and SWP supplies. In addition to supplying the main CVP and SWP canals, San Luis Reservoir also supplies water to the Santa Clara Valley via the Pacheco Tunnel and Hollister Conduit, which travel under the Diablo Range. At the western end of the tunnel, the water is stored behind San Justo Dam, an earthfill dam completed in 1986. These facilities are all part of the San Felipe Division of the Central Valley Project. The San Luis & Delta-Mendota Water Authority represents the 29 federal water contractors served by the San Luis Unit, consisting of a combined service area in the San Joaquin and Santa Clara Valleys. The Authority operates the Federally owned portion of the San Luis Reservoir and water supply infrastructure. Environmental issues Before San Luis Dam was built, most of the pumping from the Delta occurred during the summer when there is high demand for irrigation. The construction of San Luis Dam enabled the additional capture of winter flows that would otherwise be lost to the sea. However, water pumping during certain times of the winter and early spring interfere with fish migration, notably the Sacramento River chinook salmon. The pumping changes the primary direction of water flow in the Delta from east–west to north–south, confusing the fish. As a result, certain environmental restrictions have been in place since the 1990s to limit pumping during the spring chinook run (March–April). This has led to frequent low water levels at San Luis Reservoir; in late summer 2016 it fell to 10 percent of capacity, the lowest since 1991. These restrictions have been criticized by water agencies as too stringent, especially since California is in a long-term drought. During winter 2016 at least of water was allowed to drain from the Delta into the Pacific instead of being pumped into San Luis Reservoir. In December 2016, Congress passed a bill allowing increased water pumping during times when fish are not at high risk. This will generally allow more water to be stored at San Luis Reservoir. The bill will require daily monitoring of fish to ensure environmental laws are not violated, instead of relying on hard limits which may not match current conditions. California Senator Dianne Feinstein remarked that "the goal... is to run California's water system based on good science, not intuition." Proposed expansion In 2013, the Bureau of Reclamation proposed raising the BF Sisk Dam by to create