A Report by the Barton Springs/Edwards Aquifer Conservation District
The rains that returned to Central Texas in the fall of 2009 continued intermittently through most of 2010, ending the most serious drought to grip the Barton Springs Aquifer since the creation of the Barton Springs Edwards Aquifer Conservation District in 1987. The District regulates the pumping of groundwater from the Aquifer, which is the drinking water source for more than 50,000 people, a critical resource for many industries and employers, and the origin of Barton Springs and its ecosystem.
With the drought as a prelude, the District undertook to carry out the assignment to determine the “desired future conditions” (DFC) of the Aquifer during the next 50 years. Based on the DFC’s adopted by the groundwater conservation districts in each groundwater management area across Texas, the Texas Water Development Board will issue the amount of “managed available groundwater” (MAG) that each district may permit for withdrawal. The MAG will be, in effect, a cap on nonexempt pumping (and maybe also a floor.)
The DFC is intended to be a realistic target for groundwater conditions 50 years from now. But the MAG amount will be issued within one year after the submission of the DFC. So the DFC must be calibrated with an eye on both near-term outcomes and long-term goals. That is, the desired condition must be achievable once the MAG is issued and also achievable and still desirable in 50 years.
The staff of the Barton Springs Aquifer District, under the leadership of General Manager Kirk Holland, proposed two levels of DFC for the Barton Springs Aquifer: an upper or “all conditions” DFC to set a limit on pumping even when the Aquifer is full, and a lower or “extreme drought” DFC to define the water level to be maintained in case of a return of a great drought like that of the 1950’s. Permits for the amount of groundwater between those two levels would be available only on a conditional basis, subject to reduction and even total curtailment during drought.
In setting the “all conditions” DFC, the District’s board considered the ability of the Aquifer to supply regional water needs during times of abundance, the opportunity to implement aquifer storage and retrieval (ASR) projects during high-flow periods to increase the amount of water in storage, the ability of conditional permittees to curtail their usage through conservation and substitution of other water supplies, and the desire to avoid unreasonable acceleration of mandatory water conservation by historic permittees. After considering these factors, the Board concluded that the upper or “all conditions” DFC should be defined as maintaining an average springflow of no less than 49.7 cubic feet per second (cfs) over a running seven-year period, which corresponds to an average of 16 cfs of total withdrawals by all users, including exempt users. In other words, a pumping cap of 16 cfs per year, under any and all conditions.
Under low-flow conditions, there is an approximately one-to-one relationship between the amount of water pumped by wells and the amount of springflow. That is, each measure of water that is withdrawn results in an equal reduction in springflow. The District board considered these factors in setting the lower or “extreme drought” DFC: the vulnerability of some existing wells to depletion at low water levels; the potential for harm or even extinction to the endangered Barton Springs salamanders and other wildlife species due to low springflow, the recreational needs of the more than 500,000 annual visitors to Barton Springs Pool, the ability and costs of public water supplies and other permittees to reduce their usage and secure alternative sources in order to meet mandatory reductions, and the economic impact of those reduction on aquifer users, communities, and individual property rights. The Board concluded that the lower or “extreme drought” DFC should be defined as Barton Springs flow averaging no less than 6.5 cubic feet per second (cfs) on a monthly basis during a recurrence of extreme drought.
While springflow at that level would be lower than any ever measured at Barton Springs, it was the most that the District staff believed could be maintained under those conditions, given the much greater demand on the Aquifer now than existed during the 1950’s. The board recognized that the limits on water use would cause inconvenience and increased costs to some users and would not eliminate, only substantially reduce, the drought risk to the endangered wildlife that depends on the flow of the Springs. But the board concluded that the DFC’s fairly balanced the inconvenience, losses, and risks with the obligation of the District to conserve the Aquifer so that it can be passed undiminished to future generations.
CITY OF KYLE PERMIT APPEAL
The ability of the Barton Springs Aquifer District to limit the volume of groundwater pumping permits came under its most serious challenge during 2010, and the outcome is still to be seen. The City of Kyle requested an amendment of its permit to increase the amount of its groundwater withdrawals by 185 million gallons a year, to a total of 350 million gallons annually. Because the new permit would be a Class B conditional permit, Kyle was required, in addition to the other permit requirements, to demonstrate that it had an alternative water source and the ability to replace the permitted water if the permit were curtailed during drought.
During a three-day contested case hearing in December 2009, Kyle showed that its application met nearly all of the requirements. But the evidence showed that the City had the ability to replace only part of the requested increase in pumping. So when the District Board made its decision on February 11, 2010, it granted an increase of only the amount that Kyle showed it could replace: 100,700,000 gallons a year.
Although this increase was more than half of what Kyle had requested, the City demanded a rehearing. And when a rehearing was denied, the City filed suit against the District in a Hays County court. The suit contends that the District did not follow its own Rules in not allowing the full amount of the increase. The SOS Alliance, which participated in the contested hearing in opposition to the increase, has intervened in the suit in defense of the District’s decision. The outcome will not be known until next year, or perhaps later.
DESALINATION
The District is trying to expand the water supply options for Travis and Hays Counties by investigating a potential new water source, never previously utilized. It is the saline portion of the Barton Springs Aquifer, down-slope and generally east of the freshwater portion. The groundwater in this “bad water zone” is confined and cannot discharge at Barton Springs. So it has built up a high level of dissolved salts and other minerals over the eons and is too brackish for human and most agricultural uses.
In partnership with Texas Disposal Systems (TDS), which owns a large tract of land over the “bad water zone,” and Texas State University, the Aquifer District has applied for a series of grants to study the feasibility of tapping the saline water and making it usable through desalination in a plant powered by landfill methane gas and other waste-derived biomass fuels.
It is a long-range project and one that certainly faces an array of technical obstacles. So far, the funds for the feasibility study have not yet been found. But the District is continuing to explore this exciting possibility of combining two useless things, brackish water and landfill waste, to produce drinkable water, which is one of the most valuable things in Central Texas and the entire world.