This research examines how traditional regulatory and voluntary approaches affect motivations to address potential harms to water quality. The traditional approach consists of governmental enforcement of mandatory requirements; the voluntary approach consists of government calling attention to potential harms and facilitating actions to address them. These approaches are best thought of as ends of a continuum rather than as the sole choices. Three sets of findings emerge from the research. One, not surprisingly, is that traditional regulation is more effective than the voluntary approach alone. A second shows that deterrent fears and the sense of duty to comply are important motivations for action. A third concerns factors that account for the variation in each motivation for which inspections, peer reputation, and attitudes toward government are shown to be important considerations. These findings point to the duality of deterrent fears and civic obligations as motivations to address potential harms.