(section names : Stollenbach - Mettinger Aa - Recker Aa - Hopstener Aa )
The little Hopstener Aa
|Water code||EN : 344|
|location||North Rhine-Westphalia , Lower Saxony ; Germany|
|Drain over||Great Aa → Ems → North Sea|
|source||Northwest of Lotte as Stollenbach
|muzzle||West of Lünne in the Große Aa
|Height difference||63 m|
|Bottom slope||1.3 ‰|
|Catchment area||368.048 km²|
|Communities||Mettingen , Recke , Hopsten , Schapen , Spelle , Lünne , Emsbüren|
The Speller Aa (section names : Stollenbach - Mettinger Aa - Recker Aa - Hopstener Aa ) is a 49.2 km long orographic left tributary of the Great Aa in the Westphalian Tecklenburger Land and Lower Saxony Emsland , Germany . At Hopsten , the river divides at a bifurcation . The branching off Giegel Aa also flows into the Große Aa.
The Speller Aa rises about three kilometers west-northwest of Lotte as a tunnel creek at an altitude of . Initially flowing mainly in north-westerly directions, it reaches Haus Langenbrück. The Vorthgraben flows here on the right and the Papiermühlenbach on the left . Furthermore, the river now changes its name and is called Mettinger Aa (from stationing kilometer 43.2), as it flows through the eastern municipality of Mettingen .
In the further course, small tributaries flow into the Aa with Hundevorthgraben , Köllbach and Mettinger Mühlenbach , before the 10.7 km long Düsterdieker Aa flows on the right. After the mouth of the Ölmühlenbach , the river is called Recker Aa (from stationing kilometer 35.5).
About 1.5 km south-east of Recke the Aa crosses under the Mittelland Canal in a 95 m long culvert . Now flowing more in a westerly direction, the river crosses Recke. The Ruthemühlenbach coming from the south flows here . In the further course the Schutbach and Meerbecke flow on the left . Below the mouth of the Meerbecke, the river Hopstener Aa is called (from stationing kilometer 26.9).
After another two kilometers of flowing, the river reaches Hopsten . Here the course of the river divides into Hopstener Aa and Giegel Aa at a bifurcation . While the Giegel Aa flows off in a north-westerly direction, the Hopstener Aa, also known as the Kleine Hopstener Aa because of the smaller amount of water , faces west towards Spelle . Below the mouth of the Breischen Bruchgraben , the Aa reaches the state border with Lower Saxony, which it forms for around four kilometers. After the confluence of the Trogbahngraben and the Getaugraben , the Aa flows entirely in Lower Saxony. Shortly below the mouth of the Flute , the name changes again with the mouth of the Dreierwalder Aa and is now Speller Aa (from stationing kilometer 12.5).
The Aa then flows through Spelle and then turns again to the northwest. After the confluence of several shorter ditches ( Speller Bahngraben , Venhauser Bruchgraben , Gescher Graben , Westermoorgraben , Bönnegraben , Heiteler Graben ) the Hesselter Bach still flows before the Speller Aa at flows into the Great Aa on the left .
From the source to the mouth, the stream overcomes a height difference of 63 m, which corresponds to a mean bed gradient of 1.3 ‰ for a river length of 49.2 km. It drains a 368.048 km catchment area over the Great Aa and Ems to the North Sea .
Due to the drought of the summer of 2018, the small Hopstener Aa or Mühlen-Aa dried out for several weeks. In August and September, due to the low water level, no more water flowed over the weir on Rheiner Straße in Hopsten. All the water, which was already very little, flowed a little upstream at the bifurcation into the Giegel Aa . In the dry run of the river, the fish collected in the remaining pools and were resettled by the local fishing club.
See also: List of waters with Aa
- German basic map 1: 5000
- Topographic map 1: 25,000
- Topographical Information Management, Cologne District Government, Department GEObasis NRW ( Notes )
- Water directory of the State Office for Nature, Environment and Consumer Protection NRW 2006 ( Memento from February 15, 2010 in the Internet Archive ) (PDF; 1.03 MB)
- In Ibbenbürener Volkszeitung from August 14, 2018: "Anglers save fish from the mill Aa"