A low impact development (LID) technique for reducing the impact of stormwater is to "disconnect" impervious areas by routing runoff to a vegetated filter strip. This will promote infiltration, sediment deposition, and filtration of pollutants.
This water quality control is similar to vegetative filter strips described in Section 1.6.7.B of the Environmental Criteria Manual . It will however typically be smaller in order to fit into spaces too small for a full-sized water quality control, but still large enough to provide some treatment. The amount of water quality credit will vary with the size of the filter strip and its drainage area characteristics (size and impervious cover). Vegetative filter strips for treatment of disconnected impervious cover can provide partial treatment equivalent to a sedimentation/filtration system but are not acceptable as a primary method in Barton Springs Zone (BSZ) watersheds, where a non-degradation treatment level is required.
As with other vegetative water quality controls an Integrated Pest Management (IPM) Plan is required.
Design guidelines for this control can be found in Section 1.6.7.F of the Environmental Criteria Manual.