Dürrlohsee, water reservoir in Germany

Dürrlohsee is an artificial reservoir one kilometre south of Mühlhausen in the Upper Palatinate, lying at 415 m on the groundwater floor where the Sulz and Roßbach meet. It measures roughly 0.7 km by 0.4 km, about 0.2 km², and holds some 2 million cubic metres. Its surface drops from a target level of 415.5 m to 407.75 m as water is released to the Main-Danube Canal.

The site originated as a small medieval pond for farming and fishing, then underwent major expansion in the 1980s as part of canal development. Water control systems were installed in the 1990s to support modern canal operations and lock management.

The lake is fenced off and not open for swimming or boating because of large water-level swings and suction hazards. The water level drops from 415.5 m above sea level to 407.75 m when water is released. The outlet channel runs to the canal near the upper head of the Bachhausen saving lock at canal kilometre 115.5.

The lake can supply about 16 lock operations per day without additional water input, with supplies replenished through nighttime pumping during cheaper electricity rates. This intelligent water management shows how one reservoir supports an entire transportation system.