Enclosing dyke in the port of Brest

To support the development of marine renewable energies, the Port of Brest has undertaken the construction of a new terminal dedicated to the handling of goods related to their operation.

Several worksites have been launched, including that of the enclosing dyke, the first stage in the creation of a new 14-hectare polder that will house part of the facilities.

This contract, awarded to Bouygues Travaux Publics Régions France, involves the construction of an 890-metre-long arched dyke to close off an “enclosure” where the marine sediments dredged from the port will be stored, in other words 1.25 million m³ of sediment.

The breakwater consists of 26 circular cofferdams and 25 festoons made of flat sheet piles 21 to 33 metres long. This solution was preferred to a sloped breakwater because it allows for greater sediment storage. The breakwater also incorporates eco-reefs that retain water at low tide to preserve ecosystems.