SACRAMENTO, Calif. (AP) — President Joe Biden's administration has agreed to investigate how California manages its water after some Native American tribes and environmental groups complained the state's policies are “rooted in white supremacy.”

The U.S. Environmental Protection Agency announced last week it would investigate the California State Water Resources Control Board. The board, whose members are appointed by the governor and confirmed by the state Senate, sets rules for how to use much of the state's water, including 211,000 miles (339,572 kilometers) of rivers and streams.

Federal law requires the board to review those rules every three years. But the board hasn't kept up with that timeline for the San Francisco Bay/Sacramento San Joaquin Delta Estuary. The estuary is one of the largest in the country and is home to threatened species of fish. It also irrigates California's powerful agriculture industry while providing drinking water to 25 million people.

The tribes say the state is relying on outdated rules that have led to overgrowths of toxic algae and cyanobacteria, which prevent the Single Springs Band of Miwok Indians and the Winnemem Wintu Tribe from performing their cultural, religious and subsistence practices. Little Manila Rising, a nonprofit based in Stockton, says the algae blooms “spread like a lime green film across the surface of the water ... giving off a smell of slowly rotting grass” and preventing communities of color from using the waterways to escape the heat during the summer.

California's water is governed by a complex system based on seniority that does not recognize Native American tribes' historic uses of the state's rivers and streams. Attempts to update the water rules usually end up in court, a process that can take a decade or more to resolve. The board has delayed reviewing the rules in part because Gov. Gavin Newsom's administration has been privately negotiating with big water agencies on what the rules should be.

Newsom wants the water agencies to voluntarily agree on those rules to avoid lawsuits. Last year, those negotiations had a breakthrough when some of the state's largest water agencies signed an agreement with state and federal officials. But Native American tribes and other communities of color say they were not included in the negotiations.

The agreements "are an embodiment of the injustice that’s at the core in many respects of our water rights system,” said Stephanie Safdi, an attorney with the Stanford Environmental Law Clinic who is representing the tribes and environmental groups.

The EPA's Office of External Civil Rights Compliance will handle the investigation. Anhthu Hoang, the office's acting director, said the decision to investigate does not mean the state is guilty. Hoang said the office is a “neutral fact finder” and said the board will have 30 days to respond to the allegations in writing.

The board hasn't done that yet. Ailene Voisin, a spokesperson for the board, said the board “will cooperate fully with the investigation and believes US EPA will ultimately conclude the board has acted appropriately.”

Federal law requires the water rules protect certain beneficial uses of that water. The board is considering adding two tribal beneficial uses to these rules: tradition and culture and subsistence fishing. The board plans to release a report on that proposal this year.

“The State Water Board deeply values its partnership with tribes to protect and preserve California's water resources,” Voisin said. “The board's highest water quality planning priority has been restoring native fish species in the Delta watershed, which are central to the lifeways of many tribes.”

Safdi said any resolution of the allegations must include a “quick and timely update” of the rules done through an “open and public and inclusive process that isn't centered on these exclusionary negotiations with water rights holders.” She also said these rules would need to be updated before the state completes major water infrastructure projects, including building a new reservoir and a tunnel to divert water to Southern California.