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

• NWT Water Monitoring Bulletin – October 7, 2024

Current Status:

• Water levels and flow rates remain very low across most of the NWT. There have been no significant changes across gauged rivers and lakes, and at most locations water levels and flow rates have started to decrease as fall freeze up approaches. Great Slave Lake remains at its lowest water level recorded for this time of year and is lower than last year at this time.
  • Flow rates on the Slave River have decreased through September and are at their lowest recorded value for this time of year.
  • Flow rates on the Hay River are well below average for this time of year.
  • Flow rates on the Liard River are below normal for this time of year.
  • Flow rates at most locations along the Mackenzie River are well below average or at their lowest recorded values for this time of year.
  • Flow rates at the outlet of Great Bear Lake are well below average for this time of year.
  • Water levels in the Mackenzie River Delta have been variable in September and are near average or below average for this time of year.
  • Exceptions to low water levels and flow rates include:
    • Small, local basins in the Beaufort Delta region
    • Arctic Red River
    • Lockhart River
    • Coppermine River
    • South Nahanni River
       
• Low water levels continue to be the result of extreme drought conditions that began in the summer of 2022, and have persisted through 2023 and 2024.
   
• Cumulative precipitation for the spring and summer of 2024 was well below average for NWT communities, apart from Inuvik with well above average precipitation.
   
• September precipitation across the NWT was variable between communities. Fort Smith and Yellowknife received approximately average precipitation. Norman Wells received below average precipitation, and Hay River and Fort Simpson received well below average precipitation. Inuvik precipitation was well below average.
   
• September temperatures across the NWT were much warmer than average.
   
• Low water levels on Great Slave Lake and the Mackenzie River are influenced by rainfall received in northern British Columbia, Alberta, Saskatchewan, and southern NWT.
  • Precipitation in the Mackenzie River basin in northern BC and AB has been approximately average so far this summer, with some variability between communities.
  • Average precipitation has not been enough to overcome the extreme drought and soil moisture deficit. Several months of above average precipitation is needed to raise water levels.
  • As of August 25, 2024, BC Hydro started filling the Site C reservoir. The process is anticipated to finish by mid-November. The filling of Site C is projected to have a relatively minor impact on our water levels compared to the effects of our current drought wich caused water levels to drop significantly during the summer of 2023.
• Guidance from Environment and Climate Change forecasts suggests NWT is most likely to see near to above normal precipitation (greater than 40% chance) for the months of October, November and December. The above normal precipitation may be observed primarily in northern regions of the territory.