Hundreds of thousands of Floridians will have seawater flood homes

Palm Beach County will have 150,000 people living in areas at risk of sea water inundation if ocean levels rise as predicted through the year 2100.

Nationwide, 13 million people will live in homes that could be flooded by rising seas, according to a new study released Monday that looked at the vulnerability of coastal counties nationwide.

The paper is the first major study to assess the risk from rising seas using year 2100 population forecasts, according to its authors.

A bench off Lake Trail in Palm Beach sits surrounded after water washed in from the Intracoastal Waterway. A combination of the full moon, high tide, and sea level rise are blamed for the flooding. (Lannis Waters / The Palm Beach Post)
A bench off Lake Trail in Palm Beach sits surrounded after water washed in from the Intracoastal Waterway. A combination of the full moon, high tide, and sea level rise are blamed for the flooding. (Lannis Waters / The Palm Beach Post)

Titled “Millions projected at risk from sea level rise in the Continental United States,” the study is based on analyses by Jason Evans, an assistant professor of environmental science at Stetson University, and two researchers from the University of Georgia: Mathew Hauer, director of the Applied Demography Program, and Deepak Mishra, an associate professor within the Department of Geography.

“This analysis helps put numbers on something long suspected, but that previously couldn’t be quantified very well,” said Evans. “That rapid development of low-lying coastal areas is putting more and more people at risk of impact from sea level rise.”

Evans said Florida is “by far” the most vulnerable state in the nation to sea level rise, with Monroe, Broward and Miami-Dade counties at the top of the list.

Read: Sea levels rising at fastest rate in 3,000 years. 

About 83 percent of Monroe County’s future population will live in areas that could be flooded by 2100. Scientists believe seas could rise 6 feet by 2100.

In Broward County, 37 percent of the population is expected to be impacted by 2100, while in Miami-Dade County, it’s 36 percent.

The study also looked at how many people would be affected if seas rose 3 feet.

In Palm Beach County, about 26,100 people would likely have to relocate if seas rise 3 feet.

Estimates on how many people will be affected if seas rise three feet by 2100.
Estimates on how many people will be affected if seas rise three feet by 2100.

“For Floridians, the biggest take-home message is that our state is by far the most vulnerable in the nation to this climate change-driven hazard,” said Evans.

This study also provides a measure of potential flooding risks in some of the nation’s fastest-growing communities. In fact, more than a quarter of those living in Miami could face coastal flooding by the end of the century if adaptive measures aren’t taken.

Other areas of the nation that could face severe impacts include Tampa, Charleston, S.C., Poquoson, V.A. and Cape May, N.J.

“Current development patterns are continuing to worsen this vulnerability, despite increasing knowledge about the rates of sea level rise and areas likely to experience future impacts,” Evans added.

A bicyclist heads up Lake Trail in Palm Beach after it flooded Oct. 27 when water rushed in from the Intracoastal Waterway. A combination of the full moon, high tide, and sea level rise are blamed for the flooding. (Lannis Waters / The Palm Beach Post)
A bicyclist heads up Lake Trail in Palm Beach after it flooded Oct. 27 when water rushed in from the Intracoastal Waterway. A combination of the full moon, high tide, and sea level rise are blamed for the flooding. (Lannis Waters / The Palm Beach Post)

New storm surge map shows deadliest areas during hurricane

Hurricane experts repeat a mantra that more people die from storm surge than high winds during tropical storms and hurricanes.

To that end, the National Hurricane Center has been working on storm surge maps that will alert coastal areas about potential flooding and how high the water may get depending on proximity to the shore.

Those maps become operational this year and will be issued when the initial hurricane watch is made. In some cases it will be issued with the initial tropical storm watch.

The storm surge maps began an experimental phase in 2014.

A sample storm surge map for Fort Myers shows how far inland the water could reach from a tropical cyclone.
A sample storm surge map for Fort Myers shows how far inland the water could reach from a tropical cyclone.

“The problem is people prepare for wind and make assumptions about the strength of a hurricane based on wind,” said National Hurricane Center Director Richard Knabb in a presentation last year to Palm Beach County emergency managers. “We need to be thinking about all of the hazards.”

What would happen if Palm Beach County was hit by a Category 5 hurricane. 

Between 1963 and 2012, 49 percent of tropical cyclone deaths were storm surge related. Another 27 percent were attributed to rain accumulation.

Just 8 percent of deaths were from wind.

In 2005, Palm Beach County had just two evacuation zones. Now there are five based on the category of hurricane and how much water it will push ashore. Wind damage is less of a concern than storm surge.

“Wind gets the headlines, but it’s other hazards as well that we should be aware of,” said National Weather Service Warning Coordination Meteorologist Robert Molleda, who spoke at the same 2015 seminar as Knabb.