Library Square Green Infrastructure Retrofit

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What is polluted runoff?

Parts of the Chesapeake Bay watershed contain a high percentage of impervious cover – paved or other hard surfaces such as roofs and roadways that prevent rain water from being absorbed into the ground.  Instead, water runs along these surfaces, collecting trash and substances such as motor oil, lawn fertilizers, and pesticides.  This polluted stormwater flows into streams and rivers, where it threatens aquatic ecosystems and public health.  

Effective stormwater management, on the other hand, creates safe paths for polluted runoff to be captured and filtered through the ground before it reaches waterways.  This helps keep the environment clean and our communities healthy!

A construction worker builds a rain garden. Credit: Blue Water Baltimore.
A view of the construction site. Credit: Blue Water Baltimore.


Project location: Baltimore, MD

Problem:  Library Square is a one-acre parcel of green space located behind a public library in an otherwise densely developed and impervious area.  High volumes of polluted stormwater from surrounding streets drain through the site via to the buried Harris Creek, which flows into Inner Harbor and then the Chesapeake Bay.  The stormwater conveyance system was overwhelmed during heavy rain events, causing neighborhood streets to flood.  While Library Square was a treasured community open space, it was not living up to its stormwater management potential.

Solution:  A collaboration between Blue Water Baltimore, Friends of Library Square, and other partners enabled Library Square to be retrofitted with green infrastructure.  Project elements included a plaza made from permeable pavers, which allows water to filter into the ground, as well as three rain gardens with native plantings that absorb excess runoff and provide habitat for pollinators and birds.  The space was also enhanced with new public seating areas.  The project has not only improved Library Square’s ability to treat stormwater runoff; it has also made it an even more attractive place for area residents to relax and recreate.

Funding sources: Chesapeake Bay Trust; MD Department of Natural Resources

Partners: Banner Neighborhoods; Biohabitats Inc.; Blue Water Baltimore; Friends of Library Square

More information

Contact information:

Jessie Hillman | Blue Water Baltimore |

Key project facts

Project Type:
$250,000 - $499,999
Story Focus:
Environmental Justice, Environmental Benefits, Community Engagement, Business Partnerships
Stormwater Utility Funds:
Problem Addressed:
Aesthetics, Erosion, Failing Infrastructure, Flooding / Drainage, Health Hazard, Runoff Pollution
Year Installed:
State Legislative District:
Congressional District:
MD 7th