Bay Area environmental watchdog San Francisco Baykeeper has filed suit against the Santa Clara Valley Water District for allegedly violating the California Constitution and the Fish and Game Code through its water management practices.

“Valley Water has failed for years to manage its waters in a manner that protects fish and wildlife,” Baykeeper in a statement Tuesday.

According to Baykeeper, Valley Water is responsible for area creeks and rivers that support salmon, steelhead, longfin, smelt, riffle sculpin, rainbow trout and “many other public trust resources.”

Baykeeper’s lawsuit alleges that Valley Water “routinely” causes temperatures in the creeks and rivers it manages to be too warm and at flow rates that are too low, something Baykeeper says is “fatal to fish.”

“This lawsuit jeopardizes the work we’ve already done with our partners to improve habitats in our creeks and waterways. … It could also cause delays to the Anderson Dam Seismic Retrofit Project.”

Santa Clara Valley Water District statement

Valley Water released a statement about the suit, saying that it “smacks environmental justice in the face” by increasing project costs, which “directy impacts” water rates.

“This lawsuit jeopardizes the work we’ve already done with our partners to improve habitats in our creeks and waterways,” said the agency in a statement. “Because the suit seeks explicitly to mandate the management of Coyote Creek, which runs from Anderson Dam to San Francisco Bay, it could also cause delays to the Anderson Dam Seismic Retrofit Project.”

Valley Water asserts that any delays may threaten water supplies during a historic drought.

The agency didn’t directly respond to Baykeeper’s allegations of flow and temperature issues in waterways, but said it has “worked tirelessly and diligently” to adopt science-based policies to manage and protect Santa Clara County’s watershed and aquatic ecosystems. Valley Water said it employs a “careful balancing act” between providing water to 2 million residents and businesses while acting as a guardian of the creek and stream environments.

Baykeeper attorney Ben Eichenberg called for “immediate” action from Valley Water.

“Valley Water’s legal obligations are clear: They must take action immediately to prevent the destruction of fish populations in the rivers and creeks they manage,” he said. “This is what the law demands, it’s good for the Bay Area, and it’s long overdue.”