California is moving ahead with a sweeping plan to change how water is managed across the Sacramento-San Joaquin Delta as critics warn the proposal could harm rivers and fish while failing to secure water supplies.

The State Water Resources Control Board recently released its August 2026 draft update to the Bay-Delta Plan, which would establish new water-quality protections and rules for the Delta and its tributaries.

The watershed is a critical part of California’s water system, supplying water to nearly 30 million people and supporting about 4 million acres of farmland.

The board says the proposal is designed to balance those demands while improving conditions for fish, wildlife and tribal communities.

“This is California’s opportunity to manage the Bay-Delta for the twenty-first century,” State Water Board Executive Director Eric Oppenheimer said in a statement. “We can protect rivers, fish, wildlife and tribal cultural uses while building greater resilience and security for communities, farms and the state’s economy.”

“We believe we need a new approach,” he told the LA Times. “We need a plan that balances ecosystem needs and human water demands.”

But environmental and fishing advocates have argued that voluntary agreements with water users are not enough to reverse decades of declining river flows and fish populations.

Gary Bobker, program director of Friends of the River, called the approach “a plan that is doomed to fail.”

At the center of the proposal is a requirement for a 55% unimpaired-flow target on key Sacramento River and Delta tributaries, measured as a seven-day running average.

The plan also establishes a 40% unimpaired-flow requirement for the lower San Joaquin River from February through June, with an adaptive range of 30% to 50%.

The rules would set reservoir storage targets designed to maintain cold water needed by salmon for spawning, rearing and migration.

Water users would have two main ways to comply: follow the standard regulatory pathway or participate in the Healthy Rivers and Landscapes program, an eight-year voluntary pathway combining additional river flows, habitat restoration and water purchases.

The state says the program would help facilitate $2.9 billion in restoration and related projects, including more than 27,000 acres of aquatic habitat restoration.

The plan would also recognize “Tribal Tradition and Culture” as a protected beneficial use of water for the first time, reflecting tribal connections to rivers, fish and cultural practices.

If water users fail to meet requirements, the state could use its regulatory authority to curtail water rights based on priority, with exceptions for basic health and safety needs, emergency firefighting and certain wildlife refuges.

The state also plans to establish a monitoring program tracking river conditions, fish populations, water flows and harmful algal blooms. Officials would hold annual public meetings and conduct formal reviews every three years to determine whether the plan is working.

Critics have questioned whether voluntary agreements, habitat projects and flow requirements will actually produce meaningful improvements.

“We are starving the Bay-Delta estuary now,” Bobker told the Times, arguing that conditions must change to preserve the ecosystem and its benefits.

The State Water Board is accepting public comments through Sept. 18 and plans to consider adoption of the updated Bay-Delta Plan during a public hearing Oct. 28-29.

The debate comes after decades of conflict over how much water should remain in California’s rivers for the environment and how much should be available for farms, cities and other users.