In 2017, Firestone supplied 23,000 m² of 1.1 mm thick GeoGard EPDM geomembrane to waterproof a large private irrigation reservoir in St Andre de Lidon, in the west of France. With a capacity of 120,000 m³ of water, the reservoir was destined for the irrigation of corn and potato crops during the summer months.
In this region, the right to extract water from the natural environment has been decreasing in volume each year. The creation of a substitute water reservoir made it possible to compensate for this by drawing and storing water only during the winter rainy season, when there is a surplus in the upper water table, and using the water contained in the irrigation reservoir in the period from April to October.
A round shape was chosen for the reservoir to maximize the volume of stored water and reduce the amount of excavated soil. After the excavation works, a geocomposite gas drainage system was installed over the compacted earth, followed by a layer of geotextile and finally the waterproofing geomembrane. To facilitate the installation process, the 30.5 m x 15.25 m GeoGard EPDM membrane panels on the embankments were cut and pre-assembled off site into trapezoidal sections.
Located just 30 km from the ocean, the site was often exposed to rain and strong sea winds. Despite this, the entire installation process only took 10 days, which is impressive for an irrigation reservoir of this size.
“This reservoir has allowed us to irrigate trouble-free for three years, without constraints to use the water from the reserve. Firestone annually monitors the behavior of the geomembrane, which reassures me about the aging of the reservoir,” explains Mr. Fabien Chaboisseau, director of SCEA Chaboisseau, the company that owns the reservoir.