Posted on August 12, 2026
By Jill Grigoleit
Siltation in the Lower Saxony sailing area continues to progress. This is now confirmed by new measurements taken by the Association for the Preservation of Lake Steinhude (VESM): according to these, there are now between 15 and 16 million cubic metres of silt on the lake bed. In the last comparable measurement in 2019, the figure was 14.4 million cubic metres. This means that the volume of silt has increased by around one to 1.5 million cubic metres within seven years.
1,000-kilometre test route
The measurements were carried out from late March to early July 2026. According to the association, just under 1,000 kilometres of survey route were recorded using echo sounders and GPS, involving approximately 1,000 hours of voluntary work. More than 1,100 additional manual control soundings were carried out to verify the results. More than 90 per cent of the control measurements confirmed the echo sounder data. SPE Dredging Solution GmbH, which had already carried out the last survey in 2019, provided the measuring equipment (the same as on that occasion) and analysed the results in the same way as seven years ago to ensure direct comparability. According to VESM, the result is clear: “The dredging carried out in recent years was clearly insufficient. This has exacerbated the problems with the waterway’s usability.”
At the same time, the relevant authorities have, as part of of the new lake development plan A further depth survey was also carried out. They reached a similar overall conclusion: in large areas, the “thickness of the silt layer” had increased. At the same time, there were also areas where less sediment was found. The structure of the deeper channels, known as ‘deipen’, is said to have remained largely unchanged.
Every year, more sludge is added
The real problem, however, becomes clear when looking at the annual figures. According to the state authorities, an estimated 52,000 to 64,000 cubic metres of new sludge is currently being produced at Steinhuder Meer each year. Since 1980, however, an average of only around 30,000 to 40,000 cubic metres has been removed annually. The increase now observed is therefore not surprising. The new Lake Development Plan II therefore aims to take stronger countermeasures in future. In future, dredging is to be based on the actual rate of new sediment formation and carried out specifically where the sediments particularly impair the use and maintenance of the lake. For the time being, however, this simply means that the annual rate of new sediment formation is to be offset. The existing sludge mound, which amounts to up to 16 million cubic metres, would not be reduced as a result.
