City of Edmonton, Alberta
Kennedale End-of-Pipe Constructed Wetland
End-of-pipe treatment wetlands are a relatively new, innovative and cost-effective way to treat stormwater runoff from older, built-out communities that would otherwise discharge street runoff directly to rivers. Edmonton's watershed monitoring program demonstrated that over 80 per cent of the suspended solids discharged to the North Saskatchewan River are from the city’s storm sewer system.
As a result, a Stormwater Quality Strategy (SWQS) and Action Plan were developed to improve local watershed health. The SWQS examined potential stormwater quality improvement projects and identified possible sites for improving stormwater quality and reducing pollutants discharged to the river. The Kennedale end-of-pipe constructed wetland realized multiple cost-effective benefits for pollutant load reduction, watershed protection, and improved site aesthetics.
The project was cost-effective because land (a former gravel pit in Hermitage Park) was readily available, and it provided added value by improving the park for users and creating more natural habitat. While Edmonton has a number of other stormwater management facilities — some of which also provide partial treatment — they have been built primarily for flood prevention. The Kennedale facility is the city's first constructed wetland built exclusively for stormwater treatment and river protection. It is expected to operate indefinitely and will allow the city to continue to develop and grow as an urban centre without impairing local watershed health.
- 70% of annual stormwater volume through the city’s largest sewer trunk will be treated
- 1,100 kg (44%) of suspended solids are removed each day
- Wetland provides additional bird, amphibian and aquatic habitat