Imported water risk: the case of the UK

Arjen Y Hoekstra,Mesfin M Mekonnen

doi:10.1088/1748-9326/11/5/055002

Abstract

While the water dependency of water-scarce nations is well understood, this is not the case for countries in temperate and humid climates, even though various studies have shown that many of such countries strongly rely on the import of water-intensive commodities from elsewhere. In this study we introduce a method to evaluate the sustainability and efficiency of the external water footprint (WF) of a country, with the UK as an example. We trace, quantify and map the UK’s direct and indirect water needs and assess the ‘imported water risk’ by evaluating the sustainability of the water consumption in the source regions. In addition, we assess the efficiency of the water consumption in source areas in order to identify the room for water savings. We find that half of the UK’s global blue WF—the direct and indirect consumption of ground- and surface water resources behind all commodities consumed in the UK—is located in places where the blue WF exceeds the maximum sustainable blue WF. About 55% of the unsustainable part of the UK’s blue WF is located in six countries: Spain (14%), USA (11%), Pakistan (10%), India (7%), Iran (6%), and South Africa (6%). Our analysis further shows that about half of the global consumptive WF of the UK’s direct and indirect crop consumption is inefficient, which means that consumptive WFs exceed specified WF benchmark levels. About 37% of the inefficient part of the UK’s consumptive WF is located in six countries: Indonesia (7%), Ghana (7%), India (7%), Brazil (6%), Spain (5%), and Argentina (5%). In some source countries, like Pakistan, Iran, Spain, USA and Egypt, unsustainable and inefficient blue water consumption coincide. We find that, by lowering overall consumptive WFs to benchmark levels, the global blue WF of UK crop consumption could be reduced by 19%. We discuss four strategies to mitigate imported water risk: become more self-sufficient in food; diversify the import of water-intensive commodities, favouring the sourcing from water-abundant regions; reconsider the import of water-intensive commodities from the regions that are most severely water stressed altogether; and collaborate internationally with source countries with unsustainable water use where opportunities exist to increase water productivity.

Highlights

Since the beginning of this century there is a growing awareness that freshwater is a global resource, even though freshwater is still mostly considered and managed as a local resource (Hoekstra 2011, Vörösmarty et al 2015)
By lowering overall consumptive water footprint (WF) to benchmark levels, the global blue WF of UK crop consumption could be reduced by 19%
About 55% of the unsustainable part of the UK’s blue WF is located in six countries: Spain (14%), USA (11%), Pakistan (10%), India (7%), Iran (6%), and South Africa (6%). On this list come France, Israel and Egypt. These countries can be considered as the hotspots of concern from the UK consumer perspective, because the UK’s economy significantly relies on the water resources in these countries while the water consumption in the specific regions within those countries where export products for the UK are produced is not sustainable

Summary

Introduction

Since the beginning of this century there is a growing awareness that freshwater is a global resource, even though freshwater is still mostly considered and managed as a local resource (Hoekstra 2011, Vörösmarty et al 2015). This is very different from oil, which is broadly perceived as a resource of strategic international importance. In the case of freshwater, dependence on external water resources is still under the radar for most governments. Clark et al (2015) find a global trend towards an increased dependence on foreign water resources between 1965 and 2010. Suweis et al (2013) show that international water dependencies as they exist cannot be assumed to continue into the future given growing water scarcity (WS) in the

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