Disruptions of imported water conveyance and basin-wide distribution were determined to be major impacts. A follow-up analysis of water system impacts (Davis and O’Rourke, 2011) estimated that it would take at least 12-15 months for water service to be completely restored for much of the affected population, and that the costs of business interruption losses due to water supply reduction would likely be much greater than USD 50 billion. The study concluded that there is a need to increase local water storage.