The wind was stirring up the sea around Venice, Italy, threatening to raise the tide to 4 feet — a level that's at least 1 foot above normal. In the past, that would be enough to inundate half the city, leaving tourists to trudge through knee-high floodwater in St. Mark’s Square. But this wasn’t a normal day.
On this rainy Saturday in early October, for the first time, officials would make use of MOSE, a system of movable sea barriers built to protect Venice against floods.
Venice sits in the middle of an enclosed bay with only three entrances. To guard those entrances, engineers came up with MOSE, which stands for Modulo Sperimentale Elettromeccanico, or Electromechanical Experimental Module in English. Mose, incidentally, is also the Italian word for "Moses" — the biblical figure who parted the Red Sea.
The system consists of 78 panels that lie flat on the seafloor. At 8:30 a.m. on Oct. 3, those panels filled with air, causing them to swing upright like cellar doors being thrown open. Shortly thereafter, the Venice Lagoon was separated from the Adriatic sea by three bright-yellow sea walls.
