Vráblíková and Wildová in a 2020 Springer book, Assessment and Protection of Water Resources in the Czech Republic , Lake Most was made by flooding a former coal quarry, and the filling was completed in 2014, according to a chapter by Vráblík. Some places often get a second life. In the north of the Czech Republic, a coal mine got one too. A whole town was torn down to reach the coal.
Today, people can swim in a lake in the same spot.
Mining there ceased in 1999. Lake Most covers a little over 300 hectares (roughly 760 acres). In some parts it is about 70 to 75 meters (roughly 230 to 245 feet) deep. The project cost around 2.5 billion Czech koruna and is one of the largest pit lakes in the country. In a 2025 study published in Environmental Monitoring and Assessment , researchers analyzed four lakes that were used for mining activities in the past in the Czech Republic: Medard, Milada, Most, and Barbora.
Water chemistry was mostly within acceptable limits, according to this study. In the 1970s and 1980s, the old town of Most was demolished to make space for the Ležáky brown coal (lignite) mine. What was left was a huge hole in the ground. The town church was moved to a new location and is still standing by the lake. Visitors can use its beaches, and more than two dozen bird species nest in the area. Researchers checked the living organisms present in the lakes, as well as their chemical composition. The team found diverse microbes and plankton, and the mix changed with the seasons, which suggests the lakes are still developing. Sulfates and dissolved solids went over the threshold at Medard and Milada, and one hydrocarbon measure, called C10 to C40, went over at Lake Most. That could be a good reminder that a young lake needs to be tested regularly. Lake Most is unlikely to solve all problems. Coal has left its stamp in this area, and the lake is young. But this shows how communities could take back their land that was once only good for digging. This could be a story worth watching for those who have grown up hearing about coal and climate change.
