France – Highways engineering services – Etudes approfondies de vulnérabilité du réseau autoroutier COFIROUTE aux risques crue et inondation

The contract concerns the conduct of vulnerability studies of the motorway infrastructure and its structures to flood and inundation risks, over approximately 118 km of the COFIROUTE network divided into twelve study zones. The services include the conduct of hydrological and hydraulic modelling, and engineering missions at the "diagnostic" and "preliminary study" levels of solutions for adapting to limit the impacts of floods and inundations on the motorway infrastructure, as well as the management of ancillary services contributing to the conduct of the vulnerability study. The present contract is divided into twelve (12) technically homogeneous geographical zones. The present contract is divided into five (5) lots grouping these 12 zones as follows: • Lot No. 1: A10 — Loire Valley tributaries: South Orléans, Brenne, Saint-Laurent (zones 1 to 3) • Lot No. 2: A10 — Vienne & Clain: Sainte-Maure → Poitiers (zones 4 and 5) • Lot No. 3: A28 south — Loir & Huisne (zones 6 and 7) • Lot No. 4: A28 north / A81 — Maine basin: Sarthe, Vègre, Mayenne (zones 8 to 10) • Lot No. 5: A11 & A71 sites — Gourville, Yèvre / Barangeon (zones 11 and 12) For each lot, the services are carried out in the following stages, without a preliminary screening stage: Firm Section: • Stage 1 — Initialisation: data appropriation, field visits to each of the watercourses, establishment of the pluviometric and hydrological reference, framing meeting; • Additional topographic and bathymetric surveys: definition of needs and drafting of the consultation specification for surveyors, then follow-up of the services and receipt of the data; • Stage 2 — Detailed hydraulic modelling of the watercourses in the zone, characterising heights, speeds and durations of submersion at every point; Optional Section: • Stage 3 — Technical feasibility at the preliminary study (EP) level of adaptation solutions; • Associated services: ecological pre-diagnosis and land analysis.