In Cotonou, the capital of Benin (West Africa), up to thirteen meters of shoreline disappeared each year due to erosion, causing serious consequences for the densely populated coastal area. The relentless retreat of the coast eventually reached inhabited neighborhoods of the city, with erosion swallowing dozens of houses, hotels, tourist centers, and other structures annually.

In 2003, the Government of Benin commissioned studies, which concluded that protective structures needed to be built along a seven-kilometer stretch.

The expertise of Norda Stelo in coastal engineering was commissioned by the Ministère de l’Urbanisme, de l’Habitat et de l’Assainissement du Bénin to conduct engineering studies and construct eight groynes along a seven-kilometer stretch of coastline to address the significant issue of shoreline erosion.

The groynes, made of concrete blocks and crushed stones, span a total length of 2,445 meters. They help counter the force of ocean waves and prevent sand erosion. More than 500,000 metric tons of rock, sourced from three quarries located over 250 kilometers from the project site, were used. The establishment of a concrete plant for the production of molded X-blocks generated significant local employment. In addition to halting coastal erosion, the groyne structures have enhanced the safety of coastal residents and ensured the sustainability of their economic activities.

Training local personnel in coastal engineering methods and techniques helped develop local expertise, enabling ongoing collaboration and monitoring post-construction.

An environmental management plan was also implemented to protect terrestrial and marine habitats, which are vital resources for tourism and fishing.

Norda Stelo assembled and trained a team of 20 Beninese engineers and technicians in coastal engineering to carry out this large-scale project aimed at halting coastal erosion, ensuring the safety of residents in the coastal area, and sustaining their economic activities. This initiative led to the revival of local businesses, the preservation of hotel complexes, and the continuation of residential development.

This mandate highlighted the rapid progression of coastal degradation, the complexity of the challenges it presents, and the necessity for Beninese authorities to develop local expertise to closely monitor shoreline erosion. Over time, Canadian experts took on an advisory and oversight role, facilitating the continued sharing of best practices in marine and coastal engineering.

The coastal protection project in Benin stands as a major success for Quebec, clearly demonstrating how engineering contributes to the implementation of sustainable solutions that address climate change challenges while ensuring social acceptability.

• Curbing the process of coastal erosion
• Preservation of valuable marine resources
• The role of artificial reef currently fulfilled by the installed groynes, enabling the establishment of algae and marine invertebrates
• Training of Beninese engineers and technicians in coastal protection
• Use of numerical modeling to analyze water movement and design effective groynes
• Implementation of mitigation measures to minimize disruptions and ensure safety during construction
• Need for strict oversight and coordination between the quarry and the construction site
• Establishment of a concrete plant, generating significant local employment
• Completion of the project within budget and four months ahead of schedule

• Environment, Climate change and Community
• Ports and Coastal
• Structure
• Civil Engineering Works
• Health and Safety