Framework agreement for the realization of a study of the terrestrial and marine natural environment as part of the underwater pipeline project between the continent and Porquerolles island
CLIENT: COMMUNAUTE D'AGGLOMERATION TOULON PROVENCE MEDITERRANEE (CATPM)
LOCATION: VAR - 83 (FRANCE)
- Multibeam bathymetry and side scan sonar surveys
- Phanerogam herbaria: mapping and vitality
- Pinna nobilis: density evaluation
- Benthic communities of soft substrates and sediment quality
- Benthic communities of hard substrates
- Water quality
- ERC measures
The island of Porquerolles is supplied with drinking water by several wells and boreholes distributed in the plains of la Ferme, la Courtade and Notre Dame. For many years, the water from these aquifers has a high level of salinity which led the Municipality to request a waiver from the Superior Council of public Hygiene of France. In 2002, the Municipality started to consider the sustainability of the drinking water supply. Due to the sensitivity of the sector (classified site, protected species, etc.) and the expected level of definition, a definitive solution had not yet been implemented. Unfortunately, the consecutive droughts since 2003 accelerated the penetration of the salt wedge inland, and therefore of the water from the boreholes, by an increase in the salinity. Concerned to preserve the natural environment, especially the aquifers, the municipality chartered since 2004, tankers pouring fresh water collected and treated on the continent into the water network of the port of Porquerolles from April to October. Drastic restrictions on use are implemented each year starting in May, combined with awareness campaigns. However, these measures turn out to be insufficient to guarantee a good preservation of the aquifers and generate a general discontent of the users. In this context, in 2006 the city of Hyères initiated a first project to implement a drinking water pipeline between the end of the Giens peninsula (site of the Tour fondue) and Proquerolles. This project led CREOCEAN to carry out an environmental impact study and to submit a file to the National Council for the Protection of Nature (CNPN) towards the destruction of part of the posidonia meadow. Despite the administrative authorizations granted, the first project did not result in the implementation of the works.
In 2018, the drinking water pipeline project between the mainland and Porquerolles was relaunched by the Toulon Provence Méditerannée metropolis, aiming at improving and securing the island’s drinking water supply.
The objective was to acquire the environmental data on the marine environment necessary for this project, which would be used for the creation of administrative authorization files, including a request for a waiver for the destruction of protected species and a Natura 2000 impact report.