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→Life Cycle Costs
===Site Topography===
===Site Topography===
Contributing slopes should be between 1 to 5%. Swale longitudinal slopes may range from 0.5 to 6% (this prevents ponding while providing residence time and preventing erosion). On slopes steeper than 3%, check dams should be used. Check the [https://s3-ca-central-1.amazonaws.com/trcaca/app/uploads/2020/01/30145157/ESC-Guide-for-Urban-Construction_FINAL.pdf| Erosion and Sediment Control Guide For Urban Construction] for further details.
Contributing slopes should be between 1 to 5%. Swale longitudinal slopes may range from 0.5 to 6% (this prevents ponding while providing residence time and preventing erosion). On slopes steeper than 3%, check dams should be used. Check the [https://sustainabletechnologies.ca/home/erosion-and-sediment-control/esc-guide/ Erosion and Sediment Control Guide]
===Water Table===
===Water Table===
*Erosion protection such as river stone or riprap will be required to dissipate the energy from incoming concentrated flow.
*Erosion protection such as river stone or riprap will be required to dissipate the energy from incoming concentrated flow.
*The channel must be vegetated immediately after [[grading]]. Preferably, the swale should be planted in the spring so that the vegetation can become established with minimal irrigation.
*The channel must be vegetated immediately after [[grading]]. Preferably, the swale should be planted in the spring so that the vegetation can become established with minimal irrigation.
==Inspection and Maintenance==
Maintenance requirements for [[enhanced swales|enhanced grass swales]], and swales is similar to vegetated filter strips and typically involve a low level of activity after [[vegetation]] becomes established. [[Grass]] channel maintenance procedures are already in place at many municipal public works and transportation departments. These procedures should be compared to the recommendations provided on the [[Inspection and Maintenance: Enhanced Swales]] page to assure that the infiltration and water quality
benefits of enhanced grass swales are preserved.
Routine roadside ditch maintenance practices such as scraping and re-grading should be avoided at swale locations. Vehicles should not be parked or driven on grass swales. For routine mowing, the lightest possible mowing equipment should be used to prevent soil compaction.
For swales located on private property, the property owner, resident or manager is responsible for maintenance as outlined in a legally binding maintenance agreement. Roadside
swales in residential areas generally receive routine maintenance from homeowners who should be advised regarding recommended maintenance activities and ensure they do not build anything within or on the channel of the swale which could result in flooding or pooling on theirs or their neighbours' properties.
<br>
Take a look at the [[Inspection and Maintenance: Enhanced Swales]] page by clicking below for further details about proper inspection and maintenance practices:
{{Clickable button|[[File:Cover Photo swales.PNG|150 px|link=https://wiki.sustainabletechnologies.ca/index.php title=Inspection_and_Maintenance:_Enhanced_Swales&action=edit]]}}
==Construction Considerations==
==Construction Considerations==
===Water Balance===
===Water Balance===
Recent research indicates that a conservative runoff reduction rate of 10 to 20% can be used depending on whether soils fall in [[Soil groups| hydrologic soil groups A/B or C/D,]] respectively. The runoff reduction rates can be doubled if the native soils on which the swale is located have been tilled to a depth of 300 mm and amended with compost to achieve an organic content of between 8 and 15% by weight or 30 to 40% by volume. The mai ncontributing factors that influence runoff reduction rates for swales are:
Recent research indicates that a conservative runoff reduction rate of 10 to 20% can be used depending on whether soils fall in [[Soil groups| hydrologic soil groups A/B or C/D,]] respectively. The runoff reduction rates can be doubled if the native soils on which the swale is located have been tilled to a depth of 300 mm and amended with compost to achieve an organic content of between 8 and 15% by weight or 30 to 40% by volume. The main contributing factors that influence runoff reduction rates for swales are:
* Native [[Soil groups|soil]] types
* Native [[Soil groups|soil]] types
* [[Grading|Slope]]
* [[Grading|Slope]]
|-
|-
| colspan="2" style="text-align: center;" |'''<u><span title="Note:This estimate is provided only for the purpose of initial screening of LID practices suitable for achieving stormwater management objectives and targets. Performance of individual facilities will vary depending on site specific contexts and facility design parameters and should be estimated as part of the design process and submitted with other documentation for review by the approval authority" >Runoff Reduction Estimate*</span></u>'''
| colspan="2" style="text-align: center;" |'''<u><span title="Note:This estimate is provided only for the purpose of initial screening of LID practices suitable for achieving stormwater management objectives and targets. Performance of individual facilities will vary depending on site specific contexts and facility design parameters and should be estimated as part of the design process and submitted with other documentation for review by the approval authority" >Runoff Reduction Estimate*</span></u>'''
|colspan="2" style="text-align: center;" |'''46% on [[Soil groups|HSG A or B soils]];'''
|colspan="2" style="text-align: center;" |'''45% on [[Soil groups|HSG A or B soils]];'''
'''10% on [[Soil groups|HSG C or D soils]]'''
'''10% on [[Soil groups|HSG C or D soils]]'''
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==Life Cycle Costs==
To learn about Life Cycle Costs associated with this practice (i.e. Pre-construction, Excavation, Materials & Installation, Project Management, Overhead, Inspection and Maintenance, Rehabilitation and other associated costs), visit the [[Enhanced Swales: Life Cycle Costs]] page to view a cost estimate. Alternatively you can use the [https://sustainabletechnologies.ca/lid-lcct/ STEP's Low Impact Development Life Cycle Costing Tool (LID LCCT)] to generate cost estimates customized to your own LID stormwater design project specifications.
Take a look at the [[Enhanced Swales: Life Cycle Costs]] page by clicking below for further details:
{{Clickable button|[[File:Construction Breakdown EnhancedSwales Full Infil.PNG|150 px|link=https://wiki.sustainabletechnologies.ca/wiki/Enhanced_Swales:_Life_Cycle_Costs]]}}
==External Links==
==External Links==