Excenevex sand beach

You can find in Excenevex the only natural white sand beach on the Leman lakeside, located in a stunning alpine scenery.
Separated from Sciez by the Vion river, its gently sloping beach was the reason for its first settlement on Stone Age stilts. And the same beach is still the cause of a remarkable summer tourist boom, which will continue to grow as the bathing and botanical charms of its lake dunes, unique in Western Europe, become better known.

In the Bay of Coudrée, the widest part of the lake, violent northeasterly and southwesterly winds create long, hollow waves, which redistribute the fine sublacustrine deposits 5 to 50 m thick towards the bottom of the bay, on top of the glacier-bottom moraines. When the sands are exposed, the wind carries them inland, creating a system of dunes between the mouth of the Foron and Excenevex that is exceptional in Europe.
This phenomenon continues to this day, forcing the municipality to install sand nets on the beach in winter to limit the movement of sand.

The dunes : The only lake dunes in the whole of Europe, along with those of Hungary's Lake Balaton, their flour-fine sand is thought to have been deposited 12 or 15,000 years ago by the lake's eddies, soon after the Ice Age, when the Rhone current ran up against a sill cutting off Lake Geneva between the Pointe d'Yvoire and Prangins; the breaking of this barrier revealed a part of the lake which the winds shaped into some twenty undulations 600 m wide, and which was then fixed by vegetation ranging from shoreline reeds (now destroyed to clear the beach) to the true and venerable pine forest (stretching as far as Coudrée), passing through a flora which makes it an "oasis of special plants", where botanists have already discovered a large number of Asian specimens, a score of orchid species and, in a scientifically sensational juxtaposition, the only French station of the Arctic Creeping Buttercup.Excerpt from the guide "Le Chablais touristique" (Edition du Messager de la Haute-Savoie 1964).

In winter, this beach is a haven for lake wildlife, which specialists come to admire: ducks, swans, coots, scaups, grebes, sandpipers, barges, herons, egrets... which, during strong breezes, rest in the calm waters of the Vion, a small stream meandering through the La Pinède campsite, the natural boundary with the commune of Sciez.

In winter, and even more so in leap years, the level of Lake Geneva is lowered, revealing numerous lake dunes. The level of Lake Geneva is not always constant. In the days when Lake Geneva was unregulated, water level variations could reach more than 2 meters. They depended directly on the inflow of water from the rivers in the watershed.

Since 1884, flood protection around the entire lake has been guaranteed by an intercantonal agreement (GE, VD, VS) which sets the lake levels to be respected. Regulation is ensured by the Seujet dam in Geneva; in 1995, this structure replaced the Couleuvrinière plant and the Pont de la Machine dam, worn out by 100 years of daily regulation.

The normal maximum lake level is 372.30 meters from June to December, and the minimum level is 371.60 meters from March to April. Every 4 years (leap years), this level is lowered to 371.45 meters (to allow maintenance and repair work on lakeside structures), revealing more lake dunes. During floods or heavy rainfall, however, fluctuations can occur, raising the lake level by around 30 cm.