NGE, in a joint venture with Charier and CDES, will deliver one of the largest river construction projects in France.

NGE TMF, a subsidiary created in 2023, is working on this project alongside entities from the GUINTOLI Group and NGE PAYSAGES, in a joint venture with CHARIER (lead contractor) and CDES, under the project management of EGIS and CNR. This is one of the largest river construction projects currently underway in France, both in terms of revenue and the material and human resources deployed.

The works are located in the Loire and on the banks on the right and left bank of the river upstream of the Bellevue bridge, as well as in the Thouaré branch, in the municipalities of Sainte-Luce-sur-Loire, Basse Goulaine and Saint-Julien-de-Concelles.

They consist of the construction of a submerged rockfill dike, called "Duis", and its related facilities.

The development of the Bellevue culvert creates a head loss, reducing the hydraulic gradients upstream of the structure and promoting the gradual deposition of sediments. The overall objective of the program, outlined in the first Loire Grandeur Nature Plan of 1994, is the restoration of the morphological balance of the Loire's minor channel and its associated ecological functions.

These structures are being built entirely using nautical methods to minimize disruption and take into account the specific constraints of the project's environment. This is a major undertaking for NGE TMF, NGE's subsidiary specializing in maritime and river works, marking a significant milestone.

A significant amount of equipment has been deployed to enable the launch of hydraulic dredging operations, the river transport of materials by barges, and the establishment of five floating workshops with excavators and cranes on pontoons that operate simultaneously. At the peak of activity during the summer and autumn seasons, more than twenty floating units are mobilized by the Group.

The operations were scheduled over 2 separate periods in 2024 and 2025, timed to take into account environmental constraints regarding fauna and flora, with work taking place between July and November, during which the river flows are also the most suitable for this type of intervention.

Year 1 allowed for the completion of the first preparation work on the bottom and related work to protect the banks on the right and left banks, the dissipation mat and the removal of existing rock spurs.

The start of year 2, focused on the completion of the main structure of the Duis, has been entirely satisfactory and the work will be completed at the end of November.

To ensure the work is carried out, NGE TMF has initiated a dynamic policy of recruiting personnel specializing in nautical earthworks and dredging techniques, as well as investing in new equipment, including the acquisition of a high-capacity suction dredger.

Two years after its creation, NGE's specialized subsidiary has doubled its turnover and workforce. Among its recent projects are the work on Quays P4-5 and P10-11 in Port la Nouvelle, the construction of two fish passes on the Rhône in Lyon and Beaucaire, and the reinforcement of the banks of the Garonne lateral canal as part of the North Toulouse Rail Development.

Key data from the construction site

• 23 M € turnover
• 10 months of work over 2 seasons
• 170.000 m3 of materials used (filter layers and riprap)
• 1 vacuum cleaner dredge
• 4 mechanical dredging pontoons with onboard long-arm excavators
• 1 pile-driving pontoon with onboard lattice boom crane
• 1 amphibious excavator mounted on floating caissons
• 4 material transport pontoons
• 3 split flap-type barges
• 4 pushboats and 5 service boats
• 1 conveyor belt for transporting filter layer materials
• 1 loader, 3 dump trucks and 2 excavators with grapples for on-ground work involving the supply and loading of riprap