The Texas Hill Country has been notorious for flash floods caused by the Guadalupe River. Here's why the area is called "Flash Flood Alley."

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.

More than 111 people have died across six counties after flash flooding from heavy rain began affecting the state last week.

Rain rushing to the Guadalupe took it from a depth of less than 8 feet to 37.5 feet, a deluge with as much volume as an aircraft carrier over five minutes.

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.

Also: San Antonio mourned the victims in a Travis Park vigil; UTSA said one of its teachers died in the Guadalupe River flood; Kerrville officials said a privately owned drone collided with a helicopter conducting search and rescue operations.

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.

Lt. Gov. Dan Patrick signaled that he plans to push for the state to pay for sirens erected alongside the Guadalupe River in the wake of the devastating flash floods that led to the deaths of over 100 people.

Without a modern flood warning system, emergency officials monitor four sensors along the Guadalupe River – including one that was knocked out in the