Justification of environmentally safe water levelin “Novohrodivska 2” minefor protectingadjacent areasfrom flooding

Purpose. Predictive estimation of changes in hydrodynamic conditions of “Novohrodivska 2” mine during its closure and operation of geothermal systems with evaluation of a required capacity of drainage systems capable to prevent flooding in the areas adjacent to the mine. Methods. The total mine water inflow was calculated using the analytical relations of geofiltration and empirical dependencies while considering the rate of mine water level increase during the previ-ous stages of flooding and hydrodynamic connections with mine workings of a neighboring mine named after D.S. Korotchenko and “Novohrodivska 1-3” mine as well as the volume of mined out space and existing geological and structural tectonic faults. Findings. The total water inflow to the “Novohrodivska 2” mine calculated according to different approaches varies in a range of 2000–2200 m 3 /day depending on the inflow from neighboring mines, infiltration withing the range of 30 to 50 mm/year and the inflow from the upper aquifer. This inflow should be completely pumped out by drainage systems and discharged into the hydrographic network beyond the mine catchment area in order to maintain the hydrodynamically and environmentally safe level of +185 m during mine closure and the operation of geothermal systems. Originality. The suggested new comprehensive approach to evaluate the total inflow during mine closure allows adequate consideration of hydrodynamic conditions in this area, geological and hy-drogeological structure and the impact of various natural and technogenic factors. Practical significance. The data obtained during the calculations of water inflow to the “Novohrodivska 2” mine will be used in estimation of a required capacity of drainage systems, which allow prevention of flooding and avoiding adverse physical and geological phenomena in the areas adjacent to the mine. In addition, the calculated values of water inflow are expected to be used in determining technological and economic indicators of geothermal systems.