Environment

The hydro-sedimentary impact

The port extension in the open sea questioned about potential impacts on currents, waves, sediment transport and changes in the seabed and coastline morphology. Numerical simulations enabled to appreciate the consequences on the development of coastal and marine living spaces and coastal risks (withdrawal of the coastline and marine submersion). The breakdown profile was then optimized to substantially reduce these impacts.

Furthermore the breakwater and piers were enhanced to 1.5 m compared with the existing port taking into account the worst predictions of rising sea levels in the next 100 years.

The ecological issues

The land and sea areas impacted by the project, the potential nuisances of the work site such as land and underwater noise, dredging, and of future operations are all factors that may affect directly or indirectly the ecological issues in close proximity (life in dunes, protected flora, birds frequenting the port and its surroundings, seal colony, “Natura 2000” living spaces and species …). A comprehensive inventory of the wildlife fauna, flora and living spaces has been conducted on more than a year to accurately characterize these issues and take them into account in the design with adapted construction methods, quiet areas for birds, eco living space for marine wildlife.

The living environment

Areas close to the port and its transport infrastructure are particularly sensitive to noise pollution and air quality. Acoustic measures and simulations and expertise studies on air quality were conducted to assess the consequences of the increase in road and rail traffic, but also the part of the maritime traffic far away in the new basin.

 

Following the Public Inquiry, some mitigation and compensation or support measures were decided, the most significant are :

Mitigation measures : 

• Adjusting the site plan to reduce hydro-sedimentary impacts, dredging requirements and the occupation of the dune with protected species.
• Precise phasing of the work in time and space to limit the disturbance of marine mammals and seabirds in close proximity (breastfeeding period, nesting).
• Preservation of favorable areas for bird nesting on port platforms during the construction and operations of the future port.
• Moving heritage plant species growing in the site area.
• Setting up a lighting plan designed to limit light pollution.
• Measures to ensure environmental practices during construction.
• ​​Construction and energy consumption (environmental performance of buildings).

Compensation measures :

• Preservation.
• Restoration.
• ​Ecological management of a compensation site of about 20 hectares with high ecological potential in the immediate vicinity of the construction site.

 Support : 

• Monitoring the quality of coastal waters (over 5 years).
• Scientific monitoring of species (over 15 years).
• Observation site for migratory and wintering birds on the future pier.
• Ecological management of undeveloped port area.
• Monitoring the air quality (modeling and station).
• ​Control the sound close to sensitive areas.