Although the flood hit the entire part of Chennai, Tamil Nadu some 3 years ago, the quality of water is still found to be worse because of major inundation in these areas. The current inspection deals with the physico-chemical analysis of the groundwater samples collected from 10 locations in Neelangarai and Triplicane areas in Chennai, Tamil Nadu, and assessed using the Heber Water Quality Index (HWQI) in the post-tsunami circumstances. The factors examined were pH, fecal coliform, total dissolved solids (TDS), dissolved oxygen (DO), temperature biochemical oxygen demand (BOD), and turbidity. In addition to these parameters, pointers like electrical conductivity and salinity were also taken into consideration. The overall HWQI outcomes for all the trials in the Neelangarai area were between 65.02 and 72.25 and the Triplicane area was 66.64–70.71, which suggests that all the samples are medium to good in quality and could used for human consumption.