Sustainable water and land use planning is an important component of regional planning. Regional planning, as a multi-sectoral concept, serves as a framework for sub-regional and local planning. Water and land use planning needs as comprehensive a system understanding as possible, of water and land uses. This forms the basis for managing water resources quantity and quality, in coordination with the existing land use. The developed systematic GIS-based planning approaches, for a sustainable water allocation and water quality conservation, as well as the resulting recommendations for actions, supports water management on a regional and local planning level. The developed concepts are illustrated by up-to-date project results of the R&D research projects “ViWaT-Planning” Stolpe et al., in the Mekong Delta in Vietnam and “iWaGSS” Jolk et al., in the Olifants River Basin in South Africa. Both R&D projects are funded by the German Federal Ministry of Education and Research (BMBF) and are coordinated directly with existing water management institutions and their measures in both countries. The focus of this publication will be on the general methodology of planning support, in the fields of water and land use.