Coastline and port infrastructure protection in Charente-Maritime (France)

Planning, reconstruction and renewal of coastline protection devices and port infrastructure projects in Charente-Maritime

Project date: 2012-2015
Location: France
Reference: 12900

Description of the Contract

When Storm Xynthia struck on 28 February 2010, the combination of an oversize high spring tide and a strong swell from violent winds led to severe flooding all along the Charente-Maritime coastline.

Many structures in the Charente-Maritime department were severely affected by this flooding, revealing the weakness of the defence structures against the sea.

Initial emergency work was followed by overall discussion at all institutional levels, stating the need to restore the damaged structures on the one hand but also to review risk levels and readjust the entire coastline protection.

Within the perspective of longer-lasting work, the Charente-Maritime Departmental Council (CG17) therefore decided to provide technical support to local authorities affected by areas that are particularly sensitive to submersion, by getting a set of studies done that were necessary to define and perform the projected planning.

KERAN (formerly SCE group), through its companies SCE and CREOCEAN, was appointed within a framework agreement to carry out this vast "planning and reconstruction operation or renewal of coastline and port infrastructure protection" on all the sensitive areas in the department. The aim is to provide long term planning for inshore areas taking into account new protection aims regarding marine submersion hazards.

Services provided

The CREOCEAN and SCE teams made their expertise available to the Departmental Council to run assignments on:

  • Port infrastructures,
  • Road structure and civil engineering,
  • Hydrodynamic and hydro-sediment appraisals,
  • Hydraulic appraisals,
  • Water Act case file, Natura 2000, Flora/Fauna appraisal,
  • Urban studies and territory strategy...

Several operations are already under way:

  • Securing the Saint Clément/Doreaux western seawalls: study modelling hydrodynamic conditions, study defining protection scenarios, regulation studies (impact study, water law study)
  • The marsh embankment in the village of Yves: modelling hydrodynamic conditions, protection scenario definition study, regulatory files (water act, public survey, Natura 2000, etc.)
  • Securing the La Flotte en Ré port: diagnosis on structures, ports, project studies to raise the protection structures, regulatory studies (commission of sites, danger studies, impact study...)
  • Securing the Tridoux and Saillant sectors on the Aix Island: hydrodynamic condition modelling studies, technical studies (Pre-Project/Project), environmental and regulatory studies to define the sea defences
  • Complementary study on risks of submersion over the Boyardville area: technical studies prior to defining sea defences with submersion phenomenon modelling
  • La Cotinière Port: Summary of environmental alarms followed by Project Ownership support during tender dialogue
  • Oléron south east coastline: modelling, danger study, Water Act incidence, dispensation case file for destruction of protected species, Natura 2000 case file, case file to present to the site commission (PAPI Oléron)
  • Diagnosis of protection structures for Ormeaux and Coudepont and Diagnosis for the Jeamblet breakwater on the Aix Island

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