Thursday March 21, 2024
California Department of Water Resources —
Spring is an important time for water project operators to fill reservoirs ahead of dry months. It also is an important migration window for many native fish species. Steelhead trout in Central Valley rivers are listed under the U.S. Endangered Species Act as threatened. As a result, the State Water Project (SWP) and Central Valley Project (CVP) monitor steelhead at the pumping plants near Tracy that move water to the Santa Clara Valley, San Joaquin Valley, and Southern California.
The State Water Project and Central Valley Project have decreased pumping to less than half of maximum capacity since January 1 to protect migrating fish. Now, the SWP and CVP are approaching the maximum number of steelhead trout that can be collected at the pumps from December 1 through March 31 of each year under rules established by the National Marine Fisheries Service (NMFS). The water projects may reach the maximum allowable steelhead collected under those rules within the next few days. Steelhead are collected live in front of the fish screens at the SWP pumping facilities and released into Delta channels. Studies show that approximately 95 percent of the steelhead collected this way survive their journey to the ocean.
Fish monitoring stations in the Sacramento Basin have seen a significant increase in juvenile steelhead production this past year which may account for the relatively higher numbers of steelhead observed in the south Delta this winter.