The Kaweah River: Hydroelectric Pioneer and the Flood of Nineteen Fifty Five
Near Three Rivers, California
The Kaweah River that runs through Three Rivers has powered generators and flooded towns in equal measure. The first chapter of the hydroelectric story began in eighteen ninety nine, when the Mount Whitney Power Company opened a generating plant called Kaweah Number One on June twenty ninth of that year. The plant diverted water from the East Fork of the Kaweah through a long pipe to a small powerhouse, and the electricity it produced was transmitted to the valley city of Visalia, more than forty miles away.
At the time of its opening, that transmission distance was the longest achieved for electrical power anywhere in the world. The company built two more plants on the Kaweah in the following decade, and Southern California Edison eventually took over the entire system. The river gives back what it takes.
In December of nineteen fifty five, an extraordinary rainstorm sent floodwaters through the Kaweah canyon that were described as a once-in-a-hundred-years event, with peak flows estimated at close to one hundred thousand cubic feet per second. Bridges and homes were destroyed. Sections of Three Rivers were marooned.
In one remarkable episode, giant sequoia logs swept down from Giant Forest during the flood. The Army Corps of Engineers responded by building Terminus Dam, a two-hundred-fifty-five-foot earthfill structure completed in nineteen sixty two, creating Lake Kaweah upstream of Three Rivers. In two thousand four, six fuse gates were added to the dam, raising the lake's storage capacity and providing additional flood protection for the valley below.
