Water, water everywhere?
Clean, fresh water. Especially in the U.S., we have taken it for granted. But recently, from Atlanta to Australia people have come to blows over water, their violent behavior triggered by supplies dwindling in the face of increased demand and shortages sparked by regional drought. Projections show that by 2025, as many as fifty countries will face water shortages affecting nearly 40% of the people on earth. In the U.S., a recent survey found that at least 36 states expect local or statewide shortages by 2013.
Water covers some seventy percent of the Earth’s surface, but only about 3% of that is freshwater – and most of that freshwater is unavailable, locked in polar ice caps or glaciers or hard to reach underground. The relatively tiny portion we can access is not evenly distributed across the globe because of the uneven nature of the water cycle.
Water evaporates into the atmosphere, and is redistributed when it returns to earth as precipitation. Rain and snow fall in widely differing amounts, depending on time and place. We depend on precipitation to replenish supplies of both surface water – from rivers, streams, and lakes – and ground water. Some groundwater refills rivers and streams, and some recharges underground aquifers. Unfortunately, water is not always available when and where people need it.
Meanwhile, a growing and increasingly industrialized world population draws more and more on this finite resource. The U.S. population doubled from 1950-2000, but the demand for water more than tripled. Water withdrawal has ripple effects for human health and the environment. When water levels go down in lakes or reservoirs or aquifers, contaminants ranging from naturally occurring arsenic to chemicals from agricultural runoff can accumulate in higher concentrations. That’s bad for people, and also for delicate ecosystems and the creatures that inhabit them.
