Thesis (M.S., Water Resources) -- University of Idaho, 2016 | The Columbia River Basin, which spans seven U.S. states and two countries, is located in a diverse socio-ecological region of the Pacific Northwest with stakeholders ranging from flood risk managers, irrigators, power utilities, ecological interests, and more. With the governing document of the bi-national management of the Basin, the Columbia River Treaty, under current review, significant flood risk management policy decisions are looming. This research examines historic flow events that exceed the amount deemed to cause flood damages and determines that actual damages at the prescribed threshold flood discharge are minimal in recent events. Additionally, an exploration of the costs and benefits of non-structural flood control measures and an allowance of increased flows shows qualitative and quantitative ecological, social, and economic benefits. This work intends to show the importance and need for further research and examination of flood risk management policy in the Columbia River Basin by applicable stakeholders.