Coastal Erosion Mitigation in Saint-Louis, Senegal: Evaluating the Effectiveness of “Typhavelles”, a Nature-Based Solution

Coastal erosion poses a major threat to low-elevation coastal zones such as Saint-Louis in Senegal, where rapid shoreline retreat has led to community displacement and infrastructure degradation. To address this challenge, nature-based solutions (NbS) have been deployed within the Saint-Louis Marine Protected Area (MPA), notably the installation of “Typhavelles” structures made from Typha australis designed to promote dune formation and reduce erosion. This study assesses the effectiveness of “Typhavelles” using field data collected from 2019 to 2022, complemented by diachronic satellite imagery analysis. Results indicate a notable increase in beach width and dune development across the majority of monitored profiles. Shoreline change analysis reveals a dramatic shift from severe erosion (up to −94.5 m/year between 2017 and 2019) to significant accretion, reaching up to +136 m/year during the 2019-2021 period following the installation of the “Typhavelles”. These findings demonstrate that “Typhavelles” are effective in trapping sediment and stabilizing the coastline. However, their long-term viability may be compromised by sea level rise, sediment supply limitations, maintenance needs, and material biodegradation. The study highlights the promise of bio-inspired NbS for coastal protection and recommends enhancing “Typhavelles” durability through protective treatments to support broader replication in similar vulnerable coastal zones.