In Bangladesh, where hundreds of rivers course across a vast deltaic landscape, water simultaneously supports and threatens complex ecosystems and diverse livelihoods. For instance, a flood can quench thirsty rice paddies or destroy infrastructure; brackish water sustains mangrove forests and shrimp cultivation but also contaminates drinking water and renders land sterile. Whether a hydrological condition is interpreted as beneficial or hazardous has profound implications for water management. Combining archival records, in-person interviews, and policy reports, this work examines how the translation of foreign expertise into local water management interventions has exacerbated rather than mitigated the risks of floods, droughts, seawater intrusion, and cyclones in Bangladesh. Not only were foreign engineering schemes from the North Atlantic inappropriately prescribed for the Bay of Bengal, but local understandings of floods as both benign and perilous were collapsed into a singular definition that led to policies aimed at eliminating rather than managing such events.