City of Pittsburgh and PWSA Draft City-Wide Green First Plan

The City-Wide Green First Plan is the City of Pittsburgh and the Pittsburgh Water and Sewer Authority’s plan to manage issues related to stormwater flow.  The Allegheny County region experiences degraded water quality from frequent combined sewer and sanitary sewer overflows into our rivers, due to excessive stormwater overloading our already stressed sewer system.

The plan outlines how Pittsburgh intends to use innovative, cost-effective, and green infrastructure approaches to manage stormwater. Implementing the plan will mitigate local street flooding and sewer backups caused by large rainstorms. The stormwater management practices outlined in the plan will help the City and the region comply with U.S. Environmental Protection Agency (EPA) combined sewer overflow mandates and improve the quality of local waterways.

The plan presents an adaptable solution that will address the root cause of our region’s stormwater challenges by investing in integrated stormwater management infrastructure.  Green infrastructure practices like rain gardens, tree plantings, water detention basins, stream restorations, and pervious pavement mimic natural processes to slow and capture rainwater. This approach reduces the frequency and volume of combined sewer overflows and reduces the likelihood of neighborhood flooding and backups. In addition, green infrastructure provides additional environmental, economic and social benefits that would not be provided with traditional sewer engineering projects.

The draft City-Wide Green First Plan examines the existing stormwater conditions that will guide where green infrastructure will be installed to achieve the most cost-effective and beneficial results to the residents of Pittsburgh. Creating the plan required extensive sewershed and hydrology analysis, community and stakeholder outreach, and consideration of future development projects within the City. The draft plan analyzed 13,700 acres in the City and proposes to manage runoff from 1,835 acres with green infrastructure over the next twenty years.

The draft plan includes concept-level details for six priority sewersheds where green infrastructure would provide significant benefits. The green infrastructure methods to be used in each sewershed were selected based on criteria that considered factors such as cost and community impact. This approach is designed to guide the integration of stormwater management with the City’s capital improvement projects and urban planning process.

The City-Wide Green First Plan is a draft document, and PWSA encourages the public to submit comments.


Please use the following email address to submit your comments:
Comments can also be mailed to:

The Pittsburgh Water and Sewer Authority
Attn: Green Infrastructure Division
1200 Penn Ave, Pittsburgh, PA 15222

Documents can be viewed online, in PDF (portable document format):

Table of Contents:

Acronyms and Abbreviations


Executive Summary




1 Up-Front Planning and Sequencing


2 Establish Target Green Infrastructure Management Level Goals


3 Green Infrastructure Modeling Approach Using GIS and SWMM


4 Flood Hazard Mitigation Analysis


5 Stream Inflow Improvements Analysis


6 Urban Planning and Green Infrastructure Plan


6.1 Green First Approach and Process


6.2 M29 Four Mile Run


6.3 A42 Washington Boulevard and Negley Run


6.4 M16 South Side/South 21st Street


6.5 A41 Heth’s Run


6.6 M19 Soho Run


6.7 O27 Woods Run


6.8 Review: Integrated GI Approach and Meeting the Guiding Principles


7 Cost Estimates Development


8 Triple Bottom Line Analysis


9 City-Wide GI Assessment Summary



Appendix A:

Maps of the 30 Priority Sewersheds With High Yield Drainage Areas

Appendix B:

SWMM LID Sensitivity Analysis

Appendix C:

Model Simulation Results by Sewershed for 4 Scenarios

Appendix D:

Woods Run Stream Inflow Evaluation

Appendix E:

Cost Estimating Spreadsheets

Appendix F:

Urban Planning GI Sewershed Assessment – evolveEA/Arcadis

Sewersheds O-27, A-41, M-19

Appendix G:


Urban Planning GI Sewershed Assessment– Phronesis/Mott MacDonald

Sewersheds M-29, A-42, M-16

Appendix H:

Triple Bottom Line Benefit Calculations