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February 25, 2026 Z250031 Page 1 of 3 Report to the Board of Supervisors Prepared by the Maricopa County Planning and Development Department Board Hearing Date: February 25, 2026 Case #/Title: Z250031 – Sun Basin VII Supervisor District: 4 Applicant/Owner: Alyssa Menzel, Sun Basin Solar, LLC Request: Zone Change with Overlay from Rural-190 to IND-2 IUPD Site Location: Generally located Approx 5,881 ft. southwest of the southwest corner of Elliott Rd. & 363rd Ave. in the Arlington area Site Size: Approximately 65 acres County Island Status: N/A Additional Comments: The zone change request is to allow for a battery energy storage system (BESS) to complement many power generation uses in the immediate area. At the Commission hearing, staff with applicant concurrence introduced an additional condition ‘c.10’ that loading /unloading zones would not be required for BESS use. There are no outstanding concerns from reviewing agencies. There is no known opposition. February 25, 2026 Z250031 Page 2 of 3 Commission Recommendation: On 1/22/26, the Commission voted 6-0 (motion by Commissioner Rochwalik, D3, seconded by Commissioner Lindblom, D1) to adopt a motion recommending the Board of Supervisors approve Z250031 subject to conditions ‘a’ - ‘g’: a. A Plan of Development is approved subject to site plan entitled “Sun Basin VII Solar Project Site Plan” consisting of 8 full-size sheets, dated November 12, 2025. The Plan of Development may be amended administratively under separate application as long as the amendment complies with the established IUPD development standards as approved by the Board of Supervisors. 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 “Sun Basin VII Project”, consisting of 17 pages, dated November 2025, except as modified by the following conditions. c. The following IND-2 IUPD standards shall apply: 1. Minimum Front Yard – 100’ 2. Minimum Side Yard -100’ 3. Minimum Rear Yard – 100’ 4. Minimum Parking: No Parking required 5. Minimum Screening: Minimum 6’ tall chain-link fences adjacent to rural/residential zoning boundaries, including attached barbed wire or concertina wire under 8’ in height, and allow all gates to have no attached screening. No screen wall, berm or hedges required along front property lines. 6. Minimum Paving: Alternative surfacing materials or methods approved by Maricopa County Air Quality to minimize dust pollution, such as but not limited to, native compacted soil or aggregate base course, may be used in driveways and parking areas. 7. Minimum Landscaping/Buffering: No landscaping or irrigation required. No screening required adjacent to rural and residential zoning districts. 8. Minimum Sight Visibility Triangles: Within sight visibility triangles at any intersection, on-site chain-link fences without screening materials can exceed a height of 2’. 9. The IUPD overlay shall limit entitled uses to power generation and distribution, BESS facilities and ancillary uses. 10. Loading and Unloading: none required. d. The following Planning Engineering conditions shall apply: 1. Engineering review of planning and/or zoning cases is for conceptual design only. 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. 2. Based on the conceptual design nature of the information submitted, changes to the site layout may be necessitated by the final engineering design of the drainage infrastructure. February 25, 2026 Z250031 Page 3 of 3 3. Detailed Grading and Drainage (Infrastructure) Plans must be submitted with the application for Building Permits. e. Prior to issuance of the initial building permit, all parcels shall be combined to create a single parcel matching the zone change area. f. Prior to issuance of a building permit, written confirmation will be required from the emergency fire protection jurisdiction having authority that the facility has been designed in accordance with their regulations and requirements, and that emergency fire protection service will be provided to the facility. Prior to issuance of the certificate of occupancy, local fire protection jurisdiction review and approval will be required. g. 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 by the Board after recommendation by the Commission at a public hearing for reversion to the zoning that existed on the date of application. It is, therefore, stipulated and agreed that either revocation 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 revocation of the Zone Change. The 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: Reviewed by: Attachment: Andrew Lorentzen, Planner Darren Gérard, AICP, Planning Manager 1/22/26 P&Z Packet (38 pages) 1/22/26 Handout Memo (2 pages) Note: 1/22/26 Draft P&Z Minutes are not available as of the writing of this report, but can be provided upon request later when available. Z250031 Page 1 of 9 Report to the Planning and Zoning Commission Prepared by the Maricopa County Planning and Development Department Case: Z250031 – Sun Basin VII Hearing Date: January 22, 2026 Supervisor District: 4 Applicant/ Owner Alyssa Menzel, Sun Basin Solar, LLC Request: Zone Change with Overlay from Rural-190 to IND-2 IUPD Site Location: Generally located Approx 5,881 ft. southwest of the southwest corner of Elliott Rd. & 363rd Ave. in the Arlington area Site Size: Approximately 65 acres Density: N/A County Island: No County Plan: Old US Hwy 80 Area Plan –Industrial / Utilities Municipal Plan: N/A Municipal Comments: None received to date Support/Opposition: None known Recommendation: Approve with conditions Z250031 Page 2 of 9 Project Summary: 1. The application intends to rezone 32 properties from Rural-190 to IND-2 IUPD with a Plan of Development (POD) for battery energy storage system (BESS). This project is part 7 of a multi- site regional energy project known as The Sun Basin Project. The BESS facility will include approximately 65 acres of development with 15 of those acres being directly reserved for power transfer substation use. 2. The project will be comprised of battery storage pods with a single operational building proposed. The operational goal is to create a 800-MW storage system at this single location. The site has been engineered for drainage requirements with provided onsite retention throughout. It is directly adjacent to other power generation facilities including additional BESS facilities to the east and is in the direct vicinity of the Palo Verde Nuclear Generating Station. 3. The site is located in the Old US Hwy 80 area plan which has a designation of Industrial / Utilities. It has been designated as Industrial / Utilities with the original dedication of the plan in 2007 and has not been part of a land use designation change. 4. The applicant is requesting to amend specific development standards to ease construction related issues, adapt for industry standards and to address additional safety and security standards. Alternative parking, loading, SVT and paving standards, as referenced in the table below, demonstrate a reduced presence on the site as compared to traditional industrial uses. The applicant is requesting to amend the screening standards from a required CMU wall to a 6’ chain-link fence with 2’ barbed wire. The site has been designed with 100’ setbacks and will be codified in the IUPD to protect any future adjacent parcels or users. REGULATION BASE ZONING DISTRICT REGULATIONS (IND-2) PROPOSED ZONING DISTRICT REGULATIONS (IND-2 IUPD) Maximum Height 60’ 60’ Minimum Front Yard 10’-25’ 100’ Minimum Side Yard 3’-10' 100’ Minimum Street-side Yard 10' 100 Minimum Rear Yard 0’-25' 100’ Minimum Lot Area 6,000 sq. ft. 6,000 sq. ft. Minimum Lot Width * 60' 60’ Maximum Lot Coverage 60% 60% Minimum Parking Spaces See parking regulations No required parking Minimum Screening Minimum 6’ concrete masonry unit wall adjacent to rural and residential zoning boundaries and for outdoor use of an industrial nature. The front property line shall be screened with a 3’ screen wall, berm or hedge to minimize headlight glare. Minimum 6’ tall chain-link fences adjacent to rural/residential zoning boundaries, including attached barbed wire or concertina wire under 8’ in height, and allow all gates to have no attached screening. No screen wall, berm or hedges required along front property lines. Z250031 Page 3 of 9 Minimum Paving Article 1102.7.1. For other than one single-family dwelling unit or one mobile home on a lot of record, any parking area must be paved or in the alternative surfaced with aggregate base course material. Alternative surfacing materials or methods approved by Maricopa County Air Quality to minimize dust pollution, such as but not limited to, native compacted soil or aggregate base course, may be used in driveways and parking areas. Minimum Landscaping/Buffering There shall be a solid fence, wall and suitable planting six feet in height where the side or rear lot lines or boundaries of the lot are adjacent to a rural or residential zoning district. All street frontage of the lot shall be landscaped with drought-tolerant plants including trees, shrubs or natural vegetation. There shall be a minimum of one tree and three shrubs every 20 feet. Trees shall be a minimum 2-inch caliper at the time of installation. The required side yards shall be landscaped with drought- tolerant plants including trees, shrubs or natural vegetation. 4% of the gross parking area shall be landscaped with trees, shrubs, or natural vegetation. Any part of the lot not used for buildings, other structures, parking and vehicular and pedestrian access shall be landscaped with grass, trees, shrubs, xeriscaping or natural vegetation. All landscaped areas shall be provided with water bibs or an automatic sprinkler No landscaping or irrigation required. No screening required adjacent to rural and residential zoning districts. Minimum Sight Visibility Triangles (SVTs) No obstructions over 2’ in height within 25’ x 25’ SVTs. Within sight visibility triangles at any intersection, on-site chain-link fences without screening materials can exceed a height of 2’. Z250031 Page 4 of 9 2025 Aerial-photo Aerial image & surrounding environs Z250031 Page 5 of 9 Eagle view of subject site looking north into subject parcel (aerial image dated September 30, 2021) Site Plan Z250031 Page 6 of 9 5. It should be noted that since the applicant is proposing a site plan (required plan of development, POD) and although the zone change is a legislative approval, the POD is administratively approved. Therefore, POD approval is contingent upon prior rezoning approval. Existing On-Site and Adjacent Zoning / Land Use: 6. On-site: Rural-190 / Vacant Undeveloped North: Rural-190 / Undeveloped – Power transfer substation South: IND-2 IUPD / Redhawk Power Generation Facility - Solar Power Generation East: IND-2 IUPD / Redhawk Power Generation Facility - BESS unit West: Rural-190 / Undeveloped – Power transfer substation Current Zoning Z250031 Page 7 of 9 Proposed Zoning Utilities and Services: 7. Water: Well Wastewater: Septic Fire: Arizona Fire and Medical Authority Police: Maricopa County Sherriff Right-of-Way: 8. 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 Elliot Rd. 28’ 28’ Minor Arterial Adopted Plan: 9. Old US Hwy 80 Area Plan (adopted May 2007): Industrial / Utilities – Industrial is listed under the plan as an appropriate designation for “warehousing, storage, distribution activities, and general manufacturing. Compatibility with adjacent current and future land use is an important consideration”. Industrial zoning for power generation and associated uses is consistent with the plan. Public Participation Summary: Z250031 Page 8 of 9 10. The applicant has notified local landowners of the proposed zone change utilizing signs being posted onsite and along the adjacent ROW along Elliot Rd. Letters of intent were sent out to all local landowners within 300’ of the subject parcel. Staff has not received any public or municipal comments to the application. The applicant has met all notification requirements set forth by county staff. Outstanding Concerns from Reviewing Agencies: 11. N/A Staff Analysis: 12. Staff supports the further development of the Sun Basin project and Sun Basin VII BESS proposal. The BESS facility will add to the regional power infrastructure and regional energy availability. The site is ideally located next to established power infrastructure sites, existing industrial uses and is not located near established residential uses. Staff does note that there are five adjacent vacant parcels that are not part of the BESS facility. While a future BESS facility may affect future residential development uses, staff notes that only one of these parcels currently meets minimum 190,000 square feet minimum lot area requirement of the Rural-190 zoning district. Recommendation: 13. Staff recommends the Commission adopt a motion recommending that the Board of Supervisors approve Z250031 subject to the following conditions ‘a’ – ‘g’: a. A Plan of Development is approved subject to site plan entitled “Sun Basin VII Solar Project Site Plan” consisting of 8 full-size sheets, dated November 12, 2025. The Plan of Development may be amended administratively under separate application as long as the amendment complies with the established IUPD development standards as approved by the Board of Supervisors. 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 “Sun Basin VII Project”, consisting of 17 pages, dated November 2025, except as modified by the following conditions. c. The following IND-2 IUPD standards shall apply: 1. Minimum Front Yard – 100’ 2. Minimum Side Yard -100’ 3. Minimum Rear Yard – 100’ 4. Minimum Parking: No Parking required 5. Minimum Screening: Minimum 6’ tall chain-link fences adjacent to rural/residential zoning boundaries, including attached barbed wire or concertina wire under 8’ in height, and allow all gates to have no attached screening. No screen wall, berm or hedges required along front property lines. 6. Minimum Paving: Alternative surfacing materials or methods approved by Maricopa County Air Quality to minimize dust pollution, such as but not limited to, native compacted soil or aggregate base course, may be used in driveways and parking areas. Z250031 Page 9 of 9 7. Minimum Landscaping/Buffering: No landscaping or irrigation required. No screening required adjacent to rural and residential zoning districts. 8. Minimum Sight Visibility Triangles: Within sight visibility triangles at any intersection, on-site chain-link fences without screening materials can exceed a height of 2’. 9. The IUPD overlay shall limit entitled uses to power generation and distribution, BESS facilities and ancillary uses. d. The following Planning Engineering conditions shall apply: 1. Engineering review of planning and/or zoning cases is for conceptual design only. 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. 2. Based on the conceptual design nature of the information submitted, changes to the site layout may be necessitated by the final engineering design of the drainage infrastructure. 3. Detailed Grading and Drainage (Infrastructure) Plans must be submitted with the application for Building Permits. e. Prior to issuance of the initial building permit, all parcels shall be combined to create a single parcel matching the zone change area. f. Prior to issuance of a building permit, written confirmation will be required from the emergency fire protection jurisdiction having authority that the facility has been designed in accordance with their regulations and requirements, and that emergency fire protection service will be provided to the facility. Prior to issuance of the certificate of occupancy, local fire protection jurisdiction review and approval will be required. g. 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 by the Board after recommendation by the Commission at a public hearing for reversion to the zoning that existed on the date of application. It is, therefore, stipulated and agreed that either revocation 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 revocation of the Zone Change. The 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: Andrew Lorentzen, Planner Reviewed by: Rachel Applegate, Planning Supervisor Attachments: Case Map (1 page) Site Plan (8 pages) Narrative Report (17 pages) Engineering Comments (2 pages) MCESD comments (1 page) / Maricopa County Planning & Development - Phoenix, AZ 4 Gross Acres: 65 approx. Generated January 6, 2026 4:40 PM Z250031 Application Name: Legal Description Sun Basin VII Project Applicant Case Address Courtney Van Winkle 37157 W CARVER RD Applicant Phone/Email Parcel Primary:401-43-034G (760) 685-0269 ARLINGTON, AZ 85322 Map scale 1:6,538 Supervisor District No. Sun Basin VII Project - Zone Change with Overlay for Solar. Sun Basin VII Project is a battery energy storage system (BESS) project with ancillary facilities to support solar energy generation. In April of this P: 602.490.0535 / F: 602.368.2436 www.hilgartwilson.com 4742 N 24th Street, Suite 270 PHOENIX, AZ 85016 HAS JOINED COLLIERS ENGINEERING & DESIGN 15 Regulation Base IND-2 Zoning District Standards Proposed IND-2 IUPD Zoning District Standards Height 60’ 60’ Front Yard 10’-15’**- 20’***-25’*. 100’ Side Yard 3’-10’* 100’ Rear Yard 0’-25’* 100’ Parking Article 1102.1.4: 1 space per 250 sq. ft. of floor area (Office) No required parking. Loading and Unloading Article 1103.2 one loading and unloading space for each 10,000 square feet of floor area, or fraction thereof, devoted to such use in the building. None. Sight Visibility Triangles (SVTs)No obstructions over 2’ in height within 25’ x 25’ SVTs. Within sight visibility triangles at any intersection, on-site chain-link fences without screening materials can exceed a height of 2’. Paving Article 1102.7.1. For other than one single-family dwelling unit or one mobile home on a lot of record, any parking area must be paved or in the alternative surfaced with aggregate base course material. Alternative surfacing materials or methods approved by Maricopa County Air Quality to minimize dust pollution, such as but not limited to, native compacted soil or aggregate base course, may be used in driveways and parking areas. Site Enclosure and Screening Minimum 6’ concrete masonry unit wall adjacent to rural and residential zoning boundaries and for outdoor use of an industrial nature. The front property line shall be screened with a 3’ screen wall, berm or hedge to minimize headlight glare. Minimum 6’ tall chain-link fences adjacent to rural/residential zoning boundaries, including attached barbed wire or concertina wire under 8’ in height, and allow all gates to have no attached screening. No screen wall, berm or hedges required along front property line. Landscaping/Buffering There shall be a solid fence, wall and suitable planting six feet in height where the side or rear lot lines or boundaries of the lot are adjacent to a rural or residential zoning district. All street frontage of the lot shall be landscaped with drought-tolerant plants including trees, shrubs or natural vegetation. There shall be a minimum of one tree and three shrubs every 20 feet. Trees shall be a minimum 2-inch caliper at the time of installation. The required side yards shall be landscaped with drought-tolerant plants including trees, shrubs or natural vegetation. 4% of the gross parking area shall be landscaped with trees, shrubs, or natural vegetation. Any part of the lot not used for buildings, other structures, parking and vehicular and pedestrian access shall be landscaped with grass, trees, shrubs, xeriscaping or natural vegetation. All landscaped areas shall be provided with water bibs or an automatic sprinkler system. No landscaping or irrigation required. No screening required adjacent to rural and residential zoning districts. Residential Unit Separation n/a Minimum 500’ separation from BESS unit to any existing residential unit. * Adjacent to Rural/Residential zoned properties ** Along Collector/Mid-Section Line roadways ***Along Arterials/Section Line roadways Contact Arizona 811 at least two full working days before you begin excavation CALL 811 or click Arizona811.COM Contact Arizona 811 at least two full working days before you begin excavation CALL 811 or click Arizona811.COM Contact Arizona 811 at least two full working days before you begin excavation CALL 811 or click Arizona811.COM Contact Arizona 811 at least two full working days before you begin excavation CALL 811 or click Arizona811.COM SUN BASIN SOLAR PROJECT Contact Arizona 811 at least two full working days before you begin excavation CALL 811 or click Arizona811.COM The MaxWell TM Plus Drainage System Detail And Specifications Manufactured and Installed by TORRENT RESOURCES An evolution of McGuckin Drilling www.torrentresources.com ARIZONA 602/268-0785 NEVADA 702/366-1234 CALIFORNIA 661/947-9836 AZ Lic. ROC070465 A, ROC047067 B-4, ADWR 363 CA Lic. 528080, C-42, HAZ. NV Lic. 0035350 A - NM Lic. 90504 GF04 U.S. Patent No. 4,923,330 - TM Trademark 1974, 1990, 2004 The MaxWell TM IV Drainage System Detail And Specifications Manufactured and Installed by TORRENT RESOURCES An evolution of McGuckin Drilling www.torrentresources.com ARIZONA 602/268-0785 NEVADA 702/366-1234 CALIFORNIA 661/947-9836 AZ Lic. ROC070465 A, ROC047067 B-4, ADWR 363 CA Lic. 528080, C-42, HAZ. NV Lic. 0035350 A - NM Lic. 90504 GF04 U.S. Patent No. 4,923,330 - TM Trademark 1974, 1990, 2004 Contact Arizona 811 at least two full working days before you begin excavation CALL 811 or click Arizona811.COM Contact Arizona 811 at least two full working days before you begin excavation CALL 811 or click Arizona811.COM Sun Basin VII Project IND-2 (Industrial) Zone Change and Industrial Unit Plan of Development (IND-2 IUPD) Narrative Report SE of Elliot Road and Dobbins Road in the Arlington Area Z250031 Submitted to: Maricopa County Planning and Development Department November 2025 TABLE OF CONTENTS 1.0 Introduction ................................................................................................................................................... 3 1.1 Project Name .................................................................................................................................................... 3 1.2 Applicant ........................................................................................................................................................... 3 2.0 Purpose of Request ....................................................................................................................................... 3 2.1 Industrial Unit Plan of Development ................................................................................................................ 4 2.1.1 Justifications for Proposed Zoning District Standards ....................................................................................... 6 3.0 Description of Proposal ................................................................................................................................. 7 3.1 Overview ........................................................................................................................................................... 7 3.2 Battery Energy Storage System ........................................................................................................................ 8 3.3 Interconnection Facilities ................................................................................................................................... 8 3.4 Landscaping ...................................................................................................................................................... 9 3.5 Operation and Maintenance ............................................................................................................................ 9 3.5.1 Site Security and Lighting ............................................................................................................................. 9 3.5.2 Weed Management .................................................................................................................................... 10 4.0 Relationship to Surrounding Properties ...................................................................................................... 10 5.0 Location and Accessibility............................................................................................................................ 11 6.0 Circulation System ....................................................................................................................................... 12 7.0 Development Schedule ............................................................................................................................... 13 7.1 Phasing Schedule ............................................................................................................................................ 13 8.0 Community Facilities and Services ............................................................................................................... 13 8.1 Emergency Response Plan ............................................................................................................................. 13 9.0 Public Utilities and Services ......................................................................................................................... 14 9.1 Fire Protection ................................................................................................................................................ 14 9.2 Police Protection ............................................................................................................................................ 14 9.3 Water and Wastewater Resources................................................................................................................. 14 9.4 Electric ............................................................................................................................................................ 15 10.0 Drainage and Grading .................................................................................................................................. 15 10.1 Drainage Design ............................................................................................................................................. 15 10.2 Grading Design ................................................................................................................................................ 15 11.0 Environmental Impacts ................................................................................................................................ 16 11.1 Noise ............................................................................................................................................................... 16 11.2 Air Quality ...................................................................................................................................................... 16 11.3 Visual Resources ............................................................................................................................................. 16 11.4 Biological Resources ....................................................................................................................................... 16 3 1.0 Introduction 1.1 Project Name The name of the project is the Sun Basin VII Project, hereafter referred to as Sun Basin VII or the Project in this narrative report. 1.2 Applicant The Applicant is Sun Basin Solar, LLC, a wholly owned subsidiary of Longroad Energy Holdings, LLC (Longroad). Longroad is a U.S.-based developer, owner, and operator of renewable energy projects and is led by a team of industry veterans with a demonstrated track record of success on numerous projects in Arizona. In 2021, Longroad successfully completed construction and started commercial operations of the 150-megawatt (MW) Sun Streams 2 Solar Project in Maricopa County. In 2024, Longroad began commercial operations on the 215-MW solar and storage Sun Streams 3 Project. This was followed by the 300-MW solar and storage Sun Streams 4 Project which began commercial operations in 2025. Longroad has a fifth Arizona solar project currently under construction in Maricopa County, and earlier in 2025, completed the permitting for Sun Basin 1-6 which, along with Sun Basin 7, complete the Sun Basin Solar and Storage project. Longroad has a development pipeline in excess of 5,500 MW and, through a subsidiary, is contracted to operate and manage a wind and solar operating portfolio of over 6,000 MW. During its time together, the Longroad team has successfully developed over 20 utility-scale wind and solar projects. Longroad is owned and funded by the New Zealand Superannuation Fund (“NZSF”), Infratil Limited, Longroad’s Management Team, and MUNICH ERGO Asset Management, and currently has over $35 billion in assets under management. 2.0 Purpose of Request The Project is located in unincorporated, western Maricopa County in the vicinity of the Palo Verde Nuclear Generating Station (PVNGS). The Project is located in the more immediate vicinity of the Mesquite Generating Station, Hassayampa Switchyard, Chukar Substation, and Red Hawk Generating Station. The Project site is located on approximately 65 acres of private land south of Elliot Road, east of Dobbins Road, north of Narramore Road (alignment), approximately 3.5 miles west of the community of Arlington. This site is near significant existing power generation projects and energy infrastructure in the vicinity of the PVNGS, including several approved and existing solar projects. The Applicant requests to rezone approximately 65 acres of private land from Rural (RU-190) to Industrial (IND-2), with an Industrial Unit Plan of Development (IUPD), to allow the development of an 800-MW battery energy storage system (BESS) and ancillary facilities to support photovoltaic (PV) solar energy generation. The current Comprehensive Plan land use designation for the Project site is Industrial under the Old US Highway 80 Area Plan, which is compatible with the rezone application and the planned use for the site. 4 The Project will consist of a BESS, electrical collection systems (including project substation), operations and maintenance (O&M) building, water tank, storage warehouse, and other ancillary facilities. The battery energy storage facilities will provide storage of electricity generated by the previously approved projects Sun Basin 1 through 6. The Applicant’s plan for timing of the Project is to construct immediately once the requisite permits and approvals have been received from Maricopa County. This rezoning application is the first step in preparing this Project site for development. Once the permits and approvals have been received, it is anticipated that the Project will take approximately 18-24 months to construct. It is anticipated that the Project could start construction as soon as 2026 and the commercial operation date (COD) would be in 2028 or later. The Applicant will develop this Project in response to market demand. 2.1 Industrial Unit Plan of Development To develop the Project as planned, the Applicant will be seeking modifications from County development standards using the overlay zoning district IUPD mechanism. According to the Maricopa County Zoning Ordinance, the purpose of the IUPD is to allow variations to development standards for industrial projects that require special design techniques or flexibility due to topography, innovative or sustainable project design, or other considerations. The majority of these modifications are related to the remote nature of this site. As a result, the Applicant is seeking to confirm that none of the mile or half-mile street alignments will be developed through the site, and therefore, typical street development standards including setbacks, improved landscaping, fencing and site visibility triangles (SVTs) are not necessary at the site. The specific modifications of County development standards are set forth in Table 1 below with deviations in bold. Justifications for the modifications are discussed in Section 2.1.1. Table 1 – Sun Basin VII Solar Project IUPD Modifications to Development Standards Regulation Base IND-2 Zoning District Standards Proposed IND-2 IUPD Zoning District Standards Height 60’ 60’ Front Yard 10’-15’**- 20’***-25’*. 100’ Side Yard 3’-10’* 100’ Rear Yard 0’-25’* 100’ Parking Article 1102.1.4: 1 space per 250 sq. ft. of floor area (Office) No required parking. Loading and Unloading Article 1103.2 one loading and unloading space for each 10,000 square feet of floor area, or fraction thereof, devoted to such use in the building. None. 5 Sight Visibility Triangles (SVTs) No obstructions over 2’ in height within 25’ x 25’ SVTs. Within sight visibility triangles at any intersection, on-site chain-link fences without screening materials can exceed a height of 2’. Paving Article 1102.7.1. For other than one single-family dwelling unit or one mobile home on a lot of record, any parking area must be paved or in the alternative surfaced with aggregate base course material. Alternative surfacing materials or methods approved by Maricopa County Air Quality to minimize dust pollution, such as but not limited to, native compacted soil or aggregate base course, may be used in driveways and parking areas. Site Enclosure and Screening Minimum 6’ concrete masonry unit wall adjacent to rural and residential zoning boundaries and for outdoor use of an industrial nature. The front property line shall be screened with a 3’ screen wall, berm or hedge to minimize headlight glare. Minimum 6’ tall chain-link fences adjacent to rural/residential zoning boundaries, including attached barbed wire or concertina wire under 8’ in height, and allow all gates to have no attached screening. No screen wall, berm or hedges required along front property line. Landscaping/Buffering There shall be a solid fence, wall and suitable planting six feet in height where the side or rear lot lines or boundaries of the lot are adjacent to a rural or residential zoning district. All street frontage of the lot shall be landscaped with drought-tolerant plants including trees, shrubs or natural vegetation. There shall be a minimum of one tree and three shrubs every 20 feet. Trees shall be a minimum 2-inch caliper at the time of installation. The required side yards shall be landscaped with drought-tolerant plants including trees, shrubs or natural vegetation. 4% of the gross parking area shall be landscaped with trees, shrubs, or natural vegetation. Any part of the lot not used for buildings, other structures, parking and vehicular and pedestrian access shall be landscaped with grass, trees, shrubs, xeriscaping or natural vegetation. All landscaped areas shall be provided with water bibs or an automatic sprinkler No landscaping or irrigation required. No screening required adjacent to rural and residential zoning districts. 6 system. Residential Unit Separation n/a Minimum 500’ separation from BESS unit to any existing residential unit. * Adjacent to Rural/Residential zoned properties ** Along Collector/Mid-Section Line roadways ***Along Arterials/Section Line roadways 2.1.1 Justifications for Proposed Zoning District Standards The following standards for interior lot lines are requested to provide for the transition of uses within the Project area, and in lieu of typical setbacks, a setback of 100 feet is provided. In addition, future right-of-way reservations proposed by the Maricopa County Department of Transportation (MCDOT) will serve as a setback. This perimeter setback and right-of-way reservations will ensure compatibility and sufficient distance from adjacent uses, outside of the Project area. Front Yard The Applicant requests a modification for all front yard setbacks to be 100 feet. The increased setback distance will apply to all structures including BESS which will be a primary use for this project and will be in conformance with the recommendations from the Arizona Fire and Medical Authority (AFMA). Side Yard The Applicant requests a modification for all side yard setbacks to be 100 feet. The increased setback distance will apply to all structures including BESS which will be a primary use for this project and will be in conformance with the recommendations from the AFMA. Rear Yard The Applicant requests a modification for all rear yard setbacks to be 100 feet. The increased setback distance will apply to all structures including BESS which will be a primary use for this project and will be in conformance with the recommendations from the AFMA. Parking Regulations The Applicant requests that no parking spaces be required for this site. No occupied structures are anticipated at the facility, and the Project will require minimal regular vehicle trips once constructed. The Project may include unmanned structures to house components of the BESS. Routine parking of vehicles on-site is not anticipated, and no permanent parking spaces are planned for this site. If parking areas are constructed, alternative surfacing materials may be used as an alternative to paving. Loading and Unloading The Applicant requests that no loading and unloading spaces be required for the site as no occupied structures are anticipated at the facility, no manned Project buildings will be located 7 on-site or on public roads, and there will be no routine deliveries or shipments. Sight Visibility Triangles The Applicant is requesting to allow chain-link fences over two feet in height inside a sight visibility triangle because these types of fences do not obstruct vehicular visibility. Additionally, allowing this will maximize the amount of usable space for BESS structures. Paving The Applicant requests that alternative surfacing materials or methods approved by Maricopa County Air Quality Department, such as but not limited to, native compacted soil or aggregate base coarse, may be used in driveways and parking areas. The adjacent roadways providing access to the Project site are unpaved dirt roads. Unpaved roads on the Project will be maintained to reduce fugitive dust in accordance with County air quality regulations. Site Enclosure and Screening The Applicant requests to install chain-link fencing (at least six feet in height), including concertina or barbed wire topping (up to two feet) above the fence, and gates along the perimeter of the Project. This fencing will not include any screening material such as slats or privacy fabric. The proposed fencing will allow unimpeded surface flows, be consistent with other industrial developments in the area, and provide site security. Screening material will only make the site more visible and should, therefore, be waived as a requirement. The Applicant also proposes to use chain-link for the gates which will be consistent with other adjacent and nearby energy generation projects. Perimeter fencing will include small gaps at the bottom (six to eight inches) to allow for the movement of small wildlife. These gaps will be located in areas where drainage features intersect with the Project perimeter to compensate for large amounts of perimeter fencing on the site. No walls, berms, or hedges will be required for screening for the Project. 3.0 Description of Proposal 3.1 Overview To allow the development of the Project, this zone change application includes the following: • A BESS made up of battery enclosures; • Electrical collection systems, including project substation, PV combining switchgear, power conversion stations, inverters, transformers, collection lines, and emergency generators; • An O&M building; • Associated civil infrastructure including fencing, access driveways and gates, driveways, on-site parking, drainage channels, retention basins, signage, water tanks if required by the Fire District, storage warehouse, and possibly a septic tank and leach field. See the attached set of site plan drawings for details regarding the Project components. 8 3.2 Battery Energy Storage System As solar energy becomes a more important part of the nation's energy supply system, the need to store solar energy for delivery into evening hours has become a growing part of the solar energy production system. The BESS location is anticipated to occupy approximately 20-40 acres of land within the 65-acre Project site. The BESS would be located at least 100’ from the Project boundary and any buildings, and shall be separated a minimum of 500’ from existing residential dwellings. The BESS will be permitted as a primary use within this IUPD. The BESS would be located on the eastern and south western portions of the Project site, and would be adjacent to the project substation and will consist of self-contained battery storage modules placed in racks, switchboards, integrated heating, ventilation, and air conditioning (HVAC) units, inverters, transformers, and controls in prefabricated metal or concrete containers. The enclosures would have appropriate safety systems built to code. The BESS equipment will undergo UL9540A testing to understand the impact of an equipment failure on its surrounding environment. This empirical test data will be utilized to establish adequate equipment setbacks and final design spacing. The BESS may be connected using either an alternating current (AC)-coupled or direct current (DC)-coupled configuration. When an AC-coupled configuration is used, a central BESS system is typically connected to the PV plant at the medium-voltage level. Bidirectional battery inverters convert the power between AC and DC electricity. When charging the batteries, the BESS bidirectional inverters convert the AC electricity to the DC electricity stored by the batteries. When discharging, the bidirectional inverters convert the DC electricity to the AC electricity output by the plant. Transformers are typically used to match the low-level AC voltage at the AC side of the inverters to the medium-level voltage necessary to connect to the substation. 3.3 Interconnection Facilities Once the power is stored, it will need to interconnect into the regional power grid. The Project is located in an area with extensive electrical infrastructure and expects to interconnect into the Hassayampa Switchyard, directly to the north of the Project site. The Project will route electricity via either overhead or underground medium-voltage (34.5 kilovolt [kV]) lines to the Project substation, where the voltage will be stepped up again to match the regional power grid. A short high voltage generation tie (gen-tie) line may be required to connect into the final point of interconnection. The medium-voltage lines will be outside the jurisdiction of the Arizona Corporation Commission (ACC) as they regulate lines of 115 kV or more. Lines of lesser voltage may be constructed up to a height of 120 feet per Maricopa County Zoning Ordinance Article 1111.7. Off-site transmission lines, unless constructed by an Arizona utility holding a Certificate of Convenience and Necessity issued by the ACC, are not exempt from local jurisdiction construction code authority. 9 3.4 Landscaping Where practical, the Project will retain the existing natural desert vegetation along the site perimeter. The Project is remote and, therefore, mostly not visible to passersby on public roads. No irrigation or landscaping will be required along the perimeter of the Project. The BESS components will be spaced a minimum of 100 feet from the property lines along the Project perimeter. The fences will be chain-link topped with barbed wire making them as visually porous as possible. Therefore, any passersby will see natural desert and the BESS facilities. The drainage basins on-site may be partially bermed on their downstream side to a height as much as two feet above existing grade, further screening visual impact. 3.5 Operation and Maintenance When operational, the Project will be remotely monitored and controlled by the Applicant. There will be a small administrative/O&M facility on-site as well as associated equipment storage facilities. There will be up to five full-time employees employed during the operational phase of the Project. These employees will work normal shift hours (generally 8 a.m. to 5 p.m.). Battery energy storage facilities require a limited amount of maintenance. Maintenance activities include, but are not limited to, the following: • Periodic inspections; • Dust control; • Weed control; • Maintaining electrical collection system components (inverters, switchgear, transformers, and BESS); and, • Maintaining on-site infrastructure (driveways, drainage channels, and retention basins), as well as responding to issues detected by remote monitoring of the facility. No major equipment is anticipated to be required for maintenance of the facility except as necessary for periodic equipment replacement. Interior roadways providing access to the Project will not be paved. The majority of interior driveways will be native compacted soil and may require grading. Interior roads will be maintained to reduce fugitive dust. 3.5.1 Site Security and Lighting To provide a secure and safe environment, the Project will be enclosed by an open, chain-link fence topped with barbed wire and all access points will be gated with swinging or rolling chain- link gates topped with barbed wire. The fence and gates will include a minimum of six feet of chain-link topped with up to two feet of barbed wire, for a total of eight feet after the barbed wire. The Applicant plans to use open chain-link fencing to maintain a secure but visually open appearance. Substations will be separately fenced with the same type of fencing. Where 10 necessary, portions of the fencing may increase in height to allow for gaps at the base to enable wildlife movement and drainage. For nighttime security, the Project may use motion-activated lights or infrared (IR) illumination with cameras mounted on 18-foot-tall poles. Because these security lights will be motion- activated or IR illuminated only, the Applicant expects the site to be dark at night. The motion detectors on the security lighting system will not react to animal movement. Furthermore, to ensure that lighting will not be cast onto neighboring properties, all security lighting installed will be directed downward and into the site. All on-site lighting will also comply with Maricopa County Zoning Ordinance Article 1112. Additional security measures that may be implemented include cameras to remotely monitor the site and periodic patrols of the site's perimeter. 3.5.2 Weed Management Following initial mowing of the site, vegetation will be allowed to reestablish to the extent it does not interfere with equipment or facility O&M. The Applicant may need to use weed control to ensure the equipment and retention areas continue to function and to prevent the spread of non-native, invasive plant species. Herbicides will be used as needed on a periodic basis and applied by licensed or certified applicators. Hand removal or mechanical methods (i.e., small drivable weed mowers) of weed control could also be used where necessary and practical. Because weeds can create a fire safety hazard, the presence of weeds (especially tumbleweed) on the site will be regularly monitored and managed throughout the life of the Project. 4.0 Relationship to Surrounding Properties The development of BESS facility at this location is an appropriate and compatible land use with the surrounding area. The area is very rural with minimal nearby population in pockets of single-family low-density land use. The surrounding existing and approved developed uses are primarily industrial, with an emphasis on electrical infrastructure. The predominant land use in the area is energy production and electrical transmission. As previously noted, the PVNGS, the largest nuclear power plant in the United States, as well as several existing gas- fired and solar energy facilities are located nearby. The Project site is surrounded by RU-190 zoned parcels to the north and west, and IND-2 zoned parcels to the east and south. While adjacent RU-190 does allow for residential development at low density among other rural uses, these parcels are currently vacant or are being used for energy infrastructure. The closest RU-43 zoning is located approximately 2 miles to the east of the Project. No current residential use exists within 2 miles of the site. The Hassayampa Switchyard is a major energy transfer facility located approximately 0.2 mile north of the Project site. The Applicant has existing connection agreements into the 11 Hassayampa Switchyard through the existing Applicant-owned Sun Streams complex. Indicative of the appropriateness for the proposed use in this area, several rezonings, Special Use Permits, and Comprehensive Plan Amendment applications have been previously approved by the Maricopa County Board of Supervisors for solar energy generating facilities nearby. These solar energy facilities include Sun Streams I, Sun Streams II, Sun Streams III, Sun Streams IV, Agave Solar, Mesquite Solar, Arlington Valley Solar Energy (AVSE) II and III, Sun Pond I, II, and III, AV Solar Project, and Sun Basin I, II, III, IV, V, and VI. The addition of a battery energy storage facility, like this Project, complements those existing land uses. The proposed Project, when developed, will have a relatively low profile, will be odorless, and will have very little nighttime lighting or activity. Additionally, the BESS would not create discernable off-site noise. Arizona is the natural solar center of the United States. Factors critical to the siting of PV solar energy storage facilities include proximity to energy generating sites (especially solar energy), proximity to existing electrical substations and transmission infrastructure; and compatibility with nearby land uses. Battery energy storage facilities complement solar projects, and their integration can enhance the overall effectiveness and reliability of renewable energy systems. The Project site is located in close proximity to approved and existing solar projects, existing electrical substations and transmission infrastructure, making it a compatible use with nearby land uses. The Project site has immediate access to the Hassayampa Switchyard, limiting the need for extensive off-site overhead transmission facilities to connect to the regional power grid. Solar energy diversifies the energy supply, reduces the country's dependence on foreign oil, improves air quality, offsets greenhouse gas emissions, and helps avoid the construction of additional fossil-fuel-powered plants. In warm climates like Arizona, solar energy is also beneficial for satisfying peak energy demands as solar energy is generated when the demand for electricity is at its peak (during daylight hours). BESS facilities provide reliability benefits to the power grid, as it allows excess solar energy generated during the day to be dispatched at a later time. Large-scale BESS facilities help balance supply and demand across the grid, thus improving stability and resiliency and reducing the likelihood of outages and enhancing energy security. In addition to the environmental benefits, construction of a BESS facility of this magnitude stimulates the local economy by creating construction jobs during installation and by generating fee and tax revenue for Maricopa County. 5.0 Location and Accessibility The Project is located on approximately 65 acres of private land; approximately 0.5 miles south of Elliot Road, 0.25 miles east of Dobbins Road, 0.75 miles north of Narramore Road (alignment), 1 mile west of 363rd Avenue, and 3.5 miles west of the community of Arlington. Access to the Project will be via existing roads and private easements. Primary access is anticipated to be provided via Wintersburg Road to Elliot Road from the north, with a potential alternative secondary access point located at the southwestern boundary of the Project, east 12 of 366th Avenue. Regional access to the Project will mainly be via Interstate 10 (I-10). The Project is expected to require minor extension and improvements of access roads on private land adjacent to the Project area. The on-site parking and staging facilities for construction traffic will be located in the vicinity of the primary site access, a significant distance away from any residences. As would be expected with any development, the Project is expected to generate construction and material delivery truck trips during the construction phase. Construction is anticipated to start in 2026 or later and continue for approximately 18 to 24 months. The peak of construction will require approximately 20 semi-trucks per day delivering materials to the site from I-10. A limited number of additional localized truck trips may be needed to meet construction water demands and will come from the west and/or north, avoiding Arlington Elementary School. At its peak, Project construction is anticipated to require a workforce of approximately 300, adding approximately 300 vehicles per day to Wintersburg Road. These workers will be staying off-site and will be encouraged to carpool. The mobilization and demobilization of equipment used for earthwork, including scrapers, graders, water trucks, compactors, truck- mounted post drivers, skid loaders, and forklifts, is anticipated to generate a minimal amount of traffic. Due to the remote location of the site and low traffic volumes, traffic impacts to the adjacent road system will be minimal. Traffic generated by the normal operation of the Project will be minimal. It is anticipated that up to five persons will be working periodically to maintain the facility. The Applicant will maintain its commitment to minimizing the impact of construction traffic impacts on traffic in and around Arlington Elementary School and the majority of residences on the east side of 355th Avenue. All construction traffic, both workforce and construction material deliveries, will access the site from the Wintersburg exit off I-10 to the north to funnel traffic away from both Arlington Elementary School and the residences located east of 355th Avenue and north of Southern Avenue. The Applicant will meet with Arlington Elementary School District officials in advance of construction to discuss traffic safety. 6.0 Circulation System Because of the nature of the proposed solar project development, no formal traffic circulation or coordinated street system will be needed to support the Project. As stated above, access to the site will be via existing roads and private easements. The proposed locations of these access points will be shown on the Plan of Development site plan. Inside the Project site, access to Project facilities will be provided via perimeter roads and access ways to the BESS facilities and O&M building. These will be shown on the Plan of Development site plan. These Project roads will be unpaved and maintained to reduce fugitive dust. 13 7.0 Development Schedule 7.1 Phasing Schedule The Applicant will construct the Project in response to market demand. The timing of construction of the Project or phases (if applicable) will ultimately depend on market conditions and the timeline of Project approvals. Regardless of timing and phasing, all construction will be subject to County oversight. The Applicant is aware that County drainage regulations require that the drainage of the overall site or any interim phase functions in an acceptable manner regardless of phasing. The Applicant acknowledges that this may require the development of interim drainage facilities in earlier construction phases. Each phase of development will be constructed with the requisite drainage controls to manage the respective on-site and off-site stormwater runoff in accordance with County design guidelines. Temporary facilities, such as office trailers, laydown yards, containers, construction warehousing buildings up to 40 feet in height, parking areas, and equipment storage areas will be required from move-on to completion of construction. Temporary facilities will be removed upon the completion of construction. Up to 300 construction workers will be employed during construction, and this workforce will vary with phases of construction. As previously indicated, the Applicant will coordinate construction traffic management with the Arlington Elementary School District. 8.0 Community Facilities and Services During operations, the Project will have no impact on community facilities and services such as schools and parks, as the Project is anticipated to only require a minimal number of full- time employees. 8.1 Emergency Response Plan The Project will incorporate safety systems for the solar project and the battery storage system that are required by code and the agencies having jurisdiction as appropriate. In addition to code compliant safety systems, it is important that key stakeholders, particularly the first responders, have a deep understanding of these safety systems and the associated technologies. As part of the Project, the Applicant will be engaging with local first responders to offer formal and informal training opportunities and to solicit feedback on the site design to ensure it is meeting their expectations i.e. site access points, emergency road designs, alarm equipment designs, etc. The Applicant has prepared an Emergency Response Plan for the existing Sun Streams projects in the immediate vicinity and will update that plan to cover this Project prior to construction. The plan specifies notification, assembly, accountability, and evacuation planning in the event of an emergency at the PVNGS, as the site is located within the 10-mile 14 Plume Exposure Pathway Emergency Planning Zone (EPZ) for PVNGS. The agencies having jurisdiction on the Project have approved three BESS projects in the immediate vicinity to the Project site (Sun Streams 3, Sun Streams 4, and Sun Basin 1) based on design review, Hazard Mitigation Analysis, Emergency Response plans, and first responder training completed for these projects. The Sun Basin VII Project will follow this precedent and offer the same materials and trainings prior to construction. 9.0 Public Utilities and Services 9.1 Fire Protection Fire response services for the area are provided by the Arizona Fire and Medical Authority (AFMA). The AFMA has three districts: North County Fire & Medical District, South County Fire & Medical District, and Buckeye Valley Fire District. The Project site is located between the South County Fire and Medical and Buckeye Valley Fire Districts. The nearest fire station is AFMA Fire Station 322, located approximately 4.7 miles northeast of the Project site. On- site driveways will provide egress for emergency and fire department access. Longroad has experience coordinating with AFMA on its neighboring Sun Streams projects, and would continue that coordination for the Sun Basin 7 Project. This includes design consultation, site visits, and trainings prior to construction and throughout the Project life. All materials used on the site will be managed according to applicable federal, state, and local regulations. 9.2 Police Protection The Maricopa County Sheriff’s Office, operating out of one main station in Avondale and a satellite station in Buckeye, provides protective services for the area. The Project site is located within the District II patrol area, and the nearest police substation is located at 920 E. Van Buren Street in Avondale. 9.3 Water and Wastewater Resources The Project will not impose any new water or wastewater requirements on the area. The site is located within an Arizona Department of Water Resources (ADWR) regulated Active Management Area (AMA). The need for water on the site during operations will be minimal, necessary only for the needs of employees. Water for construction purposes will be delivered to the site. Portable toilets will be used during construction. As indicated above, during operations there could be up to five full-time employees on the site. The potable water needs of five employees will be provided via bottled water or from ADWR-exempt wells. This insignificant amount of water use does not require a Public Water System. The wastewater generated at the facility during operations is anticipated to be treated with on- site wastewater treatment facilities, such as a conventional septic tank system or similar 15 alternative system as regulated by Arizona Department of Environmental Quality and administered by Maricopa County Environmental Services Department. 9.4 Electric Arizona Public Service (APS) is the electrical service provider for this area. The Applicant will coordinate with electrical service providers in the area as needed throughout the construction and operation of the Project. 10.0 Drainage and Grading 10.1 Drainage Design A Preliminary Drainage Report was prepared to provide hydrologic analysis for the Project and identify potential constraints as well as preliminary conveyance and retention design on the Project site (Exhibit A). Stormwater runoff generally flows from the northwest to southeast across the site. The existing flows are generally a maximum of about 12-inches deep and do not extend across the entirety of the effective floodplain limits. The Project site is located within Federal Emergency Management Agency (FEMA) Zone A Flood Hazard Area, Zone A includes areas with a one percent annual chance of flooding and a 26 percent chance of flooding over the life of a 30-year period. However, recent upstream development has effectively cut off flows historically impacting the Project site. The FEMA floodplain is not representative of existing site conditions for this Project. Offsite runoff will continue to be accepted and conveyed through the site via engineered channels and spreader basins, consistent with the existing drainage patterns. All onsite runoff generated from the Project will be retained onsite. The Project will acquire necessary permits and permissions before developing within any floodplains. A floodplain use permit is being pursued in support of development within the Zone A floodplain limits within the Project. The battery units within the floodplain limits and all permanent habitable structures shall be set above the regulatory flood elevation. The Applicant will also coordinate with the U.S. Army Corps of Engineers in the unlikely case that there is limited construction within any jurisdictional waterways determined to be located on- site. Developed areas within Maricopa County are required to regulate stormwater discharge such that net flow rates and flow volume exiting from the site are equal to or less than the predevelopment rate. This is often controlled through the construction of retention basins. The proposed drainage infrastructure to manage stormwater for the Project consists of engineered channels, retention basins, and spreader basins to manage stormwater such that flows are not increased as a result of development while also maintaining historical drainage patterns. Peak flow rates discharged from the Project boundaries will not exceed pre-development conditions due to the onsite retention being provided. 10.2 Grading Design The Applicant plans to minimize the amount of earthwork required for this Project where 16 feasible. Retention basins and wash corridors for stormwater conveyance are proposed in locations with existing lower grade and along existing flow paths. The Project will grade areas alongside the BESS facilities to act as a fire break. Otherwise, grading activities will not involve significant dredging or filling within major washes or any potential jurisdictional waterways determined to be located on-site. As detailed above, the Applicant is prepared to address appropriate permitting requirements of both the Maricopa County Flood Control District and U.S. Army Corps of Engineers, as necessary. 11.0 Environmental Impacts 11.1 Noise When the Project is fully operational, it is not anticipated that there will be any regular activities on the site that will result in discernable off-site noise. The equipment used for performing earthwork and installation of facilities could temporarily produce noise that is noticeable off- site during construction. Due to the remote location of the Project and presence of existing energy infrastructure in the area, the Project will have minimal impacts related to noise. 11.2 Air Quality The Applicant will use construction dust control measures as required by Maricopa County to limit fugitive dust emissions from the site. Details of the construction dust control plan will be submitted and approved under a separate permit through the Maricopa County Environmental Services Department. Dust control measures will be supported in part by minimizing the areas requiring ground disturbance and applying water, as necessary. The Project will not produce any noticeable odors. 11.3 Visual Resources The Project is not expected to significantly affect the visual quality of the area because it is located in an area with considerable existing energy generation facilities present, is on relatively flat desert land, will have a relatively low profile on the landscape, is several miles from the nearest population center, and is located in an area that does not provide recreational opportunities or attract public attention. The visually dominant features of the area are the existing PVNGS, the natural-gas-fired power plants, solar projects, and transmission lines. 11.4 Biological Resources Information was obtained from both the U.S. Fish and Wildlife Service and the Arizona Game and Fish Department (AZGFD) regarding the potential occurrence of special-status species within the Project area. The Project is sited outside of areas designated for environmental resource conservation, such as Areas of Critical Environmental Concern, Important Bird Areas, National Wildlife Refuges, Wilderness Areas, important migratory pathways or stopover sites, or other specially designated areas. The Project is co-located with existing energy infrastructure in an industrial location and does not contain designated critical habitats for protected species or wetlands. There are sensitive species with the potential to occur in the Project area; however, potential impacts to sensitive species will be avoided or minimized by 17 implementation of prevention, minimization, and mitigation measures. Zachary Kobza, P.E. Planning & Development 301 W. Jefferson St., Suite 170 Phoenix, Arizona 85003 Phone: (602) 723-5248 Fax: (602) 506-8762 www.maricopa.gov/planning Email address: Zachary.Kobza@maricopa.gov Planning & Development Engineering Plan Review Date: October 30, 2025 Memo To: Darren Gerard, AICP, Planning Manager, Department of Planning & Development Attn: Andrew Lorentzen, Planner, Planning & Development Services cc: Bob Fedorka, PE, Engineering Manager, Planning & Development From: Zachary Kobza, PE, Senior Plans Examiner Engineer, Planning & Development Subject: Z250031 – Sun Basin VII APN(s): 401-430-34G Engineering Review has reviewed the first plan and report routed for review on 10/14/2025, for the subject application and has the following objections: DRAINAGE PLAN REVIEW 1. OFFSITE HYDROLOGY a. The “Existing Drainage Conditions” Figure is labelled as Figure 4, but should be Figure 3. b. On the “Existing Drainage Conditions” Figure, Drainage Area DA-1 at the southern end of the Project should be labelled “ON-1”. 2. ONSITE RETENTION a. Retention Volume Provided shown on the “Retention Basin Calculations Table” (Page 67) does not match the volume provided shown on the Preliminary Drainage Plan. The Table shows that RB-2 is not retaining the 100-Yr, 2-Hr volume required and Note 1 mentions retaining the greater of the First Flush or Modified Rational Method volume. Please show that RB- 2 is retaining the 100-Yr, 2-Hr volume required. 3. RETENTION DISPOSAL a. Also provide notes on the plans requiring retention basins to drain within 36 hours. FLOOD CONTROL DISTRICT REVIEW 1. The work proposed in the floodplain will require a Floodplain Use Permit issued concurrent with building permit(s) for site development. Page 2 of 2 STORM WATER QUALITY REVIEW/INFORMATION 1. The subject site is not located within the County’s Urbanized Area; and thus will not require a Storm Water Pollution Prevention Permit (SWPPP) from the County. This does NOT preclude the requirement to obtain a Notice of Intent to Discharge (NOID) from the State (ADEQ), as may be required. The following stipulations will apply: 1. Engineering review of planning and/or zoning cases is for conceptual design only. 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. 2. Based on the conceptual design nature of the information submitted, changes to the site layout may be necessitated by the final engineering design of the n drainage infrastructure. 3. Detailed Grading and Drainage (Infrastructure) Plans must be submitted with the application for Building Permits. Please contact me with any questions. Page | 1 Subdivision Infrastructure & Planning Program 301 W. Jefferson St. Phoenix, AZ 85003 S u b d i vi s io n @ m a ri co p a .go v e s d .m a r i c o pa .g o v The Maricopa County Environmental Services Department (MCESD) has completed review for the Sun Basin VII Project planning case(s). Please note the following MCESD requirements for site development: Onsite Wastewater (Septic) – A Notice of Intent to Discharge application for a septic system is required for any construction. Application must be submitted to the MCESD Onsite Wastewater Program. • Wastewater is not permitted to discharge to an adjacent parcel’s septic system. • If conducting food service in unincorporated Maricopa, a grease trap will be required by Onsite Wastewater program. • Setback requirements must be maintained per Arizona Administrative Code, Title 18, Chapter 9, Article 312, C (Features Requiring Setbacks). For Onsite Wastewater related questions, please contact the Onsite Program at (602) 506- 6666 or by email at septicquestions@maricopa.gov. Additional Notes – *It should be noted that this document does not approve the referenced project. Comments are provided for the benefit of the applicant for MCESD permit requirements and as an advisory to Maricopa County Planning and Development Department. Other Maricopa County agencies may have additional requirements. Final review and approval will be made through Planning and Development Department procedures. Applicant may need to submit separate applications to the Maricopa County Environmental Services Department for approval of proposed facilities regulated by the Department. Review of any such application will be based on current regulations at the time of application. Project Name: Sun Basin VII Project Primary Contact Name: Courtney Van Winkle Planning Application Type: Zone Change with Overlay APN(s): 401-43-034 Reviewer: Joseph Churby, P.E. Email: Joseph.Churby@maricopa.gov Phone: 602-372-2754 Planner Name: Andrew Lorentzen Planning Case #: Z250031 Date: October 30, 2025 Water and Waste Management Division DATE: January 22, 2026 TO: Planning & Zoning Commission From: Andrew Lorentzen, Planner SUBJECT: Z250031 – Sun Basin VII Agenda Item: 3 After printing of the staff report, the applicant requested an additional IUPD deviation (C.10) removing loading zone requirements from the proposed IND-2 IUPD zoning district. Staff has no objection to this request as parking requirements are already requested to be eliminated from the proposed BESS facility. c. The following IND-2 IUPD standards shall apply: 1. Minimum Front Yard – 100’ 2. Minimum Side Yard -100’ 3. Minimum Rear Yard – 100’ 4. Minimum Parking: No Parking required 5. Minimum Screening: Minimum 6’ tall chain-link fences adjacent to rural/residential zoning boundaries, including attached barbed wire or concertina wire under 8’ in height, and allow all gates to have no attached screening. No screen wall, berm or hedges required along front property lines. 6. Minimum Paving: Alternative surfacing materials or methods approved by Maricopa County Air Quality to minimize dust pollution, such as but not limited to, native compacted soil or aggregate base course, may be used in driveways and parking areas. 7. Minimum Landscaping/Buffering: No landscaping or irrigation required. No screening required adjacent to rural and residential zoning districts. 8. Minimum Sight Visibility Triangles: Within sight visibility triangles at any intersection, on-site chain-link fences without screening materials can exceed a height of 2’. 9. The IUPD overlay shall limit entitled uses to power generation and distribution, BESS facilities and ancillary uses. 10. Loading and Unloading: none required. Attachments: Applicant correspondence (1 page) Andrew Lorentzen (PND) From: Courtney Van Winkle <cvanwinkle@kpenvironmental.com> Sent: Monday, January 12, 2026 5:39 PM To: Andrew Lorentzen (PND) Cc: Alyssa Menzel; Caleb Weeks Subject: Re: Z250031 - Sun Basin VII - Draft conditions of approval. This Message Is From an External Sender This message came from outside your organization. Please use caution when corresponding outside the county. Hi Andrew, Hope you had a good weekend. Our only comment on the draft conditions would be to add one item to the development standard stipulations: c.10. Loading and Unloading: none required. Otherwise, we do not have any revisions to the conditions. Thank you very much, Courtney Van Winkle, Project Manager 760.685.0269 cvanwinkle@kpenvironmental.com https://www.kpenvironmental.net