Photo courtesy of CDM Smith

The Delta Water Supply project in Stockton earned an Award of Merit in the Civil Works/Infrastructure category.

Touted as the largest capital improvement project in Stockton's history, the Delta Water Supply Project (DWSP) improves water reliability, protects groundwater and provides drought protection for the city, which was no longer able to rely on pumped groundwater and purchased water for its municipal supply.

Completed in June 2012, the DWSP pumps surface water from the Sacramento-San Joaquin Delta. The initial permit allows the city to draw the same amount of water from the city's wastewater treatment plant as the city puts in, creating one of the first indirect potable water-recycling projects in Northern California. The $175.9-million, two-stage design-build approach delivered the 30-mgd water treatment plant and more than 18 miles of raw-water and treated-water pipelines. An ultimate capacity of 160 mgd is planned.

The DWSP included design and construction of the state-of-the-art treatment process; administration, operations and maintenance buildings; solids settling and drying basins; treated- and reclaimed-water pump stations; and a 4-million-gallon treated-water storage reservoir.

The project required the design and installation of 12 miles of new 54-in.-dia raw-water pipeline and more than six miles of 54-in.-dia, 42-in.-dia and 36-in.-dia treated-water pipelines and construction of seven microtunnels.

The campus earned LEED-Gold certification.

Delta Water Supply ProjectStockton

Key Players

Owner: City of Stockton

Design-Builder: CDM Smith, Walnut Creek

Structural/Civil/MEP Engineer: CDM Smith, Bellevue, Wash.

Tunneling: Bennett Engineering Services, Roseville; Vadnais, Vista

Electrical: San Joaquin Electric, Stockton

Pipeline: Sundt, Tempe, Ariz.

Earthwork/Sitework: Teichert, Stockton

HVAC/Plumbing: KMS, Livermore

Roofing: Legacy Roofing, Sacramento

Concrete/Structural/Steel/Process Mechanical: Monterey Mechanical, Oakland

Prestressed Tank: DYK Inc, El Cajon

Painting: Mason Painting, Rancho Cordova

Yard Piping: Preston Pipelines, Lathrop