Toward Greater Resilient Water Infrastructure to Future Hydrometeorological Extremes: Lessons from Oroville Dam and Hurricane Harvey

Aging infrastructure, increasing population and human development are exacerbating the impacts of record-breaking storms, which are projected to increase in frequency with climate change. This convergence of risks provides new challenges for the water management community and leads to events that fall outside the design paradigm traditionally considered in planning for meteorological and hydrological extremes. Our goal in this study is to begin a discussion across disciplines on how to build capacity to deal with extremes and risk where existing planning methods are insufficient for shifting hydrometeorological regimes. This paper identifies three questions to be addressed when conceptualizing this new capacity: (1) What determines which hydrometeorological event(s) will result in major impacts for water management? (2) How can we assess risk and identify relevant tipping points that transform the built environment? And (3) What new metrics and standards are needed to create resilient infrastructure for the most impactful extremes in a nonstationary world? Two case studies in different regions serve as informative examples for approaching these questions. In August 2017, Hurricane Harvey combined a record-breaking storm that exceeded probable maximum precipitation thresholds with land use challenges to yield monumental water-management impacts in and around Houston, TX. In February 2017, a series of atmospheric rivers combined with infrastructure challenges resulted in a major dam-safety crisis in northern California. These two cases provide evidence that our traditional purely meteorological definitions of extreme events used in planning and operations need to be reevaluated. Specifically, it is necessary to combine meteorological with socioecological factors that can result in water-management disasters. This reframing will be essential for establishing better engineering and management practices to support resilient infrastructure based on standards that include the potential occurrence of extreme weather events well beyond the historical record.