Due to the intergovernmental nature of the nexus assessments under the Water Convention, official data originating from national authorities are used as much as possible. Countries tend to trust their official data and nexus assessments are reviewed by the Governments, hence transparency about the sources used is necessary. Using databases with an official source (e.g. FAO, OECD, World Bank, ECE) can save time, turning the request for data into a request for validation.