Repair work on the balancing pond at the Möhne Dam continues

As in the previous year, the Ruhrverband will drain the balancing pond below the Möhne Dam in the last week of August 2026; this is expected to continue until around mid-October. The reason for this is the continuation of the extensive repair works, planned to run over several years, which are necessary to ensure the long-term safe and reliable operation of the Möhne Dam and its hydroelectric power stations.

As was the case last year, several measures will be grouped together and carried out within a concentrated construction period. Among other things, the conical nozzle on bottom outlet II will be removed, as was the case last year with bottom outlet III. To minimise damage to the existing structure around the conical nozzle, the removal will once again be carried out using a complex concrete-cutting and ultra-high-pressure water jet process. Next year, when the balancing pond is lowered again, new conical nozzles will be fitted to both bottom outlets. The necessary anti-corrosion work on the bottom outlet pipework was completed in the course of this year. 

Minor joint-repointing work is also required at the right-hand foot of the dam, and the inlet where the Westricher Bach flows into the balancing pond still needs to be completed. On the water-facing side of the dam, inspection hatches will be fitted to two bottom outlet inlets as part of diving operations. Under the protection of these hatches, inspection work and the repair of a hydraulic cylinder will subsequently be carried out.

In the main power station, the steel armour of the runner wheels in the outlet area of the two turbines is being given a new coating, and the end section of the power station penstock is being rebuilt. This work at the main power station is a prerequisite for the comprehensive inspection and, where necessary, repair work on the power station penstock, which is scheduled for next year or the year after.

Work will also have to be carried out again at the auxiliary power station this autumn, as the repair of the turbine inlet gates has proved to be more complex than was foreseeable last year. Work is taking place on the minimum water discharge pipe, the wing walls and the hydraulic cylinder of the weir gate, as well as the screen system leading to the turbines.

The Ruhrverband expects the extensive construction work to be completed by mid-October. If everything goes according to plan, the refurbishment – scheduled to take several years – will have made significant progress by then.

Restrictions for the public: During the works, construction site traffic is to be expected, particularly on the south side of the balancing reservoir. The paths around the pond will remain largely open to the public – apart from short-term closures for crane operations or similar work. The crest of the Möhne Dam will also remain accessible.

Important: Entering or driving on the drained pond area is strictly prohibited. These areas pose considerable dangers. The Ruhrverband has put up appropriate signage to warn of the risk to life. The balancing pond is also a bird sanctuary. For this reason alone, people should refrain from entering this area unnecessarily and thereby disturbing the birdlife.