Riparian Restoration
Riparian Restoration Citizen Science
At the end of October 2020, Calgary River Valleys (CRV) and small group of volunteers planted approximately 700 sandbar willow stakes along part of the Hanson Ranch stretch of West Nose Creek in Hidden Valley as our 2020 riparian rehabilitation project. We were happy to have some families including children from the nearby neighbourhood join us for the planting day. The riparian restoration was completed that day with the required Covid restrictions, limiting the number of people who could participate, ensuring physical distancing and hygiene protocols were followed.
This project was funded with a grant from the Watershed Resiliency and Restoration Program. We want to extend our thanks to City of Calgary Parks who provided permission to restore this area and facilitated the required permits.
Prior to the planting day, we took the opportunity to incorporate experimental study conditions into the project. The stakes were divided into six groups to compare treatments for rooting success as well as treatments for deterring browsing by animals.
The methods of treating the willows were:
- Approximately half were pre-soaked to promote root growth, and half were not.
- Of each of these halves, a portion were pre-painted with a diluted latex paint mixture on their tips to prevent drying and also deter browsing, and another portion were not.
- Finally, some of the willow stakes were painted after planting with a chili oil and yoghurt mixture to see if animals might be deterred from eating them, and some were left untreated for browsing.
Calgary River Valleys staff returned to the site in May 2021 to observe the conditions of the planted area. Although we had installed some temporary educational signage in the area to let people using the pathway know what was going on in the area, it seems those signs could not withstand our Chinook winds, as they were gone when we returned to the site in May. In addition, we noted that several of the willow stakes planted seemed to have been pushed into the ground by people stepping on them while walking next to the creek edge. It is unlikely that the stakes that were pushed quite far into the ground will sprout. However, we did observe that most of the remaining willows were beginning to bud out. We observed willow stakes budding in each of our treatment conditions. Some were sprouting through the paint itself!
However, we also encountered a number that had been enjoyed by rodents (beavers most likely). We had left some of the off-cuts (trimmed tops of the planted willow stakes) as a “snack” for the beaver in the area, which the beaver seemed to have appreciated. Some planted stakes were also nibbled clean of bark, up to the paint line, which suggests the paint does provide more protection from browsing. We will continue to monitor growth of the willow stakes as well as the comparable outcomes in each of the citizen science experimental conditions.
Also, in 2022 we plan to return to the site to plant approximately 70 pots of native shrubs such as wild rose, wolf willow, buckbrush, and saskatoon bushes. If you, or your family are interested in joining us, please contact us more information.
What is a Riparian Area & What Does It Do?
Riparian is from the Latin root, ripa, meaning bank, i.e. riverbank. A riparian area is the transition zone between the river and the rest of the land. It is a specialized area that has wetter soil than the surrounding land and will support water-loving vegetation. It can vary in width, depending on the width of the river or water body, as well as the slope of the surrounding lands. When the riparian area is healthy with a variety of deep-rooted vegetation it will prevent erosion of the riverbank, improve water quality by filtering run-off from the land and absorbing excess river sediment, reduce river energy during high water events, absorb high water and later release it (like a sponge), and provide excellent habitat for wildlife including shade for fish.
Most experts agree that hard surfaces on the riverbank like large bare rocks or retaining walls are not the best method of reducing the energy of floodwater as these can just rebound the water’s energy and damage another part of the riverbank. Also, the soil in between the rocks or underneath the wall can be washed away by floodwater, defeating its purpose. A better way to reduce the energy of floodwater and ensure the health of the riparian area is to have deep-rooted riparian plants along the river’s edge. However, if the retaining wall or large rocks can’t be removed, it would help to restore the health of the riparian area to plant deep-rooted plants adjacent to a retaining wall and in between the large rocks. During high water and flood events these types of plants help to absorb and reduce the force of the water, stabilize the riverbank, and prevent erosion.
Similar to 2018, in 2019 Calgary River Valleys again completed a “Riverbank Makeover” project with a homeowner who backs onto the Elbow River, with funding support from City of Calgary Water Services. This project is in alignment with the City’s Riparian Action Program, which is designed to improve and maintain the health of river-adjacent areas as well as the quality and quantity of water flowing through Calgary’s rivers and creeks. In 2020 and 2021, we are looking for other landowners who are willing and interested in modifying their river-adjacent land to make it more flood resilient, and to restore its natural functionality. Contact us for more information.
The project had 3 main components:
- Research about people’s knowledge of riparian issues,
- Field work to modify an Elbow River adjacent homeowner’s riparian zone with new vegetation and monitor its success over time, and
- Educate the public about the value and function of riparian zones in our ecosystem.
