Reconstruction of Ancient Lake after Peat Excavation—A Case Study about Water Quality

According to regulations in some European countries, peat is treated as a fossil fuel or soil for mushroom horticulture and its management is subject to the law for mining activities. As a result of the exploitation of peat bogs, the cutaway or pit lakes remain, which when properly prepared can be local water resources. Such post-peat water bodies can be used for recreation and they can be particularly important in areas struggling with water deficiency in the rural landscape. Maintaining good water quality in such reservoirs requires a number of preparatory works, including the removal of the remaining organic matter that would rest at the bottom of the new pit lake, affecting the water quality. Studies of water quality and aquatic plant communities in the studied post-peat lake were carried out during the period 2012–2014 in order to determine the changes in water quality and the usefulness of water for cyprinids. Aquatic plant communities identified in the reservoir showed a simplified species composition, characteristic of initial communities, and they occupied small areas in the water and on the banks. It has been shown that water quality parameters of the studied water body were stable and corresponded to thresholds established for cyprinids.