That's a lot of water! We had a catastophic flood near here (Yosemite and river below) in 1997. A couple weeks of heavy snow in the mountains followed by a warm tropical rain that melted all the snow. It flooded hundreds of square miles of valley land. In Yosemite the water level was about 12 feet above the valley floor (The river is about 15 feet below valley floor level and usually 50-100 feet wide. The valley is half a mile wide)
