The principal activities of South African researchers in hydrology and water resources during the reporting period have been concerned with ground- and surface-water interactions, rainfall-runoff modelling, and the establishment of improved regional water resource databases, the management of transboundary water resource systems, the ecological reserve, and quantifying the impacts of streamflow reduction activities. Most of these studies have focused on supporting the radically new provisions of the National Water Act of 1998. Keywords: Streamflow reduction, Water resources, Hydrological sciences.