As much of San Antonio's aged water infrastructure reaches the end of its useful life and droughts become more regular, leaks and water main breaks for the San Antonio Water System have become more common.

Last week, SAWS' board of trustees approved an updated water conservation plan that makes preventing water loss a priority for SAWS over the next five years. SAWS experienced its greatest amount of annual water loss ever last year — at more than 21 billion gallons, due to an unusually high amount of main breaks exacerbated by the extreme heat and drought conditions.

“We fixed 7,400 leaks last year,” said Carlos Mendoza, SAWS distribution and collection operations manager. “The year before that, about 6,400 leaks.”

When a pipe breaks on the customer's side of the water system, it's the customer's responsibility to fix the leak privately, using a contractor or plumber that they hire. But if a pipe breaks within SAWS' system, it's the utility's responsibility to fix it — in both cases, time is of the essence.

As SAWS staffers work through what is already promising to be another record-breaking season of water main breaks, here's a look at how the municipal utility prioritizes those leaks, from the smallest to the biggest, and everything in between.

How to report a leak

SAWS crews discover leaks in a number of ways, the most obvious one being from phone reports.

San Antonio residents who see a leak can report it to the water utility by calling 311 or 210-704-SAWS (7297). You can also report a leak online by visiting the SAWS website here.

SAWS dispatchers will then send out an investigator from their staff that same day to rate the severity of the leak and send repair crews out accordingly.

As of last year, SAWS had 52 repair crews made up of 208 employees, numbers it is currently working on increasing. Those repair crews report to four service centers located around the city, sticking to their quadrants to help for quicker response times.

Main break priority levels

SAWS has three priority levels for leaks and responds to each type differently. The three levels are Priority 1, 2 and 3.

A Priority 1 or “P-1” leak is an emergency main break, which is causing damage to roads or sidewalks or is causing a water service outage or loss of water pressure to nearby buildings, said Carlos Mendoza, SAWS vice president of distribution and collection operations. This would be a leak such as the water main break that took place on the Northeast Side in late May that left parts of Interstate-35 near Eisenhauer flooded.

These kinds of leaks are all hands on deck, with a SAWS repair team being sent out right then and there, Mendoza said. They may even be taken off the scene of a lower-ranking repair to dispatch right away to this type of leak, he said.

“We get to those immediately and we prioritize them as P-1 leaks,” Mendoza said. “We will send our crew out there even if they're on another leak that's not P-1.”

SAWS has three priority levels that determine how quickly the utility sends out a repair team. / Graphic Courtesy SAWS.

Priority 2 or P-2 leaks are main breaks that cause moderate to high water loss but do not cause damage or any sort of water service outages, Mendoza explained.

“This type of leak looks pretty bad,” Mendoza said. “It's running down the street, it's not great. We look at it, we assess if it is causing damage. If it's not causing damage, we prioritize that as a P-2 leak, and we'll get to it either the same day or within a couple of days.”

A Priority 3 or P-3 leak is usually not an immediate emergency, Mendoza said. This type of leak has low to moderate water loss that is pooling or running down the street. The majority of calls SAWS gets for leaks are these types of leaks, he said.

“Those are scheduled — believe it or not,” he said. “We have them scheduled, but again, we prioritize them [lower] and we get to them in chronological order.”

SAWS crews usually try to get to these types of leaks within one to two weeks, Mendoza said. At the most, it can take up to two full weeks during mid-summer, which is “main break season,” he said.

Finding the leaks

The water utility has also done a lot of work to assess the system and to map out where most of SAWS' leaks occur, Mendoza said. A majority of leaks happen on the city’s Northeast side, along Nacodoches Road, where old cement mains break easily as drying out soil shifts, he said.

SAWS heat maps here show its biggest problem areas within the city. Much of the city's old concrete pipes have issues on the northeast side while many of the old cast iron pipes within Loop 410 are also seeing issues. Credit: Lindsey Carnett / ISF FORUM.

Another hot spot is on the city’s Central Northside, where Loop 410 and U.S Highway 281 meet. Many leaks also occur inside Loop 410, where much of the older water pipe infrastructure is made of Post World-War II cast iron, Mendoza noted.

”We have a lot of leaks … in your older neighborhoods, where the infrastructure is getting older,” he said. “Obviously, we need to replace [and] repair pipe immediately in those areas.”

SAWS also proactively looks for leaks, said Patrick Shriver, SAWS water resource manager.

“When main break seasons happen [in the summer during droughts], those breaks mostly happen in areas where there's clay soil and movement and drying out or shrinking and contracting — that wreaks havoc on the joints,” Shriver said.

SAWS has a specialized team called their Leak Detection Team that actively goes out to these areas and use special equipment to listen to the ground — straining to hear specific “whooshing” noises that suggest a leak below the earth.

SAWS has a specialized team called their Leak Detection Team that actively goes out to problem areas and uses special equipment to listen to the ground — straining to hear specific “whooshing” noises that suggest a leak below the earth. Credit: Lindsey Carnett / ISF FORUM.

The team’s equipment looks straight out of an old 1940s film, with large headphones that cover the wearer’s ears completely, wires everywhere and a large electronic box with a handheld tool that looks like a fancy sink plunger connected to the box by a long thread.

This team can also help a working crew find out which direction a leak is going underground, if workers are unable to tell, Shriver said.

Adding staff

SAWS experienced the most main breaks within pipes delivering the city’s water supply ever in 2023 due to the scorching summer heat that led San Antonio to reach 75 triple-digit days last year.

To deal with the increased number of leaks, SAWS upped the number of staff members who respond to leaks, Mendoza said, adding 50 staffers to help detect, mark, and fix leaks last year, he said.

“We added approximately 10 more crews to our [four] different service centers,” he said. “I think the highest backlog that we've had over the whole year was about 250 leaks that we couldn't get to and then we brought that down — right now we're sitting right around 40 leaks in our backlog.”

SAWS updated conservation plan aims to make addressing water loss a priority for the utility over the next five years, which is why adding “boots on the ground” is essential, said SAWS President and CEO Robert Puente.

“One of the big concerns was the complaints … that someone reported a water leak and SAWS didn’t get to it for a week or 10 days, and that’s because we had a limited amount of crews available to go out and fix that leak,” Puente told the ISF FORUM. “This will allow us to be much more responsive to those complaints.”

Lindsey Carnett covers the environment, science and utilities for the ISF FORUM. A native San Antonian, she graduated from Texas A&M University in 2016 with a degree in telecommunication media...