Changes

Jump to: navigation, search

Swales: TTT

522 bytes removed, 7 months ago
m
no edit summary
{{Clickable button|[[File:TTT.png|400 300 px|link=http://www.sustainabletechnologies.ca/wp/low-impact-development-treatment-train-tool/]]}}
[[File:Swale TTT.png|thumb|Swale element in TTT menu]]
[[File:Weir TTT.png|thumb|Weir elements may be incorporated as checkdamscheck dams for detailed design]]
It is recommended that grass and [[enhanced grass swales]] be modelled using the 'Swale' element in the TTT. A 'swale' has to connect two existing elements within the TTT
For detailed scenarios of enhanced swales, the weir element can be incorporated for each checkdam.
At this time weirs are separate elements, that must be placed within several distinct swales along a single reach.
[[Bioswales]] or dry swales, which have amended filter media, should be modelled as [[Bioretention: TTT|bioretention cells]].
 The alternative is to use the 'enhanced swale' within the LID toolbox, but this incorporates fewer design parameters (and also excludes check damsdoesn't account for infiltration).
{| class="wikitable"
|+A 'swale' as a conveyance element in the TTT (key parameters)
|-
!colspan = "2" style="background: darkcyan; color: white; align = center"|General Info
|-
|Upstream Node||Name of node on the inlet end of the swale (higher elevation)
|-
|Manning's Roughness||Lower numbers indicate less surface obstruction and result in faster flow. <br>
Suggested range for [[Turf|mown grass ]] (dependent on density) 0.03 – 0.06 <ref name = SWMM> Oregon State Univ., Corvallis. Dept. of Civil, Construction and Environmental Engineering.; Environmental Protection Agency, Cincinnati ONRMRL. Storm Water Management Model Reference Manual Volume I Hydrology (Revised). 2016:233.https://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=P100NYRA.txt Accessed August 23, 2017.</ref>
|-
|Upstream Invert (m)||Depth of swale invert above node invert at inlet end of the swale
|Downstream Invert (m)||Depth or elevation of the swale invert above the node invert at the outlet end of the swale
|-
!colspan = "2" style="background: darkcyan; color: white; align = center"|X SectionCross section
|-
|Maximum Depth (m)||Depth of the swale
|Bottom Width (m)||Bottom width of the trapezoidal swale<br> For a triangular channel, enter 0
|-
|Left Side Slope (m/m)||Left side slope (run/rise). [[Enhanced grass swales #Design|Suggested value of 3 or 4 if design permits. [[Enhanced swales]]
|-
|Right Side Slope (m/m)||Right side slope (run/rise). Suggested value of 3 or 4 if design permits.
|-
|Seepage (mm/hour)||Infiltration rate of native (or amended) soil
|} The TTT also includes an 'enhanced swale' element within the LID toolbox. In version 1.0 this element does not incorporate checkdams and doesn't account for any infiltration capacity.
{| class="wikitable"
|+ Parameters for 'enhanced swales' in the LID toolbox of the TTT
|-
!colspan = "2" style="background: darkcyan; color: white; align = center"|Surface
|-
|width = 210px|Berm height (mm)||This is the height of the curb which constrains the overland sheet flow of water. Where the bottom of the slope discharges directly into another LID facility without impedance, the value is 0.
|-
|Surface roughness (Manning’s n)||Lower numbers indicate less surface obstruction and result in faster flow. <br>
Suggested range for [[Turf|mown grass ]] (dependent on density) 0.03 – 0.06 <ref name = SWMM> Oregon State Univ., Corvallis. Dept. of Civil, Construction and Environmental Engineering.; Environmental Protection Agency, Cincinnati ONRMRL. Storm Water Management Model Reference Manual Volume I Hydrology (Revised). 2016:233.https://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=P100NYRA.txt Accessed August 23, 2017.</ref>
|-
|Surface slope (%)||If the slope > 3%, consider using small use [[CheckdamsCheck dams]] or weirs to permit create temporary ponding, increase infiltration, and slow flow to reduce erosion.
|-
|Swale side slopes (run/rise)||[[Enhanced grass swales #Design|Suggested value of 3 or 4 if design permits [[Enhanced swales.]]
|}
 
[[Category: modeling]]

Navigation menu