Are intra- and inter-basin water transfers a sustainable policy intervention for addressing water scarcity?

Water scarcity affects many countries around the world, and increases in severity over time as populations grow and climate change further intensifies. Governments and water regulators address increased water scarcity in a regional setting by introducing policy interventions, including non-structural, such as pricing mechanisms and quotas to affect demand, and supply management means, such as water storage and extraction. One of the most extreme policy interventions is to build infrastructure to move water from locations where it is abundant to locations facing scarcity. Such interventions are known as intra- and inter-basin transfers (IBTs) of water and have been quite frequently practiced in many river basins around the world in recent years. In moving water from one place to another benefits and costs are realized, some of which are private and some are public in nature. The objective of this paper is to discern whether or not the documented IBTs have been sustainable in addressing scarcity. Since very few quantitative cost benefit analyses are available for IBTs, we apply a variation of the QUAlitative Structural Approach for Ranking (QUASAR) method to 121 studies of documented IBTs within 40 territories and basins around the world, using five attributes of impact that were found to be associated with the transfers. Our findings suggest that the majority of the IBTs have been associated with overall negligible or negative impacts on the water-exporting regions, the water-transmitting regions, or the water-importing regions within the basins studied. Our findings also suggest that IBTs that were meant to relieve higher levels of water scarcity in the importing regions might be more prone to overall negative impacts