SLO County reservoir must release water to protect endangered fish, appeals court rules

Environmental Defense Center

Operators of Twitchell Dam must release water from the reservoir to protect Southern California steelhead fish and comply with the Endangered Species Act, according to a recent ruling from the Ninth Circuit Court of Appeals.

In 2019, San Luis Obispo Coastkeeper and Los Padres ForestWatch, represented by the Environmental Defense Center, Sycamore Law Inc., and Aqua Terra Aeris Law Group, filed a lawsuit against the dam’s operators, the Bureau of Reclamation and the Santa Maria Valley Water Conservation District. The lawsuit alleged that they are violating the Endangered Species Act by limiting the amount of water flows in the Santa Maria River to “levels that harm the critically imperiled Southern California steelhead population.”

Twitchell Reservoir is located in southern San Luis Obispo County near the border with Santa Barbara County.

According to the Environmental Defense Center, the Southern California steelhead is one of the most endangered fish in the United States.

“Steelhead are a keystone species for our region and an indicator of health in our local waterways,” the Environmental Defense Center said in a news release. “The operation of Twitchell Dam limits the timing and quantity of flows in the mainstem of the Santa Maria River, preventing steelhead from migrating to and from the ocean and upstream spawning habitat. ... Without adequate flows, fish are unable to complete this process and become stranded in the dry river system.”

According to Linda Krop, chief counsel at the Environmental Defense Center, the issue is one that its clients and other environmental groups have been working on for about 20 years.

The agencies operating the dam claimed that their hands were tied, as the 1954 law that authorized construction of the dam allegedly prohibited them from releasing water for fish.

Originally, the district court ruled in favor of the Twitchell Dam operators, but the plaintiffs appealed, and the Ninth Circuit ruled last Friday that operation of the dam must comply with both the law that authorized the dam and the Endangered Species Act.

“The agencies have discretion to operate Twitchell Dam for other purposes besides irrigation, conservation and flood control — including, potentially, adjusting water discharged to support the migration and reproduction of Southern California steelhead,” the Ninth Circuit Court of Appeals said.

The Environmental Defense Center said that the amount of water necessary to protect the steelhead population would be only about 4% of the reservoir’s average annual amount of stored water and that no water would be released in extremely dry years.

“Our lawsuit seeks to bring the Santa Maria Valley Water District out of the 1950s and into the 21st century,” said Gordon Hensley, San Luis Obispo Coastkeeper’s executive director. “Santa Maria can have both steelhead and its water supply with straightforward changes to water management.”

Multiple studies and reports have been prepared over the years to restore the steelhead population, many saying that flows can be modified to protect the Southern California steelhead without affecting the dam’s other uses.

“It’s not just that you’re putting more water into the river system, it’s the timing,” Krop said, adding that flow modifications are made when steelhead are migrating, not year-round.

Krop told Noozhawk that the Environmental Defense Center and its clients now hope to meet with the dam’s operators to negotiate and work together to make a plan for Twitchell Dam to comply with the Endangered Species Act.

Noozhawk staff writer Serena Guentz can be reached at Follow Noozhawk on Twitter: @noozhawk, @NoozhawkNews and @NoozhawkBiz. Connect with Noozhawk on Facebook.