LOS ANGELES— A court has rejected a water agency challenge to state endangered species protections for the Southern California steelhead.

The United Water Conservation District had challenged the California Fish and Game Commission’s decision to list the imperiled fish as endangered. The Los Angeles County Superior Court ruling late last week upholds the protections granted by the state.

“The court recognized the science showing the plight of this struggling fish and upheld the protections needed to stave off extinction,” said Evan Levy, an attorney at the Center for Biological Diversity. “Development, dams and water diversions have threatened this species so deeply that only a handful of spawning southern steelhead have been seen in recent years. Now that these state protections have survived legal challenge, I’m looking forward to a new chapter for these remarkably complex fish.”

The Center, along with California Trout and the Wishtoyo Chumash Foundation, intervened in the lawsuit to uphold steelhead protections.

“The fish is at serious risk of extinction due to habitat destruction from poorly planned development and damaging water infrastructure. The Southern steelhead is a resilient species, but it needs our help,” said Redgie Collins, vice president of legal and government affairs at California Trout. “This listing, backed by rigorous scientific data collection, is one key part of the puzzle needed for recovery.”

For years the Ventura County-based water agency has challenged protections for the fish, suing the state in 2023 when it granted temporary protections for the steelhead and again in 2025 in the most recent lawsuit. The courts ruled against the water district on both occasions. United Water operates multiple dams that prevent steelhead migration upstream to high-quality spawning habitat.

In 2020 an appeals court ruled against United Water for violating the federal Endangered Species Act by diverting river flows at the Vern Freeman Dam and jeopardizing steelhead survival and recovery.

“My inspiration for cultural and ecological restoration began in my youth as I observed steelhead runs through Saticoy,” said Mati Waiya, executive director of the Wishtoyo Chumash Foundation. “This victory for Isha’kowoch is a major step towards the recovery of the very heart of our sacred rivers. We will not stop the fight until this cultural keystone species is fully recovered.”

The species, Oncorhynchus mykiss, is related to salmon and share the same strategy of using both streams and the ocean. Unlike salmon, the species also has a population that spends its entire life in streams, called rainbow trout. This listing protects both steelhead and rainbow trout below dams from Santa Barbara County to the border with Mexico.