Mainaschaff barrage, Barrage in Mainaschaff, Germany.

Mainaschaff barrage was a dam on the Main between Mainaschaff and Stockstadt, west of Aschaffenburg. It had a 400 m long and 12 m wide Floßgasse (raft channel) on the right bank, a lock chamber and fish ladder on the Stockstadt side, and a hydroelectric plant with three turbines in midstream. A footbridge linked the banks. The barrage was demolished in 1972; remains of the lock chamber are visible on the Stockstadt side.

The Main was developed for navigation to Offenbach between 1883 and 1900; delays between Bavaria and Prussia pushed works upstream to 1914, when construction of the Mainaschaff barrage began. It opened in 1919 with a impoundment level of 2.4 m. During the Second World War, machine-gun bunkers built into a pier and beside the raft channel served as command posts. The Kleinostheim barrage replaced it, the power plant stopped on 6 June 1971, and the structure was demolished in 1972.

The former sluice channel, the Floßgasse, was used as an open-air swimming pool in the summer months. The old course of the Aschaff, diverted about 2 km into the tailwater for the barrage, can still be partly traced in the terrain today.

The barrage no longer exists: it was demolished in 1972, so there is no structure to visit. On the Stockstadt side, remains of the old lock chamber can still be made out, and the old course of the Aschaff is partly visible in the terrain. The former Floßgasse was used as a swimming pool in summer.

The former Floßgasse, the 400 m long and 12 m wide raft channel on the right bank, was turned into an open-air swimming pool in the summer months. The old course of the Aschaff, diverted about 2 km into the tailwater for the barrage, can still be traced in the terrain today.