Wishon Dam
| Company type | Public utility |
|---|---|
| Industry | Energy |
| Founded | 1905 |
| Headquarters | San Francisco , United States |
| Products | Electricity generation, transmission, and distribution |
| Website | www |
Wishon Dam (National Identification # CA00411) is an embankment dam composed of earth and rockfill, situated in Fresno County, California within the Sierra National Forest of the Sierra Nevada mountain range. Built in 1958 by Pacific Gas and Electric Company (PG&E), the dam measures high and extends along its crest. It impounds the North Fork Kings River, creating Wishon Reservoir.
Together with the adjacent Courtright Dam and additional support infrastructure, Wishon Dam forms part of PG&E’s Haas-Kings River Project. The Courtright Reservoir acts as the upper basin for the 1,212 MW Helms Pumped Storage Facility, while Wishon Reservoir serves as the lower basin. During periods of peak electricity demand—when market prices peak—water is released from Courtright through the Helms Power Plant to generate electricity before collecting in Wishon Reservoir. When demand decreases and prices fall, water is pumped back uphill from Wishon to Courtright using reversible turbine technology. The Helms Powerhouse is located approximately 1,000 feet beneath the surface in granite near Wishon Lake, sharing design characteristics with Southern California Edison’s Eastwood Powerhouse.
The maximum storage capacity of Wishon Reservoir is 128,606 acre-feet. PG&E promotes recreational use of the reservoir, offering opportunities such as fishing for German brown trout, rainbow trout, and Eastern Brook trout, along with boating, camping, and hiking activities. On the reservoir's southern shore, Lily Pad Campground provides 15 campsites managed by PG&E. Prior to the dam’s construction, the area now flooded by the reservoir was known as Coolidge Meadows.