The natural factors influencing the water quality of water resources are theoretically considered to be stable. However, it is evident that the climate patterns of Earth are changing. Climate, as a potential indirect natural factor in the formation of the chemical composition of natural waters, not only leads to obvious hydrological changes but also inevitably leads to hydrochemical changes. The quality of drinking water sources may be compromised by increased sediment or nutrient inputs, as well as changing in mineral composition water. Long-term observations were shown that precipitation and natural flow of Voghji river in the reference point were decreased by 18% in 2007-2020 compared with the 1961-1990 baseline period. At the same time, significant changes in the ratio of elements of the mineralization regime were observed in the river. As a result, the nature of the water of the Voghji River gradually becomes strongly hydrocarbonate-sulfatecalcium ։ the difference in the concentrations of the main ions compared to the baseline period is 4.7-13.6%. If in the baseline period the ratio of calcium and total sodium and potassium concentrations was almost equal, then according to long-term observation data the increase in calcium and sodium, as well as a sharp decrease in potassium are recorded.