Redundancy model for water distribution systems

This paper presents a model, based on head driven simulation, for assessing the redundancy of water distribution systems (WDS). The formulation recognises the pressure dependency of water consumption in the solution procedure. A new algorithm for pressure dependent modelling of WDS has, therefore, been developed. Notable features of the proposed network analysis technique include the introduction of a new subcategory of nodes called key partial-flow nodes and the use of a joint head-flow system of equations. The algorithm is reliable, quick and easy-to-implement. The redundancy assessment methodology addresses the randomness of component failure or unavailability. Results are presented which demonstrate the suitability and meaning of the redundancy measure. In particular, it is recommended that redundancy be evaluated along with reliability when assessing system performance. The computer program developed can seamlessly calculate several performance indicators including reliability.