The goodness-of-fit of model calibration is evaluated by the discrepancy between the model simulated and field measured junction HGL and pipe flow. The goodness-of-fit score is calculated by using a user-specified fitness-point-per-hydraulic head for junctions and fitness-point-per-flow for pipes. This allows a modeler to flexibly weight the evaluation of both pipe flow and junction hydraulic head. Three fitness functions are defined as follows: