Hydroelectric Development
Kelsey Generating Station
Kettle Generating Station
Long Spruce Generating Station
Limestone Generating Station
By the 1950s, it was recognized that Lake Sturgeon in the Nelson River had been severely impacted by exploitation. In addition, habitat changes from hydroelectric development began to affect the populations. Information on each of the generating stations on the Lower Nelson River is below, with more information available on the Manitoba Hydro website.
Kelsey Generating Station
- 224 MW Power, 17.1 m head
- Constructed between 1957 and 1961
- Built at Kelsey Rapids to supply power to the International Nickel company’s mining and smelting operations in Thompson
- Flooded approximately 164 km2, extending upstream to Sipiwesk Lake
- Habitat downstream of the station was altered as a result of re-directed river flow. However, the station does little or no cycling, leaving the downstream environment free of rapid fluctuations in flow or dewatering/rewatering of the riverbed
Kettle Generating Station
- 1,220 MW Power, 30 m head
- Constructed between 1966 and 1974
- Second generating station on the Nelson River and the first on the lower Nelson River
- Affected the fish community in the reach of the river extending to Gull Rapids, and possibly affected upstream movements of fish over Gull Rapids (effects are not expected to have extended further upstream)
- Increased water levels on the Nelson River immediately upstream by approximately 31.5 m and flooding 221 km2 in the reach of the Nelson River and tributaries between Gull and Kettle rapids
- In the mid-1960s, inflow of the Butnau River to the Nelson River was blocked by a dam and the river was redirected into the Kettle River such that it would discharge downstream of the GS
- Open water levels were increased in 1998 after completion of dam safety upgrades
- Operation of the GS causes daily and weekly water level changes on the reservoir (Stephens Lake)
Long Spruce Generating Station
- 980 MW Power, 26 m head
- Constructed between 1973 and 1979
- Flooded 14.5 km2
Limestone Generating Station
- 1350 MW Power, 27.6 m head
- Constructed between 1976 and 1992
- Flooded 2.2 km2
Lake Winnipeg Regulation/Churchill River Diversion
In the early 1970s, Manitoba Hydro initiated the Lake Winnipeg Regulation (LWR) and the Churchill River Diversion (CRD) projects to further increase the hydroelectric potential of the Nelson River. Lake Winnipeg Regulation enables Manitoba Hydro to store water during the open-water season for use during winter when hydroelectric demand was highest. Regulation of Lake Winnipeg was achieved by constructing: 1) channels to improve outflows from Lake Winnipeg; and 2) a generating station (126 MW Jenpeg GS and Control Structure) in the upper reach of the river to regulate flows. The purpose of the CRD was to increase flows in the Nelson River where hydroelectric development would be concentrated. It included a control structure at Missi Falls at the outlet of Southern Indian Lake, which would allow diversion of approximately 900 m3/sec of water into the Burntwood River and subsequently into the Nelson River at Split Lake. Both projects were completed by 1976.
Since 1976 the LWR and CRD water management projects have combined to influence water levels and flows in the lower Nelson River and have significantly increased hydroelectric generation. The CRD has increased flows 8-fold in the Burntwood River from a long-term average of approximately 110 cms to 850 cms. This has increased the total inflow to Split Lake by 32% and also changed flow patterns. The CRD and LWR have combined to change the seasonal flow pattern so that the highest flows typically occur during the winter rather than during the summer. Operation of the CRD underwent testing and annual adjustments and as a result, discharge was not consistent until an Augmented Flow Program was fully established in 1986. The average post-CRD/LWR water level in Split Lake is 167.2 m, which is 0.4 m higher than pre- CRD/LWR levels. The change in seasonal flow distribution and the 32% increase in flow also was experienced in waterbodies downstream of Split Lake.
Overall Impacts
Construction of the Kettle GS, and subsequently the Long Spruce and Limestone GSs, resulted in daily and weekly cycling of flows in both the impounded areas and in the river downstream. Depending on local conditions, large areas of the riverbed are dewatered and wetted on a daily or weekly basis. Prior to construction of the GSs, ice cover would develop up the river starting at the Nelson River estuary. After impoundment, stable ice cover formed on the reservoirs.
In summary, hydroelectric development has altered the Nelson River by: changing the amount and timing of flows on the Nelson River; causing daily and weekly dewatering of river channels and lake shores, directly eliminating falls and rapids through the placement of generating stations; increasing water depths; flooding terrestrial habitat; causing erosion and increasing sedimentation; altering water quality; decreasing velocities in reservoirs; inundating rapids, diverting the Butnau River; and blocking fish movement along the river. While these impacts have certainly had some effect on Lake Sturgeon populations in the river, the full extent of the effects remain unknown.
(With information from Manitoba Hydro. 2014. Regional cumulative effects assessment. Part IV Physical Environment. Manitoba Hydro, Winnipeg, MB. 53 p.)
