Acher

The Acher (German pronunciation: [ˈaxɐ]) is a river in the districts of Ortenau and Rastatt, Baden-Württemberg, in southern Germany. It is 53.6 km long and flows from the Black Forest to the Rhine in a northwesterly direction, situated between the Rench to the south and the Oos to the north.

The source area of the Acher lies on the northeastern mountainside of the Vogelskopf (1, 055.8 m), an area marked by cirques which formed during the ice age. The spring, called Acherquelle, lies at a height of 848 m in the vicinity of the Ruhesteinloch, named after the Ruhestein Saddle to the east. It is located between the Vogelskopf and Seekopf (1, 054.2 m). The Acher initially flows northwards, descending sharply. It turns westwards at its confluence with the Seebach, which joins from the north from the Mummelsee below the Hornisgrinde. The Acher then flows through the trough-like valley of Seebach, where the valley reaches a depth of about 550 metres between the Hornisgrinde and the Vogelskopf. In this section, the Acher is also called the Seebach, hinting at the fact that this tributary stream from the Mummelsee was originally considered to be the main headstream of the Acher, despite its somewhat lower discharge. Below Vorderseebach, the Seebach merges with the Grimmerswaldbach coming from the north. The Acher valley then heads south for about a kilometre, roughly up to where the rugged Gottschläg valley joins it above Ottenhöfen. From the point on where the Unterwasser valley joins from the south, the Acher continues in a northwesterly direction, flowing through the municipality of Kappelrodeck toward the Upper Rhine Plain, which it reaches in the town of Achern; the largest town in the northern Ortenaukreis. In the Rhine Plain, the complexity of the river's course has increased due to numerous hydro-engineering measures, especially the Acher-Rench Connection (Acher-Rench-Korrektion) between 1936 and 1967. Still within the Black Forest foothill zone above Oberachern, the Acherner Mühlbach is severed from the Acher, which here has an average discharge of about 2 m³/s. The Acher itself, also called the Feldbach in Oberachern, then crosses the municipal a

Flows through: Germany.

River data from Wikidata (CC0); lengths normalised to a common unit.