Changes

<p>Infiltration of stormwater into underlying soils is one the priority level 1. mechanisms to achieve MOECC 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 to recharge groundwater supplies.</p>

<p>Infiltration of stormwater into underlying soils is one the priority level 1. mechanisms to achieve MOECC Runoff Volume Control targets.</p>

{{TextBox|1= Infiltration is promoted through a number of LID BMPs:

{{TextBox|1= Infiltration is promoted through a number of LID BMPs:

*[[Infiltration chambers]] (underground)

<li>[[Infiltration chambers]] (underground)</li>

*[[Infiltration trenches]] (underground)

<li>[[Infiltration trenches]] (underground)</li>

*[[Dry ponds]] (surface)

<li>[[Dry ponds]] (surface)</li>

*[[Bioretention cells]] (surface)

<li>[[Bioretention cells]] (surface)</li>

*[[Bioswales]] (surface)

<li>[[Bioswales]] (surface)</li>

}}

</ul>}}

===Constraints===

===Constraints===

Infiltration practices are not recommended:

Infiltration practices are not recommended:

#Where the bedrock is within 1 m below the bottom of the proposed BMP,

<li>Where the bedrock is within 1 m below the bottom of the proposed BMP,</li>

#Where the seasonal high groundwater level comes within 1 m below the bottom of the proposed BMP,<br>Or in areas where increased infiltration will result in elevated groundwater levels, which can be demonstrated to damage critical utilities or private property,

<li>Where the seasonal high groundwater level comes within 1 m below the bottom of the proposed BMP,<br>Or in areas where increased infiltration will result in elevated groundwater levels, which can be demonstrated to damage critical utilities or private property,</li>

#Over swelling clays or unstable sub-soils,

<li>Over swelling clays or unstable sub-soils,</li>

#Over contaminated soils or sites with high risk of contamination from onsite activities,  

<li>Over contaminated soils or sites with high risk of contamination from onsite activities, </li>

#In flood prone areas where the wastewater system is sensitive to groundwater conditions causing sewer backups, and where LID BMPs have been found to be ineffective,

<li>In flood prone areas where the wastewater system is sensitive to groundwater conditions causing sewer backups, and where LID BMPs have been found to be ineffective,</li>

#In areas where the ecology and natural hydrology are dependent upon surface water,

<li>In areas where the ecology and natural hydrology are dependent upon surface water,</li>

#Where prohibitions and/or restrictions exist per approved Source Protection Plans (see MOECC guidance).

<li>Where prohibitions and/or restrictions exist per approved Source Protection Plans (see MOECC guidance).  

===Designing within constraints===

===Designing within constraints===

{{TextBox|1= Infiltration can still be optimized over 'tight' soils with infiltration rates ≤ 15 mm/hr:

{{TextBox|1= Infiltration can still be optimized over 'tight' soils with infiltration rates ≤ 15 mm/hr:

*[[Bioretention: Internal water storage |Bioretention with internal water storage]]8

<li>[[Bioretention: Internal water storage |Bioretention with internal water storage]]</li>

*[[Bioretention:_Partial_infiltration|Partially infiltrating bioretention]]

<li>[[Bioretention:_Partial_infiltration|Partially infiltrating bioretention]]</li>

}}

</ul>}}

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{{TextBox|1= Where infiltration is impossible, LID design alternatives exist which can still capture and retain  stormwater:

{{TextBox|1= Where infiltration is impossible, LID design alternatives exist which can still capture and retain  stormwater:

*[[Bioretention: Non-infiltrating | Bioretention planters]]

<li>[[Bioretention: Non-infiltrating | Bioretention planters]]</li>

*[[Rainwater harvesting]]

<li>[[Rainwater harvesting]]</li>

*[[Green roofs]]

<li>[[Green roofs]]</li>

}}

</ul>}}

===Planning===

===Planning===

<h4>Soil infiltration rate</h4>

<h4>Soil infiltration rate</h4>