February 1, 2011 > Calaveras Dam project revised
Calaveras Dam project revised
Conservation groups win flow releases and changes in dam operations to improve habitat for steelhead trout
Submitted By Jeff Miller, Alameda Creek Alliance
The final Environmental Impact Report for the San Francisco Public Utilities Commission project to replace Calaveras Dam in the upper Alameda Creek watershed was released earlier this month and includes revisions to the project to benefit restoration of threatened steelhead trout such as changes to dam operations, constructing a fish ladder and fish screens on a diversion dam, initiating a habitat management plan and providing more water flow in Alameda Creek.
"The revised Calaveras Dam replacement project will significantly advance the restoration of steelhead trout to Alameda Creek through water releases, constraints on water diversions, fish passage projects and other habitat improvements," said Jeff Miller, Director of the Alameda Creek Alliance. "San Francisco should be commended for moving toward more sustainable watershed management and we look forward to working with the SFPUC to restore habitat conditions in upper Alameda Creek."
"However, the SFPUC continues to pursue a Sunol Valley water diversion project that would recapture an unspecified amount of stream flow releases from upstream dams and this could interfere with steelhead migration," said Miller. "Why threaten the benefits of restored stream flows by taking the water back?"
The SFPUC has committed to providing year-round water releases into Alameda Creek from Calaveras Reservoir ranging from 5 to 12 cubic feet per second, depending on the time of year and water-year type (wet, normal or dry). Particularly important will be cold-water flow releases during summer months to improve water quality and rearing conditions for trout. The Commission will modify operation of a 32-foot diversion dam in upper Alameda Creek, reducing its water diversion capacity by more than 40 percent, closing the diversion gates for more of the year to allow unimpaired natural flow to continue downstream, and ensuring minimum flows of 30 cubic feet per second past the dam during winter and spring.
SFPUC will also construct a fish ladder around the diversion dam and investigate fish passage improvements downstream to help adult steelhead migrate into the headwaters of Alameda Creek, the best trout habitat in the watershed below major dams. The Commission will install a fish screen on the diversion dam and improve screens in the reservoir to prevent small juvenile trout from being diverted or trapped during water operations. The SFPUC also announced a management plan to monitor stream flows and improve habitat conditions, with a stated goal of restoring a self-sustaining steelhead population in the watershed.
Alameda Creek is becoming an urban stream success story due to ongoing restoration efforts but it took years of advocacy by conservation groups and tough permit requirements by state and federal regulatory agencies to make the Calaveras Dam project beneficial to steelhead. Alameda Creek is an 'anchor watershed' considered regionally significant for restoration of steelhead to the entire Bay Area. Since central coast steelhead were listed as threatened under the Endangered Species Act in 1997, numerous agencies have pursued restoration projects to allow migratory fish from the Bay to reach spawning habitat in the upper creek. Downstream of San Francisco's dams, 11 fish passage projects at smaller barriers in the creek have been completed since 2001.
Several more major fish ladder and dam removal projects are scheduled for completion over the next few years, including a fish ladder in Fremont past the "BART weir" and an Alameda County Water District rubber dam in the lower creek. These projects will allow steelhead to reach approximately 20 miles of spawning and rearing habitat in the watershed for the first time in nearly half a century.
"All eyes are now on the progress of the planned fish ladder at the BART weir in the lower creek, which, when completed, will allow migratory fish to finally return to upper Alameda Creek," said Miller.
For more information, visit www.AlamedaCreek.org