Conventional stormwater management practices haven’t been able to successfully mitigate stormwater or keep up with the effects of increased paving and development in cities around the country. Unresolved, stormwater runoff is by far the biggest problem our rivers face.

LID (Low Impact Development) is the answer to this problem.

LID is based on the idea that stormwater management should not be seen as stormwater disposal. Instead of conveying, managing and treating storm water in large, expensive end-of-pipe facilities, LID handles runoff through small, cost-effective landscape features located at the lot level. This includes not only open space, but also rooftops, streetscapes, parking lots, sidewalks, and medians.

Low Impact Development practices mimic nature's rain cycle by putting the landscape to use in its natural role as a filter, and by recharging groundwater and aquifers. LID's goal is to use design techniques that infiltrate, filter, store, evaporate, and detain stormwater runoff close to its source. LID also uses design approaches to reduce impervious cover on a site. These techniques help avoid large-scale "end-of-pipe" practices that can be costly and present long-term maintenance and liability burdens.

LID practices include greenroofs, rain gardens, rain barrels, cisterns, bioretention, permeable paving, swaling, tree planting, and streambank restoration.

Each year, storm water sweeps 70,000 tons of sediment, trash and toxic pollution from roads, sidewalks and rooftops into the Potomac and Anacostia rivers and their tributaries. This effect is called non-point-source pollution, and it results largely from the paving and development that prevent storm water from soaking naturally into the ground. Storm water also triggers the overflow of the District’s ancient combined sewer system, which dumps 3 billion gallons of untreated sewage into our rivers each year.

The challenge of restoring stream quality in areas that have already been densely developed is daunting. Concrete and steel-based methods of storing runoff and reducing water pollution are not feasible, practical or sustainable in urban areas where density is already at its maximum and improvements to the infrastructure are both costly and extremely inconvenient.

The need for a decentralized approach such as Low Impact Development has never been greater. D.C.'s rivers are unswimmable and unfishable due in large part to storm water runoff and the pollution it carries. D.C. is struggling with the economic reality of funding aging and ever-expanding stormwater infrastructure, like the $1.05 billion Long-Term Control Plan .

LID has numerous benefits and advantages over conventional stormwater management approaches. In short, it is both a more environmentally sound and a more economically sustainable approach to addressing the adverse impacts of urbanization. By managing runoff close to its source though intelligent site design, LID can enhance the local environment, protect public health, and improve community livability—while creating jobs and saving developers and local governments money.