More active leakage management is required to take discharge ratio into consideration, regarding its significance in water distribution system operation and management. This study suggests the new leakage detection model, which makes use of the uncertainties in roughness coefficient and optimization methods. This study employs the Semi-Pressure Driven Analysis (Semi-PDA), which enables realistic leakage modelling without the Head Outflow Relationship, (HOR), of which uncertainties are large in conventional hydraulic analysis of the water distribution system. The Beta decrease function and the Latin Hyper Sampling (LHS) are also used to analyse the uncertainties in roughness coefficient. This study develops the Semi-PDA model, employing the Emitter function of the EPANET2, water distribution system analysis program, and locates the leakage by optimizing the Emitter coefficient. The suggested model is proved to be efficient in detecting the location of the leakage, according to the analysis of example network.