Changes

Bioretention with an [[underdrain]] is a popular choice in areas with 'tighter' soils where infiltration rates are < 15 mm/hr. Including a perforated [[pipe]] in the [[reservoir aggregate]] layer helps to empty the facility between storm events, which is particularly useful in areas with [[low permeability soils]]. The drain discharges to a downstream point, which could be an underground [[infiltration trench]] or [[chamber]] facility. Volume reduction is gained through infiltration and [[evapotranspiration]]. By raising the outlet of the discharge pipe the bottom portion of the BMP can only drain through infiltration, creating an [[Bioretention: Internal_water_storage| internal water storage reservoir]]. This creates a fluctuating anaerobic/aerobic environment which promotes denitrification. Increasing the period of storage has benefits for promoting infiltration, but also improves water quality for catchments impacted with nitrates. A complimentary technique is to include fresh wood mulch in the storage [[Reservoir aggregate| reservoir aggregate]], which fosters denitrifying biological processes.

Bioretention with an [[underdrain]] is a popular choice in areas with 'tighter' soils where infiltration rates are < 15 mm/hr. Including a perforated [[pipe]] in the [[reservoir aggregate]] layer helps to empty the facility between storm events, which is particularly useful in areas with [[low permeability soils]]. The drain discharges to a downstream point, which could be an underground [[infiltration trench]] or [[chamber]] facility. Volume reduction is gained through infiltration and [[evapotranspiration]]. By raising the outlet of the discharge pipe the bottom portion of the BMP can only drain through infiltration, creating an [[Bioretention: Internal_water_storage| internal water storage reservoir]]. This creates a fluctuating anaerobic/aerobic environment which promotes denitrification. Increasing the period of storage has benefits for promoting infiltration, but also improves water quality for catchments impacted with nitrates. A complimentary technique is to include fresh wood mulch in the storage [[Reservoir aggregate| reservoir aggregate]], which fosters denitrifying biological processes.

Where infiltration is entirely impossible, but the design calls for planted landscaping, try a [[stormwater planter]] instead.

Where infiltration is entirely impossible, but the design calls for planted landscaping, try a [[stormwater planter]] instead.