A study by the University of Texas at Austin Bureau of Economic Geology estimated that drilling and hydraulic fracturing in the Barnett Shale used 8.5 billion gallons of water in a 15-county region in 2011. The lead researcher, Jean-Philippe Nicot, said that while those water volumes are not negligible, they are “not much in the grand scheme of the water cycle.” The study estimated that statewide, hydraulic fracturing accounted for about 0.5 percent of total water used in 2011.

But are Barnett Shale natural gas wells a good use of water? We have to first ask what we get in return for that water. The natural gas produced through drilling and fracking is used by households to heat homes and water through electricity generators, and by industries to make thousands of products we all depend on, such as plastic, paint and fertilizer.

The most common use of natural gas is to generate electricity. Roughly half of the electricity in Texas is generated by natural gas-fired power plants. Seems like a pretty important use of our water.

But all energy sources require water; how does water use for natural gas production compare with other energy sources? It turns out natural gas is by far the most efficient user of water for energy production. The table shows that a unit (MMBTU) of natural gas takes only 1 to 3 gallons of water to produce. This compares to coal, which requires 2 to 8 gallons of water to produce one unit of coal energy. One of the most water-intensive energy users is fuel ethanol (from irrigated corn), which requires up to 29,100 gallons of water to produce one unit of energy.

To put it in perspective, here are some examples of water consumption in comparison to water used to produce natural gas:

• According to The Energy Collective: the biggest source of water consumption in the United States remains agriculture, which consumes around 32,850 billion gallons of water annually, or more than 243 times more water than fracking for shale gas.

• During the summer, one Texas golf course uses 4 million gallons of fresh water every eight days (or 22.5 days on an average during the year). Nationally, golf courses consume more water than all water used to hydraulically fracture all U.S. wells – about 0.3 percent of total U.S. freshwater consumption for wells vs. 0.5 percent for golf courses.

• Texas cattle consume 4 million gallons of water every 12.9 minutes, and the City of San Antonio consumes the same amount every 15.9 minutes. See the Texas Natural Gas Now infographic.

• Reported in The Wall Street Journal: In Texas, lawns and gardens consumed 495 billion gallons of water in 2010 (roughly 18 times more water than fracking does), according to a study published in November 2012 by the Texas Water Development Board. Nationwide, the Environmental Protection Agency (EPA) estimates that landscape irrigation consumes about 9 billion gallons of water a day. That's more than 3 trillion gallons a year, or more than 20 times the EPA’s highest estimate for the amount of water used annually in fracking.

• The Houston Chronicle reported that leaking water lines in Houston lost 22.4 billion gallons of freshwater in 11,343 leaks last fiscal year (nearly the same amount as used to hydraulically fracture all wells in Texas in 2011). 

• A study published in November 2012 by the Texas Water Development Board found that on average about 31 percent of residential water consumed in the state is used outside homes. In 2010, that amounted to 495 billion gallons. In 2011, according to the Bureau of Economic Geology at the University of Texas at Austin, fracking accounted for about 26.6 billion gallons statewide. So in Texas (a big state with arid regions), lawns consume roughly 18 times more water than fracking does.

Compared to other industries and other forms of energy, water used for natural gas production is still comparatively small (natural gas power plants use 50 percent less water than coal and 70 percent less water than nuclear plants). According to recent research, converting Texas’ coal-fired power plants to natural gas combined cycle power plants could reduce freshwater consumption in Texas by over 50 billion gallons per year – equal to 60 percent of total coal-fired, electricity-related consumption and enough to supply 1 million people (assuming 140 gallons of daily consumption per person). The study found that for every gallon of water used to produce natural gas through hydraulic fracturing, Texas saved 33 gallons of water by generating electricity with that natural gas instead of coal.

Another recent study by the Bureau of Economic Geology at the University of Texas found that switching power generation from coal to natural gas saves water and reduces drought vulnerability.

Our society is very dependent on energy, and energy requires water. Numerous studies have shown that natural gas is the most efficient user of water of all energy sources.