Flood-risk management (FRM) is shaped by context: a society's cultural background; physical possibilities and constraints; and the historical development of that society's economy, politi- cal system, education, etc. These provide different drivers for change, in interaction with more global developments. We compare historical and current FRM in six delta areas and their con- texts: Rhine/Meuse/Scheldt (The Netherlands), Pearl River (China), Mekong (Vietnam), Ganges/ Brahmaputra/Meghna (Bangladesh) Zambezi/Limpopo (Mozambique), and Mississippi (USA). We show that in many countries the emphasis is shifting from -hard' engineering, such as dikes, towards non-structural -soft' measures, such as planning restrictions or early warning systems, while the -hard' responses are softened in some by a -building with nature' approach. However, this is by no means a universal development. One consistent feature of the application of -hard' FRM technology to deltas is that it pushes them towards a technological -lock-in' in which fewer and fewer -soft' FRM alternatives are feasible due to increased ood risks. By contrast, -soft' FRM is typically exible, allowing a range of future options, including future hard elements if needed and appropriate. These experiences should lead to serious re ection on whether -hard' FRM should be recommended when -soft' FRM options are still open.