Pit 5 Dam
Dam in Shasta County, California
From Wikipedia, the free encyclopedia
Pit 5 Dam is a run-of-the-river hydroelectric dam on the Pit River in Shasta County, northeastern California, about 2 miles (3.2 km) south of Big Bend. It is part of the Pit 3-4-5 hydroelectric project owned by Pacific Gas & Electric Company.[4]
| Pit 5 Dam | |
|---|---|
  Pit 5 Dam Location of Pit 5 Dam in California | |
| Country | United States |
| Location | Shasta County, California |
| Coordinates | 40°59′30″N 121°52′16″W[1] |
| Purpose | Hydroelectric |
| Opening date | 1944 |
| Owner | PG&E |
| Dam and spillways | |
| Impounds | Pit River |
| Height (foundation) | 58 ft (18 m)[2] |
| Length | 340 ft (100 m)[2] |
| Reservoir | |
| Creates | Pit 5 Reservoir |
| Total capacity | 330 acre⋅ft (410,000 m3)[2] |
| Pit 5 Powerhouse | |
| Installed capacity | 160 MW[3] |
| Annual generation | 781,328,000 KWh (2001–2012)[3] |
Specifications
The concrete gravity diversion dam is 58 feet (18 m) high and 340 feet (100 m) long.[2] It has a gated spillway controlled by four 50 ft × 26.3 ft (15.2 m × 8.0 m) steel wheel gates, and a 30 in (76 cm) diameter river outlet for regular releases. An intake structure diverts water into a 5,109-foot (1,557 m) long penstock to the Pit 5 Tunnel forebay reservoir, from which a second 23,149-foot (7,056 m) tunnel connects to the Pit 5 power station. There are four 40 MW generating units, each fed by a 1,380-foot (420 m)-long penstock.[5]
History
The dam and power station were authorized in 1942 and constructed as a wartime project, and the first power was generated on April 29, 1944.[6] Construction of the dam and power station dewatered a stretch of the Pit River known as the "Big Bend". When the projects were relicensed in 2007, a minimum 250 cu ft/s (7.1 m3/s) release[5] into the river was established, to provide recreation benefits such as boating and fishing, and to improve riparian habitat.[7]