Reducing erosion, flooding, and pollution while improving fish and wildlife habitat
We’re working to reduce the pollution in our rivers, creeks, and streams that comes from stormwater runoff, while at the same time improving wildlife habitat and protecting stream banks from erosion.
We’ve got a big plan that is nearing completion called the Integrated Stormwater Management Plan (ISMP), however many of the best practices for stormwater management are already being incorporated into our capital works and operational programs.
The Keith Road bridge replacement project is a great example of the improvements we’ve made.
Stormwater management at the new Keith Road Bridge
The old fashioned approach to stormwater management was to direct rainwater runoff from paved surfaces like roads and sidewalks through a network of curbs, gutters, and pipes, into nearby creeks and streams.
This approach results in significant impacts to watershed health, including degradation of habitat, streambank erosion and deterioration of water quality.
So, when designing the new Keith Road Bridge, we jumped on the opportunity to include innovative green infrastructure that captures, slows down, filters, and re-directs the runoff, simulating natural conditions and reducing impacts to nearby waterways.
Additionally, we enhanced the riparian area along Lynn Creek in the vicinity of the bridge.
Here are examples of the green infrastructure techniques we used:
A bioswale is a landscaped area that collects, slows down, and filters stormwater runoff. At Keith Road bridge, the bioswale removes roadway pollutants, such as gasoline, motor oil and rubber, which improves the water quality in Lynn Creek and allows more of the stormwater to soak into the ground.
A flat curb allows water to run off paved surfaces and onto natural surfaces, such as stones and grass. This slows down the water and allows it to soak into the soil at a more natural rate, while filtering out some pollutants. Flat curbs were used in the new parking lot at Bridgman Park.
Catch basin dispersion drains
The catch basins by the bridge collect runoff from paved surfaces that have curbs and gutters, and includes a dispersion drain that allows water to soak into the ground below the catch basin. Once the ground is saturated, stormwater flows into the piped system and is carried away. This helps avoid flooding.
Riparian zone protection
A riparian zone is the interface between the land and a river, creek, or stream. At Bridgman and Seylynn Parks, we protected this valuable wildlife habitat by relocating creek side walking trails 15m from the edge of the creek, restoring creek banks along the decommissioned trails, installing 950m of new cedar fencing to reduce erosion on streambanks, and replacing invasive plant species with native plants.
The vegetation in riparian zones helps fish and the aquatic ecosystems by providing shade to keep water cooler, creating habitat for fish to hide in, promoting vegetation growth to provide nutrients, and providing erosion protection with root structures. As part of the Keith Road Bridge project, we planted more than 465 trees and 19,000 shrubs to restore the forest understory and riparian habitat.
Next steps for the Integrated Stormwater Management Plan
Staff are currently finalizing the new ISMP. Once completed, the next step will be to start implementing the recommendations it contains, in order to meet nine key stormwater management objectives.
- Maximize base flows
- Maximize fish populations
- Maximize riparian ecosystems
- Maximize social-ecological connection
- Maximize sense of safety and security
- Minimize impacts on First Nation traditional use activities
- Maximize natural assets
- Minimize damage to infrastructure
- Minimize institutional costs and conflict
You can learn about all nine objectives, plus get additional plan details, on our website.
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