Lake Geneva
Between you and I
Crossed by the Rhone, I am the largest lake in Western Europe. I am called Lac Léman in France and Switzerland, while in English they like to call me by the city that lies on my shores: Lake Geneva. I cover 580 km² and contain 89 billion m3 of water. The region surrounding me, shared between France and Switzerland, accommodates 1.6 million people. Demographic pressure and climate change are the two major challenges confronting me in the years to come.
Located in an old glacial valley, I lie at an altitude of 372 m. I am 72.3 km long and 13.8 km wide, while my maximum depth is 309 m. My water tempers the prevailing continental climate, bringing mildness in winter and coolness in summer. My surface area is shared by Switzerland, with 347 km2 and France (234 m2), while my shores are practically ¾ Swiss (142 km in Switzerland versus 58 km in France).
Technical information
- Length: 73 km
- Hydrographic basin: 7,975 km2
- Surface area of lake: 580.1 km2
- Dwell time of water: 11.3 years
- Rainfall: 1,000 mm/year
- Main cities: Geneva, Lausanne, Montreux, Evian-les-Bains, Thonon-les-Bains
- Main tributaries: Rhone (75 %), Dranse, Venoge
A little history
It’s the glacier of the Rhone that shaped me during successive periods of glaciation. I took my present shape during the last period of glaciation, nearly 12,000 years ago. The first traces of human settlement go back to the upper palaeolithic and vestiges of villages built on piles (about 4,000 years ago) have been discovered along my shores.
I have belonged successively to the kingdom of Burgundy (888-1032), the Holy Roman Empire and then the Duchy of Savoy until 1803, when the region of Vaud joined the Helvetic confederation. In 1815, Geneva and Valais, until then annexed to France, also became Swiss. This rallying of regions signalled the end of economic wars and conflicts between the Swiss and the Dukes of Savoy regarding who should rule over me.
My uses
Tourism
Tourism started on my banks in 1830, with the construction of the first wharves, close to Geneva. It is still flourishing today and an array of activities have developed: luxury hotels, restaurants, international conferences, cultural and sports events, and so forth.
I also host nautical activities like bathing, windsurfing, pleasure boating and canoeing, practiced at 64 marinas 12 of which are on my French shores, and more than a hundred beaches. Developing these structures nonetheless leads to the artificialisation of soils and the disturbance of the fauna and flora.
Commercial navigation
The Compagnie Générale de Navigation (CGN) organises tourist cruises and regular crossings. Thus, 4 lines link the towns on my shores. Nearly 100 crossings take place every day.
Drinking water: to my health!
All these activities mustn’t distract from the most essential service I render: I provide drinking water to almost 900,000 people! I supply 90% of the drinking water of the Canton of Geneva, the other 10% comes from groundwater.
My governance
Two international bodies watch over me
During the 20th century, it became apparent that human and agricultural activities caused eutrophication, that’s to say the strong concentration of nutritive substances such as nitrogen and phosphorous in my waters, leading to the pollution of groundwater and threatening biodiversity. This observation resulted in the foundation in 1963 of the International Commission for the protection of Water Lake Geneva (CIPEL), responsible for monitoring the quality of my water. 158 water treatment stations will be built.
The CIPEL establishes a regular assessment of pollution levels and organises treatment measures. It can also address recommendations to fight present and future pollution to the French and Swiss governments. A cross border organisation, the CIPEL is funded by the Swiss Confederation (30%), the Canton of Vaud (23.85%), the Canton of Valais (9.45%), the Canton of Geneva (11.7 %), and France (25%).
Another cross-border organisation, the Lake Geneva Council is responsible for the economic and cultural dimensions of my geographic area. Founded in 1987, its purpose is to build and strengthen the Genevan identity through economic, cultural and social projects.
Rules established together
The rules governing navigation on my waters were established by France and Switzerland in the framework of a bilateral agreement, the French-Swiss Regulations on Navigation on Lake Geneva.
As for fishing, the agreement of 20 November 1980 was aimed at harmonising the fishing activities organised on my waters. This agreement also determines the biotopes and fish species that must be protected.
A still fragile habitat
Despite intense urbanisation and heavy demographic pressure, I accommodate a wealth of biodiversity: sedentary and migrating birds, and more than thirty species of fish. Certain spaces have been classified as zones of ecological interest for fauna and flora (ZNIEFF) and some bear the Natura 2000 label. I have also preserved several wetlands.
These spaces remain fragile, subject to the pressure of human activities and the impacts of climate change: the increased temperature of my waters can be fatal for certain fish species such as the lake whitefish and the char, while favouring the development of invasive species.
Several objectives must be pursued to ensure my future:
- Continue to provide my services to the surrounding region while controlling the impacts of the uses made of me;
- Continue improving the quality of my resource and habitats, through controlling discharges of wastewater, rainwater and wastes, and the renaturation of my shores;
- Adapt to climate change.