Outdated Flood Definitions Means Texas Bridges May Not Be Fit For Today’s Storms

The bridges were built to take on 50-year storms, but that engineering is based on data from the 1950s.

By Jill AmentOctober 19, 2018 11:11 am

The Ranch Road 2900 bridge in Kingsland was torn apart and swept away by a surging Llano River. It’s the third bridge in as many years to be swept away in a Texas flash flood. The bridges were built to take on 50-year storms, according to the Texas Department of Transportation, but changing climate patterns might call for changes in how they’re engineered – that will also require updated definitions of storms from the National Weather Service.

Sean Collins Walsh, a reporter for the Austin American-Statesman, says that the National Weather Service is reevaluating its definitions of storms, and that flood maps will be updated since rainfall levels have been higher in recent decades. He says that no one has updated the data since the 1950s.

What you’ll hear in this segment

-How TxDot designs its bridges to withstand floods

-How flood data will be updated to reflect more recent flash-flood and storm patterns

-Why many bridges are more vulnerable now than when they were built


Written by Alexia Puente.