This paper examines compacts used by U.S. western states to engage in shared governance of interstate rivers. Compacts are viewed as inflexible, rigid governance structures incapable of responding to changing environmental and institutional settings because of the use of unanimity rules and the inability to directly regulate water users. Using data from a study of 14 western interstate river compacts we examine this claim. In particular, we explore the response of compacts to water conflicts. We find that members of compacts, closely related water agencies, and compact governments are capable of responding to conflicts. To better understand this finding, we identify the conditions under which compacts are likely to address conflicts, as well as the types of conflict solutions compact governments adopted.