Balancing water needs of aquifer's many users

Water restrictions put in place during this year's drought are nothing compared with those of the future if management of the Edwards Aquifer is not changed, scientists say in a new report.

In a worst-case scenario, pumping from the aquifer would have to be cut by as much as 97 percent during a drought to ensure the survival of endangered species dependent on flows of the Comal and San Marcos springs.

“This is where the science has led us to,” said hydrologist Robert Mace, who oversaw research for the report. “This is the start of the process, not the end.”

The findings, presented to the Edwards Aquifer Recovery Implementation Program steering committee last week, quantify the problem of meeting the region's water needs during a drought.

The committee must produce a plan that would balance the needs of the 2 million people who depend on the aquifer with the endangered species and downstream communities that need the springs to keep flowing for their own water use.

The 26 stakeholders on the RIP committee include the Edwards Aquifer Authority and representatives of cities, farmers, Dow Chemical, environmental groups, and state and federal agencies from Central Texas to the Gulf Coast. The committee has until 2012 to come up with a plan that the U.S. Fish and Wildlife Service and the EAA will approve. Without a plan, the aquifer could come under federal government management.

Cutting pumping from the aquifer by 97 percent is not considered a workable solution by even some of the committee's most conservation-minded members. Instead, the number is a catalyst for the group to re-evaluate how the aquifer could be better used.

It is a starting point for the negotiations among the stakeholders about possible changes to the management of the aquifer, RIP manager Robert Gulley said.

“It's the first time we have had all the stakeholders at the table and they appear to be talking,” he said.

Options include pumps to recirculate water, dams and changes to how and when pumps are used.

There are also options to improve the habitat near the springs for the endangered species and protect them from parasites, non-native species and the public.

Some of this work has already been done, but much more will be needed to allow more pumping from the aquifer during a drought. That will be a driving force at three retreats the group has scheduled for this winter.

The group was created in 2007 by state law, which also required the study, done by the RIP's science subcommittee of hydrologists and biologists.

That legislation was the result of a 1991 federal lawsuit by the Sierra Club, backed by financial interests of those downstream, to protect endangered wild rice, fish, salamanders, beetles and amphipods that live in or near the Comal and San Marcos springs.

Out of the lawsuit, the state created the aquifer authority to allocate withdrawals from the aquifer. The problem of protecting endangered species was not solved.

The RIP study will form the scientific basis for management of the aquifer while protecting the species. It looks ahead at what could happen if nothing about the aquifer and springs have changed, all users are allowed to pump their maximum amount and a severe drought occurs. That maximum is 572,000 acre-feet a year, an amount that has never been pumped. By comparison, 428,000 acre-feet were pumped in 2008.

Under that scenario, the 97 percent reduction in pumping would be required to ensure that the springs would have sufficient flow. Because it is never known when a drought as severe as the one of the 1950s will occur, the pumping reductions would have to be put in place at the beginning of almost any dry spell, said Mace, the hydrologist.

The study is the first to take a comprehensive look at the relationships between the biological demands of the springs and the pumping rates from the aquifer.

“This is a big day for us,” steering committee chairman Con Mims said. “Now our job is going to become much more serious.”

By Colin McDonald - Express-News