Carnegie Mellon University
mall storm water retention tank

Pittsburgh Regional Stormwater Management

The Pittsburgh region's frequent rainfall brings an underground, out-of-sight problem into clear view. As little as one-tenth of an inch of rain—an average Pittsburgh rainfall is one-quarter inch—can cause raw sewage to overflow into our rivers and streams. Melting snow can cause the same effect.  Untreated sewage streams into waterways, overflows from manholes or backs up into homeowners' basements.  Nationally, stormwater runoff is our most common cause of water pollution.

During dry weather, the combined storm and sewage collection system, which transports wastewater from thousands of homes to the wastewater treatment plant, operates effectively.

Carnegie Mellon has sustained millions of dollars of damage from stormwater in recent years and have taken some steps to capture or divert rainwater during storm events.  Below are some of the practices we utilize. To learn more about regional stormwater management issues go to the 3 Rivers Wet Weather web site.

CMU Stormwater Management Projects

Jared L. Cohon University Center
The 62,000 sq. ft. addition captures 100% of the rainfall from the roof and drains into three rain gardens.
CUC water garden



Mall Rainwater Collection System
Rain water collection - 280,000 gallon capacity used for chiller make up water.
Building downspouts surrounding the Mall directed to underground tank.
mall storm water retention tank

Gates Hillman Computer Science Complex
Rain water collection - 10,000 gallon tank collects water used for flushing building toilets.
Vegetated swales and tree plantings on hillside, slows water flow.
gates rain water collection tank
4721 Fifth Avenue
A storm water capture was engineered into the perimter of the property during rennovation.
4721 storm water
Collaborative Innovation Center (CIC)
Rain water collection - 6,000 gallon tank, water used for toilets & irrigation.

Purnell Center for the Arts
A 10,000 gallon underground baffled stormwater cistern to slow water flow down.

Green Roofs
Carnegie Mellon also has over a dozen buildings with Green Roofs (living or vegetated roofs).