Preparing for High Consequence, Low Probability Events: Heat Water & Energy in the Southwest

Residents of the Intermountain Southwest are accustomed to hot temperatures. More than 90 percent of households in Arizona use air conditioning, which accounts for a quarter of the energy consumed in homes: more than four times the national average (U.S. Energy Information Administration).

Now imagine a scenario: It’s June, temperatures are normally over 100 degrees F, but a persistent heat wave causes temperatures to soar over 120 degrees F for several days in a row, with nighttime low temperatures at or near 100°F. Everyone is using their A/C, which overloads the system and results in an extended power outage. Now, not only is it scorching, but without power residents have no way to cool off in their homes. What’s more, the lack of power knocks out the wastewater treatment plant, and now residents lack potable water as well.

You may be thinking that this scenario is highly unlikely, and you’re right. But what if? What if over three million people in the Phoenix metro area lost power during a desiccating pre-monsoon heat wave? Or, what if this situation occurred in Las Vegas, where, in addition to a million residents, there are tourists who are unaccustomed to the heat? How do we plan for something like this? How do we manage the cascade of impacts?

These are the types of questions and scenarios discussed at a workshop, entitled “Preparing for High Consequence, Low Probability Events: Heat, Water & Energy in the Southwest,” held in September in the University of Arizona’s new ENR2 building, in Tucson. The heat-related theme was apt, as temperatures outside topped 100°F. The workshop, funded by the U.S. Bureau of Reclamation, brought together over 30 practitioners in water, energy, and emergency management with researchers, in order to improve connections across these sectors, while increasing knowledge about intersecting risks and research and management needs related to the heat-water-energy nexus in the Southwest U.S.

Talks by prestigious scientists and practitioners set the stage for lively discussions and working sessions. Among the talks were two case studies of cascading impact events in the recent past:

• Daryl Slusher (Austin Water Utility, Assistant Director) described how drought in Texas in 2011 and 2012 drastically reduced water levels in many reservoirs, including the sole water supply for the City of Austin, leading to unprecedented water restrictions and power outages in some areas; and
• Ronald Lane, (San Diego County, Deputy Chief Administrative Officer) discussed a 2011 power outage in San Diego that led to a cascade of impacts, including airport and school closures, transportation disruptions—because the power outage rendered gas station fuel pumps inoperable, and a major sewage spill due to the shutdown of a water and sewage pumping.

Participants, some of whom have managed weather-related crises, generated useful insights into planning and managing rare, but impact-filled cascades of events. One key insight was the need for using “possibilistic” as opposed to “probabilistic” thinking to improve communication with local communities; knowing about what is likely to happen (probabilistic) is useful, but in practice it does not lead to the type of preparation needed for rare, but potentially debilitating events. Some key discussions focused on:

1. What does it take for organizations to learn after disasters? Critical lessons learned during crises are often forgotten, unless institutional mechanisms are in place to capture them. It took a second severe drought in less than a decade for Colorado to set up institutions to tackle simultaneous intersecting impacts (e.g., low water supply and multiple fire outbreaks), through routine pre-crisis planning and preparedness for multiple impacts. In contrast, earthquake-prone Los Angeles successfully mobilized public funding to reduce risks from future quakes by learning from an earlier Mexico City earthquake.
2. As long-term temperature and precipitation trends increase the likelihood of acute high-impact events, what changes in planning are required to develop effective interventions? There are clear lines of responsibility for acute events, such as severe storms or floods, but no single lead agency is in charge of the added risk from long-term trends. This is an important direction in which researchers and practitioners can work together to reduce societal risk, even as exposure to risk (e.g., heat waves, lower water supply reliability, etc.) increases.
3. How can we best coordinate multiple levels of disaster planning and response, in anticipation of high-impact, low probability events? While state and national-level coordination is essential, citizen- and neighborhood-level monitoring, knowledge, and social networks play key roles – but too little is known about those networks, their intrinsic preparedness and adaptability. 'Possibilistic' thinking across all of these levels of decision making and coordination is needed to maximize preparedness, reduce risk, and reduce the costs associated with disasters.

Workshop organizers will produce a workshop report by the end of November. In the meantime, a workshop agenda and PDFs of presentations can be found here.