NWT Water Monitoring Bulletin – April 27, 2023

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

  • Snowmelt, river ice melt, and rises in water levels continue in southern basins in the NWT;
  • On the Hay River, ice continues to break up and shift;
  • On the Liard River and on the Mackenzie River at Fort Simpson, water levels are beginning to rise under the ice, but the rates of increase are still small
  • Warmer than seasonal temperatures are forecast for the Hay River and lower Liard River basins this weekend, beginning Friday and will persist into next week.
    • Snowpack in the upper (i.e., southern) Hay River basin has largely melted.
    • Temperatures will approach 20°C in the southern parts of the basins and will rapidly melt residual snowpack and soften river ice.

Current Status - Hay River

  • Snowpack in the upper (i.e., southern) part of the Hay River basin has largely melted;
  • Water levels continue to slowly rise on the Hay River and its tributaries
    • Rates of rise are normal for this stage of breakup;
  •  Ice continues to degrade on the Hay River, with small amounts of local ice movement and consolidation;
    • Small patches of open water are developing;
  • Warmer than normal temperatures are forecast in the Hay River basin beginning on Friday and persisting into next week.
    • Highs of near 20°C are forecast for the upper (southern) part of the basin;
    • Warm temperatures should continue to soften the ice cover;
  • Refer to the Town of Hay River website for the most up-to-date information, as well as webcam images of current conditions.

Current Status – Liard River

  • Snowpack continues to melt across the basin;
  • Ice remains largely intact along the Liard River within the NWT;
    • Breakup has initiated on the Petitot River, a tributary of the Liard River, and should continue over the coming days;
    • Breakup is well underway on the Fort Nelson River (northeastern BC), a tributary of the Liard River;
  • Water levels are slowly increasing underneath the ice on the Liard River at Fort Liard
    • The low rate of water level rise is normal for this time of year
  • The southern Dehcho region is forecast to receive warmer than normal temperatures beginning on Friday that will persist into next week.
    • Fort Liard and Nahanni Butte are forecast to receive small amounts of rain (10-20 mm) on Sunday night and Monday morning

Current Status – Slave River/Great Slave Lake/Mackenzie River

  • Break up is well underway in the Peace/Athabasca basins, which drain into the Slave River;
    • Break up has been mostly thermal on the Peace and Athabasca rivers;
  • Satellite imagery shows small open water sections on the Mackenzie River upstream of Jean Marie River, but river ice remains largely intact;
  • Water levels are slowly beginning to rise underneath the ice at the Mackenzie River at Fort Simpson, but the rate of increase is still very small;
  • The southern Dehcho region is forecast to receive warmer than normal temperatures beginning on Friday that will persist well into next week.