NOVA | Sinking City of Venice | See the Gates in Action (QuickTime)

See the Gates in Action

Venice homepage

For three decades, a single idea on how to safeguard Venice and its lagoon from sinking beneath the sea has held sway: a wall of hinged barriers at each of the three entrances to the lagoon that would rise at the flick of a switch to collectively block extreme high tides from entering the lagoon. Sounds simple, right? Well, it is, after a fashion. Below, watch an animated movie and see how the mobile gates would work. For more on the gates proposal, including its history and current status, see Weighing the Solutions.

See an illustrated transcript of the video narration

Type of gate: disappearing oscillating buoyancy flap gate

Number of gates: 4 rows at three locations (Lido, 2 rows; Malamocco, 1 row; Chioggia, 1 row)

Number of individual gate sections: 79 (Lido, 41; Malamocco, 20; Chioggia, 18)

Individual gate dimensions: 66 feet wide, 15.5 feet thick, 99 feet long at deepest point

Weight of each gate: 250 - 350 tons

Height of tides when gates operate: 40 inches or more above average

Average lagoon inlet closure time: 4.5 hours

Time necessary to open the gates: 30 minutes

Time necessary to close the gates: 15 minutes

Maximum difference in level between sea and lagoon when gates are raised: 6.6 feet

Cost of the project: $1.9 billion

Project execution time: 8 years

Number of direct jobs during execution: 1,000 per year

Number of direct jobs when fully operational: 150 per year

Maintenance and management costs: $9.2 million per year ($6.2 million for maintenance, $3 million for management)