2. Increasing Demand
The agricultural sector, by far the largest consumer of freshwater resources, accounts for 70% global consumption. Irrigation consumes most of the water in the agricultural sector, and has become an integral part of modern civilization because of access to groundwater aquifers. Once farmers were freed from relying on rain to water their crops, highly efficient commercial farming became increasingly common. This innovation also underpinned the Green Revolution, which dramatically increased crop production throughout the third world in the 1960s. Unfortunately, water is being drawn from many of these aquifers faster than it is being replaced.
The industrial sector accounts for 22% of global water consumption; this number will grow in the coming decades as the developing world industrializes. The needs of industry tend to take precedence over agriculture for simple economic reasons. 1,000 tons of water will produce 1 ton of wheat, which is worth $200. 1,000 tons of water in the industrial sector, however, will generate $14,000 worth of goods. On a per ton basis, industry creates 70 times more wealth. Despite its economic benefits, intense water use by industry has led to serious pollution that is beginning to create problems worldwide.
The residential sector uses the remaining 8% of the total water supply. Although this sector only accounts for a small percentage of overall use, it always takes precedence over industry and agriculture. In the last fifty years the world’s urban population has exploded, and by 2010 50% of the people on the planet will live in cities. In addition to the simple increase in population, per person consumption of water has risen. As more people begin utilizing modern luxuries like flush toilets, showers, and washing machines, the demand created by the residential sector will increase dramatically.