Water Oriented City—A ‘5 Scales’ System of Blue and Green Infrastructure in Sponge Cities Supporting the Retention of the Urban Fabric

The article presented methods of urban development in terms of the application of the ‘sponge city’ concept, as well as the possibility of introducing different hydro-engineering solutions into the urban fabric that allow infiltration and retention at various scales of spatial planning. The aim of the paper was to indicate which specific solutions can be used in the city in multi-dimensional and multi-functional systems. As a result of the research, the concept of a ‘5-scales’ diffusion of blue–green infrastructure elements was presented. Elements of this system are based on multi-scale blue–green infrastructure, creating a patchwork of ‘blue connections’ that fit into the city ‘green’ natural system and have a connection with urban rainwater drainage. These five elements together allow for the infiltration and retention of rainwater, and can be used in the design of ecologically sustainable water-oriented cities in the future.