Implement water quality protection regulations using zoning requirements or a design overlay including the following design criteria: z Use site design practices for conserving natural features, reducing impervious cover, and using natural drainage systems, and z Treat the Water Quality Protection Volume (WQv) by reducing total suspended solids from the development site for runoff resulting from rainfalls of up to 1.5 inches (85th percentile storm). Planning for the type and location of green stormwater infrastructure needs to consider the pollutant(s) of concern, available right-of-way or land, existing soil conditions and infiltration rates, and other specific aesthetic goals of the proposed improvements. The following is a table of GSI systems to consider for treating water quality: GSI System Definition GSI Design Types Suitability Constructed Wetland Stormwater wetlands serve larger drainage areas where the water quality volume is treated by wetlands species and stored for a short to long period of time. Different wetland habitats can be utilized for these systems including wet meadows, emergent species dominated, and forested wetlands These systems are most suitable for park areas, floodplains, and adjacent to lacustrine areas (relating to or associated with lakes)
Wet (pond) Basin
These systems are designed to retain runoff in ponds with standing water for long term water treatment. They require a source of water to keep a permanent pool and are suited for larger drainage areas. These systems are typically used for flood control, but the extended detention time can have positive effects on water quality by capturing sediment, trash, and debris.
Wet ponds, stormwater ponds, and retention ponds
These systems are most suitable for high density neighborhoods, mix use, and big box commercial areas These systems are most suitable for big box commercial areas and often do not provide habitat and recreation opportunities
Extended (dry) Detention Basin
The City of Fort Worth requires these systems for flood control mitigation and in some cases streambank protection for certain development
Constructed Wetland
Wet (pond) Basin
Extended (dry) Detention Basin
Bridgeland Creek Parkway. Souce: hrgreen.com
Wet basin in north Austin, Texas.
Detention Basin at Battle Bend in Austin, Texas.
GREEN STORMWATER INFRASTRUCTURE
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