The development of uranium mining in the arid Erongo region of central western Namibia has increased pressure on limited water resources. An assessment of available water resources and demand from different stakeholders was carried out. An Integrated Geohydrological Model (IGHMS) was developed. IGHMS produces time series of key hydrological processes such as channel flow, evapotranspiration, transmission losses, lateral subsurface flow and water level of aquifers in key compartments used by mines and other stakeholders in the region. The model uses an explicit visual modelling approach. This approach facilitates model maintenance and integration of stakeholder actions. IGHMS is a framework model. For important aquifers or aquifer compartments more detailed numerical groundwater models have been developed. IGHMS assures the consistency of boundary conditions. The results of IGHMS have led to a new monitoring and licensing strategy in the uranium province of the Erongo Region. Keywords: strategic environmental impact assessment, integrated geohydrological model, aquifer compartment, regional/basin model, water resources allocation, new monitoring and licensing strategy.