The change of natural pervious surfaces into impervious surfaces due to urbanization, construction, and development causes excess stormwater runoff and results in cities experiencing localized flooding events. The installation of green stormwater infrastructure (GI) is one way of reducing flooding events and preventing downstream erosion and damage. In this study, computer rainfall-runoff simulations were performed to analyze the effect of city regulations on GI practices. A mixed-use development site was used as a model site to perform the analysis. 

The study was conducted assuming the same design would be constructed in six cities in the southeastern United States. These cities were selected to represent small to medium-size cities with different design storm intensities. The cities’ stormwater ordinances were reviewed, and some of the requirements were re-phrased to stress GI implementations. From the ordinance analysis, four sample regulations were developed with various levels of GI requirements. Using the HydroCAD stormwater modeling tool, hydrologic simulations were performed for the six cities based on these requirements. A total of 24 simulations were performed. Based on the hydrologic simulations results, by making some modifications to their ordinances, cities can reduce the amount of runoff and required storage size.
Even though GI has been commonly implemented in large cities, small and medium-sized cities can also prevent excess stormwater by incorporating GI in their ordinances for new developments and site retrofits. Details of the analysis and results will be presented.

Effect of City Regulations on the Implementation of Green Stormwater Infrastructure

Created in 1999, the Environmental & Water Resources Institute (EWRI) is the recognized leader within ASCE for the integration of technical expertise and public policy in the planning, design, construction, and operation of environmentally sound and sustainable infrastructure impacting air, land and water resources.

[Paper Proceedings](https://doi.org/10.1061/9780784483466)

Conference DOI: https://doi.org/10.26226/m.6329c39b68fb0e00131f77d2