Freshwater scarcity has become a growing global problem. Due to global warming, a change in the water resources management is necessary. The Water Wall is an example of a building component that combines an innovative approach to water retention with modern design and ecology. It is a retention reservoir located on the facade of the building, allowing to collect rainwater. The component is made of ecological materials - recycled plastic. It can be used in various scales, from small individual objects to the urban scale, where it can cover entire frontages.