Jan De Nul Designs Submerged Dike for Benin
Jan de Nul Group has designed a submerged dike that will protect the Beninese coastal villages Avlékété and Djégbadji, part of the town called Ouidah, against the impact of the Atlantic Ocean.
The Beninese Ministry of Living Environment and Sustainable Development has now kicked off the coastal protection works with the first stone installation executed by the side stone installation vessel Pompeï, near Avlékété.
The coast of Benin is highly susceptible to erosion due to its geographical situation along the Atlantic Ocean. The erosion of the beaches is further enhanced by the construction of paved dikes on land. Consequently, coastal tourism cannot develop in this area. For that reason, the Government makes an extra effort in its Government Action Programme to protect the Beninese coast.
Wave Damping Effect
Jan De Nul Group's design is a submerged dike at about 150 m off the coast. The dike has a wave damping effect, which means that the waves of the Atlantic Ocean are broken before they reach the coast. A wave-free climate develops between the submerged dike and the coast. This will significantly reduce the impact on the beaches, as a result of which the sand will move less and erosion will decrease.
Because the dike is submerged, the view of the horizon will not be disturbed. From the beginning, Jan De Nul Group has worked on maintaining that aesthetic character, which is very important in the context of the government plans to fully develop coastal tourism in Benin.
Stone Installation and Beach Regeneration
The works started in February 2018. Granite rock from national and international quarries was transported to the site. Stone installation works are now underway. In a first phase, a submerged dike of 2 km will be installed. Another two rock installation campaigns of 2 km each will follow, one in Avlékété and another in Djégbadji.
After the installation of the submerged dikes, Trailing Suction Hopper Dredgers of Jan De Nul will dredge and reclaim sand to restore the affected beaches. Works will be completed in 2021.