Texas flood plan: 5 million people at risk in flood-prone areas

More than 5 million Texans, or one in six people in the state, live or work in areas prone to flooding, according to a draft of Texas’ first-ever flood plan.

The Texas Water Development Board (TWDB) created this plan to reduce flood risk and address rising sea levels, as mandated by a 2019 state law passed in response to Hurricane Harvey.

The public can comment on the plan during a meeting in Austin on May 30, with online comments accepted until June 17.

Released in early May, the plan estimates that nearly 1.3 million Texas homes are in flood-prone areas. Sarah Kirkle, director of policy and legislative affairs for the Texas Water Conservation Association, noted the plan’s significance in providing the most comprehensive view of flood-risk areas in the state.

Using existing flood data, the plan maps out flood-prone regions, filling gaps with local knowledge and data from the flood risk modeling company Fathom.

“When the plan is approved, it will be a historic moment for Texas,” Kirkle said. “It will be crucial in understanding topography to plan for flood risks properly.”

Climate change is exacerbating flood risks in Texas by causing heavier rainfall, intensifying hurricanes, and raising sea levels, which may lead to larger and more frequent river floods.

Texas has a history of flooding, with Hurricane Harvey being the wettest tropical cyclone in U.S. history, causing nearly $125 billion in damages. More recent heavy spring rains have also caused widespread flooding in Southeast Texas.

The draft state flood plan indicates that over 2.4 million people live or work in a 100-year floodplain, areas with a 1% annual chance of flooding, while another 2.8 million are in a 500-year floodplain, with a 0.2% annual chance of flooding.

Approximately one-fourth of Texas’ land, or about 67,000 square miles, falls within these floodplains, and every county in the state has experienced at least one federally-declared flood disaster since 1953.

The plan includes legislative recommendations from the TWDB and 15 regional groups anchored by major state watersheds. It estimates that recommended flood mitigation projects could cost over $49 billion, with more than half allocated to the “Ike Dike” project, a coastal barrier to protect the Houston region from hurricane storm surges. The TWDB recommends additional funding from state lawmakers for flood mitigation and prevention projects.

The state’s Flood Infrastructure Fund, established in 2019, has provided nearly $644 million through loans and grants to local governments for drainage and flood mitigation projects. Lawmakers have allocated about $1.4 billion for the fund since its creation.

Kirkle noted the challenge of funding flood mitigation strategies without a reliable revenue source, emphasizing the need for lawmakers to approve additional funding each legislative session.

The TWDB also recommends implementing a statewide flood early warning system to alert residents via social media, radio, and reverse 911 calls. Additionally, the board suggests a technical assistance program to help small, remote, rural, and disadvantaged communities apply for grants or loans.

The plan highlights that over 70% of flood fatalities in Texas occur when people attempt to cross flooded low water crossings. The TWDB recommends funding for removing these crossings, improving signage, and enhancing bridge safety.

Due to limited funding for flood projects, the regional groups propose allowing counties to collect drainage fees in unincorporated areas, which only cities can currently do. This would help counties finance flood mitigation and drainage projects.

According to a 2023 Nationwide Stormwater Utility Survey by Western Kentucky University, only about 150 of the 1,450 cities and counties in Texas have dedicated drainage fees.

Cyrus Reed, conservation director for the Lone Star Chapter of the Sierra Club, praised the plan but noted its limitations, such as relying on outdated models that use historic rather than future climate variables.

TWDB will finalize the plan this summer and present it to the Legislature by September 1.