Sihl

The Sihl at Sihl

Sihl is a Swiss river and the largest tributary of the River Limmat. You drained parts of Schwyz pre-Alps and flows into a narrow corridor south of Lake Zurich and north respectively. east of the catchment area of Reuss and Reppisch to the northwest of the city of Zurich to where it leads. Sihl is 68 km long and drains an area of 341 square kilometers.

The river's name comes from the Celtic and means the Strong.

Course

The Sihl rises at the north-eastern slope of the Drusbergs in Canton Schwyz south of Student and east of the high - Ybrigs.

In Einsiedeln it is dammed to Lake Sihl, which with a surface of 11 km ², the largest reservoir in Switzerland. Below the dam the river Sihl results according concession 0.3 m³ / s to 0.4 m / s respectively at the Zurich cantonal border to 2.5 m³ / s to 3.0 m³ / s of water. Average 88 % of the natural inflow could thus be used for energy production. This water is passed through the Etzel by pressure line to Altendorf SZ to the power plant and from there into Lake Zurich. Where is the Lake Sihl today, there were already 15,000 years ago, a natural lake of even greater area.

A little below the dam the river Sihl is crossed at Egg SZ of the Devil's Bridge, which connects via the Camino de Santiago Pfäffikon and the Etzelpass with Einsiedeln. Immediately next to her in 1493 Paracelsus was born.

An important tributary is the Alp, which opens at Biberbrugg. Slightly below Schindellegistrasse leaves the Sihl the Canton of Schwyz, a piece flows well through the canton of Zurich and then limited him from huts to Sihlbrugg against the Canton train. In this section are in Schoenberg rapids, the so-called Sihlsprung.

From Sihlbrugg Sihl flows through Zurich Sihltal, accompanied to the left of the mountain chain of the Albis and right of the shallower slopes of the Zimmerberg. Between Sihlbrugg and Langnau am Albis is the Sihl Forest, a nature reserve owned by the city of Zurich and the previously significant for the wood supply for the City Forest. The distance above Sihlbrugg was less suitable, so it always came to high losses for timber rafting. Then the Sihl happened Knives and reaches Leimbach the city of Zurich. In this section, it loses a large part of its water, as many factories have secured "on eternal time " a water right of use in the 19th century, for energy or process water. Through numerous corrections of the river bed, the large flow rate was reduced during this period.

In Zurich - Brunaupark lies over the river on bridges an urban motorway, the Sihlhochstrasse. From the Sihlhölzli the waters flowing again open and is in addition to other traversed by the Stauffacherbrücke. In the last hundred meters, it unites with the water of the Lair trench, a grave rest of the southern fortification of Zurich. Then they come in under the 16 above-ground tracks of the main railway station and ends at the place pointed at the National Museum in the River Limmat.

Earlier estuaries

The Sihl transported earlier 18,000 cubic meters and more sediment per year from the Alps to the area of Zurich, where these deposits dominated the underground. The delta of the river Sihl included in prehistoric times but not only today's estuary in the Limmat river, but extended south of the Lindenhof hill, which spilled into the lake of Zurich with many mouth arms.

In the 1st millennium BC, the approach undertaken by the Sihl rubble accumulated on the outflow of the river Limmat. Thus, the mirror of Lake Zurich increased significantly. At that time, likely many areas today, the banks have been floodplains, including the area around the Upper Station Street and the parade ground. By removing the debris at the Sihlmündung in the Limmat in Roman times, the water level of Lake Zurich fell sharply, then why buildings could be built on again today flooded area. Even then flowed one arm of the Sihl Muensterhof in the Limmat.

In late - or post-Roman period no more debris was removed, the lake level rose rapidly again for several centuries, and again poured down several Sihlarme in Lake Zurich. During the early Middle Ages, the Sihl is regulated again. Ever since the year 853, when the woman Münster was founded, the lake level must have lain at the current level. All Sihl has since passed north of the Lindenhof hill in the Limmat, anstauendes rubble was removed.

Even into the 20th century was a Sihlarm - mentioned in sources from the 15th century as opposed to the main arm Wilde Sihl Tame Sihl, later Sihlkanal - initially led these days by the city walls, and then over the Schanzengraben in the city north of the race route. He drove into the city water wheels and culminated in the Covered Brüggli in the Limmat.

Flood hazard

At a fraction of the Sihl Dam parts of the city of Zurich would be several meters high flooded. The tidal wave would reach the upper city limits in Leimbach after one and a half hours, the center is almost two and the lower city limits at Altstetten after nearly three hours.

Pictures

Sihl below the Sihlsprungs

In Zurich - Brunaupark

Sihl and Sihlhochstrasse in Zurich - Brunaupark

Confluence with the River Limmat (rear) in Zurich