As triple-digit days descend upon San Antonio, the San Antonio Water System staff is preparing for what is already promising to be another record-breaking season of water main breaks.

The municipal water utility 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.

Last year was San Antonio’s hottest since meteorological record-keeping began in the late 1800s — and the trend isn’t showing any signs of reversal.

SAWS experienced roughly 7,400 leaks in 2023, compared to the 6,400 it experienced in 2022 and the 4,800 in 2021, according to SAWS data — the majority of which occurred during the summer, said Carlos Mendoza, SAWS vice president of distribution and collection operations.

As severe drought persists across the Central Texas region, SAWS is already preparing its staff for “the same or more” main breaks this summer due to contracting soil disrupting pipes, Mendoza said.

“What we’re doing to prepare for that — we’re here doing a better job cutting down our response time to make sure that we get to these leaks faster, [and] we’re looking at our crews to see where we can better respond to the leaks,” he said.

A majority of these leaks are taking place within Loop 410, where the city’s older infrastructure is located, Mendoza noted. This is especially true where U.S. Highway 281 and Loop 410 intersect, due to the black clay soil that resides in that area of the city, he added.

“What we’re seeing in the city right now for us, is it’s our cast iron pipes — a lot of that 60-year-old pipe, 50-year-old pipe is coming to the end of its useful life, so we have a program to replace those pipes,” Mendoza said. Older cement pipes, which are also coming to the ends of their 50-year-life spans, are breaking often too, he said.

Since the early 2000s, SAWS has been using high-density polyethylene (HDPE) pipes for new installations, a type of flexible plastic that is food-grade safe and less likely to break from shifting soil, said Gilbert Santos, a SAWS operations manager.

Main breaks are more likely during periods of intense heat because the soil dries out and shifts, which can cause the pipes to also shift, Mendoza explained.

Gilbert Santos, a SAWS manager of Northeast operations for distribution and collection points to Hymax coupler which patches a leaking pipe quickly and safely.
Depending on the size of the break, a Hymax coupler could be used, which patches a leaking pipe quickly and safely. Credit: Scott Ball / San Antonio Report

‘Main break season’

Older pipes are more likely to break at their joints, said Patrick Shriver, a SAWS manager in water resources. SAWS is entering its “main break season,” Shriver said, which is when the utility’s crews are typically busiest.

For SAWS last year, that season was from July through September, although it can also be between May and September, depending on the rainfall each year, Mendoza said.

“Most people don’t realize there are sections of pipes that are joined, where they come together and they’re not all just one piece,” Shriver said. “When main break season happens, that mostly happens in areas where there’s clay soil — and movement in the drying out or shrinking and contracting of soil wreaks havoc on those joints.”

To deal with the increased number of leaks last year, 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.

SAWS is looking to add even more staff members this year for the additional needs, Mendoza said.

“We have four major service centers across the city that we operate out of,” he said. “I think the highest backlog that we’ve had over this whole year was about 250 leaks that we couldn’t get to [immediately] and we brought that down. Right now we’re sitting around 40 leaks in our backlog, so this is kind of the calm before it really starts back up.”

While SAWS was able to squeeze these 50 new employees in under its existing approved budget last year, Mendoza did note additional funding may be needed in the future to hire more staff as the system continues to grow.

“What we’re looking at in the future would be an increase in our budget,” he said. “So with that, we would need the rates to support that as we go forward. We don’t know what that looks like yet. We’re just assessing that now.”

Asked about how many gallons of water the system lost last year due to the increase in main breaks and leaks, Mendoza said he didn’t have an exact figure ready off the top of his head but noted this loss is known within SAWS as “non-revenue water.”

“I don’t know exactly the amount of water that we’ve lost on an annual basis,” he said. “[But] we need to really look and focus our efforts to control that loss. … From what I understand, it can be as much as a new water source here in the city.”

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