FLOODSOne in Five Texans Lives in a Floodplain
Almost 6 million Texans, or about 20% of the population, live in an area susceptible to flooding and one-fifth of the state’s land is in a 100-year floodplain. Texas launched a statewide effort to harden Texas against floods and rising sea levels.
Almost 6 million Texans, or about 20% of the population, live in an area susceptible to flooding and one-fifth of the state’s land is in a 100-year floodplain, according to first-of-its-kind data gathered as part of a statewide effort to harden Texas against floods and rising sea levels.
The analysis is part of the Texas Water Development Board’s first statewide flood plan, still in development, which the Legislature required in a 2019 law passed in response to Hurricane Harvey. Flood risks in Texas are increasing as climate change brings heavier precipitation, stronger hurricanes and sea level rise and as the state’s population continues to climb.
More than 2.4 million Texans live in areas that have a 1% chance of flooding each year, known as the 100-year floodplain, the analysis found. Another 3.5 million people live in areas with a 0.2% chance of flooding each year, known as the 500-year floodplain.
Roughly 56,000 square miles of Texas now fall within the 100-year floodplain, TWDB staff said in a presentation this week.
It will likely cost Texas tens of billions of dollars to protect people and property from floods. The first projects proposed in the plan add up to $38 billion, including the massive coastal barrier proposal with its “Ike Dike,” a huge gate system proposed for the mouth of Galveston Bay.
“Getting this program up and running is a really big deal,” TWDB Chair Brooke Paup said before the board approved the 15 regional plans, a major step in creating the statewide flood plan. Each region is built around one of the state’s major watersheds.
“I know it’ll truly go so far to save lives and people’s homes,” Paup said.
As climate change worsens, higher global temperatures increase the amount of moisture in the air and thus the risk of extreme rainfall events, the Texas state climatologist and a national climate assessment have found. Heavier precipitation linked to climate change likely increased Hurricane Harvey’s total rainfall by as much as 19%, one study found. Almost 50 inches of rain fell in some areas of Houston during Harvey — the highest rainfall amount in a single storm for any place in the continental U.S.
