New FEMA flood maps expand 100-year floodplain in Harris County

Officials say no immediate changes to insurance requirements or development regulations

Published on Feb. 11, 2026

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New draft FEMA flood maps show an expanded 100-year floodplain across much of Harris County, reflecting increased rainfall rates and lessons learned from major storms like Hurricane Harvey. However, officials stress the maps are still in draft form and no regulatory or insurance changes will take effect immediately.

Why it matters

The updated mapping is part of FEMA's effort to incorporate local expertise and updated data, as it became clear after recent major storms that existing floodplain maps were not fully reflecting flood risk. Thousands of homes flooded outside of previously mapped high-risk areas.

The details

The draft maps show expansions in several areas, including parts of northeast Harris County, along upper Greens and Halls bayous, parts of Keegans Bayou and Brays Bayou in southwest Houston, the backside of Addicks Reservoir, and some areas of Bellaire. While a few areas were removed from the 100-year floodplain, most changes reflect expansion. The maps also display areas that may pond during a 100-year rainfall event, even if they were not previously mapped within the traditional floodplain.

  • FEMA has released the draft mapping information to the 34 floodplain administrators in Harris County for technical review.
  • The Flood Control District plans to launch a public-friendly online map viewer next week displaying the same draft data.
  • Officials also plan to host informational webinars and continue working with floodplain administrators and community stakeholders.

The players

FEMA

The Federal Emergency Management Agency, which is leading the effort to update the floodplain maps for Harris County.

Harris County Flood Control District

The local agency supporting FEMA's MAAPNext initiative to incorporate local expertise and updated data into the new flood maps.

Jim Blackburn

An environmental lawyer and professor at Rice University's civil and environmental engineering department, who provided expert analysis on the implications of the new flood maps.

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What they’re saying

“I think it'll come as no surprise to a lot of the people that are whose homes are now mapped as being in the 100 year flood plain that weren't previously in the mapped flood plains.”

— Jim Blackburn, Environmental lawyer and professor (khou.com)

“Well, our flood risk is going up because our rainfall levels are going up as well. I mean, this is a direct response to the larger storms that we've been seeing, really for the last 25 years or so.”

— Jim Blackburn, Environmental lawyer and professor (khou.com)

What’s next

The draft maps are still under review, and FEMA has not yet initiated the formal public appeal and comment process. Officials say nothing changes immediately regarding flood insurance requirements or development regulations.

The takeaway

The updated flood maps reflect the growing flood risk in Harris County due to increased rainfall rates and the lessons learned from major storms like Hurricane Harvey. While the maps are not yet final, they serve as an important tool for residents, businesses, and local governments to better understand their flood risk and make informed decisions.