A historic lack of snowfall in the western U.S. is sparking worries about water scarcity and increased wildfire risks in the upcoming summer. A recent study from Canada indicates that this situation may indicate a prolonged pattern that could jeopardize water resources for millions of people nationwide.
Snow cover levels in the western U.S. are currently significantly lower than the usual amounts for this time of year, hitting the lowest levels ever documented since monitoring began with NASA’s Terra satellite in 2001. Researchers from Concordia University in Montreal observed a decrease in snow accumulation and water content in parts of western Canada from 2000 to 2019, possibly influenced by a warming climate.
While the affected regions make up only a small portion of the country, they impact the headwaters of major rivers in the Canadian Rockies. The study reveals slight decreases in other areas of southern Canada, although these decreases are not individually statistically significant.
Ali Nazemi, one of the study’s authors and an associate professor of engineering at Concordia, noted that 14 out of 25 major drainage basins in Canada are experiencing some form of impact from the declining snow levels. This decline in snowpack has far-reaching implications, affecting municipal water systems, agriculture, lake water levels, shipping, and the risk of wildfires in Canadian forests.
The insufficient snow is disrupting the ski season at prominent resorts in the region. Several ski slopes in British Columbia have had to halt operations or reduce activities due to the lack of snow and warm weather. Vail Resorts, which owns ski facilities across Canada and the U.S., reports one of the worst early-season snowfalls at its western U.S. resorts. Vancouver is experiencing its first snowless winter in 43 years.
According to Alejandro Flores, a geosciences professor at Boise State University in Idaho, the diminished snowfall is not due to a lack of precipitation this year but rather a shift from snow to rain, termed a “wet snow drought.” This transition is consistent with expectations in a warming climate, where warmer temperatures cause precipitation that would typically fall as snow to turn into rain.
The snow cover in mountainous regions acts as a natural water storage system, releasing water during warmer months when it is needed for various purposes. However, the reduction in snowpack could lead to water stress in forests earlier in the year, raising the risk of wildfires across North American forests.
Nazemi’s team developed a new metric called “snow water availability” to measure the water content in the snowpack accurately. By analyzing data from 2000 to 2019 using satellite technology, they identified the Okanagan in British Columbia, the Assiniboine-Red River basin in Manitoba, and the Saskatchewan River basin as the most impacted watersheds. The declines in snow water availability may reduce flows in crucial rivers like the Fraser River and the St. Lawrence River, impacting water supply and hydropower for millions of people.
Nazemi emphasized that past instances of declining snow cover have affected water security significantly. For instance, in 2015, a substantial drop in winter snowpack in the Rocky Mountains led to severe drought conditions in central British Columbia, necessitating water restrictions and fishing bans on the Okanagan River. The trend of declining snow levels could pose increasing challenges in the future, requiring a reevaluation of water management strategies.
Further research is needed to determine the speed and severity of potential water shortages in the coming years, as experts like Kate Hale stress the importance of studying these impacts to facilitate necessary adaptations in water resource management practices.
