Pittsburgh, PA - The Pittsburgh Water and Sewer Authority (PWSA) is installing green infrastructure (GI) at more than six locations around the city. In its 2013 Wet Weather Feasibility Study Report (WWFS), PWSA recommended including a combination of GI and traditional infrastructure, to capture and manage stormwater before it reaches the sewer system. These projects are part of PWSA's City-Wide Green First Plan using site specific environmental practices to manage stormwater and mitigate flooding issues, improve water quality, and increase green space in the places Pittsburghers work, live, and play.
The Allegheny County region experiences degraded water quality from frequent combined sewer overflows into our rivers, due to excessive stormwater overloading our already stressed sewer system. The City-Wide Green First Plan has been adopted by the City of Pittsburgh and the Pittsburgh Water and Sewer Authority as a resilient strategy to manage issues related to stormwater flow in new and innovative ways.
Many Pittsburgh neighborhoods are prone to flooding and the sewer system becomes overburdened during heavy rains. As stormwater flows across paved surfaces and through our combined sewers, it picks up pollutants and carries contaminants to our streams and rivers. Green infrastructure slows down the flow of stormwater and reduces the amount of pollution entering our waterways by incorporating more absorbent, permeable materials and surfaces into roadways, parks, and landscaped areas. This practice directs more stormwater to treatment at ALCOSAN instead of overflowing into our rivers.
“To have three active projects taking place throughout the city is a great step for PWSA’s green infrastructure program,” stated PWSA Interim Executive Director Robert Weimar. “We’re confident that these projects will demonstrate the benefits and effectiveness of green infrastructure to capture and manage stormwater. There is still more work to do. These projects will inform our citywide program and our regulators as to the effectiveness of green infrastructure as more sites are selected.”
Current projects in Pittsburgh’s Garfield neighborhood, the Hill District, and in Polish Hill will reduce localized flooding and stormwater runoff, create safer wet weather conditions, and incorporate additional green spaces into each neighborhood.
Hillcrest Street, Garfield
: Conversion of vacant lots into a stormwater park with rain gardens, bioretention, and tree planting. The site will capture stormwater runoff from the neighborhood during rain events. Curb extensions, sidewalk improvements, and storm inlet replacements will address existing runoff issues and increase the total volume of stormwater managed at this site. Water quality benefits include improved drainage patterns in the neighborhood and an annual reduction estimate of approximately 800,000 gallons of combined sewer overflow from the combined sewer system.
The project utilizes two vacant overgrown lots to slow and detain stormwater runoff from entering the combined sewer system. Community input during the design phase helped inform site selection to align with community planning efforts, to improve public spaces for current residents consistent with the forested character of the neighborhood.
Centre Avenue at Herron Avenue, Hill District
: Stormwater runoff from the surrounding roadways is being directed through curb cuts into a cascading bioswale with underground water storage. When heavy rain events occur, the bioswales located along the roadside will capture excess water and transfer it through a series of pools and waterfalls to the underground storage units. This water then is taken up by the plants or infiltrates back into the ground. Any additional stormwater is slowly released into the nearby storm sewers, avoiding flooding in the street and overloading the sewers. This project will reduce our combined sewer overflows by an estimated 750,000 gallons per year.
Melwood Avenue at Finland Street, Polish Hill
: This project will include construction of improved curbing and additional inlets on a steeply-sloped street to reduce risks of uncontrolled runoff. In addition to repaving of Finland Street from Bigelow Boulevard to Melwood Avenue, a new curbline will be established that improves stormwater management and residents’ property access. Access to city steps along Melwood Avenue at the Apollo Street staircase will be refreshed along with the construction of rain gardens and bioretention plantings along the sidewalk. Two additional bioretention areas will increase the total stormwater capture of the project, with an estimated annual reduction of approximately 800,000 gallons of combined sewer overflow from the system.
The PWSA’s total anticipated investment for design, construction, and monitoring of these three GI projects is $3.3M with an estimated combined sewer overflow reduction of 2,470,000 gallons per year. These projects are supported in part by a grant from ALCOSAN.
These PWSA Green First stormwater solutions are just the start of many more impactful and cost effective GI based projects throughout the City that will manage stormwater and improve our water quality in a manner that also improves the quality of life in our neighborhoods. More details about these projects and the Green First strategy can be found at www.pgh2o.com/going-green.
"Water is one of Pittsburgh's greatest resources, and making these green infrastructure investments will help preserve this asset for generations to come. I want to thank PWSA for its continued commitment to GI principles, which we will build upon in the future," Mayor William Peduto said.
The Pittsburgh Water and Sewer Authority (PWSA) is the largest combined water and sewer authority in Pennsylvania, serving 300,000 consumers throughout the City of Pittsburgh and surrounding areas. Our over 260 employees are city residents and are committed to enhancing Pittsburgh’s quality of life by delivering high quality water.