Storm Water Management

Storm water runoff rainwater that simply rolls off and away from pavement and buildings rather than seeping into the ground below them has become the focus of many modern water protection efforts. As storm water runoff moves across the top of the earth s surface rather than penetrating the surface immediately upon falling, it acts according to the laws of nature and seeks the lowest point, where it naturally meets other rainwater and quickly forms rivulets and streams. This newly created waterway system collects and concentrates contaminants on its way through developed areas. When the runoff finally enters the groundwater, it is often very polluted. Of course, the more built up the area, the more polluted is the runoff it generates. National and local environmental protection policies are beginning to reflect the public concern about this problem, insisting that storm water runoff be channeled safely throughout the life cycle of a development project.

To prevent water pollution, site designers must now address storm water management practices not only for the finished development but for the construction site as well, from the time the site is first disturbed. As site work begins and progresses and the natural characteristics and irregularities of the site are graded and removed, the volume and velocity of storm water runoff increase. Once the vegetation is gone and the soil disturbed, rainfall and runoff are no longer deflected off the surfaces of the vegetation, and they are unable to infiltrate into the compacted soil. So the water...