In the face of increasing beach and dune erosion, the community of Quend-Plage, located on the Picardy coast of northern France, installed a beach drainage system in 2008. As a result of this, the macrotidal beach of Quend-Plage has been stabilized, preserving both natural habitats and recreational spaces.
Based on: Bain, Olivier, Renaud Toulec, Anne Combaud, Guillaume Villemagne, and Pascal Barrier. "Five Years of Beach Drainage Survey on a Macrotidal Beach (Quend-Plage, Northern France)." Comptes Rendus Geoscience 348.6 (2016): 411-21. Web.
The Quend-Plage beach is characterized by a mix of transverse bars and troughs along the tidal flat. The wider coastal region is subject to the influence of both waves and tides, and by contrasting temperate and oceanic climates.
The implementation of a beach drainage system had never been used in the north of France, despite being tested elsewhere in Europe and overseas. The system was placed in the upper tidal flat of the beach, and consists of a drainage pathway 5 m wide, 900 m long, and 1.5 m deep. The system is susceptible to damage from storms and can malfunction over time, requiring maintenance.
Tourism plays a large role in the local economy of the Picardy coast. With hundreds of thousands of visitors per year, much of the coast is dominated by the tourism industry including Quend-Plage beach. Mussel farming and sea animal harvesting are also important to the local fishing economy.
After several years of beach erosion, and degradation of the existing sea wall, Quend-Plage beach lost much of its dry sand and recreational activities moved inland toward the dunes, which increased erosion of the dune foot and reduced tourism income. In response, the community of Quend-Plage invested in researching various coastal protection strategies, and the implementation of a beach drainage system was chosen.
Funding was received by European and national funds. The French government authority “Direction départementale des territories et de la mer” later requested a five-year long monitoring survey be undertaken to determine the effectiveness of the largely experimental technique for that region of France.
Exploring a new technique
One of the reasons why a beach drainage system solution to coastal erosion was selected by the Quend-Plage authorities was because it had never been done before in northern France and on the Picardy coastline. This was an opportunity to explore a new technique that, if successful, could be replicated along the coastline where deemed appropriate. The initiation of an extensive 5-year monitoring program, considering topographic, geomorphic, and granulometric factors, by the French “Direction départementale des territories et de la mer” indicates the experimental focus of the project and the commitment for long-term solutions.
The use of a beach drainage system to combat coastal erosion along the Picardy coastline is a feasible and effective solution. In the case Quend-Plage, the beach morphology was significantly altered in the first five years after the system was installed. The upper beach and foot of the dunes recovered and increased in size. However, there was some erosion of the middle and lower beach and a small directional change of the bars and troughs. Overall, the drainage system facilitated a complete re-establishment of the Quend-Plage beach features, which ultimately brought more stability and usability to the community