Environmental groups filed a lawsuit on April 26 seeking water releases from Twitchell Dam, aiming to adjust the timing of flows from the Santa Maria River to the ocean to open a migratory path for the endangered Southern California steelhead trout.
The plaintiffs, San Luis Obispo Coastkeeper and Los Padres ForestWatch, claim that specific timing of the Santa Maria River flow is necessary to prevent the steelhead from going extinct, according to a press release from the groups.
They’re suing the Santa Maria Valley Water Conservation District in state court, citing part of the California Fish and Game Code that states, “The owner of any dam shall allow sufficient water at all times to pass through a fishway, or in the absence of a fishway, allow sufficient water to pass over, around, or through the dam to keep in good condition any fish that may be planted or exist below the dam.”
The Sun reached out to the water conservation district for comment but did not receive a response as of press time.
The release said that 70 years ago, the Santa Maria River provided the second largest steelhead run in Santa Barbara County, hosting the migration of thousands of fish to and from spawning grounds in the Sisquoc River in Los Padres National Forest. But since the Twitchell Dam’s construction in the 1950s, the water conservation district has trapped streamflow during the winter and spring to replenish groundwater supplies.
Because winter and spring are the times of year when steelhead would normally migrate upstream, Coastkeeper and ForestWatch claim the water conservation district’s dam operations have limited the steelheads’ migration and stranded them in a drying channel.
“Endangered steelhead have nearly disappeared from river systems throughout the Central Coast,” ForestWatch Executive Director Jeff Kuyper said in the release. “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.”
The plaintiffs are demanding that the water conservation district time the water releases from Twitchell Dam for when the Sisquoc River’s stream flow is between 350 and 550 cubic feet per second for two consecutive days, which would ensure water flows downstream into the Santa Maria River so fish can safely pass through, according to a statement from Coastkeeper and ForestWatch. The releases could stop once water levels become impassable or when at least 12 days of steelhead-passable conditions have been achieved in the current water year.
Overall, the supplementary releases from Twitchell Dam would total between 1,020 and 1,500 acre-feet per year, the statement said. The releases shouldn’t affect groundwater supply in drought years.
“The lawsuit is not seeking the release of more water from Twitchell Dam,” the groups’ statement said. “Rather, it seeks to adjust the timing of water releases. Water would only be released for steelhead during relatively wet years, when some stream flow is present in the Santa Maria River.”
Because the Santa Maria River runs low during drought years, the statement said, supplemental releases wouldn’t take place during those times.
