Provincial highway threatens rare native grassland ecosystem
Saskatoon, SK, is a vibrant and growing prairie city within an agricultural landscape. But in and around Saskatoon there are some enchanting and ever-changing natural sites, gems that provide a glimpse into pre-settlement landscapes. These areas include complex and diverse combinations of native plant and animal communities, housed and fed in a mosaic of diverse habitats influenced by erosion, grazing, and fire. Some of these areas have fescue and mixed grassland prairie —globally the most threatened ecosystem, and regionally an increasingly rare occurrence (at 5% of original extent for fescue, and 9% to 15% for mixed).
At 26km long, the Northeast Swale is one of the largest of these grassland sites: a lumpy yet endearing swath of rolling hills and wetlands, on land over which an ancient river once flowed. There are actually two swales in the northeast of Saskatoon, separated by an upland plateau soon to become residential housing. Of the nearly 2,800 hectares of the whole swale, only 300 ha is within City limits, the rest being private land in the RM of Corman Park. There is currently no formal protection of the Swales, within or beyond City limits, although various options for designation of the Small and Northeast Swales are being reviewed by City council. Since they are quite similar in terms of plant and animal communities, and very close, we refer to them together as the Swales, and most discussions of the Northeast Swale can be assumed to include the Small Swale.
Considered too rocky to farm and too costly to develop, the Swales were grazed and occasionally mined for gravel. Now, many people recognize the Swales’ ridges, knolls, and dips as ecologically valuable and regionally vital habitat for a wide range of species, including some that are endangered. Recent reports from regular visitors suggest that some species not seen for years are starting to return!
Migratory and resident birds, mule and white-tailed deer, badger (provincially vulnerable, S3), and northern leopard frog — a federally ranked species of special concern — rely on the Swales. There are also a number of leks — mating dance grounds for the sharp-tailed grouse, our provincial bird.
While the Swales are in reasonably good health (in most parts), they are nevertheless subject to worsening pressures of suburban sprawl, and face an uncertain future with a major highway slated to go through both. Furthermore, the City of Saskatoon recently built the North Commuter Parkway (2018), a road and bridge that connects residential and industrial nodes, through both Swales. Guided by previously established design principles, the placement of the road tried to avoid disturbing high quality habitat. But, just like any other road, this one inevitably produces a number of negative impacts on the surrounding ecosystem, such as
- Vehicle-animal collisions
- Spread of invasive species
- Road salt, oil, and other pollutants
- Habitat fragmentation
The latest threat to the long-term sustainability of the Swales is actually one that has been around for a long time: the Saskatoon Freeway. Previously known as the Perimeter Highway, this “ring road” has been lurking in the background since 1992. A number of follow-up traffic and functional planning studies “validated” the route for those old projections of urban growth and traffic flow, but what about the environment?
It turns out that environmental impacts weren’t seriously considered until 2004, when a thorough account was made of species and habitat through which the Freeway would run.
Even then, there was no discussion of moving the proposed corridor, only of tweaking the location and type of interchanges. These decisions were largely driven by efficiency in traffic models, with marginal consideration for environmental impacts. Furthermore, previous stakeholder consultations focused on (at the time) rural landowners, and even the environmental concerns raised by residents were merely noted but not meaningfully addressed.
A lot has changed since the original traffic modelling, stakeholder consultations, and public engagement. Now the Freeway will cut through publicly-owned city lands, impacting green infrastructure that the city, province, and ultimately tax payers have funded and continue to fund. The Saskatoon projected in decades-old transportation planning is not the Saskatoon of today, and neither are the residents. Results from the original public engagements are not necessarily representative of the current social values of — and landowner interests in — the Swales. There has been no serious discussion about the implications of climate change, biodiversity, or conservation in any of the studies to this point.
The Northeast Swale is a highly valued landscape, for humans and wildlife alike. Just like the species that rely on it, the Swales must be protected, and their connection to other natural areas improved and extended. The city has grown since the original corridor was drawn, and stakeholder engagement for the original corridor can no longer be considered relevant to contemporary social values and landowner interests. The Swales are already facing a variety of stressors, and this highway presents yet another one.
- We need to prepare for an uncertain climate future, protect the precious few examples of native prairie that remain, and give more weight to the environment in provincial planning and development.
- We need to stop spending taxpayer money on planning for the current alignment, which threatens four lanes of high-speed traffic through sensitive habitat and wildlife corridors.
- We need to ensure that future provincial and municipal developments are well-informed by public values and ecological science, so that environmental protection can be achieved through avoidance instead of betting on mitigation.
- We need to know that, as residents of the city and the province, our voices are heard, so that the City of Saskatoon and the Government of Saskatchewan will recognize and invest in the many public health benefits and ecological goods that are associated with biodiversity and natural areas.
The impacts on natural areas from roads and other land uses include:
* edge effects, such as the spread of alien invasive species where natural areas meet urban areas or roads;
* fragmentation, where roads or developments create barriers to the movement of water, animals, and plant genetic material across the landscape;
* “islanding” or enclosure, where development entirely surrounds the natural area by removing connectivity.
Written by Warrick Baijius
geographer and PhD candidate at the University of Saskatchewan, with a keen interest in conservation and resource management politics