We reviewed 80 studies from behavior sciences, environmental psychology, resource management, and health communication fields to learn why some voluntary message campaigns sustained conservation behaviors. We found past campaigns reduced residential water use by 0.6% to 54% and reductions lasted less than 1 year. The most effective campaigns included a public plea, social comparison information, easy-to-adopt conservation tips, and linked to additional resources. Effective campaigns also targeted different socio-psychological drivers, such as intention, altruism, peer pressure, and perception of ease or difficulty in adopting new conservation behaviors. To help users sustain water-saving behaviors for longer periods of time, we suggest managers (a) learn user’s intentions and informational preferences, (b) launch feedback programs during critical periods such as a drought, (c) state what the water authority is doing to achieve the conservation goal, (d) customize message content based on a user’s attitude and information preferences, (e) target one easy-to-implement conservation action at a time, (f) praise efficient behavior, (g) communicate through a variety of internet, paper, and other mediums, (h) regularly update message contents, (i) encourage users to publicly commit to conservation, (j) publicly recognize water savers, and (k) allow users to share their conservation experiences.