The U.S. Army Corps of Engineers, who manage Lake Lanier and Buford Dam, typically release water weekday afternoons, but not always. Four warning sirens are placed between Buford Dam and Ga. 20. During a release, the Chattahoochee can rise as much as 11 feet in minutes. With water temperatures as cold as 47 degrees, hypothermia can prevent efforts to swim to shore.
According to the city, “the Johns Creek Fire Department Swift Water Rescue Team responds several times a month to emergency calls to rescue people from the frigid, rushing water of the river.”