State projects aimed at technological innovation and social renewal were a widespread phenomenon in inter-war Europe. This is exemplified by the practice of internal colonisation – the construction of new settlements within state territories – in the Netherlands. This article examines one such case, the reclamation and colonisation of the Wieringermeer in the 1930s, in detail. In doing so, it reveals that the principle of state abstention, which prevailed throughout the inter-war period, was abandoned on reclaimed land. Politicians and experts perceived these territories as a clean slate on which they could experiment with new forms of government intervention. This article focuses on state policies of social planning and the technocratic governance of reclaimed land, and examines whether these could be reconciled with democratic notions of sovereignty and citizenship in the minds of the planners, the politicians and, last but not least, the pioneers themselves.