Complex, multihazard risks such as private groundwater contamination necessitate multiannual risk reduction actions including seasonal, weather‐based hazard evaluations. In the Republic of Ireland (ROI), high rural reliance on unregulated private wells renders behavior promotion a vital instrument toward safeguarding household health from waterborne infection. However, to date, pathways between behavioral predictors remain unknown while latent constructs such as extreme weather event (EWE) risk perception and self‐efficacy (perceived behavioral competency) have yet to be sufficiently explored. Accordingly, a nationwide survey of 560 Irish private well owners was conducted, with structural equation modeling (SEM) employed to identify underlying relationships determining key supply management behaviors. The pathway analysis (SEM) approach was used to model three binary outcomes: information seeking, post‐EWE action, and well testing behavior. Upon development of optimal models, perceived self‐efficacy emerged as a significant direct and/or indirect driver of all three behavior types—demonstrating the greatest indirect effect (
β= −0.057) on adoption of post‐EWE actions and greatest direct ( β= 0.222) and total effect ( β= 0.245) on supply testing. Perceived self‐efficacy inversely influenced EWE risk perception in all three models but positively influenced supply awareness (where present). Notably, the presence of a vulnerable (infant and/or elderly) household member negatively influenced adoption of post‐EWE actions ( β= −0.131, p= 0.016). Results suggest that residential and age‐related factors constitute key demographic variables influencing risk mitigation and are strongly mediated by cognitive variables—particularly self‐efficacy. Study findings may help contextualize predictors of private water supply management, providing a basis for future risk‐based water interventions.