California water regulators have teed up what promises to be one of the state’s biggest debates on water in years, releasing a long-anticipated proposal Thursday to revive dozens of rivers, creeks and wetlands by reining in the draws of cities and farms.
The goal is nothing short of ensuring that sufficient water is flowing from the high Sierra to San Francisco Bay, to nourish vast and diverse landscapes, support fish and wildlife and halt the decline of the Sacramento-San Joaquin River Delta, the largest estuary on the West Coast and the hub of the state’s water supply.
The nearly 6,000-page document, an update to what’s known as the Bay-Delta Plan, focuses on boosting water flows, and limiting pumping, in the Delta and in the Sacramento River basin. A previous update, in 2018, did the same for the San Joaquin River basin, to the south. Taken together, the two updates, once implemented, provide regulatory standards for the entire Sacramento-San Joaquin River watershed, from the Oregon border to Fresno.
“It is a consequential effort,” said Eric Oppenheimer, chief deputy director of the State Water Resources Control Board, in a briefing on his agency’s update to the Bay-Delta Plan. “It reflects years of scientific analysis that we’ve undertaken and years of public input.”
Regulation of flows in the Sacramento-San Joaquin River watershed has not been fully updated since 1995. Since then, waterways have been choked with pollutants, algal blooms have proliferated, salmon populations have collapsed and climate change has raised the specter of deeper droughts. Rivers and creeks sometimes run dry, or come close to it, because of the constant pumping.
The Delta, where much of the state’s river water flows before being exported to the Bay Area, southern California and the agricultural lands in between, has borne the brunt.
Getting more water back into the watershed to improve the situation, however, has been a sore point for the scores of municipal and agricultural water agencies that take water from the rivers, creeks and wetlands. A handful of agencies, including the San Francisco Public Utilities Commission, have already sued the state over the 2018 update to the Bay-Delta Plan, saying they’d have to forfeit too much water. Similar wrangling could arise with the new update.
The update for the Sacramento River basin and the Delta offers several alternatives for moving forward. The state water board’s leadership is expected to settle on one option next year. But the main proposal calls for the Sacramento River and its many tributaries as well as the three rivers feeding the Delta from the east (the Mokelumne, Calaveras, and Consumnes) to maintain, on average, 55% of their natural flow, meaning 45% can be taken by water agencies.
Currently, these waterways, on average, run at about 45% of their natural flow, with 55% diverted, according to state data. The proposed change would represent a loss of about 2 million acre feet of water for the water agencies, the equivalent of about five San Francisco Hetch Hetchy Reservoirs.
How this loss would be split up among water agencies will be the subject of future discussion, though it’s likely to be dictated by the state’s water rights system, which prioritizes seniority.
In addition to flow requirements, the update to the Bay-Delta Plan contains a handful of other measures. These include restrictions on how much water can be pumped out of the Delta, flow requirements from the Delta to San Francisco Bay and requisite releases of cold water from reservoirs to accommodate salmon runs.
As an alternative to the water board’s regulation, several water agencies, along with the operators of the state and federal water projects, have proposed a plan of their own. Dubbed the “voluntary agreements,” the plan calls for allowing the agencies to take more water than what the board wants but with the tradeoff of restoring natural habitat for fish and wildlife.
Water agencies have said that, without their alternative, cuts to residential, agricultural and corporate water users may be inevitable.
The water board’s leadership has said it will consider the voluntary agreements.
Conversely, many environmental groups, fishermen and tribal leaders have called on the water board to go further to protect the Sacramento River basin and the Delta. Prior reports by the water board have shown that consistent benefits for fish and wildlife will only come if the rivers and creeks maintain at least 55% of their natural flow. The benefit is far greater if 75% of the flow is maintained, according to the reports.
Whatever pathway is ultimately selected, it may be years before it’s implemented.
The water board has been working on a revised Bay-Delta Plan since 2008, and even the update approved by the board’s leadership in 2018 is still not enforced. The court fight over the 2018 revisions continues, and the board’s leadership, rather than proceed with the new regulation, has agreed to also consider voluntary agreements proposed by the water agencies in the San Joaquin River basin.
Public comment on the Bay-Delta Plan update for the Sacramento River basin and the Delta is open through Dec. 15. The document also serves as the required environmental analysis for the regulation. The water board has scheduled several public hearings on the proposal in the interim.
The separate proposal by the state Department of Water Resources to build a tunnel beneath the Delta to expedite water exports is not mentioned in the summary of the Bay-Delta Plan update. The movement of water through the pipeline, though, would likely be subject to whatever regulation comes out of the plan.
“This is a major milestone, but there’s a lot of work ahead of us,” Oppenheimer said.
Reach Kurtis Alexander: kalexander@sfchronicle.com Twitter: @kurtisalexander
