Thousand Oaks Reservoir - 2013 APWA Project of the Year Award, Santa Barbara and Ventura Counties:
- Owner: Calleguas Municipal Water District
- Cost: $12,803,000
The existing Calleguas Municipal Water District 7.0 MG steel tank, located in the City of Thousand Oaks, required seismic retrofit and re-coating as recommended by Perliter & Ingalsbe in a previously completed study. It was also found that the reservoir is not situated at the optimal elevation to meet imminent and future hydraulic requirements of the system. The District's staff determined to demolish the existing 40' high steel tank and construct two new buried concrete reservoirs with a total capacity of 7.0 MG at a higher elevation with 20' water depths to maximize usage.
Perliter & Ingalsbe was engaged to perform preliminary planning, detail design and construction support services for this complex and challenging project. The project was completed in 2013 and received "Project of the Year Award" from APWA, Santa Barbara and Ventura Counties.
Major Components and Special Features:
- Demolition of existing 7.0 MG steel tank
- Two new 20' deep buried cast-in-place concrete reservoir units with total storage capacity of 7.0 MG
- Extensive grading, involving 80,000 CY of cut and 90,000 CY of fill
- Reservoir access road and facility perimeter road
- 48" inlet pipe and valves
- 48"- 2500' long outlet pipe and valves
- 24" reservoir overflow, 12" drain and 6" sub-drain piping
- Five large concrete vaults
- Washdown piping inside reservoir for cleaning
- Hatches, ladders, stairways, gravity vents, etc.
- Electrical power supply, controls and instrumentation
- 18' wide reservoir access and perimeter roads, entrance gate and retaining walls
- Security features, including intrusion alarms, security fencing, etc.
- Landscaping and irrigation system
- Geotechnical challenges because of adverse bedding condition
- Raising of reservoir pad by 20 feet using soil cement
- Proximity to affluent residential area
- Narrow access road
- Practically no staging and storage space
- Two-phase construction to facilitate continuous water supply during construction
