Reduction in the quantity of water in the Inn diversion route at Jettenbach-Töging
19.02.2021Töging am Inn
Scientific investigations in the period from 22 February 2021 to probably 13 March 2021 require a temporary reduction in the minimum flow of water in the original watercourse.
The licence for renovating the Jettenbach-Töging power plant includes ecological improvements in the area of the original course of the Inn at Jettenbach-Töging. The Institute for Water and Environmental System Modelling at the University of Stuttgart has therefore been carrying out a study into the morphological situation of the waterbodies on behalf of VERBUND Innkraftwerke GmbH and in close cooperation with the water management board in Rosenheim since 2019. This will require a temporary reduction in the minimum flow of water in the diversion route from 22 February 2021 until probably 13 March 2021.
Part of this study should also involve checking the extent to which the formation of small structures or bedload management based on waterbody ecology can achieve an improvement in the substrate quality and thus also the suitability of the habitat for species of fish that spawn in gravel. Ultimately, this should create a good ecological situation in accordance with the EU’s Water Framework Directive.
Over the course of the study, extensive field surveys, hydrodynamic and hydromorphological modelling, and habitat suitability modelling will be carried out, in order to carry out an analysis and assessment of the current status and the planned improvements. The focus of the currently planned field surveys should once again examine in detail existing gravel banks in the original route for sediment characteristics and possible clogging (colmation). The already completed addition of gravel and sediment as well as further excavations for loosening up the gravel banks will also be investigated.
In order to carry out these field surveys, the minimum flow of water will be reduced from 22 February 2021 until probably 13 March 2021, in order to ensure better accessibility to the waterbody and to enable investigations in the spawning zones. The necessary permits for this are available.
The investigations should also enable the subsequent examination of possible effects caused by a small, non-dangerous winter flood, which will be simulated for about one day. To do this, the flow rate will be slowly increased to 130 m³/s, although there is no need for concern about a sudden rise in the water level.
The project to renovate the Jettenbach-Töging power plant is connected with ecological improvements in the area of the Inn. The natural section of the Inn between Jettenbach and Töging, the so-called original Inn route, should in future benefit from scientifically based management of the spawning grounds and sediment. To create the necessary scientific basis for this, corresponding investigations are required, which will be carried out by the University of Stuttgart in cooperation with Karlsruhe University of Applied Sciences.
Part of this study should also involve checking the extent to which the formation of small structures or bedload management based on waterbody ecology can achieve an improvement in the substrate quality and thus also the suitability of the habitat for species of fish that spawn in gravel. Ultimately, this should create a good ecological situation in accordance with the EU’s Water Framework Directive.
Over the course of the study, extensive field surveys, hydrodynamic and hydromorphological modelling, and habitat suitability modelling will be carried out, in order to carry out an analysis and assessment of the current status and the planned improvements. The focus of the currently planned field surveys should once again examine in detail existing gravel banks in the original route for sediment characteristics and possible clogging (colmation). The already completed addition of gravel and sediment as well as further excavations for loosening up the gravel banks will also be investigated.
In order to carry out these field surveys, the minimum flow of water will be reduced from 22 February 2021 until probably 13 March 2021, in order to ensure better accessibility to the waterbody and to enable investigations in the spawning zones. The necessary permits for this are available.
The investigations should also enable the subsequent examination of possible effects caused by a small, non-dangerous winter flood, which will be simulated for about one day. To do this, the flow rate will be slowly increased to 130 m³/s, although there is no need for concern about a sudden rise in the water level.
The project to renovate the Jettenbach-Töging power plant is connected with ecological improvements in the area of the Inn. The natural section of the Inn between Jettenbach and Töging, the so-called original Inn route, should in future benefit from scientifically based management of the spawning grounds and sediment. To create the necessary scientific basis for this, corresponding investigations are required, which will be carried out by the University of Stuttgart in cooperation with Karlsruhe University of Applied Sciences.
