A study was carried out to analyze the physicochemical parameters of sacred lake during November 2015–October 2016. Keeping in view the purpose of the study different analysis has been done to check the water quality of the Prashar Lake. Water quality was evaluated seasonally by using water quality index (WQI), which reflect the defined and future use of water. Different statistical methods: Pearson’s correlation, cluster analysis and principal component analysis, were executed for the water quality parameters. WQI ranged between 23 and 50 in different seasons (winter > spring > autumn > summer > monsoon). Cluster analysis of similarity indicated the relationship intensity between the seasons as cluster ranging 77–100% during the study period. PCA identified that water temperature, conductivity, turbidity, BOD, TDS, hardness, calcium, phosphate, sodium and potassium were main parameters which reduced the quality of water during the summer and monsoon seasons. The outcome revealed that the main factors which degrade the water quality in monsoon season were mainly entering of tourist-generated waste and surrounding erosion due to overgrazing on the Prashar Lake area.