In this section
The Department of Environment and Natural Resources has a long-established partnership with the Water Survey of Canada to collect stream flow, water level and lake level measurements routinely across the territory, including at locations where there are communities at risk of flooding. These data are available to the public at https://wateroffice.ec.gc.ca.
A summary of these and other data and information are provided regularly to territorial and regional emergency managers to help understand the status of waterways near communities at risk of flooding in the lead-up to, and during spring break-up – the highest-risk period for flooding in the Northwest Territories.
Important note on flood risk
Water levels and flow do not necessarily predict flooding – especially at spring break-up, when most floods in the Northwest Territories take place.
Most flooding in the NWT occurs because of ice-jams forming in a river during break-up of the river ice. These floods can happen regardless of the water levels.
However, the consequences of an ice jam can be more severe in at-risk communities when the over-winter water level is already high.
Any community near a body of water is at risk of a flood. However, several communities are considered to be at higher-risk of flooding. A list is maintained by the public safety division of the Department of Municipal and Community Affairs. Note that this list is current as of publishing. The most up-to-date list can be found here.
- Hay River (Hay River)
- Kátł’odeeche (Hay River)
- Nahanni Butte (South Nahanni River, Liard River)
- Fort Liard (Liard River)
- Fort Simpson (Liard River, Mackenzie River)
- Aklavik (Mackenzie River)
- Fort Good Hope (Mackenzie River)
- Tulita (Mackenzie River)
- Jean Marie River (Mackenzie River)
Factors influencing flood risk
The potential occurrence and severity of flooding during the spring break-up depend in large part on the weather through springtime and how it interacts with existing water levels and snow pack amounts.
Warmer than normal temperatures, extreme rain, or rain on snow events can increase the likelihood of flooding.
Flooding in the NWT can also occur in open water conditions because of high rainfall.
Flood risk and the water bulletin
These updates are not your source for knowing whether there will be a flood. We cannot predict a flood before the situation begins to unfold. There are too many factors at-play.
We may provide information on whether conditions are changing in certain areas that may influence flood potential based on information we have about water levels, flow, snowfall, and any ice jams detected.
Your local government and emergency management officials will use information contained in this report and any other community specific information to help them decide what level of risk a community is at.
They will consider many other observations on-the-ground, and communicate with you about what everyone should do to stay safe.
Get public safety information
Get information about risk in your community, and what you should do:
- Contact/follow on social media/check website: your community government
- Follow: @YourGNWT on Facebook
- Follow: NWT Public Safety Bulletins
- Stay up-to-date: with trusted local news sources
- Learn how to prepare for emergencies: Visit Be Ready for Emergencies
- Get flood preparation tips: Visit Be Ready: For Floods
- Spring Water Outlook
- Annually each April
- View this year's report
- Regional water level and flow updates
- Monthly – year-round
- Weekly May 1 – June 15
- Daily If flood risk is extremely high
When emergency protocols are in-place due to flood danger, the reports will be distributed as part of public safety bulletins from MACA.
Find previous years' updates
- Search: Newsroom
The Government of the Northwest Territories maintains a small network of snow survey stations in the Northwest Territories (NWT) for flood monitoring, wildfire prediction and research purposes.
How they are done
The Government of the Northwest Territories measures the volume of snow at the end of the season (April) at a network of survey sites. Values are converted to a snow-water equivalent (SWE) to enable annual data to be compared from one year to the next. An annual spring bulletin is distributed to various government agencies and industry to inform them of anticipated freshet conditions.