The Free State of Bavaria, represented by the Water Management Office of Munich, is planning the construction of a fish hiking aid in the form of a technical slot pass (target fish species grayling) at the outlet of the Schleifermoosach from the Herrenmoosach in the center of the city of Freising. Already in 2017, the approval for the approximately 35 m long fish hiking aid was granted.
In the spring of 2020, Tractebel Hydroprojekt GmbH was commissioned by the Munich Water Management Office to carry out the implementation planning, prepare the tender documents and participate in the award process (object planning LP 5 to 7 and structural design LP 4 to 6). Due to necessary revisions and updates, partial services of the object planning LP 3 as well as the structural design LP 1 to 3 were subsequently provided.
The fish hiking aid, which will be located in the area of a green strip between the banks of the Schleifermoosach and a public footpath and cycle path (Fürstendamm), was designed as an open reinforced concrete trough, which is bordered on both sides by a row of sheet piling walls. The partition and guide walls for the 11 basins are designed as wooden structures, which are attached to steel rails on the side concrete walls. The reinforced concrete sole of the construction is covered with water ecologically suitable substrate. Dam beam closures in the surface and underwater allow access to the system in the event of revision.
The fish ascent system will be carried out under a bridge structure for footpath and cycle path traffic on Fürstendamm, which will also be newly built. The bridge structure is planned by another engineering office.
The project was put out to tender at the beginning of 2021 and the construction work was awarded at the end of March 2021. Construction is scheduled to begin in mid-May 2021. The expected construction time is about 8 months.
In order to determine the construction times, the prescribed closure times on the rivers had to be taken into account. For example the sheet piling work on the water side as well as the construction of the shut-off catch dam in the upper water can only take place from June 2021.
In the upcoming construction phase, Tractebel Hydroprojekt will carry out the local construction supervision as well as the safety and health coordination (SiGeKo).
Matthias Feldmann – Munich