PLEASANTON — Envoys from the San Antonio Water System entered a proverbial lions’ den Monday to explain, to local aquifer-district officials and worried patrons, SAWS’ possible pumping of the Carrizo Aquifer in southern Bexar County as “insurance” against future drought.At the end of the special meeting of the Evergreen Underground Water Conservation District, the two sides agreed to talk more — quarterly meetings — and share technical data about the Carrizo Aquifer. The Evergreen board took no formal action during the two-hour meeting. Board President Ken Stephens presided. Two SAWS engineers, Susan Butler and Mike Brinkmann, said SAWS wants to be a “good neighbor” with Wilson and Atascosa counties. But they acknowledged that consultants’ computer modeling so far cannot fully predict the pumping’s “draw down” (lowering) effect on nearby wells in Wilson and Atascosa counties.

“Is a two-foot draw down a mile out acceptable?” added Butler, SAWS’ supply-development manager. “We don’t know.” More study is needed, she said. While SAWS’ aquifer storage and recovery (ASR) project is in advanced testing in southern Bexar from 2004 to 2007, the engineers explained, the city might need up to 30,000 acre-feet a year from the Carrizo to help meet peak demands in dry spells before other water sources are developed. An acre-foot is about 325,860 gallons. There is no ground-water district in the extreme south of Bexar County.

“We’re not going to be pumping in the long haul; this [ASR] is a storage project,” Butler said. Brinkmann, an ASR project engineer, added that SAWS’ goal is to “maximize the use of the Edwards water” it has permit to, by storing surplus underground in ASR. However, Butler and Brinkmann could not guarantee that SAWS’ board — which includes representatives of San Antonio’s city council — might not decide later to pump the Carrizo’s confined portion for a longer period. “I can’t tell you there’ll never be another [Carrizo water] drop produced” there after 2007, she said during persistent questioning by regional water planner and Floresville-area resident Darrell Brownlow.

Fearing harm to shallow Carrizo wells in Wilson and Atascosa counties, the Evergreen’s board remained politely hostile Monday to the idea of Carrizo pumping by SAWS. So were many of the two dozen spectators. They included area farmers and representatives of Wilson and Atascosa counties’ governments and three rural water-supply corporations: Three Oaks, Picosa, and Oak Hills. Members of the Wilson County Water Action Project attended, too. Butler and Brinkmann could not answer another question: Would heavy pumping of Carrizo water in southern Bexar County ease pressure on shallow formations of oil, allowing its movement into aquifers? “I guess what it all boils down to [is], we don’t trust you,” Evergreen board member William Ruple told the SAWS representatives at one point.

The last time Butler and Brinkmann visited the Evergreen’s board was more than a year earlier. The topic then: SAWS’ ASR plan to eventually inject, in wet-season plenty, Edwards Aquifer water in the small confined portion of the Carrizo Aquifer in extreme southern Bexar — and possibly expand it later to the immediate south in the Evergreen district. (SAWS will need a permit from the Texas Natural Resource Conservation Commission to inject water into the aquifer.) The Evergreen district comprises Wilson, Atascosa, Karnes, and Frio counties.

Any spirit of rural-urban cooperation had suffered severely since then, though. Evergreen officials were jolted last month by a San Antonio news report that outlined SAWS’ plan to also pump the Carrizo on its approximately 3,200 acres that are the site of the ASR project. Butler said she regretted SAWS had not been in regular contact with the Evergreen’s board and staff before the article came out. “There’s no excuse for not being in touch in the last year,” she said. “No excuse.”