We explore the relationship between water security (WS) and adaptive capacity (AC); the two concepts are connected because achieving the first may be dependent on building the second. We focus on how metrics of WS and AC are operationalized and what implications they may have for short- and long-term management. We argue that rather than static conceptualizations of WS and AC, we need to understand what combinations of capacities are needed as a function of how controllable key parameters of WS are and the types of outcomes we seek to achieve. We offer a conceptual model of the relationship between WS and AC to clarify what aspects of human-water interactions each concept emphasizes and suggest a hypothetical example of how decision-makers may use these ideas.