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| Infiltration of stormwater into underlying soils is one mechanism to achieving MECP [[runoff volume control targets]]. In many areas of Ontario, where municipal supplies of potable water are drawn from aquifers, it's also an important mechanism for groundwater recharge. | | Infiltration of stormwater into underlying native subgrade soils is one mechanism to achieving MECP [[runoff volume control targets]]. In many areas of Ontario, where municipal and private drinking water supplies are drawn from aquifers, it's also an important mechanism for groundwater recharge. |
| {{textbox|Drainage via infiltration to underlying native subgrade soil can be achieved through a number of LID BMP types: | | {{textbox|Drainage via infiltration be achieved through a number of LID BMP types: |
| *[[Infiltration chambers]] (underground) | | *[[Infiltration chambers]] (underground) |
| *[[Infiltration trenches]] (underground) | | *[[Infiltration trenches]] (underground) |
| *[[Exfiltration trenches| Exfiltration systems]] (underground) | | *[[Exfiltration trenches| Exfiltration systems]] (underground) |
| *[[Bioretention]] (surface) | | *[[Bioretention]] (surface, full- or partial-infiltration design variations) |
| *[[Bioswales]] (surface) | | *[[Bioswales]] (surface, full- or partial-infiltration design variations) |
| *[[Stormwater Tree Trenches]] (surface) | | *[[Permeable pavements| Permeable pavements]] (surface, full- or partial-infiltration design variations) |
| *[[Permeable pavements| Permeable pavements]] (surface) | | *[[Stormwater Tree Trenches|Stormwater tree trenches]] (surface) |
| | *[[Enhanced swales]] featuring check dams (surface) |
| *[[Dry ponds]] or infiltration basins (surface) | | *[[Dry ponds]] or infiltration basins (surface) |
| }} | | }} |
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| #where prohibitions and/or restrictions exist per approved Drinking Water Source Protection Plans (e.g. should not be used to treat pavement runoff within 2 year time of travel wellhead protection areas; see MOECC guidance). | | #where prohibitions and/or restrictions exist per approved Drinking Water Source Protection Plans (e.g. should not be used to treat pavement runoff within 2 year time of travel wellhead protection areas; see MOECC guidance). |
| <br> | | <br> |
| | See [[Site considerations]] for further guidance on potential site constraints and LID facility type selection and design considerations. |
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| | ===Designing with constraints=== |
| | {{textbox|Infiltration facilities can be effective on low permeability soils with infiltration rates ≤ 15 mm/hr: |
| | *See [[Underdrains| underdrains]] and |
| | *Results from STEP studies of infiltration facilities located on [[low permeability soils]] in Ontario. |
| Infiltration facilities should be designed with modifications where: | | Infiltration facilities should be designed with modifications where: |
| #the underlying bedrock is within 1 m below the bottom of the proposed BMP, or | | #the underlying bedrock is within 1 m below the bottom of the proposed BMP, or |
| #the seasonal high groundwater level (i.e. water table) comes within 1 m below the bottom of the proposed BMP. | | #the seasonal high groundwater level (i.e. water table) comes within 1 m below the bottom of the proposed BMP. |
| ===Designing with constraints===
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| {{textbox|Infiltration can still be optimized over 'tight' soils with infiltration rates ≤ 15 mm/hr:
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| *See [[Underdrains| underdrains]] for [[Bioretention| bioretention]] and [[Trees| tree pits, trenches and soil cells]], and
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| *Results from STEP studies of infiltration practices on [[low permeability soils]]
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| }}
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| {{textbox|Where infiltration is impossible, LID design alternatives exist which can still capture and retain stormwater:
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| *[[Stormwater planters]]
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| *[[Rainwater harvesting]]
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| *[[Green roofs]]
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| *[[Blue roofs]]
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| }} | | }} |
| | {{:Groundwater}} |
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| ==Planning== | | ==Planning== |
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| ==See also== | | ==See also== |
| *[[Groundwater]] | | *[[Site considerations]] |
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| [[category:Infiltration]] | | [[category:Infiltration]] |