California and federal water officials signed new rules for operating the state’s system of reservoirs, canals and dams, which serves 30 million people and 4 million acres of irrigated farmland. The plan, approved by the Biden administration and the Bureau of Reclamation (BOR), aims to balance water reliability with protections for endangered fish and improved responses to multi-year droughts.
The record of decision covers the operation of the Central Valley Project (CVP) and the State Water Project (SWP) in the Sacramento-San Joaquin Delta for water supply deliveries from the north at Lake Shasta to Southern California.
“The completion of new operating rules for the Central Valley Project is the cornerstone of our efforts to address record drought and changing climate conditions in California,” said BOR Commissioner Camille Calimlim Touton. “The plan helps build the state’s resilience to drought, both for water users and the environment.”
She continued, “It also dovetails with the significant ecosystem investments and infrastructure projects that Reclamation has funded, including new water storage, capacity improvements, groundwater banking, and the development of a drought plan for the south-of-Delta.”
After considering several alternatives, BOR implemented Alternative 2, the Multi-Agency Consensus Proposal. According to the record of decision, the alternative introduces a new framework for operating Shasta Reservoir, improving protections for the coldwater pool during multi-year droughts and reducing temperature-related mortality of winter-run Chinook salmon.
According to the record of decision, Alternative 2 includes actions to reduce harm to Delta smelt, such as controlling reverse flows in the south Delta and addressing turbidity levels. While many stressors on Delta smelt are beyond Reclamation’s control, the plan also includes measures like supplementation to help address survival challenges caused by low fish numbers.
BOR said Alternative 2 is deemed the environmentally preferred alternative, aiming to balance ecological needs with water management. However, the plan is a double-edged sword. According to an appendix of the record of decision, while it is expected to benefit winter-run Chinook salmon by reducing water temperatures and increasing flows below Keswick Dam, it is also “likely to adversely affect” the same species under certain conditions. For example, water releases designed to ensure cooler temperatures for spawning may later shift to warmer releases to preserve water for egg incubation, potentially negating some of the benefits.
The decision did note that the U.S. Fish and Wildlife Service and National Marine Fisheries Service were consulted for compliance with the Endangered Species Act. The agencies said the alternative would not likely jeopardize threatened or endangered species or destroy or adversely modify their habitat and made some minor recommendations.
Details for agriculture are scant, but the chapter describing the alternatives said the Department of Water Resources would continue to operate the water barriers to maintain water levels for diversions in parts of the South Delta.
However, the San Luis & Delta-Mendota Water Authority—the water district representing San Joaquin County in the Central Valley—said in a statement that it recognizes BOR’s efforts to address issues, including adopting a more effective adaptive management approach incorporating new scientific insights. Still, water district members have mixed feelings about the final decision.
“Today’s action by Reclamation elicits mixed reactions—On the one hand it attempts to better align coordination between the Central Valley Project and State Water Project operations,” said Federico Barajas, executive director of the San Luis & Delta-Mendota Water Authority. “On the other hand, the selected operations regime will reduce surface water supply reliability for the communities, farms, and ecosystems reliant on water provided by the Water Authority’s member agencies by nearly 100,000 acre-feet annually, complicating efforts of our members to provide affordable surface water supplies and sustainably manage groundwater.”
Gov. Gavin Newsom (D) said that adopting the framework is a crucial step toward integrating future water projects, such as the Sites Reservoir and Delta Conveyance Project, to secure the state’s water supply. He emphasized that the framework offers a more balanced water management approach and provides greater flexibility to address climate-driven extremes of drought and flood.
According to CalMatters, the new rules focus on operating two major water delivery systems but are just one element of the broader Bay-Delta Water Quality Control Plan, which is undergoing a separate and contentious update. In the coming year, the state water board will decide whether to enforce stricter flow requirements through the Delta or pursue voluntary agreements that involve water users restoring stream habitats for salmon and other fish. — Charles Wallace, WLJ contributing editor
