Global warming likely to mean more droughts and more floods

Despite threatened shortages, the Edwards Aquifer Authority successfully lobbied the Legislature last session to raise the aquifer's pumping limit by 27 percent, from 450,000 acre-feet a year to 572,000 acre-feet a year.

When presented with the dichotomy of less water and more pumping, Robert Potts, who was the authority's general manager at the time, said it's the authority's job to administer water permits and the state's job to do the water-supply planning.

Potts said the authority orders limits during droughts. And those drought restrictions were strengthened at the same time the cap was lifted.

This has a significant effect, Potts said. For example, even under current recharge conditions, Comal and San Marcos Springs would be dry 81 percent of the time if maximum pumping were allowed.

"We've kept it from getting any worse," Potts said. "I don't think that's something people understand."

Growing thirst

The various models used to predict climate are clear on one thing: South Texas is going to get hotter.

The United Nations Intergovernmental Panel on Climate Change in February reported that global temperatures will most likely increase 3 to 7 degrees by the end of the century.

Texas temperatures, according to the IPCC, will rise as much as 3 degrees as early as 2020. The South Texas average will rise by up to 9 degrees by the end of the century, said Claudia Tebaldi, a project scientist at the National Center for Atmospheric Research.