS &
POLICY CONSIDERATIONS
CPA CONSISTENCY/JUSTIFICATION
Transportation
Goal
#1:
Promote and protect public
health
through
a
safe
transportation system.
One of Maricopa County’s strategic priorities is creating a safe,
efficient and effective transportation system. Harquahala Flats
Energy Storage Project will further this priority by addressing
some of their related concerns specific to the preservation of road
alignments and air pollution. The Project will be responsible for
ROW preservation of the necessary roadway alignments, as
indicated by MCDOT from its respective boundaries to comply
with the Maricopa County Transportation Plan and road/ROW
dedication standards of the county. Any exceptions will be
negotiated with MCDOT and authorized by the MC BOS to
memorialize terms of negotiated dedications, preservation, and/or
and deferments or exemptions. Because no full-time employees
are proposed on-site, outside of the limited construction traffic,
Harquahala Flats Energy Storage Project provides a use that will
limit automobile usage and reduce air pollution.
Transportation
Goal
#2:
Contribute to a safe, seamless
and
effective
transportation
system.
The Project will support a safe, seamless, and effective
transportation system by preserving required ROW in support of
future road alignments as coordinated with MCDOT in a manner
consistent with Departmental planning objectives and the
Maricopa County Transportation Plan.
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Transportation
Goal
#3:
Coordinate land use decisions
with transportation investments
to help the county exercise
sound financial management
and build the county’s fiscal
strength.
All transportation improvements required to support the planned
use, or any expansion thereof will be borne solely by the
developer, subject to all required agreements, financial
assurances and/or performance bonds.
Transportation
Policy
#11:
Maricopa
County
supports
National Ambient Air Quality
Standards
(NAAQS)
compliance.
The Project will maintain compliance with National Ambient Air
Quality Standards throughout development phases. Operation of
the Project will result in lower overall emissions.
Transportation
Policy
#12:
Maricopa
County
supports
improving low volume dirt roads
as directed by its PM-10 Dust
Abatement Program.
The Project will maintain compliance with the permitting and
operational standards of the Maricopa County Air Quality
Department dust control requirements as governed by activities
regulated by a dust control permit or Rule 310.01.
ENVIRONMENTAL GOAL AND POLICY CONSIDERATIONS
COMP PLAN ELEMENT
(GOALS/POLICIES)
CPA CONSISTENCY/JUSTIFICATION
Environmental
Goal
#1:
Provide regional leadership to
promote all aspects of regional
environmental quality.
One of the reasons Maricopa County supports state and local
efforts to attract solar research and development to this region is
due to the environmental benefits. Harquahala Flats Energy
Storage Project would further Maricopa County’s potential to be a
leader in renewable energy research and development, with
respect to solar energy storage, and would benefit their Green
Government Program to help protect the environment with a use
that promotes low water usage and better air quality. Additionally,
throughout the Harquahala Flats Energy Storage Project
approvals, reports, plans, and permits will be prepared, for all on-
site and off-site Project activities, to identify areas of
environmental concern, demonstrate proposed methods of
mitigation and compliance, and identify compliance with
environmental performance criteria.
Environmental Policy #2: To
help
improve
air
quality
Maricopa
County
supports
balanced and efficient land use
patterns
where
employment,
retail and residential land uses
are proximate rather
than separate.
Harquahala Flats Energy Storage Project supports improved air
quality by proposing an alternative energy use that decreases
emissions that result from electricity produced by fossil fuels.
Compared to other power producers, solar powered plants and
associated BESS developments significantly decrease carbon
dioxide emissions and eliminate sulfur, nitrous oxides, and
mercury emissions generated by conventional electric generation
facilities. Additionally, this Project which will treated to reduce
potential fugitive dust will improve local air quality impacts from
fugitive dust emissions.
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Environmental Policy #3:
To help protect water quality
Maricopa
County
supports
compliance with its Drinking
Water program and its Water
and
Wastewater
Treatment
program.
The Project as proposed is consistent with and will maintain
compliance with Maricopa County Drinking and Wastewater
Treatment program including water supply of the Maricopa
County Environmental Health Code. As proposed, drinking water
will be delivered by truck. If a local well is required for water use,
such well will comply with local and state permitting, operations,
monitoring, and recharge requirements. The Project, as
proposed, will not have wastewater demands or discharge. A
septic system will be used if an O&M building is required.
Environmental
Policy
#4:
Maricopa
County
supports
innovative Project design and
development techniques that
protect and mitigate damage to
important
plant
and
animal
habitat and migration corridors.
The Project will be designed to minimize, avoid, and/or mitigate
negative impacts to flora and fauna habitat and wildlife migration
corridors during implementation and operational activities.
Comments from the Arizona Game and Fish Department
(AZGFD) will be addressed in a manner consistent with the intent
of this policy, which may include preservation and/or relocation of
impacted flora and/or fauna species. Best management practices
will be employed to address flora/fauna impacts.
Environmental Policy #5: As
directed by SHPO and Arizona
Game and Fish Department,
Maricopa
County
supports
cultural resource and biological
surveys being completed – and
needed
mitigation
measures
established – prior to new
development.
Cultural and biological reporting and surveys associated with this
Project, if required by the State Historic Preservation Office
(SHPO) and AZGFD, will be submitted with the zone change and
plan of development application to identify sensitive areas
requiring protection, preservation, and/or mitigation of impacts to
respective natural, biologic, and/or cultural resources. Mitigation
identified by these or by the respective agency’s staff or other
guidance documents will be adhered to during implementation,
and operation of the use.
ECONOMIC GROWTH GOAL AND POLICY CONSIDERATIONS
COMP PLAN ELEMENT
(GOALS/POLICIES)
CPA CONSISTENCY/JUSTIFICATION
Economic Growth Goal #1:
Contribute
to
an
effective
regional economy.
Economic Growth Policy #5:
Maricopa
County
supports
programs that attract a variety of
Basic Sector industry clusters
that
have
long-term,
stable
growth prospects.
The physical development of the site will employ hundreds of
specialized construction and skilled trade workers and laborers
from unincorporated areas and incorporated municipalities within
Maricopa
County.
Construction
activities
will
generate
employment
opportunities
for
qualified
workers
over
a
construction period which is anticipated to occur from
approximately late 2025 to mid-2028. Local businesses including,
but not limited to retail, food service, gas station/convenience, and
hospitality businesses will be supported by workers commuting to
the site or lodging near the site for short/long terms during their
respective periods of construction activities. No construction
camps or on-site housing are proposed during the implementation
(construction) phase of the Project. No on-site security or
maintenance housing is proposed during the operational phase of
this development.
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Economic Growth Policy #10:
Maricopa
County
supports
leveraging its solar resource
potential to attract solar-related
industries
and
alternative
energy
research
and
development.
More accessible energy sources will attract energy dependent
employment sectors to the region and allow existing basic sector
industries to reinvest energy savings into expansions, research
and
development,
and retrofitting activities to
increase
productivity in response to growing demands and competition in
the regional and national share of their respective industries.
Increasing the supply of locally generated renewable energy
storage increases the attractiveness of the region on the demand
for technological innovations to meet the demand for additional
skilled and specialized workers. There will also be an increase in
the demand for specialized workers to respond to changes and
innovations in the solar powered generation industry and in the
development of spin off applications in the manufacturing,
transportation, and research/development industries.
GROWTH AREA’S GOAL AND POLICY CONSIDERATIONS
COMP PLAN ELEMENT
(GOALS/POLICIES)
CPA CONSISTENCY/JUSTIFICATION
Growth
Areas
Goal
#1:
Achieve orderly urban growth
that
is
fiscally
and
environmentally
responsible,
protects public health and safety
and
promotes
sensible
annexation patterns.
The Project is located near existing and approved generation
facilities and has convenient access to existing electrical
infrastructure, major transmission corridors, and a major electrical
substation. Proximity to existing transmission lines, corridors, and
easements reduces the Developer’s expenditures to utilize
existing infrastructure and to obtain necessary easements to
interconnect to the electrical grid. Construction and operational
activities will maintain compliance with applicable environmental
criteria, regulations, and permitting to ensure protection of
biologic and natural resources.
Growth
Areas
Policy
#1:
Maricopa
County
supports
consistent implementation of its
urban growth area except in the
noted instances.
The proposed Project is considered an industrial land use that
does not require a corresponding level of urban services and
infrastructure and can be located in rural remote areas. As the
plan recommends, this land use is acceptable outside the urban
growth area. These uses could include electric generating
facilities, proving grounds and test facilities, agriculturally oriented
businesses, and other rural-type industrial uses on a case-by-
case basis.
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WATER RESOURCES GOAL AND POLICY CONSIDERATIONS
COMP PLAN ELEMENT
(GOALS/POLICIES)
CPA CONSISTENCY/JUSTIFICATION
Water Resources Goal #4:
Increase water conservation.
The switch in land use from allowed residential or agricultural
uses to BESS will significantly increase water conservation in the
county. The project team recognizes that the proposed site
receives a high degree of solar radiation and that water supplies
in the vicinity are limited. The Project will implement water
conservation measures while utilizing water-efficient technology.
Construction Peak Water Usage and Operations & Maintenance
Water Usage would be significantly less than any allowed
residential or agricultural use.
Water Resources Policy #2:
Maricopa County supports water
conservation techniques in the
planning and design of new
development.
The Project will include a comprehensive Water Conservation
Plan with established BMPs for water conservation. The Project’s
water-conscious design and implementation is consistent with the
applicable water goals and policies of the Comprehensive Plan.
Water Resources Policy #4:
Maricopa
County
supports
compliance with its Drinking
Water
and
Water
and
Wastewater
Treatment
Programs.
Drinking water will be delivered by truck. If a local well is required
for water use, such well will comply with local and state permitting,
operations, monitoring, and recharge requirements.
The Project will maintain compliance with Maricopa County’s
wastewater treatment programs during the construction activity
period. The Project as proposed will not have wastewater
demands or discharge. A septic system will be used if an O&M
building is required. Alternatively, portable restroom facilities will
be provided for employee use during the implementation and
operational phases.
Water Resources Policy #5:
Maricopa County supports low
water
use
solar
electric
generating technologies.
Harquahala Flats Energy Storage Project will require very little
water except for maintenance equipment support. This water will
either be hauled to the site during construction and operation or
obtained from wells permitted through the Arizona Department of
Water Resources (ADWR), as needed. Water hauled to the site
would be from permitted sources.
Water Resources Policy #7:
Maricopa County supports low
water use and drought tolerant
landscaping.
If landscape treatments are required to provide visual buffering,
they will be selected from drought tolerant xeric species which will
require low water use to establish and maintain.
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ENERGY GOAL AND POLICY CONSIDERATIONS
COMP PLAN ELEMENT
(GOALS/POLICIES)
CPA CONSISTENCY/JUSTIFICATION
Energy Goal #1:
Provide leadership to promote
regional environmental quality.
Harquahala Flats Energy Storage Project will have a long-term
environmental impact of improving air quality by supporting solar
energy production which reduces the emissions associated with
conventional electric energy generation. The county has adopted
environmental performance standards intended to preserve and
sustain biologic, cultural, and environmental resources of the
region which are evidence of the county’s regional leadership role
in the promotion of environmental quality.
Energy Goal #2:
Make Maricopa County a leader
in alternative energy research
and development.
Harquahala Flats Energy Storage
Project provides the
opportunity to implement, test, and evaluate the efficiencies of the
most current battery energy storage systems. Evaluation of their
operational performance is key to the research and development
of more efficient equipment and related processes. An
operational facility provides opportunities to implement advances
in the associated technologies over the life of the Project.
Approval of the facility provides opportunities to test storage
systems in response to increasing demands for the use of stored
energy.
Energy Policy #6:
Maricopa County supports being
a
responsible
leader
in
alternative energy research and
development.
Harquahala Flats Energy Storage Project will be reflective of the
Maricopa County Board of Supervisor’s regional and statewide
leadership in the attraction, promotion, and delivery of renewable
energy resources and infrastructure.
COST OF DEVELOPMENT GOAL AND POLICY CONSIDERATIONS
COMP PLAN ELEMENT
(GOALS/POLICIES)
CPA CONSISTENCY/JUSTIFICATION
Cost of Development Goal #2:
New
development
pays
its
proper and reasonable share of
the costs of new infrastructure,
services
and
other
public
improvements.
All Project costs, including, but not limited to, on-site
improvements, gen-tie line infrastructure and connections,
collection lines, off-site road improvements, and water and
wastewater treatment service, shall be borne solely by the
Developer.
Cost of Development Policy
#2: Maricopa County supports
recouping
the costs
of
its
products and services without
unfairly burdening those most in
need
of
its
products
and
services.
All development costs will be borne solely by the developer,
including, but not limited to, applicable fees for service, impact
fees, performance bonds and sureties, and property taxes.
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OPEN SPACE GOAL AND POLICY CONSIDERATIONS
COMP PLAN ELEMENT
(GOALS/POLICIES)
CPA CONSISTENCY/JUSTIFICATION
Open Space Goal #1: Provide
regional leadership to promote
environmental quality, including
the preservation of open, natural
park and recreation lands.
The Project is located away from, and will not impact, Maricopa
County’s regional parks, trails, or other public recreation.
Furthermore, this Project would enable the county to site utility-
scale solar generation and storage uses near existing electrical
infrastructure and similar uses, in an area that development would
result in limited impact to open space lands and would
demonstrate efficient, orderly growth. In addition, the Project
would be able to store renewable energy that would result in
improved air quality through reduced emissions for electric
generation, allowing Maricopa County to provide regional
leadership in promoting environmental quality through improved
air quality in the County.
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F. COMPREHENSIVE PLAN AMENDMENT MAP EXHIBIT
PROPOSED LAND USE: UTILITIES
EXISTING LAND USE: RURAL DENSITIES (0-1)
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G. COMPREHENSIVE PLAN AMENDMENT LEGAL DESCRIPTIONS
EXHIBITS
(Legal descriptions for the parcel are available in a separate deed attachment.)
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APPENDIX - A ‘SITE PARCELS’
One (1) parcel that constitute the +/-321.10-acre Site
#
Assessor
Parcel No.
(APN)
Owner
CPA Acreage
(±AC)
Township &
Range
Section
Deed
1
506-31-015
PETERS RONALD
VINCENT/CHRISTOPH
ER DALE/REBECCA
E/TIMOTHY/THERESA/
NICHOLAS/KATHERIN
E/GIFFORD MARINA C
321.10
2N 7W
18
20080702007
kimley-horn.com
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Exhibit A - Vicinity Map
General Location: The proposed site is located roughly 4 miles west of Tonopah/15 miles west of
Buckeye on a vacant +/-321-acre privately owned parcel, which straddles Interstate 10 in the northeast
quarter of section 18, township 2 north, range 7 west in unincorporated Maricopa County, Arizona.
HARQUAHALA FLATS ENERGY
STORAGE PROJECT
CASE #: Z250001 & CPA250001
REQUEST: Zone Change with Overlay from RU-43 to IND-2
IUPD on Approximately 321.10 Acres
NARRATIVE REPORT FOR
01-10-2025, Revised 03-04-2025
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TABLE OF CONTENTS
1.
PURPOSE OF REQUEST .............................................................................................................. 3
2.
DESCRIPTION OF PROPOSAL .................................................................................................... 3
2.1 Site Summary Information: .......................................................................................................... 3
2.2 Proposed Uses (Summary): ......................................................................................................... 4
Hours/Days of Operation: ................................................................................................................ 4
Number of Employees: .................................................................................................................... 4
Description/Location of Buildings: ................................................................................................... 4
Color Palette: ................................................................................................................................... 4
Sign Details: .................................................................................................................................... 4
Screening Wall/Fence Details and Location: .................................................................................. 4
3.
RELATIONSHIP TO SURROUNDING PROPERTIES ................................................................... 5
Existing Surrounding Solar (Utility) Land Use Approvals ................................................................ 6
4.
LOCATION AND ACCESSIBILITY ................................................................................................ 7
Location: .......................................................................................................................................... 7
Access: ............................................................................................................................................ 7
5.
CIRCULATION SYSTEM ................................................................................................................ 8
Off-site Circulation (Access): ........................................................................................................... 8
On-site Circulation ........................................................................................................................... 8
Parking and Loading ....................................................................................................................... 8
6.
DEVELOPMENT SCHEDULE ........................................................................................................ 8
7.
COMMUNITY FACILITIES AND SERVICES ................................................................................. 9
8.
PUBLIC UTILITIES AND SERVICES ............................................................................................. 9
TABLES
1. Industrial Unit Plan of Development ……………………………………………………………...….12
PROJECT TEAM
PLANNING/ENTITLEMENTS/ APPLICANT/
DEVELOPER
ENGINEERING
REPRESENTATION
HARQUAHALA FLATS ENERGY
KIMLEY-HORN
PEW & LAKE PLC
STORAGE, LLC
CONTACT: KEITH NICHTER
CONTACT: RALPH PEW
CONTACT: JAMES JACKSON
(PLANNING), SHANE
480.461.4670
JAMES.JACKSON4@NEXTERAENERGY.COM JOHANNSEN (ENGINEER)
RALPH.PEW@PEWANDLAKE.COM
602.313.7206
KEITH.NICHTER@KIMLEY-HORN.COM
SHANE.JOHANNSEN@KIMLEY-HORN.COM
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1. PURPOSE OF REQUEST
“Pew & Lake, PLC (the “Applicant”), on behalf of Harquahala Flats Energy Storage, LLC, a wholly-
owned, indirect subsidiary of NextEra Energy Resources (the “Developer”), with the permission of the
Property Owners identified in a separate appendix, request approval of a Zone Change with Overlay
(rezone) from RU-43 (Rural) to IND-2 IUPD (Light Industrial) Zone for the Harquahala Flats Energy
Storage Project (“Project”) on (1) parcel / approximately ±321 acres. The Project approval will allow for
future photovoltaic solar energy generation and a battery energy storage (BESS) system, step-up
substation and associated infrastructure.
2. DESCRIPTION OF PROPOSAL
2.1 Site Summary Information:
The ±321 acres included are inclusive of the following one (1) underlying parcel:
#
Assessor Parcel No. (APN) Owner
Acreage
Township & Range
Section
1
506-31-015
PETERS RONALD VINCENT/
CHRISTOPHER DALE/REBECCA
E/TIMOTHY/THERESA/NICHOLAS/KATHE
RINE/GIFFORD MARINA C
321.10
2N 7W
18
The Developer proposes to construct, operate, and maintain a battery energy storage system and
associated infrastructure for the Project.
The initial development will consist of a BESS facility, which stores energy for later use improving the
reliability, availability, and efficiency of the power supply. Additionally, the 500 kV step-up substation
will accommodate the future gen-tie connection that will link the site to the grid via overhead electrical
structures, completing connection to the existing APS Delaney substation located +/-2 miles to the
southwest. The site will also include one or more small buildings to house telecommunication
equipment and allow for future BESS and/or solar generation on the northern portion of the property.
The proposed rezone in support of the ±321-acre Project will not adversely impact the planning area in
part nor portion. The sites solar and BESS elements will be developed in two phases with the first being
the BESS facility in the parcel south of I-10 and the future second phase, being the solar/additional
BESS element, developed in the parcel north of I-10 with details to be defined in a future Plan of
Development (POD) application. In conjunction with this rezone request, a proposed General
Comprehensive Plan Amendment (CPA) application will be submitted to modify the Projects current
land use designation from ‘Rural Densities (0-1)’ to ‘Utilities’. Both applications will allow development
of the Project. The Project will be consistent with the components of the Maricopa County
Comprehensive Plan, which include, but are not specifically limited to: land use; public transportation
system improvements; drainage and/or stormwater management; environmental considerations (air &
water quality, potable water & wastewater treatment), areas of geologic concern, hazard, and/or
significance; plant and wildlife habitat/migration environs and/or patterns; aviation and military
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installation operations and flight paths/patterns; economic growth; growth areas; open space, water
resources; energy; and/or the cost of development.
2.2 Proposed Uses (Summary):
Hours/Days of Operation:
The site will be in operation and/or production 24 hours a day, seven (7) days per week. Solar
generation activities in the area would be limited to daytime (daylight) hours which vary seasonally but
the energy storge activities and operations on this site will be continuous and energy transmission into
the power grid will occur on demand as needed throughout both the daytime and nighttime hours.
Number of Employees:
Construction activities are anticipated to employ up to 250-400 in varying phases in the construction,
contracting, administrative, and Project management fields during the construction and implementation
phase. Operation of the site will not require full-time employees on site. Routine maintenance activities
will be performed by up to 10 full time employees based out of offsite regional facilities for equipment
repair and replacement as needed.
Description/Location of Buildings:
Smaller communication and electrical equipment could be located among future PV array fields.
Electrical and telecommunication equipment may be contained within housing units or cabinets that are
a manufactured protective outer covering for the internal equipment. Self-enclosed units include small
telecommunications equipment cabinets and Battery Energy Storage System (BESS) equipment
cabinets/shelters. BESS cabinets/shelters will be located near the BESS system components housed
in prefabricated steel containers located.
Operations & maintenance (O&M) building(s) will be provided for the Project located near the BESS
area and substation. Site sewer for this building(s) will be septic and the water will be either hauled and
provided via above ground tank or via well.
Color Palette:
All materials coatings, finishes, and colors, where practicable, will be selected to blend facility
components to the natural setting. Selection of color palettes for electrical cabinets will be selected
from factory specifications and options provided by the respective manufacturers. Color palette
selection will conform to generally accepted and adopted industry standards for BESS equipment
support structures. Final color selections will seek to minimize heat absorption and glare and blend with
surrounding natural environment so far as is practicable.
Sign Details:
Signage will be limited to site identification signs, OSHA approved safety signage, and security signage
in accordance with Chapter 14 of the Maricopa County Zoning Ordinance.
Screening Wall/Fence Details and Location:
As discussed below, the property is surrounded mostly by vacant and agricultural lands with some rural
residential to the southeast and the site bisected by Interstate 10. To ensure proper site security, related
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to these surrounding uses, the site perimeter will be enclosed with chain link fence (6 feet in height with
the addition of 1 foot’ of barb wire) with gates where needed along the perimeter of the Project.
Security Lighting:
Security lighting will be limited to motion activated lighting associated with the BESS yard(s) and other
security sensitive areas such as entry gates, and parking areas, as shown on the Plan of Development.
All lighting installed will be directed downward and into the site, in compliance with Maricopa County
Zoning Ordinance Article 1112, to ensure lighting will not be cast onto neighboring properties. Lighting
required for safety operations during nighttime operational or maintenance activities will be provided by
the associated staff/employee personnel.
3. RELATIONSHIP TO SURROUNDING PROPERTIES
The Project is surrounded mostly by vacant Arizona State Land Department property to the west and
south, Bureau of Land Management property to the north and east and private land to the east. West
Phoenix Estates, a mostly vacant residential subdivision (1969), is located to the southeast. Adjacent
property owners will be notified of the Project, and efforts will be made to identify and address any
concerns. The Project has been designed with buffering in mind, with large BESS setbacks (minimum
100’ per NFPA 855), and will be enclosed by perimeter security fencing along the property edges and
adjacent rights of way. No fencing will impede Interstate 10 or otherwise enclose existing roads adjacent
to the Project boundary.
Exhibit B – Adjacent Properties
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Surrounding Adjacent General Land Descriptions
Direction
Zoning
Land Use Designation
Land Use
North
RU-43
Rural Densities (0-1) (BLM)
Agricultural/Vacant
East
RU-43
Rural Densities (0-1) (BLM/Private)
Agricultural/Vacant
South
RU-43
Rural Densities (0-1) (ASLD) & Large Lot
Residential (1-2) (Private)
Agricultural/Vacant
West
RU-43
Rural Densities (0-1) (ASLD)
Agricultural/Vacant
Existing Surrounding Solar (Utilities) Land Use Approvals
The surrounding region is characterized by active and passive agricultural land uses, solar powered
electric generation facilities, native desert lands and rural residential. The dominant private land use
within the area surrounding the site is vacant desert, agriculture and solar generation facilities, which
occurs on parcels or combinations of parcels totaling several hundred to thousands of acres in irregular
configurations to the west and southwest. Other surrounding land uses include publicly owned and
managed Local, State, and Federal Lands. These include lands controlled by the Maricopa Flood
Control District, Arizona State Land Trust, and Bureau of Land Management. Other surrounding land
uses include vacant and active agricultural uses with limited and sparse distribution of privately owned
parcels used for residential purposes within the surrounding area. Additionally, Luke Air Force Base
(LAFB) is known to have military training routes out in this area. Under the Department of Defense
(DOD) Clearinghouse process, energy projects greater than 199’ above ground level are required to
go through a Formal Review. The routes in this area already fly over several existing 500kV lines and
fly nearby several large solar projects. Although, the Project team will be proactive in addressing any
potential concerns and will submit under the Informal Review DOD Clearinghouse process during the
zoning process.
The Harquahala Flats Energy Storage Project looks to support nearby proposed solar voltaic sites by
providing storage capacity for the energy produced by these other energy-based projects. As a result,
the proposed use is compatible with other similar approved and implemented solar projects to the west,
south-west and the region as a whole. Associated facilities within this area include approved CPA’s
and rezones for Utility (solar) land uses, PV solar generation facilities, utility corridors, transmission
lines and a utility substation. Many of the related parcels nearby the Project have been subject to
previous CPA approvals. Some of the other nearby projects are as follows:
Project:
Location (Township/Range):
Maricopa Solar and Storage Project
T1N R8W; T1N R9W; T2N R8W; T2N R9W
Harquahala Sun
T1N R9W
Harquahala Sun II and III-V
T1N R8W; T1N R9W
Saddle Mountain Solar
T1N R9W
Eagletail Solar Farm
T1S R9W
Almeria Solar
T2N R8W
Sun Valley North & South
T2N R8W
Areva Solar AZ II
T2N R7W
Papago Solar
T2N R8W
Tonopah Photovoltaic
T2N R8W
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4. LOCATION AND ACCESSIBILITY
Location:
The Project is located in the northeast quarter of section 18, township 2 north, range 7 west in
unincorporated Maricopa County, Arizona. The site is roughly 4 miles west of Tonopah and 15 miles
west of Buckeye. The site is bounded by the W. Bethany Home Road alignment on the north, N. 443rd
Avenue on the east, W. Camelback Road on the south and is bisected by the Interstate 10 (I-10)
Highway. The portion of the site south of I-10 will be utilized for the substation and BESS uses with the
portion to the north being reserved for future alternative energy development.
Access:
The Project straddles Interstate 10 (I-10), approximately 22 miles west of the State Route 85 (SR
85) connection to I-10.
Regional access to the site will be from the south via I-10 to the 411th Avenue exit, west on W Indian
School Rd, then north on 443rd Ave to the southern portion of the site on the south side of I-10.
Access to the site will be via the existing the sixty-five (65) half ROW from West Phoenix Estates
Plat, no full ROW present and 130’ full ROW 443rd Ave and onsite access driveways shown in the
site access illustration below (Exhibit C – Site Access).
Exhibit C – Site Access
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5. CIRCULATION SYSTEM
Off-site Circulation (Access):
The site can be accessed most directly from the I-10/411th Avenue Highway interchange. The roadway
network serving the proposed Project starts from the I-10/411th Avenue interchange, connects 411th
Avenue south to W Indian School Road which extends west to the intersection with 443rd Avenue,
turning north to the site. Access will be identified with the zone change and plan of development
applications. Final access locations will be determined in accordance with access management policies
and permitting requirements of Maricopa County.
Residential properties adjacent to the Project area are located north of W Indian School Road, south
of I-10 between 443rd Avenue on the west and 439th Avenue on the east. The Maricopa County
Department of Transportation may request ROW dedications/preservations along the following
alignments:
There would be no significant increase in traffic during the operational life of the Project that would
require road improvements. There would be a relatively minor increase in the level of traffic during the
approximately 12 months required for construction. This increased traffic is expected to be fewer than
250 trips during single peak morning and evening hours, primarily for the delivery of equipment and
supplies and the commuting of the construction workforce. A traffic impact study has been completed
as part of the zone change process associated with the Project. The Applicant has agreed to financial
responsibility for repair of roads used during construction, including bonding for such work, so that there
is not public expenditure for transportation infrastructure associated with the Project.
On-site Circulation
Internal circulation is planned via a network of private maintenance and service drive aisles to provide
vehicular access to the BESS units and associated equipment. The typical 20’ internal drives are being
compacted with decomposed granite (DG), or similar road base material to minimize imperviousness
and stormwater runoff, as proposed with an approved dust control permit from Maricopa County Air
Quality Control. Construction and maintenance of the drives will conform to applicable requirements of
the Maricopa County Air Quality Control Department
Parking and Loading
With no occupied buildings or full-time employees on-site, there is no proposed formal parking spaces
or ADA spaces. During operations maintenance parking, loading, and temporary maintenance staging
will occur within designated area within the BESS yard area. Loading during maintenance activities in
the BESS yard will occur on private 20-foot (typical) all weather surfaced roads.
6. DEVELOPMENT SCHEDULE
Construction of phase 1, south of Interstate 10, is anticipated in late 2025.
Street name:
Existing ½ Width ROW:
Future ROW (Full):
* Future Classification:
443rd Avenue
65’ (Varies)
130’
Local
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7. COMMUNITY FACILITIES AND SERVICES
The Project is located within the community service district boundaries:
Western Maricopa Education Center (MEC) Technical School District (District Ward No. 4)
Tonopah High School (Saddle Mountain Unified District)
Saddle Mountain Unified District No. 90
The Project is not anticipated to generate any adverse impacts to the listed school districts.
8. PUBLIC UTILITIES AND SERVICES
Utility service(s) to the site will be provided by the following providers. No water or wastewater service
is planned. Water for construction purposes will be transported to the site. Drinking water for employees
will be individually provided. No permanent restrooms will be provided. Temporary facilities will be
provided for maintenance activities as needed.
UTILITY/SERVICE
AGENCY/PROVIDER
Water
(N/A) Hauled/well
Sewer
(N/A) Sanitary sewer provided via accessible
portable
restroom
facility
as
needed
for
maintenance activities. In the event that a future
O&M
building
is
built
and/or
permanent
employees are present on the site sewer to be
septic.
Electric Service
Arizona Public Service
Fire Protection (including EMS and Ambulatory
Services)
Arizona Fire & Medical Authority / South County
Fire & Medical District
Police Protection
Maricopa County Sheriff Office
Refuse (Waste Management)
Republic Services
Telephone
American Telephone and Telegraph (AT&T) Co
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HARQUAHALA FLATS ENERGY STORAGE PROJECT –
IUPD MODIFICATIONS TO IND-2 DEVELOPMENT STANDARDS
STANDARD
CATAGORY
IND-2 ZONING
DISTRICT
STANDARD
PROPOSED IND-2
IUPD ZONING
DISTRICT STANDARD
JUSTIFICATION
MAX. HEIGHT
40'
40'
MIN. FRONT
YARD
10'-25'
10'-25', 100’ FOR
BESS
ADDITIONAL SETBACK PROVIDED FOR
BESS.
LANDSCAPING
ARTICLE 901.4.1: ALL
PROPERTIES
ABUTTING A PUBLIC
STREET SHALL
HAVE AN OPEN
SETBACK AREA
WHICH SHALL BE
LANDSCAPED
EXTENDING FOR
THE FULL WIDTH OF
THE PROPERTY
NO LANDSCAPE
STRIP REQUIRED
NO LANDSCAPING PROPOSED.
MIN. SIDE YARD 3'-10'
3'-10', 100’ FOR BESS ADDITIONAL SETBACK PROVIDED FOR
BESS.
MIN. REAR YARD 25'
25', 100’ FOR BESS
ADDITIONAL SETBACK PROVIDED FOR
BESS.
MIN. LOT AREA 6,000 SQ. FT.
6,000 SQ. FT.
MIN. LOT WIDTH 60'
60'
MAX. LOT
COVERAGE
60% MAXIMUM
60% MAXIMUM *
PARKING
REGULATIONS
ARTICLE 1102.1.5:
600 SQ.FT. OF
FLOOR AREA; 5% OF
PARKING SPACES
SHALL BE
HANDICAPPED
PARKING SPACES
NONE REQUIRED
PARKING AREAS WILL BE AVAILABLE
ON THE ALL WEATHER (PRIVATE)
ACCESS ROADS OR AT THE
DESIGNATED PARKING AREA AT THE
BESS YARD. PARKING IS NOT
REQUIRED DURING OPERATION. THE
FACILITY WILL BE UNMANNED DURING
OPERATIONS EXCEPT FOR
OCCASIONAL TEMPORARY SYSTEM
OR FACILITY MAINTENANCE.
PAVING
REQUIREMENTS ARTICLE 1102.7.1
PARKING/PAVING
MATERIAL ALLOWED
TO BE STABILIZED
DECOMPOSED
GRANITE WITH AN
APPROVED DUST
CONTROL PLAN BY
MARICOPA COUNTY
AIR QUALITY
CONTROL.
TRAFFIC WILL BE LIMITED WITHIN THE
PROJECT. PRIVATE ACCESSWAYS
WILL BE CONSTRUCTED OF
COMPACTED AGGREGATE BASE WITH
A STABILIZED DECOMPOSED GRANITE
OVERLAY, PURSUANT TO THE MCDOT
ROADWAY DESIGN MANUAL, TO LIMIT
ANY ISSUES WITH DUST FOR AIR
QUALITY PURPOSES.
Table 1: Industrial Unit Plan of Development
Page 11
kimley-horn.com
1001 West Southern Avenue Suite 131, Mesa, AZ 85210
480 207 2666
LOADING &
UNLOADING
ARTICLE 1103.2 ONE
LOADING AND
UNLOADING SPACE
FOR EACH 10,000
SQ.FT. OF FLOOR
AREA, OR FRACTION
THEREOF, DEVOTED
TO SUCH USE IN
THE BUILDING
NONE REQUIRED
LOADING AND UNLOADING SPACES
WILL NOT BE REQUIRED FOR THE
SITE. THERE WOULD BE NO ROUTINE
DELIVERIES OR SHIPMENTS. A
STAGING AREA IS PROVIDED FOR
RESPONDERS.
SIGHT VISIBILITY
TRIANGLES
NO OBSTRUCTIONS
OVER 2' IN HEIGHT
WITHIN 25'X25' SVTS
NO SVT'S AT
PROJECT SITE
ENTRY/EXIT POINTS,
SECTION LINE, AND
MID-SECTION LINE
INTERSECTING
ALIGNMENTS
FENCING AT INTERSECTIONS WILL BE
OPEN CHAIN-LINKNED AND
THEREFORE VISIBILITY WILL BE
MAINTAINED. ADDITIONALLY, HAVING
NO SVT REQUIREMENT WOULD BE
THE MOST EFFICIENT USE OF SITE
AREA AND MAXIMIZE ENERGY
STORAGE AND GENERATION.
ARTICLE 902.91
ALL USES EXCEPT
FOR PARKING,
LOADING,
UNLOADING OR
STORAGE SHALL BE
CONDUCTED
WITHIN A
COMPLETELY
ENCLOSED
BUILDING
ALL UTILITY USES
PERMITTED
OUTDOORS
THE OPERATING USES OF THE SITE
INCLUDE ENERGY GENERATION AND
STORAGE. SOLAR CANNOT BE
UTILIZED WITHIN ENCLOSED
STRUCTURES; THEREFORE, USES
WILL BE LOCATED OUTSIDE OF
ENCLOSED BUILDINGS. BESS UNITS
ARE ENCLOSED WITHIN CABINETS.
SITE
ENCLOSURE
AND SCREENING
6' CMU WALL
ADJACENT TO
RURAL AND
RESIDENTIAL
ZONING
BOUNDARIES AND
FOR OUTDOOR USE
OF AN INDUTRIAL
NATURE
CHAIN-LINK FENCING
AND GATES SHALL
BE ALLOWED ON
THE PERIMETER OF
THE PROJECT
AS REQUIRED TO ENSURE PUBLIC
SAFETY REQUIRED BY APPLICABLE
ELECTRICAL SAFETY REGULATIONS
AND PROVIDE FOR THE SECURITY OF
THIS INFRASTRUCTURE PROJECT,
THE APPLICANT WILL INSTALL CHAIN-
LINK FENCING (WITH GATES WHERE
NEEDED ALONG THE PERIMETER OF
THE PROJECT). THE APPLICANT
PROPOSES TO USE CHAIN LINK FOR
THE GATES ALSO, WHICH WOULD BE
CONSISTENT WITH OTHER NEARBY
ENERGY GENERATION PROJECTS.
BARBED WIRE
FENCING
BARBED WIRE
ATTACHED TO
FENCES IS
PROHIBITED FOR
FENCES UNDER
8'.
BARBED WIRE
ATTACHED TO
FENCING UNDER 8’
WILL BE
ALLOWED WITHIN
THE
PROPERTY
BOUNDARIES.
A REDUCTION IN THE HEIGHT OF
FENCING WILL IMPROVE THE
AESTHETIC OF THE PROJECT,
REDUCE ENVIRONMENTAL IMPACTS
AND BE MORE COMPATIBLE WITH THE
NEARBY SOLAR AND AGRICULTURAL
USES.
Page 12
kimley-horn.com
1001 West Southern Avenue Suite 131, Mesa, AZ 85210
480 207 2666
MAX ELECTRIC
TRANSMISSION
LINE HEIGHT
120'
150’
A NEW GEN-TIE ROUTE IS REQUIRED
FOR THIS PROJECT AND WHILE THE
MAJORITY OF IT IS OUTSIDE THIS
ZONING BOUNDARY THERE IS STILL
IMPACT TO THE PROJECT SITE WITH
THE CONNECTION TO THE
SUBSTATION(S). UTILITY POLE
HEIGHTS UP TO 150 FEET ARE
REQUESTED BECAUSE
UTILITY STRUCTURES 120 FEET OR
LESS IN HEIGHT MAY BE INFEASIBLE
DUE TO FINAL ELECTRICAL DESIGN
CONSIDERATIONS AND MAY IMPACT
THE SUBJECT ROW/PROPERTIES
MORE, REQUIRING LESS SPACING
AND MORE POLES. THE APPLICANT’S
CURRENT PRELIMINARY,
CONCEPTUAL DESIGNS INDICATE
THAT HIGHVOLTAGE DEAD-END
STRUCTURES UP TO 150 FEET IN
HEIGHT MAY BE REQUIRED AND
COULD RESULT IN LESS IMPACT. THE
APPLICANT REQUESTS THE
FLEXIBILITY TO MAKE THE
NECESSARY ADJUSTMENTS, AS
NEEDED, FOR FUTURE FINAL
DESIGNS. ADDITIONALLY, UNDER THE
DOD CLEARINGHOUSE PROCESS,
ENERGY PROJECTS GREATER THAN
199’ ABOVE GROUND LEVEL ARE
REQUIRED TO GO THROUGH A
FORMAL REVIEW, WHICH THE
PROJECT TEAM HAS PROACTIVELY
SUBMITTED UNDER THE INFORMAL
REVIEW DOD CLEARINGHOUSE
PROCESS.
*DETACHED PV SOLAR ARRAY DO NOT CONTRIBUTE TO THE OVERALL LOT COVERAGE AS
PER ARTICLE 1206.3.2.A. OF THE MARICOPA COUNTY ZONING ORDINANCE.
(The remainder of this page is left intentionally blank)
400'
DRAINAGE ESMT.
100'
DRAINAGE ESMT.
200'
ADOT ROW
200'
ADOT ROW
25'
200'
ADOT ROW
200'
ADOT ROW
731.9'
55' ROW
PRESERVATION
10'
51'
61'
28.1'
200' PROPOSED GEN-TIE ESMT.
443RD AVE
INTERSTATE 10
ACCESS ROAD
O&M SITE
(50' X 60')
SEPTIC SYSTEM
(20' X 20')
SECURITY FENCE
PROPOSED
GEN-TIE
SUBSTATION AREA
RETENTION BASIN S3-B
GATE
SITE ENTRANCE
BATTERY
ENCLOSURE (TYP.)
INVERTER SKID
(TYP.)
CONEX
BOX (TYP.)
LOW FLOW
CROSSING
RETENTION BASIN S3-A
FEMA ZONE A
SECURITY FENCE
BERM
RETENTION BASIN S2
RETENTION BASIN S1
LOW FLOW
CROSSING
ALTERNATIVE
SITE ACCESS
AREA OF FUTURE DEVELOPMENT
FOR PHOTOVOLTAIC
GENERATING PLANT AND BESS
FEMA ZONE A
FEMA ZONE AE
FEMA ZONE AE
FEMA ZONE AE FLOODWAY
25' SETBACK
5' SETBACK
65' ROW
PRESERVATION
65' ROW
PRESERVATION
EQUALIZER PIPE
DRAINAGE CHANNEL
5' SETBACK
350'
24'
(TYP.)
24'
(TYP.)
FIRE WATER TANK
RESPONDER STAGING AREA
RESPONDER STATION
WITH REPORTING PANEL
100' MIN. BATTERY
SETBACK - TYP.
100' MIN. BATTERY
SETBACK - TYP.
100' MIN. BATTERY
SETBACK - TYP.
100' MIN. BATTERY SETBACK - TYP.
VEGETATION AREA
SECURITY FENCE
40' MIN. FLOOD ZONE
SETBACK - TYP.
40' MIN. FLOOD ZONE
SETBACK - TYP.
HARQUAHALA
FLATS ENERGY
STORAGE
©
Contact Arizona 811 at least two full
working days before you begin excavation
Call 811 or click Arizona811.com
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62869
SHANE R.
JOHANNSEN
04
02
25
EX-1
ZONING
SITE PLAN
LEGEND
PROPERTY LINE
EASEMENT LINE
SECTION LINES
EXISTING GRADE CONTOUR
STANDARD CHAIN-LINK SECURITY
FENCE
AREA OF FUTURE DEVELOPMENT
(SOLAR & BESS)
FEMA ZONE A
FEMA ZONE AE
FEMA ZONE AE FLOODWAY
20' INTERIOR ACCESS ROAD
20' ALTERNATIVE ACCESS ROAD
GEN-TIE LINE
BERM CENTERLINE
DRAINAGE CHANNEL CENTERLINE
RETENTION BASIN
DRAINAGE AREA
NORTH
NORTH
VICINITY MAP
PROJECT BOUNDARY
INDIAN SCHOOL RD
443RD AVE
INTERSTATE 10
GEN-TIE ROUTE
DELANEY SUBSTATION
N.T.S
GENERAL NOTES
MARICOPA COUNTY CASE NUMBER: Z250001/CPA250001
PRELIMINARY
NOT FOR CONSTRUCTION
Page 1 of 1
Larry Morden, PE
Planning & Development
301 W. Jefferson St., Suite 170
Phoenix, Arizona 85003
Phone: (602) 372-0291
www.maricopa.gov/planning
Email address:
Larry.morden@maricopa.gov
Planning & Development
Engineering Plan Review
Date:
May 1, 2025
Memo To: Darren Gerard, AICP, Planning Manager, Department of Planning &
Development
Attn:
Joel Landis, Planner, Planning & Development Services
From:
Larry Morden, P.E., Engineering Supervisor, Planning & Development
Services
cc:
Bob Fedorka, P.E., Engineering Manager, Planning & Development
Subject:
Z250001 - Zone Change (From RU-43 to IND-2 IUPD) for Harquahala
Flatts BESS (E2 Memo)
Job Site Address: I-10 and 443rd Avenue
APN(s):
506-31-015
PND Engineering Plan Review (DPR, FCD and PND Transportation) has reviewed the
2nd submittal of the Zone Change application and has no objections subject to the
following conditions:
1. Without the submittal of a precise plan of development, no development approval
is inferred by this review, including, but not limited to number of proposed building
lots/units, drainage design, access and roadway alignments. These items will be
addressed as development plans progress and are submitted to the County for
further review and/or entitlement.
2. Development in regulated floodplains must comply with the Floodplain
Regulations for Maricopa County.
3. A traffic impact study must be submitted with future entitlement application(s).
4. Private utilities that will occupy County R/W require a license in addition to any
construction related permits. Contact MCDOTsolarlicense@maricopa.gov. See
https://www.maricopa.gov/DocumentCenter/View/74250/MCDOT-Solar-
License-Application for more information.
5. Engineering review of re-zone cases is conceptual in nature. All development and
engineering design shall be in conformance with Section 1205 of the Maricopa
County Zoning Ordinance; Drainage Policies and Standards; Floodplain
Regulations for Maricopa County; MCDOT Roadway Design Manual; and current
engineering policies, standards and best practices at the time of application for
construction.
Please contact me if you have any questions or require any additional information.
Harquahala Flats BESS
Traffic Statement
APRIL 2025
Prepared By:
Traffic Impact Study - Approved
As per Attached Comments
05/28/2025 3:22:48 PM
MCDOT Traffic Engineering
2
Harquahala Flats BESS │ Final Traffic Statement
April 2025 │ Ver. 2
Contents
1
Introduction ....................................................................................................................... 3
Development Description .................................................................................................... 3
Street Network Characteristics ........................................................................................... 5
Existing Traffic Volumes ..................................................................................................... 5
2
Project Characteristics ...................................................................................................... 6
Daily Operations Trip Generation ....................................................................................... 6
TRIP DISTRIBUTION ...................................................................................................... 6
AUXILARY LANES ........................................................................................................... 6
3
Heavy Vehicle Construction Traffic ................................................................................... 7
4
Conclusions and Recommendations ................................................................................. 8
Figures
Figure 1-1 Regional Vicinity Map ................................................................................................. 4
Figure 1-2 Anticipated Site Driveway Locations .......................................................................... 4
Appendices
Appendix A
Preliminary Site Plan
Appendix B
Development Plan
3
Harquahala Flats BESS │ Final Traffic Statement
April 2025 │ Ver. 2
1 INTRODUCTION
The following Traffic Statement (TS) has been prepared to identify the potential traffic effects associated
with the operations of the Harquahala Flats BESS development (Project).
DEVELOPMENT DESCRIPTION
The Project consists of 32.8 acres of agricultural land on the western end of Maricopa County. It is located
south of Interstate 10 (I-10), approximately 23 miles west of the State Route 85 (SR 85) connection to I-10,
and one mile north of Indian School Road. Figure 1-1 depicts the Project location with a regional context.
The site is located entirely on private land and covers a portion of one parcel: 506-31-015. The parcel is
321 acres as a whole, but the portion north of I-10 will not be developed as part of the Project.
The proposed site plan includes an approximately 450 megawatt, battery energy storage system (BESS).
Appendix A contains the preliminary site plan. Appendix B contains the preliminary development plan.
Access to the site will be established by the two full-access driveways shown in Figure 1-2.
•
Driveway A located on 443rd Avenue just south of I-10, and one mile north of Indian School Road
o
Driveway A will serve as the main entrance to the site
•
Driveway B located on 443rd Avenue approximately 0.2 miles south of Driveway A, and
approximately 0.8 miles north of Indian School Road
o
Driveway B will serve as a secondary emergency access to the site
Maricopa County Department of Transportation (MCDOT) requires that driveways be spaced a minimum
of 250 feet from adjacent intersections on major collector roadways. As currently planned, all driveways will
be located at least 250 feet from major or collector intersections. For purposes of this TS, it is anticipated
that the facility will be constructed by the end of 2026.
4
Harquahala Flats BESS │ Traffic Statement
April 2025 │ Ver. 2
Figure 1-1 Regional Vicinity Map
Figure 1-2 Anticipated Site Driveway Locations
5
Harquahala Flats BESS │ Traffic Statement
April 2025 │ Ver. 2
STREET NETWORK CHARACTERISTICS
The proposed site will be accessed regionally from I-10. Local access to the site will be provided by, 443rd
Avenue, Indian School Road, and 411th Avenue. Updated future functional classifications were received by
MCDOT for many of these roadways. Indian School Road is the only MCDOT roadway that is located in
the vicinity of the Project site.
Interstate 10 is located less than 200 feet north of the proposed Project site and is generally aligned east-
west. Near to the site, I-10 is a four-lane divided freeway with a 150-foot dirt median with paved shoulders
inside and outside the travel lanes in each direction. The posted speed limit is 75 mph in the vicinity of the
site. Even with close proximity to I-10, the nearest regional access point to the site is at the interchange
with 411th Avenue, which is located approximately four miles to the east of the Project site.
Indian School Road has a functional classification of major collector by MCDOT and minor collector by
ADOT and is an east-west aligned roadway with one lane in each direction and is currently unpaved.
443rd Avenue is a north-south aligned roadway with one lane in each direction that provides local access
to the site. It is currently unpaved and is not a classified roadway by either ADOT or MCDOT.
The 443rd Avenue/Indian School Road intersection is currently stop-controlled with stop signs on 443rd
Avenue.
411th Avenue is a paved, north-south aligned roadway with one lane in each direction that provides regional
access to the Community of Tonopah, and the site. It is a MCDOT roadway classified as minor arterial
south of I-10 and has a traffic interchange with I-10.
EXISTING TRAFFIC VOLUMES
Daily traffic volumes for roadways in the vicinity of the site were obtained using the ADOT Transportation
Data Management System (TDMS) database. 2023 traffic volumes on Indian School Road are summarized
in Table 1-1.
Table 1–1 Existing Daily Traffic Volumes
Location ID
Count Location
2023 AADT
MMA-3350
Indian School Road, west of 411th Avenue
1,288 vpd
MMA-4717
Indian School Road, east of Salome Highway
5 vpd
MMA-3351
411th Avenue, between I-10 and Indian School Road
511 vpd
6
Harquahala Flats BESS │ Traffic Statement
April 2025 │ Ver. 2
2 PROJECT CHARACTERISTICS
The following section describes anticipated traffic characteristics of the proposed project site.
DAILY OPERATIONS TRIP GENERATION
Institute of Transportation Engineers (ITE) Trip Generation 11th Edition does not contain land use
information for BESS sites such as this one. Trip generation estimates were developed for the site based
on information provided by the project applicant.
The BESS facility will generally be unmanned during typical operations. However, it is anticipated that
workers will access the site periodically for regular maintenance and related activities. For purposes of this
TS, it is anticipated that the site would generate up to 2 visits to and from the site during a typical day. It is
assumed that one of these visits would occur in the AM peak hour and the other in the PM peak hour.
As previously described, the site only has one main entrance or access drive (Driveway A) that will typically
be used to access the site. There is also a second emergency access driveway (Driveway B). This analysis
only considers trips utilizing Driveway A. A single visit would result in 1 trip in and 1 trip out at Driveway A.
The worst-case scenario would be 1 trip in and 1 trip out at Driveway A for each visit, or 4 total daily trips
(2 occurring in the AM peak hour and 2 occurring in the PM peak hour). It is anticipated that of these trips
to and from the facility will be completed in a pickup truck. A trip generation summary for the worst-case
scenario is provided in Table 2-1.
Table 2–1 Worst-Case Project and Driveway Trip Generation
Trip Destination
Daily
Trips
AM Trips
PM Trips
Inbound
Outbound
Inbound
Outbound
Driveway A Trips
4
1
1
1
1
Total Driveway Trips
4
1
1
1
1
TRIP DISTRIBUTION
Based on the existing roadway network, it is assumed that the Project traffic will come to/from I-10 utilizing
411th Avenue, Indian School Road, and 443rd Avenue. Primary site access is expected to be provided by
443rd Avenue.
AUXILARY LANES
The MCDOT Roadway Design Manual provides criteria for when left and right turn auxiliary lanes are to be
provided at site access driveways.
MCDOT requires the installation of a right turn lane at a project access drive when either of the following is
met:
7
Harquahala Flats BESS │ Traffic Statement
April 2025 │ Ver. 2
•
The outside lane has an expected volume of 250 vph or greater and the right turn volume is greater
than 55 vph.
•
Any three of the below criteria are met:
a. At least 5,000 vehicle per day are using or are expected to be using the adjacent street.
b. The roadway’s posted speed limit is greater than 35 mph.
c. At least 1,000 vehicles per day are using or are expected to use the driveway.
d. At least 30 vehicles are expected to make right-turns into the driveway within a one-hour period.
Based on the existing traffic volumes and the anticipated worst-case site traffic, right turn lanes are not
warranted at either of the proposed access driveways.
The MCDOT requirements for installation of a left turn lane are shown in Figure 2-1.
Source: MCDOT Roadway Design Manual
Figure 2-1 MCDOT Left Turn Volume Warrant Criteria
The minimum required peak hour volume of left turning vehicles to warrant a left turn lane on a one-lane
roadway is 8 vph. It is not anticipated that the site will have more than 4 total daily trips (2 inbound / 2
outbound), which would only occur at Driveway A. As such, left turn lanes are not warranted at either of the
proposed access driveways.
3 HEAVY VEHICLE CONSTRUCTION TRAFFIC
Based on similar BESS facility construction trip generation estimates, it is expected that the project site will
generate approximately 2 heavy vehicle trips during each of the AM and PM peak hours (1 trips in and 1
trips out) for a total of 4 daily trips (2 trips in and 2 trips out). It is expected that these trips will be primarily
for deliveries.
There are two classified roadways in the vicinity of the site that would experience construction traffic: Indian
School Road as a major collector, and 411th Avenue as a minor arterial. Table 2.1 of the MCDOT Roadway
Design Manual lists the maximum average daily traffic (ADT) volume for various classifications and
configurations.
Indian School Road, which is a rural, two-lane, undivided major collector, has a maximum ADT of 8,800
vehicles per day (vpd). Table 1-1 of this TS shows the highest recorded existing daily volume on Indian
School Road in the project vicinity is 1,288. The addition of construction traffic, particularly heavy vehicle
8
Harquahala Flats BESS │ Traffic Statement
April 2025 │ Ver. 2
traffic, should more than accommodate this traffic with the remaining 8,792 vpd road capacity. 411th
Avenue, which is a rural, two-lane, undivided minor arterial, has a maximum ADT of 9,500 vpd. Table 1-1
of this TS shows the highest recorded existing daily volume on 411th Avenue in the project vicinity is 511
vpd. The addition of construction traffic, particularly heavy vehicle traffic, should more than accommodate
this traffic with the remaining 9,492 vpd road capacity.
Based on the capacity and heavy vehicle results, it is not anticipated that the surrounding roadways will
require mitigations to accommodate heavy vehicle site traffic during construction even if the number of daily
heavy vehicle deliveries is increased.
4 CONCLUSIONS AND RECOMMENDATIONS
The Project is expected to generate a maximum of 2 daily visits to the site or 4 daily trips at Driveway A.
This worst-case scenario would occur when maintenance activities are periodically required on the site and
would not be a daily occurrence, as the facility is generally unmanned. Based on the current roadway
network conditions, existing traffic, and minimal traffic generated by the Project, all streets within the study
area are anticipated to facilitate access to the site without traffic operations deficiencies. Additionally, based
on MCDOT standards, auxiliary turning lanes are not required at the Project access driveways.
During construction, the site is expected to generate approximately 2 heavy vehicle trips during each of the
AM and PM peak hours (1 trip in and 1 trip out) for a total of 4 daily trips (2 trips in and 2 trips out). It is
expected that these trips will be primarily for deliveries. Additional construction traffic is expected to be
accommodated by the surplus capacity available on the surrounding roadway network. Based on these
capacity and heavy vehicle results, it is not anticipated that the surrounding roadways will require
mitigations to accommodate heavy vehicle site traffic during construction even if the number of daily heavy
vehicle trips is higher than what is reported in this TS.
Harquahala Flats BESS │ Traffic Statement
April 2025 | Ver 2
APPENDIX A: PRELIMINARY SITE PLAN
Harquahala Flats BESS │ Traffic Statement
April 2025 | Ver 2
APPENDIX B: DEVELOPMENT PLAN