Sustainable development of the Somme bay

Development and implementation of a strategy to protect a region highly exposed to flooding and submersion

The Syndicat Mixte Baie de Somme – Grand Littoral Picard initiates and manages various developments, combining environmental and socio-economic targets, in a region covering more than 100 km of coastline with a relatively diversified morphology (bays, estuaries, beaches, cliffs, etc.).

Since 2013, Artelia has been working with the Syndicat to draw up and then implement a Flood Prevention and Action Programme (PAPI Bresle-Somme-Authie), aimed to protect the region against extreme climatic events.


Since the early 90s, Artelia has been carrying out studies in the Somme bay on issues such as silting up, flood protection, reinforcement of the coastline, de-siltation, etc.

In 2010, following the Atlantic storm Xynthia, which caused around fifty deaths and serious damage to property, the French government and local authorities implemented Flood Prevention and Action programmes (PAPI) to identify vulnerabilities and implement solutions to reduce the risks and impacts of this kind of extreme events.

Artelia was actively involved in drawing up the PAPI, covering three estuaries (Bresle, Somme and Authie) and the river Somme and its associated tributaries. This process has enabled us to draw up a comprehensive summary of the problems facing the area and a detailed assessment of the stakes involved, including technical and environmental aspects as well as economic and social standpoints.

A complex numerical model, covering both river and maritime domains, was built that gives a better understanding of the phenomena at work, enabled the risks to be assessed according to different climatic events, and helped to define the measures needed to combat river and coastal flooding. In 2020, the client awarded our teams the provide project design and construction supervision services for the works planned in the context of the PAPI, covering some thirty highly varied measures, including raising breakwaters, protection against coastal erosion, seafront development and beach recharging.

Photo credits: Altimage