Lake Bam lies in the sub- Saharan country of Burkina Faso, near the small city of Kongoussi. Its broad, shallow waters yield fish and water for drinking, livestock, and irrigated crops and create a pleasant microclimate not far from the Sahara desert. More than sixty thousand people rely on it for livelihood and survival. Yet, like innumerable lakes, river basins, and aquifers all around the world, Lake Bam is drying up.
The lake, which is part of the Volta river system in West Africa, fluctuates naturally with the seasons, expanding when the rains replenish it and contracting as the fierce heat of summer drinks up to two- thirds of its shallow waters. Of late, however, the rains have been sparse and the lake has dwindled even more severely in summer, fragmenting into a chain of muddy ponds less than a meter deep. Soil eroded by farming and grazing in the surrounding catchment is filling it in, too much water has been taken from its feeder streams, and the local climate appears to be drying out. The waters once supported nearly a thousand hectares of irrigated crops, but these have dwindled to one hundred and fifty. The nets of fishermen often come up empty. Yet the main sources of income in this, one of the world’s most impoverished regions, are crops and fish.
On one level, Lake Bam’s story is that of the im mense challenges facing Africa and its people: its far larger neighbor, Lake Chad, which supports thirty million people, shrank to less than one- tenth of its former size over thirty years, and is forecasted to disappear completely by 2030. On another level, it illustrates what is happening to water around the world and foreshadows events that will affect every one of us as the century advances. In Hubei, China, once known as the “Province of a Thousand Lakes,” 815 lakes are said to have dried up by 2001.
“This year, the world and, in par tic u lar, developing countries and the poor have been hit by both food and energy crises,” Colin Chartres, head of the nonprofit International Water Management Institute (IWMI), declared in 2008. He continued, As a consequence, prices for many staple foods have risen by up to 100%. When we examine the causes of the food crisis, a growing population, changes in trade patterns, urbanization, dietary changes, biofuel production, and climate change and regional droughts are all responsible. Thus we have a classic increase in prices due to high demand and low supply. However, few commentators specifically mention the declining availability of water that is needed to grow irrigated and dryland crops. According to some, the often mooted solution to the food crisis lies in plant breeding that produces the ultimate high yielding, low water- consuming crops. While this solution is important, it will fail unless attention is paid to where the water for all food, fibre and energy crops is going to come from.
A farmer who faces a critical shortage of diesel fuel can resort to growing his own fuel crops or even use draft animals. But every form of food production, whether crop or livestock, on the farm or in the factory, depends on water. No water, no food. Food production is a thirsty business. Today food grown by irrigation uses about 70 percent of Earth’s readily available freshwater. The water we use in our homes and towns takes up 10 percent, while power generation and industry consume the remaining 20 percent. This 70:30 balance between rural and city use, however, is now changing as cities expand— and begin to swallow more and more of the farmers’ scarce water. Urban demand for water may soar by as much as 150 percent by 2025 as the cities themselves burgeon.
Irrigation has been practiced for at least eight thousand years and is a cornerstone of civilization because it enables one person to produce food for many. This underpins the growth of cities and industries. Irrigation has the great advantage over dryland farming that it can yield crops or pastures more reliably, especially in regions where rainfall is erratic. Today dryland farming uses about 5,000 cubic kilometers (1,219 cubic miles) of rainwater, while irrigated food production uses around 2,700 (658 cubic miles). Irrigation supplies 45 percent of the world’s food, however— and we may well need to increase this to 60 percent in order to feed eight billion people by 2025 and more beyond. The world is running out of water readily available to do this— at a time when global demand for food is set to double.
Resource Conflicts and World War III
