Dealing with the vagaries of the weather and the sea
The Communauté de Communes Coutances Mer et Bocage (CMB) is an area with many challenges, particularly environmental and economic (shellfish and aquaculture, livestock farming on salt marshes, tourism, etc.). This area is weakened by the combination of several factors:
The vagaries of coastal erosion and marine submergence, exacerbated by the rise in sea levels,
hydraulic and hydrogeological risks (river flooding, rising groundwater levels, etc.), exacerbated by climate change.
The coastal strategy has identified the risk of breakwaters forming on the northern and southern spurs of the port of Blainville, exposing shellfish beds protected by narrow dune ridges to the sea.
The entire coastal area has been the subject of more or less successful attempts to protect the coastline, ranging from the installation of "big bags" filled with sand and wrapped in an unsightly geotextile, to the emergency installation of rip-rap, including geotubes also filled with sand and installed at the foot of the dune, wooden or geotextile groynes, rows of hydraulic piles, fascine mattresses or even sand replenishment.
In 2019, the sustainable coastal management strategy for the western Cotentin coast recommends anticipating the retreat of the most endangered sites in Gouville-sur-Mer and creating a model for coastal recomposition based on a shellfish farm, such as the one in the port of Blainville.
In order to preserve the areas vulnerable to the identified risks, the reconstruction of the coastline has been at the heart of the CC CMB's regional project for several years, such as the PAPI (2017) 'Côte des Havres' (watershed between the ports of Regnéville in the north and Vanlée in the south).
In line with the commitments already made by the CMB (Action Programme for Flood Prevention PAPI 2017, ecological transiti