Hybrid wastewater treatment and reuse enhances urban water system resilience to disruptive incidents

Water and wastewater systems are critical infrastructure whose disruption directly threatens public health, economic growth and the reliability and functionality of other critical infrastructure. Hybrid urban water supply systems that combine conventional, centralized water sources with distributed reclaimed wastewater offer potential energy savings and reduced freshwater use. Here we show that such hybrid water supply systems are also more resilient than conventional centralized systems. Using Houston’s municipal water system as a case study, we explore the resilience of hybrid systems compared with centralized ones under various disruptions including pump station failures, pipe leakage and source water contamination. Our quantitative analysis reveals that the hybrid configuration demonstrates lower severity, impact range and downtime during substandard performance, especially benefiting low-pressure areas vulnerable to disruptions. We also identified vulnerable components in the current system along with appropriate mitigation strategies that account for local geographical constraints. These findings emphasize the imperative of considering alternative system configurations to safeguard water infrastructure and mitigate risks efficiently.