Visualization: Top 10 Texas Counties for Fracking Water Use

Newly released data suggests that oil and gas companies may not have enough water to continue fracking at the current rapid pace in drought-stricken South Texas, where population growth is also creating a strain on water supplies. 

Ceres, a Boston-based sustainability advocacy group, recently released a study with some of the most comprehensive data to date on the volume of water used for fracking in various oil and gas-rich areas nationwide. Below is data for the 10 counties in Texas where energy exploration companies used the most water for fracking during 2012, compared to the amount of total water used by those counties in 2011. Total county water usage data is not yet available for 2012 from the Texas Water Development Board.

The amount of water used for hydraulic fracturing in Texas is less than 1 percent of the state's total water use. But in at least one county, the amount of water used for fracking in 2012 was more water than the entire county used in 2011. And in other counties, fracking water use in 2012 equaled at least half of the county's water usage in 2011. 

In billions of gallons:

The first five counties in the chart, along with Gonzales County, are all in South Texas' Eagle Ford Shale, where drilling activity is increasing daily. In McMullen County, where the population is less than 1,000, more water was used for fracking in 2012 than the entire county used in 2011. The share of water used for fracking in Webb County is much smaller than the entire county's water use because that county includes another large water user, the city of Laredo. 

Glasscock and Irion counties, also in the top 10, are in West Texas' oil-rich Permian Basin, where water recycling and the use of brackish water is likely more prevalent because of the geology in the region: When water is sent underground for fracking, a large portion of it comes back to the surface and can be reused. Despite having a population of less than 2,000, Glasscock County's overall water use is quite high even when hydraulic fracturing is not considered, because agriculture is a major water user in the county, where irrigated cotton farming dominates. 

Even in North Texas' gas-rich Barnett Shale, where drilling activity has decreased significantly in recent years due to low natural gas prices, water use for fracking is still high in Montague County. Fracking operations there in 2012 used about one-third the amount of water the entire county, with a population of about 20,000, used in 2011. 

The total water use in Texas counties in 2012, while not yet available, is likely larger overall than the 2011 numbers. That's because of more hydraulic fracturing activity and because of the population increase associated with it.