California water board adopts Sacramento River and Delta plan pairing river flows with habitat restoration

California's State Water Resources Control Board adopted amendments to its water quality plan for the San Francisco Bay and the Sacramento-San Joaquin Delta on October 29, according to the board's Bay-Delta page. They set new requirements for the water rights holders that divert water from the Sacramento River, its tributaries, the Delta's eastside tributaries and the Delta itself. Governor Gavin Newsom's office announced the decision on October 30 and called it the first major update to the plan's Sacramento/Delta protections since 1995.

The stakes are large. The Bay-Delta provides drinking and municipal water to nearly 30 million people and irrigation water for 4 million acres of farmland, the board says in its questions and answers on the update. The board describes the ecosystem as being in ecological decline, with fewer native fish, lost habitat, degraded water quality, more invasive species and harmful algal blooms, and it expects climate change to accelerate those effects. The lower San Joaquin River part of the plan was updated separately in 2018.

Two ways to comply

Water users whose rights are listed in the plan can follow a voluntary-agreements pathway, built on the state's Healthy Rivers and Landscapes program. Participants dedicate part of their water rights to river flows, create habitat over an eight-year period, and pay toward water purchases for the environment, restoration projects and a science program. The board says the commitments are enforceable: flows and habitat must be verified through public accounting, restoration projects must meet construction milestones, and participants who fall short can be moved to the other pathway. After eight years, the board will review the pathway and may extend, modify or end it.

All other water rights fall under a regulatory pathway that requires a minimum amount of unimpaired flow, the water that would remain in a river without dams, storage or diversions, to stay in the rivers year-round, with adjustments for wet and dry years. According to the draft resolution before the board, the inflow requirement is 55% of unimpaired flow, which can be adjusted within a range of 45% to 65%. For existing water rights, water supply adjustments allow lower flows in all but the wetter years.

Tribes and algal blooms

The plan designates Tribal Tradition and Culture as a beneficial use of water to be protected in the watershed, which the governor's office described as a first. The board notes that the designation is not a water right and does not allocate a specific amount of water. The plan also expands monitoring of harmful algal blooms across the Delta, including at six hotspots where they regularly form.

An open question

In its responses to comments, published before the vote, the board said it had received letters from the U.S. Bureau of Reclamation and then from Westlands Water District indicating that they would withdraw from the Healthy Rivers and Landscapes program if certain changes were not made to the plan. Some commenters raised concerns that the two might withdraw and had stated an intent to increase water exports afterwards, and urged the board not to adopt the plan on the assumption that they would stay. The board replied that it was not clear whether Reclamation and Westlands would withdraw, and that the plan includes a process for removing water rights from the pathway if that happens.

What happens next

The amendments take effect once California's Office of Administrative Law approves them, and the water quality standards will also go to the U.S. Environmental Protection Agency, according to the draft resolution. The board says it will post the adopted resolution and plan amendments on its website by November 5. After approval, board staff will release a draft implementation method within one year and implementing regulations within two years, and the voluntary pathway is to begin no later than October 1, 2027, the governor's office said.