Drinking water should be disinfected through chlorination which is the most crucial stage (final stage) of treatment applied in a clear well. This study was undertaken to examine the water quality typically residual chlorine in the distribution network of Kombolcha Town. The data was collected from three sampling locations, the sample from the oldest pipe aged within consecutive three days for four reservoirs and four taps. The sample was taken in February 2022, just taken sample water from the tap onsite to measure pH, temperature, and chlorine residual. The Ph and Temperature were recorded after calibrating an instrument ph meter. Crushed DPD-1 Tablet into a little amount of sample water then put it for 10 minutes until color change comes finally, measured Residual chlorine from (diethyl paraphenylenediamine) DPD-1 indicator test, respectively. As indicated in the laboratory result Colony counter, a lot of Feacal coliform bacteria were founded, up to 208 feacal coliforms/100ml water. The Hydraulic model calibration of the difference in correlation value of simulated and observed model data has become a good value with the root mean square of R=0.9816. After model calibration, Reservoir residual chlorine amount was set at 0.5mg/l for EPANET and its result in the distribution was between 0.2 to 0.5 mg/l. But the field actual residual chlorine was recorded as 0mg/l. Finally, the comparison of the EPANET model and field-recorded values of residual chlorine was made to observe the differences. As a recommendation, any water-related office shall use quality assurance software like EPANET in addition to water cad design. Finally, as the distribution network was infected with feacal coliforms, the town water supply office must be added the proper amount of chlorine within a regular period in the reservoir. Keywords: - Chlorine residual, Chlorination, Coliform, EPANET