The vision is to develop sub-surface storage that can retain stormwater like a “sponge”, i.e. to relieve the pressure on stormwater sewers in case of heavy precipitation, where space-demanding solutions are not an option. In the short-term, models will be developed and run on the theoretical functioning of such a solution. Different media will have to be researched, e.g., in terms of pollution contribution, and operations and maintenance means. Energy-efficient drying processes will have to be researched and developed. The Sponge will not be fully researched and developed within the centre’s first 5 years of operations, but research activities related to this solution, such as the ones described, are already ongoing.