The document summarizes the history and evolution of stormwater management regulations in the United States from the 1940s to present. It discusses the key laws passed including the Clean Water Act and its amendments. It describes the development of NPDES permitting programs for municipal separate storm sewer systems and the establishment of effluent limitation guidelines and best management practices for stormwater. It also discusses the concept of "maximum extent practicable" in regulating stormwater discharges.