de.wikipedia.org/wiki/Helenesee

The quoted sentence says bathing in the lake is supposed to remain prohibited until well after 2030. Current official sources contradict that blanket claim.

In a June 11, 2026 press release, the City of Frankfurt (Oder) explains that the LBGR had already lifted the closure for a 350-meter section on the east shore in 2024. The city then states: "Auch wenn es seit zwei Jahren erlaubt ist, vom Ufer des vom LBGR freigegebenen Abschnitts aus den See zu betreten" — i.e., it has been allowed for two years to enter the lake from that released shore section. The same notice says the city issued a new general order specifically to regulate risks for people using the lake "z. B. beim Baden, Tauchen oder Bootfahren". That means bathing is being regulated there, not totally forbidden everywhere in the lake.

The LBGR's own page on restricted areas likewise says that in July 2024 the closure of a defined area on the east shore of the Helenesee was lifted. So while most shore and shallow-water areas remain restricted and the released section is not an official bathing beach, the article's categorical statement that bathing in the lake is to remain banned until after 2030 is no longer correct.

In short: continued large-scale closures and delayed full rehabilitation are real, but a total lake-wide bathing ban until after 2030 is false because a released east-shore section has already allowed legal water access since 2024.

This sentence states a specific cause for the March 2021 slope failure: lowered water level caused by a low groundwater table due to missing precipitation. That is not how the official and judicial sources describe the event.

A 2024 LBGR presentation on the geotechnical investigation says the cause was "Verflüssigung und Ausfließen von locker gelagerten Sandauffüllungen" in the beach/shore platform at the northeast shore, i.e. liquefaction and outflow of loosely deposited sand fill. It further says the resulting flow slide was triggered by dynamic loading, possibly connected with wind waves and ice drift.

A 2021 decision of the Verwaltungsgericht Frankfurt (Oder) likewise states: "Als maßgebliche Ursache für derartige Ereignisse ist die Verflüssigungsneigung lockerer gelagerter und wassergesättigter Massen anzusehen." In other words, the decisive cause identified in the record is the liquefaction susceptibility of loose, water-saturated masses in the old mining deposits.

Water-level changes were discussed in the proceedings, but the available official material does not support the article's categorical statement that the slide was caused by low groundwater due to lack of rainfall. At most, water level is treated as a contributing hydrogeological condition; the established primary mechanism is geotechnical liquefaction / flow failure of loose fill material.

This sentence specifically describes the source mine as a "Braunkohletagebau" running from 1906 to 1958. Official mining-history sources from Brandenburg contradict that dating.

The LBGR's Helenesee information page says: "Der Tagebaubetrieb begann 1940 mit den Sümpfungsarbeiten für das Teilfeld Helene Nord. Nach der Abraumbewegung 1943 im Teilfeld Helene Nord wurde ab 1944 Kohle gefördert."

A 2024 LBGR geotechnical presentation gives the same timeline in more detail: 1940 start of dewatering, 1943 beginning of overburden removal, 1944 first coal extraction, 28.03.1958 end of coal extraction, and 30.06.1959 the official end of lignite mining in the Brieskow-Finkenheerd area.

So the mine that produced the rest hole later filled to become the Helenesee was not an open-cast lignite mine running from 1906. If 1906 refers to earlier mining activity, that would concern earlier mining history, not the Tagebau Helene that created the lake. For the open-cast mine named here, the article's 1906 start date is incorrect.