Stormwater Runoff

Stormwater runoff is the leading cause of nutrient and sediment pollution in Baltimore’s waterways.

In our urban region, pavement and other impervious surfaces cover more than 45% of Baltimore’s landscape, preventing rain from soaking into the ground.

Stormwater Runoff

What is stormwater runoff pollution?

Every time it rains, trash, bacteria, heavy metals, and other pollutants are washed from city streets and roofs into local streams and the harbor.

Impervious surfaces – including roofs, streets, and sidewalks – keep rain from soaking into the ground and being treated by plants and trees. Instead, this untreated, polluted stormwater washes straight into nearby streams. 

Stormwater runoff is one of the leading causes of nutrient and sediment pollution in Baltimore and the Chesapeake Bay. With increased rainfall from climate change, runoff is predicted to increase in the coming years.

Stormwater runoff pollution causes:

Download our full stormwater infrastructure report

Stormwater runoff is the leading cause of nutrient and sediment pollution to Baltimore’s waterways.

Read our comprehensive report on the challenges & solutions for Baltimore’s current state of stormwater infrastructure.

Stormwater Runoff

Green stormwater infrastructure

Green stormwater infrastructure is a cost-effective way to combat stormwater runoff and pollution. Green roofs, rain gardens, and pervious pavement are all examples of green stormwater infrastructure. 

Green stormwater infrastructure


Rain Gardens

Rain gardens can be scaled to fit into a variety of settings and intercept stormwater next to parking lots, buildings, or between a sidewalk and street, to capture stormwater before it enters the sewer.


Green Roofs

Green roofs are plant beds that reduce runoff from the tops of buildings. In addition to being a rainwater buffer, they purify the air and can help regulate ambient and indoor temperature, which provides energy cost savings.


Rain Barrels & Cisterns


Cisterns and rain barrels come in a variety of shapes and sizes and connect to downspouts to collect rainwater for later use, reducing reliance on drinking water.

Trees & Tree pits


Trees and expanded tree pits along streets are another effective GSI practice, reducing pavement and allowing soils and vegetation to absorb runoff.

Pervious Pavement


Replacing pavement with pervious or porous paver technology allows water to soak into the ground while still providing a hard surface for pedestrian, bike or auto use.

How to help

How we fight stormwater runoff pollution

From organizing community tree plantings to installing rain gardens, our work directly helps to reduce stormwater pollution. Our programs focus on community-based restoration, advocacy, and education to achieve clean water in Baltimore’s watersheds.

One Water Partnership helps religious groups identify and implement stormwater reduction practices. Our Eco-literacy programs provide ways for all ages to learn how they can help tackle pollution locally.

Our mission is to restore the quality of Baltimore’s rivers, streams, and harbor to foster a healthy environment, a strong economy, and thriving communities.

Here are the best ways to get involved

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