An assessment of the radioecological state of water bodies on the territory of the uranium mining enterprise represented by the decommissioned Almaz Scientific and Production Association (LPO Almaz) uranium mining plant located in the town of Lermontov and in the adjacent residential area was carried out. Water bodies represent a critical factor for characterization of the radiation factor in terms of its impact on the population. After measuring the content of natural radionuclides in water and bottom sediments, the current radioecological state of water bodies as a whole was assessed. The content of natural radionuclides in water was estimated by multiplying the excess of the intervention level for each radionuclide present in a significant amount; for several radionuclides, the summarized ratios of specific activity to the corresponding level of intervention were used. The content of natural radionuclides in bottom sediments was estimated according to the effective specific activity of solid materials. A conservative average annual effective dose potential for the population in the residential area due to water bodies was calculated. Radium-226 was identified as the main radionuclide forming a dose load of internal exposure due to water bodies of the residential area in the immediate vicinity of the decommissioned LPO Almaz plant. Based on this radionuclide, an individual potential radiation risk to public health was calculated for recreational and agricultural modes of water use.