The Barton Springs Edwards Aquifer Conservation District announced a Stage 3 Exceptional Drought on Sept. 12, according to a news release from the district.
The groundwater conservation district, which works to monitor and conserve the Edwards and Trinity aquifers, is set to implement the groundwater drought on Oct. 1. Around 55% of the state’s water supply comes from groundwater sources, according to the Texas Water Development Board.
“It’s such an essential resource for millions of Texans,” said Shay Hlavaty, communications and outreach manager at the Barton Springs Edwards Aquifer Conservation District.
A Stage 3 exceptional drought impacts cities that have permits to pump wells and the flow at Barton Springs. The groundwater conservation district manages over 120 permit holders, including cities like Buda, that are allowed to pump from the aquifer. When a Stage 3 drought is declared, permit holders are required to reduce their pumping by 30-100%, according to the news release.
Hlavaty said a groundwater drought is different from a meteorological drought, which looks at rainfall and soil moisture. She said a groundwater drought takes into account water levels underground.
Hlavaty said each of the 98 groundwater conservation districts in Texas has their own standards for what is considered a drought. The Barton Springs Edwards Aquifer Conservation District has two drought indicators: the flow at Barton Springs and groundwater levels at the Lovelady monitor well, Hlavaty said. If either indicator location falls below a certain level, the district declares a groundwater drought. Hlavaty said both indicators need to be above the threshold to exit drought.
The Edwards Aquifer is made of limestone, which has small fractures and pores that hold water, similar to a sponge, said Brian Hunt, a hydrogeologist at the Bureau of Economic Geology at UT. When water levels drop because of drought or pumping wells, the aquifer can recharge, Hunt said.
“It’s a renewable system,” Hunt said. “That’s what’s unique about the Barton Springs aquifers.”
The aquifer recharges when water runs through drains in creeks and when it slowly sinks into the ground, said Jeffery Watson, senior hydrogeologist at the Barton Springs Edwards Aquifer Conservation District.
“If you walk around in Onion Creek when it’s flooding, there’s actually places where you can see whirlpools form where water is going right into the aquifer,” Watson said.
Watson said the time it takes to replenish the aquifer depends on the amount of rainfall and the distribution of rainfall.
The average rainfall for Austin is about 35.5 inches a year, according to the National Weather Service Austin Climate Summary Report. Watson said there is currently a rainfall deficit of 30 inches, or around a year’s worth of rain.
Additionally, the rainfall needs to sustain a constant flow in the creeks to alleviate groundwater drought conditions, Hunt said.
“You can have a whole lot of rain at once, but it really doesn’t generate creek flow,” Hunt said. “It all just floods and dries up, and it’s really hot. We don’t have sustained recharge occurring.”
Although the groundwater drought will mainly impact permit holders who pump wells from the aquifer, visitors at Barton Springs pool will notice the flow is lower than usual. However, people can still swim in the pool.
“It’s a recreational spot, it’s an environmentally sensitive spot,” Hunt said. “There’s endangered species there, and it’s just the icon of Austin.”
Editor’s Note: A previous verison of this article included the headline “Barton Springs Edwards Aquifer Conservation District announces groundwater drought for second time in history” this is not accurate. The district annouced an exceptional drought for the second time in history.
