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Water floods the Low Battery during Tropical Storm Irma on Sept. 11, 2017. File/Matthew Fortner/Staff

The Army Corps of Engineers will soon begin an investigative study of the flood risks on the Charleston peninsula — a critical step to get the federal government's help to protect the historic heart of the city from rising seas and worsening storms.

City officials will meet with the federal engineers in two weeks to come up with the parameters of the study, but in general, they'll be looking at the major flood risks facing the peninsula and identifying the most vulnerable spots.

From there, the Army Corps could recommend a major infrastructure project such as a protective sea wall, which it helped fund and build in many other places. 

That will all depend on the study's outcome, and whether such projects pass the Army Corps' rigid cost-benefit analysis.

The $3 million study, funded entirely by the Army Corps, is part of the $111 million federal effort to examine possible flood reduction strategies in dozens of communities in 14 states. Folly Beach is also among them.

Charleston's Chief Resilience Officer Mark Wilbert said the city also submitted an application for outer West Ashley, but only the peninsula was chosen.

The Charleston area is particularly threatened by intensifying flooding brought on by climate change. The warming atmosphere is creating more intense hurricanes and heavy, torrential rain storms. Meanwhile, the sea level around Charleston already has risen by more than a foot over the past century, and global warming may add another 3 to 6 feet by 2100. 

Not only will that lead to more tidal flooding even on sunny days, higher seas will make hurricanes' storm surge more destructive and more capable of reaching farther inland. 

One study by the Union of Concerned Scientists earlier this year predicted that 22 percent of homes on the lower half of the peninsula would repeatedly flood if the sea level rises 2 feet by 2045.

Large-scale drainage projects underway on the peninsula are expected to help prevent flooding during typical rain storms, but those systems aren't equipped to shield the area from the more destructive threat of storm surge. 

"Storm surge events are one of the major areas of concern and events of flooding from extreme precipitation," Wilbert said. 

The infrastructure capable of protecting the peninsula from those threats is very expensive, and probably couldn't be funded without federal help.

After Hurricane Katrina devastated New Orleans, it took cooperation from all levels of government to build the $20 billion system of levees, sea walls and pumps that now protect the historic city.

One of the first steps in that process was an Army Corps study.

The Battery offers some surge protection along the southern edge of the peninsula. A $100 million project is underway to raise the lower half by 2½ feet, which would make it about the same height as the High Battery. 

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Reach Abigail Darlington at 843-937-5906 and follow her on Twitter @A_Big_Gail.

Abigail Darlington is a local government reporter focusing primarily on the City of Charleston. She previously covered local arts & entertainment, technology, innovation, tourism and retail for the Post and Courier.

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