Stormwater runoff results when rain falls on impervious surfaces like roads, roofs, and parking lots and flows off into our waterways, carrying pollution with it. Fixing stormwater runoff means preventing this flow of pollution. Prince George’s County implemented the solution in the 1990’s with the creation of the first Low Impact Development (LID) technologies. These technologies were designed to capture stormwater runoff much closer to the source, and infiltrate the water back into the ground. In this way, LID addressed the primary problem of impervious surfaces like roads and parking lots – they break the hydrologic cycle by preventing rainfall from soaking into the ground.
LID technologies, often known also as Environmental Site Design (ESD), are the best means currently available to restore missing ecological function in our developed areas by capturing rainfall and returning it back to the ground. LID/ESD technologies, such as green roofs, rain gardens, pervious pavement, street trees, and many others, are designed to capture stormwater flows very close to the source – before the water can run off to storm drains and pollute our waterways. Thus, this technology has the benefit of stopping the stormwater runoff “conveyor belt” that feeds bacteria, toxics, and trash into the Anacostia River.
This is an example of one kind of ESD technology - a rain garden. Instead of the rain water hitting the pavement and quickly flowing directly into the river, picking up toxics, trash, and bacteria, as well as heating up due to the contact of the hot pavement and subsequently raising the tempurate in the River, it falls into the rain garden. The soil, grass, and other plants that form the raingarden slowly filter and soak in the rain water to allow other nearby plants and trees to use this water. The rain garden benefits all plants in its proximity and provides a beautiful garden and habitat for wildlife, all while keeping oil, salt, pesticides, waste, chemicals, and sediment out of our waterways. The rain garden shown is located in the yard of the AWS office and contains all native plants.
AWS and its allies have engaged in focused advocacy to advance the cause of LID/ESD and to get developers, governments, and the public on board in support of widespread implementation. We have had great success so far, but with your help we can do even more. In particular, there are many conservative developers and engineers who have been slow to embrace LID/ESD – even though in many cases it is cheaper than traditional engineering solutions! Small, local solutions are an important part of the stormwater puzzle, and AWS and our partners are working to empower local advocates with training to address stormwater runoff in their communities.
Green Roof at Sidwell Friends School
Anacostia Watershed Society is working towards more green roofs in the District. Our project is funded by the District Department of the Environment. To learn more about green roofs, see what AWS has planned, and apply for a spot on the list to have your our green roof built or for our rebate program look at our program info.