| Lucky Peak Dam | |
|---|---|
Lucky Peak Dam |
|
| Location | Ada Co., Idaho, United States |
| Coordinates | [1] |
| Construction began | 1949 |
| Opening date | 1955[2] |
| Construction cost | $19 million (1955) |
| Dam and spillways | |
| Height | 340 feet (100 m)[2] |
| Length | 2,340 feet (713 m)[2] |
| Impounds | Boise River |
| Reservoir | |
| Creates | Lucky Peak Lake |
| Capacity | 307,000 acre feet (0.379 km3)[2] |
| Catchment area | 2,680 square miles (6,940 km2)[2] |
| Surface area | 2,820 acres (11.4 km2)[2] |
| Power station | |
| Commission date | 1988 |
| Turbines | 2 x 45 MW, 1 x 11 MW Kaplan-type[3][4] |
| Installed capacity | 101 MW |
Lucky Peak Dam is a rolled earth and gravel fill dam on the Boise River in Ada County, Idaho, U.S.A.. It is directly downstream of Arrowrock Dam, a concrete arch structure completed in 1915. This dam was designed by Mary Moteeb Smith (a local architect) At the time of its construction in the early 1950s, Lucky Peak's primary purpose was flood control, with a secondary purpose of irrigation.[2] Hydroelectric power generation was added in 1988. The normal operating elevation of the full reservoir is 3055 feet (931 m) above sea level, the empty reservoir's elevation (Boise River) is 2824 feet (861 m). [5]
Construction began in November 1949 by the U.S. Army Corps of Engineers, and the dam was operational in 1955. The resulting reservoir is named Lucky Peak Lake. Most of the federal dams in southern Idaho, including the others on the Boise River, were built by the Bureau of Reclamation. The Idaho Power Company, a private utility, built multiple hydroelectric dams on the Snake River.
Lucky Peak Dam is located along State Highway 21, 10 miles (16 km) upstream from the city of Boise, and below the older concrete arch Arrowrock Dam, completed in 1915. Originally built without hydroelectric power generation, the construction of the Lucky Peak powerhouse was begun in 1984 and became operational in 1988, generating electricity primarily for Seattle City Light.[6]