The dam of the Fláje reservoir was built from 1951 to 1964. It is 459 m long, 50 m high and at the top 6 m wide. The reservoir is used as a drinking water reservoir for the district of Most. The Fláje reservoir occupies an area of 153 ha. The water comes from a catchment area of about 43 km².
For the dam the village Fláje (German: Flöha, after the river) had to make way, except for six remaining houses. In the surroundings you can still discover remains of the village, which are being reclaimed by nature.
Since 2019 there is an information centre at the dam, which was built with quite a lot of EU funds. The following video was published about its construction: