The MTA shut down a part of the Brooklyn-Battery Tunnel Thursday night to test flooding prevention measures as part of ongoing hurricane contingency planning after Sandy.
NBC 4 New York got an exclusive look as workers tested 85-foot-long inflatable dams at the tunnel. The tubes, which cost $90,000 each, fill with water from fire hydrants and rise to 4 feet high. The dams can block 3 feet of floodwater.
Romolo DeSantis, who's in charge of post-Sandy projects at the Battery Tunnel, calls the dams a rapid mitigation measure. Three dams would be used to protect the openings of the tunnel in case of hurricane flooding.
DeSantis said it would take about an hour to pump 20,000 gallons of water into one of the inflatable dams.
"Quicker than sandbags, the quickest effective measure," he said.
Sixty million gallons of water flooded the tubes of the Battery Tunnel during Sandy, shutting down the vital commuter connection for weeks. With this year's hurricane season lasting for another two months, the MTA is working urgently to figure out fixes at flood-prone areas.
"Nearly two-thirds of the tubes completely flooded," DeSantis recalled of Sandy, adding the water went up 65 feet in one of the ventilation shafts.
The MTA has already built a plywood wall on one side of the tunnel where the floodwaters rushed in.
The tunnel connects south Brooklyn and the Wall Street area, and is the longest vehicular under-river crossing in North America.