In order to use water resources as a need for drinking water; there are permissible limits of the national and international standards for the physical properties of water, and some dissolved parameters in the water. Environmental monitoring should be carried out by regular measurement of these parameters. A large geographical area of Siirt Province located in the southeast of Turkey is mountainous and so rugged and, it may be characterized as a water-rich region. Hesko Spring stands within the boundaries of Siirt Province and supplies a significant part of the water demand of the province. There is not any study in the literature about this water resource which is very important for the province and also, no previous analysis has been made on it. Although the transportation is very difficult, and the land remains in the security zone, it has made the analysis of this spring impossible. Due to these features, Hesko Spring can be defined as a 'hidden spring'. In this study, the chemical analysis of the water samples which were taken during the spring season of 2019 by performing fieldwork were carried out in the laboratory medium. At the end of this study, the results of the chemical analysis of this hidden spring were evaluated.