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 has started in parts of these basins and will continue for the next few weeks. Precipitation amounts across the Churchill and Nelson River basins have improved over the past year, but total precipitation remains at around a 1 in 10-year low.
Lower Churchill River (Southern Indian Lake to Hudson Bay)
The snowpack on the upper Churchill River watershed is above average, while the region near the mouth at Hudson Bay has average snowpack.
Current inflows from Saskatchewan to Southern Indian Lake (SIL) are about 25,000 cubic feet per second (cfs) and rising.
The level of SIL is normal for this time of year at 843.9 ft and will begin rising over the next 7 days. Outflows through Missi Control Structure are around 1,600 cfs which is typical for this time of year. The Lower Churchill River is in the early stages of melting. Peak flows of about 39,400 cfs are expected near Churchill between mid-May and early June.
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 27,500 cfs and are forecasted to rise to about 32,000 cfs through spring.
Water levels along the Burntwood River and its lakes are rising due to a combination of increased Notigi flows and local tributary inflows.
Nelson River Basin
Water conditions on the Nelson River are low to moderate.
The Nelson River flow is at a 1 in 4-year low. Lake Winnipeg is at 712.5 ft (around a 1 in 8-year low). In 2024 it was at 712.2 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. Sipiwesk Lake is rising as Kelsey forebay is refilled.
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. Manitoba Hydro will continue to provide spring outlooks for the Lower Churchill, Burntwood and Nelson Rivers in the coming weeks.
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
