In order to improve knowledge of the risk of flooding due to rainwater run-off in the Montpellier Mediterranean Metropolis area, the aim of this project is to model flood-prone areas throughout the region.

It enables flood-prone areas to be characterised, flood hazards to be mapped and development solutions to be proposed. The results will be used to prepare the PLUi*, crisis management and vulnerability reduction. The study covers 860 km of hydrographic network, in both urban and natural environments. The 2D hydrological and hydraulic modelling is carried out by applying rainfall to the natural terrain survey and utilising high-definition LIDAR data (IGN). A detailed sensitivity analysis is conducted on test areas (grids, buildings, and small walls). The results will then be used to support crisis management.

*plui: intermunicipal local urban planning plan

The project consists in constructing a toll way that doubles up the existing congested A9 freeway over 19km near Montpellier. The main characteristics are:

• 3 lane divided carriageway running parallel to the existing A9 freeway over 10 km at the eastern and western ends of the project and running parallel to the proposed high-speed railway line over 8km,
• 1 system interchange at each end of the project with widening of the existing freeway (over 4km at each end),
• upgrade of Vendargues interchange,
• grade separation of local roads,
• rest areas,
• modification of the existing tell facilities.

The contract comprises designing and constructing the proposed toll way.

Additional services include: assistance to ASF with public consultation, project management, etc.