SBCA EXPLAINER:
Barton Springs Drought Plan
The Barton Springs Edwards Aquifer Conservation District (BSEACD) is responsible for the water that supplies both thousands of residents and Barton Springs. In this article, Craig Smith — a former BSEACD director and a current SBCA board member — explains how the district developed its drought management plan.
The crown jewel of Barton Creek and all of Austin is Barton Springs — the third-most bountiful spring in Texas, the habitat of two endangered species of salamanders, and a beloved swimming hole for thousands of human visitors each year. The springs are recharged by rain that falls in the watersheds of six local creeks (Barton, Williamson, Slaughter, Bear, Little Bear, and Onion), as well as the Blanco River. Much of the water in these streams seeps into the porous limestone formation of the massive Edwards Aquifer that lies under parts of Austin, San Marcos, New Braunfels, and San Antonio. The northern portion of this underground formation is formally known as the Barton Springs Segment of the Edwards Aquifer.
The Barton Springs aquifer is also the primary or sole source of water for more than 60,000 residents and businesses in Rollingwood, Sunset Valley, Buda, Kyle, Creedmoor, and other communities. Water that’s withdrawn from wells in the aquifer to serve these communities is water that’s not available for the swimmers and salamanders at Barton Springs. In an area such as ours that’s prone to drought — increasingly so with climate change — this competition for limited water is a recurring problem that requires reasonable regulation to satisfy all the needs.
It is the job of the Barton Springs Edwards Aquifer Conservation District to balance these competing demands for water. Created by the Texas Legislature in 1987, BSEACD covers most of the Barton Springs aquifer’s Recharge Zone, as well as the communities served by wells in the aquifer. Like all Groundwater Conservation Districts (GCDs) in the state, BSEACD has authority under Chapter 36 of the Texas Water Code to issue permits and regulations for water wells within its boundaries.
BSEACD initially allowed existing wells — mainly larger wells providing public water supply, as well as exempt wells with limited capacity on tracts bigger than 10 acres — to keep pumping their existing volumes of water out of the aquifer. In 2004, the district completed a “sustainable yield” study to evaluate the effects of pumping on groundwater availability and spring-flow during a potential return of drought-of-record conditions similar to the 1950s, when the Barton Springs aquifer reached its lowest-recorded level. The study showed that wells in BSEACD had already reached their sustainable yield limit. Without some curtailment, already-permitted pumping during severe drought conditions would cause Barton Springs to stop flowing entirely, and would impair the volume that could be pumped from almost 20 percent of existing wells. Such an outcome was unacceptable.
Based on the sustainable yield study, the wells that were permitted prior to September 9, 2004 were designated by BSEACD with “Historical Use” status. That means that their pumping can be limited but not totally curtailed, even in a severe drought, because communities and individuals depend on them. Permits issued after September 9, 2004, are “Conditional.” They’re only fully effective when the district isn’t in a drought, but are subject to volume reduction when it is — and if necessary, total curtailment.
Even Historical permits are subject to reduction when the aquifer is in drought condition, as measured by two indicators — water flow at Barton Springs, estimated from the level in a well just above the main spring outlet, and the level in the Lovelady monitor well located near South First Street and Stassney Boulevard in Austin, which has a long history of recorded measurements. BSEACD requires every permittee to file a User Drought Contingency Plan (UDCP) describing how it will comply with prescribed reductions in event of drought. The district requires greater pumping reductions as water levels in the aquifer decline: 10% (voluntary) in a water conservation period, 20% (mandatory) in Alarm Stage drought, 30% in Critical Stage drought (the current stage), and 40% in Exceptional Stage drought. A final reduction by 50% of permitted volume, which would cause serious hardship, would take effect if the district declares an Emergency Response Period.
In 2004, BSEACD also worked on a project to develop a Habitat Conservation Plan (HCP) for two species of salamanders found only in Barton Springs and its aquifer, and nowhere else — the Barton Springs salamander and the Austin blind salamander. Although the district’s legal obligation to protect these endangered creatures was uncertain, it committed to managing groundwater production to avoid or minimize impact to the salamanders as much as possible. The district tried to do that while also protecting the rights of groundwater owners.
Studies of dissolved oxygen concentration and salamander mortality showed that in extreme drought, the flow for Barton Springs needed to be higher than could be achieved under BSEACD’s existing permitting and drought management program. This finding led to a recommendation that the Desired Future Condition for the Barton Springs aquifer in a severe drought should be no less than 6.5 cubic feet per second (CFS) of spring-flow. This minimum spring-flow, while even lower than the lowest flow in the record drought of the 1950s, would allow the salamanders to continue to survive, as they did then. But, it’s a volume that would leave only 5.2 CFS for human consumption. (The Desired Future Condition is the target water level for the end of the 50-year planning period that was established in House Bill 1763, passed by the Legislature in 2005.)
BSEACD realized that under its existing rules and permits, it would not be able to achieve that goal if a severe drought returned. This prompted a new focus on water conservation and demand management, including the encouragement of alternative water supplies to substitute for pumping water out of the Edwards Aquifer. Potential alternative water sources include surface water, the Trinity Aquifer that lies beneath the Edwards, and the brackish water in the Edwards Aquifer east of the “bad water line.” Supplies could also be extended through aquifer storage and recovery (ASR) facilities, in which surplus water in non-drought times is injected into a deeper aquifer such as the Trinity, from which it can be withdrawn when needed during drought. One of the district’s permittees is currently using ASR to extend its water supplies, and others are investing in ASR infrastructure. When alternative supplies are secured, firm-yield Edwards production that is retired is put permanently into an Ecological Flow Reserve and may not be re-permitted for firm-yield production. So far, 0.35 cfs of permitted production has been retired and put into the reserve.
BSEACD’s Habitat Conservation Plan was approved by the U.S. Fish & Wildlife Service in 2018, and the district was issued a 20-year incidental take permit, protecting it from liability for the unavoidable loss of some salamanders during drought. During the decade that the HCP was being developed, the conservation measures intended to minimize the impacts of groundwater production on the endangered species became integrated into the district’s management scheme and regulatory program. Currently, the district’s Management Plan is aligned with the HCP in all material respects.
The Barton Springs Edwards Aquifer Conservation District aims to limit total groundwater production from the freshwater Edwards Aquifer (including from exempt wells, to no more than 5.2 cfs during severe drought conditions), which is consistent with the objectives of the HCP and the Desired Future Condition. Achieving that aim would satisfy the water needs of both humans and wildlife.
This article is based on and borrows liberally from the Management Plan of the Barton Springs Edwards Aquifer Conservation District adopted on October 13, 2022.
For more information, please contact Brian Zabcik, SBCA Advocacy Director, at brian@savebartoncreek.org