Center study flags problem dams for fish survival

Long Valley Dam on Crowley Lake, Mono County

 The Center has developed a new tool for identifying dams that are likely depriving fish downstream of the flows they need to stay alive. The project led by Ted Grantham identified 181 California dams in most need of attention to protect fish, particularly native species. 

“It is unpopular in many circles to talk about providing more water for fish during this drought, but to the extent we care about not driving native fish to extinction, we need a strategy to keep our rivers flowing below dams,” Grantham said in an Oct. 22 news release. 

The “high-priority” list includes:

  • Some of the state’s biggest dams: Trinity Dam on the Trinity River, New Melones Dam on the Stanislaus River, Pine Flat on Kings River and Folsom Dam on the American River.
  • Dams on rivers with the greatest richness of native species: Woodbridge Diversion Dam on the Mokelumne River, Nash Dam in Shasta County and three rubber dams on lower Alameda Creek.
  • Dams affecting the greatest number of native species with "sensitive population" status: Keswick and Anderson-Cottonwood dams on the Sacramento River, and Woodbridge and Nash dams.

Grantham, a postdoctoral researcher at the Center during the study, is a research scientist with the U.S. Geological Survey. He developed the dam-screening tool with Peter Moyle, a fish biology professor at UC Davis and Joshua Viers, an ecologist and associate professor at UC Merced.

Photo: Long Valley Dam on Crowley Lake, Mono County is one of 181 California dams UC Davis researchers identified as candidates for increased water flows to protect native fish downstream. Credit: Stephen Volpin