The large-scale introduction of water reuse into an existing water supply system is a complex socio-technical process. Consumers drive the success of water reuse programs through adoption, and infrastructure designs affect adoption patterns. This research develops a modeling framework to capture the feedbacks among consumer adoption and infrastructure expansion. Two theories are applied and compared to simulate the diffusion of water innovations. Theories are modeled as a neighborhood-based diffusion and a network-based diffusion. Models are applied to simulate and project adoption of water reuse for the Town of Cary, North Carolina.