Resilience-based infrastructure planning and asset management: Study of dual and singular water distribution infrastructure performance using a simulation approach

Dual water distribution systems have been proposed as a technological infrastructure solution to enhance the sustainability and resilience of urban water systems by improving performance and decreasing energy consumption. The dual system separately distributes non-potable water for outdoor demand and potable water for indoor demand. The objective of this study was to evaluate the long-term performance of dual water distribution systems versus singular systems under various scenarios of renewal strategies and demand fluctuations. To this end, a dynamic (time-dependent) simulation model was developed to capture long-term dynamics of water distribution infrastructure systems using empirical relationships. The model integrates utility agency's renewal decision-making processes with the physical infrastructure degradation to simulate the long-term transformation of the pipeline network. Various system performance measures, including breakage, leakage, energy loss, level of service, and life-cycle costs, were simulated over a 50-year horizon. The simulation model was implemented using data from the City of Fort Collins, CO, and used to examine the long-term performance of the dual and singular water distribution systems. The analysis results enabled: (i) understanding the long-term transformation of water distribution systems; (ii) comparing different performance measures of dual and singular systems; and (iii) exploring the sensitivity of both systems to demand fluctuations.