Turbine plant of the former Haas weaving mill, Hydroelectric power station in Ottenbach, Switzerland

The turbine plant of the former Haas weaving mill is a power generation facility built around a Francis turbine system operating at 387 meters elevation. The structure retains its original technical components and demonstrates the engineering approach of an early hydroelectric installation.

The facility opened in 1920 as a technical upgrade to the silk weaving operations of A.F. Haas & Co, marking the shift from mechanical to electric power. Its construction reflected a broader movement to enhance craft production with modern mechanical systems.

The plant powered the looms of A. F. Haas & Co., the silk and decorative fabric weaving mill that took over the business during the global economic crisis and produced here until 1970. The company then turned to textile trading as Haas Shopping. Inside, the Art Deco-style switching wall with electromechanical measuring devices from Trüb, Fierz & Co. once controlled the lighting of the weaving rooms.

The plant stands by the Reuss in the Bibelaas reserve, which the canton of Zurich bought in 1977 to protect the river banks. The 200-metre side weir, the longest of its kind in the canton, feeds the headrace canal through four gates; the gravel trap is opened once a year for a few days. The canal and weir were repaired in 2011/12 after the floods of 2005 and 2007.

The 200-metre side weir is the longest of its kind in the Canton of Zurich. Its four gates control how much Reuss water enters the headrace canal, and a gravel trap is opened once a year for a few days to flush sand and gravel out of the weir channel.