RE-EVALUATING STORMWATER

The report presents a model for urban watershed restoration in the Pittsburgh region, specifically focusing on the 6.5 square mile Nine Mile Run watershed. It argues for 'restorative redevelopment,' which embeds the removal of stormwater from sewer systems into the incremental process of urban renewal. By using 'green infrastructure'—such as bioretention areas, porous pavements, and cisterns—the model aims to reduce combined sewer overflows (CSOs) and sanitary sewer overflows (SSOs) while providing community benefits like beautification and recreational amenities. The report details four sample designs (Hunter Park, Edgewood Crossroads, Sterrett School, and Regent Square Gateway) that meet specific hydrologic and budget criteria, and recommends the establishment of a permanent coordinating body to manage the watershed across municipal boundaries.

• The 'restorative redevelopment' model aims to solve sewer overflows and stormwater runoff at the source by absorbing costs into the incremental redevelopment of urban areas, thereby reducing the need for costly single-purpose infrastructure like larger pipes and expanded treatment plants.
• The report identifies several technical strategies for removing stormwater from sewers and restoring natural processes, including capturing roof runoff in cisterns, using porous pavements, rehabilitating soils to increase infiltration, and 'daylighting' historic streams by excavating culverts.
• Sample designs for the Nine Mile Run watershed were required to infiltrate or detain runoff from a '2-year, 24-hour' storm on-site, within a construction budget of $2 per gallon of hydraulic capacity.
• The Hunter Park design demonstrates how a neglected urban park can be used as a catalyst for restoration, utilizing a woodland bioretention area, constructed wetlands, and the daylighting of a culverted stream to treat runoff from the park and adjacent residential blocks.
• The Edgewood Crossroads design highlights the economic benefit of small-scale residential retrofits; for example, a $1,000 grant per home for infiltration beds could be paid off in 8 years through savings at the sewage treatment plant.
• The Sterrett School design illustrates the educational potential of watershed restoration, using cisterns to divert roof runoff from combined sewers for irrigation and a student-designed 'Art Creek' mosaic to teach the hydrologic cycle.
• The Regent Square Gateway design focuses on the confluence of the urban watershed and Frick Park, using terraced underdrained basins and filter embankments to treat runoff from Braddock Avenue and the retail parking lot.
• The report argues that a permanent coordinating body is necessary to manage the watershed's infrastructure and ecosystems because these systems transcend municipal boundaries.
• The report advocates for 'green infrastructure,' which expands the definition of stormwater infrastructure to include the biological and physical capacities of soil and vegetation to absorb water and filter pollutants.
• The policy team recommends a comprehensive action plan including the restoration of the hydrologic regime through monitoring and modeling, the improvement of stream channels and floodplains, and the conservation of urban watershed habitats.

APA

Ferguson, B., Pinkham, R., & Collins, T. (1999). RE-EVALUATING STORMWATER. RMI. https://rmi.org/app/uploads/2017/05/RMI_Document_Repository_Public-Reprts_W99-22_ReevalStormwater.pdf

Chicago

Ferguson, Bruce, Richard Pinkham, and Timothy Collins. RE-EVALUATING STORMWATER. RMI, 1999. https://rmi.org/app/uploads/2017/05/RMI_Document_Repository_Public-Reprts_W99-22_ReevalStormwater.pdf.

Wikipedia

{{cite report |last1=Ferguson |first1=Bruce |last2=Pinkham |first2=Richard |last3=Collins |first3=Timothy |title=RE-EVALUATING STORMWATER |publisher=RMI |date=August 1999 |url=https://rmi.org/app/uploads/2017/05/RMI_Document_Repository_Public-Reprts_W99-22_ReevalStormwater.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{ferguson1999reevaluating, author = {Ferguson, Bruce and Pinkham, Richard and Collins, Timothy}, title = {{RE-EVALUATING STORMWATER}}, institution = {RMI}, year = {1999}, month = aug, url = {https://rmi.org/app/uploads/2017/05/RMI_Document_Repository_Public-Reprts_W99-22_ReevalStormwater.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }