Water quantity in the Peace sub-basin has undergone moderate change. Observations by Indigenous communities and scientists suggest that ice is less thick, with earlier break-ups and later freeze-up dates in many waterbodies, particularly in the lower Peace. Less snow was reported in the lower Peace (the northern and eastern regions of the sub-basin), while there is more snow accumulation in the upper Peace (the western and southern regions). Water levels in lakes, rivers, and creeks are more variable, although communities have generally observed lower levels than in the past. Late winter flows have increased in some small tributaries while freshet flows in Peace River have decreased. These changes are likely the result of a combination of flow regulation on the Peace River by the W.A.C. Bennett Dam and the effects of climate change. Changes in water quantity threaten to further disrupt the aquatic ecosystem health and the ability for Indigenous communities to practice a traditional way of life in the sub-basin.
The following table summarizes the availability of information for each Water Quantity indicator.
Signs and Signals
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
Limited 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. Many studies on ice cover and ice jams on the Peace River.
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
Long-term data sets available from some Water Survey of Canada stations; data from four stations on the Peace River and four stations in major tributaries were analyzed.
Local observations and oral histories of temperature, precipitation normal and extremes over time
No information found.
Temperature, precipitation normals and extremes over time
Data available from weather stations in the basin, analyses completed. Other sources are Pacific Climate Impacts Consortium (PCIC), Climate BC and Climate WNA (Western North America).
Not assigned a Sign or Signal
Number of water licenses, purpose, volume allocated, and volume actually used vs. water flow / level; Water demand from various sectors, including dams, agriculture, oil and gas, etc., trends in water use over time
Water Licenses available but not retrieved for this report. Reports available.
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; Few = 1-3 locations; Several = 4 or more locations
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
Changes in ice quality, the presence and break-up of ice jams and reductions in snow have been observed in the lower Peace sub-basin, while snow mass increased in the south-western portion of the sub-basin.
Freeze-up trend analysis from 1971 to 2002 indicates that freeze-up has been occurring at higher river stages since the construction the of W.A.C. Bennett Dam. This results in fewer ice-jam floods because it increases the required stage for ice breakup to occur and promotes more thermal ice-breakup events. These act to reduce the likelihood of mechanical break-up events, which promote ice-jams and related flooding.,
Ice-jam flooding in the lower Peace only occurs when the discharge at Peace Point is > 4000 m3/s; mean monthly flows exceeded this threshold in 13 of 58 years on record. The freshet maximum monthly discharge decreased between 1972 and 2017 by 13.5 m3/s per year. However, this change is not statistically significant and may be attributed to natural variability.
The Peace-Athabasca Delta has received less water from flooding since the W.A.C. Bennett Dam regulation. Both climate trends and the impacts of regulation have influenced the reduced incidence of ice-jam flooding delivering water to the Delta. Analysis of one research team indicates that regulation played a greater role in this result than climate trends (climate alone would have reduced flood frequency by 21%, while the total observed reduction is 57%). Another research team, however, has presented paleolimnological evidence that drying of the Delta and ice-jam flood frequency is driven by climate variability.,
Change in Average March Snow Mass (as Snow Water Equivalent, in mm/decade) in the Peace sub-basin 1980 to 2015. Positive (light green, yellow, orange, red) values indicate increases in snow mass, negative (dark green) values indicate declines in snow mass.
Water Flows & Levels
Declines in water levels across the basin and increased flooding in some areas have been observed by Indigenous communities in the Peace sub-basin. Streamflow records indicate earlier spring freshets and lower summer streamflows, and some lake levels have declined.
Many Indigenous communities have observed a marked decline in water levels in the Peace sub-basin in the past several decades. Trend analyses on lake level data from 1972 to 2018 indicate that lake level changes are site specific, with decreasing trends in Mamawi Lake in the Peace Athabasca Delta and no significant trends in Lake Claire in the Peace Athabasca Delta and Sturgeon Lake near Valleyview (this study, see figure). Members of Treaty 8 First Nations from BC and Alberta have reported that water levels across the sub-basin are low and affecting fish spawning habitat in tributaries of the Peace River. In the lower Peace, members from Mikisew Cree First Nation and Athabasca Chipewyan First Nation have reported shallower water conditions throughout the Peace-Athabasca Delta, which poses challenges for boat access and travel. Lower water levels are typically attributed to an increase in surface water diversion for industrial activity in recent years, particularly hydroelectric and hydraulic fracturing activities. The “drying of the Delta” is a widely reported phenomenon and the relative importance of climate change and hydroelectric development in driving this change has been subject to much debate (see Athabasca sub-basin assessment).
The Kelly Lake Métis have similarly observed lower levels in rivers and lakes in the upper Peace including Hythe River, Beaverlodge River, and Horse Lake. According to Kelly Lake Métis elders, many creeks within their traditional territory are running dry in late May rather than late July or early August, much earlier than in the past. Similarly, a declining trend in the lake levels from 1983 to 2008 has been recorded in Saskatoon Lake near Grande Prairie, but an updated analysis of lake level data would be required to verify recent trends.
Freshet and early summer (May, June) flows on the Peace River have decreased since the W.A.C. Bennet Dam has been operational (1972). June flows decreased by 1.2 % and 0.9% annually (9 and 15 m3/s, respectively) in the Peace River at Hudson’s Hope and at Taylor, and summer (July) flows have decreased further downstream at Peace River at Peace Point by 1.0 % annually (29 m3/s). Tributaries to the Peace River have also had apparent (although not statistically significant) decreases in freshet flows, indicating that these decreasing trends may be a regional response to a shifting climate signal.
Analysis of Water Survey of Canada flow data showed that late winter flow has increased in some small tributaries. For example, the Parsnip River above Misinchinka River had February flows increase by 1.02 % per year. This trend is likely linked to increased winter temperatures contributing to more winter snow melt.
Peak instantaneous flows remain unchanged over the period of record across the sub-basin.
Air temperatures increased from 1948 to 2016, with largest increases recorded in winter. Decreases in annual winter precipitation largely outweigh precipitation increases in spring, summer and fall.
Temperature and Precipitation trends in the Peace Sub-basin (1948 – 2016 for temperature, 1948 – 2012 for precipitation). From: Bonsal et al. in review
Temperature Change (°C)
Precipitation Change (%)
Note: Spring: Mar-Apr-May, Summer: Jun-Jul-Aug, Fall: Sep-Oct-Nov, Winter: Dec-Jan-Feb
Water is withdrawn from surface and groundwater sources for commercial, municipal and industrial use across the Peace sub-basin. While total annual allocation represents a small portion of annual Peace River flows and a portion of water is returned, local impacts to smaller water courses are less well understood.