LaGrande Dam
Hydroelectric dam in Washington, U.S.
From Wikipedia, the free encyclopedia
LaGrande Dam (or La Grande Dam) is a hydroelectric dam on the Nisqually River, on the border of Pierce County and Thurston County, Washington. LaGrande is the lesser of two coordinated dams on the Nisqually, situated two miles north (downstream) of the other, Alder Dam. Both are owned by Tacoma Power.[1]
.jpg)
| LaGrande Dam | |
|---|---|
| |
 Interactive map of LaGrande Dam | |
| Location | Pierce County \ Thurston County |
| Coordinates | 46°49′22″N 122°18′15″W |
| Status | Operational |
| Opening date | 1945[1] |
| Construction cost | $9.7 Million[1] |
| Owner | Tacoma Power[1] |
| Dam and spillways | |
| Impounds | Nisqually River |
| Height (foundation) | 217[1] |
| Height (thalweg) | 192[1] |
| Length | 710[1] |
| Width (crest) | 12[1] |
| Width (base) | 85[1] |
| Reservoir | |
| Creates | LaGrande Reservoir |
| LaGrande Powerhouse[1] | |
| Commission date | 1912 |
| Turbines | 4x 6 MW, 1x 40 MW[2] |
| Installed capacity | 64 MW[2] |
| Annual generation | 297.313 GWh[3] |
| Website https://www.mytpu.org/about-tpu/services/power/about-tacoma-power/dams-power-sources/nisqually-river-project/lagrande-dam/ | |
Hydroelectric power was first produced from LaGrande in November 1912 as the first independent project of Tacoma Power.[4] The present structure was completed in 1945, the same year as Alder Dam's construction. At 192 feet high, the dam impounds about 2,700 acre-feet (3,300,000 m3) of water.
Neither LaGrande Dam nor its narrow two-mile-long impoundment, LaGrande Reservoir, is accessible to the public.
Hydroelectric power capacity
| Generator | Nameplate Capacity (MW)[2] |
|---|---|
| 1 | 6.0 |
| 2 | 6.0 |
| 3 | 6.0 |
| 4 | 6.0 |
| 5 | 40.0 |
| Total | 64.0 |
