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

• Water monitoring technical bulletin – May 4, 2023

Current status – NWT 

• On the Liard River and on the Mackenzie River at Fort Simpson, water levels are fluctuating under the ice and responding to upstream ice movement;
• Ice has yet to break on the Mackenzie River at Fort Simpson, or on the Liard River at the mouth (i.e. the confluence with the Mackenzie River);
  • There is an ice jam on the Mackenzie River just upstream of the confluence with the Liard River;
    • This jam has caused water levels to rise behind it (water levels are rising at the Mackenzie River at Strong Point gauge, near the mouth of the Rabbitskin River);
    • There is a large stretch of open water originating downstream of Jean Marie River and extending to the head of the ice jam;
    • Ice had yet to break in Jean Marie River as of early this morning.
  • Water levels in Fort Simpson at breakup will depend on the timing of when Mackenzie and Liard ice starts moving and how it clears downstream;
• Warmer than seasonal temperatures are forecast for the southern Dehcho region (lower Liard and upper Mackenzie basins) over the next week;
  • Daily highs will be in the low- to mid- 20s °C over the next couple of days and are forecast to exceed previously recorded highs on Saturday and approach 30°C. The sun and warm weather will continue to soften river ice.

Current Status – Liard River

• Ice on the Liard River has moved past Fort Liard;
• Ice has not yet broken on the Liard River at Fort Simpson (as of 12:00);
• Most of the lower Liard River basin is snow-free;
• Water levels spiked at Fort Liard yesterday morning but have since receded as the ice moved downstream
  • Ice jams and runs are likely along the Liard River as ice continues to move;
  • Water levels remain within a normal range;
• The southern Dehcho region will continue to receive unseasonably warm weather through the weekend.

Current Status –Mackenzie River

• An ice jam has developed on the Mackenzie River just upstream of the confluence of the Liard River near Fort Simpson;
  • The Mackenzie River at Strong Point gauge (near the mouth of the Rabbitskin River) has been steadily increasing over the last two days in response to the jam;
  • Ice has yet to break at Fort Simpson (as of 13:00);
  • There is a large stretch of open water between Jean Marie River and Fort Simpson;
  • High temperatures continue to soften the river ice.
• Water levels are rising underneath the ice at the Mackenzie River at Fort Simpson and remain within the normal range;
  • The water level in Fort Simpson will be dependent on the relative timing of when ice moves on the Mackenzie and Liard rivers and how it clears downstream of Fort Simpson.
• Warm temperatures in the region will soften river ice and expedite breakup.