Versoix (river)

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The Versoix is a 27 km long river, which rises on French territory and ends at Versoix in the Swiss canton of Geneva in Lake Geneva. They drained a section of the plateau between Lake Geneva and the Jura Mountains and belongs to the catchment area of the river. The area of the catchment area of Versoix is 89 km ².

Geography

The headwaters of the Versoix is located at about 600 m in the foothills of the Jura mountains on the first municipality of Divonne- les- Bains in the French department of Ain. The top section of the creek is called Divonne. The Versoix flows initially eastward through the town of Divonne- les- Bains and reached shortly thereafter to 465 m wide valley, which is separated by the ridge of Chavannes from Lake Geneva. Here, the creek turns with a sharp arc south-southwest and by now flows on a longer route parallel to the western shore of Lake Geneva, where it forms the border between Switzerland and France about 9 km. In the broad valley floor are larger wetlands, which the Versoix, whose slope is now less than 0.1 %, crossed with numerous meanders.

Only below Versoix of the Versoix begins gradually into the surrounding plateau einzutiefen. From the West here opens the Oudar, which rises in the Pays de Gex on the Jura south slope. The Versoix features now again an arc flows to the southeast and occurs entirely on Swiss territory ( Canton of Geneva ) above. It is located in a valley, which is about 15 to 20 m deeper than the adjacent land and has an up to 300 m wide, flat flood plain. At La Batie it receives with the Creuson the second significant inflow. South of the town of Versoix opens the same river with a small alluvial fan into the lake.

Long stretches of the Versoix flows in a creek bed, its natural or semi-natural state is obtained. Despite the use of water since the Middle Ages, the shores are installed only in the area of Divonne- les- Bains and Versoix.

Hydrology

The Versoix has a nivopluviales flow regime. Flood can in the spring during snowmelt in the Jurassic and later in the year when severe thunderstorms or prolonged rainfall occur. Fed by the karst water body in the Jura leads the Versoix, even after prolonged dry periods compared with other rivers of similar length of the route still relatively large amount of water. The mean annual river discharge at Versoix is 3.7 m³ / s

Fauna

In Versoix trout, grayling and sculpin occur. In the natural course of the river was begun in 1956 with the first reintroduction of beavers project in Switzerland. The population has since established itself here.

History and use

Is first mentioned, the river name in 1319 under the name Aqua Versoye. Later, the names Versoya ( 1497 ) published, Versois ( 1730) and Versoie ( 1906). The name derives from the old French word versoi or bersoye (slip angle, braid of willow ).

Even in Roman times, a part of the source water of the upper Versoix has been derived and implemented with an aqueduct to the city of Colonia Iulia Equestris ( Nyon ).

Since the Middle Ages the water power of the Versoix for the operation of mills and forges was used. In the 16th century occurred in their place the paper mills (especially in Divonne- les- Bains, in Versoix and at La Batie ). The paper mill of La Batie 1880 closed. Then there was a paper mill, but had to give up in 2000 to operate in Versoix.

At three different places water is derived from the Versoix. This was already partially done in the Middle Ages in order to provide the streams that flow directly into the lake and in the summer hardly led water with a constant as possible water capacity that is sufficient both for use by mills as well as for the irrigation of agricultural areas. These include the channel discharge to the streams Greny ( opens in Coppet in Lake Geneva ) and Brassu ( Estuary at Céligny ) and the Canal de Crans, of the Nant du Pry fed at Crans- près -Céligny. The third channel, which was inaugurated in 1785, the water of Versoix of La Batie about 5.4 km along the northern side of the valley for industrial and irrigation purposes after Versoix -la -Ville is performed, which was newly established at that time.