Empirical study of the isotopic features of river runoff were conducted at three hydrological posts in three different river basins: the Zakza river in the center of East European Plane (southwest of Moscow), the Dubna river (north of Moscow) and the Sosna Bystraya river in the south of central region.

Empirical study of the isotopic features of river runoff were carried out at three hydrological posts in 3 different river basins Eastern Europe. Samples of river water, groundwater and precipitation for the October 2019–October 2021 were collected at weekly intervals. A significant supply of melted snow during spring freshet was the key factor influencing water regimes for these three river basins; varying degrees of anthropogenic flow regulation are also presented.