Green infrastructure enlists processes found in nature to manage stormwater and reduce stormwater runoff. Capturing and removing runoff from small storms helps improve water quality, as traditional runoff contains pollutants which affect receiving bodies of water. GI practices are proven effective in meeting stormwater management objectives. However, the tools available for implementing an optimized design often require specialized expertise or additional tools. Authors J. Ross Ellis; Don Guy Biessan; Frances C. O’Donnell, Ph.D.; Jose G. Vasconcelos, Ph.D., M.ASCE; and Benjamin F. Bowers, Ph.D., P.E., M.ASCE, sought to create a simple methodology combining an optimized selection of GI practices and an optimized detention basin, while providing geometric characteristics of both.

Their study published in the Journal of Hydrologic Engineering, “Developing a Practical Tool for Integrating Green Infrastructure into Cost-Effective Stormwater Management Plans”, incorporates two case studies using their testing method (a novice and an experienced designer).  Both tests were successful and show how this tool can help bridge the knowledge gap in green infrastructure by affording easy trials of alternative designs. Learn more about their research in the abstract below, or by reading the full paper in the ASCE Library,        

Green infrastructure (GI) practices are an effective means for improving the sustainability of stormwater management. Optimized combinations of GI practices with other management practices, such as detention basins, can maximize performance and cost effectiveness, and simple methods for identifying these combinations will promote more widespread use of GI. We created a spreadsheet-based decision-support tool to help designers to develop cost-effective stormwater management plans that integrate GI practices with detention basins. The hydrologic impact on detention storage of using GI practices is modeled with rainfall-runoff simulations. An optimization model for a detention basin was developed to be used in conjunction with the spreadsheet tool. We applied the tool to a representative case study site for which the actual design and cost estimates of stormwater infrastructure were known. The tool provided realistic results and the case study revealed that successive applications of the tool could easily provide the user with a site design that improved cost-effectiveness. A sensitivity analysis illustrated the critical trade-off relationship between GI costs and detention basin costs.

Read the full paper in the ASCE Library: