New data sheds light on climate impacts in local watersheds
By Living Lakes Canada
Considered one of North America’s most important water towers, the Canadian Columbia Basin supplies fresh water to millions of people downstream in both Canada and the United States. But climate change is changing the Columbia Basin’s historically steady water supply.
As impacts of heat waves, long periods of drought, out-of-control wildfires, low flows in rivers and streams, and receding glaciers compound year after year, the water security that humans and ecosystems rely on in this region is coming under threat.
To better understand what’s happening to fresh water, more information is needed to allow local communities prepare and plan for change. In response to this need, Living Lakes Canada is building a network of water and climate monitoring stations across the Basin.
The information collected by these stations will help address data gaps in government-run networks, which have seen a decline in monitoring stations in recent decades. As part of the project’s 2022 pilot year, a combination of hydrometric (i.e., water quantity), lake level, and climate monitoring stations were installed in three regions of the Columbia Basin, including the Columbia-Kootenay Headwaters (CKH) and Mid-Columbia Kootenay (MCK).
Since the fall of 2022, 12 new monitoring sites in the CKH region and 14 new monitoring sites in the MCK region have been collecting data. With the first year of data collection drawing to a close, the program has already gained a better understanding of how surface level climate events are impacting important freshwater sources and waterways.
Findings in the Columbia-Kootenay Headwaters Region
Across the CKH, lower-than-average snowpacks, followed by above-average spring air temperatures, contributed to an alarmingly early spring melt. This result was observed at the Bruce and Assiniboine Creeks monitoring stations, where strong snow melt led to peak stream flows and water levels in mid-May.
Rain events in late May and early June maintained surface water levels until a prolonged dry period took hold of the CKH region in mid-June. In addition to sustained high temperatures and low snowpack, the lack of precipitation led to the continued decline of surface water throughout the region.
The streams in the CKH region that are dependent on glacial melt, such as Delphine Creek, were also greatly impacted by this year’s climate extremes. As glaciers melt, water travels beneath the glacier and collects fine glacial sediment. This is what makes mountain rivers and streams cloudy, or turbid. Extreme turbidity and high flows observed at Delphine Creek in July demonstrate the volume of glacial meltwater impacting the creek.
Findings in the Mid-Columbia-Kootenay Region
The MCK region also experienced lower-than-average snowpacks, followed by above-average spring air temperatures, contributing to a very early spring melt and snow-free conditions one month earlier than is typically recorded. This exceptionally early melt was recorded by the project’s hydrometric stations on MacDonald, Caribou, Silverton, Upper Wilson and Fitzstubbs Creeks. Lower than normal precipitation was also recorded during the spring, followed by continued decline in flow for many streams throughout the MCK during the hot and dry summer months.
Streams in the MCK region that are dependent on glacial melt, such as Upper Glacier Creek, were also impacted by this year’s climate extremes. In Upper Glacier Creek, increased flows driven by melting high elevation snow and glacier ice were observed. The unseasonably high spring air temperatures and corresponding streamflow patterns also impacted lake levels across the MCK.
According to the International Kootenay Lake Board of Control, Kootenay Lake water levels peaked one month earlier than historically reported. Lower than average inflows from tributary streams have contributed to a significant decline also seen in Arrow Lakes. The CBWMF program is monitoring tributaries to both of these systems.
As glaciers in the Columbia Basin continue to recede and disappear, continued monitoring will allow us to track the changing contributions from glacially-fed streams to water systems. This information can be used to model other nearby basins that contain glaciers, many of which are important water sources for local residents.
To read the memos summarizing Year 1 data collected up to the end of June in the CKH and MCK regions, visit www.livinglakescanada.ca/cbwmf. A full report of the first year of data will be released early 2024. The preliminary data for all pilot regions in the Columbia Basin Water Monitoring Framework (CBWMF) is publicly available on the Columbia Basin Water Hub database.
Any questions about the project can be directed to Paige Thurston, CBWMF Program Manager, at [email protected].
The CBWMF project is intended to expand upon the valuable monitoring and stewardship work carried out by local stewardship groups, First Nations, provincial agencies, municipal and regional governments, and the private sector, to fill important data gaps across the region’s complex landscapes.
Lead image: Monitoring at Assiniboine Creek. LLC Photo