By Jeannine Goehing, Office of the Chief Scientist
Have you ever noticed the changing colors of the water in the North Saskatchewan River – from clear teal to murky brown? Looking over the river from his ninth floor office in downtown Edmonton, Dr. Craig Emmerton points out that, under certain conditions, the river’s color reveals its glacial origin. “Under low-flow conditions, the river’s mountain water signature with its glacial fine sediment influenced teal color is visible in Edmonton – some 400 kilometers away from the Rocky Mountains,” he says. In contrast, high-flow conditions during spring-melt and storm events bring about the murky appearance, the river’s water and coarser sediment signature from lower elevation landscapes downstream of the mountains, he explains.
With a total length of 1,287 kilometers, the North Saskatchewan River is Canada’s 12th longest river, discharging an average 210 cubic meters of water, the equivalent of 1,500 bathtubs, every second in Edmonton, and providing drinking water for over 800,000 people in the Edmonton Capital Region alone.
With a common goal of protecting the source of our drinking water supply, Alberta Environment and Parks, EPCOR, the North Saskatchewan Watershed Alliance and the City of Edmonton, have teamed up on a four-year long project to improve our knowledge of the health and water quality of the North Saskatchewan River.
Journey through Alberta
“One of the beauties for me of the North Saskatchewan River is the transition from its pristine headwaters in the mountains through agriculturally-dominated areas all the way to the grasslands along the Saskatchewan border,” says project lead Dr. Cristina Buendia-Fores, Aquatic Scientist with the Environmental Monitoring and Science Division at Alberta Environment and Parks. “It seems like a totally different river.”
Originating from the Saskatchewan Glacier in Banff National Park and fed year-round by snowmelt, rain events and glacial meltwater from the Rocky Mountains, the North Saskatchewan River picks up speed and volume on its way through the eastern slopes of the Rockies. Moving east, it first winds its way through steeply sloping, then rolling hills of the Foothills Region. From there, it leisurely continues downstream in a well-defined valley through Alberta’s Parkland, where it is an essential water source for municipal, industrial and agricultural users.
Along its 885 kilometer long journey through Alberta, the North Saskatchewan River flows through five distinct natural regions, six rural counties and one of Alberta’s largest populated watersheds, the Edmonton Capital Region. On its way towards the Alberta-Saskatchewan border, the river passes through prairies before joining its southern namesake – the South Saskatchewan River. Final destination: Hudson Bay.
Along this journey, numerous tributaries –– smaller freshwater streams that flow into the larger river (the mainstem) –– feed into the North Saskatchewan River for a total length of 3,600 kilometers. It’s these tributaries, and their effects on the water quality and quantity of the mainstem, that are drawing the research team’s full attention.
Quest for improved data
The water quality of the North Saskatchewan River and its tributaries reflects the combined effects of human activities, including industry, agriculture and urban centers, and natural processes, such as changes in precipitation patterns or the erosion of different soils and geological material. For example, much of the mainstem and tributaries upstream of Edmonton contain easily erodible silts and clays that can cause the murky (turbid) appearance of the river during high-flow periods. This in turn affects the water treatment process EPCOR uses to ensure clean and healthy drinking water to Albertans.
Historically, water quality and quantity data collection has primarily focused on the mainstem of the North Saskatchewan River and a few of its mid-reach tributaries. “The problem is that we don’t fully understand the source, transport and fate of contaminants, or which tributaries are the main drivers of the patterns observed in the mainstem,” Cristina explains.
The solution: turning the spotlight on major tributaries along the entire length of the river basin, including the western headwater streams. The advantages of collecting data from representative tributaries are many. “Monitoring tributaries will improve our knowledge of source water supplies and contaminant sources. These data will help us target management actions to specific, disturbed tributaries that negatively impact water quality of the mainstem or protect those areas less impaired by human activities,” Cristina continues.
Originally from Spain, a country facing long-lasting water scarcity problems, Cristina has always been fascinated with river ecosystems and water resource management. She studied sediment and water management in regulated rivers before serving as Technical Advisor on the North Saskatchewan Watershed Alliance. She then joined the four-year partnership between EPCOR and the Government of Alberta as project lead under the direction of Dr. John Orwin, Executive Director at Alberta Environment and Parks, who designed the monitoring program.
Project co-lead Craig joined Alberta Environment and Parks as Watershed Scientist after spending over 15 years studying lakes and rivers across Canada, from one of the world’s largest arctic marine deltas –– the Mackenzie Delta –– to the world’s largest high arctic lake.
Under their joint leadership, a team of four technicians conducts sampling at 19 representative tributaries and four mainstem locations. Since November 2018, the team has installed hydrometric stations –– five by five feet-sized shacks that are solar-powered and equipped with sensors –– to collect water quality and quantity data in near-real time. The team also repeatedly dips bottles, literally, at the same locations to analyze major water quality parameters, including minerals, nutrients, metals and dissolved organic matter – a parameter that influences water color and has financial implications for water treatment processes.
Additional studies will reveal how aquatic species are faring and provide information on the overall health of the aquatic ecosystem. These studies look at a range of indicators, from sediment and water quality, to the physical condition of the river and the state of biological communities.
Path towards improved water quality
For Cristina, the path towards improved water quality is clear.
“We need science and monitoring to understand what is driving water quality and water quantity and to support management,” she says.
Although research takes time and resources, the benefits are many. Ultimately, the long-term monitoring initiative of the North Saskatchewan River and its major tributaries will inform decision makers about risks to the mainstem and help maintain high source water quality for Albertans.
“Identifying areas that need stabilization or riparian rehabilitation and making actual improvements on the ground could ultimately be the most rewarding part of this program,” Craig adds.
For him, this project presents an exciting opportunity to work on another great Canadian waterway, “It’s amazing to see the diversity of the rivers and lakes across this province and country and I’m excited to see more parts of the North Saskatchewan River over the next four years.”
Access to near real-time data
Near real-time river flow data from this project can be viewed and downloaded on the Alberta River Basins website.