Officials balked at the cost for installing a siren warning system and the potential for sirens to blare in the middle of the night and wake up

In what experts call "Flash Flood Alley," the terrain reacts quickly to rainfall steep slopes, rocky ground, and narrow riverbeds leave little time for warning.

With more than 170 still missing, communities must reconcile how to pick up the pieces around a waterway that remains both a wellspring and a looming menace.

In the last nine years, federal funding for a system has been denied to the county as it contends with a tax base hostile to government overspending.

Plans to develop a flood monitoring system in the Texas county hit hardest by deadly floods were scheduled to begin only a few weeks later.

Walston drove from his home to the Center Point Bridge on FM 480 near Highway 27, where he shot video of the river below. He recorded nearly 38 minutes of surging water as it rose over 20 feet, carrying massive cypress trees, debris and even a house.

Flash flooding is common enough around the crescent-shaped region from Dallas through the Hill Country, the area earned the nickname "Flash Flood Alley."

Survivors have described the floods along the Guadalupe River as a “pitch black wall of death” and said they received no emergency warnings.

Here's what to know about the deadly flooding, the colossal weather system that drove it and ongoing efforts to identify victims.