In this present study seasonal water quality of River Henwal was conducted in term of the physico-chemical parameters, heavy metals, and plankton composition at four different sites of Chamba, Distt, Tehri Garhwal to observe pollution grade of River Henwal, situated in newly carved state of Uttarakhand. One site was considered as control site out of four and low concentration of physicochemical parameters was observed at it. For this purpose, comprehensive pollution index (CPI) was used, in view of the physiochemical parameters such as conductivity, turbidity, dissolved oxygen, total solids, total hardness (TH), total phosphate, chloride etc. and heavy metals (Fe, Cu, Zn, Cr etc.). Besides this, Simpson index (D) and Shannon-Weaver index (H) and Taxon Evenness (E) are used to depict the planktonic density, diversity and evenness in Henwal river. The CPI value (4.70-10.31) classifies the water quality in severely polluted condition of river water. Highest value was at Khadi. Blue green algae and protozoa were the most abundant group was recorded at all four sites. The highest Simpson (4.74), Shannon-Weiner index (1.58) and taxon evenness (0.46) was at Nagni during monsoon and lowest was at control site (D = 4.37, H = 1.54 and E = 0.43) during winter. Negative correlation was found between turbidity and plankton.