Customer trust in a community's water utility infrastructure is essential for making collaborative decisions via adaptive management strategies. Such strategies become increasingly important when an area served by a utility undergoes economic and socio-demographic transformations including population decline. Water infrastructure system trust has been researched in prior one-dimensional studies, such as trust in water quality or trust in water utility management. A more complete picture can be obtained from the range of multidimensional interactions between water infrastructure and end-users. Here, we develop a multidimensional construct of trust in water infrastructure systems of US shrinking cities by using confirmatory factor analysis (CFA) and structural equation modeling (SEM). We confirm the validity of the proposed construct by examining how such trust is impacted by predictors from the literature (i.e., trust in government, financial ability to pay water bills, experience with water-related events, and water consumption patterns). When water purveyors and infrastructure managers have a better understanding of end-user trust, it will help them strengthen their long-term trust relationships. By strengthening them, purveyors and managers will be better positioned to make collaborative decisions to maintain the system's desired state and adapt to disturbances while maintaining the system's functionality.