Which law established the regulation of stormwater in the 1970s?

The regulation of stormwater in the 1970s was established by the Clean Water Act. This legislation aimed to restore and maintain the integrity of the nation's waters, addressing pollution discharges and setting regulatory frameworks for managing water quality, including stormwater runoff. The Clean Water Act specifically paved the way for the National Pollutant Discharge Elimination System (NPDES), which includes permits for municipal separate storm sewer systems and industrial stormwater discharges, thus ensuring that stormwater management practices are standardized and effective in controlling pollution. This was a significant step in environmental protection, emphasizing the importance of managing not only point sources of pollution but also the diffuse sources that contribute to the degradation of water bodies through stormwater runoff.