Water quality of dam storage is highly affected by upstream environment and basin. Regarding other conducted studies, there exist various reasons such as some studies and general monitoring of dams which cause some main problems including salinity, chemical and microbial pollution eutrophication, and sedimentation. Chame-Gardalan Storage Dam in Ilam Province is one of the storages which have many environmental issues because of discharge upstream rural wastewaters, animal excreta, agricultural drainage, and leachate. The aim of this study is to signify the quality of Ilam’s storage Dam and also to recognize the pollutant resources
and to analyze the pollutants’ behavior at different times and sites in order to determine dam propertiesfor agricultural and domestic usages. Regarding the importance of the topic, the present study (inthe year 2012) is based on the collected information of water quality of the basin, recognition of pollutant resources
and measurement of qualitative parameters such as Temperature, TDS, EC, BOD5, COD, nitrogen, phosphor, and pH in seven periods of time (from May to November). The results show that the total increase in the concentration of all variables along the basin are over double, in particular, Nitrat, Sulfat, BOD, and COD. After analyzing data with some water quality indexes, we analyzed water quality of the storage and some strategies were applied in order to control of effect decrease in the dam storage which, a management program was presented to improve water quality.