The main anthropogenic impacts on the water resources of the rivers in the Arctic basin of Russia. Five main stages of dams’ construction are outlined. The total morphometric parameters of reservoirs, the total loss of water for dead storage filling and additional free-water-surface evaporation since the early 1940s, and the degree of regulation of the river flow are estimated. It is shown that the reservoirs had little effect on the annual river runoff of the entire Arctic basin. Much more significant was the impact on its intra-annual distribution, especially in the Yenisei basin. The effect of water supply intake on the annual flow of the Arctic basin is relatively small as well. Most of the water supply intake and irrecoverable water withdrawals corresponds to Russia, but the aggregate share of Kazakhstan, China and Mongolia is also significant. Currently there occurs a significant decrease in water abstraction and non-recoverable water discharge in the Arctic basin compared to the level of 1990. It is suggested that indirect anthropogenic impacts (measures of rain-fed agriculture, forestry, including forest fires of anthropogenic origin, and urbanization of the territory) influence the runoff in different directions and their impact is mutually compensated. Water consumption and total water losses due to the combined effect of reservoirs and water consumption have also been calculated since the early 1940s till the present. As is the case with some of these impacts, their total impact on the runoff of the Arctic basin is small, but this effect can be significant in a number of areas, mainly located in its southern part. It is shown that the main negative result of anthropogenic impact is the pollution of rivers and water bodies which is especially significant in the Ob basin. The dynamics of water quality in the largest rivers over the past decades is shown, indicating that it remains unsatisfactory.
