A model (NETWORK) is presented for the simulation of unsteady flow in regulated open channel networks. The operation of hydraulic structures, such as gates and weirs, are simulated as well as leakage through the perimeter of the channels. The model is useful for analysis of flood control measures, simulation of various gate operating rules, and comparing water delivery schemes over large distances where there is significant loss to leakage. Verification was accomplished by comparing a simulation run on the Potomac River by NETWORK to the same simulation using the BRANCH model by R.W. Schaffranek. The results show excellent agreement for the conditions simulated.