Dreisam

The Dreisamstadion in Freiburg below the Schwabentorbrücke

The Dreisamstadion (Celtic: * tragisamā, " very fast ") is a 29 km long, left or southern tributary of the Elz river in Baden- Württemberg ( Germany ).

Course

The Dreisamstadion takes its beginning in Dreisamtal in the southern Black Forest in Baden, near the Bridge of the state road 127 from Kirchzarten to webs as the confluence of Rotbach and Wagensteig Bach.

From the point of this "river wedding " in the west of the southern Black Forest below the traversed by Rotbach Hollental and Wagensteigtals the Dreisamstadion flows im Breisgau channeled to the west, reached the eastern end of Paving the city of Freiburg and assumes, among others, the waters of the crooked stream and the Brugga from south of Eschbach's on from the north. On Dreisamstadion ( " Mage Solar Stadium " ) over the river leaves the Black Forest flowing to the west. To the east of the city water is diverted for the " Commercial Service" and the Freiburger Baechle the " sand trap ". This watercourse is divided into the old town into a " northern arm " and a " south arm ". The majority of the Südarms leads immediately to the west of the " Höllentalbahn bridge " in Stühlinger district back into the Dreisamstadion; the remaining water flows towards the west, the areas of ash wood and Bishop Linde and flows in fief also back in the Dreisamstadion. The northern arm flows (often underground) through the northwest in the direction of the Old Town neighborhoods Beurbarung and Brühl and flows west of Gundelfingen in Pushed stream, which in turn flows at Nymburk - Bottingen in the Glotter. Thus ends this Freiburg Bächlewasser just before bar back to the Dreisamstadion. The Dreisamstadion itself flows in the Freiburg city area in north- westerly direction extending along the B 31 After passing the A 5 it flows over the eastern edge of the Imperial March chair and the western edge of the Nimbergs contrary to Riegel, where it empties into the Elz.

The Dreisamstadion was channeled from 1817 to 1842 under the direction of Johann Gottfried Tulla over its entire length of Kirchzarten to bolt. However, in the east of Freiburg it is to be rehabilitated at a length of 800 m. It overcomes Kirchzarten (377 m above sea level. NN ) to its estuary (178 m) in the Elz river in the municipality of latch 199 m height. 135 m above or south of its mouth flows the Dreisamstadion to the coming of South southeast Glotter.

Right in the mouth region of Dreisamstadion in the Elz northeast of St. Michael's Mount (241 m above sea level. NN ) leads coming from South - southwest Old Dreisamstadion.

Flood

Just below the confluence with the aforementioned Elz branches of about 15 km long Leopold Canal. About this channel the water of the Rhine Dreisamstadion is fed at high water. The channel ends northwest of Rheinhaus southwest of Rust and west of the nature reserve Taubergiessen.

Because of the extremely steep topography and climatic and orographic rainfall caused high Dreisamstadion the catchment is considered particularly prone to flooding: Feldberg to level Make straight the average slope angle is 21 ° or 43 % slope. The round shape gives the area a high aspect ratio (0.7) and a high Kreisförmigkeitsverhältnis (0.55 ), which has a temporal runoff concentration result and thus can quickly lead to flooding. The predominantly hard rock aquifer has low water storage capacity, forcing the water especially at high rainfall to rapid runoff. The maximum outflow is due to snow melt instead coupled with spring rainfall in April. In summer, the highest rainfall ( high water sales) are expected, however, cause for simultaneous high water turnover of vegetation only to secondary outflow maxima.

A historically known flood, in which several bridges were destroyed and two people (see Carl Siegel ) were killed, occurred in March 1896. Because the Dreisamstadion today straightened from Freiburg and is secured on both sides by high water dams, run the flood into the usually without major damage. In a flood on 23 December 1991, however, damage was caused by flooding in the east of Freiburg. Under the bridges of the Rhine Valley line the riverside paths are often submerged at high water, which has cost the lives despite warning labels in 2010 and 2013, two cyclists. The city wants to install barriers.

Catchment and inflows

The catchment area includes the Dreisamstadion to bolt an area of 568 km ² and is one of the catchment areas of medium size in Germany. It has a widely ramified ( dendritic ) drainage system and can be characterized as a complex flow regime of the first degree, which is characterized by two major runoff. Here, a maximum discharge rate is measured in spring ( snow melt) and a second, smaller peak in the summer or fall at the time of highest rainfall.

Among the tributaries of the Dreisamstadion include except the headwaters Rotbach and Wagensteig Bach ( downriver considered ): Krummbach ( in the upper reaches Zastler Bach called ), Brugga, Eschbach and Glotter.

Use

Previously, the Dreisamstadion water powered mills, supplying power for commercial businesses such as gemstone cutters and tanneries. Once again there are small river power plants, for example, the sand trap. The fishing today no longer plays a role, even before salmon were caught in the river.

Today the Dreisamstadion is used with its riverside paths and meadows for walking, grilling and swimming as a recreational area. Even for individual she is with the bike path on the south shore or the roads on both banks of in the city of Freiburg and the feeder middle (main road 31 ) to Betzenhausen important.

Since 2011 takes place on the Dreisamstadion in Freiburg city annually a " duck race " as a fundraiser. Thousands numbered plastic ducks are dumped into the river and a few hundred meters down again removed.

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