The SWP's 4-Pumps Program

When Banks Pumping Plant was constructed, only seven of its 11 pumps were installed. In 1986, the additional four pumps were installed, increasing the plant's capacity to pump and divert water during wet years for offstream storage and groundwater recharge. However, DWR was required to mitigate for additional fish loss anticipated by the increased pumping by funding programs to restore striped bass, steelhead trout, and chinook salmon populations.

DWR and the Department of Fish and Game signed the Delta Pumping Plant Fish Protection Agreement in 1986 to offset adverse fishery impacts caused by the diversion of water at the Banks Pumping Plant. The agreement is commonly known as the 4-Pumps Agreement because it was subsequently identified as mitigation for the additional four pumps. Among its provisions, the agreement provides methodology to estimate annual fish losses and mitigation credits, implements fish mitigation projects and associated funding sources, and evaluates potential fish mitigation projects for funding under the agreement.

The agreement established a $15 million lump sum program and an annual mitigation program, funded by DWR, to pay for such projects as improving salmon spawning habitat in the Sacramento River and San Joaquin tributaries, creating a law enforcement unit to combat poaching in the Bay Delta estuary and upstream into the Sacramento and San Joaquin river systems, stocking yearling striped bass, and expanding and modernizing Merced River Fish Hatchery. Some recently funded projects include fish screens in Suisun Marsh, fish screens and a ladder in Butte Creek at Durham Mutual Dam, a fish ladder in Butte Creek at Parrot-Phelan Dam, exchange of groundwater for surface water diversions in Mill Creek currently and Deer Creek within the next year, improvement of salmon spawning habitat on the Stanislaus, Tuolumne, and Merced rivers. Several of these projects primarily benefit spring-run salmon.