The Leina Channel forms a connection from the Hörsel headwaters Leina - and the (upper) Apfelstädt from the system Gera/Unstrut/Saale/Elbe - to the subsystem of the Nesse. It was already built in the Middle Ages to supply the town Gotha with water from the Thuringian Forest, and to which the Nesse flows via the Wilder Graben. The catchment area of the Wilder Graben is with 104.6 km² barely smaller than that of the Nesse above (131.4 km²), in addition there is the proportionate catchment area of Leina (estimated by TLUG Jena to be 20.8 km²) and Apfelstädt. In purely mathematical terms, the length of the Nesse River over the upper Leina, Leinakanal and Wilden Graben is 63.5 km.