Mangfall Canal

The Mangfall is a 58 km long left tributary of the Inn in Upper Bavaria. It is the outflow of the Tegernsee and flows into the Inn in Rosenheim.
Source and further information
de.wikipedia.org/wiki/Mangfall

The Mangfall was built in the Middle Ages. Initially, mills used water power. In 1810 a salt works was built in Rosenheim to boil the brine coming from Bad Reichenhall. So that enough wood was available, the Mangfall was further built for the Holztrift. Numerous diversions were built from Tegernsee to Rosenheim. The factories made it easier for themselves to drift through the wood with the canals, but they also use the canals to generate energy. For example, shortly before Bruckmühl, part of the water from the Mangfall is channeled into a partially artificially created canal, the approximately 10-kilometer-long Triftbach. This passes numerous factories and only flows back into the Mangfall at Bad Aibling.