Between the Departements of Calvados and Manche

Here the river Vire is the boundary between the two Departements, both of which belong to the Region of Lower Normandy. Calvados is to the left, Manche to the right.

Beneath this bridge on the D124 road are five portes à flots, using massive wooden gates to keep the salt water of the English Channel out of the inland waterways.

The river water flows towards bottom left, and so long as it is higher than the sea's level the gates will remain open. Once the pressure exerted by the sea water is stronger than the river flow, that pressure will cause the gates to close. This means that the gates will usually open and close with the tides, but as long as the river is abnormally high the gates will stay open.

Simple but clever technology, and of great importance to the ecosystem.


Photo added in February 2014