Abstract: The current study shows the estimation of drinking water supply, future trends and related issues in Varanasi City, India. Varanasi (from 25013’N to 25024’N latitudes and from 820 54’E to 830 04’E longitude) is one of the most important and historic city located almost in the Middle Ganga valley in the northern plain of India. For the convenience of civic administration, the city is presently divided into 90 wards and for the purpose of extending adequate and safe water supply facilities to the entire area, the city has been divided presently into 16 water supply zones of which 5 zones lie in the trans-Varuna area and the remaining 11 zones in the cis-Varuna area. The present work is based on the secondary sources of data which are obtained from Water Supply Department (Jal Sansthan), Nagar Nigam (Municipal Corporation) of Varanasi. In the first phase of the study, data pertaining to ward wise generation of water supply is collected from Water Supply Department, NNV (Nagar Nigam Varanasi). Informal focused group discussion, PRA (Participatory Action Research), and observation technique were applied to get the first hand information about the water supply scenario in the city. In the second phase of the study, Arc GIS 10.1 software was used to create maps for estimation of water supply management. The population growth in Varanasi from 2011 to 2041 is estimated to have a growth of 21% in 30 years at a rate of 2.25 % per year. This growth rate is considered in the model from 2011 to 2041 to predict the water demand in the city. The data was collected from various municipalities as per the office records. It is estimated that the amount of drinking water requirement forecasted for 2021, 2031 and 2041 is 0.49, 0.76 and 1.17 Billion liters per day respectively in Varanasi City. These data show that with an increase in population, the water demand is also increasing decade after decade. Increasing population growth rate, decreasing surface water resources, overexploitation of groundwater, deterioration of ground water quality and poor sewage treatment are the major water supply related issues in Varanasi city, India.