This article presents modern data on the chemical and gas compositions, as well as the contents of the stable isotopes of oxygen, hydrogen, carbon, and sulfur, in the natural mineral waters of the Essentuki field. A detailed study of the geological and hydrogeological features of the water circulation territory, their macro-component compositions, the contents of organic matter in the water, and the temperature conditions and values of δDSMOW, δ18ОSMOW, δ13СDIC, δ18ОDIC, δ34SVCDT, δ13CCO2, δ13CCH4, and δ15N revealed the genesis of the aqueous, gas, and salt components of the natural mineral waters of the Essentuki field. It was established that all natural mineral waters of the Essentuki field are infiltration meteoric waters. The heterogeneous component composition of the natural mineral waters circulating in various aquifers represents the features of the lithological composition of the water-bearing rocks, the degree of openness or closeness of faults, and the intensity of reactions in the water–rock–gas–organic matter system.
The potential improvement of the reliability of process water supply system is discussed for the case of an important power facility with the use of combined water intake systems. Hydrological simulation is used to determine the deficiency periods of surface water resources and, accordingly, the period of involvement of subsurface compensation water intake. A hydrodynamic model is used to predict the damage to surface runoff caused by the operation of the groundwater intake. The results are used to prepare an operations schedule for the management of combined water intake system.
Issues of balance substantiation of water withdrawal and long-term development of groundwater deposits are considered. It is proposed that the balance structure of water withdrawal is typified according to the degree of involvement of the available (natural) and attracted resources. It is shown that the forecast calculations in the case of a partially active balance structure should take into account seasonal variations in the surface and subsurface water runoff.
