Water plays a key role in the economic growth of an agricultural country. Pakistan is a farming country that uses almost 90% of its water resources for agricultural purposes. Khyber Pakhtunkhwa (KPK) province of Pakistan is blessed with extensive surface water resources. In addition to using groundwater resources for irrigation, large parts of its flat plains are irrigated with the Kabul River surface water. Due to large population growth and unregulated small/local scale industries in the region, surface water quality deteriorated with time. Which impacts people's health when polluted surface water is used for irrigation purposes. This research investigates the surface water quality of Kabul River's different tributaries and identifies the most critical locations in terms of water quality. Various physical, chemical, and biological parameters at ten sites on as many Kabul River tributaries are examined to investigate surface water quality. The distance and weightage-based identification method is used to identify the most critical and vulnerable locations for each parameter. The maximum seven critical values determined against the Bara River using the weightage-based method, i.e., 17.5, 5.95, 7.35, 27.65, 1.75, 0.35, and 10.45 for total alkalinity, sodium, total hardness, magnesium, total suspended solids, BOD, and turbidity. In comparison, the distance-based iteration method is used to identify the most vulnerable location against the specific parameter. All the results are finally compared with the interpolated values over the entire region using Kriging interpolation. The areas are mostly the same identified through the distance and weightage-based method. The results will guide the competent authority to install the monitoring station and treatment plants for specific parameters responsible for the critical location and to stop further contamination of the particular parameter near the threshold.