HAYS COUNTY, Texas (KXAN) — A population boom in the Texas Hill Country and a growing demand for housing could drive water supplies towards a “tipping point,” according to Katherine Romans with Hill Country Alliance.

“In the 1950s, our drought of record in Texas, we had about 800,000 people in the Texas Hill Country. Today, that number is closer to 3 million,” Romans said about the growth.

“Inevitably, those folks are are bringing more demand for water resources.” According to the Hays Trinity Groundwater Conservation District, wells in the northern section of the Middle Trinity aquifer have dropped 12 feet since 2020.

According to hydrologist Doug Wierman with Texas State University’s Meadows Center, groundwater wells in the area are at the lowest he’s ever seen.

“With the explosive growth, the wells right now and wells that are monitored by the groundwater district, they’re at the lowest point that I’ve ever seen.”

Doug Wierman, hydrologist

Wierman served on the Hays Trinity Groundwater Conservation board from 2004 to 2010. Groundwater conservation districts are the group responsible for monitoring groundwater wells.

Developers draining aquifers

Wierman said developers can be permitted to draw as much water as they want, but they must be able to justify the use. “They have to show the water is available through [an] aquifer pump tests,” Wierman said.

According to HTGCD, permits “over 651,702 gallons per year” require a well performance test to be done. “Permit applications over 1,955,106 gallons per year” must perform an aquifer test.

The Pedernales River helps feed the Middle Trinity Aquifer many developers rely on. It is currently dried up. (Eric Henrikson/KXAN)
The Pedernales River helps feed the Middle Trinity Aquifer many developers rely on. It is currently dried up. (Eric Henrikson/KXAN)

To perform aquifer pump tests, a “test well” is drilled and then pumps water for 24 to 48 hours. As the water level in the well goes down, geologists and hydrologists must then test the impact the well is having on the surrounding spring shed.

Over 250 wells and 1,000 utility connections have been registered in the Hill Country since 2020, HTGCD said. Some of the wells, the district said, have had to drill deeper to the Lower Trinity Aquifer, which is located beneath the Middle Trinity.

Recharging and refilling aquifers — a Texas-wide issue

One of the major issues, according to Wierman, with new developments is they limit the ability of aquifers to recharge.

“If you’re covering up the aquifer surface with roads and rooftops, you’re taking away that area for infiltration.”

Each aquifer refills differently. “The Edwards Aquifer is very karstic, very porous. It fills up quickly. The Trinity aquifer is slower,” Wierman said.

The Ogallala up in the panhandle, it basically doesn’t recharge. And they’re pumping water, and they’re just basically going to pump it dry.”

According to HTGCD, the Lower Trinity Aquifer “has no immediate recharge capability.”

Romans said she worries many developers may not understand how these aquifers work. This is a special concern for her with developers that have not built in Central Texas where extreme droughts and flooding are common.

When asked if the Hill Country is reaching a “point of no return”, Romans said “Absolutely. I wake up in the middle of the night worrying about the Hill Country increasingly inching towards that tipping point where our demand for water resources has outpaced the ability of our aquifers and rivers to replenish themselves.”