Today, one in four parts of all critical infrastructure in the United States — including police, fire stations, hospitals, airports, and sewage treatment facilities — is at high risk of becoming inoperable due to flooding, according to a new report released today by The First Street Foundation, a nonprofit research and technology group that assesses the threat posed by flooding across the country.
The report also found that nearly two million miles of roads – 23% of US roads – are already at risk of becoming impassable due to flooding.
To provide what First Street says is the most complete picture to date of community-level flood vulnerability, researchers examined five categories across the Lower 48 District and the District of Columbia: critical infrastructure; social infrastructure, including museums, government buildings, and schools; roads. commercial real estate; and residential property.
The report used operational flood risk estimates from official governing bodies to determine how much flooding would take to destroy different types of offline facilities or services. The researchers then covered the types of flooding events that could be expected in an area at least once every two years to gauge community risk.
“Even if your home is safe and secure from the intensity of flooding, if flooding becomes more common and destructive to your community, your property value may be threatened as well,” said Hamed Mefkhari, associate professor of environmental engineering at the university. Alabama, who was not involved in the First Street Report.
Where the flood risk is greatest today
If there is zero point in flood risk in the United States, it is Louisiana.
The state is home to six of the country’s 20 most vulnerable counties. The Diocese of Cameron in southwest Louisiana is the most vulnerable county in the United States, followed by the Diocese of Orleans, which includes New Orleans.
Jeremy Porter, head of research and development at First Street, said that while New Orleans has adapted its infrastructure and levees to fend off powerful storms, continued sea level rise and more destructive hurricanes may eventually overwhelm the city’s current defenses.
“It will have to be constantly updated as the environment changes in the future,” Porter said. “The infrastructure that exists today is not going to protect New Orleans in five, 10 or 15 years. It’s going to get worse as sea levels rise, as storms not only become more frequent, they get stronger.”
In both Cameron and Orleans Parish, the report found that more than 94% of all critical infrastructure — including police and fire stations, critical to emergency response operations after disasters such as hurricanes — is at risk of being out of action.
Florida is also home to some of the country’s most flood-prone counties, but flood risks are not limited to coastal areas. First Street researchers said that several areas in Appalachians, such as McDowell County in West Virginia and Johnson County in Kentucky, are also among the most vulnerable areas due to the growing threat of torrential rain.
As the planet warms due to human-caused climate change, a warmer atmosphere could hold more water, causing extreme rainfall events to dump massive amounts of water in short periods of time.
“Because of the effects of climate change, there are communities across the United States that will make difficult decisions in the coming years because of sea level rise and storm severity,” Morstad told CNN. “It’s not just the coast of Louisiana.”
Bill to help mitigate flood risks
The bipartisan bill also contains billions of dollars in funding to improve roads and energy infrastructure, and to make the power grid more modern and resilient to strong storms.
Louisiana’s only Democratic congressman, Troy Carter, told CNN in a statement that he wanted to see the infrastructure bill passed.
“I still hope the Louisiana delegation will not bring up the history of bipartisan infrastructure negotiations,” Carter told CNN. “I am grateful that Senator Cassidy has stood with me in this effort. I do not plan to return to my constituents empty-handed.”
Scalise spokespeople and Representative Clay Higgins — a Republican who represents Cameron Parrish — did not respond to CNN’s requests for comment on how they would prefer to help flood-prone communities in their areas.
Things will get worse
Over the next 30 years, the number of residential properties at risk of flooding is expected to rise from 12.4 million today to 13.6 million by 2051, according to the report. For critical infrastructure and commercial properties, the number of facilities at risk is expected to grow by 6% and 7%, respectively, over the next three decades.
Geographically, the report finds that flood threats will increase along the Atlantic and Gulf coasts, but that significant increases in vulnerability are also expected across large parts of the Pacific Northwest.