NTM was involved in this publicly-funded green stormwater infrastructure (GSI) project from the survey review through design, to the entering of data into “Green IT,” Philadelphia Water Department’s (PWD’s) Stormwater Management Practice (SMP) data workbook. NTM designed 12 SMPs and 14 American Disabilities Act (ADA) ramps for this North Central Philadelphia neighborhood. The designs included capture of five green acres (an acre-inch of stormwater). NTM followed the construction by performing regular site visits.
GSI constructed includes bumpouts, tree trenches, and a large rain garden in Danny Boyle Community Park. Fitting GSI into the urban landscape of Philadelphia was challenged by everything from community acceptance to complex underground and overhead utilities. This project successfully provided stormwater management, vegetated surface water quality treatment, and improved community esthetics at a cost that was lower than average. As such, it meets the intent of PWD’s “Triple Bottom Line Approach” of environmental benefits, economic benefits, and social benefits.
NTM designed the GSI in accordance with the PWD Green Stormwater Infrastructure Design Requirements and Guidelines. The guidance was revised during the project, partially based on the observations by NTM that the green inlet and curb cut design standards needed updating. NTM’s SMP calculations included storage volume sizing, inlet flow, quantities take-offs, and hydraulic routing. Curb ramps were designed in accordance with the Philadelphia Streets Department ADA Curb Ramp Design/Construction Approval Submission Requirements and PennDOT District 6-0 ADA Reference Guide.
