The Nelson River Hydroelectric Project refers to the construction of a series of dams and hydroelectric power plants on the Nelson River in Northern Manitoba, Canada. The project began to take shape in the late 1950s, with the planning and construction of the Kelsey dam and hydroelectric power station, and later was expanded to include the diversion of the upper Churchill River into the Nelson River and the transformation of Lake Winnipeg, the world's 11th largest freshwater lake, into a hydroelectric reservoir. The project is owned and operated by Manitoba Hydro, the electrical utility in the province.
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Several sites on the Nelson River, with potential of millions of horsepower, had been identified as early as 1911 [1], but transmission of power to population centers in the south was beyond the state of the art of electric power transmission at that time. Between 1955 and 1960, studies were carried out to determine what resources would be available for future hydraulic generation in Manitoba. The stations at Kelsey, Kettle, Long Spruce and Limestone were built on the lower Nelson River to support both Manitoba load growth and export plans. Limestone, the largest generating station in Manitoba, is located on the Lower Nelson only 90 km from Hudson Bay. Long-term firm power sales contracts were signed with Northern States Power Company of Minneapolis, Minnesota. Control dams and excavated channels have transformed Lake Winnipeg into a 25,000 km² reservoir for the Nelson hydroelectric system.
The great distance between generating sites on the Nelson River and load centers in southern Manitoba required the use of high-voltage, direct current (HVDC) electric power transmission lines to bring the energy to market. When these lines began operation as the Nelson River Bipole in 1972, they were the longest and highest-voltage direct current lines in the world. The Dorsey converter station is 26 km north-west of Winnipeg, Manitoba.
| Started | Units | Total power (1) (MW) |
Average annual generation (TWh) |
Head | River | |
|---|---|---|---|---|---|---|
| Stations | ||||||
| Kelsey | 1957 | 7 | 211 | 1.8 | 17 m | Lower Nelson |
| Kettle | 1970 | 12 | 1,228 | 7.1 | 30 m | Lower Nelson |
| Long Spruce | 1977 | 10 | 1,010 | 5.8 | 26 m | Lower Nelson |
| Jenpeg | 1979 | 6 | 97 | 0.9 | 10 m | Lake Winnipeg outlet |
| Limestone | 1990 | 10 | 1,340 | 7.7 | 28 m | Lower Nelson |
| Planned Stations | ||||||
| Bonald | - | - | 120 | - | - | Upper Churchill |
| Granville Falls | - | - | 125 | - | - | Upper Churchill |
| Notigi | - | - | 100 | 0.75 | - | Rat |
| Wuskwatim | 2012 | 3 | 200 | 1.55 | 22 m | Burntwood |
| Kepuche | - | - | 210 | - | - | Burntwood |
| Manasan | - | - | 265 | - | - | Burntwood |
| First Rapids | - | - | 210 | - | - | Burntwood |
| Whitemud | - | - | 310 | - | - | Upper Nelson |
| Red Rock | - | - | 190 to 340 | - | - | Upper Nelson |
| Kelsey extension | - | - | 200 | - | - | Lower Nelson |
| Birthday | - | - | 420 | - | - | Lower Nelson |
| Keeyask (Gull) | n/a | - | 600 | 4.4 | - | Lower Nelson |
| Conawapa | n/a | - | 1,380 | 7.0 | - | Lower Nelson |
| Gillam Island | - | - | 1,000 | - | - | Nelson (Mouth) |
(1) Generating station total ratings are approximate.
More than 5000 MW of hydroelectric potential could be developed in Manitoba, which includes 1380 MW at the Conawapa site, 630 MW at the Gull (Keeyask) site, and 1000 MW at the Gillam Island site, all on the lower Nelson river. Other sites have been assessed but are not currently under study for development. All of these developments would require a large increase in electric power exports, since Manitoba load growth will not require this capacity for a generation or more. All of these projects require additional HVDC transmission capacity from the North to the South. One such project, Bipole III, had been discussed with communities on the east side of Lake Winnipeg, but this area has been reserved by the provincial government, making transmission line construction infeasible. The government and Manitoba Hydro have currently rerouted Bipole III through the west side of Manitoba and construction is slated to begin in 2012. However the Progressive Conservative Party of Manitoba has stated that they will build Bipole III through the east side and cancel the west route if elected in the 2011 general election.
Like any other large-scale activity, the Nelson River Hydroelectric Project has not been without controversy.
In 1976, the Churchill River diversion project was set into operation. Flow was diverted by a series of channels and control structures into the Nelson River. Instead of developing hydroelectric sites along the Churchill River, water was diverted by control structures and an artificial channel into the Nelson, thereby increasing flow and saving cost of development. The effects of this diversion on pre-existing water levels and the indigenous Cree and Métis people continue to be felt to this day. Negotiations between the affected Northern communities and Manitoba Hydro continue, to discuss mitigation measures and compensation for loss of traditional resource areas and sites.
The water level of Lake Winnipeg is now regulated by Manitoba Hydro as part of the energy generation operations. Some property owners on the southern edge of the lake feel that the levels are now maintained at a higher average level than would be natural, and attribute erosion of their property to the lake level. Manitoba Hydro has pointed out that the regulation project also allows lake level to be lowered, such as during the 1997 floods, thereby preventing significant property damage.
Although development of the Nelson River system was intended to secure a reliable source of low-cost energy to promote industrial development in Manitoba, such development was not forthcoming. [5] Concerns about the magnitude and cost of Hydro development lead the provincial government to start an inquiry into the management of the company. The Commission of Inquiry into Manitoba Hydro reported in 1979 that Manitoba Hydro had not developed resources in the lowest-cost and most efficient way, and made many recommendations for the governance of Manitoba Hydro. [6]