SONORA -- Residents living downstream from a popular summer lake in Tuolumne County were warned to watch for flash floods on Sunday after the dam that holds back the lake's millions of gallons of water sprung leaks, federal and local authorities said.
The operator of Twain Harte Dam reported hearing loud booms and seeing water flowing through breaks in Twain Harte Dam, the National Weather Service said in issuing a flash flood warning for creek-side neighborhoods located southwest of the town of Twain Harte. The dam sits on Twain Harte Lake, a privately owned, man-made lake built in the late 1920s that is 20-to-25 feet deep.
The Tuolumne County Office of Emergency Services said in a statement that state and local water officials have assessed the dam and "do not believe there is an eminent threat of failure." The dam was opened on Sunday and water drained from the lake at a rate of 2,000 gallons per minute on Sunday afternoon to reduce pressure on the structure, county officials said in the statement.
The process is expected to continue for two days, or until the lake's volume has been reduced below the point where the dam is leaking. The lake was closed until further notice.
Twain Harte Lake Association Board President, Betty Jesperson, whose organization owns and operates the dam, told the Union Democrat in Sonora (http://bit.ly/1tKKwjJ) that the California Department of Water Resources' Division of Dam Safety recently completed a routine inspection.
Engineers and geologists from the division were back at the site on Sunday.