The National Weather Service is reporting major flood stage for the Tallulah River at Tugalo Dam for the next 48 hours.
That means all gates on the dam are open and flooding downstream will cause flooding below Yonah Dam, creating a high-water event.
There is the potential for hikers, boaters and fishermen to be swept away if they are in or near the water.
The advisory urges people to refrain from boating, hiking or fishing on either Tugalo or Yonah Lake.
Officials say there is a moderate threat to life and property over the next 48 hours.
The advisory impacts people in Rabun, Habersham and Stephens counties in Georgia as well as Oconee County, S.C.
