The battle over whether California should build a $20-billion water tunnel in the Sacramento-San Joaquin River Delta is escalating, with Gov. Gavin Newsom pushing to lay the groundwork for the project before his term expires and state water regulators considering whether to grant a key authorization.
The State Water Resources Control Board has begun holding a series of hearings on a petition by the Newsom administration to amend water rights permits so that flows could be diverted from new points on the Sacramento River where the intakes of the 45-mile tunnel would be built.
The process has grown tense in recent weeks, as the Newsom administration and water agencies have pushed back against how the board’s officials are handling parts of the process, and as opponents have urged the board not to bend to political pressure.
Speaking at a virtual hearing Thursday, state Department of Water Resources general counsel Ann Carroll presented the Newsom administration’s case for the tunnel, calling it one of California’s “most important climate adaptation projects.”
“Changing precipitation patterns are leading to more rain, less snow and a limited ability to capture and move water,” Carroll said. “The ability to capture high flows when available is critical to adapting to a changing climate.”
Supporters of the plan, called the Delta Conveyance Project, say the state urgently needs to build new infrastructure in the Delta to protect the water supply in the face of climate change and earthquake risks. Large Southern California water agencies are supporting the project by providing initial funding for planning work.
Opponents, including Northern California agencies, environmental advocates and Native tribes, argue the project is an expensive boondoggle that would harm the environment, fish species and communities, and that the state should pursue other alternatives. They have argued that the main beneficiaries would be development interests in Southern California and agricultural landowners in the southern San Joaquin Valley.
The tunnel would create a second route to transport water to the state’s pumping facilities on the south side of the Delta, where supplies enter the aqueducts of the State Water Project and are delivered to 27 million people and 750,000 acres of farmland.
Newsom made his pitch for the project in a Feb. 18 letter to the state water board, saying “California’s prosperity depends upon it.” He noted that the last two California governors, Jerry Brown and Arnold Schwarzenegger, also supported earlier iterations of the concept to modernize the state’s water system.
Six years ago, Newsom announced he was downsizing Brown’s proposal for a twin tunnel and instead called for a redesigned single tunnel. Now, he said, the current proposal “has been thoughtfully refined to protect the environment, fisheries, ecosystems, water quality and water supply.”
During a state Senate subcommittee hearing Thursday, Department of Water Resources Director Karla Nemeth responded to critical questions from legislators about the costs and environmental effects of the project.
Nemeth described the existing system as an asset that is “starting to really underperform,” and said the tunnel, if it existed now, could have captured more water during storms over the last three years. State officials have estimated that climate change could reduce average supplies available from the State Water Project by up to 23% over the next 20 years, and Nemeth said building the tunnel would ameliorate the decline and restore about 16% of that lost supply.
The Newsom administration’s package of petitions is being considered by Nicole Kuenzi, who leads the state water board’s independent Administrative Hearings Office. State officials have argued against some of Kuenzi’s initial rulings, which have included requesting historical data on how much water was previously diverted under the rights, and considering questions such as whether approving the project would be in the public interest.
Nemeth issued a statement directed to Kuenzi on March 24, saying the question of whether the use of water is in the public interest does not apply, and would only apply if the petition were for a new water right.
“Importantly, the Legislature already has determined that the State Water Project is in the public interest, and Governor Newsom has made clear that this project is of the utmost importance to current and future Californians,” Nemeth wrote. “Unfortunately, the Administrative Hearings Office has conflated the petitions and fundamentally enlarged the scope of this hearing.”
Saying that could lead to costly delays, Nemeth urged Kuenzi to “structure a hearing process that results in a final decision by the full State Water Board before late 2026” — shortly before the end of Newsom’s second term.
Opponents of the project — including environmental groups, tribes and representatives of several Northern California counties that rely on water from the Delta — responded in a letter urging the board to make clear that political interference won’t sway the outcome.
“The Board must insist on its own independence and the independence of its hearing officers,” they wrote. “The loss of this independence, or even the appearance that it is lost, would undermine the credibility of the Board and its mission.”
Osha Meserve, a lawyer who signed the letter on behalf of Contra Costa and Solano counties and other local agencies, said the board’s integrity is at stake, as well as public trust and confidence in the process.
There are at least seven court cases challenging the project pending in courts or on appeal, and Meserve is involved in most of them. She said building the tunnel “would destroy farms, rural communities and the environment, all at unbelievably expensive cost.”
Opponents say the tunnel would threaten native fish species that are already suffering major population declines. They’ve said the state should instead bolster water supplies by upgrading aging levees in the Delta and investing more in recycling wastewater, capturing stormwater locally and making other improvements to use water more efficiently.
As part of the campaign against the project, the nonprofit group Restore the Delta last month released the results of a statewide survey of 649 registered voters showing that, when initially asked about the project, 46% said they were in favor and 24% were opposed, with 29% unsure. But after those same people were presented with arguments on both sides of the debate, those opposed increased to 58%, while 34% were in favor and 8% were undecided.
The February poll, which reported an error margin of 4 percentage points, also found that 62% said they would prefer investing in “developing local water supplies to ensure California communities are more resilient and better prepared to tackle threats from fires, droughts, and floods.”
“The state must abandon this outdated project that they have kept alive for decades,” said Barbara Barrigan-Parrilla, executive director of Restore the Delta. “People reject expensive megaprojects like the Delta tunnel.”
However, many leaders of Southern California’s large water agencies have been supporting the project, viewing it as a viable option to improve the reliability of supplies from Northern California.
In December, the board of the Metropolitan Water District of Southern California voted to spend $141.6 million for a large share of the preliminary planning work. The district, which delivers water for 19 million people, isn’t expected to decide whether to invest in building the tunnel until 2027.
Managers of the MWD and other agencies that are members of the State Water Contractors have said they disagree with some of the hearing officer’s recent rulings, which they fear could jeopardize the schedule of hearings in the coming months and lead to costly delays.
In a letter to the board, 19 water managers wrote: “For each day of delay in constructing this critical project, the cost of the project increases by over $1 million.”
The current hearings aren’t the only related issue before the board. In January, the Newsom administration also filed separate petitions seeking to extend the time of the water rights permits to 2085.
Chandra Chilmakuri, the State Water Contractors’ assistant general manager for water policy, said the time extension is a different matter and should be handled separately. If it were considered as part of the current process, he said, that could further delay approval.
He said leaders of water agencies hope the board will reach a decision on amending the water rights permits as soon as possible.
“It’s very important to keep the schedule,” Chilmakuri said.
The state’s plans call for starting construction in late 2029 and completing the tunnel in 2042.
