In a city infamous for its flooding, something as innocuous as rain can prove to be disastrous or even deadly. Small increases in the amount of rainfall over time can have significant consequences today, said Ed Emmett, fellow in energy and transportation policy at Rice University’s Baker Institute for Public Policy and former Harris County Judge, as he led the daylong conference “Redrawing Risk: What FEMA’s New Flood Maps Mean for Greater Houston.”
Co-hosted by the Baker Institute and Kinder Institute for Urban Research, the event explored the real-world implications of the flood mapping system FEMA revised in February and what the changes could mean for homeowners, developers, policymakers and local governments across the region. Not only were the panelists experts in flooding and flood control, the audience was packed with leaders from organizations and communities potentially affected by flooding. This included two candidates in the primaries for Harris County Judge, Annise Parker and Orlando Sanchez.
The conversation focused on the far-reaching effects of the long-awaited map revisions, which come after nearly two decades without major updates and could influence everything from insurance requirements and development regulations to where residents choose to live. As the nominal 100- and 500-year floods have significantly increased their rate, flood maps are no longer viewed in isolation. They’re being evaluated alongside socioeconomic conditions and population trends to provide a more complete and accurate picture of risk and the consequences of risk, said David Satterfield, former U.S. ambassador and director of the Baker Institute.
“Those updates carry significant implications not only for Harris County residents but for home buyers across the United States,” he said. “They shape how people assess their exposure, how communities should plan and how decisions are made about where and how to build in Harris County alone.”
Texas has led the nation in population growth for the second year in a row, and Houston can serve as an example to the entire country on how to create community resilience, Satterfield said. Houston’s development has often been described as “paving over prairie,” but that’s not unique to Harris County — it exists across the nation. As investments in mitigation efforts continue to increase, there’s a need to think about the relationship between land use, real estate markets and major infrastructure investments, he explained.
“Land use decisions, together with engineering and public works, can mitigate risk, particularly when aligned and guided by reliable data, and these draft flood maps demonstrate that this is an area where research institutions, including our centers here at the institute for energy studies and tax and budget policy, and our partners at the Kinder Institute are deepening our understanding through surveys and modeling of how risk is evolving and how it can be managed more effectively,” Satterfield said.
Harris County has already made substantial investments in drainage, flood control and data-driven planning efforts that are reshaping how risk is measured and managed across the region. Yet the FEMA maps show that, for instance, the 100-year floods have increased from predicting 13 inches of rain in a 24-hour period to 16 or 18 inches.
“You think about 5 inches of rainfall increase across all of Harris County for a 100-year storm — we’re talking about 150 billion gallons of water across the region,” said Andy Palermo, managing senior principal at EHRA Engineering.
Rainfall will always be the main contributor to flooding, explained True Furrh, a doctoral student and graduate research assistant at Rice’s Severe Storm Prediction, Education and Evacuation from Disasters (SSPEED) Center. He emphasized the growing importance of data-driven planning, noting that newer modeling tools project a 28% increase in flood risk as they account for the heavier rainfall patterns and more extreme weather events that have happened since 2020.
In a panel with Russ Poppe, first assistant engineer for Fort Bend County and former director of the Harris County Flood Control District, and Yilun Cheng, investigative reporter at the Houston Chronicle, Emmett walked through FEMA’s revised maps neighborhood by neighborhood. Using localized examples with the help of the audience, the panel helped translate technical data into a clearer picture of how flood risk has changed across the region.
The conference also explored how communities can better prepare through equitable mitigation strategies, including green infrastructure, nature-based solutions and, in some cases, managed retreat, while balancing the psychological, financial and physical impacts flooding has on residents.