turbine plant of the former Haas weaving mill

The turbine plant of the former Haas weaving mill in Ottenbach is an industrial heritage site on the Reuss river in the canton of Zurich, in the Knonauer Amt district. A small hydroelectric station once powered the A. F. Haas & Co. silk weaving mill. Today it works as a museum installation inside a riverside nature reserve.

What is this place?

The ensemble includes the old mill buildings, the turbine house, the boiler house and the hydraulic works. The Zurich heritage inventory describes it as an outstanding witness to the region's industrial history. Water power was used on the site as early as 1836, while the equipment you can see now dates from 1909 to 1920. Around 1920 the mill was electrified, and a newer, stronger turbine with a generator took over the looms.

What will you see?

The centrepiece is a Francis turbine rated at 61.8 kW, the third in a series of ever larger machines installed here. The system also includes the headrace and tailrace canals and a 200 m overflow weir across the Reuss, which is protected as a monument. You can follow the path from river to machine and see how water became factory power, in a plant that has largely kept its original character.

How did it become a museum?

The mill wove fabric until 1970, after which the buildings housed a textile business. In 1977 the canton of Zurich bought the plant as part of its Reuss bank protection programme. The 2005 flood badly damaged parts of it, and the water structures were repaired in 2010 and 2011. Since 2013 an association has run the turbine and looked after flood protection.

How to get there and when to go

Ottenbach lies in the south-west of the canton, about 20 km from Zurich and close to the Aargau border. The site sits by the river at 47.2799 N, 8.3974 E. Check opening dates with the museum operator before you travel, as the turbine is mainly open on set days. Late spring and summer are pleasant, and the visit pairs well with a walk along the Reuss.

Frequently asked questions

Is the plant a protected monument?

Yes. The cantonal heritage service looks after the complex, and the weir is listed as a monument in its own right.

Who owns it?

The canton of Zurich, since 1977. An association has handled operation and flood protection since 2013.

Is the mill still working?

No. Weaving ended in 1970, and the buildings now host a textile trade business.

Why visit?

It is a rare, well-preserved factory power station in a scenic riverside reserve.