Results of a recent study identified 181 dams in California most in need of attention to protect fish, particularly native species.
According to research performed at the UC Davis Center for Watershed Sciences, these dams were revealed using a new method developed at the center to identify dams that are likely depriving fish downstream of the flows they need to stay alive.
Writing in the California Water Blog, Ted Grantham (research scientist with the U.S. Geological Survey) and Peter Moyle (professor of fish biology at UC Davis) say, “This drought year … California water regulators have given away to cities and farms some river flows critical to fish and wildlife.” The “beneficial use of water” section of the California constitution and other legal backstops are intended to prevent loss of fish through the operation of dams. For example, Section 5937 of California Fish and game Code requires dam owners to release enough flows “at all times” to keep fish “in good condition,” but many dam owners have not met this requirement and the state has not enforced the rule, Grantham and Moyle say.
“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,” says Grantham.
The researchers asked the question: If Section 5937 were more broadly applied to improve fish flows, which dams should get the focus of attention? The high-priority list of dams, identified using this new method, includes:
— Trinity Dam (which impounds water for a 140-MW powerhouse) on the Trinity River;
— New Melones Dam (which impounds water for a 300-MW powerhouse) on the Stanislaus River;
— Pine Flat Dam (which impounds water for a 165-MW powerhouse) on the Kings River;
— Folsom Dam (which impounds water for a 198.72-MW powerhouse) on the American River;
— Woodbridge Diversion Dam on the Mokelumne River;
— Three rubber dams on lower Alameda Creek;
— Keswick Dam (which impounds water for a 117-MW powerhouse) on the Sacramento River; and
— Anderson-Cottonwood Dam on the Sacramento River.
Writing in the blog, the authors say, “A recent study estimated that more than 80 percent of California’s native fish are at risk of extinction if present trends continue.” They conclude, “Strategic implementation of Section 5937 could provide reasonable protections of California’s dammed rivers and streams.”