Water quantity in the Mackenzie Great Bear sub-basin has undergone moderate change overall. Based on Indigenous and scientific observations, the sub-basin is subject to significant reductions in snow and ice cover, slightly earlier river ice break-up, and reduced spring river peak flows since the 1970s. These are likely linked to significant changes in climate over the past few decades, such as increased temperatures, particularly in winter. Human water use within the sub-basin has negligible impacts on water quantity due to the small population and large water yield in this sub-basin. Annual average river flows have mostly been stable, but winter and spring river flows have increased by up to 2% per year. The observed changes have potential to impact aquatic ecosystems and the ability for Indigenous communities to practice traditional land uses in the Mackenzie Great Bear sub-basin.
The following table summarizes the availability of information for each Water Quantity indicator.
Indigenous Knowledge Information and Data
Indigenous Knowledge Availability 1
Science Information and Data
Science Data Availability2
Snow and Ice
Local observations and oral histories of changes in snow quality, ice thickness, presence and break up of ice jams
Some observations from few locations.
Available modeling information / stats on snow quality, ice thickness, presence and break up of ice jams
Snow data and analyses available from many weather stations. Low availability of ice data; limited ice monitoring.
Water Flows and Levels
Local observations and oral histories of changing flow / water levels in rivers / lakes and aquifers over time
Many observations from several locations.
Seasonal statistics including changes in flow / water levels in rivers / lakes and aquifers over time
Data available from many Water Survey of Canada stations; analyzed six representative sites across the basin.
Local observations and oral histories of temperature, precipitation normals and extremes over time
Limited observations from few locations.
Temperature, precipitation normals and extremes over time
Data available from many weather stations in the basin, analyses was provided.
Not assigned to a Sign or Signal
Number of water licenses, purpose, volume allocated, and volume used vs. water flow / level; Water demand from various sectors, including dams, agriculture, oil and gas, etc., trends in water use over time
Water Licences issued by Water Boards, not collected for this version.
1 Qualifiers for the availability of local and Indigenous Knowledge observations in publicly available sources: Limited = 1-2 observations; Some = 3-4 observations; Many = 5 or more observations
2 Qualifiers for the availability of science data in publicly available sources: Low = Individual studies or locations; Many = Network of monitoring stations across the basin
Snow & Ice
Reduced snowpack, shorter duration of ice cover, and earlier ice break-ups in some rivers and lakes have been observed in some locations in the Mackenzie Great Bear sub-basin.
Snow mass trends were derived using a multi-dataset approach described in Mudryk et al. 2020, and provided by Environment and Climate Change Canada.
Water Flows & Levels
Changes in seasonal flow patterns and lower water levels in some rivers and lakes have been observed in the Mackenzie Great Bear sub-basin.
Warmer air temperatures and more variability in precipitation have been recorded in the Mackenzie Great Bear sub-basin.
Sub-basin (as defined in Bonsal et al 2020)
Temperature Change (°C)
Note: Spring: Mar-Apr-May, Summer: Jun-Jul-Aug, Fall: Sep-Oct-Nov, Winter: Dec-Jan-Feb
Precipitation Change (%)
The Mackenzie Great Bear sub-basin has a small population and minimal industrial activity, and thus minimal water demand on the large water supply.