Sustainable and efficient water use: from water footprint accounting to setting targets

Abstract

Humans consume freshwater in all sectors of the economy and across all layers of society. Demand on already stressed water systems is growing, hence the challenge is for humanity to strike a sensible balance in allocating limited freshwater resources to the various demanding and often competing uses, without compromising nature. This thesis examines two policy instruments that are particularly promising to help transition to sustainable and efficient use of freshwater worldwide. The first, pertaining to sustainable consumption, is setting water footprint (WF) caps at the river basin level. Setting caps aims to prevent overshoot of limited natural endowments and to reconcile human freshwater appropriation with conservation. The accompanying study quantifies WF caps for all river basins in the world and provides an estimate for humanity’s safe operating space in terms of freshwater consumption. The second, pertaining to efficient water use, is formulating WF benchmarks for water-using activities. A benchmark identifies a ‘reasonable’ WF per activity, that can serve as reference level. The first accompanying study quantifies WF benchmarks in global crop production, and reveals that large water savings are possible if producers would reduce their WFs to benchmark levels – particularly in already water scarce basins. A second study estimates WFs of manmade reservoirs worldwide for hydroelectricity generation, irrigation, residential and industrial water supply, flood protection, fishing and recreation, to find that reservoirs are large water consumers that add substantially to humanity’s blue WF. A third study moves from a global to a local perspective. For a case study in Malawi, the research assessed various water and land indicators to help local farmers choose what crops to grow. The last study combines sustainable and efficient water consumption targets in a framework that is applied to institutional investors – an under-emphasized yet influential actor group. The study assesses to what extent investors incorporate water sustainability targets in their investment decisions. The assessment reveals that concerns over widespread water scarcity are largely invisible to them, while proposing improvement actions. The studies and rich datasets thus brought forward help boost the transition to sustainable and efficient use of freshwater resources worldwide.