Owner: Reclamation District 108
Contract value: $7,220,473
This project is one of the largest fish screening facilities in the Sacramento River basin. It consists of a 250 ft long by 45 ft tall reinforced concrete structure spanning the entrance to the District's pumping plant forebay. The structure supports fourteen stainless steel screen panels each 16 ft wide by 12 ft tall with precise 3/32 inch openings between the screen wires which permit water flow to the irrigation pumps, but obstruct passage of juvenile fish. The total screen area is over 2,500 square feet accommodating irrigation flows up to 830 cubic feet per second. Adjustable flow distribution louvers behind the screen panels control hydraulic uniformity through the screens. The facility is also equipped with a continuous-travel brush mechanism which sweeps the entire screen surface once every five minutes cleaning off water-born debris.
Approximately 2,000 linear ft of temporary and permanent sheet pile was driven for the screen structure cofferdam and the permanent retaining walls for the approach ramps on either side of the facility. The screen and approach ramps are supported on 225 steel H-piles.
It was critical that construction of the fish screen facility be accomplished without interrupting irrigation water deliveries or interfering with fish migrations in the Sacramento River. Shimmick Construction was also responsible for the generation and implementation of a value engineering proposal that eliminated the need for a 5 ft thick concrete slab beneath the screen structure resulting in savings of time and money to the Owner.