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.

At least 120 people are dead and 173 are missing in central Texas after the Guadalupe River swelled early Friday, causing destructive flash flooding throughout Kerr County.Now, new before-and-after satellite images of several sites throughout Kerry County show the devastation caused by the floods as crews embark on a seventh day of search and rescue efforts.

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.

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.

As a climate scientist who calls Texas home, I can tell you that the Hill Country of Texas is no stranger to flooding. Meteorologists often refer to it as “Flash Flood Alley” because of its steep terrain,