Radolfzeller Aach

Mühlkanal of Radolfzell Aach in Singen (Hohentwiel )

The Radolfzell Aach (also Hegauer Aach ) is a 32 km long, right or northern tributary of the Rhine in the south of Baden- Württemberg ( Germany ). The river rises in Aach at 475 m above sea level. NN located Aachtopf, the largest spring in Germany.

Geography

Aachtopf

The water of the Aach comes from a 18 m deep underground karst cave and comes to about two-thirds of the Donauversinkungen between Immendingen and Möhringen and in Fridingen.

Course

According to their origin as it flows through the Hegauer Aach Hegau and numerous nature reserves. They only flows in a southerly direction to Singen (Hohentwiel ), where it is crossed by the bushel bridge, then east and is called in its lower reaches Radolfzell Aach. The underflow runs on the last six kilometers in the nature reserve Radolfzell Aach Ried. It opens with an average discharge rate of ten cubic meters per second as the fourth largest inflow into Lake Constance. The mouth is located between Radolfzell and moss in the northwest part of the lower lake, the Zeller lake.

Catchment area

The Radolfzell Aach drains a catchment area of 261 km ². If one adds the catchment area of ​​the Danube before the Donauversinkung due to the Aach pot to it drained to the full percolation days of the Danube catchment area of 1,560 km ².

Hydrology

In earlier times, the water power of the fast flowing Radolfzell Aach has been used for many mills. Today, several hydropower stations are on their shores. Restoration measures, there are, for example, in Beuren on the Aach, where a sediment catcher was set up in front of the Singener district to collect sediment and gravel that leads to the river with it. First thoughts, the sediment above Volkertshausen return them to the river, were abandoned.

Fauna

Can be connected to the Radolfzell Aach several endangered water bird species, including Snipe, Wood Sandpiper and Green Sandpiper. The estuary has in 1998 after 200 years of settled again for the first time the Beavers. Gewässermorphologisch the Radolfzell Aach belonging to the lower trout and grayling region. Fish species in the Aach is the brown trout, grayling since the exposed due to their low aversion to the grazing pressure of the great cormorant colony in Radolfzell Aach Ried stronger. There are also sizeable populations of the endangered fish species brook lamprey and bullhead, protected at the basic living. In the lower reaches, other species of fish from Lake Constance are added.

Towns

At the Radolfzell Aach the villages Aach, Volkertshausen, Beuren be due to the Aach, the Friedinger Riedmühle, Hausen an der Aach, Singing (Hohentwiel ) Rielasingen- Worblingen, Bohlingen and Radolfzeller community part Rickelshausen.

Water

Due to the strong Aachquelle the Radolfzeller Aach is open year-round for canoes. However, the section Aachbad singing to Bohlingen is not recommended because many water discharges and heavy industrialization. The underflow in the nature reserve is open all year locked for water sports.