The barriers are created at the three gates of the coastal cordon through which the tide enters the lagoon:
- 2 in Lido (21 + 20 sluice gates) given the width of this harbor inlet and the presence of two channels with different depths
- 1 in Malamocco (19 sluice gates)
- 1 in Chioggia (18 sluice gates).
The inactive flap gates remain full of water and completely invisible in their housings in the seabed of the mouth channels.
In the event of high tide, compressed air is introduced into the flap gates to empty them of the water. As the water comes out (in total 30 minutes), the flap gates, rotating around the axis of the hinges, rise up to emerge and block the flow of the tide entering the lagoon.
When the tide falls, the flap gates are again filled with water and return to their home (in 15 minutes), without interfering with the exchange of water between the sea and the lagoon.