PROTECTING THE NATURAL ENVIRONMENT OF THE NEW COAST ROUTE
The exemplary nature of the New Coast Road project in Reunion. A single brief: to control the risk to surrounding environments
The project’s environmental approach is based on four fundamental pillars:
1 – The definition of requirements
2 – The implementation of resources
3 – Performance obligations set out in works contracts
4 – Monitoring and follow-up
Environmental monitoring at all levels
- Egis (project manager) will ensure the compliance and effectiveness of measures implemented by its companies.
- On-site, the companies’ environmental managers will ensure good environmental practice on a daily basis.
- Biotope, the environmental consultant, will visit the construction sites on behalf of the Region at least twice a month.
- The operating department of the New Coast Road centralises and analyses the different environmental data and informs government departments.
- The government’s environment services can carry out unannounced and regular checks at their convenience.
- At least twice a year, the Region presents an environmental assessment to the project’s technical committee, which includes representatives of the government and local authorities concerned.
A scientific committee, made up of experts, is consulted as required on the various environmental aspects of the project.
- An important system has been implemented to control underwater noise and its effects on mammals, particularly on the site of the D1 breakwater, near Saint-Denis. “After thorough studies at the cutting-edge of our field, we determined the optimal conditions for undertaking the work with regard to the sensitivity of the environments, the species and their habitats, which were studied over full biological cycles (a year of inventories and specific studies) and established a detailed eco-design of the works” explain Laure Camelin and Céline De Plasse, successive managers of environmental monitoring for the New Coast Road site for Egis. “Before each phase of noisy work, we made sure that there were no cetaceans in the zone of influence, which is monitored 24/7. In order to meet the very strict thresholds imposed on us, we deploy substantial technical resources, such as underwater acoustic screens (air bubble curtains) around the sources of noise. The acoustic thresholds that must not be exceeded are based on the German regulations, which are considered to be the most stringent in the world. “© AS Pokossy / Egis© Estelle Vaure / Egis
- Specific measures have also been put in place to protect seabirds (in particular the Barau’s petrels and Puffins) from light pollution. “This translates into 50 days of blackout from December to April to limit the risk of getting stranded” says Céline De Plasse. The rest of the year, the yellow-orange lights are directed towards the ground so as not to attract or disorient the birds. And if, despite all the precautions taken, we observe a stranded bird, the latter is taken immediately to the Reunion Society of Ornithological Studies (a local organisation for the protection of birds), to administer first aid.”
- At the Pointe du Gouffre, there is a coral rock outcrop with recognised ecological value. Among the measures taken to preserve it, a system for monitoring water quality, using monitoring buoys gathering real-time and continuous information on water transparency and water sampling to measure suspended solids levels caused by site operations. The columns of the future marine viaduct are therefore being installed under constant control: “Despite how long the work on the New Coast Road has been going on,the authorised suspended solidslevel (50 mg/l) has never been exceeded! We are all very proud of this, because it shows the effectiveness of the steps we have taken and our ability to anticipate risks upstream of any intervention.” exclaims Laure Camelin. “In addition to this monitoring mechanism, we have also implemented compensation measures: six columns on the main viaduct have been eco-designed to offer nursery habitats and, further out to sea, eco-reefs will be set up to support sustainable ecological development across the entire project area.”