Welcome to Stormwater Basics

Stormwater is a component of the overall water cycle: precipitation falls to earth, some of which is absorbed into the ground and some of which makes its way into streams and rivers, and eventually to oceans. In a natural environment, stormwater will soak into soils and soft surfaces, and some also runs into area streams. However, in our urban setting, a greater amount of stormwater runs off rooftops, sidewalks, parking lots, asphalt and other such impervious surfaces, and then goes into the storm drain system, and eventually into area waterways.

Stormwater is rainwater, snowmelt, or even water from a garden hose or car wash that runs off of a surface (like driveways, parking lots, or rooftops) and goes into a gutter, ditch, or roadside drain, and ultimately into the storm drain system. In our area, stormwater does not go to a treatment plant, so any pollutants carried in the stormwater are discharged into waterways and the environment.

A storm drain system is a network of constructed inlets, underground pipes, drainage channels, and other structures that carry and temporarily hold stormwater to be discharged into streams and waterways. A storm drain system’s main role is flood control.

Please see the links to the left for more information on how SEMSWA works its Residents to protect our stormwater quality.