Closing the Gap Between Water Needs and Renewable Water Supplies: Global Perspective, Local Lessons

The annual supplies of renewable freshwater in any given region are on average stable or even declining due to climate change. Yet, the water needs for subsistence (drinking, cooking, washing, hygiene), food and fiber production, and support of ecosystems grow with population and rising living standards. In many regions, these trends give rise to growing gaps between needs and natural water supplies, with dire human and environmental consequences. By 2050, more than five billion people in over 80 countries will experience water scarcity (below 1000 cubic meter of freshwater supply per person per year) and about three billion will experience absolute scarcity (below 500 m3 per person per year). After providing a global outlook of freshwater “gaps”, I discuss how they can be managed, drawing on recent lessons from Israel’s water economy. I consider in particular a combination of demand and supply management tools. Demand management relies on pricing and quotas interventions combined with a limited use of market-based mechanisms. Supply management entails increasing the water supply by developing recycling and desalination sources. The Jordan River Basin, comprising Israel, Jordan and the Palestinian Authority, serves as a case in point to illustrate how this water management approach can close the water gaps in a region that experiences extreme (subsistence) water scarcity conditions.