ABSTRACT
This chapter discusses the overdraft from aquifers and the overexploitation of water in river basins as a whole, as a result of the combination of groundwater and surface water consumption. It argues that the some national governments in Central Asia would need to agree on setting a cap on the blue water footprint in the Aral Sea Basin. The chapter explains the usefulness of setting a cap on the blue water footprint for the Lake Naivasha Basin in Kenya. The grey water footprint is a volumetric measure of water pollution, indicating how much water is needed to assimilate a certain pollutant load to water. From a global perspective, sustainability requires that maximum water footprint levels for all individual geographic areas are respected but, in order to achieve that, water-use efficiencies need to be improved everywhere, wherever feasible, also in regions where water is abundant.
