Summer 2014

A reef of geosynthetics

The famous beaches of the Bay of La Croisette in the French coastal city of Cannes are discreetly protected against the pounding of waves and storms. The solution consists of a reef in the form of a submerged breakwater of TenCate Geotube® containers. The work was completed quickly and without any noticeable impact on the environment or the pleasures of beach and water. 

The French Mediterranean coast is regularly battered by heavy seas and storms, with waves more than 5 m high and wind speeds of over 100 km an hour. In recent years these extreme weather conditions have led to severe damage to restaurants and beach facilities. To limit future damage and its economic impact, the city of Cannes decided to protect the well-known beaches of La Croisette by constructing a submerged breakwater of sand only. This solution was to have no negative effect on the view from the beach; furthermore impact on the activities of sunbathers and swimmers and on the environment was to be kept to a minimum. 

geosynthetics cannes golfslag
Bay de la Croisette

The breakwater consists of two rows of TenCate Geotube® containers that were hydraulically filled with sand. They rest on a 20-m-wide geotextile mat, whose function is to prevent scour under the tubes. This scour-protection mat is fixed on both sides by a ballast system in the form of small tubes of 50 cm diameter. The construction itself is 10 m wide and is located between 80 and 100 m from the shore at a depth of 3 to 4 m. This is approximately 1 m below the surface of the water. The containers have a diameter of 4 m and vary in length from 25 to 30 m. The total length of the submerged breakwater is 545 m. It is divided into four sections and between each section there is a navigation channel for small ships.

geosynthetics cannes geotube 2
Work in progress

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The project has been regularly monitored both during and after construction, and these inspections have showed that the marine life has very quickly re-established itself. 

geosynthetics cannes geotube onder water gereed

Already the initial dark colour of the TenCate Geotube® containers has largely disappeared as a result of the development of flora such as sea grass.

Blue fabric (Tecawork Blue 65287)