Particle Swarm Optimization of Water Distribution Networks with Economic Damages

Practical hydraulic design is focused only on designing a network that will provide pressure at or above a minimum required to fight a fire in the system without any explicit consideration of potential economic damages to buildings and their contents consumed by fire. The inclusion of economic damages in the design optimization of water networks could help utilities allocate capital resources (pipes, pumps, tanks) to protect valuable infrastructure and people in key areas of a network during a fire. This paper presents a new water distribution network optimization framework that includes in its objective function the cost of pipes and the potential economic damages sustained in fires. The new optimization framework incorporates the uncertainty of design fire flows by modeling them as random variables. A new measure of expected conditional damages is developed and used to quantify potential economic damages sustained in a fire, given the uncertainty associated with design flows. The expected conditional damages function is solved with an efficient numerical integration technique. A case study is applied to the new optimization framework with a Particle Swarm Optimization (PSO) program.