In the United States we have an abundance of water. The country has 4.5 percent of the world’s population yet almost 8 percent of its freshwater resources. It is home to the largest freshwater lake system in the world, the Great Lakes, which holds 6 quadrillion gallons of water (that’s a 6 followed by 15 zeros). And the mighty Mississippi River flows at 4.5 million gallons per second at its mouth in New Orleans, supplying water to about 15 million people.
As vast as the United States' water resources are, they aren’t endless. We need to protect and conserve them, especially given that the average American water footprint, or the total amount of water directly and indirectly used, is nearly twice the world’s average. Major bodies of water like Lake Mead and the Ogallala Aquifer have experienced significantly reduced water levels because human demand has outpaced natural availability. Droughts, which can quickly diminish water supplies, can happen anywhere. For example, in September 2007, nearly half the country was in a drought. In addition, climate change will continue to impact water supplies by altering precipitation patterns. In fact, a recent report by the Natural Resources Defense Council found that 70 percent of U.S. counties could face water shortages by 2050 because of climate change, population increase and economic growth. This has major implications for how we use water in the United States.
The United States Geological Survey estimates that (as of 2005, the most recent year for which data is available) we withdraw 410 billion gallons of water a day, including both fresh and saline water. Most (80%) of these withdrawals go to thermoelectric power plants (for cooling) and agriculture (for watering crops). Another 11 percent (about 44 billion gallons of water) go to municipal supply and ultimately treatment systems each day (by the way, moving and treating that much water requires massive amounts of energy).
This water, some of which runs through our showers and sinks, is potable, which means it is clean enough to drink. Most of it, however, goes for uses that don’t require potable water, such as watering the lawn and flushing the toilet. It is also used for commercial and industrial purposes, producing the goods and services we use every day. Clearly comprehensive water conservation goes beyond saving water at home.
In order to really conserve water we have to conserve everything else, from the food we eat to the clothes we buy to the energy we use to power our homes. This means changing the way our water, wastewater and energy systems work, and changing the way we think about, use and consume everyday items and services.
The Ogallala Aquifer is an enormous underground water source stretching across eight states in the American West and was once thought to be virtually bottomless. Unfortunately, it’s not. Since intensive irrigation began in the 1950s, the aquifer has lost nearly 10 percent of its total volume. More water is being pumped out to irrigate crops in the High Plains region than is returned naturally to the aquifer through rain fall and snow melt.