Amid a severe drought, California regulators on Wednesday advanced what could be the state’s first major new water storage project in years despite warnings it would hasten the extinction of an endangered salmon species while disrupting the cultural traditions of some native tribes.

The plan is to build a new lake in Northern California that, when full, could hold enough water to supply 3 million households for one year. Supporters need about $4 billion to build it. Wednesday’s vote by the California Water Commission means the lake — named Sites Reservoir — is eligible for about $800 million in taxpayer money, or about 20% of the project’s price tag.

Major Milestone for Storage Project

The vote is a major milestone for the reservoir, one of seven water storage projects now eligible to receive public money from a 2014 voter-approved bond. But environmental groups complained it was too early for regulators to say the project was feasible, especially since it hasn’t completed multiple environmental reviews required by state and federal law.

They argue the project would pull even more water from the state’s rivers, which are already so depleted that fish hatcheries must send fish downstream by truck to give them a chance to survive.

“Simply put, we have to stop permitting projects and financing projects that worsen this condition,” said Barry Nelson, a policy consultant with the Golden State Salmon Association.

Reservoirs Water Levels at Historic Lows

But the climate-change-fueled drought gripping the Western United States is so severe that many of California’s 1,500 reservoirs are at historic lows. Things are so bad that, earlier this month, state officials told water agencies they wouldn’t get any water from the reservoirs heading into the new year.

“The Sites Reservoir project is not going to solve all of our problems,” said Jerry Brown, executive director of the Sites Reservoir Authority, and who is not related to the former California governor with the same name. “If we do absolutely nothing, I can guarantee you things will get worse.”

California’s reservoirs are a crucial source of drinking water for the state’s nearly 40 million residents, help maintain necessary flows in rivers for fish, and irrigate California’s robust agricultural industry that grows a third of the country’s vegetables and two-thirds of its fruits and nuts.

Severe droughts have strained the state’s supply and renewed calls for more ways to capture and store water from the state’s major rivers and streams instead of letting it flow to the ocean.

Tribal Groups Oppose Project

But just because California builds a new reservoir does not mean the state will have enough water to fill it. Most major reservoirs are connected to rivers and rely on gravity to fill them with water from snowmelt in the mountains. The Sites Reservoir would not connect to any river. Instead, the project must pump water from the nearby Sacramento River.

The idea is to only take water from the river when it has extra to give, such as during large storms like the one that set a single-day record for rain in Sacramento in October. But some tribal groups say that doesn’t make sense because all water in the rivers has a significant purpose.

“The rivers are barely surviving. They can barely sustain life as it is,” said Margo Robbins, a member of the Yurok Tribe, which relies on salmon for food and ceremonial needs. “I would hope that you would take into consideration the huge detriment that this will be to the salmon and native people.”

California Water Commission chair Teresa Alvarado stressed Wednesday’s vote was not a final decision to fund the project. And Brown, executive director of the Sites Authority, noted the project has changed multiple times based on public comments.

“I think our history shows that we do listen,” he said. “We are open to others’ input and we will take that into consideration and carefully review what is put before us to ensure that what we ultimately decide on is something that’s good for all of California.”