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PL26-0026 (Special Conditional Use Permit)
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LOCATION MAP
PROJECT NO.: PL26-0026 (Special Conditional Use Permit)
APPLICANT: City of Chino Public Works Department
REQUEST: A request for approval for the Benson Reservoir Replacement and Improvements Project, which entails constructing and operating a replacement reservoir for the existing Benson Reservoir within the City’s Benson Water Treatment Plant, connecting the replacement reservoir to the system, and demolishing the existing reservoir within the Public (P) zoning district.
LOCATION: 11840 South Benson Avenue (APN: 1014-401-06)
RECOMMENDATION
recommendation
1) Adopt Planning Commission Resolution No. PC2026-010, adopting a Mitigated Negative Declaration (MND) for the Benson Reservoir Replacement and Improvements Project; and 2) Adopt Planning Commission Resolution No. PC2026-009, approving PL26-0026 (Special Conditional Use Permit), based upon the findings and subject to the departmental conditions of approval.
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SURROUNDING ZONING AND LAND USE:
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Existing Land Use |
General Plan |
Zoning District |
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Project Site - |
Water Reservoir |
Public/Institutional (P/I) |
P (Public) |
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North - |
Single-family residential |
Residential, 1 dwelling unit/acre (RD1) |
RD 1 (Residential/Agricultural) |
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East - |
Single-family residential |
City of Ontario |
City of Ontario |
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South - |
Vacant |
Residential, 1 dwelling unit/acre (RD1) |
RD 1 (Residential/Agricultural) |
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West - |
Single-family residential |
Residential, 1 dwelling unit/acre (RD1) |
RD 1 (Residential/Agricultural) |
BACKGROUND
The City of Chino provides potable water service to approximately 89,000 residents through 23,000 active metered service connections. One of the City’s primary water supply facilities is the Benson Water Treatment Plant (WTP), located at 11840 South Benson Avenue.
The Benson WTP treats groundwater from two on-site wells (Well 5 and Well 9) and one off-site well (Well 10). Treated water is conveyed to the existing Benson Reservoir (Reservoir No. 3) for storage prior to distribution into the City’s potable water system. The existing reservoir is a 1.5-million-gallon steel cylindrical tank constructed in 1961. After more than 60 years of service, the facility is approaching the end of its useful life and does not meet current structural and seismic design standards.
Engineering evaluations have identified several deficiencies, including inadequate seismic anchoring, insufficient freeboard capacity relative to modern standards, and potential foundation limitations. Given the reservoir’s critical role in maintaining system reliability, pressure, and fire protection, replacement of the facility is necessary to ensure continued operation of the City’s water distribution system. To address these deficiencies, the City is proposing the Benson Reservoir Replacement and Improvements Project. The project includes replacement of the existing reservoir with a new modern prestressed concrete reservoir, along with associated improvements such as piping modifications, access and site improvements, and drainage enhancements within the Benson WTP site.
Project statistics are as follows:
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Item |
Proposed |
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Project Area - |
1.3 acres |
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Lot Area - |
4.6 acres |
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Building Area - |
0.53 acres |
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Lot Coverage - |
15% |
ISSUES/ANALYSIS
Site Design
The Benson Reservoir Replacement and Improvements Project includes construction of a new water storage reservoir and associated infrastructure improvements within the existing Benson Water Treatment Plant (WTP).
The project will replace the existing 1.5-million-gallon steel reservoir with a new approximately 7.85-million-gallon prestressed concrete reservoir, significantly increasing storage capacity and improving overall system reliability. The new reservoir will be located in the northwestern portion of the site, in an area that is relatively flat, proximate to existing facilities, and optimally positioned to maximize tank diameter and storage capacity while avoiding conflicts with existing infrastructure.
The selected location is bounded by the property line to the north and west, Well 9 and associated piping to the south, and existing WTP facilities to the east. This configuration allows efficient integration with existing operations while maximizing usable storage volume.
The project also includes realignment and installation of new inlet and outlet pipelines to connect the reservoir to the Benson WTP and Booster Pump Station. The inlet pipeline will be located along the northeast quadrant of the reservoir and will consolidate multiple water sources to improve operational efficiency. Outlet piping will discharge through an underground vault equipped with a check valve to prevent water backflow, with pipe diameters ranging from approximately 20 to 24 inches.
Reservoir Structure
During the design evaluation process, a prestressed concrete reservoir was selected over a steel alternative due to its suitability for larger storage capacity, lower lifecycle cost, reduced maintenance requirements, and improved long-term performance. A flat roof configuration was also selected to provide a lower overall profile compared to a dome roof and to better suit Southern California conditions through its column-supported system, which enhances seismic performance. The increased height of the proposed reservoir supports compliance with current structural and operational design standards and addresses deficiencies in the existing reservoir, including inadequate freeboard capacity. A comparison of the existing and proposed reservoirs is provided below.
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Existing Reservoir |
Proposed Reservoir |
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Maximum Storage Capacity |
1.5 million gallons |
7.85 million gallons |
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Geometry |
Cylindrical |
Cylindrical |
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Diameter |
80 feet |
172 feet |
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Height |
44 feet |
58 feet |
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Material |
Coated Steel Reservoir |
Prestressed Concrete Reservoir |
The replacement reservoir will be designed in accordance with applicable industry and regulatory standards, including the American Water Works Association, State Water Resources Control Board Division of Drinking Water, City of Chino standards, and current structural and seismic design codes to ensure long-term durability and seismic resilience.
Key Benefits
The project provides several critical benefits to the City’s water system:
• Replaces aging infrastructure that is near the end of its service life
• Improves seismic safety and structural reliability
• Increases water storage capacity and system resiliency
• Enhances emergency response and fire protection capability
• Improves operational flexibility within the distribution system
Collectively, these improvements will strengthen the reliability and long-term performance of the City’s potable water system.
Public Noticing
A 30-day notice was mailed to all property owners within a 300-foot radius of the project site. In addition, a notice was published in the Chino Champion on April 18, 2026, and the City sent information out on the City’s social media platforms. In response to the public notice, no comments have been received. The notice meets legal noticing requirements.
ENVIRONMENTAL REVIEW
A Mitigated Negative Declaration (MND) (SCH#2026030443) has been prepared for the Benson Reservoir Replacement and Improvements Project by Dudek (dated March 2026) that was circulated for a 30-day review period from April 20, 2026 to May 20, 2026. The MND identified potentially significant environmental impacts to air quality, biological resources, cultural resources, geology and soils, noise, and tribal cultural resources which could occur as a result of the proposed project. However, mitigation measures have been identified that reduce impacts to less than significant levels. In accordance with state environmental law, the Mitigation Monitoring Reporting Program (MMRP) identifies each environmental mitigation measure, the time in which it will be implemented and the responsible party for monitoring its implementation. A draft copy of the MMRP is attached as Exhibit “A” to Planning’s Conditions of Approval.