Darell T. Brownlow, Ph.D, has published an article giving his analysis and opinion of the ability of the Carrizo Aquifer to supply water demands caused by fracing of wells in the Eagle Ford play. The article was published in the newsletter of the Texas Ground Water Association, Fountainhead, and can be found here: Brownlow Article.pdf
Dr. Brownlow, a hydrologist, concludes that there is plenty of water in the Carrizo, in most places, to meet the demands for frac water. His estimates:
- There are about 6 million acres in the Eagle Ford play, and a possible 20,000 oil and gas wells (one well per 300 acres).
- An average frac job uses 15 acre-feet of water (4,887,765 gallons, or 115,375.5 42-gallon barrels).
- So, the frac jobs on those 20,000 wells would use about 300,000 acre-feet of water over the life of the play.
- Current withdrawals from the Carrizo Aquifer are about 275,000 acre-feet per year; so the entire demand for frac water from Eagle Ford wells would equal about one year’s withdrawal of water from the aquifer. At a rate of withdrawal of 275,000 acre-feet per year, groundwater management studies estimate that the Carrizo water table will drop an average of 30 to 35 feet by 2060.
Dr. Brownlow says that, if a successful Eagle Ford well makes 300,000 to 400,000 barrels of oil at $80/bbl, the return to the landowner would be $520,000 per acre-foot ($1.60 per gallon). In contrast, the return to a farmer using the same acre-foot of water to irrigate corn, peanuts or coastal hay would be $500 to $1,000 per acre, or about $250 per acre-foot of irrigation water. “The point here is that using groundwater from the Carrizo for hydraulic fracturing in the Eagle Ford Shale has enormous economic potential for landowners, oil production companies and the entire region. Moreover, from a geologic and water planning perspective, additional impact on the aquifer appears minimal.”
Dr. Brownlow is a resident of Wilson County, a cattle rancher in LaSalle County, serves on the South Central Texas Regional Water Planning Group (Region L), and was the governor’s appointee to the Evergreen Underground Water Conservation District from 2000-2010.