Swist

Swist in Meckenheim

The Swist is a stream of 43.6 kilometers in the Rhineland. It rises on the northern edge of the Eifel and flows between Weilerswist and Bliesheim from the right and south into the Rhine tributary Erft. Chance the Swist is also called Swistbach, locals often simply " Bach ".

Geography

Course

The source is at 330 m above sea level. NN in the northern part of the Eifel in Ahrgebirge, north of the village in the municipality Kalenborn Altenahr in the district of Ahrweiler. The Swist first flows at an average slope of 5 ‰ to Vettel Hoven (county) in the northeast and then runs with only 1.3 ‰ gradient by the Voreifel. She continues to flow along the western slope of the Ville of the plain landscape of Rheinbacher Lößplatte by Meckenheim Flerzheim, Morenhoven, Heimerzheim and Metternich. The municipality Swisttal and the place Weilerswist gave the creek its name. At 106 m above sea level. NN opens the Swist between Weilerswist and Bliesheim in Erftstraße.

Catchment area

The catchment area is located between the Rhine near Bonn or its smaller tributaries as Hardt Bach or Alfterer Bornheimer creek in the northeast and the receiving Erft to Euskirchen close to the west and wedges very soon from north-northwest. It is rural and includes the open hallway predominantly arable land. To the headwaters of the creek and its mainly left significant inlets there is next to meadows and pastures, especially a large proportion of closed forest. For larger part belongs to the catchment area of ​​North Rhine -Westphalia, in the headwaters also to Rhineland-Palatinate.

Inflows

Important tributary of Swist is the Steinbach, from left opens at station 15.7 miles as a young Bach in the Swist. Between Schweinheim vinegar and it bears the name Orbach. With a 48.227 km ² large catchment area of 20.5 km long river accounts for about 17% of the Swist. The following are the tributaries of the Swist be called.

Flow history

Originally, the Ahr went in today run bed of Swist. After the run was closed to the north by the raising of the Ahrgebirges, the Ahr but her bed looking in direct connection to the Rhine.

In places, there is the reference to the Swist as the longest creek in Europe. This is probably due to the originally highly meandering course in the area of ​​low gradient between Vettel Hoven and the mouth. Since the straightening of Swist at the beginning of the 20th century and ever since the channeling of the 1960s, this information is likely to be outdated.

Historic bridges

Remains of a bridge over the Prussian Swist at Miel

Prussian milestone on the old bridgehead at Miel.

The Roman aqueduct to Cologne crossed the valley of the Swist between Meckenheim and Rhine river with an arched bridge of 1400 meters length and up to 10 meters in height. The archaeologists believe that the bridge must have had 295 arches with a clear width of 3.56 m once. Is of the structure, except for a strip of low debris no longer obtained.

In Lützermiel the foundations of a Prussian bridge are obtained on the County Highway Bonn- Schleiden in 1823 crossed the Swist.

Water management and flood

The water level of the Swist varies greatly. The drain may be between less than 0.1 and 50 m³ / s at the orifice. So in 1961 occurred a great flood of Swist. Numerous places were flooded, some houses were accessible only by boat. Particularly hard hit were Flerzheim and especially Heimerzheim. Due to the high water of the natural course of Swist was substantially altered by the Erftverband in the following years. For long stretches, a so-called trapezoidal profile was created and edged the brook. Thus, the flow rate increased significantly; several flooded areas such as the former " Swistknick " at Dünstekoven fell away. During the work on many rural roads were built along the Swist that can be used by walkers and cyclists.

1984 came despite - or perhaps because of - the channeling again to a similarly severe flood in 1961 In 2009, led the Swist another strong flood, but there were only isolated cases of flooding..

A particularly problematic, the high flow rate and the lack of flood plains have been found. Not least in the Steinbachtalsperre flood situation, as their bottom outlet must be opened during heavy rainfall, as well as in 1961 and 2009.

In low-rainfall periods, however, many tributaries of the Swist fall dry. This is partly due to the lowering of ground water as a result of Sümpfungsmaßnahmen for opencast lignite mines.

Renaturation

Since the 1990s, the aim is to make the Swist more natural and to improve the water quality. After some preliminary work since 2003, the majority of measures 2013-2027 is to be realized. Thus, for example at Miel again flood compensation areas, so-called retention areas, and applied it to the stone facing of the creek be dismantled for long stretches.