Why were the Texas floods so catastrophic?

Cars and debris were scattered as devastating flooding hit Texas. (Photo: Eric Vreen via Getty Images)

A powerful storm slammed into the Texas Hill Country early Friday morning (July 4), dumping nearly a foot of water in just a few hours. Within 45 minutes, water rushed from the region’s hills into the Guadalupe River, which rose more than 26 feet and overflowed its banks. In Kerr County, the torrent washed away people, homes, and infrastructure, and the death toll has surpassed 100 as of July 8.

What are the causes of such a catastrophic flood?

For one thing, the region is prone to flash flooding. Texas, in fact, ranks first in the U.S. for flood deaths. That’s partly due to its hilly terrain and semi-arid soils, which don’t absorb water well, as Hatim Sharif, a professor of civil and environmental engineering at the University of Texas at San Antonio, wrote in an article for The Conversation. “The water drains quickly, and small streams can rise quickly.”