NWT Water Monitoring Bulletin – May 11, 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;
  • Water levels on the Hay River and its tributaries continue to steadily rise in response to rain and snowmelt from the recent storm event;
    • It is expected that water levels at gauge locations will either continue increasing steadily or hold at their current level;
    • If remaining river ice that is currently sitting upstream moves into the community, there is potential for rapid water level increases;
  • Fort Liard reported some localized flooding yesterday late afternoon/evening as a result of an ice jam on the Liard River near the community;
    • Ice remains present in Fort Liard but water levels have decreased;
  • Ice on the Mackenzie River had not yet started moving at Jean Marie River as of this morning;
  • The Mackenzie River at Fort Simpson has primarily open water and Liard River ice continues to clear well at this time (12:00);
  • Water levels downstream on the Mackenzie River are slowly starting to rise, as is normal for spring break up.

Hay River

Current status

  • Water levels on the Hay River and its tributaries continue to steadily rise in response to rain and snowmelt from the recent storm event;
  • It is expected that water levels at gauge locations will either continue increasing steadily or hold at their current level;
  • The impact of the existing/rising water levels on the downstream locations will depend on how and when remaining ice clears out of the river;
  • If remaining river ice that is currently sitting upstream moves into the community, there is potential for rapid water level increases;
  • Climate models from Environment and Climate Change Canada reported up to 125 mm of precipitation in the Hay Basin over the duration of the storm event;
  • The water level response on the Hay River and its tributaries to precipitation is rapid at this time of year due to low basin storage and frozen ground;
  • 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 11 at 10:00. Photo courtesy of Water Survey of Canada and GNWT.

Liard river

Current status

  • Fort Liard reported some localized flooding yesterday late afternoon/evening as a result of an ice jam on the Liard River near the community;
    • Ice remains in place on the Liard River at Fort Liard, but water levels have decreased since yesterday;
    • Fort Liard Flood Watch continues to monitor the river for additional ice;
  • There is open water on the Liard River at the Fort Simpson ferry crossing.

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

 

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

Current status

  • Ice continues to break up on the Slave River;
  • The Mackenzie River at Fort Simpson has primarily open water and Liard River ice continues to clear well at this time (12:00);
    • Water levels at the Village sensor are under 9.0 m as of 12:00;
    • Ice has impacted the Mackenzie River at Fort Simpson hydrometric gauge so real time data are not available from that gauge;
  • Ice on the Mackenzie River had not yet started moving at Jean Marie River as of this morning;
  • Under ice water levels downstream on the Mackenzie River are slowly starting to rise, as is normal for spring break up.

Above – Dehcho (Mackenzie River) at Strong Point hydrometric gauge photo from May 11 at 10:00. Photo courtesy of Water Survey of Canada and GNWT.