AWWA JAW50197

Water distribution models are used to simulate a variety of conditions, including extreme flow events such as maximum hour demands and fire flows. Some models are tested only under average demand conditions, in which head loss is commonly of the same order of magnitude as errors in head loss measurements. Data collected when head loss is small in comparison with errors may give the false impression that the model is properly calibrated. Substantial errors may exist in the model that will not become apparent until the model is used at a time when head loss and velocity are high. This article contains guidelines for collecting data so that the model calibration will be meaningful. Includes 23 references, figures.