At Olmos Park City Hall this week, council members discussed whether to adopt regulations that would affect residents wanting to tap into the groundwater below their property to water their lawns and gardens.

The debate followed an uptick in well drilling this year among residents of the urban enclave of 2,200 roughly 2 miles north of downtown San Antonio.

Some Olmos Park residents and councilmembers blame the San Antonio Water System, which provides water service to Olmos Park. SAWS rates have risen every year for the past decade, and the utility tries to motivate customers to conserve by charging for water at a progressively higher price as a customer uses more per month.

Rather than pay high bills – or use less SAWS water – several Olmos Park residents found another path: hiring a drilling contractor to bore a private well for irrigation purposes. While SAWS customers within San Antonio city limits are barred by ordinance from doing so, Olmos Park residents are not.

“That’s the beauty of being in a small municipality – we’re not in the City of San Antonio,” said Olmos Park Councilwoman Erin Harrison, who said she doesn’t have a well but was “strongly considering it.”

However, a San Antonio Report review of water well records and local ordinances shows that private well drilling is more prevalent in some suburbs than others. Olmos Park is one of seven municipalities in Bexar County that don’t regulate the practice.

Like most of Bexar County, Olmos Park receives 100 percent of its water service from SAWS. SAWS President and CEO Robert Puente described the trend as “a movement in Olmos Park to drill wells and get out from having to pay these water bills.”

“And these water bills are huge because they use a huge amount of water,” Puente said at an Oct. 14 panel discussion hosted by the San Antonio Hispanic Chamber of Commerce. “It’s not because our rates are so high.”

Some residents have said their monthly water bills top $1,500. According to SAWS’ bill calculator, they would have to use more than 100,000 gallons of water in a month to earn such charges. SAWS’ average residential customer uses less than 7,000 gallons per month.

Still, some Olmos Park residents have bitter feelings toward the utility. Olmos Park Councilman Kenyon McDonald said at the Oct. 21 meeting that “his trust of SAWS is almost at zero at this point.”

“I have no doubt that this gets their attention,” Olmos Park Mayor Ronald Hornberger said of SAWS’ reaction to the drilling. “Do I care? No. … If you’re going to charge someone $1,500 per month, they’re going to find a way to lower that water bill.”

‘They’re not regulated’

Drilling a water well isn’t cheap, with costs running into the tens of thousands of dollars. Those who drill into the Edwards Aquifer must also obtain permits and either rights to pump water or exemptions for domestic wells from the Edwards Aquifer Authority, which regulates groundwater pumping. The vast limestone water-bearing Edwards Aquifer is the main drinking water supply for the San Antonio region.

However, other shallower, less well-known aquifers have no such regulations in much of Bexar County. Olmos Park property owners can legally use as much non-Edwards groundwater as they can pump – for free.

The thing is, the water in the shallow aquifers below Olmos Park still likely originates in the Edwards Aquifer, according to John Hoyt, a geologist who formerly served as assistant general manager of the Edwards Aquifer Authority. Fractures in the geology below Olmos Park allow water to flow up from the Edwards, which also feeds the nearby Blue Hole and other springs at the headwaters of the San Antonio River.

“There [are] so many fractures that almost any well that they drill over there will intersect some of those fractures that produce water from a direct connection with the Edwards, so it makes a pretty good well,” Hoyt said. “So they can water their estate all they want. They’re getting Edwards water, but they’re not regulated.”

At the Oct. 21 Olmos Park City Council meeting, several residents interested in drilling their own wells spoke of their private property rights to the water below their land, a doctrine longstanding in Texas known as the rule of capture. They also touted the benefits of diverting their use away from public water supplies.

“I feel like I’m doing something very responsible civically as well as environmentally,” resident John Hogg told council members. “We’re actually saving water.”

Some Olmos Park well owners seem to believe the Edwards doesn’t intermingle with other aquifers.

“The two rivers do not run together; they’re separated,” claimed resident and private well owner David Garza.

Olmos Park City Council doesn’t seem to want to stand in the way of residents wanting to drill. After viewing seven pages of proposed water regulations that would have created a municipal well registry and imposed some standards on drilling contractors doing the work in city limits, council members sent the draft back to City staff, asking for a rewrite.

Though some council members wanted to scrap the ordinance entirely, Hornberger said Olmos Park officials have some interest in knowing where wells are located so they can be sure they’re properly plugged when no longer in use.

“If you don’t put some kind of system in place, we’ll never find out how many wells we have,” Hornberger said.

Olmos Park sits north of downtown San Antonio near U.S. Highway 281. Credit: Scott Ball / San Antonio Report

‘Greenest lawns in the metro area’

The Texas Water Development Board posts extensive information about water wells on its website. According to its database of well reports, Olmos Park is far from the only municipality in Bexar County where residents have opted to drill their own wells for domestic use or irrigation.

A San Antonio Report review of ordinances for all municipalities in Bexar County also reveals a hodgepodge of regulations, with many having no local measures to address private wells at all.

Most of the 1,590 wells labeled “domestic” and 108 wells labeled “irrigation” tend to occur in concentrated areas in the northwestern half of Bexar County, roughly matching the boundaries of limestone aquifers, including the Edwards.

Records show that Olmos Park has 13 private wells, six of them drilled in 2020. But the true epicenter of private well drilling in San Antonio’s inner suburbs is Terrell Hills.

Terrell Hills, which has a population of 5,400, has 26 private wells, most of them less than 10 years old, well reports show. Like Olmos Park, Terrell Hills residents receive water service from SAWS and have no restrictions on well drilling in city limits.

Similarly, Castle Hills, Converse, Helotes, and Windcrest also do not address private wells in their city codes. Selma’s ordinances include a provision that simply prohibits mixing private well water with municipal water.

By contrast, cities such as Shavano Park and Leon Valley have ordinances more similar to San Antonio’s. The San Antonio Report reviewed well records from the Texas Water Development Board and could not find any private water wells currently in use in either city.

Melinda Moritz, Leon Valley’s public works director, told the San Antonio Report that she can’t recall anyone applying to drill a private well in the 30 years she’s worked for the city.

“The only reason that we would is if someone wasn’t close to our water system,” Moritz said. Leon Valley operates its own public water system with two supply wells that tap into the Edwards Aquifer, though a quarter of the city receives SAWS service.

She wasn’t surprised to hear about the recent water well drilling in Olmos Park.

“They’ve got the greenest lawns in the whole metro area,” Moritz said.

Moritz acknowledged that public water utilities have an incentive to keep customers dependent on their services. But she described how Leon Valley has also embraced the water conservation ethic prevalent among much of San Antonio.

“We give rebates for low-flow toilets, rebates for high-efficiency washing machines, rebates for xeriscaping, rebates for putting in rain barrels,” Mortiz said. “We talk about conservation all the time here.”

Brendan Gibbons

Brendan Gibbons

Brendan Gibbons is the San Antonio Report's environment and energy reporter.