NWT Water Monitoring Bulletin – May 10, 2022

News Type: 
Water monitoring bulletin

The Government of the Northwest Territories maintains water monitoring stations across the territory to keep track of water levels and flow rates in areas of potential flood risk for communities.

This information is provided regularly to territorial and regional emergency managers to help understand the status of waterways across the NWT in the lead-up to, and during spring break-up – the highest-risk period for floods in the Northwest Territories.

Technical data

Current status - NWT

  • Evacuation Orders and Alerts for the Town of Hay River and K'atl'odeeche First Nation remain in place for certain areas;
  • Provisional water levels recorded at the Hay River near Hay River gauge are higher than the peak from last year;
    • Provisional data indicate that all tributaries to the Hay River are recording water levels higher than the ice-induced peak from last week and could be the highest in their respective periods of record (which in some cases is only 10 years);
  • The potential for further/continued high water levels remains high while ice remains present on the river and recent snowfall continues to melt in the Hay River basin;
  • Ice from the Liard River is moving down the Dehcho (Mackenzie River) past Fort Simpson. Water levels are currently at 11.0 m and were reported to have reached a peak of 11.7 m last night at a Village of Fort Simpson level sensor.


Hay River

Current status

  • Based on images from the border with Alberta, there has been no additional ice moving down river for over two days;
  • The storm system that resulted in high precipitation over the basin has dissipated;
    • There no is significant precipitation in the forecast;
    • Sun and warmer temperatures should return tomorrow;
  • All functioning gauges on the Hay River and its tributaries are currently showing the highest provisional water level on record;
    • Note: These are real-time, provisional values that have not been verified by the Water Survey of Canada;
    • Note: Some gauges have relatively short records (e.g., 2012 to present);
  • Water levels at the Hay River near the AB-NT border site continue to slowly rise as recent rain and snow continues to move through the basin;
  • The effect of how these rising water levels will affect the Town of Hay River will depend on how and when the ice clears out of the river;
  • The water level response on the Hay River and its tributaries to precipitation is very rapid at this time of year due to low basin storage and frozen ground;
  • Climate models from the Alberta River Forecast Centre reported up to 120 mm of precipitation in the Hay Basin over the weekend;
  • Refer to the Town of Hay River website for the most up-to-date information, as well as webcam images of current conditions.

Above – Hay River near the Town of Hay River hydrometric gauge photo on May 10 at 12:00. Photo courtesy of Water Survey of Canada and GNWT.

Liard river

Current status

  • Ice has broken up along the Liard River;
    • It is running in some locations and jammed in others;
    • Ice remains jammed at Fort Liard as of 12:00 today;
  • Ice is running at the Liard River ferry crossing near Fort Simpson and is pushing down the Dehcho (Mackenzie River).

Above – Liard River near the mouth hydrometric gauge photo from May 10 at 11:00. Photo courtesy of Water Survey of Canada and GNWT.


Slave River/Great Slave Lake/Dehcho (Mackenzie River)

Current status

  • Ice is breaking up on the Slave River;
    • Parks Canada is hoping to fly the river this afternoon to get a better idea of river ice (cloudy conditions over the past four days have prevented optical imagery);
  • Ice from the Liard River has been moving on the Dehcho (Mackenzie River) at Fort Simpson, beginning yesterday evening;
    • Water levels (manual readings at the Village of Fort Simpson Pumphouse) reached a peak of 11.7 m last night and are currently reading 11.0 m;
    • Ice has impacted the Mackenzie River at Fort Simpson hydrometric gauge so real time data are not available;
  • Temperatures are forecast to return to normal for the next five days.

Above – Dehcho (Mackenzie River) at Strong Point hydrometric gauge photo from May 10 at 12:00. Photo courtesy of Water Survey of Canada and GNWT.