Robert Hirsch: Water is a very valuable resource to our nation. It’s important to our economy, to our health, our food supply, our energy supply, and the quality of our environment.
Robert Hirsch is a research hydrologist for the U.S. Geological Survey, or USGS. Dr. Hirsch spoke of a new report by the USGS that’s the most comprehensive on American water use, to date. The study analyzed data from 2005 to figure out how much water we use in America, today.
Robert Hirsch: We use about 410 billion gallons per day for the nation as a whole.
The USGS then compared the new report’s findings with past data, and discovered that Americans have done more with less water since 1975. Water use, per person, is down about 30 percent. Hirsch said this can be attributed, in part, to advances in agriculture and energy. That’s because most of the water an average American uses – up to 80 percent – goes into producing food and electricity. Hirsch talked about the more efficient use of water at power plants.
Robert Hirsch : Rather than just taking it out of a river, running it through the plant and discharging it, now they’re taking much smaller quantities and recycling them through cooling towers and cooling ponds. And that really decreases the overall environmental effect.
The report that Dr. Hirsch spoke of, “Estimated Use of Water in the United States in 2005,” required huge amounts of data supplied mainly from state governments.
Robert Hirsch: There is no national program to collect information on water use. Most water use information is collected at the state level, and the states are free to do that in whatever manner they wish. Some of them make great efforts to collect accurate information, some make much less effort. So there are in fact a lot of problems of inaccuracy of the information, and we’re working at the USGS to try and make some improvements so that we get more accurate information on water use.
He talked about water used for irrigation.
Robert Hirsch: There was tremendous rate of growth in irrigated agriculture up through about 1980. Since that time, it’s really leveled off and in fact declined slightly. The amount of water used per acre irrigated has actually been decreasing. Farmers have been conserving water, because it’s becoming more costly to lift the water from the groundwater aquifers, where they get the water, increasing cost of energy, which is used to pump that water, the overall depletion of the resources in some areas, and competition for water, particularly for urban uses in the west has actually caused a marked shift of the water moving out of agriculture and into urban uses. Farmers are also doing things to irrigate much more efficiently.
Hirsch spoke about urban water use.
Water use, per capita, in our cities has actually been very, very flat for the last 20 or so years. That’s because we’re using more and more water-saving appliances. We’re doing more metering of our water supply. We have rate structures that help to provide incentives for conservation. People, particularly in the southwestern part of the country, are doing new kinds of landscaping, such as zero-scapes, which enable them to have an attractive landscaping on their property, but not use so much water.
Our thanks to the US Geological Survey, celebrating the International Year of Planet Earth.
In his years with EarthSky, Jorge Salazar conducted thousands of in-depth interviews with scientists. He knows a lot about as diverse as nanotechnology, ecosystem-based management, climate change, global health, international environmental treaties, astrophysics and cosmology, and environmental security. Jorge currently works as a Technical Writer/Editor for the Texas Advanced Computing Center, which designs and deploys powerful advanced computing technologies and innovative software solutions for scientific researchers.