Feasibility study for a coastal-flooding and erosion forecasting system in the Hauts-de-France region

The need

In 2021, the Pôle Métropolitain de la Côte d'Opale (PMCO, Regional Metropolitan Council of the Opal Coast) asked BRGM to carry out an analysis of existing state-of-the-art technology for local Coastal-Flooding and Erosion Forecasting and Warning Systems (SPASE) and the possibility of applying these systems along the Opal Coast and Picardy Coast (which has a coastline of 200 km) in order to anticipate coastal flooding and erosion events 3 to 5 days before they occur. The study aimed to assess the extent to which and how the most recent applied research technologies could be used to set up an operational system that meets the objectives and constraints of the PMCO.

The results

Following bibliographic research and surveys carried out among PMCO's partners, the final system proposed is based on four modules:

1. A very-high-resolution wave and sea-level forecasting system in coastal areas,
2. The implementation of impact indicators on the region's coastal segments,
3. The implementation of local coastal-flooding models to estimate the size of the areas subject to a risk of coastal flooding,
4. Real-time video surveillance of certain sites.

In addition to the technical solutions, BRGM also analysed the implications of the system in terms of governance and responsibility for PMCO and its partners, as well as the most appropriate economic model. Various forms of governance were therefore proposed. The preferred solution will require an organisational structure based on a partnership project, managed by the PMCO, with agreements concluded with public partners on a case-by-case basis, and a service provider to be selected through a call for tenders.