Crews work to fortify the earthen dam at Little Washoe Lake on Monday afternoon, which is in danger of a potential breaching.
Emergency crews from the Division of Water Resources are fighting to plug a leak in the 100-year-old Washoe Dam.
State Engineer Jason King said a routine inspection today discovered the earth and rock dam is leaking at its base beneath the spillway from Little Washoe Lake.
He said that puts the dam in danger of failing, which would send a torrent of water down Steamboat Creek that could flood downstream communities from Pleasant Valley all the way to Pawnee Dam, another old earthen structure.
King said the seepage means the old dam has problems but doesn’t necessarily mean it’s going to fail.
“I think we’re in front of it and think we’re going to be OK,” said King.
He said heavy equipment was called to the scene to dump earth and rock into the small whirlpool on the reservoir side of the dam. The goal, he said, is to “plug it from the upstream side.”
The dam holds back the waters of Little Washoe Lake and, by extension, Washoe Lake itself at the northern end of Washoe Valley. Other than evaporation, Steamboat Creek is Washoe Lake’s only outlet.
Steamboat Creek runs all the way north to south Reno and east into Sparks, eventually flowing into the Truckee River.
“We’re actively managing a partial failing of the Washoe Lake Dam,” King said. “Currently the dam is not breached and repairs are under way.”
He said he doesn’t know what would happen if a large amount of water was released.
The dam is managed by a company tasked with providing water to downstream water rights holders but owned by the pioneer Damonte family.