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 845.5 ft (257.71 m) and is expected to begin increasing shortly. Outflows through Missi Control Structure were increased from 4,000 cfs to 5,000 cfs (142 cms) last week 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 have been at 34,000 cfs (960 cms) all winter and may be reduced to about 32,000 cfs (900 cms) shortly for several weeks to reduce flows on the Burntwood River during spring melt.
Flows on the Nelson River are low for this time of year as are water levels on Split Lake (currently at 547.7 ft (166.93 m) above sea level which is lower than this time last year and about 2.5 ft higher than the level during last summer’s drought).
Widespread dry conditions throughout the Lake Winnipeg basin last fall have gotten wetter with all the snow and recent precipitation received in the basin since that time. Spring flows are expected to transition from below average to slightly above average through May.
*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