Low impact development

EPCOR is working to reduce the risk of flooding in Edmonton. Our plans include the use of green stormwater infrastructure, which includes Low Impact Development (LID) techniques. LID is a site development technique that aims to mimic natural processes to manage stormwater runoff close to its source. Examples of LID features include rain gardens, bioretention basins, box planters, soil cells, and absorbent landscaping.

LID installations incorporate plants, soils and natural processes to capture stormwater runoff. Stormwater enters the LID installation and flows into the soil layer with the ability to capture, and filter stormwater. Specially selected plants then absorb the water or it evaporates.

Benefits of LID

The benefits of LID vary by scale and include several common advantages:

Flood reduction: In smaller rain events, the amount of rain can be entirely absorbed by the plants and soil in the LID installation. In bigger storms, the LID installation slows the speed of the water entering the underground pipes (where applicable), which can help reduce the peak and control the flow, thereby reducing the flooding in our neighbourhoods.
Rainfall absorption: Distributing vegetated LID techniques across the landscape allows rainfall to soak into the ground near where it falls. This can help reduce localized flooding, as during smaller rainfall events, the rain can be absorbed by plants and soil in the LID.
Vegetation: Preserving, replanting, or adding vegetation allows more water to be used by vegetation.
Pollutant filtration: The soils and plants in an LID installation filter pollutants and stop them from entering the underground pipes. In neighbourhoods with a combined sewer system, the frequency of untreated water discharged into the river will be reduced.
Green space: LID installations provide green spaces that can help our bees and wildlife.
Air quality improvement: Plants incorporated into the LID installation absorb pollution from the air and reduce the amount of heat that is reflected off the pavement.

Rebates for LID installations

EPCOR is offering rebates on LID installations like rain gardens, box planters, soil cells, and absorbent landscaping on private property.

Check out the RainWise Rebate Program to learn more.

EPCOR's LID installations

EPCOR has identified and included five types of LID installations within EPCOR’s Design and Construction Standards that will benefit our sewer system and the environment:

Bioretention gardens look like a typical flower or shrub bed; however, these gardens have specially blended soils and a storage component to filter and hold water during and after a rainfall. These gardens work by allowing rainwater to enter the garden and then be filtered by the soil and plants.

This process slows water from entering the stormwater system and helps mitigate localized flooding. Bioretention gardens have no pipes and are not connected to the stormwater system.

Bioretention basins look like a typical flower or shrub bed, but underneath have specially blended soils and rock layers to hold water during and after a rainfall. These basins have their own inlet and a perforated pipe where water is collected, allowing rainwater to enter the basin and be filtered by the soil before going to the stormwater system.

This process slows water from entering the stormwater system and helps mitigate localized flooding.

Box planters look similar to a traditional flower box, but have specially blended soils and rock layers, along with plants, to hold water during and after a rainfall.

This process slows water from entering the stormwater system and helps mitigate localized flooding. Box planters can look very different depending where they are installed but are typically used in urban areas.

Soil cells are plastic milk crate-like structures, that contain specially blended soils, designed to be installed beneath sidewalks and roads. Once the soil cells are installed, you often can’t tell they are there. These soil cells have their own inlet and a perforated pipe where water is collected, allowing rainwater to enter the soil cells to encourage plant root growth to help hold water during and after a rainfall.

The water is then filtered by the soil before going to the stormwater system. This process slows water from entering the stormwater system and helps mitigate localized flooding.

Absorbent landscaping looks similar to grassed areas and can include other vegetation or trees. The landscaped area contains a surface inlet and outlet and may contain a small depression; the area is built with deeper topsoil, to hold water during and after a rainfall.

This process slows water from entering the stormwater system and helps mitigate localized flooding. Absorbent landscaped areas have no pipes and are not connected to the stormwater system.

Over the next few years, you will start to see more LID installations around Edmonton. If you would like to see LID in action, visit the Braithwaite Park, Imagine Jasper or the alley space located at 10319 83 Avenue, locally known as "Back Street", where LID has been incorporated into the functionality, landscaping, and aesthetics at each location. The North Glenora Community Playground is a great example of a rain garden.

If you're interested in incorporating LID in your own property, we suggest installing a rain garden. Rain gardens provide you with more than beautiful landscaping. If you have experienced flooding on your property or want to help Edmonton adapt to climate change, rain gardens may be a good option. A rain garden, like all LID installations, helps to reduce the risk of property flooding and can add aesthetic value.

Tools and resources

EPCOR has developed a number of tools and resources to help with the designing and installing LID:

Low impact development best mangement practices design guide
A list of native species, that are well adapted to the climatic conditions in Edmonton. Note that these are not the only species that can be incorporated into LID, in some cases, it may be appropriate to select a(n) ornamental or naturalized species
Design standards for the implementation of LID in Edmonton