Evaluating the Resilience of Drinking Water Systems to Severe Weather Events Using Boil Water Notices and Bottled Water Sales.

Increasing weather-driven disruptions to water supplies have raised growing concerns about the resilience of drinking water infrastructure and equitable access to safe drinking water during severe weather events. This study seeks to address gaps in evaluating and understanding the resilience of community water systems (CWSs) to severe weather events at regional scales, including both the physical infrastructure and population served. We developed an approach that combines boil water notice (BWN) occurrence and duration as a metric of CWS performance and bottled water sales to capture community response to water disruptions. We conducted multiple fixed-effects panel regressions to quantify relationships of these metrics to severe weather events and operational and sociodemographic characteristics using a statewide analysis of Texas, United States from 2010 to 2022. We found that small, publicly owned, and groundwater-sourced CWSs are most susceptible to BWNs. Winter weather and hurricanes significantly increased BWN duration by 1.6 and 1.1 days, respectively. During weather-driven BWNs, high-income counties had a significant increase in bottled water purchasing (+30.9%) while low-income counties did not exhibit a significant increase. This study provides a better understanding of differences in vulnerability of CWSs to weather events and the associated response of populations served at regional scales.