The purpose of this handbook is to assist transportation agencies in developing and/or implementing a stormwater management program that satisfies the requirements of the Clean Water Act (CWA). For agencies that already have a functioning stormwater management program, this handbook provides useful tips and transportation specific references to assist program implementation. Throughout this handbook, the terms "stormwater management program" and "stormwater management plan" (SWMP) are used. The term "stormwater management program" refers to the entire program implemented by a transportation agency to comply with their National Pollutant Discharge Elimination System (NPDES) permit(s) for stormwater discharges. The term "SWMP" refers to a specific document that describes the framework for implementation of the stormwater management program for the agency.