| Thomson Dam | |
|---|---|
&sq=&lang=&file=File:Thomson_Dam,_Minnesota.jpg) Downstream face of the main Thomson Dam on the St. Louis River in 2017 | |
&sq=&lang=&file=File:USA_Minnesota_relief_location_map.svg)  Location of Thomson Dam in Minnesota | |
| Location | Carlton County, Minnesota, U.S. |
| Coordinates | 46°39′59.10″N 92°24′25.80″W / 46.6664167°N 92.4071667°W |
| Purpose | Power |
| Status | Operational |
| Construction began | 1905 |
| Opening date | 1907 1914-48 expanded[1] 2012 damaged 2014 reconstructed |
| Built by | Great Northern Railway |
| Owner(s) | Minnesota Power |
| Dam and spillways | |
| Type of dam | Earth Embankment, Concrete Gravity, Arch |
| Impounds | Saint Louis River |
| Height | Main: 15 ft (4.6 m)[2] Canal: 45 ft (14 m) |
| Length | Main: 1,600 ft (490 m)[2] Canal: 3,500 ft (1,100 m) |
| Spillways | 2 |
| Spillway type | gated |
| Spillway capacity | 60,000 cu ft/s (1,700 m3/s)[3] |
| Reservoir | |
| Creates | Thomson Reservoir |
| Total capacity | 4,352 acre⋅ft (5,368,000 m3)[2] |
| Catchment area | 9,154 sq mi (23,710 km2)[2] |
| Surface area | 649 acres (263 ha)[4] |
| Thomson Hydro | |
| Coordinates | 46°39′17.91″N 92°20′1.032″W / 46.6549750°N 92.33362000°W |
| Hydraulic head | 375 ft (114 m) |
| Turbines | 6 [1] |
| Installed capacity | 72 MW[1] |
| Annual generation | 280 GWh[5] |
| Website http://mphydro.com/ | |
Thomson Dam, also known as the Thomson Hydro Station[1] or Thomson Water Project,[6] is an embankment and concrete gravity dam on the Saint Louis River near the town of Thomson in northeastern Minnesota, United States. It consists of a 1600-foot (488 m) long primary structure and multiple supplementary dams which, together with precambrian rock outcrops known as the Thomson formation, impound the river to create Thomson Reservoir.
The tallest dam in the complex is 51.6 feet (16 m) and the longest is 3500 feet (1067 m). A series of gate houses, a canal, forebay, and underground penstocks supply a hydropower plant located 3 miles away in Jay Cooke State Park. With an installed capacity of 72 MW and an annual generation of approximately 280 GWh, the Thomson project is the largest hydroelectric facility in the state.[7]
- ^ a b c d "Thomson Hydro Station". Minnesota Power: Our System. Retrieved July 30, 2017.
- ^ a b c d Cite error: The named reference
NIDwas invoked but never defined (see the help page). - ^ Cite error: The named reference
Pinewas invoked but never defined (see the help page). - ^ "Thomson Reservoir". Minnesota Power: Reservoirs and Recreation. Retrieved July 30, 2017.
- ^ "2015 Integrated Resource Plan" (PDF). Minnesota Power. September 1, 2015.
- ^ "Thomson Dam, Thomson, MN". John A. Weeks III. Retrieved July 30, 2017.
- ^ "Listing of Minnesota Hydropower Facility Sites" (PDF). Minnesota Department of Natural Resources. 2017. Retrieved July 30, 2017.