Watershed improvement: The upstream – downstream question

If we utilize our water better upstream, what will happen downstream? Will water availability decrease? Is watershed improvement a zero-sum game with the gains upstream deducted from the situation downstream, or is it an overall system improvement? Or if we take a broader view of water-related ecosystems services, how does more intense upstream water use have an impact on all relevant ecosystem services in the entire area? Who are the winners and who are the losers? Frank van Steenbergen, Tesfa-alem Gebreegziabher Embaye and Eyasu Hagos take a crack at answering these questions.