Water supply delivery failures-a scenario-based approach to assess economic losses and risk reduction options

Access to a reliable water supply is central for a well-functioning society. However, water supply systems are subject to a wide range of threats which may affect their ability to provide water to society. This paper presents a novel risk assessment approach that enables thorough analyses of economic losses and associated uncertainties under a range of water supply disruption scenarios. The purpose is to avoid sub-optimization when prioritizing between risk reduction measures, by integrating the full range of possible outcomes from low to high probability events. By combining risk analysis with cost-benefit analysis, additional information is provided on measures for leveraging investments in managing and reducing the risks. This enables the identification of the most economically profitable risk reduction alternatives and enables decision makers to build strategic capacity for operating in difficult and uncertain futures. The presented approach is exemplified on the island of Gotland, one of the most water scarce areas of Sweden. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.Funding details: Svenska ForskningsrÃ¥det Formas, 942-2015-130; Funding text 1: This research was funded by the European Union's Horizon 2020 research and innovation program under the Marie Sk?odowska-Curie grant agreement No 754412; Region V?stra G?taland; and the Swedish Research Council Formas contract no 942-2015-130. This research was performed within the DRICKS center for drinking water research coordinated by the Chalmers University of Technology. The authors would like to thank Mikael Tiouls and Lars Westerlund, as well as all other workshop participants, at Region Gotland for contributing with Gotland-specific expertise on scenarios and societal effects.