The Karthane is a left tributary of the Stepenitz in the district of Prignitz. Its length is 48 kilometers, it has tributaries such as the Cederbach and a number of smaller streams and meadow ditches.
The Karthane, which is one of the best preserved river systems in Brandenburg with the Stepenitz and Löcknitz, flows from the source area, initially to the south, through the Vehliner Luch and then to the west through the Plattenburg pond landscape. From there it winds its way slightly northwest to Bad Wilsnack, where it reaches a maximum width of 10 meters and a water depth of 0.6–1.5 meters. In this area, the Carthane forms depressions in the curve area, called carp, in which carps find hiding places. A specialty is the occurrence of the hazel, a species of fish that cannot be found in any other Prignitz body of water. North of Bad Wilsnack, the Karthane flows through the Karthan area named after it. In this FFH area breed among other things sea eagles (endangered), black stork (endangered) and crane (endangered). Behind Bad Wilsnack the Karthane flows in wide arches first in a southern and then in a northwest direction through the Elbtalaue, here it reaches 18 to 25 meters in width, a few kilometers before the mouth there is an approximately 800 meter long and 70 near the village of Klein Lüben Meter wide area called the Wide Carthane.
Source: Wikipedia