Water Management and Monitoring

Snow Monitoring

The Department of Environment and Climate Change (ECC) conducts on-the-ground snow surveys at the end of winter every year across the territory to inform flood monitoring, wildfire prediction, year-to-year variability and research. The amount of snow received over winter is an important variable that influences water levels and flow on lakes and rivers during spring break up.  The summary values from these surveys are included in the NWT Spring Water Level Outlook each year. 

Snow survey work in the Snare River basin is completed in partnership with Northwest Territories Power Corporation.

ECC also compiles snow data collected at climate stations operated by Environment and Climate Change Canada. These data are published between October and March in monthly NWT Water Monitoring Bulletins.

How are snow surveys completed?

At each snow survey location, a snow sample is taken at 10 pre-determined points. Two measurements are recorded at each point:  snow depth and snow water equivalent (SWE). SWE refers to the depth of water (in millimetres) that would be produced if that snow sample was melted. Heavy and wet snow has a higher SWE than light and fluffy snow. The SWE value is obtained by weighing the snow using a calibrated snow scale. The average density of the snowpack at each point is calculated by dividing SWE by the depth of the snow.

SWE values for each of the 10 points are averaged into one SWE value for that snow survey location. This average value is what is included in the summary data.

Where can I find the data?

A summary of snow survey data can be found in each year’s NWT Spring Water Level Outlook. This document also includes snow survey data from neighbouring jurisdictions for shared basins (e.g. Slave River, Hay River, Liard River and Peel River) 

Recent years’ snow survey summary data can also be viewed and downloaded in table format using the Government of the Northwest Territories Open Data Portal.

Latest updates

The Water Monitoring and Stewardship Division distributes monthly NWT Water Monitoring Bulletins.  These bulletins provide an update of water flow and level data at select NWT Hydrometric Network gauge stations across the Northwest Territories.  During the winter months, these also include monthly precipitation data for six communities in the NWT. 

You can also subscribe to our distribution list to receive the NWT Spring Water Level Outlook and monthly NWT Water Monitoring Bulletins by email.  Email us at nwtwaters@gov.nt.ca.

Environment and Climate Change snow survey locations