The object of the study is a storage facility for liquid mineral waste obtained from the processing of ore rocks. The water in the storage must be at current design levels, complying with the requirements of alluvial beach dams of sufficient length. At the same time, due to natural (rainstorms, floods) and technical (discharges of industrial waters) reasons, the degree of water saturation of the tailings pond can reach, and sometimes exceed, the maximum design value. The main goal of the study was to assess the influence of the degree of water filling of the liquid mineral waste storage facility on the hydro geo mechanical state and filtration and deformation stability of the enclosing dam. The research method consisted of constructing a 3D model of a fragment of a storage facility at one of the mining enterprises in the Kola region, and hydro geo mechanical modelling of the emerging filtration and deformation processes at different water levels in the tailings storage tank. As a result of the study, calculated indicators were obtained characterizing the resulting hydro geo mechanical state of the enclosing dam depending on the degree of water filling of the tailings storage tank. An approach is proposed to the formation of engineering solutions to ensure filtration stability and mechanical strength of dams enclosing a storage facility for liquid mineral waste, the water level in the reservoir is highly dependent on natural and man-made influencing factors.