Site considerations
Revision as of 15:14, 31 January 2019 by Jenny Hill (talk | contribs) (Jenny Hill moved page LID Site Criteria and Constraints to LID site criteria and constraints: Decaps)
| LID Stormwater Management Practice | Depth to High Water or Bedrock (m)[1] | Typical Ratio of Impervious Drainage Area to Treatment Facility Area |
Native Soil Infiltration Rate (mm/hr)[2] | Head (m)[3] | Space % [4] | Slope % [5] | Applicable in Pollution Hotspots [6] | Set Backs | Water Table [7] | Wellhead Protection Area[8] |
|---|---|---|---|---|---|---|---|---|---|---|
| Rain Barrel | Not applicable | [5 to 50 m2] | Not applicable | 1 | 0 | NA | Yes | None | None | None |
| Cistern | Not applicable | 1:1 | Not applicable | 0 | 0 | 0 | Yes | None | None | None |
| Roof Downspout Disconnection | Not applicable | [5 to 100 m2] | Amend if < 15 mm/hr | 0.5 | 5 to 20 | 1 to 5 | Yes | Building Foundation | None | None |
| Soakaway, Infiltration Trench or Chamber | 1 | 5:1 to 20:1 | Not a constraint | 1 to 2 | 0 to 1 | <15 % | No | 4m- Building Foundation Underground Utilities, Trees, Drinking Water Wellhead Protection Areas |
1 m | 2 yr |
| Bioretention | 1 | 5:1 to 15:1 | Underdrain required if < 15 mm/hr |
1 to 2 | 5 to 10 | 0 to 2 | No | 4m- Building Foundation Underground Utilities, Trees, Drinking Water Wellhead Protection Areas |
1 m | 2 yr |
| Biofilter (Filtration only Bioretention Design) | Not applicable | 5:1 | Not applicable | 1 to 2 | 2 to 5 | 0 to 2 | Yes | Building Foundation, Trees | None | None |
| Vegetated Filter Strip | 1 | 5:1 | Amend if < 15 mm/hr | 0 to 1 | 15 to 20 | 1 to 5 | No | None | None | None |
| Permeable Pavement | 1 | 1:1 to 1.2:1 | Underdrain Required if < 15 mm/hr |
0.5 to 1 | 0 | 1 to 5 | No | 4m-Underground Utilities Drinking Water Wellhead Protection Areas |
1 m | 2 Yr |
| Enhanced Grass Swale | 1 | 5:1 to 10:1 | Not applicable | 1 to 3 | 5 to 15 | 0.5 to 6 | No | 4m- Building Foundation Underground Utilities |
1 m | None |
| Dry Swale (Bioswale) | 1 | 5:1 to 15:1 | Underdrain Required if < 15 mm/hr |
1 to 3 | 5 to 10 | 0.5 to 6 | No | 4m (3m if impermeable liner is used)Building foundation, Underground utilities, drinking water wellhead protection areas |
1 m | 2 Yr |
| Perforated Pipe System | 1 | 5:1 to 10:1 | Not a constraint | 1 to 3 | 0 | < 15% | No | 4m- Building Foundation Underground Utilities, Trees, Drinking Water Wellhead Protection Areas |
1 m | 2 Yr |
- ↑ Minimum depth between the base of the facility and the elevation of the seasonally high water table or top of bedrock
- ↑ Infiltration rate estimates based on measurements of hydraulic conductivity under field saturated conditions at the proposed location and depth of the practice
- ↑ Vertical distance between the inlet and outlet of the LID practice
- ↑ Percent of open pervious land on the site that is required for the LID practice
- ↑ Slope at the LID practice location
- ↑ Suitable in pollution hot spots or runoff source areas where land uses or activities have the potential to generate highly contaminated runoff
- ↑ Separated from the seasonally high water table or top of bedrock elevation
- ↑ |Time-of-travel within wellhead protection areas