In the Netherlands, dykes and other primary water defence works are assets that are essential to keep the society and economy functioning, by protecting against flooding from sea and rivers due to extreme events. Given that 55% of the country is at risk of flooding, primary water defence works belong to its critical infrastructure. Many factors influence the risk and impact of flooding. Besides physical factors (e.g., landscape design, climate change) also socio-economic factors (e.g., population, assets) are important. Given that these factors change and feature complex and uncertain behaviour in past and future, the design and regulation of this critical infrastructure will have to be flexible enough to be able to deal with such changes. ‘Planned Adaptation’ refers to regulatory programmes that plan for future changes in knowledge by producing new knowledge and revising rules at regular intervals. This study describes the emergence of the next generation of Dutch primary water defence infrastructure, which through the stepwise implementation of Planned Adaptation for design and testing of primary water defence works in the mid-1990s has moved beyond the Delta Works approach of 1953 and subsequent unplanned adaptations. This has prepared the ground for the recent introduction of Adaptive Delta Management, which makes an integral part of the new Delta Plan for the Netherlands that was published on 16 September 2014 and which is also analysed in this study.