Some of the most significant impacts of climate change are likely to be felt in water resources management, but climate change is not the only uncertainty facing water managers and policymakers. The concept of water security has emerged to address social, economic, political, and environmental factors, as well as the physical determinants of water availability. There are significant challenges for communicating about water security under a changing climate. Water security shares many of the characteristics of climate change with regards to communication. It is a complex concept involving interactions between dynamic human and natural systems, requiring public deliberation and engagement to inform political debate and to facilitate behavioral and cultural change. Knowledge and values about water and climate change are communicated through material experiences as well as through language. Communication about water security and climate change takes many forms, which can be characterized as five key modes—policy, communication campaigns, media, cultures, and environments. More effective communication about climate change and water is needed across these different modes to support meaningful participation and deliberation in policy decisions by a wide range of stakeholders. Integrating climate change into communication campaigns about water security provides opportunities to challenge and reframe traditional formulations of the role of water in society and culture and how to manage water in human settlements, the economy, and the environment. The central challenge for communicating the impacts of climate change on water scarcity lies in the complex interactions between society, policy, technology, infrastructure, the economy, and the environment in modern water systems. Different modes of communication are useful to enable public and stakeholder engagement in understanding the issues and making decisions about how to ensure water security in a changing society and environment.