How the health of a river is influenced by what's happening on land
Agriculture, land development cause wetland loss in North Saskatchewan watershed
The Prairies Climate Change Project is a joint initiative between CBC Edmonton and CBC Saskatchewan that focuses on weather and our changing climate. Meteorologist Christy Climenhaga brings her expert voice to the conversation to help explain weather phenomena and climate change and how they impact everyday life.
For some residents of northern Alberta and Saskatchewan, the North Saskatchewan River is nothing more than a flowing body of water that starts at the Saskatchewan Glacier in Banff National Park and winds its way northeast.
But it's much more than that. The river is a part of a bigger network of streams and channels that feed into it on its path through the Prairies.
We're talking about a watershed — an area of land that drains into a water body.
Watersheds are complicated, with big differences between regions on the quality and quantity of water. They are also critical to ecosystems and their animal and human populations.
Like many aspects of our environment, watersheds are vulnerable to human activity — from irrigating crops to building cities —that impacts how the land around it is being used.
So how healthy is the North Saskatchewan watershed? And what does its future look like?
How do you measure watershed health?
The North Saskatchewan River begins in the icefields of Banff National Park and continues across Alberta and into Saskatchewan. Just downstream of Prince Albert, Sask., it joins the South Saskatchewan River, and the two become the Saskatchewan River.
That river continues into Manitoba on its path through the Prairies, meeting Lake Winnipeg and eventually draining into Hudson Bay.
In Alberta, the North Saskatchewan watershed includes around 55,000 square kilometres of land; there's another 41,000 in Saskatchewan.
And just like trying to gauge your own health, the well-being of the landscape is affected by many variables.
"There's a number of different indicators, as we would call them, that we can use to measure the health of the watershed," said Michelle Gordy, a watershed planning co-ordinator with the North Saskatchewan Watershed Alliance (NWSA).
The organization monitors the quality and quantity of groundwater, land cover and the impact of populated areas, Gordy said.
"We look at how humans are impacting the watershed. So whether that's through development or things that we do, like recreation, industry, agriculture, you name it."
And as you move toward those populated areas, data shows the health of the watershed suffers.
The health of the watershed
It's been almost 20 years since the NSWA has done a "state of the watershed" report, which takes an in-depth look at its 12 Alberta subwatersheds.
The group is planning to update its reporting in 2024, digging into the variables that affect the watershed's health including groundwater, biological indicators and the impact of land use.
But Gordy said there are some things known from past reports.
"Headwaters were good … most of the rest of [the subwatersheds] were considered fair health," said Gordy.
Two of the watersheds — Strawberry, southwest of Edmonton, and Vermilion, closer to the Saskatchewan border — were considered to be in poor health, based on lost wetland areas, agriculture activity and land development.
"Turning the land from largely wetlands and grasslands to agricultural lands had a huge impact on the health and the functioning of this landscape," said Gordy.
Those changes make the watershed more vulnerable to major stressors — humans and climate change.
"The way that those two interact makes it very, very difficult for [municipalities] to be resilient," she said.
On the Prairies, climate change is expected to bring more flooding and drought.
Gordy said that because of the ways in which the landscape has been altered, the watershed will be less capable of dealing with new extremes brought by climate change.
"You could have a lot of water during a certain part of the season, but if you're not able to store that for use later, then when you have those dry extremes, you're experiencing all of the hardships of drought."
Those same impacts are being felt downstream in the four Saskatchewan subwatersheds, says the North Saskatchewan Basin Council.
Industrial, urban and agricultural activity upstream in Alberta and along the river in Saskatchewan have impacted the health of the watershed, it says.
Although the river in Saskatchewan is considered "relatively healthy," the council said there is evidence of hydrocarbons in the water and higher levels of mercury in the fish.
Edmonton's role in the watershed
Of the roughly 1.7 million people who live in the North Saskatchewan watershed, around 1.5 million live in or around Alberta's capital.
And while Edmonton's land area is small when compared to the watershed on a whole, urban environments — including the small cities in Alberta and Saskatchewan — still have a significant impact, particularly with regard to water quality and land use.
"For the Strawberry [watershed], Edmonton is a huge part of that and there's a lot of built up infrastructure which changes a lot of the function of the watershed as well as the health," said Gordy.
In Edmonton, city-owned utility company Epcor works with a number of partners, including the City of Edmonton and the NSWA, to manage the watershed.
"The water quality that we're seeing in these tributaries is similar to what you'd expect in any urbanized environment across North America," said Steph Neufeld, a watershed manager with Epcor.
Neufeld said when a natural area is changed to impervious surfaces like concrete, it increases what she calls the "flashiness" of the system.
That means that surface water quickly runs off into the river and streams and then subsides, as opposed to being stored in wetlands and groundwater and moving into the system slowly.
"Anything that we would be seeing on the landscape or washing off that landscape would end up in these creek environments and we see that reflected in the water quality," said Neufeld.
She said an example of that comes in the spring, when waterways get a first flush of chloride applied to roads during the winter.
Improving health
In Edmonton, a number of measures have been put in place to manage and improve the health of the watershed, Neufeld said.
"We're moving now to a green infrastructure approach," she said, indicating that such an approach starts with urban hydrology.
That could mean things like adding stormwater ponds to simulate a wetland environment by releasing water slowly to help moderate water quality, she said.
The city is also increasing green spaces and what is called low-impact development. That includes things like bioretention gardens and basins, which look like garden beds but have specific soils and rock to hold and filter water before it enters the stormwater system.
The city has also improved wastewater facilities to moderate water quality. Those initiatives together have improved the health of the North Saskatchewan River as it heads through Edmonton, according to Neufeld.
"It's got high water quality; most of the time you can recreate in it and particularly when it's not a big rain event."
Michelle Gordy adds the Vermilion subwatershed has also taken steps.
"Vermilion was in such poor shape, that's where one of our first subwatershed alliances started," she said.
Municipal leaders and non-profit organizations have come together to try and improve the subwatershed's overall health, including a $1.3 million grant to work with landowners on more than 40 projects to improve conditions on the ground.
Gordy said that could include putting up fencing that gives natural areas time to regenerate by keeping livestock away.
"Cattle, they'll go into the water body and their hooves mess up the banks and then it affects the water quality … so putting up that fence allows for regrowth to happen."
She said the future of the watershed will depend on strategies that are implemented to improve health and restore wetlands.
"We'll monitor over time and then decide how well we're doing, adapt our planning when we have new information and then do another state of the watershed. So it's kind of a cyclical process."
Our planet is changing. So is our journalism. This story is part of a CBC News initiative entitled "Our Changing Planet" to show and explain the effects of climate change. Keep up with the latest news on our Climate and Environment page.
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