AWWA JAW57536

A host of uncertainties influence the accuracy of network modeling exercises, and some caution is needed to interpret program output and predictions. Too often, the wrong sources are suspected as the causes of model uncertainty. Filion and Karney show that the Hazen-Williams equation was seldom the culprit. The authors hope that their findings will help to stimulate research and an understanding in the industry of the challenges faced by hydraulic and water quality simulations. In addition, they encourage utility managers to use the Hazen-Williams equation with more confidence and to view hydraulic models in general with a little more suspicion. Includes 20 references, figures.