Between 2009 and 2011, the « J’y mets mon grain de sable » project, a vast dune reinforcement project aimed at mitigating the erosion of low sandy coasts in the most sensitive areas of the archipelago, was carried out by the Attention FragÎles team in collaboration with various partners. The project also helped to create the first overview of dune erosion on the Islands’ beaches.
Four methods were used to trap the sand and rebuild the dune: building weirs and sand fences, planting American marram grass, and adding groundcover plants. Groups of citizens and schoolchildren were mobilized for this project. In 2009-2010, 82 sites were restored with the help of 225 people, with an additional 107 sites in 2010-2011, thanks to 144 participants. Finally, six interpretation panels were installed near the beaches to promote the sites rebuilt by the community and invite visitors and locals to take care of the dunes. The brochure "Fighting erosion together," produced in 2010, was also distributed to the participants. In 2011-2012, a follow-up of these restorations was carried out, 105 project sites were visited, and a report on the success of restoration in the dune environment was drawn up.
This report showed that from the first year of installation, we observed a rise in the level of sand of more than 30 cm on the structures in about 80% of cases. After two years of operation, it was possible to observe a burial of the structures to a height of 50 to 70 cm in more than 60% of the restored sites. This report has therefore highlighted the effectiveness of sand traps with a view to dune restoration.
