Ecosystem services engages support among people, especially policy-and decision-makers, for the recognition that human welfare, prosperity, security, and well-being are intrinsically linked to the health of the environment. As our Earth's population increases and a changing environment creates change in our natural and social habitats, we see changes in attributes of our most critical resource, such as availability and quality of water supplies. We propose exploring institutional policy, infrastructure, human behavior, and social processes relative to water supply, allocation, and delivery for human use. This theme and our interdisciplinary approach offer unprecedented opportunity to elicit new information that could have important bearing on environmental security.