Wetlands

Wetlands fed by stormwater at Kortright Farm, Vaughan ON

Overview

Wetlands are an ideal technology for:

• Text A
• Text B

Types of Constructed Wetland

Type A	Type B	Type C
Surface water	Minimal Any surface flow can be slowed with check dams	Ponding is encouraged with check dams
Soil	Filter media required	Amendment preferable when possible
Underdrain	Common	Uncommon
Maintenance	Medium to high	Low
Stormwater benefit	High	Moderate
Biodiversity benefit	Increased with native planting	Typically lower

Performance

STEP (under previous name SWAMP) conducted their own research into the performance of stormwater wetlands, the project page and report can be viewed here.

Gallery

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  Wetlands on the Rouge River, Toronto ON. Photo credit: Vlad Litvinov (flickr)

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  Emergent wetland vegetation supported by stormwater runoff at Kino Environmental Restoration Project. Photo by Matthew Grabau, US Fish and Wildlife Service

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  Azalea Park, Charlottesville VA - "This side of the park, formerly located along a runoff channel that led into Moore's Creek, has been converted into a wetland which supports a surprising amount of insect and amphibian life." -Credit and Photo: Scott Clark (certhia on Flickr).

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  Walberswick Mill sluice, part of the water level control and coastal defence infrastructure within the marshes, UK

A vegetated area such as a bog, fen, marsh, or swamp, where the soil or root zone is saturated for part of the year.

Structures constructed of a non-erosive material, such as suitably sized aggregate, wood, gabions, riprap, or concrete; used to slow runoff water. Can be employed in practices such as bioswales and enhanced grass swales.

The engineered soil component of bioretention cell or dry swale designs, typically with a high rate of infiltration and designed to retain contaminants through filtration and adsorption to particles.

A perforated pipe used to assist the draining of soils.

Sustainable Technologies Evaluation Program

Shallow, constructed pools that capture stormwater and allow for the growth of characteristic wetland vegetation.

The portion of water precipitated onto a catchment area, which then flows as surface discharge from the catchment area past a specified point.

Water from rain, snow melt, or irrigation that flows over the land surface.