Lake recult. in Gniezno - Recultivation of Jelonek and Winiary lakes in Gniezno by inactivation of phosphorus in bottom sediments

The project targeted lake recultivation in Gniezno by deactivating phosphorus in bottom sediments using coagulants, thus protecting inland resources on surface waters in line with the Water Framework Directive. Upon conclusion, the project had basically reached its objectives and the quality of water improved substantially, making it possible to use the lakes for recreational activities. The reconstruction of the degraded banks not only protected the water from infiltration of pollutants from storm water but also increased landscape value of the lakes. Further, the biotope quality improved and the biocenosis in the lakes revived thanks to macrophytes plantation and renewal of fish stocks, contributing to the reduction of the blue-green algae blooming and to a limited share of algae in the phytoplankton. Activities managed to reduce phosphorus and chlorophyll contents significantly, and enhanced water transparency