subject: Runaway Runoff: Storm Water Bmp [print this page] The impact of human activity on waterways is undeniable. Large expanses of pavement, roofs and retaining walls shed storm water ever faster into increasingly constricted channels, causing flash flooding, fish kills, erosion and rapid distribution of pollutants. The condition of receiving waters is immediately and obviously degraded every time it rains. Potential pollutants of concern may come from sewage treatment plants, drainage from gas stations and parking lots, soil laid bare by construction, and factories producing industrial waste.
Prevention of storm water runoff is currently being addressed with local, state and national guidance documents outlining best management practices (BMP) for construction, industry, agricultural and residential applications. Municipal planning and building codes that require use of low-impact development elements such as permeable paving surfaces and green roofs have made progress in runoff abatement.
Water holding areas of different sizes slow the on-rush of sudden storms. For example, rain gardens are popping up in suburban lots and parks, and lakes or wetland habitat are being developed downstream from urban watersheds to give water a place to slow down and rest before it is carried to rivers and out to sea. Rain barrels and cisterns can collect rain water for future use on-site before it even gets to a stream. Aquatic plants and microorganisms growing in these containment areas contribute to pollution removal.
Application of specific storm water management techniques will vary from place to place. Anyone with responsibility for planning, building or use of land should be familiar with local storm water management requirements. Even though some places currently encourage storm water BMP as guidelines, the trend is to enforce these practices as laws, complete with fines and other penalties.
Studies on the expected costs and environmental benefits of various storm water management techniques are in progress. As the data continues to accumulate, storm water BMP will continue to be updated and refined.
