After heavy rain Sunday, April 12, and Monday, April 13, Smith Mountain Lake’s water level increased past its full amount at 795 feet, going over the dam’s spillways.
The Smith Mountain Project Facebook page posted on the morning of Tuesday, April 14, that they expected the lake to be back to their normal levels by Wednesday morning.
According to Appalachian Power, operator of the Smith Mountain Project hydroelectric facility in southwest Virginia, Smith Mountain Lake reached its full pond level of 795 feet on Monday.
The project’s lower reservoir, Leesville Lake, was below its full pond level of 613 feet.
For the forebay actual and tailwater numbers on Thursday, Smith Mountain Lake was at 794.61 and 605.98 feet, respectively.
According to aep.com, “the forebay and tailwater numbers show the feet above sea level of the water levels immediately upstream and downstream from our plants,” and the “tailwater flow is the hourly average of the river flow just downstream of the plants, measured in cubic feet per second.”
Appalachian Power said that flow levels above and below the project were high and cautioned residents and boaters to stay aware of debris that the heavy rains may have caused.
The lakes being affected by water levels above full pond is rare, but an increase of only inches could make walking docks unsafe, cause unsecure water craft and floating docks to float away into navigation channels and wash loose items from the shore.
Smith Mountain Project is a 636-megawatt pumped storage hydroelectric facility on the Roanoke River that utilizes an upper reservoir (Smith Mountain Lake) and a lower reservoir (Leesville Lake).
Water stored in Smith Mountain Lake first passes through turbine-generators in the powerhouse to produce electricity and is discharged into Leesville Lake. From there some water is released through the Leesville Dam or pumped back into Smith Mountain.