Projecting and valuing domestic water use at regional scale: A generic method applied to the Mediterranean at the 2060 horizon

The present work focuses on the demand side of future water scarcity assessment, and more precisely on domestic water demand. It proposes a quantitative projection of domestic water demand, combined with an original estimation of the economic benefit of water at large scale. The general method consists of building economic demand functions taking into account the impact of the level of equipment, proxied by economic development. The cost and the price of water are assumed to grow with economic development.The methodology was applied to the Mediterranean region, at the 2060 horizon. Our results show the evolution of water demand and value, measured by surplus, over time. As long as GDP per capita and water price remain low, demand per capita increases along with economic development, and surplus per capita increases with demand. As demand approaches saturation, the combined negative effects of water cost and price increase on surplus grow stronger, and surplus per capita begins to decrease.The developed methodology is meant to be used for large-scale hydroeconomic modelling, in particular for regions with heterogeneous levels of development and low data-availability.