Construction of dams as an abnormal structure in the riverbed, although it is considered as a management and planning tool, but its lack of management and quantitative and qualitative monitoring can lead to environmental problems. Seymareh Dam in Karkheh catchment was flooded in 2011 with the aim of generating hydropower, increasing the regulation power of downstream dams and flood control. According to the water processes in the dam water resources network and quantitative and qualitative evaluation of the role of dewatering, quantitative and qualitative sampling was performed before and after the construction of the dam over a period of 10 years. The study of qualitative results showed that the role of geological formations, especially Gachsaran and Asmari formations is effective in increasing the concentration of solutes and dissolution and the left bank springs have more qualitative changes due to the greater thickness and volume of Gachsaran and Asmari formations. On the other hand, the correlation between reservoir water level during dewatering and quality parameters showed that dam reservoir dewatering had the greatest impact on the right bank springs and had more correlation in changes. The results of qualitative analysis in Seymareh river also showed that the anomaly in the quality parameters of R4 station due to two factors of rainfall in spring and the addition of water leaving the power plant has been effective in changing water quality.