As the Blanco River rose rapidly early on May 24th, phones around Wimberley — most of which had 512 area codes — received urgent text alerts: danger, flooding, seek shelter. Laura McComb, who had a 361 area code, did not receive any such text.

Her house was eight feet in the air, on stilts, and by the time the family noticed water on the first floor, just after 1:00 a.m., it was too late to evacuate.

“They were forced to ride this thing out in the house,” recalled Steve Schultz, McComb’s father. “And unfortunately, a big cypress tree hit. And it was knocked off of its foundation.”

Ultimately, McComb and her two children — Andrew, 6, and Leighton, 4 — were killed in the flood, as were 28 others.

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Schultz provided emotional testimony about his daughter’s death to the Texas Water Development Board during an hourslong hearing Monday. He said he was calling for better flood detection and warning systems in the Hill Country and across Texas.

In November, Gov. Greg Abbott transferred $6.8 million from the state’s Disaster Contingency Account for the development of such systems and authorized the development board to manage the appropriations.

Schultz emphasized that surviving a flood is more difficult than the inexperienced might realize, especially because of the level of debris in the crashing waves. “It’s not like swimming in any normal water,” he said. “It’s like swimming in a cement mixer.”

In testimony, flooding experts from various agencies emphasized the need for faster and more responsive technology, both for tracking rising water levels and for communicating risk.

Mark Null, a head hydrologist at the National Weather Service’s West Gulf river forecast center, said several areas around Texas lack sufficient stream to measure water levels. Even the gauges that do exist don’t report their findings fast enough, he said.

“With some of the gauges out there, there’s a latency of the data arriving — up to an hour, or it could be even more. It could be two hours,” Null testified. “We’re not operating in real time.”

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At one point during the Wimberley floods, the Blanco River turned into a canyon of water that gained almost 20 feet in one hour — a situation far more urgent than the gauges could convey. By the end of the day, the water level had risen past 40 feet, destroying the river gauge.

That’s the reason the state's entire gauge system needs an increased level of “resilience and redundancy,” according to David Walker, a manager of river operations with the Lower Colorado River Authority.

“You have to have enough gauges out there to give you the total picture of what’s happening, so you can assess the quality of the information that’s coming in,” he told the committee. “And minutes matter.”

Even with better modeling and forecasting technologies, Texans will still be at risk if they aren’t sufficiently warned of incoming dangers, according to Mike Talbott, executive director of the Harris County Flood Control District. He said alert systems are lacking statewide.

“Tone and language are critical. Coordinated and concise language, that’s repeated, is critical to reducing damage and saving lives,” he told the committee. The goal is to disseminate “accurate and timely information which compels people and public officials to act,” he added.

Talbott said flood alerts often use the wrong channels, and even the wrong language, for their intended audience. He cited the high number of Texans who only speak Spanish — more than two million, according to the most recent U.S. census.

Any given alert should be “issued over a number of channels, to ensure it reaches the largest audience — who are able to interpret it,” he said.