Pressures on water supply are the world’s second most urgent development challenge. A standard tool for measuring how well countries are managing their water resources can overcome global crises.
Water management lies behind most of the great development challenges of the 21st Century. It's obvious but we too often forget that we won't be able to achieve food security, energy security, healthy cities and productive ecosystems without greatly improving how we manage water. In the global north, the challenges of basic access to water services are less pressing than they are in the south but -- as hurricane Sandy showed New York -- the challenges of making the right quantity and quality of water available where it is most needed still loom large.
And the service and resource sides of water are increasingly linked. In rural India, water availability or quality is a more prevalent reason for failure of water supply infrastructure than lack of maintenance.
So the idea of a global goal on water, capturing water resource management and water supply and sanitation services, makes sense. Measurement is key. Millennium Development Goal 7 made a huge contribution by getting everyone to come together around a common definition of what we mean by ‘access to safe water’ and ’access to basic sanitation’ and giving us numbers -- however imperfect -- that we can all use.
Now it is time to do the same for water resources as well. Improving water management will involve grasping politically tough nettles. Reducing the allocation of water to some uses, stopping pollution, stopping people overdrawing aquifers is needed, but not easy.
And the difficulties are compounded when the choices have to be made across international boundaries. Yet when there is no standard, publicly available, set of measures to tell us how much water we have, or how and where it is used, it is easy to put off making those tough decisions or to make bad decisions.
Yet how do you measure something with so many dimensions? When having too much is as problematic as having too little? When averages and extremes both matter. And where nature plays such a huge part? The simplest indicator -- m3 of water per capita -- will always leave us with sparsely populated Greenland and steamy Democratic Republic of Congo at the top, and dusty Kuwait near the bottom. It takes no account of how well countries manage their natural endowments. Another common indicator -- number of people living in water scarce countries -- has two disadvantages. It is easily misinterpreted to mean that people go thirsty when in fact it shows whether they live in a country that has enough water for all its needs, including to grow all its own food and thus the extent to which they depend on food trade. Again it does not measure how well that country shields its people from a basic fact of nature.
In my view, we want to measure two things:
1. The extent to which countries limit overall water consumption to sustainable amounts.
2. How well countries manage risks associated with water.
For the first, my favourite indicator is the number of people or share of the GDP located in basins that are over-using water. It has the advantage of being understandable to everyone, and of taking account of surface and groundwater use. Remote sensing techniques have come on so far now, that we could measure that by total evaporation and transpiration divided by total rainfall and aquifer inflows into that basin over an average of, say, 10 years, and map population and economic activity to each basin. It would use the same methodology everywhere and not require country level surveys or samples.
For the second measure, we would need some sort of composite risk index, which many different organizations are developing.
In Davos last month, the World Economic Forum's global risks report listed water supply crises as the number two risk in terms of impact, ahead of spread of weapons of mass destruction and food crises and fiscal imbalances. As the world is waking up to the potential problems water management poses to so many aspects of life, the chance to come together on a standard tool to measure how well countries are managing the resource is too important to pass up.