Mainz digs deep with a 220m Rhine pipeline using innovative drilling
Mainz is set to begin work on a new 220-metre pipeline beneath the Rhine in May. The project will replace an ageing supply and wastewater line that has suffered partial damage. Officials have deemed a full renovation of the existing system too costly to justify. Construction will start on May 11, using a trenchless method called horizontal directional drilling. This technique, a first for Wirtschaftsbetrieb Mainz, avoids digging open trenches and reduces disruption to the surrounding area. The new pipeline will stretch from the Ingelheimer Aue area near Gassnerallee to the sewer network at Mombacher Kreisel.
The pipe will measure 71 centimetres in diameter and be buried up to ten metres below the riverbed. To protect it from damage, the line will sit inside a reinforced sleeve. This design also allows for future repairs without interrupting operations in the nearby harbour basin. Work is scheduled to finish by the end of August 2026, ensuring a long-term solution for the city’s water and wastewater needs.
Once complete, the pipeline will improve reliability for both supply and wastewater services. The protective casing and trenchless installation aim to minimise future maintenance issues. The project marks the first time this drilling method has been used by the city’s utility provider.
