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.* This spring outlook is the first for the season.
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 (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 32,000 cubic feet per second (cfs) (905 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 845.9 ft (257.84 m) and is declining slowly. Outflows through Missi Control Structure are planned to be increased from 4,000 cfs (115 cms) to 7,500 cfs (212 cms) on April 22 to make room for spring meltwater and to 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 55,000 cfs (1520 cms) are expected at the mouth of the river 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 to the town.
Burntwood River
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 will be reduced to about 32,000 cfs (900 cms) shortly for several weeks to reduce flows on the Burntwood River during spring melt.
Nelson River
Flows on the Nelson River are low for this time of year as are water levels on Split Lake (currently at 547.6 ft (166.9 m) above sea level which is about a foot lower than this time last year).
Widespread dry conditions throughout the Lake Winnipeg basin last fall have gotten wetter with all the snow and melting snow received in the basin since that time, resulting in increasing but still below average flows to the Nelson River. Spring flows are expected to remain below average.
*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:
Dale Hutchison
Waterway Community Engagement
204-360-3505
WCE@hydro.mb.ca