Saving For a Dry Day profiles the efforts to develop the Arizona water bank and the “Offstream Storage of Colorado River Water and Interstate Redemption of Storage Credits in the Lower Division States,” the criteria designed to allow for interstate water banking. The article includes historical information as it pertains to the Law of the River and the Central Arizona Project – critical elements to the proposal – as well as the Secretary’s role. It also examines the Upper Basin perspective on the proposal and environmental and Tribal concerns.