Texas’ First State Flood Plan Released
8/15/24 – The Texas Water Development Board (TWDB) released the state’s first state flood plan today. And it’s full of eye-popping factoids.
For instance: More than a quarter of the state’s land and one sixth of the state’s population are in floodplains. So flood mitigation and prevention rank as high priorities. The entire plan stretches more than 500 pages. It listed and prioritized 147 pages of evaluations/studies, projects, strategies in tiny type.
Fifteen regional groups, each representing one of the major river basins in Texas, compiled the plan.
I will dig into more detail in coming days. But today, here are some quick facts from the executive summary to whet your appetite.
Structures Affected by Flooding
Planning groups identified approximately 878,100 buildings within the 1 percent (100-year) annual chance floodplain, and an additional 786,100 buildings within the 0.2 percent (500-year) annual chance floodplain. Total: 1,664,200.
More than 6,258 hospitals, emergency medical services, fire stations, police stations, and schools are within the 1 percent (100-year) and 0.2 percent (500-year) annual chance floodplains.
Regional flood planning groups also identified 9,322 low water crossings within flood hazard areas.
Increases in Flooding Forecast
The projected future condition 1 percent (100-year) annual chance floodplain is estimated to increase by 11 percent over the existing flood hazard area to a total of 62,245 square miles.
The regional flood planning groups project an increase of approximately 2.6 million people and 740,000 buildings in the 1 percent annual chance floodplain under projected future condition flood hazard.
Boggling Number of Recommendations
The regional flood planning groups recommended 4,609 flood risk reduction solutions: 3,097 flood management evaluations, 615 flood mitigation projects, and 897 flood management strategies in the regional flood plans with an estimated total implementation cost of more than $54.5 billion.
Floodplain Buildings
A total of 1,239 Texas communities and counties with flood-related authority participate in the National Flood Insurance Program.
More than 500 Texas entities have floodplain management standards that exceed National Flood Insurance Program minimum standards.
Costs
The plan includes recommendations in three categories: Evaluations/surveys; Projects, Strategies. The total cost of recommended:
- Flood management evaluations exceeds $2.6 billion.
- Flood mitigation projects totals is more than $49.1 billion; nearly half of this cost is associated with the Galveston Bay Surge Protection Coastal Storm Risk Management project.
- Flood management strategies exceeds $2.8 billion.
Planning groups reported sponsors requiring financial assistance with 80-90 percent of the costs to implement recommended flood risk reduction solutions.
Potential Benefits
Planning groups reported an estimated 843,339 people and 214,292 buildings would be removed from the 1 percent annual chance floodplain if the state flood plan was implemented.
Three regions identified potential water supply benefits for 37 recommended flood mitigation projects and one region recommended a flood management strategy with a potential water supply benefit.
Legislative and Policy Recommendations Included
The flood planning groups included legislative, administrative, and policy recommendations in the regional flood plans, and their policy recommendations informed the development of many of the legislative and floodplain management recommendations in this plan.
For More Information
This page on the TWDB site contains all the elements from the first state flood plan. But warning, the file sizes are large. And the spreadsheet listing all the projects is wide and best viewed on a large monitor.
I have reduced the file size of three of Texas State Flood Plan docs and am posting them here to make them easier to download.
Posted by Bob Rehak on 8/15/24
2543 Days since Hurricane Harvey