This research report defines the Underground Taming of Floods for Irrigation (UTFI) concept, an approach for co-managing floods and droughts at the river basin scale with a potential to address climate change adaptation and mitigation and disaster risk reduction challenges globally. UTFI involves strategic recharge of aquifers upstream during periods of high flow, thereby preventing local and downstream flooding, and simultaneously providing additional groundwater for irrigation during the dry season for livelihood improvement. Three key stages in moving UTFI from the concept stage to mainstream implementation are discussed.