RED HOOK — A semi-permanent flood barrier started rising Monday along Red Hook's lowest-lying street — but it sits below where Hurricane Sandy left its high-water mark almost five years ago.
The flood wall now under construction, called a Hesco barrier, is made of sturdy green fabric that will be filled in with dirt. It stretches along Beard Street from Van Brunt Street to the IKEA property line just past Richards Street.
The 4-foot wall would protect the neighborhood from a mild coastal storm surge, but nothing like the impacts of a 100-year flood, which city forecasters say would bring 10.2 feet of water to the intersection of Beard and Richards streets.
"If it was a Sandy-level storm, it would not protect it," Jessica Colon, a senior policy advisor for the Mayor's Office of Recovery and Resiliency, said at a June public meeting about the project.
To prevent flooding from another storm like Sandy, the wall would have to be about 16 feet high, an unlikely option for Red Hook, Colon said at the meeting.
In planning terms, a 10-year flood means the area has a 10 percent chance of flooding in any given year. A 100-year flood means there's only a 1 percent chance of it happening any given year. Sandy was considered a 100-year flood.
Additionally, there will be three gaps in the Hesco barrier to accommodate existing driveways, said Rachel Finkelstein, spokeswoman in the Mayor's Office for Climate Policy and Programs. If a storm surge is in the forecast, those gaps will be filled last minute with "Tiger Dams" — or "water-filled tubes that get installed and inflated when a storm with potential coastal storm surge is forecasted," Finkelstein said in an email Tuesday.
The Hesco barriers along Beard Street "should be fully installed by the end of this week," she said.