Water Consumption and Water Discharge in the Volga River Basin and Their Impact on Water Quality

The purpose of the study is to assess the change in the volumes of water consumption and wastewater disposal in the basin of the Volga River and its main tributaries in the 1990–2021 period due to changing conditions, as well as their impact on water quality. The data of Federal Agency for Water Resources on various water management indicators and the data of the automated information system for state monitoring of water bodies were used as source materials. To assess the quality of surface waters, materials from regional environmental departments and Rospotrebnadzor were involved. The data of regional federal state budget institutions were used to assess the state of irrigated agricultural land. It was revealed, that from 1990 to 2021 freshwater intake in the basin of the Volga River decreased by 2.3 times. The water turnover ratio increased from 79.5 to 86.7%. In recent years, an increase in the area of irrigated land has begun. The average daily specific water consumption per inhabitant has decreased in all regions as a result of the introduction of water meters and water-saving equipment in housing and communal services. It was revealed that the share of polluted waters in the total volume of discharged waters decreased from 47.3% in 1990 to 43.4% in 2021, but it increased in the basins of many Volga tributaries. Only every sixth cubic meter of polluted water is now cleaned up to standards. It has been established that the amount of the main pollutants discharged with wastewater has decreased ten times over the 1990–2021 period. Although there has been a significant increase in the capacity of treatment facilities over the years of the federal project “Improvement of the Volga” (2019–2021), six of the 12 most important substances have seen an increase in pollution over this period. Despite a decrease in the controlled mass of incoming pollutants, there is generally no improvement in surface water quality, which indicates an increase in pollution from diffuse sources and, possibly, bottom sediments.