Water and world population growth

Freshwater is renewable but finite. Over the next 50 years, world population growth will reduce the renewable water supply per capita by approximately one third. By 2025, an estimated 3 billion people - 38 percent of the projected global population - will live in countries classified as water-stressed. In many regions, numerous signs that water use is not sustainable are already in evidence in the widespread overpumping of aquifers and excessive depletion of river flows. Meeting the water demands of 8 - 9 billion people while at the same time protecting the health of the aquatic environment will greatly challenge water professionals. This article makes the case for a new water management paradigm - one that strives to balance water's economic and ecological functions. A key to success is increasing water productivity, i.e., doing more with less water.