Green Infrastructure News From PWSA

Green Infrastructure News from PWSA

November 2017

Raingarden at the top of Hayson Avenue Hill.

View from the top of the Hayson Avenue hill. This rain garden, located at the top of the hill, captures rain fall and helps to slow the flow of water. The 15 systems work together to reduce flooding throughout the neighborhood.

Red Oak and Hayson Green Infrastructure Tour

The Red Oak and Hayson Green Infrastructure (GI) project, located in the Banksville neighborhood, is the first GI project completed by PWSA to manage stormwater in a residential neighborhood.

A little rain didn’t stop people from attending PWSA’s Red Oak and Hayson Green Infrastructure Tour on November 2 ^nd. After all, the purpose of green infrastructure is to manage stormwater and reduce flooding. It was a great day to see the systems in action.

This quiet residential neighborhood was prone to flooding, and homeowners, particularly those those at the bottom of the hill, frequently experienced basement backups. Since the project was completed no flooding or back-ups have been reported and the project is doing what it is intended.

The tour featured three of the 15 systems built throughout the neighborhood. Starting at the top of the Hayson Avenue hill, the GI systems work together with a series of rain gardens and bioretention systems that filter pollutants, absorb and store water, and slow its flow into the sewer system. The rain gardens include vegetation native to Western PA and plants such as Soft Rush, Switchgrass, Butterfly Milkweed, and Blackeyed Susan, which are often used in rain gardens. Engineered soil, a layer of gravel, and R-tanks make-up the bioretention systems that retain and slowly release water into the ground and eventually to the sewer system.

In addition to reducing flooding, the systems help to improve water quality by removing pollutants from the water. The plants and soils used mimic nature and absorb them into the ground. As a result, they are removed before entering our rivers and waterways.

“Green infrastructure provides the ability to manage stormwater where it falls,” said James J. Stitt, PWSA Sustainability Manager. “We’ll have a greater ability to reduce flooding and meet our regulatory requirements to eliminate combined sewer overflows by keeping stormwater out of the pipes.”

This was the first project PWSA completed in a residential neighborhood. We are pleased to report that it is working to reduce flooding. Collectively, the 15 systems manage 2.23 acres of impervious area, have the capacity to store more than 41,000 gallons of water, and can manage a storm size of .69 inches.

PWSA continues to work with residents to address questions about the plants and vegetation installed in the rain gardens and the systems are monitored to provide data on the amount of stormwater entering and exiting the system.

Green infrastructure is an exciting component of PWSA's Capital Improvement Plan. Three projects are currently under construction and several more are planned for 2018. For more information about PWSA’s Green Infrastructure program, please visit www.pgh2o.com/going-green.

Explore the Woods Run Watershed with us on Sunday, November 12.

Construction Update

Backfilling around the R-Tanks at Centre and Herron Avenue in mid-October. The R-Tanks resemble large milk crates. They are modular pieces that can be combined in various configurations and are used to retain stormwater.

The Pittsburgh Water and Sewer Authority (PWSA) has three green infrastructure projects under construction in three different Pittsburgh neighborhoods. Collectively these projects will reduce combined sewer overflows (CSO) by 2,350,000 gallons per year. These Green First stormwater solutions are the start of many more innovative and cost-effective projects. PWSA has several more scheduled for 2018. As more green infrastructure projects are complete, they will create a network throughout Pittsburgh that will work together to manage stormwater, improve water quality, and improve the quality of life throughout our neighborhoods. Below is a quick update on the projects currently under construction.

Centre Avenue and Herron Avenue, Hill District

This project will direct stormwater into a cascading bioswale with underground water storage. When heavy rains occur, the bioswales located along the road will capture excess water and transfer it through a series of pools and waterfalls to the underground storage unit. Plants and permeable soils will absorb water, while additional stormwater is slowly released into the sewer system. These systems will reduce flooding and is estimated to reduce CSOs by 750,000 gallons of water per year.

Construction of this project is currently 65-percent complete. Contractors have completed installation and backfill of Basin 1 underground stormwater tanks and has completed the sidewalk restoration at the Robinson Street Extension. They are currently working on the final site grading near Basins 1 and 2, installation of concrete landscape edging, and completing the sidewalks and curbing along Centre Avenue.

Additional work includes forming and pouring the concrete weir structure near Basin 1 and beginning installation of permeable brick pavers. Visit PWSA online for more information about the construction of the Centre Avenue and Herron Avenue project .

Hillcrest Street, Garfield

Sitting high on top of a hill in the Garfield neighborhood, this project at Hillcrest Street is converting vacant lots into a stormwater park that will feature rain gardens, bioretention systems, and new trees. The site will capture runoff from the neighborhood during rain events and will be equipped to reduce CSOs by approximately 800,000 gallons of stormwater per year. The project utilizes two vacant lots to slow and retain stormwater runoff. Community input during the design phase informed the project, and it aligns with goals to improve public spaces throughout the neighborhood.

Construction of the Hillcrest project is approximately 50% complete. The contractor has completed installation and backfilling around the underground stormwater tank for System 1, and the new catch basins at Systems 1 and 3 are complete and ready for final tie-in to the sewer system. Remaining work throughout the project includes sidewalk installation, construction of concrete curbs, surface restoration, and water control structures. More information about the Hillcrest project is available on PWSA's website.

Melwood Avenue and Finland Street, Polish Hill

This project in Polish Hill will improve curbing and inlets on a steep slope to reduce the risk of uncontrolled stormwater runoff. The project includes repaving Finland Street from Bigelow Boulevard to Melwood Avenue, installing a new curbline to improve stormwater management and refurbishing the Apollo Street staircase with rain gardens and bioretention systems along the sidewalk. This project is estimated to reduce approximately 800,000 gallons of combined sewer overflows.

This project is approximately 5% complete. During the week of November 13th, the contractor plans to fully mobilize the construction site to work on Systems 1 and 2. This area of the project is the focus for the remainder of 2017 and work on Systems 3, 4, and 5 will begin in 2018. More information about the Melwood and Finland project, is also available on PWSA's website.