Most Dhaka City dwellers in Bangladesh depend on potable water supply from Production Tube wells (PTWs) under the Dhaka Water Supply and Sewerage Authority (DWASA). Water is a means of transmitting disease and causes illness by being contaminated with pathogenic microorganisms and dissolved pollutants. Chlorination is usually done in large networks to ensure acceptable water quality. Although a chlorination system is adopted in a particular District Metered Area (DMA) of Dhaka city, it is controlled by a limited number of potential chlorine injection points, typically the PTWs of such DMAs. The present study assesses the effectiveness of the chlorination system adopted in a particular DMA of Dhaka city. For that, residual chlorine was measured and predicted at selected locations within the network over space and time under various operating conditions using EPANET. The residual chlorine model was calibrated and validated using time-varying residual chlorine concentration data collected at several control points within the DMA. The measured bulk residual chlorine decay rate (kb) was −0.2975 h−1. The calibrated wall residual chlorine decay rate constant (kw) was −0.0065 ft/s. Model simulation of the baseline scenario indicated that more than 50% of pipes do not get any chlorine under the present chlorination scheme. The additional six injection points increased the chlorine coverage over 86% of the pipes. EPANET is a tool that may be used to control the concentration of residual chlorine and assess the effectiveness of the existing chlorination system in different DMAs under DWASA. Chlorine by-products are categorized as emerging pollutants, with their presence in water resources linked to endocrine disruption and other adverse biological effects.