Großache

Großache also Jochberger Ache and Kitzbüheler Ache (A), and Tiroler Achen (D)
The Tiroler Achen in the Entenloch Gorge
Location	Traunstein district, Bavaria; Kitzbühel district, Tyrol
Reference no.	DE: 184
Basin features
Main source	Thurn Pass, Pinzgau, Salzburg 1,270 m (AA) 47°18′33″N 12°24′37″E / 47.3092°N 12.41029°E / 47.3092; 12.41029Coordinates: 47°18′33″N 12°24′37″E / 47.3092°N 12.41029°E / 47.3092; 12.41029
River mouth	Chiemsee 518 m (AA) 47°51′51″N 12°29′59″E / 47.864069°N 12.499802°E / 47.864069; 12.499802
Progression	Chiemsee → Alz → Inn → Danube → Black Sea
River system	Danube
Landmarks	Large towns: Kitzbühel Small towns: St. Johann in Tirol, Kössen, Marquartstein
Tributaries	Left: Reither Ache, Schwarzlofer, Right: Fieberbrunner Ache, Kohlenbach, Weißenbach from the Walchsee
Physical characteristics
Length	79 km
Discharge	Minimum rate: Average low: 11,8 m³/s (Staudach gauge) Average rate: 35.5 m³/s Maximum rate: Average high: 342 m³/s

The Großache is a river, 79 kilometres (49 mi) long, in the east of the Austrian state of Tyrol and the Bavarian region of Chiemgau.

The river is known by four different names, each applying to a different section of its course: above Kitzbühel it is the Jochberger Ache, from Kitzbühel to St. Johann in Tyrol it is known as the Kitzbüheler Ache, in its middle reaches as the Großache, a name also used for the entire Austrian section , and in its lower reaches in Germany as the Tiroler Achen. It rises on the Thurn Pass on the territory of Salzburg province, reaches the Tyrolean border after just 400 metres and the German border after 55 kilometres (34 mi), discharging 24 kilometres (15 mi) later near Grabenstätt into the Chiemsee lake.

The Großache is not the only river whose name changes at the border of 2 countries that share the same language. A variation of its Austrian name is the Große Ache; the Bavarian section is also called the Tiroler Ache. The term Achen is not a plural form, but a peculiarity of the Bavarian dialect. The name Kössener Ache is also used.

In many publications, even the more serious ones, the length of the Austrian section of the river is often erroneously given as 48 km and on many maps the start of the river in Salzburg provinces is left out. On the official Austrian 1:200,000 scale map the highest part of the river is shown as the Trattenbach, which is longer and also delivers greater quantities of water than the nominal headstream of the river.

The nominal source of the Jochberger Ache lies at 1270 m above sea level on the Thurn Pass. A few of its early tributaries are, however, larger and have a greater discharge. The most important is the Trattenbach which starts as a trickle from a high cirque at about 1900 m above sea level between the mountains of the Zweitausender and the Rossgruberkkogel south of the Kleiner Rettenstein, and is fed by several other springs before it joins the Jochberger Ache.