Model for water distribution system reliability

The hydraulic reliability of a water distribution system can be defined as the probability that the system can provide the demanded flowrate at the required pressure head. Due to the random nature of future water demands, required pressure heads, and pipe roughness, the estimation of water distribution system reliability for the future is subject to uncertainty. A methodology is presented to estimate the nodal and system hydraulic reliabilities of water distribution systems that accounts for the uncertainties. The framework for the methodology is based upon a Monte Carlo simulation consisting of three major components: random number generation, hydraulic network simulation, and computation of reliability. For purposes of illustration, an example water distribution system consisting of 17 pipes and 12 demand nodes is used. This new methodology can be used in the analysis or expansion of existing systems, or the design of new systems.