NWT Spring Break-Up Water Update and Monthly Water Monitoring Bulletin

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 – Spring Break-Up

  • Break-up is progressing along the Mackenzie River.
    • The ice front has moved downstream of Norman Wells;
    • There are intermittent stretches of open water and sheet ice on the Mackenzie River between Norman Wells and Tsiigehtchic.
  • Water levels on the Mackenzie River upstream of the ice front remain very low.
  • On the Peel River, water levels are rising, and ice is beginning to move upstream of Fort McPherson.
    • Snow and ice melt have substantially increased as a result of temperatures well above zero degrees over the previous two days.
    • Out of bank flows and potential flooding are possible this weekend around Fort McPherson if a strong ice jam forms downstream of the community.
    • Imagery indicates that ice jams are beginning to form above the community;
    • ECC will continue to monitor ice conditions through radar and optical satellite imagery.
  • Temperatures for the next three days are forecast to be well above zero in the Sahtu (warmer than average).
  • In the Peel River basin and Beaufort Delta, daytime highs are forecast to be just above zero with lows near zero.

Current Status – Monthly Water Monitoring Bulletin

  • Water levels and flow rates on lakes and rivers across most of the NWT remain very low, and in some cases are the lowest ever recorded for this time of year.
    • The low water levels are the result of extremely hot and dry conditions that began during the summer of 2022 and persisted throughout 2023.
    • Much of the Great Slave Lake basin (which includes areas in northern British Columbia, Alberta, and Saskatchewan) received very little snowfall this year.
    • Flows rates on the Slave River were below average over the winter and are currently at the lowest recorded value for this time of year.
    • Great Slave Lake remains at its lowest water level recorded for this time of year and is much lower than the previously recorded lowest value at this time of year.
    • Flow rates at most locations along the Mackenzie River are either below average or at their lowest recorded value for this time of year.
    • Flow rates along the Liard River are below average for this time of year.
    • The water level on Great Bear Lake is near the lowest on record for this time of year.
  • One notable exception to the low water levels across the territory is the Peel River.
    • Water levels were higher than average over winter, and snowmelt and break-up have yet to initiate a rise in spring water levels.
  • In April, temperatures across the territory were generally well above average. Precipitation was generally well below or below average. Exceptions include:
    • Average precipitation in Fort Simpson and above average precipitation in Fort Smith.
    • April precipitation makes up a small percentage of total spring/summer precipitation. The highest precipitation amounts usually occur in the months of July and August.
  • Information provided by Environment and Climate Change meteorologists suggests that precipitation over the Mackenzie River basin in May, June, and July will be lower than normal, with the largest anomalies (i.e., the least precipitation relative to normal) occurring in June.
    • One exception is more precipitation than normal predicted for the Liard River basin in May.
  • Water levels on Great Slave Lake and the Mackenzie River this coming summer will be impacted by rainfall amounts in northern Alberta and British Columbia.
    • Precipitation data from these locations during April was approximately average.