Saddlebag Lake, located just east of Yosemite National Park’s eastern Tioga Pass entrance, is being drained down fairly rapidly and some rumors have been floating around as to the reason. The lake is part of Southern California Edison’s (SCE) hydroelectric project located on Lee Vining creek utilized by Southern California Edison to produce small-scale hydro-power.
SCE issued the following statement:
Southern California Edison routinely inspects all of its dams for safety. At Saddlebag Lake, some leakage happens through existing naturally occurring cracks in the bedrock under the dam. In the fall of 2017, an increase in leakage was observed. SCE Dam and Public Safety engineers determined the increase was caused by cracks in the bedrock that previously were sealed. SCE will use pressurized grout to reseal the cracks. The integrity and safety of the dam has not been affected.
Saddlebag Dam, at 10,090′ elevation and the highest lake you can drive to in California, was built in 1921 to enlarge an existing alpine lake for hydropower generation purposes. The dam was raised and a spillway was added in 1925. Back in 2011, the lake was lowered to upgrade the dam face at Saddlebag Lake Reservoir, installing of a new geomembrane liner to protect the dam face from current and future leaks. The liner was expected to extend the life span of the dam by up to thirty years. By the summer of 2017, the lake had filled up and was flowing over the spillway – possibly a first for the dam.
The Lee Vining Creek System consists of Saddlebag, Ellery, and Tioga Lakes, along with the Poole Powerhouse along the upper reaches of Lee Vining Creek, and a substation in the town of Lee Vining. Energy has been generated by the long fall of the water from these lakes down several thousand feet of penstocks has kept the Poole Power Plant since 1923.