Abstract: Surface water quality assessment is a basic and critical tool for informing sustainabl management of water resources. The aim of this study is to evaluate the dam and reservoir water quality of the Bhavnagar region.. The results will assist water management in the study area for varied future demands including, irrigation, industries, and river conservation. Ecologically important parameters such as dissolved oxygen, chemical oxygen demand, biochemical oxygen demand, physico-chemical parameters (PH, Conductivity, Turbidity, sodium, potassium, lithium, calcium, hardness, solids, chloride, fluoride, sulphate, nitrate, phosphate, metals, Alkalinity) were analyzed. The results were compared with standard permissible limits of BIS and WHO. The differences in various parameters were statistically significant when comparing the pre-monsoon and post-monsoon of dam and reservoir. To identify a good technique for water quality assessment, all of the water quality parameters have been calculated by correlating various parameters and comparing them over two critical seasons with BIS. The Thematic map Map of The Water-quality parameters indicate that Dam/Reservoir Water is safe for Drinking and irrigation Purpose.

Keywords: Dam and reservoir, physico-chemical parameters, correlation parameters, water quality, Bhavnagar region, Thematic Map.

| DOI: 10.17148/IARJSET.2021.8553