PWSA - Pittsburgh Water and Sewer Authority
09/04/2024 | Press release | Distributed by Public on 09/04/2024 07:02
PWSA Wraps Dragoon Way and Haverhill Street Stormwater Projects
Neighborhood-based stormwater systems will manage rain where it falls
Pittsburgh, PA - The Pittsburgh Water and Sewer Authority (PWSA) has completed two new stormwater projects. One is located on Dragoon Way in the Stanton Heights neighborhood and another on Haverhill Street in the Homewood South/East Hill neighborhood.
These two projects, a combined investment of $3 million, help to reduce overland flooding by managing stormwater through green engineered solutions that are integrated into the neighborhood. On Dragoon Way, stormwater retention tanks have been installed underneath streets to hold water during heavy rains and slowly release it into the sewer system. On Haverhill Street, hillside stabilization and improved curbs and roads will help channel and manage stormwater.
We are proud to approach the issue of stormwater in Pittsburgh with innovative green and gray solutions," said PWSA Chief of Engineering Rachael Beam. "We hope projects like these can be examples of how we can use new technology and approaches to solve long-standing problems," she said.
A New Vision for Stormwater Management
During rain events, combined sewers can become overwhelmed and overflow into local waterways. Stormwater management practices look to reduce the volume of water in pipes during peak rain events.
Pittsburgh's sewer system, largely built in the early 1900s, was constructed according to the standards of the day. That meant that many of the sewer pipes were built to collect both sewage flows from homes and businesses, but also stormwater from downspouts and storm drains. These are called combined sewers and account for approximately 75% of the sewers in Pittsburgh.
While these pipes function as designed during dry weather, they can pose difficulties during heavy rains, overwhelming the sewers and causing combined sewer overflows, or CSOs, which can negatively impact water quality in waterways around Pittsburgh and cause problems on individual properties like overland flooding and basement backups. Development of more buildings, roads, and less green space than when our infrastructure was originally built puts further stress on our sewer system.
To address some of the negative impacts of combined sewers and an increased demand on our sewer system, we are building a new wave of stormwater infrastructure that captures the rain where it falls, soaks into the ground, and is slowly released back into the sewer system. These projects use a combination of green and gray infrastructure that on the surface mimic nature using vegetation, engineered soils, and open channels that retain water. Underneath are storage systems that hold water back before slowly releasing it through our network of sewer pipes. The new projects are cost-effective and help to reduce basement backups, sewer overflows, and improve water quality.
Dragoon Way Stormwater Project
A stormwater retention tank being installed as part of the Dragoon Way Stormwater Project
This area of Stanton Heights has historically experienced flooding on public and private property due to inadequate stormwater infrastructure. It is within the A-41/Heth's Run sewershed and experienced significant combined sewer overflows into the Allegheny River. To address this, our engineering team designed a stormwater improvement project with these goals in mind:
- Reduce overland flooding in the area
- Achieve downstream flood reduction and reduce peak water flows within the sewers
- Install approximately 650-feet of new dedicated storm sewer.
- Install two subsurface stormwater detention systems under Dragoon Way and Adelphia Street (see above right image).
- Improve roadway drainage systems via new pavement and curbs
- Rehabilitate the stormwater sewer outfall, located below Adelphia Street
This project began in Spring 2024 and was completed in August 2024. The stormwater system improvements will manage stormwater on 2.65 acres of land, of which, a little over half is impervious surface, or hard surfaces that do not absorb stormwater. Although residents will not see the underground stormwater system, they can have every confidence that the storage system is working for them during heavy rains. This was a $1.7 million investment in the area.
Haverhill Stormwater Improvements Project
This project was identified after groundwater seep caused a landslide on Haverhill Street in the Homewood South/East Hills neighborhood in 2018. Since 2014, this was an area of focus for stormwater management solutions, with UpstreamPGH leading the charge with the Rosedale Runoff Reduction Project, completed in 2016. The 2018 landslide inundated the stormwater systems with sediment and made clear that a more robust solution was needed.
PWSA's project design team identified the following solutions:
- Stabilize the hillside above Haverhill to manage seepage with an engineered slope and trees.
- Improve roadway and curbs to allow stormwater to flow properly away from Haverhill hillside.
This project began in spring 2024 and was completed in late summer. This was a $1.3 million investment to stabilize and improve drainage along the hillside above Haverhill Street. The project was partially funded with a $220,000 grant from the Allegheny County Conservation District and a cost-share with the City of Pittsburgh to stabilize City-owned vacant property and repave Haverhill Street.
Before the hillside stabilization on Haverhill Street
After hillside stabilization
What's Next?
PWSA continues to determine the best locations around our service area to utilize green stormwater solutions, with over $50 million invested since 2019. In addition to capital investments in our system, our Operations team is at work every day, televising our sewers to keep them in good condition, cleaning our debris and blockages, and replacing aging storm drains to keep stormwater flowing efficiently.
For more information about our stormwater program, projects and how you can help manage stormwater on your own property, please visit www.pgh2o.com/stormwater.