The indigenous soil and forests of many regions accumulate, sieve, and gradually release fresh, clean water to streams, wetlands, and estuaries. The varieties of life in marine and fresh water, as well as on land, require clean water to thrive.

As human populations intrude and alter natural settings, native forests and soils are replaced with roads, rooftops and other hard surfaces. When it rains or snows, more water flows from these surfaces than undisturbed areas, carrying oil, fertilizers, pesticides, sediment and other pollutants downstream. In fact, much of the pollution in streams, wetlands and rivers now comes from storm-water (water flowing More >