Stormwater

Developers, builders, states, municipalities and even homeowners all play important roles managing stormwater runoff to the protect water quality within receiving waterbodies. Effectively managing stormwater runoff can also help communities address the problems such as recharging groundwater within arid climates or help address localize flooding problems during significant rainfall events.

Since the 1990s, the federal Clean Water Act’s (CWA) National Pollutant Discharge Elimination System (NPDES) permitting program has required land developers, builders and even municipalities to obtain federal and state stormwater permits to authorize the discharge of stormwater runoff from their activities. Residential land developers and builders must obtain CWA NPDES Construction General Permits (CGP) prior to conducting any site grading or construction activities that disturb soils of an area greater than one acre, or less than one acre but are located within a larger area of development (i.e., a single building lot within a larger residential subdivision). NAHB has several resources available that explain how the CWA’s NPDES CGP works, including resources of small builders working on individual building lots within a larger residential subdivision.

CWA’s NPDES also requires municipalities with municipal sanitary sewer systems (MS4) to obtain NPDES stormwater permits and establish stormwater management programs (SWMPs) that require developers and builders to comply with local stormwater ordinances, including the management of post-construction stormwater runoff from already built residential subdivisions. NAHB has developed a number of resources explaining municipal post-construction stormwater requirements, including comparing different types of post-construction stormwater requirements imposed upon developers and builders by municipalities.

Increasingly, municipalities, developers, and builders are exploring new techniques to manage stormwater runoff such as green infrastructure which employs natural systems (e.g., soils and plants) to mimic natural systems to filter and absorb stormwater runoff at its source rather than traditional stormwater infrastructure that captures, stores, transports and treats stormwater runoff within a municipalities’ MS4 system. NAHB has a number of resources explaining green infrastructure concepts and some of the administrative barriers to their wider application.