Difference between revisions of "Site considerations"
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!Installation type | !Installation type | ||
!Depth to high water or bedrock (m)<ref>Minimum depth between the base of the facility and the elevation of the seasonally high water table or top of bedrock</ref> | !Depth to high water or bedrock (m)<ref>Minimum depth between the base of the facility and the elevation of the seasonally high water table or top of bedrock</ref> | ||
| − | !Typical ratio of impervious drainage area to permeable facility footprint area | + | !Typical ratio of impervious <br>drainage area to permeable <br>facility footprint area |
!Native soil infiltration rate (mm/hr)<ref>Infiltration rate estimates based on measurements of hydraulic conductivity under field saturated conditions at the proposed location and depth of the practice</ref> | !Native soil infiltration rate (mm/hr)<ref>Infiltration rate estimates based on measurements of hydraulic conductivity under field saturated conditions at the proposed location and depth of the practice</ref> | ||
!Head (m)<ref>Vertical distance between the inlet and outlet of the LID practice</ref> | !Head (m)<ref>Vertical distance between the inlet and outlet of the LID practice</ref> | ||
Revision as of 18:12, 10 March 2022
| Installation type | Depth to high water or bedrock (m)[1] | Typical ratio of impervious drainage area to permeable facility footprint area |
Native soil infiltration rate (mm/hr)[2] | Head (m)[3] | Space % [4] | Slope % [5] | Applicable in pollution hotspots [6] | Set backs | Karst[7] | Wellhead protection area[8] |
|---|---|---|---|---|---|---|---|---|---|---|
| Rain barrels | Not applicable | Not applicable | Not applicable | 1 | 0 | NA | Yes | None | Yes | None |
| Cisterns | Not applicable | Not applicable | Not applicable | 0 | 0 | 0 | Yes | None | Yes | None |
| Roof downspout disconnection | Not applicable | 4:1 or less | Amend if < 15 mm/hr | 0.5 | 5 to 20 | 1 to 5 | Yes | Building Foundation | Yes | None |
| Infiltration trenches or Infiltration chambers | 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 |
No | 2 yr |
| Bioretention | 1 (infiltrating); Not applicable (non-infiltrating) | 5:1 to 15:1 | Underdrain recommended if < 15 mm/hr |
1 to 2 | 5 to 10 | 0 to 2 | No (infiltrating); Yes (non-infiltrating) | 4m- Building Foundation Underground Utilities, Trees, Drinking Water Wellhead Protection Areas |
No (infiltrating); Yes (non-infiltrating) | 2 yr (infiltrating); None (non-infiltrating) |
| Stormwater planters | Not applicable | 5:1 | Not a constraint | 1 to 2 | 2 to 5 | 0 to 2 | No (infiltrating); Yes (non-infiltrating) | Building Foundation, Trees | No (infiltrating); Yes (non-infiltrating) | 2 Yr (infiltrating); None (non-infiltrating) |
| Vegetated filter strips | Not applicable | 5:1 | Amend if < 15 mm/hr | 0 to 1 | 15 to 20 | 1 to 5 | No | None | Yes | None |
| Permeable pavements | 1 (infiltrating); Not applicable (non-infiltrating) | 1:1 | Underdrain recommended if < 15 mm/hr |
0.5 to 1 | 0 | 1 to 5 | No (infiltrating); Yes (non-infiltrating) | 4m-Underground Utilities Drinking Water Wellhead Protection Areas |
No (infiltrating); Yes (non-infiltrating) | 2 Yr (infiltrating); None (non-infiltrating) |
| Enhanced swales (featuring check dams) | 1 | 5:1 to 10:1 | Not applicable | 1 to 3 | 5 to 15 | 0.5 to 6 | No | 4m- Building Foundation Underground Utilities |
No | 2 Yr |
| Bioswales (Dry swales) | 1 (infiltrating); Not applicable (non-infiltrating) | 5:1 to 15:1 | Underdrain recommended if < 15 mm/hr |
1 to 3 | 5 to 10 | 0.5 to 6 | No (infiltrating); Yes (non-infiltrating) | 4m (3m if impermeable liner is used) Building foundation, Underground utilities, Drinking Water Wellhead Protection Areas |
No (infiltrating); Yes (non-infiltrating) | 2 Yr (infiltrating); None (non-infiltrating) |
| Exfiltration trenches | 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 |
No | 2 Yr |
| Stormwater tree trenches | 1 | 5:1 to 15:1 | Underdrain recommended if < 15 mm/hr |
1 to 2 | 5 to 10 | 0 to 2 | No | 4m- Building Foundation Underground Utilities, Drinking Water Wellhead Protection Areas |
No | 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
- ↑ Suitability in areas of karst geologic formations
- ↑ | Drinking Water Source Protection wellhead protection area time of travel