Rainbow Dam is a hydroelectric dam on the Missouri River, 29 feet (8.8 m) high and 1,055 feet (322 m) long, located six miles northeast of Great Falls in the U.S. state of Montana.[2]
| Rainbow Dam | |
|---|---|
 Rainbow Dam and Rainbow Falls in 2000 | |
| Official name | Rainbow Dam |
| Location | Cascade County, Montana, US |
| Coordinates | 47°32′04″N 111°12′18″W / 47.53444°N 111.20500°W |
| Opening date | 1910 |
| Operator(s) | NorthWestern Corporation |
| Dam and spillways | |
| Impounds | Missouri River |
| Height | 29 ft (8.8 m) |
| Length | 1,055 ft (321.6 m) |
| Power Station | |
| Installed capacity | 36 MW |
| Annual generation | 268,070,000 KWh (2009)[1] |
History
The dam is named for the downstream Rainbow Falls, a 45 ft (14 m) waterfall that is the third of the five Great Falls of the Missouri. Built in 1910, the dam furnishes water to an eight-unit hydroelectric plant with a capacity of 36 megawatts.[3][4] As the dam's power plant is located over a half-mile downstream, the flow of water over Rainbow Falls and downstream Crooked Falls is significantly reduced during the dry season. The water from the penstocks re-enters the river a few hundred yards east of Crooked Falls. Montana Power Company acquired the dam when it was founded in 1912, PPL Corporation purchased it in 1997 and sold it to NorthWestern Corporation in 2014.
See also
References
External links
- Historic American Engineering Record (HAER) documentation, filed under End of Rainbow Dam Road, Great Falls, Cascade County, MT:
- HAER No. MT-95, "Rainbow Hydroelectric Facility", 8 photos, 11 data pages, 1 photo caption page
- HAER No. MT-95-A, "Rainbow Hydroelectric Facility, Foreman's House", 4 photos, 5 data pages, 1 photo caption page
- HAER No. MT-95-B, "Rainbow Hydroelectric Facility, Ten Stall Garage", 4 photos, 3 data pages, 1 photo caption page
- HAER No. MT-95-C, "Rainbow Hydroelectric Facility, Two Stall Garage", 3 photos, 3 data pages, 1 photo caption page
- HAER No. MT-95-D, "Rainbow Hydroelectric Facility, House No. 16", 4 photos, 5 data pages, 1 photo caption page
- HAER No. MT-95-E, "Rainbow Hydroelectric Facility, Swimming Pool", 3 photos, 3 data pages, 1 photo caption page
- HAER No. MT-95-F, "Rainbow Hydroelectric Facility, Tool House", 4 photos, 4 data pages, 1 photo caption page
- HAER No. MT-95-G, "Rainbow Hydroelectric Facility, Three Stall Garage", 3 photos, 3 data pages, 1 photo caption page
- HAER No. MT-95-H, "Rainbow Hydroelectric Facility, Clubhouse", 7 photos, 12 data pages, 1 photo caption page
- HAER No. MT-95-I, "Rainbow Hydroelectric Facility, Arbor", 1 photo, 3 data pages, 1 photo caption page
- HAER No. MT-95-J, "Rainbow Hydroelectric Facility, Fountain", 1 photo, 3 data pages, 1 photo caption page
- HAER No. MT-95-K, "Rainbow Hydroelectric Facility, Terraced Gardens", 6 photos, 5 data pages, 1 photo caption page
- HAER No. MT-95-L, "Rainbow Hydroelectric Facility, Stone Culvert", 5 photos, 5 data pages, 1 photo caption page
- HAER No. MT-95-M, "Rainbow Hydroelectric Facility, Plank Bridge", 4 photos, 4 data pages, 1 photo caption page
- HAER No. MT-95-N, "Rainbow Hydroelectric Facility, Powder Magazine", 4 photos, 6 data pages, 1 photo caption page