Helping Nature Heal Itself

Parking Lots and Rain Gardens

See how rain gardens are making a huge difference in fighting water pollution, cleaning air and providing animal habit in urban environments.


The work that we’re doing in cities is very important. Our cities are expanding, having an impact on our ecosystems and on our local waterways.

In Washington, DC, we are very focused on stormwater runoff. It is the largest growing source of pollution to the Chesapeake Bay watershed. When it rains, rain hits concrete, it picks up chemicals, pollution coming off of cars, off of yards and pet waste, and if flows directly into our urban waterways. Here in DC, we see urban stormwater flowing into the Anacostia River, the Potomac River, and ultimately, the Chesapeake Bay.


The Anacostia River is the poster child for stormwater pollution. We have about a million people that live in our watershed. We’ve hardened about 25% of the actual surface area that all used to be forested. So it creates a flash flood of rainfall runoff because what used to get soaked into the ground now just rushes to the closest drain.

KETTERING: What we’re doing in DC is building rain gardens to help deal with this problem. Green space helps to clean the air as well as retaining stormwater and providing habitat for wildlife and green spaces that people can enjoy.

The Nature Conservancy partnered with the Anacostia Watershed Society on this very innovative project here at the First United Methodist Church of Hyattsville. This was a 2 to 3 acre parking lot of completely impervious surface.


It was a lot of asphalt. We had problems with flooding. A lot of times the sewer system would back up because there was so much water coming down, not only collecting from our property but also further upstream.

KETTERING: What we did is we came in, strategically put in bioretention, rain gardens, trees to capture stormwater run off as it flows.

FOSTER: The trees and the plants - we put about 4,000 plants in the ground here so far - will all take up that water. We’re going to basically take about 2 million gallons a year out of the stormwater system. Water will sheet flow off the parking lot into the pervious pavement. When it overfills that it will flow into the bioswale.

SHRADER: Before we put these rain gardens in, we were contributing a lot of runoff. It was a lot of pollution from the cars and the oil that was going down into the watershed. And we wanted to do our part to help change that.

KETTERING: It’s amazing to see how nature can heal itself with a little bit of help. The Anacostia River got degraded, but from projects like this we are able to come together and be part of the solution. Now, I can go down on the Anacostia River and I can go kayaking and enjoy it.

FOSTER: The river should be clean. It should be a destination. It shouldn’t be a “forgotten” river, which is what it’s been. It should be a place that inspires people, as well as adding economic value. We’re seeing huge development happening along the Anacostia and it’s really based on a clean river.

Learn more about our urban conservation efforts, as we use the power of nature to make cities more resilient and livable places.


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