NWT Water Monitoring Bulletin – July 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 –Territorial Overview

  • Water levels and flow rates on many lakes and rivers across the NWT, especially in southern regions, remain very low, and in some cases, are the lowest ever recorded for this time of year.
    • Great Slave Lake remains at its lowest water level recorded for this time of year and is well below the previous lowest recorded value.
    • Flow rates on the Slave River (the major tributary to Great Slave Lake) are below average for this time of year.
    • Most other gauged tributaries to Great Slave Lake are either below average or at their lowest recorded value for this time of year.
    • Flow rates at most locations along the Mackenzie River are below average or at their lowest recorded values for this time of year.
    • Water level on Great Bear Lake is at its lowest recorded value for this time of year.
    • Flow rates on the Arctic Red River and the Peel River (both tributaries to the Mackenzie River) are at their lowest recorded values for this time of year.
    • Exceptions to low flow rates are those recorded on the South Nahanni River and Liard River, which are approximately average.
      • Water levels on small, local lakes and rivers in the Gwich’in and Inuvialuit regions are above normal due to high winter snowpack volumes and above-average May precipitation.
  • The low water levels are the result of multi-year drought conditions that began in the summer of 2022.
  • Water levels on Great Slave Lake and the Mackenzie River this summer and fall will be influenced primarily by rainfall amounts received in the major sub-basins located in northern Alberta, British Columbia and Saskatchewan, and the southern NWT.
    • Cumulative precipitation so far this spring and summer from gauges in these regions has been within the normal range, but this has not been enough to recover from the very dry conditions.
    • For water levels to rebound to more normal levels, a significant amount of precipitation (multiple months above average) is needed.
  • June precipitation across the NWT was generally below average, except for Fort Smith which received above average precipitation.
  • June temperatures across the NWT were variable, with a general trend of cooler than normal temperatures in the south (Fort Smith and Hay River), average temperatures in the central part of the territory (Yellowknife and Fort Simpson), and warmer than average temperatures in the north (Norman Wells and Inuvik).
  • Guidance from Environment and Climate Change Canada (ECCC) suggests that cumulative precipitation over the southern Mackenzie River basin will be lower than normal for the next three months (July, August, September), with July having the lowest amount compared to that month’s average.