After Alcoa pumping, drought no problem

POSGCD survey shows major aquifer holding up during record dry
Reporter Editor

Joseph Montelongo, City of Rockdale water supervisor, checks out Texas Street well, one of eight in POSGCD summer survey. 
Reporter/Mike Brown Joseph Montelongo, City of Rockdale water supervisor, checks out Texas Street well, one of eight in POSGCD summer survey. Reporter/Mike Brown Concern over the record-breaking drought led the Post Oak Savannah Groundwater Conservation District (POSGCD) to survey eight water wells in the Rockdale area this summer and the results have basically confirmed the strength of the area’s premier “underground lake.”

“The Simsboro Aquifer is a prolific producer,” Gary Westbrook, POSGCD general manager said.

Five of the wells measured are in the Simsboro (first five in adjoining table). They show the water table has lowered only between one and 12 feet from winter 2011 to this summer.

But there’s a much bigger historic picture where the Rockdale area is concerned.

“ This drought has really been nothing, for effect on underground water, compared to the amounts Alcoa was taking out of the Simsboro for decades,” Westbrook said.

BIG PUMPS—Until the last few years, Alcoa was pumping massive amounts of water to “depressurize” lignite at Sandow.

“They are still pumping about 7,000 acre/feet per year,” Westbrook said. “But four years ago that figure was 15,000 and four years before that it was 30,000.”

Data in the new survey doesn’t go back that far.

SE A SONA L—Westbrook said water depths usually aren’t measured in the summer at all.

“ That really doesn’t give a true representation of the condition or capability of an aquifer,” he said. “Summer is the peak use time for wells, with people watering and lots of demand. You really want to measure in the winter, because that gives the aquifer a chance to recover when water levels across the District are more stable.

“In other words, we picked a couple of wells which reflect the impacts of nearby pumping wells and several which are removed from the active wells. The wells nearest the production areas reflect the most drawdown, with the wells farther away reflecting very little change.

“ In w inter months we w ill see all of the dramatic impacts reduced and the water levels will be more uniform across the District as the aquifer recovers.”

But the POSGCD took some representative summer readings to try and get a handle on how the ongoing drought has affected aquifers.

CITY WELL—The well which has shown the most change in the past two years has been the City of Rockdale’s Texas Street well, which is not in the Simsboro. It’s in the Hooper, a different aquifer below the Simsboro formation.

That level has dropped 33 feet since the winter 2010 reading.

Howe ver, probably showing how long-term the current drought has actually been, most of that drop (25 feet) had already occurred by the winter 2011 reading. The drop between last winter and the summer reading was only eight feet.

And Rockdale isn’t having production problems, even with 70 days of 100-degree-plus temperatures this spring and summer.

“ We’re keeping up with the demand,” Joseph Montelongo, city water supervisor, said.

The final two wells on the front-page box draw from the shallower Carrizo and Yegua- Jackson aquifers. Their water levels were virtually unchanged since the winter 2011 reading.

‘PROLIFIC’— Westbrook has used the word “prolific” to describe the Simsboro.

“I want to be sure everybody understands that when I talk about what a strong aquifer the Simsboso is, I’m certainly not saying that the District is not concerned for it in the future and that the District does not believe it needs to be protected,” Westbrook said.

“The District is very concerned about protecting it, and thanks to the work of our directors we have rules and a management plan in place to do just that” he said. “I’m just stating a fact. This is a prolific aquifer and when we finally do get those inevitable rains it’s going to recharge quickly.”

Westbrook said anyone with concerns about their wells can call the POSGCD at 455-9900 or, toll-free, 1-800-231-8196.

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