Water scarcity is a basic problem in many regions of the world. The consequences of this are black markets for drinking water, unauthorised water extraction from private wells, and the uncontrolled decline of groundwater supplies. For Jordan, one of the world’s most arid countries, a team of international scientists coordinated by the Helmholtz Centre for Environmental Research (UFZ) has analysed the role of water markets and discusses the increasing dependence of the population on illegal water trade in an article published in Nature Sustainability. The article identifies solutions with which the state would be able to stabilise the supply of water in the face of climate change.