An approach is proposed for calibrating hydraulic network models.The proposed procedure could reconcile results of all scenarios under various operation conditions and utilize prior information selectively.To achieve more accurate roughness with a faster processing,a hybridoptimization technique was developed to exploit advantages of genetic algorithm and active set method.The algorithm was applied to two sample networks,and resulting calibrated model was compared to counterpart in previous literature.The proposed approach was shown stable and estimated parameters were more accurate.