Water Resource Management (WRM) in semi – arid areas has been and is continuing to be challenging, especially in Africa where climatic variability is extreme and vulnerability is high. In the context of changing climate and growing population, pressure on both green and blue water resources is expected to increase significantly in the future. To mitigate impacts, financial mechanisms have to be found that allow sustainable management and protection of biodiversity, water resources and the Ecosystem as a whole. In the research project ‘CERPA – Certification of Protected Areas’ the practicability of an international market system for protected areas is evaluated. As an example for the case study, wetlands and floodplains in Namibia and Tanzania were chosen. Both Ecosystems are known to be amongst the most productive and valuable (in terms of Ecosystem Services provision), but also most vulnerable Ecosystems that are expected to be highly impacted in the future which makes them an ideal focal point for such an interdisciplinary research.