Changes

==Planning considerations==

==Planning considerations==

<h3>Space</h3>  

<h3>Space</h3>  

<p>For optimal performance bioretention facilities should receive runoff from between 5 to 20 times their own surface area. In the conceptual design stage it is recommended to set aside approximately 10 - 20 % of a catchment area to the bioretention facility. Bioretention cell(s) work best when distributed so that no one facility receives runoff from more than 0.8 Ha. Although, there is a trade off to be considered regarding distributed collection and treatment against ease of maintenance.  

For optimal performance bioretention facilities should receive runoff from between 5 to 20 times their own surface area. In the conceptual design stage it is recommended to set aside approximately 10 - 20 % of a catchment area to the bioretention facility. Bioretention cell(s) work best when distributed so that no one facility receives runoff from more than 0.8 Ha. Although, there is a trade off to be considered regarding distributed collection and treatment against ease of maintenance.  

As the aggregates, filter media and geotextiles are flexible, bioretention cells can be almost any shape, from very curving, soft edges with variable depth, to angular,  hard sided and uniform depth. For ease of construction and to ensure that the vegetation has adequate space, cells should be no narrower than 0.6 m at any point. As construction machinery must not be tracked into the cell, the maximum available width is 15 m with access on both sides, or 10 m with access on one side.  This should be confirmed with the contractor.

As the aggregates, filter media and geotextiles are flexible, bioretention cells can be almost any shape, from very curving, soft edges with variable depth, to angular,  hard sided and uniform depth. For ease of construction and to ensure that the vegetation has adequate space, cells should be no narrower than 0.6 m at any point. As construction machinery must not be tracked into the cell, the maximum available width is 15 m with access on both sides, or 10 m with access on one side.  This should be confirmed with the contractor.

{{:Bioretention: Context}}

{{:Bioretention: Context}}

{{:Bioretention: Routing}}

{{:Bioretention: Routing}}

<h3>Design for maintenance</h3>

<h3>Design for maintenance</h3>

==Design==

==Design==

<h3>Sizing</h3>

<h3>Sizing</h3>