Undertakings review of the ecological condition improvement in the Zdworskie Lake

The paper presents restoration work conducted in Zdworskie Lake after ecological disaster. Reparation work were concentrated on restoration of water supply and chemical quality in the lake. Increasing of water supply were achieved by constructing: broad-crested weir on the outfl ow for rising up the water table, bentonite structure for fi lling the riverbed of the main infl ow, artifi cial alimentation by connecting Dobrzykowski canal with the lake. Improvement of the chemical quality of the water should be achieved by: removing macrophytes biomass, placing bales of barley straw around watering-places, constructing fl oating containers with macrophytes, phosphorus inactivation in the sediments, biomanipulation using the Zebra mussel Dreissena polymorpha