Abstract
Describes the theory and use of a numerical model for the simulation of unsteady flows along closed and open conduits in an urban drainage system. The model discussed is based on the conceptualisation of the drainage system into a network of nodes and links and the use of this conceptualisation to develop an efficient solution algorithm for the unsteady flow simulation. Inherent in this approach is the use of network units; each unit comprising a single link with nodes at the upstream and downstream ends of the link. Data requirements and the format of the datafiles required for operation of the model are presented in this report.