Use of Green Roofs for Ultra-urban Stream Restoration in the Georgia Piedmont (usa)

Stormwater management has traditionally focused on the use of conveyances to quickly move stormwater runoff from urban centers into nearby rivers, streams, and lakes. The increased flow caused by impervious surface cover (ISC) leads to runoff rates that are amplified by kinematic processes as they travel through the municipality’s stormwater system. Elevated runoff volumes and rates lead to high pollutant transfer and altered hydrology that adversely affects urban stream ecosystems, water quality, and human health. Vegetated roof cover provides a means for reducing stormwater runoff, while providing additional aesthetic and environmental benefits. We tested vegetated roof plots at the Boyd Graduate Studies Building on the campus of the University of Georgia from October 2003 to the present for their effectiveness in reducing stormwater flows. Performance results were found for a large range of storm events. Spatial analysis was performed in an urban watershed (Tanyard Branch watershed in Athens, GA) to evaluate widespread green roof implementation. Resulting management scenarios are discussed.