Marsh land bridge (Photo by NCC)

Marsh land bridge (Photo by NCC)

Using new practices to protect wetlands

Land bridge on Marsh property (Photo by NCC)

Land bridge on Marsh property (Photo by NCC)

One of the key challenges ranchers face is access to clean water: a necessity for the health of both grasslands and livestock. Cows require access to water. If given the opportunity, they will spend most of their time in and around riparian (riverbank) areas. Over time, this will degrade the health of the natural area and negatively impact the water quality.

The Marsh property, located in the Waterton Park Front in Alberta's southern foothills, contains a spring that feeds into Little Crooked Creek. To protect the riparian areas around the spring from destruction by cattle, the Nature Conservancy of Canada (NCC) decided to explore a new and creative way to keep the cows out of the water.

Cows and Fish (Alberta Riparian Habitat Management Society) came out to the property to assess the health of the riparian areas on the property, as well as downstream. Three different sections of the creek were assessed. Two sections were rated healthy; however, one section was categorized as healthy but with problems.

This caused NCC to begin exploring solutions to ensure the health of these natural areas.

Our partner organization, the Alberta Conservation Association, suggested fencing off the stream. However, rancher Scott Hanson, who holds the grazing lease on the property, was concerned about the safety of his cattle. The Waterton Park Front is one of the few regions left in Alberta that still hosts a full complement of native species and predators, such as bear, cougar and wolf, that roam this area. These predators will hunt cattle, often trapping them in a corner and with no safe way to escape.

The project team decided to build a land bridge across the stream, allowing the cattle to cross from one section of the pasture to the other in safety while maintaining the health of the surrounding natural area. The remainder of the stream would be fenced off, protecting the riparian area and in turn preserving its water quality.

This was accomplished by using a tool that NCC had not used before: a large modular culvert covered in packed soil called Enviro Span. Typically, the installation of a standard culvert requires heavy equipment and machinery to be in the stream, which disturbs much of the area in and around the stream. Over time, traditional culverts can break down and release heavy metal oxides into the stream, compromising the quality of the water. This can have long-term negative effects on the living organisms in that system.

Both the Department of Fisheries and Oceans and Alberta Environment and Parks have regulations that limit the amount of activity or disturbance to waterways, in order to protect their ecological values. However, Enviro Span is an excellent alternative to standard culvert systems, offering a significantly lower footprint while still providing a functional stream crossing. It is essentially a bottomless culvert that has the ability to curve and follow the natural stream bed. As a result, there is little to no disturbance to the overall stream.

Enviro Span is also used as land bridges for resource roads that carry heavy loads, such as off-highway mining and logging machinery. As a result, it is considered safe to bear the weight of cattle. (To see how this process is accomplished, visit the Enviro Span website.)

The bridge materials were funded by Watershed Resiliency and Restoration Program, a Government of Alberta program that funds the improvement of watershed functions and increases resiliency to floods and droughts. 

The fencing and the bridge were completed in 2017. They will now allow the section in which the stream was degraded to regain its health and regrow native vegetation, without being disturbed by cattle.

This property is being used to support the Jenkins ranching operation, following the loss of much of the forage on the Jenkins property during the 2017 Kenow wildfire. Future plans for the Marsh property include maintaining and enhancing the ecological integrity of the land as well as to continuing to graze the area in a sustainable manner.

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