Estimated Cost to Curb Texas Flooding Over 10 Years is $31.5B

The cost to curtail damaging flooding across Texas over the next 10 years is more than $31.5 billion and state officials are urging lawmakers to adopt legislation meant to end a cycle of “repairing and rebuilding,” according to a series of recommendations released Thursday.

The Texas Water Development Board provided the recommendations to lawmakers ahead of the legislative session that begins next month. They’re part of an updated TWDB flood assessment report that says coastal and river flooding alone is expected to cause more than $6.8 billion in property losses over the next five years.

The agency is seeking a three-pronged approach: update flood mapping and modeling, establish comprehensive planning rather than piecemeal efforts, and enact policies and procedures to aid mitigation.

“Due to a combination of population growth and related development, Texas can be certain that without proper planning, flood events will impact more lives and cause more damage in the future,” the report said. “This statement is just as true on the High Plains near Post as it is along Dickinson Bayou near Galveston.”

Much of Texas is either unmapped or uses outdated ones, resulting in “widespread misunderstanding about true flood risks,” the report said. For instance, more than half of the flood insurance claims filed this year have occurred outside of areas identified as high-risk flood zones. The cost of updating flood-risk maps for all Texas watersheds is an estimated $604 million, according to the TWDB, which is the lead state agency tasked with water planning, data collection and other services.

“Despite 50 years of concerted effort and extensive participation by Texas communities, we find ourselves repairing and rebuilding instead of planning and preventing,” the board said in the report.

Larry Larson, senior policy adviser for the Association of State Floodplain Managers, said the board is right to promote a more comprehensive approach to curtail flooding, explaining that isolated efforts have little benefit.

“Most of the thinking in the Houston area has been let’s develop the hell out of it and expand the tax base,” Larson said, adding that the aftermath of Hurricane Harvey has largely changed that mindset.

David Maidment, an engineering professor at the University of Texas with an expertise in water resources planning, said coordinated efforts by the National Oceanic and Atmospheric Administration, the National Water Center at the University of Alabama and others has led to significant advancements in hydrologic analysis and forecasting.

“We’ve accomplished more in research in the last five years than in the previous 36 years of my career,” said Maidment, adding that “Texas has been the prototype for the development of a national forecast flooding system for the whole country.”

The population in Texas is projected to increase to nearly 42 million people by 2050, the TWDB noted in its report, with much of this growth occurring upstream and downstream of our major metropolitan areas. There needs to be a concerted effort to encourage sound land use that minimizes flood damage, according to the agency.

TWDB spokeswoman Merry Klonower said if lawmakers enact the agency’s recommendations, it would lay the foundation for comprehensively managing flood threats.

Developing flood maps for all watersheds and better planning represent “a new suite of activities and a new approach to identifying and minimizing flood risk for all Texans,” Klonower said Thursday.