The Southern California Coastal Water Research Project (SCCWRP) is a public R&D agency that develops and applies next-generation science to improve management of aquatic systems in Southern California and beyond. Since its founding in 1969, SCCWRP has been developing strategies, tools and technologies that the region’s water-quality management community relies on to more effectively protect and enhance the ecological health of Southern California’s coastal ocean and watersheds. SCCWRP’s reputation is built on conducting scientific research and translating it into actionable guidance and recommendations that inform management decision-making and policy development. SCCWRP science has served as the basis for discharge permits and watershed basin plans, runoff requirements for new development and redevelopment, biological objectives for aquatic life, sediment quality criteria, and microbial contamination standards for beach ocean water. SCCWRP also plays a key role in developing and facilitating long-term regional monitoring programs, promoting stewardship and sharing of environmental data, and informing regional planning efforts and regulatory compliance strategies. Through the SCCWRP Commission governing board, SCCWRP works to build scientific consensus and unify its 14 member agencies and other environmental organizations around best-practices approaches for improving management of aquatic systems. Eight of SCCWRP’s member agencies are Southern California-based organizations that manage the discharge of treated wastewater effluent and land-based runoff into aquatic systems; the other six member agencies are water-quality regulatory organizations that oversee the activities of the dischargers. SCCWRP’s 14 member agencies collectively represent the preeminent group of organizations responsible for protecting Southern California’s coastal ocean and the watersheds that drain to it.