Boskalis protects vulnerable coastline in Benin and Togo – Sand Engine Concept

Technology

Due to the ongoing sea level rise, the coastline of Togo and Benin in West Africa is eroding by more than two meters every year. The result: houses literally end up in the ocean and the local population – which lives largely from fishing and arable farming – is struggling to make a living.

Boskalis

To call a halt to this erosion, Boskalis is protecting this vulnerable coastline over a length of 40 kilometers by placing and reinforcing breakwaters, but also by constructing a sand engine in Benin.

The sand engine concept was co-developed by Boskalis and has been successfully applied in the Netherlands over the past decade.

Boskalis photo

Around 6.4 million cubic meters of sand is currently being deposited at a strategic location and, over time, the natural motion of wind, waves and currents will spread it eastwards along the coastline.

This principle of building with nature will reinforce the coast in a robust and natural way.

“It is a great natural solution to a major problem facing society in this region. A prime example of Building with Nature,” said project director Frans Thomassen.

“We will take steps to shape the beach in such a way that fishermen and arable farmers will no longer be under threat in the coming decades and that their homes will be preserved and not filled with sand.”

Boskalis photo

The construction of the sand motor has already started.

Thomassen added: “During that construction, we want to return a section of beach of about 300 meters to the local people every week so that they can resume their daily activities as quickly as possible and enjoy the benefits of the coast again. That gives them a living and, in this way, we minimize the social impact of our work as much as possible.”

Boskalis photo

“That impact was measured prior to the project in an Environmental and Social Impact study,” said Boskalis’ desk manager Kevin Swinkels.

“We looked at housing the local population elsewhere temporarily but also at possible compensation for the temporary loss of income during the work. Everything has been sorted out properly now.”

And so Boskalis will be working through to late 2023 to protect about 40 kilometers of the West African coast.