Ecological Decentralization for Improving the Resilient Design of Urban Water Distribution Networks

Urban water distribution networks have provided potable water to communities and households worldwide over the last century. Within the last two decades, there has been a rise in complications with water distribution systems meeting demands. Urban water distributions fail to meet demands due to increases in natural and man-made disturbances, population growth, and aging water distribution network structures. These issues have caused urban water distribution system designers and decision-makers to shift their interests from focusing solely on efficiency to designs capable of meeting customer potable water demands under normal operations and during disturbances. Ecology, specifically biological ecosystems, provides system resilience inspiration, taken from their structure and functioning that has survived disturbances over millions of years. The work here investigates mimicking the decentralization of food webs to improve network resilience by incorporating decentralized water storage tanks, using the established two loop network (TLN) as a case study. TLN is an introductory water network provided by the University of Exeter for system engineers and designers to test optimization and exploratory techniques. The case study was selected due to its simplistic design which allowed the authors to understand the effects of decentralizing the network toward improving its ability to handle disruptions. The findings suggest decentralization can improve the water network resilience a minimum of three times as much as the original network's design. Furthermore, introducing decentralization was also found to increase the system's ability to meet the demand for all nodes during disruptions, something the original case was unable to accomplish while simultaneously reducing the amount of freshwater consumed during disruptions.