Garmin screen captures from my ride at the hotel showing all three lakes. Today’s time trial was at the bottom of the screen next to the US29 bridge over the Savannah River. Lake Hartwell is the largest and lowest. Lake Keowee is the middle lake both in height and size – its waters cool the Oconee Nuclear Power Plant. The highest lake is Lake Jocassee. This lake is fed by Whitewater Falls and its waters are pumped up the mountain to a storage resevoir to convert nuclear power at off times into hydroelectric power at peak times.