Stormwater runoff is a form of non-point source pollution which is given specific attention due to the size of the problem and its damaging affect. Stormwater runoff is the rapid uncontrolled run-off of rainwater seen in heavily urbanized areas where natural forests and fields (pervious surfaces) have been replaced by roads, parking lots, and buildings. These impervious surfaces prevent rainwater from soaking into the ground. Instead, rainwater rushes quickly to streams, creating a large, rapid pulse of water that can scour stream channels so severely that only very large rocks and hard-packed surfaces remain.
Channel scouring resulting from stormwater runoff eliminates habitat for all types of stream animals and contributes greatly to poor water quality. This flush of rainwater can also elevate water temperatures to levels that make streams uninhabitable for some aquatic species such as temperature-sensitive fish species.
Aside from ruining waterways and our enjoyment of them, stormwater runoff impacts people by increasing the likelihood of flash floods and property damage. As with other forms of non-point source pollution, the problem of stormwater runoff increases as development occurs. To prevent this form of pollution innovative land development practices that reduce impervious surfaces, better enforcement of regulations that require capture and treatment of stormwater on site, and protection of stream buffers must be implemented.