Lohsa I reservoir, reservoir in Lohsa, Saxony, Germany

Lohsa I reservoir is a large body of water located near the town of Lohsa in Saxony. The water is held back by a dam and spreads across a wide surface surrounded by flat fields and scattered woodland areas.

The reservoir was created between 1967 and 1972 by flooding the former pits of the Werminghoff II open-cast lignite mine, later renamed Glückauf II, which operated from 1933 to 1960. The remaining pits, the Mortkaer Restloch and the Friedersdorfer Restloch, were linked by a canal. Bank consolidation work at the Silbersee began in March 2011 and lasted until spring 2025.

Walking and cycling paths run along the shores of the reservoir, making it easy to explore the area on foot or by bike. The open landscape and quiet surroundings make it a straightforward spot to enjoy outdoor activities and watch local wildlife.

The reservoir flooded the former Werminghoff II (later Glückauf II) lignite open-cast mine, worked from 1933 to 1960, between 1967 and 1972. Its two residual pits, the Mortka and Friedersdorf lakes, are linked by a canal; the Mortka lake is used only for fish farming. In 2024 over 190 floating solar modules were installed on the Mortka lake as a research pilot.