Green Stormwater Infrastructure

Buildings, roads, parking lots and other impervious surfaces shed rain more rapidly than areas covered by vegetation. Because of this, urban land development tends to increase the intensity of storm water flows and the amount of pollution that reaches our water resources. One way to counter the effects of urban development is by installing green stormwater infrastructure (GSI). GSI includes management practices such as rainwater cisterns, rain gardens, bioretention basins and pervious pavers. These features mimic natural filtering processes and treat stormwater runoff before it flows into local streams and lakes. In addition to protecting water quality, GSI reduces flooding, enhances green space and can provide beneficial habitat for wildlife.

With financial assistance from the EPA and the Texas Commission on Environmental Quality (TCEQ), NTMWD created a treatment train of features to demonstrate GSI techniques and encourage stewardship of water resources. Located in the parking lot of the Wylie campus, the treatment train includes a series of features that work in tandem to clean stormwater before it is released into an adjacent stream. Drought tolerant buffalo grass was also planted around the installation.

Bioretention Basin - Excess stormwater from the rain garden and parking lot flows into the bioretention basin where engineered soils and native and adapted plants continue to filter pollutants from the water. The engineered soil provides favorable growing conditions for vegetation and promotes filtration at a quicker rate than native North Texas soils. Native and adaptive plants uptake nutrients such as phosphorus and nitrogen through expansive root systems. The NTMWD bioretention basin is designed to treat runoff from rain events up to 1.5 inches received within a 2-hour period, and it was built with a drainpipe that carries filtered stormwater underground to a nearby stream.