Estimation of Water Quality Parameters of Rawal Lake and Its Associated Tributaries

Globally, the rapid growth of the population over the past century has put enormous pressure on freshwater resources. Pakistan, as a developing country, also faces a freshwater crisis. Rawal Lake, an essential freshwater reservoir near Pakistan's capital, has been showing signs of deterioration for the past few years. Therefore, a brief study was planned to analyze the water quality of the lake and the associated recharge streams. Twelve physical and chemical parameters were selected along with the total bacterial and Escherichia coli count. Five sampling points were selected for water sampling. Results showed that the Mallpur stream significantly has higher pH, total suspended solids, and total dissolved solids values than the other sampling points and was not within the permissible limits of the World Health Organization. In the case of total bacterial count and Escherichia coli count, except Spillway, water samples showed higher concentrations than the permissible limits of world health organization. However, the mineral content such as Calcium, Magnesium, Nitrogen, Potassium, Chloride, and sulphate concentration at all sampling points are within the permissible limits of the world health organization's drinking water standard. Results also showed that the water sampled from the Korang River tributary has more deterioration in physicochemical properties as well as in total bacterial count than the Mallpur tributary. Due to the deterioration of the water quality parameter, it is suggested that Rawal Lake water is not suitable for human consumption.