Map of Churchill and Nelson rivers with control structures and generating stations.
Enlarge image: Map of Churchill and Nelson rivers with control structures and generating stations.
Churchill River and Nelson River Basins
Spring melt across these basins and will continue for the next couple of weeks.
Precipitation amounts across the Churchill and Nelson River basins have improved over the past year, but total precipitation remains at about one in a ten-year low since April 1.
Lower Churchill River (Southern Indian Lake to Hudson Bay)
The snowpack on the upper Churchill River watershed was above average, while the region near the mouth at Hudson Bay had average snowpack.
Current inflows from Saskatchewan to Southern Indian Lake (SIL) are about 35,000 cubic feet per second (cfs) and falling.
The level of SIL is normal for this time of year at 844.5 ft and will continue to rise over the next seven days to around 844.7 ft. Outflows through Missi Control Structure are around 750 cfs which is typical for this time of year.
Peak flows of about 39,400 cfs occurred near Churchill last week and are steadily declining. Flows near Churchill are currently estimated to be approximately 28,000 cfs.
Burntwood River
Much of the Churchill River flow is diverted out of SIL through the Churchill River Diversion via the Notigi Control Structure to the Rat and Burntwood Rivers. Flows through Notigi have been around 30,000 cfs and are forecasted to drop to about 20,000 cfs mid-June with normal precipitation.
Water levels along the Burntwood River and its lakes have risen and peaked and are now expected to decline due to a combination of decreased Notigi flows and local tributary inflows.
Nelson River Basin
Water conditions on the Nelson River are low to moderate.
Nelson River flow is in a 1 in 4-year low.
Lake Winnipeg is at 712.8 ft (around a one in eight year low). In 2024 it was at 712.6 ft.
Water levels on Cross lake will continue to decline through the spring due to outflow reductions at Jenpeg to help recover storage in Lake Winnipeg following the high winter load period.
Changes in precipitation affect Manitoba Hydro’s operations and water levels across the system. Manitoba Hydro closely monitors water supply conditions across the entire Nelson-Churchill River drainage basin and updates its forecasts and operating plans weekly to ensure adequate energy supply.
Long-term precipitation forecasts are unreliable and there remains considerable uncertainty in water level projections for the late spring and summer period. This is the third and final Spring Outlook.
The Outlook is based on a combination of current and forecasted weather data from Environment and Climate Change Canada; recent and historic streamflow conditions based on both federal and Manitoba Hydro data; Manitoba Hydro regulation models for Reindeer Lake and SIL; snow surveys conducted by Manitoba Hydro; and snowpack estimates from satellite data.
Note that spring flows depend on how long it takes for snow to melt (for example, warm temperatures will cause a fast melt and higher water flows, while cooler temperatures will cause a slow melt and moderate flows for a longer period of time). Conditions can also change rapidly if a large rainfall or snowfall event occurs. Outlook information will be updated as conditions change.
If you have any questions or concerns, please contact:
Andrea Lamboo Miln
Waterway Community Engagement
204-360-3505
WCE@hydro.mb.ca
