Vortex drop shaft in operation in Muri (BE)
The GDP (General Drainage Plan) of the municipality of Muri b. Bern included various urgent measures for the wastewater network in the Mettlen district. The centerpiece was a double-flow vortex drop shaft, that facilitates a controlled vertical drop of around 15 m in which the wastewater follows a spiral path. The feed line to the vortex fall shaft and the drain to the downstream rain basin were laid in a trench-free microtunneling process. In addition, a new rain outlet and a new relief channel into the Aare were built.
HOLINGER designed and managed this complex project, which was also challenging due to the sensitive environment around that included quiet residential and a busy recreation area as well as a nature reserve. After two years of construction, the vortex drop shaft and thus the whole new sewage network was put into operation.