Innovative Stormwater Management Practices
Bioswales
What is a bioswale?
Bioswales are vegetated open channels specifically designed to attenuate and treat storm water runoff for a defined water volume. Similar to open ditches, bioswales convey storm water volumes from a source point (where rain falls) to a discharge point. Unlike an open ditch, they are designed to intentionally slow down the velocity of storm water, provide opportunities for infiltration, and facilitate water quality improvement through special vegetation and plantings that remove pollutants from storm water.
Where is the bioswale in Greenbury?
The bioswale is located along the centre median of the main roadway through the neighbourhood, collecting and filtering storm water runoff from the roadway.
Why is the bioswale green?
- Slows the velocity of runoff and lowers runoff volumes: The vegetation and length of the bioswale system results in a longer route for the water to reach the storm water management facility, allowing time for pollutant filtering and infiltration. The increased level of infiltration recharges the water table
- Increases infiltration: While water moves slowly along the path of the bioswale towards the storm water management facility, the vegetation and sub soils within the bioswale absorb some of the water, also providing a permeable surface for the water to infiltrate into the ground
- Water cleansing: plantings within the bioswale clean pollutants such as heavy metals from the water
Constructed Wetland Storm Water Facility
What is a constructed wetland storm water management facility?
Like a conventional storm water management facility, a constructed wetland storm water management facility will detain water to reduce flooding/peak flows after a rainfall event. However, a constructed wetland facility design with shallow vegetated channels and shallow marshes within the facility helps to slow down water, thereby causing sediment and other particles to settle within the pond. Vegetation (macrophyres) in channels and marsh areas also helps to strip nutrients and some chemicals from water.
Where is the constructed wetland stormwater management facility in Greenbury?
The facility is located in the north part of the neighbourhood along the main roadway.
Why is the constructed wetland storm water management facility green?
- Less maintenance and energy use: Minimization of the amount of mown grass by using a ‘naturalized landscape’ in the facility will reduce the ongoing energy use associated with grass cutting as well as reduce the potential use of fertilizers, pesticides, etc which might enter the drainage system
- Water cleansing: Increased contact of storm water flows with plant materials benefits the environment by cleansing the water of contaminants and pollutants prior to discharge
- Passive recreation: Residents will have the opportunity to walk around the facility, and spend time in seating areas. This provides with opportunities for passive recreation (e.g. bird watching)
- Habitat: The wetland facility will provide habitat for waterfowl, small mammals, amphibians and insects
