After summer wildfires, why some areas are at high risk for flash floods
mid an active summer wildfire season that led to several blazes in and around Central Texas, Monday’s forecasted rainstorm could spell flood risks for recently-burned areas.
Burn scars are areas where recent fires have stripped the vegetation from the region, leaving no buffer between the soil and the elements
That means there’s no trees, bushes or even leaves on the ground to soak up some of the rain, leading to supersaturation within the soil, said Karl Flocke, a woodland ecologist with the Texas A&M Forest Service.
When an area has been recently burned by a fire, that means the rain will hit the soil at a higher speed, washing off the ground into any surface water channels like canyons, creeks and rivers.
“Without that vegetation, a lot more water is going to run off the surface,” he said. “And in a large rain event like we’re potentially about to see, that can lead to increased risk of flash flooding over burned areas.”
“All of that is really up in the upper reaches of Crabapple Creek,” Flocke said. “So if a lot of water falls on that 1,000-plus acre fire, it’s all going to flow into Crabapple Creek.”
Ahead of Monday’s rainstorm, Flocke stressed the importance of residents following all local weather advisories, especially the National Weather Service’s flash flood watches and warnings.
For people who live downstream from a recent fire, he added they need to pay close attention to rainfall and watch for low water crossings.