An extended period simulation procedure was developed for metropolitan water distribution networks. Efficient sparsity programming techniques were applied to obtain static network balances using a modified Newton-Raphson technique. An integration scheme was developed to link several static solutions each representing an interval of time. A program, called WATSIM, was developed and tested using field data provided by the San Jose Water Works, San Jose, California. Data included network data, switching data, parabolic characteristics of pumps, reservoir curves, and time varying demand patterns. Three cases were simulated: normal operation, emergency operation, and pump outage conditions. (Modified author abstract)