A gradient algorithm based method is presented for analyzing gradually varied unsteady flow in water distribution networks. Using a Newton-Raphson solution technique, the algorithm simultaneously computes piezometric heads at nodes and flow rates in pipes for all points within the network. Comparisons are made with steady-state extended period simulations to show the robust behavior of the model for a complex water distribution network. The benefits of using a gradient algorithm are its flexibility in coding, versatility in operational conditions, and its application to complicated water distribution networks. The computer program implementing the method is general, easy to use, and allows a dynamic analysis of complex looped and open water distribution networks.