Storm water is the precipitation (rain or snow) that accumulates in natural (or constructed) storage locations, including storm water conveyance systems, during and immediately following a storm event.

Because storm water is a type of runoff (water from rain or snow that does not infiltrate the soil), it collects on the ground, paved surfaces (parking lots, roads), and building rooftops and eventually flows toward a lower elevation.

In the urban areas, storm water is collected and transported by storm water conveyance systems. These conveyance systems can include underground pipes or open ditches and are separate from the sanitary sewer or wastewater system that carries wastewater to wastewater treatment plants. Storm water is not treated before discharge to a lake or river.

Storm Water Management includes the functions associated with planning, designing, constructing, maintaining, financing, and regulating the facilities (both constructed and natural) that collect, store, control, and/or convey storm water. Under federal regulations, cities have storm water pollution prevention programs that describe a process through which a facility thoroughly evaluates potential non-point pollutant sources at a site and selects and implements appropriate structural and/or nonstructural best management practices (BMPs) designed to prevent or control the discharge of pollutants in storm water runoff.

Click here to learn what you can do to prevent impacts to the river from storm water. Click here to learn more about the NPDES Storm Water Program. Click here to learn what Fargo and Moorhead are doing to meet the new NPDES Phase II storm water regulations.