Difference between revisions of "Filter strips: TTT"
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|Surface roughness (Manning’s n)||Lower numbers indicate less surface obstruction and result in faster flow. Suggested range for 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 roughness (Manning’s n)||Lower numbers indicate less surface obstruction and result in faster flow. Suggested range for 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> | ||
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− | |Surface slope (%)||If the slope > 3%, consider using level spreaders to reduce erosion of the surface under high flow velocities. | + | |Surface slope (%)||If the slope > 3%, consider using [[level spreaders]] to reduce erosion of the surface under high flow velocities. |
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!colspan = "2" style="background: darkcyan; color: white; align = center"|Soil (native underlying soil, or amended topsoil) | !colspan = "2" style="background: darkcyan; color: white; align = center"|Soil (native underlying soil, or amended topsoil) |
Revision as of 02:51, 6 November 2017
Surface | |
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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. Suggested range for mown grass (dependent on density) 0.03 – 0.06 [1] |
Surface slope (%) | If the slope > 3%, consider using level spreaders to reduce erosion of the surface under high flow velocities. |
Soil (native underlying soil, or amended topsoil) | |
Thickness (mm) | If topsoil has been amended Absorbent landscapes |
Porosity (fraction) | Suggest range 0.35 – 0.4, unless otherwise tested |
Field capacity (fraction) | Will vary according to native or amended topsoil[1] |
Wilting point (fraction) | |
Conductivity (mm/hr) | |
Conductivity slope | |
Suction head (mm) | |
Design drawdown time (hrs) | ? |
- ↑ 1.0 1.1 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.