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 Monthly Water Monitoring Bulletin – August 7, 2025

Current Status:

• This report is our Monthly Water Monitoring Bulletin, which provides regular updates on water levels and precipitation in the NWT;
• Water levels and flow rates remain relatively low across most of the NWT.
  • Great Slave Lake water level is currently well below average and has been slowly decreasing since end of April 2025, as is normal for this time of year.
  • Slave River water level is below the average range for this time of year.
  • Hay River water level is well below average for this time of year.
  • Liard River water level is average for this time of year.
  • Mackenzie River water level, recorded at several stations along the river, is below average for this time of year.
  • Great Bear Lake remains at its lowest water level recorded for this time of year and flow rates on the Great Bear River are well below average for this time of year.
  • Exceptions to low water levels and flows include:
    • South Nahanni River (well above average)
    • Some smaller rivers in the Great Slave Lake basin, including:
      • Snare River (average)
      • Lockhart River (average)
      • Hoarfrost River (above average)
      • Taltson River (above average)
• Low water levels are the result of extreme drought conditions that began in the summer of 2022 and have persisted through 2023 and 2024. Water levels have since shown some recovery, but this has mostly been limited to small rivers and lakes.
• July precipitation across the NWT was generally below average with most communities, including Fort Smith, Hay River, Fort Simpson, Norman Wells, and Inuvik – receiving below to well below average rainfall. Only Yellowknife recorded approximately average precipitation. July rain events in the southwestern portion of NWT led to rises in flows on some rivers sourced in the Mackenzie Mountains, such as the South Nahanni River.
• July temperatures across the NWT were mostly below average. Fort Smith, Yellowknife, Norman Wells, and Inuvik experienced cooler temperatures than normal, while Hay River and Fort Simpson recorded normal temperatures.
• Water levels on Great Slave Lake and the Mackenzie River for the rest of the summer will be impacted by rainfall amounts in upstream basins, particularly in northern Alberta and British Columbia.
  • So far this spring and summer, precipitation in most of these areas has been below to well-below average.
  • Some parts of the Liard River basin had average and above average precipitation.
• Climate forecasts from ECCC for August to October indicate warmer than normal temperatures for most of the NWT, with the exception of the northwest along the Beaufort coast where it is expected to be colder than normal. Forecasts also show a 40-50% chance of above average precipitation for central and southern portions of the NWT, and average to above average precipitation in the west.