Jettenbach I Run-of-River Plant

The Jettenbach VERBUND power plant is a dam on the Jettenbach and is located in the municipality of the same name in Upper Bavaria.

*Source: ENTSO-E Production 2017

The Jettenbach I power plant was completed and opened in 1924. It dams the Inn over a distance of 8 km. A single-blade Francis turbine processes the minimum water flow rate of 5 m3/s and generates an annual average of approx. 1 GWh of electricity.

In the Jettenbach storage area, just before the weir, some of the dammed water is passed through a contactor system into the Innwerkkanal and from there to the Töging run-of-river power plant.
Weir system: The weir system has 6 openings with a clear width of 17 metres. The weir is closed with double gates that are hung on winches with link chains. The drive unit is housed in a reinforced concrete superstructure clad in wood as a weir construction. On the left, connected almost perpendicularly, are 21 channel inlet openings with a width of 5.6 metres each, which can be closed by 2 sluice boards each. In the building on the right is a small power plant that processes the remaining minimum water flow rate of 5 m³/s with a single-blade Francis turbine. Road bridges pass over the weir system and the inlet structure. The weir is designed for 4,000 m³/s, the highest known water flow rate at the time was 2,900 m³/s and it was built in 1899.

Innwerkkanal between Jettenbach power plant and Töging power plant: The water held back at km 128 by the Jettenbach weir is fed into the canal through the sluice system. It was the first weir structure on the Inn in Bavaria in 1923. The 20 km-long headrace channel begins with a 300 metre-long and 125 metre-wide cleaning basin, in which the material carried along should settle when the flow velocity reduces. To increase leak-tightness and reduce roughness, the canal, which narrows after 6 km from 52 metres to 30 metres in width at the surface and 8 metres in depth, was lined with concrete. The average water velocity with the least possible loss of gradient is 2.0 m/s.