The spatial structure of the Randstad Holland is strongly related to the policy concerning hydraulic engineering in the Netherlands. Both, Randstad Holland and the large hydraulic works, can be considered as part of the ‘modern project’ of the Netherlands, undertaken in the nineteenth and twentieth centuries. This modern project aimed to up- grade the Netherlands as a modern welfare state, based upon an industrial economy and agricultural autonomy, and fitting in a coherent policy of the nation-state. These days, the societal as well as the economic and the climate context of the Netherlands are changing. The new Delta-program, started in 2008, should be considered in this changing context. The potential meaning of this program is that it should not only be regarded as a provision of a new, proper flood defence infrastructure. It can play a substantial role in the transition to a new spatial, economic and political structure of the Netherlands.