Difference between revisions of "Swales"

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This article is about planted installations designed to capture <strong>and convey</strong> surface runoff through an engineered soil with subterranean infrastructure.  
This article is about installations designed to capture and convey surface runoff along a vegetated channel.  
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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 are filled with engineered soil and a water storage layer of coarse gravel material.  <br>
<ul>
They are sometimes referred to as 'dry swales', 'vegetated swales', 'water quality swales' or 'inline bioretention'.   
<li><strong>Bioswales</strong> are sometimes referred to as 'dry swales', 'vegetated swales', 'water quality swales' or 'inline bioretention'.  
  <li><strong>Enhanced Grass Swales</strong> are an alternative with lower maintenance requirements, but generally lower stormwater mangement potential. </li>
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<caption><strong>Types of Swales</strong></caption>
<caption><strong>Types of Swales</strong></caption>
<tr class ='success'><th>Property</th><th>Bioswale</th><th>Enhanced Grass Swale</th></tr>
<tr class ='success'><th>Property</th><th>Bioswale</th><th>Enhanced Grass Swale</th></tr>
<tr><td>Surface water</td><td>Minimal<br>Any surface flow can be slowed with check dams</td><td>Ponding encouraged with check dams</td></tr>
<tr><td>Surface water</td><td>Minimal<br>Any surface flow can be slowed with check dams</td><td>Ponding is encouraged with check dams</td></tr>
<tr><td>Engineered soil</td><td>Biomedia required</td><td>Amendment preferable when possible</td></tr>
<tr><td>Engineered soil</td><td>Biomedia required</td><td>Amendment preferable when possible</td></tr>
<tr><td>Udnerdrain</td><td>Common</td><td>Uncommon</td></tr>
<tr><td>Underdrain</td><td>Common</td><td>Uncommon</td></tr>
<tr><td>Maintenance</td><td>Medium to high</td><td>Low</td></tr>
<tr><td>Maintenance</td><td>Medium to high</td><td>Low</td></tr>
<tr><td>Stormwater benefit</td><td>High</td><td>Medium</td></tr>
<tr><td>Stormwater benefit</td><td>High</td><td>Medium</td></tr>
<tr><td>Biodiversity benefit</td><td>Increased with native planting</td><td>Lower</td></tr>
<tr><td>Biodiversity benefit</td><td>Increased with native planting</td><td>Lower</td></tr>
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<p><strong>The fundamental components of a swale are:</strong>
<p><strong>The fundamental components of a swale are:</strong>

Revision as of 20:01, 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.

  • Bioswales are sometimes referred to as 'dry swales', 'vegetated swales', 'water quality swales' or 'inline bioretention'.
  • Enhanced Grass Swales are an alternative with lower maintenance requirements, but generally lower stormwater mangement potential.

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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