Environmental

DWR, Reclamation seek permission to conserve California water storage

DWR, Reclamation seek permission to conserve California water storage
(photo courtesy California DWR)

The California Department of Water Resources (DWR) and the U.S. Department of Interior’s Bureau of Reclamation have submitted a petition to the State Water Resources Control Board to maintain water storage in California reservoirs.

After the driest three-year period on record, California experienced one of the wettest three weeks in January. But those extreme wet conditions have activated a water quality standard in the Sacramento-San Joaquin River Delta that, coupled with the extended dry period since then, could sharply reduce the water that can be retained or moved into storage for the State Water Project (SWP) and Central Valley Project (CVP).

The SWP provides water to 29 public water agencies that serve 27 million Californians and uses the water for hydropower generation. The SWP is a system of 32 storage facilities, 21 pumping plants, four pumping-generating plants, eight conventional hydroelectric plants and about 700 miles of canals and pipelines. Among these generating plants is 762 MW Hyatt at the foot of Oroville Dam.

The CVP supplies water to about 3 million acres of agricultural land in the San Joaquin and Sacramento valleys and provides urban water for millions of people and industrial water. In addition, water from the CVP is vital for the environment, wildlife and fishery restoration, and hydroelectric power production. The CVP’s major reservoirs are (from north to south) Trinity, Shasta, Folsom, New Melones, Millerton, and the federal share of San Luis Reservoir. The Shasta powerhouse has a capacity of 633 MW, Folsom 198.72 MW, New Melones 300 MW and Trinity 140 MW. San Luis Reservoir provides water to the 424 MW William R. Gianelli pump-generating plant.

According to a release, DWR and Reclamation are working to operate the state’s water system to maximize water supply while protecting species and the environment. However, California continues to experience unprecedented swings in weather impacting water management operations. Because of these swings, DWR and Reclamation are taking proactive measures to manage the state’s water supply to store and capture more water in preparation for a return to hot, dry weather in the next two months.

Both agencies submitted a Temporary Urgency Change Petition (TUCP) to the board requesting approval to modify compliance with delta water quality conditions specified in their water right permits, while proposing measures to avoid impacts on delta smelt. DWR and Reclamation typically would seek this kind of change during extremely dry conditions. But the swing to extremely wet conditions after extremely dry conditions has created challenges, and the projects are acting to enable additional opportunities for water storage while maintaining species protections.

The request for the TUCP follows protective actions taken by DWR and Reclamation under state and federal endangered species permits in late December and early January, including the “first flush” to reduce pumping and allow storm runoff to flow through the system to benefit native fish species. Recent monitoring shows the actions worked, with key fish species moving downstream of the delta and away from the direct influence of the SWP and CVP pumps.

The water quality and water right permits that dictate SWP and CVP operations require certain water quality conditions to be met at specific compliance points in the delta to provide favorable conditions for endangered fish species. In consultation with the Department of Fish and Wildlife, DWR and Reclamation are requesting that the State Water Resources Control Board temporarily move the compliance point in the projects’ water rights permits to ensure water quality sufficient to protect beneficial uses.

If approved by the board, these actions would allow DWR and Reclamation to move and retain more stormwater and runoff in the state’s reservoirs in preparation for continued dry periods.  A total of about 300,000 acre-feet would be saved for later use by the SWP alone.

The January storms did not end drought conditions, and California remains in a drought emergency. Regions that rely on the Colorado River system face increasingly severe water shortage conditions, and groundwater basins that serve communities in the Central Valley will not recover quickly from back-to-back years of drought and chronic overdraft, DWR said.