By the end of this year, the Olkusz Forest District (Lesser Poland) has extended the ban on entry to forest areas at risk of sinkholes occurring in connection with the mining activities of the former zinc-lead ore mine “Olkusz-Pomorzany”. The ground has collapsed dozens of times in the area.
Pursuant to the decision issued by the forester of the Olkusz Forest District, forest areas covered by the entry ban have been designated in 16 areas in the Pomorzany and Żurada forest districts, located in the communes of Bolesław, Olkusz and Klucze. There is destruction of trees and degradation of the forest undergrowth caused by sinkholes, as well as progressive flooding and ground erosion. These areas are marked with no-entry signs.
The introduced entry ban is valid until the end of this year, with the possibility of shortening or extending its validity period.
Sinkholes in Olkusz
The sinkholes appearing in the areas of these communes are the result of former mining activities conducted by the “Olkusz-Pomorzany” zinc-lead ore mine belonging to Zakłady Górniczo-Hutnicze “Bolesław” in Bukowno.
Mining in this mine ended in 2020, and then the mine drainage pumps were turned off. In 2022, ZGH “Bolesław” established a special team for monitoring potential sinkholes to monitor areas after cave-in mining in its former mines.
The mayor of Bolesław, Krzysztof Dudziński, told PAP last year that earth sinkholes are nothing new in the commune and have been appearing for several dozen years. He admitted that in recent years, after the closure of the mine, the phenomena had intensified, but they occurred in forest areas.
In mid-February last year, a sinkhole related to the activities of ZGH “Bolesław” appeared several meters from the newly built Bolesław bypass. The hole is about 8 meters in diameter and about 5 meters deep. The Road Authority in Olkusz decided to temporarily close the bypass to traffic. Less than a month later, a second sinkhole occurred on the other side of the road.
Main photo source: Olkusz Forest District