Where does our water come from? KSAT Explains

San Antonio Water System now taps into 9 different sources

SAN ANTONIO – Water may just be the new oil in Texas.

As droughts become more frequent, cities continue to sprawl, and demand rises, the value of water is forecast to increase.

With that in mind, where does the water for San Antonio, which sits on the edge of the Chihuahuan Desert, come from?

This year proved to be a test for the Alamo City, with one of the driest years on record. It put a strain on a now highly regulated aquifer. Years ago, this kind of situation might have been dire, but in a stretch that saw the Edwards Aquifer, at the J-17 well, drop to 630 feet, panic never set in.

“Very simply, it’s because we have adequate water supplies,” said Robert Puente, CEO of San Antonio Water System. ”Every single water source in this area, we’re actively using.”

How does it break down?

Fifteen different water projects are in use from nine different sources, according to SAWS. The chart below shows what San Antonio’s water sources were in 2021.

While it’s just one year, it gives us a general idea of how our water situation breaks down. Keep in mind that the recycled water portion is only for businesses and industry and not for drinking water.

You’ll also notice that the Edwards Aquifer is still our leading source of water and historically, it’s what we’ve always turned to.

2021 Water Distribution Report from San Antonio Water System (SAWS)

History of San Antonio’s water supply

”Prior to 2000, we were exclusively dependent on the Edwards Aquifer and for good reason,” said Steve Clouse, chief operating officer for SAWS. “It was such an abundant supply, and whenever San Antonio grows, you could pretty much drill a well and run a pipe, and we were there.”

When the aquifer became regulated in 1996 to protect endangered species, it forced SAWS to pivot when it comes to water supply, bringing us to where we are today.

For CEO Robert Puente, in that short time, he feels San Antonio has become the best-positioned city in the state when it comes to water.

”I don’t think its hard to quantify. We are the best,” said a confident Puente. “I don’t say that with any humility. I say it as a fact.”

”I don’t know of another city in the U.S. that has this diversified water portfolio,” added Clouse.

Underground water storage & SAWS desalination plant

Both are bold statements, but backed up by impressive facilities like the H2Oaks plant in Southern Bexar County.

”They talk about the A-B-C’s of water,” explained Puente. “Aquifer storage and recovery: we have the nation’s largest. Brackish water: we have a plant here. C: conservation: best in the nation.”

Parts of that equation are found at the H2Oaks plant, including the Aquifer Storage and Recovery program, known as ASR. It’s an underground water bubble that sits under an expanse of land and cows.

Really, it’s the Carrizo Aquifer, with some extra space. In wet years, SAWS has rights to Edwards Aquifer water that won’t get used. They can store it here, kind of like a bank. In dry years, it can be drawn up and distributed. And because it is stored underground, it doesn’t evaporate.

”In these super-duper dry years, people want to water their grass, because its so darn dry,” explained Clouse. “So we’re able to use that water that we stored during the years that it’s really wet and distribute that water for people to irrigate their grass with.”

Nearby is the desalination plant. It draws from the Wilcox Aquifer, which sits below the Carrizo. Its water is extremely salty.

”The desal water that we’re using is water that nobody else is using in the area,” said Clouse. “It’s too salty for people to use for drinking water down there. It’s too salty for the agricultural community.”

The once-unusable water flows from wells to inside the desalination plant and undergoes a transformation. Inside, massive water pumps push water through membranes to get the salt out.

While desal water only accounts for a small portion of our water supply, there is room for more membranes to increase output in the future.

Desal is poised to be one of our most resilient sources going forward. The water is treated chemically to match Edwards Aquifer water, so customers won’t be able to tell the difference.

Local Carrizo water, which is also harvested on property, goes through a similar process and is sent out through giant pumps. In all, the H2Oaks facility can produce 10 to 50 million gallons a day.

Location of SAWS H2Oaks Center and Agua Vista Station (Copyright 2022 by KSAT - All rights reserved.)

Vista Ridge: SAWS’ most ambitious project

Meantime, on the other side of Bexar County sits the Agua Vista station, serving San Antonio’s North Side.

The site is the termination of the Vista Ridge pipeline. If that sounds familiar, that’s become the 142-mile pipeline, which brings water from Milam County to San Antonio, was mired in controversy in the mid-2010s. It remains SAWS’s most controversial water source. The project took years to plan, construct, and get online.

”It’s a generational-type of project,” said Puente. “It is the largest water P3 project in the nation.”

P3 means that it involved the private sector, whom SAWS worked with to get it done. The private companies took on the risk by building the infrastructure, while SAWS just pays for and accepts the water to the tune of 45 million gallons a day.

Not everyone agrees the project was a success.

”The Vista Ridge pipeline was just a big boondoggle that was put over on the citizens of San Antonio,” claimed Alan Montemayor, chairman of the Alamo Group of the Sierra Club.

Critics like Montemayor said the cost wasn’t worth the $900 million price tag, and the idea of taking water from others is a risky proposition.

”It has saddled the citizens of San Antonio with almost $3 billion dollars in debt that we’ll be forced to pay off over the next 30 years,” claimed Montemayor.

SAWS admitted it was expensive, but it pointed out that the city council approved the rate increases to cover the cost. Those rate increases, which spanned from 2014 to 2019 are now complete.

”Even though the aquifer dropped down to the point where we were right at 630 feet, we should have been in stage 3, stage 4,” said Clouse. “The fact that we had something like Vista Ridge coming into San Antonio is why we’re allowed -- why we can say there’s no reason for us to go to stage 3 or stage 4.”

Montemayor argued that, in the end, it’s too much water. He added that he believed it was a deal cut for water-hungry big business and not the citizens of San Antonio.

“It’s the individual homeowners and ratepayers that bear the brunt of that, not necessarily the businesses in San Antonio,” added Montemayor.

”Vista Ridge -- the source is closer to Austin than it is San Antonio. We were willing to put our neck out and put our ratepayer money out there to get that water source,” said Puente, when speaking about the need to be aggressive in securing water.

The future...

Regardless of philosophy, conservation is one factor that all agree is important. San Antonians have become accustomed to doing their part.

Water restrictions are nearly a mainstay these days and drought tolerant yards are more common than ever. As stories continue to come in from places like water-starved Arizona and California, and after the drought we saw this summer, a diverse water portfolio provides a level of reassurance for the future.

”If we do have a repeat of the drought of 1950s, we are ready for it,” added Clouse.

Watch more KSAT Explains episodes here

About the Authors:

Justin Horne is a meteorologist and reporter for KSAT 12 News. When severe weather rolls through, Justin will hop in the KSAT 12 Storm Chaser to safely bring you the latest weather conditions from across South Texas. On top of delivering an accurate forecast, Justin often reports on one of his favorite topics: Texas history.

Myra Arthur is passionate about San Antonio and sharing its stories. She graduated high school in the Alamo City and always wanted to anchor and report in her hometown. Myra anchors KSAT News at 6:00 p.m. and hosts and reports for the streaming show, KSAT Explains. She joined KSAT in 2012 after anchoring and reporting in Waco and Corpus Christi.