Green Stormwater Infrastructure (GSI) has become a popular method in urban stormwater management. We examined how spatial distribution of GSI affected rainfall-runoff relationships in a recently developed neighborhood in Gresham, Oregon, USA for the 2017-2018 water year. Runoff ratio, peak discharge, and flashiness were compared under four precipitation scenarios (of differing intensity and duration) and different spatial arrangements of GSI. Distributed GSI reduced runoff ratio (10 - 20%), peak discharge (26 - 68%), and flashiness index (56 - 70%). Distributed GSI outperformed centralized structures for all metrics, reducing runoff ratio (22 - 32%), peak discharge 67 to 69%, and flashiness index (32 - 62%). This research serves as a basis for urban stormwater managers to understand potential impact of GSI on reducing runoff and downstream flooding in small urban watersheds with frequent rain.
Fahy, Benjamin and Chang, Heejun
"Effects of Stormwater Green Infrastructure on Watershed Outflow: Does Spatial Distribution Matter?,"
International Journal of Geospatial and Environmental Research: Vol. 6
, Article 5.
Available at: https://dc.uwm.edu/ijger/vol6/iss1/5