Storm Water Management

MS4 is an acronym for Municipal Separate Storm Sewer System. A separate storm sewer system is any conveyance that transports storm runoff directly to a receiving stream. In addition to the inlets, and pipes we associate with storm sewers, it also includes curbing, swales, ditches, channels, etc. Runoff that enters a separate storm system is not treated for water quality before it enters the waterways.

Storm Water Runoff is defined as rainfall or snow melt flowing across the ground. It flows directly to waterways through ditches, swales, storm sewers, etc., and is not treated. Storm water runoff carries with it, sediment, automotive fluids, fertilizer, trash, and various other pollutants.

A watershed is any land area, large or small, that collects and drains storm water to one location. The City of New Castle contributes to two different watersheds. The Driftwood Watershed is spread out over portions of eight counties and collects the majority of storm water from the city draining to the Big Blue River. The Flatrock-Haw Watershed is spread out over portions of six counties and collects storm water from the extreme eastern and southeastern part of the city draining to the Flatrock River

· Point Source Pollution: Polluted water discharged directly from a single, identifiable pipe or outfall—such as industrial waste streams or Combined Sewer Overflows (CSOs). To manage this, the City of New Castle enforces an industrial Pre-Treatment Program and is actively executing its Long-Term Control Plan (LTCP) to minimize wet-weather sewage overflows into the Big Blue River.

· Non-Point Source Pollution: Contaminants picked up by rain or snowmelt flowing across residential yards, roads, parking lots, farm fields, and construction sites before washing into local rivers. As point-source discharges have become strictly regulated, non-point source runoff has become the primary threat to water quality today. The City’s Storm Water Management Program is designed specifically to capture, control, and prevent this type of runoff pollution.

As a designated Municipal Separate Storm Sewer System (MS4) community, the City of New Castle operates a federally and state-mandated Storm Water Management Program. The program's core objective is to reduce pollutants carried by urban stormwater runoff into local rivers and streams. Community involvement is vital to this mission—residents are encouraged to practice clean water habits at home and report potential pollution violations to city officials.