Green Stormwater Projects

Centre and Herron Green Stormwater project located in the Upper Hill District

We can reduce flooding, decrease water pollution, and build new stormwater solutions to change Pittsburgh's infrastructure for the better.



Pittsburgh’s first sewer lines were established in the 1840s in what is now present-day Shadyside and Oakland. These lines sent water directly to the Monongahela River. By 1908, nearly 400 miles of underground sewer lines were in place, establishing the start of our 1,200-mile combined sewer system.

Historic Photo, PGH2O

Today, Pittsburgh looks a lot different.

There are more buildings, more roads, less green space, and greater demand placed on our infrastructure. While many things have changed, the way we treat wastewater and stormwater largely remains the same.

What does all this mean?

Rendering of a completed stream restoration near Nobles Lane and Ansonia Place

Our combined sewer system sends wastewater and stormwater through one pipe to ALCOSAN, the regional wastewater treatment plant located along the Ohio River. Once water is treated, it is released into the river for downstream communities to use as drinking water.


Our sewer system is overwhelmed by the increasing intensity and frequency of rain. And with so much pavement and hard surfaces throughout the city, all this rain has no where to go.


Sewage frequently overflows into rivers, floods our streets, and overflows into basements throughout Pittsburgh. This method of sending wastewater and stormwater through one pipe is no longer acceptable.

How are we addressing this problem?

A bioretention area at the Hillcrest Stormwater Project in Pittsburgh's Garfield neighborhood.

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.


They 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. As we build up our network of stormwater infrastructure throughout Pittsburgh, they will become more effective at addressing some of our most crucial stormwater challenges.

Understanding Stormwater Issues



As heavier and more intense rains overwhelm our sewer system, stormwater management is a growing concern throughout Pittsburgh. Heavy rains cause sewage to overflow into rivers and streams, flood our streets, and backup into basements. To solve the problem of too much stormwater, we are managing it more deliberately across Pittsburgh. Read more about our stormwater program and the plans we are implementing to effectively manage it.

Help Manage Stormwater

Help Manage Stormwater

The way we think about stormwater is changing. There was a time when residents felt they had no choice but to live with a flooded basement or sewage backing up into their home. But that’s not the case any longer. 

  • It’s not healthy! State and Federal regulators require us to address sewage overflows and basement backups through improved stormwater infrastructure. 
  • There’s more rain. With heavier, intense and more frequent rainstorms, the number of flooding and backup events is increasing. We need to manage stormwater differently.
  • It’s expensive. Constantly cleaning your home after a flood adds up. And with increasing property values, residents want to protect their homes and investment. 

Continue reading for more information about how you can help manage stormwater.