In the American West, there is no more sure way to get an argument than to present a plan to divert water from one river basin or underground aquifer and pump it to another. It’s called “trans-basin diversion” and inevitably the people in the area supplying the water are irate that someone else would even consider taking “our” water.
Recently, a Canadian firm called the Medusa Corporation was formed to promote the idea of filling huge latex bags with fresh water in water-rich areas of the world and towing them through the ocean to dry areas. The bags would up to seven football fields long – 650 meters long by 150 meters wide – and would hold almost two million tons of water. So far, they haven’t found any buyers or sellers, but they’re still trying.
But as Sandra Postel has suggested, there is an alternative way of exporting water that’s been used for thousands of years – exporting grain.
Her contention is based on the fact that 70 percent of the fresh water that’s used in the world goes to irrigate crops for human consumption and meat production. Also, since it takes 1,000 tons of water to grow one ton of grain, it’s 1,000 times more efficient to import grain to a water-hungry country than to import water. Countries can, in effect, make up for water deficits by purchasing grain from other countries rather than growing it themselves.
Geographer Tony Allan of the University of London has called grain “virtual water.”
Some economists suggest that water-poor countries can generate more income from their limited water by using it in commercial and industrial production and buy the “virtual water” they need for food as grain on the international market. Now, 34 countries in Africa, Asia and the Middle East are considered water-poor. All but two of them – South Africa and Syria – import more grain than they grow. And 24 of the 34 import at least 20 percent of their grain. Together, water-stressed countries import 50 million tons of grain out of the total worldwide grain exports of 200 million tons.
In other words, water scarcity is, to some degree, driving about one quarter of the global grain trade.
However, when water wars and the boom and leveling out of irrigation are considered, we may be reaching the limits of growth in agricultural productivity while population continues inexorably. Water has been left out of the food security debate. Water wars – the competition for water – may spill over into international competition for grain. If that happens, the poor, food deficit nations will lose out.