Student Energy Research Spotlight: An Operational Model of Interdependent Water and Power Distribution Systems

By LCDR Brendan Bunn

As military and public needs become more complex and interconnected, so too does our infrastructure. Both military and civilian communities require critical services for daily life, including water, food, shelter, energy, mobility, and communications among others. The infrastructure systems providing these services are sometimes interdependent, such that the systems themselves require critical services to operate. This is especially common for water and power systems found on military installations and remote island territories where local electricity needs water to run generators and water needs electricity to run pumps. These interdependencies often improve the efficiency of both systems by sharing scarce resources and making operations easier. However, during natural disasters and extreme events interdependencies also lead to service failures that impact both systems simultaneously and are difficult to manage. To plan for extreme events, we need detailed engineering models that include water-power interdependencies. Unfortunately, these models do not yet exist. 

We filled this gap by developing an interdependent model of potable water distribution and electric power distribution operation at the island and installation scale. We aimed to capture key attributes and essential interdependencies of these systems with enough fidelity to represent real infrastructure physics, measure how networks perform in various crisis scenarios, and present new insights on interdependencies. Our final model links established engineering models for water and power networks which we used to study interdependent water-power system behavior across a series of emergency scenarios.

Results reveal important insights for interdependent infrastructure modeling and analysis. Most notably, we found different classes of interdependencies can lead to similar failure outcomes, and that these failed states happen even when dependencies between systems are not bi-directional (i.e., water depends on power, but not vice versa). This result has implications for infrastructure management on military installations and remote island territories and may impact design choices moving forward. Overall, the final model provides both realism and simplicity, making it an ideal foundation for future analysis for more complex water-power systems in military and civilian contexts. 

ABOUT THE AUTHOR
LCDR Brendan Bunn is a recent graduate of the Naval Postgraduate School's Operations Research program and is a Navy Civil Engineer Corps Officer. He is currently working for OPNAV N81 as a force generation shore readiness analyst.

Contact the EAG team for more information about this research.