NWT Water Monitoring Bulletin – May 06, 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.

No update will be provided tomorrow unless conditions require. 

Technical data

Current status – NWT 

  • The water level on the Mackenzie River at Fort Simpson (Village sensor) peaked near 11.0 m at about 20:30 last night and have receded since then; o The current water level is 8.1 m (as of 10:00);
  • The water level at Fort Simpson rose by approximately 4.5 m yesterday as a long ice run moved down the Mackenzie River past Fort Simpson; the water level began to drop once the ice run passed;
  • The risk of flooding in Fort Simpson in 2023 is now very low;
  • Counter to the very warm spring in the southern NWT, the Sahtu and Beaufort Delta regions have experienced a colder-than-normal spring;
  • Although break up is not yet imminent, early indicators show that there is an increased potential for flooding in the Peel and Arctic Red river basins; o This increased potential stems from highest on record over-winter water levels, high precipitation last summer/fall, high snowpack, and a colder-than-normal spring;
    • The maximum extent of spring break up water levels will be dependent on weather conditions over the coming weeks;
    • More information for land users in the basins is available here.

Current Status – Liard River

  • Remaining ice on the Liard River is moving well;
  • Water levels on the Liard River near the mouth increased rapidly yesterday as Mackenzie River ice moved through Fort Simpson, and impeded Liard River flow;
  • According to gauge photos, the water levels have since receded (the water level gauge sensor was damaged yesterday evening).

Current Status – Peel River and Beaufort Delta

  • Break up has yet to commence in the Peel River and Beaufort Delta;
  • Early indicators show the potential for high water and out-of-bank flows on the Peel River and Arctic Red rivers at break up;
  • More information will be available as the snowpack melts.

Current Status –Mackenzie River

  • Water levels on the Mackenzie River at Fort Simpson peaked close to 11.0 m last night (at the Village sensor) around 20:30 but have declined as the ice run has moved past Fort Simpson;
    • In most years, the Liard River will break before the Mackenzie River, but this year the Mackenzie River broke first;
      • This is likely because of low water on the Liard River, and low volumes of snowmelt runoff from tributaries that were not able to raise the ice off of the river banks;
    • The current water level on the Mackenzie River at Fort Simpson (Village gauge) is 8.1 m (as of 10:00);
  • Risk of flooding in Fort Simpson is now very low.