In this paper, an optimisation procedure is developed for calibration of the both types of hydraulic simulation models, demand driven and pressure dependent analyses, by using genetic algorithm. Variables of pipe roughness coefficient, nodal demand and pipe diameter are investigated for calibration of the hydraulic models. Four scenarios of minimum, normal, maximum and fire consumption are considered for calibration. In addition, the leakage term is incorporated into the hydraulic equations to be able to evaluate the hydraulic situation more realistically in both demand driven analysis (DDA) and pressure dependent analysis (PDA) based models. The suggested calibration procedure is applied on a test network with different consumption scenarios and variables. It is found that the best results are obtained with fire consumption case and both variables of pipe roughness and nodal demand. Leakage consideration reduces the weaknesses of the low flow scenario and also PDA produces lower error values in comparison with DDA.