We provide water level and flow outlooks so communities have information on water conditions on the Churchill, Nelson, and Burntwood rivers during the spring melt.*
Churchill River (Southern Indian Lake to Hudson Bay)
Spring melt expected to start in early May with flows lower than last year but above average.
The upper portion of the Churchill River watershed received above average snowpack while the lower portion near the river mouth has average snowpack. Current inflows from Saskatchewan to Southern Indian Lake are about 30,000 cubic feet per second (cfs) (857 cubic metres per second (cms)) and have not yet started to rise from spring melt. The level of Southern Indian Lake is higher than normal for this time of year at 845.3 ft (257.65 m) and is expected to begin increasing shortly. Outflows through Missi Control Structure have gradually been increasing and are planned to reach 7,500 cfs (212 cms) today and will be increasing gradually over the next few weeks to make room for spring meltwater and reduce the need for higher flows later on. River flows are above average for this time of year.
The Lower Churchill River remains iced-over. Peak flows of about 44,000 cfs (1250 cms) are expected near Churchill between the end of May and mid-June. There is a low risk for significant over-topping of the CR30 road, however water may flow through existing cuts in the road surface, possibly requiring it to be closed to the public. Monitoring will continue with updates provided to the town.
Much of the Churchill River flow is diverted out of Southern Indian Lake through the Churchill River Diversion via the Notigi Control Structure to the Rat and Burntwood rivers. Flows through Notigi are being reduced today from 34,000 cfs (960 cms) to 32,000 cfs (900 cms) to reduce flows on the Burntwood River and into Split Lake during the spring melt.
Nelson River flows expected to rapidly transition from well below average to well above average over the next few weeks.
Recent heavy precipitation across southern Manitoba is flowing into Lake Winnipeg and will eventually flow downstream through the Nelson River. Jenpeg outflows are being increased to accommodate this water. Jenpeg flows are at 65,000 cfs (1,844 cms); Kelsey flows are at 62,000 cfs (1,754 cms).
Split Lake water level, currently at 547.5 ft (166.86 m), is expected to rise about 3 ft through May to elevation 550.5 ft (167.79 m) – this forecasted level is still within the normal high range and is about 5 ft lower than the Spring flood level in 2017. Additional rise is forecasted in June.
*Spring flows depend on how long it takes for snow to melt (i.e. 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.
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 Southern Indian Lake; snow surveys conducted by Manitoba Hydro; and snowpack estimates from satellite data.
If you have any questions or concerns, please contact:
Waterway Community Engagement