Sonoma County has approved a $4 million contract for the second phase of what could become a sweeping, $50 million environmental restoration project along Dry Creek west of Healdsburg.
The construction, scheduled for this summer, will complete the first of six miles of planned work along the creek, which serves as the artery for drinking water stored in Lake Sonoma to the north. Using the creek as an aqueduct to meet the needs of 600,000 residential and business customers in Sonoma and Marin counties has damaged the spawning grounds for delicate populations of steelhead trout and coho salmon, federal officials have concluded.
“The creek right now is a vibrant ecosystem,” said David Manning, environmental resources coordinator for the Sonoma County Water Agency, “but it needs to be changed, in some places subtly and in some places dramatically” to accommodate the needs of the fish that once spawned there in great numbers.
The Sonoma County Board of Supervisors, which also heads the separate Water Agency, approved the contract unanimously last week.
Federal officials have ordered the agency, and the U.S. Army Corps of Engineers, which operates Warm Springs Dam at Lake Sonoma, to restore fish habitat by 2020. Because many details of the project remain uncertain, the Water Agency says, it is hard to tell how much the full project might cost or how the burden might be distributed among ratepayers and the state and federal governments. Estimates of the total cost run as high as $50 million.
That price, however, is cheaper than the alternative, Manning said, which would be to build a new underground pipeline to divert the drinking water flow out of the stream, allowing the creek to return to a more leisurely natural flow rate that is better suited to fish spawning. Such a pipeline could cost up to $150 million.
“That is a place we really do not want to go,” Supervisors Chairman David Rabbitt said.