
Christened "Kaiman": The Ruhrverband presented its new mowing boat. Also present (from left): Antje Nielinger-Teuber, Simone Raskob, Markus Rüdel, Hans-Walter Fink, Mayor Thomas Kufen, Boris Orlowski, Matthäus Schallenberg and Prof. Christoph Donner. Photo: Ruhrverband
"Kaiman" to contain elodea in Baldeneysee
Essen, Baldeneysee, July 16, 2025: The Ruhrverband presented a new mowing boat in Scheppen harbour on Wednesday: "Kaiman" will be used to combat the aquatic plant Elodea in Baldeneysee in the future. Together with another boat already in useBaldeneysee.Ruhr reported), the new boat will strengthen the maintenance measures on the lake. The naming ceremony was attended by Lord Mayor Thomas Kufen, Ruhrverband boss Professor Christoph Donner, Weisse Flotte Baldeney GmbH Managing Director Boris Orlowski and IG Baldeney Chairman Hans-Walter Fink, among others.
Aliens in our ecosystems
Elodea, originally from North America, has spread to the Ruhr region and increasingly poses a challenge for water sports and recreational use. The good water quality, the result of decades of improvements in wastewater treatment, greatly favors the lush plant growth. "The name 'caiman' was chosen deliberately," explains Professor Donner. "It is intended to indicate the ecological change caused by invasive species. Caimans are themselves aliens in our ecosystems - just like the Elodea."
Coordinated measures for clean waters
The city of Essen, Ruhrverband, IG Baldeney and Weisse Flotte Baldeney GmbH have been working closely together for years. The Ruhrverband provides the mowing boats, Weissee Flotte Baldeney GmbH takes care of their personnel and deployment, while IG Baldeney coordinates the areas to be mowed. In addition, a loading barge from the Düsseldorf district government is used to pick up the plant material directly on the water and increase the efficiency of the work. "Regular mowing is essential for sporting events and training operations," emphasizes Mayor Kufen. " Baldeneysee is not only a place of recreation for many Essen residents, but also their sporting home." Without mowing work, the operation of the Weisse Flotte Baldeney GmbH passenger ships would only be possible to a limited extent or not at all.
Growth with risks - Elodea remains a challenge
Although the aquatic plant provides a habitat for numerous aquatic inhabitants, the massive biomass poses problems for users. The "Elodea II" research project showed that alternatives such as mechanical soil cultivation or competitive planting proved to be less effective. Mowing is the only practicable measure for the time being. During test runs in June and July this year, the yield has so far remained low. Nevertheless, experts warn that in the current weather conditions - lots of sunshine, high temperatures and clear water - plant growth could surge at any time. Elodea can grow up to 20 centimetres per day.
Looking back at 2024: record year for plant growth
In summer 2024, over 510 tons of elodea were removed from the Baldeneysee removed - a figure that was only exceeded by the hot summer of 2018. More than 50 container loads were needed to remove the cuttings. The current preparations are intended to ensure that the lake remains usable even with increasing vegetation and Kaiman should help effectively.







