Pittsburgh Green Infrastructure Citywide Evaluation

Green stormwater infrastructure works best as a system that integrates water and ecological systems into community open spaces. evolveEA was part of a professional team to help define “water first” planning that integrates environmental performance, economic opportunity, and culture and community. We worked with Pittsburgh Water & Sewer Authority (PWSA) and Arcadis to identify Pittsburgh green infrastructure opportunities through a city-wide evaluation of combined sewer overflow priority sheds. The project was established to help PWSA meet their requirements for the EPA’s Consent Decree to keep raw sewage and contaminated stormwater out of natural fresh water resources. This project was also intended to set up a replicable process that is deployed in other city sewersheds.

Designing an integrated watershed network 

Our process created a watershed network for Pittsburgh green infrastructure to capture, convey, and store water in the public right of way, open space, or parks. In most cases, a “water first” solution also creates opportunities for more ecologically robust greenways and places for trails, parklets, and other amenities for communities.  Our scope included a large scale system schematic, identification of key components in the system, priority projects, and opportunities for public-private partnerships. The green infrastructure methods to be used in each sewershed were selected based on criteria that considered factors such as cost and community impact and sewershed performance was modeled to find the net decrease of overflow within the city-wide system.

Implementing Green First

Our report was part of PWSA’s Green First Plan (2016), which features conceptual designs for six priority sewersheds and identifies where green infrastructure would provide significant benefits. The team also helped PWSA evaluate the administrative processes and policies that can support a sewershed approach to green infrastructure. Our work has helped inform the business case for green infrastructure, policies to support green infrastructure, and administrative protocol for agency alignment and public outreach.