Effective and timely adaptation can lower the cost of climate change impacts. In the absence of accurate and precise climate predictions, a risk-based approach can explicitly accommodate a range of possible futures to inform adaptation decision-making by identifying priorities and options to manage risk and enhance resilience at least cost to society. While climate change adaptation should be considered in the broader context of water security and not in an isolated manner, it is also critical aspect of, even a prerequisite for, achieving resilient water security over the long-term.