A lot of water has flowed down the Isar since the weir system in Großhesselohe went into operation for the first time. That was in 1906, and more than a century later, the building is now being extensively renovated with the aim of improving ecology and flood protection. The Department for Climate and Environmental Protection of the City of Munich has now given the go-ahead for the measure with the approval of the plan.
According to a press release from Stadtwerke München (SWM), work on this should begin as soon as possible in 2023. In the end, the new system should automatically control the minimum water discharge into the Isar, a new fish ladder should improve the passage for aquatic life and at the same time the ecological networking of the Isar and the works canal should be maintained. Operational safety, water protection and occupational safety would also be improved.
Since 2008 there have been several replannings
The replacement building should be an optimal ecological, operational and flood protection solution for the next hundred years, write SWM, which has been involved in the construction project since 2008, when they worked out an “Isar plan” with the state capital and agreed on the further development of the system had. Several conversion alternatives and even a dismantling of the weir system were then examined before the replacement building was finally applied for in 2014. After the approval process, it became apparent that the originally planned project could not be implemented. As a result, the planning was revised in consultation with the specialist authorities, so that the focus was now on flood and flotsam management and on ecological continuity for the entire spectrum of species occurring there.
But that was not the end of the planning, because in the course of the approval process that began in early 2021, the facility was classified as a monument – the plans therefore had to be changed again. The parts of the facility that are worthy of protection would now be preserved and brought into line with the requirements of a modern weir system, write the SWM. The approved plans would also be supported by the three nature conservation associations in Bavaria with the most members, the state association for bird protection, the association for nature conservation and the state fishing association, which are now demanding timely implementation.