Nine Types of Stormwater Management Facilities Used in Quebec

What is a stormwater management facility?

Stormwater management facilities may be designed to collect, store, convey and treat stormwater or runoff.

Stormwater management facilities are usually built to offset the loss of pervious ground caused by buildings, roads, parking lots, etc. Many of these facilities also improve water quality before the water is returned to the environment.

Main types of stormwater management facilities

1. Retention pond
2. Retention and infiltration chambers
3. Infiltration trench
4. Rain garden
5. Vegetated swale
6. Bioretention basin
7. Constructed wetland
8. Grass pavers and permeable pavements
9. Pretreatment structures

Below, we offer a quick overview of these nine types of stormwater management facilities. Green roofs, which are also stormwater management facilities, are not covered here. For more information, we recommend the Régie du bâtiment du Québec’s page on building green roofs.

1. Retention pond

Retention ponds are designed to temporarily store stormwater before releasing it at a controlled rate into a watercourse. They are the most commonly used stormwater management facilities in Quebec. They are generally built in low-density residential developments or in industrial or commercial areas.

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2. Retention and infiltration chambers

Retention and infiltration chambers are made of open-bottom plastic arches, sometimes recycled and recyclable. Covering the arches with backfill stone creates, in a sense, underground basins. Retention and infiltration chambers can be installed under parking lots, sports fields or in residential developments, among other places.

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3. Infiltration trench

An infiltration trench is a long channel excavated in permeable soil and filled either with infiltration chambers (open-bottom plastic arches) or with a perforated drain surrounded by clean stone. This facility promotes the infiltration of stormwater from gutters or runoff flowing across the property.

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4. Rain garden

Rain gardens take advantage of the property’s grading, which directs rainwater toward them. They intercept runoff and promote infiltration into the soil on the property. Careful plant selection is particularly important in their design.

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5. Vegetated swale

Vegetated swales are mainly used in commercial, institutional and municipal settings. They are wide, shallow ditches (8 to 10 in., or 20 to 25 cm, deep) planted with various native plant species. A vegetated swale slows runoff, promoting particle settling and stormwater infiltration.

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6. Bioretention basin

Bioretention basins are similar to rain gardens. Used for larger-scale applications than residential properties, they intercept runoff from parking lots or roadways to allow for its retention, infiltration and controlled release.

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7. Constructed wetland

A constructed wetland is an artificial basin that purifies water laden with residues and pollutants before releasing it to a downstream watercourse. The plants selected for the wetland stimulate microbial activity and oxygenate the water, and their root systems can capture certain pollutants.

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8. Grass pavers and permeable pavements

Grass pavers, permeable pavers and permeable pavements can turn large impervious surfaces (such as a driveway or a public parking lot) into permeable or semi-permeable surfaces. Part of the stormwater infiltrates through the pavement into the native soil. The excess is discharged either to the municipal storm sewer system or to an open or underground retention facility.

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9. Pretreatment structures

Pretreatment structures remove sediment, floating debris, oils and grease from stormwater and runoff. They are used either at the end of the network to treat water before it is discharged to the receiving watercourse, or upstream of an infiltration facility (infiltration chamber, dry retention pond, bioretention basin, etc.).

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Consult Avizo’s drainage professionals to make sure the stormwater and runoff from your urban development project are managed optimally.