upper course name: Alaubach
Mönchaltorfer Aa shortly before the confluence with the Greifensee
|Water code||CH : 611|
|Drain over||Glatt → Rhine → North Sea|
|source||in Feissiholz near Herschmettlen
|muzzle||between Rällikon and Riedikon in the Greifensee
|Height difference||98 m|
|Bottom slope||8.8 ‰|
|Catchment area||51.14 km²|
| Discharge at the Mönchaltorf
A Eo gauge : 46 km²
Location: 2.4 km above the mouth
|77 l / s
1.05 m³ / s
22.8 l / (s km²)
50.5 m³ / s
|Communities||Grüningen , Bubikon , Gossau , Mönchaltorf , Uster|
The Aabach ( also called Mönchaltorfer Aa to distinguish it from the Ustermer Aa of the same name ) is a non-navigable small river in the canton of Zurich . At 11.2 kilometers, it is one of the two main tributaries of the Greifensee, alongside the Ustermer Aa . The Mönchaltorfer Aa rises at height of in Feissiholz near Herschmettlen near Bubikon . The brook flows on its way to the northwest through Grüningen and Mönchaltorf and then flows into the Greifensee. At the lower reaches of the Mönchaltorfer Aa forms the border between the municipality of Mönchaltorf and Uster .
In its confluence with the Greifensee, the Aabach forms a spacious delta. A moor overgrown with reeds extends in this area, which extends from Riedikon in the east to the Egg bathing establishment in the west and houses a nature and bird reserve as well as the "Silberweide nature station". Numerous native amphibians and birds can be found here. Among other things, white storks nest in the Aabach delta .
- Geoserver of the Swiss Federal Administration ( information )
- Hydrological Atlas of Switzerland of the Federal Office for the Environment FOEN, Table_13
- Topographical catchment areas of Swiss waters: sub-catchment areas 2 km². Retrieved September 8, 2017 .
- Aabach-Mönchaltorf 1980–2016. (PDF) Position 527: monthly samples. In: Office for Waste, Water, Energy and Air, Department of Water Protection. Retrieved August 9, 2017 .
- Archive link ( Memento from August 1, 2015 in the Internet Archive )