NWT Water Monitoring Bulletin – April 5, 2024

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 

  • Water levels across most of the NWT remain very low.
    • These dry conditions began during the summer and fall of 2022 and have persisted through the end of last year (2023) largely due to hot and dry conditions in northern Alberta and British Columbia, and the southern NWT over the past two summers.
    • The Slave River was below average over the fall and remained that way through winter.
    • Great Slave Lake remains at the lowest water level ever recorded for this time of year.
      • Water levels on Great Slave Lake have been slowly increasing as is normal for this time of year.
    • Great Bear Lake is at its lowest water level ever recorded for this time of year.
    • Flow along the Mackenzie River is at its lowest ever recorded value for this time of year.
  • In the month of March, snowfall amounts received across the territory were generally lower than average. They are presented here as snow water equivalent (SWE). Snow water equivalent (SWE) is the amount of water that remains when snow is melted.
  • Accumulated SWE for the entire winter up to now is well below average in Hay River, Fort Simpson, Fort Smith and Norman Wells, below average in Yellowknife, and well above average in Inuvik.
    • The SWE data presented here are accumulated values from Environment and Climate Change Canada gauges at airports.
    • ECC has completed end-of-season snow surveys, which provide an understanding of how SWE is distributed across the NWT.
      • This information will be available in ECC’s annual Spring Water Level Outlook, which will be published in mid-April.
  • As always, water levels on Great Slave Lake and the Mackenzie River this coming spring/summer will be impacted by snowpack volumes and spring rainfall amounts in northern Alberta and British Columbia.
    • SWE data from these locations show that the snowpack is well below average this winter.
    • Neighbouring jurisdictions are responsible for snow survey measurements in their provinces/territories. ECC works collaboratively with these jurisdictions to compile snow survey results across the Mackenze River basin. These results will also be published in the Spring Water Level Outlook.