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→Space
===Space===
===Space===
*For optimal performance bioretention facilities should receive runoff from between 5 to 20 times their own surface area.
*For optimal performance bioretention facilities should receive runoff from impervious drainage areas 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's total area for bioretention facility placement.
*In the conceptual design stage it is recommended to set aside approximately 10 - 20 % of the contributing drainage area for bioretention facility placement.
*Bioretention cells 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.
*Bioretention cells 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.
*Bioretention can be almost any shape, from having very curvilinear, soft edges with variable depth, to angular, hard-sided and uniform depth.
*Bioretention can be almost any shape, from having very curvilinear, soft edges with variable depth, to angular, hard-sided and uniform depth.
:The maximum width of a facility is determined by the reach of the construction machinery, which must not be tracked into the cell.
:The maximum width of a facility is determined by the reach of the construction machinery, which must not be tracked into the cell.
*Setback from Buildings: A typical four (4) metre setback is recommended from building foundations. If an impermeable liner is used, no setback is needed.
*Setback from Buildings: A typical four (4) metre setback is recommended from building foundations. If an impermeable liner is used, no setback is needed.
*Proximity to Underground Utilities and Overhead wires - consult with local utility companies regards to horizontal and vertical clearance required between storm drains, ditches, and surface water bodies. Further, check whether the future tree canopy height in the bioretention area will not interfere with existing overhead wires
*Proximity to Underground Utilities and Overhead wires - consult with local utility companies regarding horizontal and vertical clearance required between storm drains, ditches, and surface water bodies. Further, check whether the future tree canopy height in the bioretention area will not interfere with existing overhead wires.
The principles of bioretention can be applied in any scenario where planting or vegetation would normally be found.
The principles of bioretention can be applied in any scenario where planting or vegetation would normally be found.