(WFXR) — Appalachian Power wants all recreational water users downstream of Claytor and Leesville dams to be aware of the potential rapid rise in water levels this weekend.

The National Weather Service is calling for high temperatures and storms throughout the weekend beginning on Thursday, June 30, which can cause a sudden rapid rise in water levels, making recreational use dangerous.

Extreme heat calls for an increase in power generation at hydroelectric plants, which can cause water levels to significantly rise in a short period of time and fluctuate. Downstream from the Claytor Dam, water levels can increase by up to two feet in just a matter of minutes, while water levels below the Leesville Dam could increase by as much as eight feet over a seven-hour period.

The Claytor Dam, located on the New River in Pulaski County, is operated by Appalachian Power while the Leesville Dam is part of the Smith Mountian Project, a hydroelectric facility on the Roanoke River.

Those wanting to use the rivers this weekend are encouraged to monitor the Smith Mountian or Claytor Facebook pages for updates.