Difference between revisions of "Swales"

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m (Jenny Hill moved page Bioswales to Swales: To amalgamate the two types of swales)
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===Overview===
===Overview===
<p>Swales are linear landscape features consisting of a drainage channel with gently sloping sides. Underground they may be filled with engineered soil and/or contain a water storage layer of coarse gravel material.  <br>
<p>Swales are linear landscape features consisting of a drainage channel with gently sloping sides. Underground they may be filled with engineered soil and/or contain a water storage layer of coarse gravel material.  Two variations on a basic swale are recommended as low impact development strategies, although using a combination design of both may increase the benefits:<br>
<strong>Bioswales</strong> are sometimes referred to as 'dry swales', 'vegetated swales', 'water quality swales' or 'inline bioretention'. <br>
<strong>Bioswales</strong> are sometimes referred to as 'dry swales', 'vegetated swales', 'water quality swales' or 'inline bioretention'. This type of structure is similar to a [[Bioretention Cells|bioretention cell]] but with a linear shape (typically >2:1 )<br>
<strong>Enhanced Grass Swales</strong> are a lower maintenance alternative, but generally have lower stormwater management potential.  
<strong>Enhanced Grass Swales</strong> are a lower maintenance alternative, but generally have lower stormwater management potential. The enhancement over a basic grass swale is in the addition of check dams to slow flow and create small puddles of water which can infiltrate the underlying soil. 
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Revision as of 20:20, 22 June 2017

This article is about installations designed to capture and convey surface runoff along a vegetated channel.

Overview[edit]

Swales are linear landscape features consisting of a drainage channel with gently sloping sides. Underground they may be filled with engineered soil and/or contain a water storage layer of coarse gravel material. Two variations on a basic swale are recommended as low impact development strategies, although using a combination design of both may increase the benefits:
Bioswales are sometimes referred to as 'dry swales', 'vegetated swales', 'water quality swales' or 'inline bioretention'. This type of structure is similar to a bioretention cell but with a linear shape (typically >2:1 )
Enhanced Grass Swales are a lower maintenance alternative, but generally have lower stormwater management potential. The enhancement over a basic grass swale is in the addition of check dams to slow flow and create small puddles of water which can infiltrate the underlying soil.

Swales are an ideal technology for:

  • Sites with long linear landscaped areas, such as parking lots
  • Connecting with one or more other types of LID
Types of Swales
PropertyBioswaleEnhanced Grass Swale
Surface waterMinimal
Any surface flow can be slowed with check dams
Ponding is encouraged with check dams
Engineered soilBiomedia requiredAmendment preferable when possible
UnderdrainCommonUncommon
MaintenanceMedium to highLow
Stormwater benefitHighMedium
Biodiversity benefitIncreased with native plantingLower

The fundamental components of a swale are:

  • graded channel
  • planting

Additional components may include:

  • Biomedia - an engineered soil mix
  • Planting
  • Underdrain with clean out and inspection ports
  • Impermeable membrane to prevent infiltration to soils below
  • Check dams

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Planning Considerations[edit]

Planning Content

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Design[edit]

Design Content

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Performance[edit]

Performance Content

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Incentives and Credits[edit]

In Ontario

City of Mississauga
The City of Mississauga has a stormwater management credit program which includes RWH as one of their recommended site strategies[1].

LEED BD + C v. 4

SITES v.2


See Also[edit]


External Links[edit]


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