Environmental Groups Seek Protections for Endangered Steelhead in the Santa Maria River

October 9, 2019

SANTA MARIA, CA – Today, environmental groups filed a lawsuit in federal court seeking water releases from Twitchell Dam to protect endangered Southern California steelhead in the Santa Maria River system. The lawsuit was filed on behalf of San Luis Obispo Coastkeeper and Los Padres ForestWatch by the Environmental Defense Center, Cooper & Lewand-Martin, Inc., and Aqua Terra Aeris Law Group. The case alleges that the Dam’s operators, the Santa Maria Valley Water Conservation District (“the District”) and Bureau of Reclamation (“Reclamation”), are violating the federal Endangered Species Act (“ESA”) by limiting the quantity and timing of flows in the Santa Maria River to levels that harm the critically-imperiled Steelhead population. The case seeks to enhance an important stretch of the Santa Maria River through an improved flow regime that would benefit the watershed, wildlife, and local communities.

Since its construction in the 1950s, Twitchell Dam has been operated to prevent flows from the Santa Maria River to the ocean, thus preventing the endangered fish from migrating both upstream and downstream, a process that is crucial to the species’ life cycle. Southern California steelhead are a form of rainbow trout that spawn in coastal streams in Southern California before migrating to the Pacific Ocean to mature. Without adequate flows, fish are unable to complete this process and get stranded in a dry river system.

“Our lawsuit seeks to bring the Santa Maria Valley Water District out of the 1950s and into the 21st Century. Releasing water for fish migration will have virtually no impact on agricultural or domestic supply–our experts estimate 4% of reservoir water would be affected. Santa Maria can have both steelhead and its water supply with straightforward changes to water management,” said SLO Coastkeeper’s Executive Director, Gordon Hensley.

“Endangered steelhead have nearly disappeared from river systems throughout the central coast of California. Today’s legal action seeks to restore one of our region’s most prolific fisheries while maintaining reliable water supplies for our farms and communities,” said Los Padres ForestWatch Executive Director, Jeff Kuyper.

“We hope today’s lawsuit will quickly bring the operators of Twitchell Dam into compliance with the law so that steelhead, one of the most endangered fish species in the United States, have a shot at survival and recovery,” said Maggie Hall, Staff Attorney for the Environmental Defense Center, which represents Los Padres ForestWatch.

Seventy years ago, the Santa Maria River had the second largest Steelhead run in Santa Barbara County. By some estimates as many as 10,000 fish traveled up the watershed in wet years, with the Sisquoc River in the Los Padres National Forest being the most important spawning tributary within the stream network. However, several large dams have since blocked historic steelhead runs. Now, Southern California steelhead are one of the most endangered fish species in the United States. Steelhead are a keystone species for our region and an indicator of the health of our local waterways.

Twitchell Dam is located on the Cuyama River, the northern tributary to the Santa Maria River, and has been identified as a major obstacle to steelhead passage on the mainstem of the Santa Maria River. Steelhead migrate to and from Sisquoc spawning grounds via the Santa Maria River. However, the operation of Twitchell Dam limits the timing and quantity of flows in the mainstem of the Santa Maria River, preventing steelhead from reaching the Pacific, and ocean-dwelling steelhead from reaching Sisquoc spawning habitat, as the following map depicts:

In 2007, the California Coastkeeper Alliance sued to compel the (then) California Department of Fish and Game to initiate stream flow studies as required by law. The resulting study by Stillwater Sciences recommended an improved flow regime at Twitchell Dam, yet the Water District and Reclamation have failed to implement the recommendations. Today’s lawsuit aims to implement the Stillwater Study’s recommendations to improve the flow regimes at Twitchell Dam and prevent continued harm to the endangered steelhead. The amount of water necessary to provide flows of appropriate timing and magnitude for Steelhead would constitute only roughly 4% of the reservoir’s average annual amount of stored water.

The groups sent the District and Reclamation a “Notice Letter” in February 2019 documenting the harm that current operations at Twitchell Dam cause to steelhead. Because the Dam operators have still not modified operations sufficient to protect the species, the groups filed the present lawsuit.

Today’s lawsuit complements a separate legal action filed by the two organizations in 2017. That suit, which is pending in state court, is based on longstanding California law that requires dam operators to provide adequate streamflow to sustain healthy fish populations.


San Luis Obispo Coastkeeper is a non-profit public benefit corporation whose mission is to

protect and enhance the water quality of the Central Coast area coastline, and its tributaries, including the Santa Maria River, for the benefit of its ecosystems and the surrounding human communities.

Los Padres ForestWatch is a local, independent 501(c)(3) organization working to protect wildlife, wilderness, and watersheds throughout the Los Padres National Forest along California’s Central Coast.

The Environmental Defense Center, a non-profit law firm, protects and enhances the local environment through education, advocacy, and legal action and works primarily within Santa Barbara, Ventura, and San Luis Obispo counties. Since 1977, EDC has empowered community based organizations to advance environmental protection. EDC’s focus areas include protection of the Santa Barbara Channel, ensuring clean water, preserving open space and wildlife, and addressing climate and energy. Learn more about EDC at www.EnvironmentalDefenseCenter.org

Join our Mailing List