The biggest river in the greater Kitzbühel area is Großache. It flows from St. Johann in Tirol via Kirchdorf and Kössen to Lake Chiemsee. In the winter, the river is at a low and freezes in parts. The Großache, which is home to a great variety of birds, fishes and insects, offers beautiful walking opportunities.
In Kirchdorf there is a small chapel next to the river, which was built in 2002 to commemorate the training of the Großache. Between 1996 and 2002, a section of the river between Furthersteg and the sewage treatment plant in Erpfendorf was lowered and rewilded to avoid floods and to restore the aquatic ecosystem.