185Review of the Columbia River Treaty between the United States and Canada presents an opportunity to consider how governance might be made more adaptive in the face of climate change while maintaining an appropriate level of stability. Climate change scenarios applied to the Columbia River Basin predict an increasing water deficit due primarily to change in timing of runoff and increased vegetative demand as the result of warming. Current users that will suffer the most from change in timing of runoff are those dependent on late summer flow—fish and farmers. The intersection of climate186 change with normal climate variability also suggests greater extremes that will require planning for both drought and flood beyond the historic recurrence and magnitude. A problem-solving approach to bridge the gap between the status quo and a modernized system must be combined with new approaches to governance that are both more flexible and more responsive to change if the basin is to navigate the future. This challenges not only the conventional wisdom that regulatory stability is essential to economic stability and achievement of societal goals, but also the existing distribution of benefits among powerful players in the basin. Yet the goals of even the current recipients of benefits will not be met if a rigid approach is maintained as climate change unfolds. Adaptive water governance requires attention to institutional structure, introduction of adaptive authority and local participatory capacity including knowledge building, and process design that balances stability with flexibility. Models for implementation of these factors are found in international law and provide a pathway to adaptation to climate change through a modernized transboundary water agreement on the Columbia River.