Groundwater Recharge Criteria (Rev)
Rev target based on hydrologic soil group and amount of impervious cover
Rev can be considered as part of the water quality volume (WQv)
No Rev for stormwater hotspots
Rev can be achieved by: natural area conservation, grass channels, rooftop disconnection, filter strips, sand filters, bioretention, dry swales, stream buffers, or infiltration.
Goal: maintain pre-development rates of groundwater
recharge to sustain small stream flows and promote
greater use of non-structural practices
Notes:
The intent of the recharge sizing criteria is to maintain groundwater recharge rates at development sites. Very few jurisdictions currently have a recharge requirement, with Massachusetts and Maryland being exceptions.
The groundwater recharge volume will vary with the amount of impervious cover at a site as well as the pre-development hydrologic soil group. If more than one hydrologic soil group is present at a site, a composite recharge volume should be computed based on the proportion of total site area within each hydrologic soil group.
The recharge volume is considered part of the total water quality volume that must be provided at a site.
The recharge volume criteria does not apply to any portion of a site designated as a �stormwater hotspot�
The recharge requirement can be met with non-structural practices such as natural area conservation, stream buffers, and rooftop disconnection, or with structural practices such as bioretention, dry swales, infiltration, or sand filters.