By: Hans Poschman, CSG-WEST Policy Analyst
Since 1950 the United States Geological Survey (USGS) has produced water use reports every five years to give a detailed look at how the United States uses water. The most recent USGS estimates show that in 2005 average water withdrawals was about 410 billion gallons per day (BGD) from fresh and salt water sources. Forty-nine percent of those withdrawals were for thermoelectric power and thirty-one percent was for agricultural uses. Domestic uses (indoor and outdoor residential uses, such as drinking water, sanitation, and lawn watering) accounted for just over 7% of total withdrawals. While the data does not distinguish between consumptive and non-consumptive uses, it gives a clear picture of how much water we use and just how important water is to the everyday functioning of our society.
There are vast differences in water usage from state to state that often corresponds to their geography. Coastal states like California, Florida, and Connecticut are able to use salt water for most of their thermoelectric power needs which reduces their dependence on fresh water resources. States like Oregon and Idaho benefit from the many hydroelectric facilities throughout their region and use little water for electrical generation. The USGS considers water used to create hydroelectric energy to be in-stream flows and does not count it in its calculations.
Per capita domestic water usage also varies greatly from state to state. Maine uses the least at only 54 gallons per person per day, while Nevada uses the most at 190 gallons per person per day. According to the 2005 USGS data, every Western state except for Alaska uses more than 100 gallons of water per person per day. Some of this differential in water use can be easily explained by climate differences. For example, areas of the country with greater precipitation required less water for lawns and gardens compared to desert communities in Arizona, California and Nevada.
Since 1985 total daily water usage has remained consistent between 399-410 BGD. This is despite a population that has grown from 237 million in 1985 to 297 million in 2005. Water conservation is making a difference. In 1980 the US used 1.980 gallons of water per person every day; in 2005 that number had dropped to 1,383. As population continues to grow - the US Census Bureau projects that the US population will cross the 400 million mark in 2051- we will face additional pressures on our water supplies that will require the US to find new water supplies, further reduce consumption or both.
For more information on the Water & Environment Committee, please contact CSG West staff: Luis Tapia by phone at (916)553-4423 or email: email@example.com