Optimal Management of Water Distribution Networks with Simulated Annealing: The C-Town Problem

Abstract

Sustainability is a major issue for water companies, who have to provide high quality services at achievable costs. In this context, water loss control and energy efficiency are two great challenges water companies have to face. Water loss represents both higher service cost (real losses) and loss of revenue (apparent losses), while the energy bill from treatment plants and pumping stations represents a significant part of the service cost. The Battle of Background Leakage Assessment for Water Networks (BBLAWN) was a competition dedicated to this subject: water distribution network (WDN) optimal management. Teams/individuals from academia, consulting firms, and utilities were invited to propose methodologies for solving the C-Town WDN problem: minimize operational and capital costs and background leakages. This paper presents one of the methodologies proposed at BBLAWN. The methodology proposed here to solve the C-Town WDN problem comprises two optimization models: a least-cost design model to identify the pipes to be replaced and size them, and an optimal operation model to define the pump controls and the PRV settings. Both models are solved by linking a hydraulic simulation model with a simulated annealing algorithm. This approach, supported by some additional engineering expertise, provided a set of good solutions in terms of operational and capital cost, and a good compromise with the environmental and financial damage caused by water losses.