Birs
Birs Waterfall in Laufen, November 2003
Course
The Birs springs from a source in 762 meters height slightly southwest of Tavannes, in the Bernese Jura. It occurs as a real flow to light ( power source), because the large amount of water comes from an underground river system. Deep inside the mountain, collects rainwater and flows through an extensive mile- long cave network.
The Birs meanders through wide valleys ( Vallée de Tavannes ) alternating with narrow, enclosed by high walls of rock gullies ( ravines ). In Delémont ( Delsberg ), the capital of the canton of Jura, it unites with the two streams La Sorne and Schelten. Between Soyhières and Lies mountain they change from French into German language area and passes into the the canton of Basel-Land belonging Laufental. In running it is at the crossing of a resistant limestone bank a waterfall whose water power was one of the starting points for the commercial development of the city.
When Klus Angenstein the river crosses the blue chain and enters the Birseck, the lowlands in Aesch. Between Aesch and Dornach can be found in the Birs numerous cancers, which feel very comfortable in the calm waters, the red American Cancer represents a threat to native crayfish species due to its aggressive behavior and that increasingly threatens to displace. The headwaters of the Birs belongs to the trout region, the underflow goes to the grayling region. Previously, the Birs was very dirty and contained by the people and the industry, but thanks to numerous restoration projects today thrives a diverse flora and fauna.
Up to this point the Birs has cut eight mountain ranges and put away a lot of rocks, when breaking through the gullies. After Klus Angenstein the Birs was strongly depending on the amount of water spread out and make their way. Therefore, it was tried early on to force the flow in a tight corset. Before the construction of Juratrain the river was straightened in 1875 and partially curbed. So dry pasture and building land was recovered and the construction of safe crossings for the growing traffic allows. Only the dense riparian forest at the heath in Reinach BL remained. The Reinacherheide is a nature reserve with poor grass stands, dry thickets and riparian forest. It is a paradise for birds with 83 different species of birds.
The Birsebene was sparsely populated until the end of the 18th century. Where once many poor sought the river the way to the Rhine, is where the modern Munich stone spreads today. The lower reaches of the river Birs forms the border between the cantons of Basel-Stadt and Basel-Landschaft and was stripped from a dead straight concrete channel to a livelier, more natural flow in 2004. Even traces of long-vanished beaver have been sighted again. The city limits of Basel and Birsfelden forming, the Birs flows at Birskopf after 73 kilometers to only 246 meters above sea level in the Upper Rhine.
Catchment area
The catchment area of 922.3 km ² and comprises Birs lies mainly in Switzerland, smaller areas are located in France. In Switzerland, the cantons of Bern, Jura, Solothurn, Basel-Landschaft and Basel-Stadt share. It extends over two linguistic regions (French and German ). Important neighboring catchments are those of Birsig, Ill, Rhône, Dünnern and Ergolz.
Tributaries
Important tributaries of the Birs are La Trame, Ruisseau de Chaluet, La Challère, La Raus, Schelten, La Sorne, Ruisseau de Mettembert, Luetzel, election Bach, Lüssel, Ibach, Chastelbach, castle grave Bach and Seebach.
Gallery
The Birs at Sorvilier
Waterfall (running) the Birs in Laufen
The Birs in Munich stone
Birswehr in the New World, Munich stone
Lower reaches of the Birs