TO:Andrew P. Powers, City Manager
FROM:Nader Heydari, Public Works Director
DATE:September 23, 2025
SUBJECT: Wilder Reservoir Improvements Project (CI 5294) RECOMMENDATION:
1. Authorize staff to advertise for construction bids for the Wilder Reservoir Improvements Project (CI 5294).
2. Find that the Project is Categorically Exempt from California Environmental Quality Act (CEQA) pursuant to 14 CCR 15301 (repair/maintenance of an existing facility).
LEVINE ACT ITEM: No
FINANCIAL IMPACT:
No Additional Funding Requested. Minimal staff time and costs required to advertise for bids is included in the Adopted FY 2025-26 Water Fund Budget. $2,073,000 in carryover budget is available from FY 2024-25 Water Capital Fund Budget for the Wilder Reservoir Improvements (CI 5294). $1,000,000 is included in the Adopted FY 2025-26 Water Capital Fund Budget for a total project budget of $3,073,000. Additional funding for construction costs may be requested at the time of construction contract award depending on the bids received.
BACKGROUND:
The City's water system serves over 17,000 customer accounts and approximately 50,000 residents. The City receives treated imported water from the Calleguas Municipal Water District and distributes water to roughly 36 percent of the City via 16 water storage reservoirs constructed between 1961 and 2002, with a total storage capacity of over 35 million gallons. Thirteen of the reservoirs are above- ground steel reservoirs, and three are partially buried concrete reservoirs.
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The City’s Wilder Reservoir is located on Wilder Street (Attachment #1) in the eastern segment of the City's system, with a capacity of approximately 980,000 gallons. The reservoir was built in 1964, has a height of 24 feet, and is 84 feet in diameter. Over the years, Wilder Reservoir has received some improvements, but it now requires complete rehabilitation to continue operating effectively.
The City’s 2018 Citywide Reservoir Seismic Evaluation/Structural Report included a priority list of seismic and structural rehabilitation needed at each reservoir to maintain high operational and safety standards. Upgrades have been completed at the Lang Ranch and Tara Reservoirs, and work at La Granada Reservoir is in process this year. Wilder Reservoir is the next reservoir on the rehabilitation priority list to be completed.
This project will include upgrades to the tank, altitude valve vault, and the surrounding access road. The interior coating is deteriorating and no longer provides corrosion protection, while the exterior coating has reached the end of its useful life. Additionally, the tank will be retrofitted to meet current seismic standards, thereby mitigating damage in the event of an earthquake. There are some limitations at the Wilder Reservoir site, such as its relatively small size and its location, being surrounded by residences on two sides. Careful planning and construction coordination are necessary to overcome these constraints.
On March 19, 2024, City Council approved a Professional Services Agreement with HDR Engineering, Inc. (HDR), in the amount of $248,620 plus $24,860 in extra services, to provide a preliminary design report/condition assessment of the reservoir facility and preparation of construction contract documents for the Wilder Reservoir Improvements Project. The First Amendment to the contract for design services was approved by City Council on November 19, 2024, in the amount of $65,091, increasing the not-to-exceed amount to $313,711. The First Amendment included additional design work related to a standby engine generator, fire- hardening improvements for the existing pump station building, and an above- ground pressure-reducing station.
DISCUSSION/ANALYSIS:
The work for the Wilder Reservoir Improvements Project includes the installation of a temporary water system to allow for the short-term shutdown of the reservoir.
There will be removal of both interior and exterior coatings, focusing on lead containment and disposal. The project also entails the elimination of failed/ corroded tank structure and associated appurtenances. Additionally, a cathodic protection system will be installed within the tank, along with electrical work that includes the installation of a standby engine generator and an automatic transfer switch. Fire hardening of the pump station building will be carried out, and the Wilder Reservoir Improvements Project (CI 5294)
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altitude valve will be replaced, along with improvements to the piping and valve vault. These enhancements aim to improve the overall functionality, reliability, and safety of the reservoir system.
The project plans and specifications were completed by HDR and approved by City staff in August 2025. The documents are available for review upon request to the Public Works Department by e-mail at [email protected] or by phone at (805) 449-2400.
A summary of the estimated project cost is shown below.
ESTIMATED PROJECT COST SUMMARY
Preliminary Design Report, Design and Engineering (previous) $ 248,620 Additional Design Services (previous) $ 24,860
Amend. No. 1 - Fire Hardening and Standby Generator (previous) $ 65,091 Engineering Support During Construction (future) $ 125,000 Construction Phase Estimate (future) $ 2,772,000
Total Estimated Project Cost $ 3,235,571
The overall project cost (including contingencies, design services during construction/testing, and project management) is estimated at $3,235,571.
The tentative schedule for completion of the project is as follows:
Bidding Fall 2025
Award of construction contract Fall 2025
Start of construction Late Winter 2026
Construction completion Fall 2027
Staff recommends that the project be advertised for bid. Once bids are received, staff will make a recommendation at a future City Council meeting for the award of the construction contract.
The project is categorically exempt from CEQA per section 15301 (repair/maintenance of an existing facility).
Community Outreach: Although the project is not anticipated to negatively impact adjacent residents, City staff will contact residents surrounding the reservoir site and work with them closely prior to construction.
This project meets City Council’s Top Ten Priorities #9 “Public Works Infrastructure Investments.”
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CIP PROJECT PRIORITY (as outlined in FY 2025-26 and FY 2026-27 CIP Program Budget).
Priority Two – Necessary, but not essential, and there could be consequences if deferred.
COUNCIL GOAL COMPLIANCE:
Meets the following City Council goals:
C. Operate City government in a fiscally and managerially responsible and prudent manner to ensure that the City of Thousand Oaks remains one of California's most desirable places to live, work, visit, recreate, and raise a family.
F. Provide and enhance essential infrastructure to ensure that the goals and policies of the Thousand Oaks General Plan are carried out and the City retains its role and reputation as a leader in protecting the environment and preserving limited natural resources.
PREPARED BY: Paul Weinstein, Associate Analyst
Attachments:
Attachment #1 – Vicinity and Location Maps
DPW: 850-20\ev\Council\2025\092325\CI5294\Wilder Reservoir Improvements Project staff report.docx