Our aim is to deal with the fact of loosing the control of the ground floor with its normally functioning as circulation, working and public space during flooding. The units designed for this purpose provide a new circulation level. Unit:The construction is a very elementary pillar-slab construction in concrete. The units variate slightly in three types, having on the first floor either a totally open public floor, a semi open public space or an inner private closed core and a surrounding public circulation space. The ground floor can be used for public or temporary uses, which can easily be given up during flooding. The upper floors are convenient for living and sleeping rooms. The different types of the unit are supposed to work like a puzzle, providing a continuous public space for circulation which can be activated during flood period. Pontoon: To complete the circulation system over a street we designed bottle pontoons, which can be easily used to cross the flooded street and to connect the several open spaces on the first floor of the units.