Irkutsk Reservoir: Construction History and Hydrochemical Studies of Streams and Bays

The formation history of the Irkutsk Reservoir is considered along with its effect on changes in the nearby area and water chemistry. The results of hydrochemical studies, carried out by the authors in 2022 in reservoir bays and tributaries are analyzed and compared with earlier studies. The waters of rivers flowing into the Irkutsk Reservoir were found to belong to sulfate-hydrocarbonate magnesium-calcium type. The chemistry of the waters of rivers, bays of the Irkutsk Reservoir in the key areas, where inhabited localities, cottage settlements, and garden plots are situated, was found to differ from the background chemistry and to be chloride-hydrocarbonate magnesium-calcium. The microelement composition of water in the major portion of the reservoir corresponds to the ranges of the basic concentrations of microelements at the source of the Angara River.