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 and length of . 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 diameter, 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 ; however, the lake is usually kept below to avoid flooding parts of McArthurâÂÂBurney Falls Memorial State Park. The gross storage capacity is and the usable (active) storage is .
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.
Construction was completed in .