Seismic Retrofit and New WR5 Reservoir:

• Owner: Walnut Valley Water District
• Cost: $1,600,000

Walnut Valley Water District is located 20 miles east of Los Angeles in the San Gabriel Valley, encompassing an area of approximately 28 square miles serving approximately 100,000 multi-use consumers in six communities. The District's potable water distribution system consists of 28 reservoirs, 16 pump plants, and 37 pressure regulating stations, and many miles of pipelines, serving water to approximately 26,500 connections in 14 pressure zones.

Perliter & Ingalsbe had originally designed most of the District's facilities since 1950s and also provided engineering services for seismic retrofitting of many reservoirs. The existing 1.65 MG reservoir WR-5 is one of the last few District reservoirs which required seismic retrofitting. Additionally, the design and construction of a new 1.0 MG steel reservoir at the same site was necessary to meet the required storage capacity for Pressure Zone 770.

Perliter & Ingalsbe provided a full range of services, including planning, preliminary design, final design, and construction management.

Major Components and Special Features:

• Seismic Retrofit of the Existing Reservoir:
• Replacing existing concrete ring beam foundation with new
• Tank anchors
• Flexible pipe joints
• Reducing height of tank
• Replacing steel roof with new aluminum dome roof
• Upgrading appurtenances and instrumentation
• Painting and coating

• New Reservoir:
• New 1.0 MG steel tank with aluminum dome roof
• Reservoir appurtenances, including ladder, hatches, gravity vent, piping, pressure gages, level transmitter, piping, vaults, etc.
• Site electrical system, controls and SCADA
• Cathodic protection system

• General Improvements:
• Grading, paving, concrete curb and gutter
• Access roads, fencing, entrance gates and monument walls,
• Site drainage
• Landscaping and irrigation system

• Challenges and Special Features:
• One tank to remain in operation during construction
• Narrow access road
• Limited staging and storage area
• Site located within the affluent residential area