By Antigone Barton
If the rewards of life by the sea are immeasurable, a report released last month showed the risks, at least, are calculable.
Global warming, rising sea levels and storms all add up to odds of flooding that will redraw the map of Florida from the bottom up, according to the report, impacting mainland as well as barrier island communities. And while Palm Beach County may stay drier longer, data from the report show the odds that flooding will affect residents from South Palm Beach to Boca Raton in next two decades.
Interactive maps released with the Surging Seas report by Climate Central, a nonprofit research and education group, show the estimated effects of rising sea levels to more than 3,000 coastal towns, cities, counties and states in the contiguous United States during the next century, with storms bringing flooding from 1 to 10 feet above mean high tide level.
More than half of the population in the line of floodwaters live in Florida. Miami Dade is most at risk for flooding, with Broward County right behind it. The next neighbor up, Palm Beach County, however, is not even among the top 10 most flood-prone counties.
“A small amount of elevation makes a big difference when it’s so flat,” said Ben Strauss, Climate Center director on the Surging Seas project.
According to the maps, at http://sealevel.climatecentral.org/, Boca Raton, the county’s southernmost coastal town, would feel the greatest impact from storm surges in this area. The reports data predict 1,212 Boca Raton homes would be vulnerable to flooding from a 3-foot storm surge that has a 1-in-6 chance of occurring by 2030. The area faces 1-in-2 odds of such a surge by 2050.
That is just one factor determining the numbers of people and homes that would be affected — with population density, building height and nearness to the shoreline adding to, or ameliorating, risks.
A climb up the interactive map illustrates the risks, with 525 homes in Highland Beach — or 15 percent of its housing — threatened with flooding in a 3-foot surge. Delray would have the second highest number of homes facing flooding, with 1,081 homes 3 feet or less above the mean high tide line. Low-density Gulf Stream would have 73 homes in the line of flood waters, while the more crowded neighboring town of Briny Breezes would see flooding 294 homes, or 37 percent of its housing.
While 150, or 10 percent, of Ocean Ridge homes would be affected by a 3-foot surge, life on the mainland has its own risks, the maps show, with 649 homes in the way of waters rising from canals and the Intracoastal in Boynton Beach within the next two decades. Maps for Lantana and Manalapan show Hypoluxo Island vulnerable on all sides. In Lantana, 290 homes are less than 3 feet above mean high tide, and in Manalapan 21 homes would be affected, according to the maps.
And while sea walls, such as those that line the entire oceanfront side of South Palm Beach, may offer protection, they present a problem as well, Strauss said.
“It’s impossible to build a sea wall that will work in the long term.” And, he added, “New Orleans and Katrina showed us, once that is breached, it is harder to move water out.”
Surging Seas data predict 113 South Palm Beach homes, or 8 percent of the town’s housing, would be affected by a 3-foot storm surge.
“In the long term, the map of Florida is going to be redrawn,” Strauss said. “In the near term, we’re going to see more and more floods go higher and higher.”
The response, he said, “It’s a question of what our tolerance for risk is.”
Homeowners can respond by literally raising their properties with higher foundations, an expensive but not impossible proposition. They also can consider moving their valuables elsewhere, and keeping a pump handy.
Communities can consider the report’s findings and other data, when planning, he said.
In principle, Treasure Coast Regional Planning Council already does, said Michael Busha, the council’s executive director, discouraging further development of barrier islands, investments in new infrastructure that encourages development in barrier islands, and encouraging public beach access.
On a larger scale, the report may cause individuals and communities to take an active interest in environmental policies that may slow climate change, and sea level rise, Strauss said.
“But a lot of increase is already baked in the cake,” he added. “We won’t be able to avoid it.”
By Antigone Barton