Aabach (Greifensee)

Ustermer Aa at the Pfäffikersee in Wetzikon - Robenhausen

The Ustermer Aa or Aabach (not to be confused with the Mönchaltorfer Aa) is a non- navigable small river in the Canton of Zurich; 11.2 kilometers of the longest tributary of the Greifensee. It originates from the Pfäffikersee whose drain it forms, to the southeast. In Wetzikon it turns west, first traverses in close Aatal the Oberustermer Forest and flows upstream of the mouth (435 m above sea level. M. ) in the Greifensee examination.

Industrial history

The Ustermer Aa loses her short run 100 meters altitude, and therefore drove in the Middle Ages five mills; was in the 19th century the center of the cotton industry in the Zurich Oberland. 15 spinning operations at their run made ​​it the " million -Bach ". In the 20th century found a concentration of textile industry rather than on a few farms.

Industry and channel restoration

To protect against flooding of the creek was heavily engineered and channeled. Currently projects are realized, whereby the stream and renatured by fish ladders and reduced thresholds fish migration in the Aa should be possible. In addition, the city of Uster wants to expand the parks along the watercourse.