Improving the efficiency of water use: at the right place, at the right time, in the right form

By Peter Brabeck-Letmathe

07 July 2016 See comments (0)


My last post here was about the urgency, and about the need for ambitious goals for improving the efficiency of water use without affecting the growth in prosperity. And the closing remark made clear that matters in water are particularly tricky. There is a major difference compared to CO2: in the case of water it is not just about litres anywhere in the world and at any time, it is about savings

    at the right place,
    at the right time and
    in the right form.

Rather than trying to provide a comprehensive view, let me illustrate with a few ideas ad examples, meant to stimulate the discussions. Anyway, there is no universal recipe.

I will start with the first aspect, ‘at the right place’. Freshwater savings are only relevant if happening in a watershed with overdraft. Savings in water abundant countries such as Germany or Switzerland may help to lower your municipal water bill, but will have, in general, no impact whatsoever on the global water situation. The same applies for different river basins in a country. Saving water in the Brahmaputra basin with its surplus will, in general, only increase the amount of runoff, while savings in the neighbouring Ganga basin, on the Indian subcontinent, are very urgent (see chart from the first report of the 2030 Water Resources Group).

india map

Another, more general point: the higher up along a watercourse water is being saved, the higher the probability that there are users afterwards.

Next aspect, ‘at the right time’. Saving water at a time when water is over-abundant, e.g., during monsoon, again is mainly increasing runoff, at times even to the detriment of those living close to a river. Actually, during periods of over-abundance, withdrawing and using water even gets a positive value for the community. This is by no means an academic concept. Paddy fields (see picture above) store the water at the time of heavy rain, and gradually discharge the water into downstream rivers and surrounding areas, thereby preventing or mitigating the damage caused by flood. The Bureau of Water and Soil Management of the government of the Philippines estimated (pdf, 2Mb) in a study the value of this flood prevention in an order of magnitude of some 13% of total value of production. In other words, water withdrawn to grow the rice has a positive value for the farmers, but in times of heavy rain, their withdrawals become a service to community. Maybe, farmers should be paid for this service.

Finally, ‘in the right form’. This includes availability and water quality. Saving water that is not readily available, or polluted and therefore of no productive use for subsequent water users, does not really have the desired impact. Another aspect has to do with the often quoted US water savings since the turn of the century. Between 2005 and 2010, according to US government’s Geological Survey (USGS), the thermoelectric power sector was responsible for the largest decline, cutting withdrawals from 12.6 billion gallons per day in 2005 to 6.6 billion in 2010. Indeed, US power plants today are using less water to cool equipment and some water-intensive facilities have been shut down. However, it has also been pointed out that most power plants in coastal states such as California draw cooling water from the ocean, and so a major part of the decline could come from a cut in salt water withdrawals, not freshwater.

In conclusion: Again, a substance that, at first sight, looks as simple as water, becomes complicated and highly complex when being used in society and to drive prosperity. There are no ready-made solutions to overcome the complexity, but maybe perspectives, such as value of water used per unit of value-added of goods and services. At least in theory, free and open markets (here it would be about markets for tradable water usage rights such as in Oman, undistorted trade of agricultural products also strengthening water efficiency through trade of embedded water across borders allowing water-poor countries to implement the concept of comparative advantage, etc.) are the best way to turn complexity into efficiency. While in other posts here on my blog I pointed to some practical and institutional difficulties with such market-based concepts, I still think it is something we should look into in the longer term.

Readers of my blog, no doubt, have more ideas. As ever, I welcome your comments.

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