| Pit-3 Dam | |
| Name Official: | Pit Number Three Dam |
| Location Map: | California |
| Location Map Size: | 230px |
| Location Map Caption: | Location of Pit-3 Dam in California |
| Coordinates: | 41.0217°N -121.6758°W |
| Country: | United States |
| Location: | Shasta County, California |
| Owner: | Pacific Gas and Electric Company[1] |
| Dam Length: | 494feet |
| Dam Height: | 130feet |
| Dam Width Crest: | 30feet |
| Dam Width Base: | 110feet |
| Dam Crosses: | Pit River |
| Res Name: | Lake Britton |
| Res Capacity Total: | 41877acre feet |
| Res Catchment: | 4700sqmi |
| Res Surface: | 1265acres[2] |
| Plant Hydraulic Head: | 600feet |
| Plant Capacity: | 69.9 MW |
| Plant Annual Gen: | 333,606,000 KWh (2001–2012)[3] |
| Plant Type: | R |
Pit-3 Dam (also known as Pit Number Three Dam and Dam Number Three) is a hydroelectric dam on the Pit River in northern California in the United States. It forms Lake Britton, and is owned by the Pacific Gas and Electric Company (PG&E).
Pit 3 is a curved concrete gravity dam with a height of 130feet and length of 494feet. The dam has a gated spillway with three steel gates and three inflatable rubber gates. An intake structure at the dam diverts water into a 19feet diameter, 21203feet long tunnel that connects to the Pit 3 hydroelectric plant. There are three 23.3 MW generators, for a total capacity of 69.9 MW.
Lake Britton, formerly known as Pit 3 Reservoir, has a maximum water level of 2737.5feet; however, the lake is usually kept below 2736.5feet to avoid flooding parts of McArthur–Burney Falls Memorial State Park. The gross storage capacity is 41877acre feet and the usable (active) storage is 14443acre feet.
The lake level changes on a weekly basis with greater drawdowns during the weekdays for power generation, and refilling on the weekends. In addition to generating power at the Pit 3 hydroelectric station, the reservoir also helps regulate water flowing through the Pit 4 and Pit 5 stations downstream.
The dam is the place where Pacific Crest Trail crosses the Pit River.[4]
Construction was completed in .[5]