The global water supply/demand imbalance is increasing. This is due to population growth, particularly in arid, water-short regions, contamination of water sources, and inefficient utilization of available supplies. Increasingly, futurists are predicting a world where water shortages, exacerbated by global warming, could cause increased food imports, population shifts, domestic political unrest, and geopolitical conflict. As the potential for future crisis rises each year, calls to address water supply issues are becoming more urgent, though political action to change these trends has so far been muted.
Here are a few facts about water supply and use (gleaned primarily from the World Resources Institute, the United Nations Environment Program, and the Center for Strategic and International Studies).
- Water supply is recirculated through the atmosphere, but no “new” water is being created
- Only 3% of the earth’s total water supply is fresh water, versus salt water, and the majority of fresh water is inaccessible
- 1% in surface water, such as rivers, lakes, and streams
- 29% in underground aquifers, which are being over-pumped beyond their recharge capability in many regions
- 70% in frozen glaciers
- 15-35% of agricultural water withdrawals are in excess of sustainable limits
- Water production lost due to leakage, theft, and inadequate billing practices is typically 40-50% in developing countries, and may be 10-30% in developed nations
- Industrial withdrawals are expected to rise by 55% by 2025
- Despite efforts by global governments, nearly 1.1 billion people still lack access to water supply service and 2.6 billion people lack access to sanitation, mostly in Asia and Africa
- About 5 million people die every year from water-related illness
- By 2050, untreated wastewater could contaminate one-third of global annual renewable freshwater supplies
- The world’s population has tripled in the 20th century – but global water use has grown six-fold
- Another 40-50% in population growth is expected within 50 years, along with increasing urbanization and industrialization, with the fastest growth taking place in water-short areas, including the American Southwest, China, and India
- In 1995, over 400 million people lived in countries experiencing water stress or water scarcity
- By 2025, that number is expected to rise to 4 billion – over half the world’s
population 50% of global population growth is expected to take place in water-stressed countries - China’s demand for water is expected to increase 400% by 2030
- China’s population is 21% of the world and is increasing 1%/yr, yet China only has 7% of the world’s water. 400 of China’s 660 main cities face water shortages one-third of rural residents drink unsafe water
- By 2020, India’s demand for water is expected to exceed all current sources of supply
- 70% of irrigation and 80% of domestic water use comes from groundwater, which is rapidly being depleted. 15% of aquifers are in critical condition this is expected to grow to 60% in 25 years
World Resources Institute
Annual Renewable Water Supply Per Person By River Basin, 1995
World Resources Institute. 2000. EarthTrends: Environmental Information. Available at http://earthtrends.wri.org. Washington DC: World Resources Institute
Areas with per capita water supplies below 1,700 m3 per year are considered under “water stress” below 1,000 m3 per year are under “severe water stress”
Assuming current consumption patterns continue, by 2025, at least 3.5 billion people will live in river basins under “water stress,” with 2.4 billion of them in “high water stress” areas – including the Colorado River basin in the U.S.
