As a result of the Russian armed aggression, Ukraine has lost almost a third of its accumulated fresh water reserves worth more than USD18 billion. It has caused a loss of access to quality drinking water for 6 million people in Ukraine and more that 13 million people have a limited access to water for satisfying sanitary and hygienic needs. The situation is complicated due to the destruction of the Kakhovka hydroelectric power station dam which has led to a large-scale man-made disaster, severe negative environmental and socioeconomic consequences, the beginning of natural-climatic transformations of the drained water reservoir. The article presents comprehensive research of the state of the Kakhovka Reservoir functioning before and after the destruction of the hydroelectric power station dam on the basis of the actual facts and the results of decoded satellite imagery of Sentinel 2, Sentinel-3 and Landsat 8–9. It was found that the water reservoir drainage has caused disruption of microclimatic conditions, an increase in the air temperature by 2.0°С and more, accelerated evapotranspiration by 1.41–2.04 times, exacerbation of water scarcity in 58.2% of the territory of the drained water area and in the adjacent territories. About 52.0% of the territory of the drained water reservoir has stressful conditions of natural-climatic functioning. The obtained results confirm that the formed aboveground plant biomass of bottom landscapes is not capable of creating appropriate microclimatic conditions which existed in the water area of the Kakhovka Reservoir.