Virtual Water: Accounting for Water Use

Following on from my last blog on the discovery of a massive aquifer under part of Namibia I thought it might be useful to consider a key accounting concept for water resources: virtual water. The term ‘virtual water’ was coined by Tony Allen of SOAS and and refers to the invisible water, the water that it takes to produce the food and goods we consume or as Virtual Water puts it


‘Virtual water is the amount of water that is embedded in food or other products needed for its production.’

(Other websites on virtual water include: Virtual Water)
Some of the figures involved are quite amazing. A kg of wheat takes 1,000 litres of water to produce, a cup of coffee takes 140 litres, 1kg of rice takes 3,400 litres and 1 car takes 50,000l litres of water to produce. You can even work out your own water footprint using the calculator on the site. There is even an app for your mobile! Additionally there is information on national water footprints and, importantly, the idea that virtual water is traded between nations.

Mekonnen and Hoekstra (2011) at the University of Twente published a UNESCO report on the issue of virtual water over the period 1996-2005. They divided virtual water into three colours: green, blue and grey. Green water is the water associated with agricultural production, blue water is that associated with industrial production whilst blue water is the water associated with domestic use. From their analysis they calculated that the global average water footprint for consumption was 1385 m3 per year per capita, with industrialized countries having a footprint of 1250-2850 m3 per year per capita, whilst developing countries had footprints in the range 550-3800 m3 per year per capita. The low values represented low consumption volumes in these countries, whilst the large values represented big water footprints per unit of consumption.

Their key conclusions were that about 20% of the global water footprint for that period was related to production for export. This means that there are large international flows of virtual water with some countries importing virtual water (2320 billion m3 in the time period). In countries where water is scare there is a tendency to import large amounts of virtual water in food and agricultural products, saving national water resources for key uses that add greater value such as industrial production. Tony Allen makes an argument in 1997 for the Middle East being one of the first regions to develop this adaptation to resource scarcity. The relatively large volume of international flows in virtual water generated water dependencies that they suggest strengthen the argument that issues of local water scarcity need to be considered within a global context.


The significance of this concept for the discovery of the aquifer and its use is that the Namibian reserve has to be viewed within a global context. The development of agriculture and the technical development of the resource are likely to be political decisions and increasingly likely to be geopolitical decisions that have to take into account the regional position of Namibia, the likely trade partners for the virtual water, the geopolitical power of potential partners and the future frictions that could arise as environmental change affects the current international demands and flows of virtual water.

Namibian Aquifer: Who Benefits?

A recent BBC article reported on the discovery of major aquifer in Namibia. The new aquifer is called Ohangwena Il and it covers an area of about 70x40km (43x25 miles). The project manager, Martin Quinger, from the German federal institute for geoscience and natural resources (BGR) estimates that the 10,000 years old water could supply the current water consumption needs of the region for about 400 years.


The find could dramatically change the lives of the 800,000 people in the region who currently rely on a 40 year old canals for their water supply from neighbouring Angola. Martin Quinger states that sustainable use is the goal, with extraction ideally matching recharge. The easy (and cheap) extraction of the water under natural pressure is complicated by the presence of a small salty aquifer that sits upon the top of the newly discovered aquifer. Quinger states that if people undertake unauthorised drilling without following their technical recommendations then a hydraulic short-cut could be formed between the two aquifers contaminating the fresh water.

In terms of the use of the water he comments that:
‘For the rural water supply the water will be well suited for irrigation and stock watering, the possibilities that we open with this alternative resource are quite massive’.
The EU funded project also aims to help young Namibians manage this new water supply before their funding runs out.
The discovery is a great, potentially life-changing resource for the region but the question that arises in my mind is who is going to benefit from this discovery? The current socio-ecological system in the region is attuned to the amount of water available. The availability of more water could change this but will it be for the benefit of the current population? A key aspect is the last point made about the EU funded project – the management of the resource by those in the region. The skills required to manage a large water resource are context dependent. They depend on the uses to which that resource will be put. They require technical and resource allocation skills that presume a context of educational levels that are embedded within a culture and location. Acquiring these skills takes a while as people go through the appropriate training and gain the experience that helps management of this resource. If this expertise does not exist now within the region then the implication is that external support will be needed and, by implication, paid for.

Another issue is the assumption that the water will be used for improving agricultural production which I assume (maybe wrongly) means more intensive agriculture. The key questions are then what type of agriculture and what additional resources are required to ensure that it works? Thinking of the whole agricultural system as a complex network of relations, the question really is what network of relations will be overlaid onto the existing agricultural network to ensure the success of the new type of agricultural production. A more intensive agriculture implies fertilizers, investment, technical know-how as well as access to markets, regional, national and international, so that funds can be extracted from the new produce. Again is it likely to be the regional population that is able to conjure up the finance, technical knowledge and all the other bits of the network required to develop this new agriculture? In time, the answer might be yes, but will external agencies, such as the government and investors permit this time before developing the valuable resource?

This problem with development as seemingly envisaged by the project is illustrated in the comment concerning extraction. The implication is that only people with a specific level of technical ability can extract the water. This implies that a system of permits is likely to be implemented and so access to the resource will be controlled and restricted. It also implies that the permits will be allocated to operators able to meet the technical requirements outlined by the project, and if this expertise does not exist within the region then the operators will have to be external contractors. This system is likely to require financing so value will have to be extracted from the supply of water. To who will the funding flow and who will pay for it? How will the regional population receive the water and what will the price of the water? I would like to hope that the EU funded project will enable the management of the resource by the regional population for the benefit of that population in the manner that that poplulation sees fit for their own development.