Controlling the residual chlorine concentrations is crucial in the management of water quality in drinking water systems to avoid overdosing or insufficient doses issues. The research employs EPANET to simulate chlorine dissipation in a part of the Sultanate of Oman's drinking water distribution network. To estimate chlorine bulk and wall decay rates through the real network, a combination of bottle tests and a pilot-scale pipe system were involved in this research. EPANET simulations conducted under two scenarios reveal that the first scenario aligns most closely with actual network conditions. The results shed light on the critical consideration of wall decay, particularly in aging pipe sections, suggesting that neglecting this factor may lead to inaccurate predictions. Model validity is shown to be influenced by initial chlorine concentrations, underscoring the significance of obtaining precise data about the network starting from the main reservoirs’ outlet to the last pipes section. This study suggested further investigations into the latest part of the selected distribution network that showed a necessity to enhance free residual chlorine. Potential strategies should be developed for effective monitoring and management of residual chlorine concentrations, taking into consideration the factors that may affect its dissipation.