The scientific and engineering literature lacks information on the possibility of using constructed wetlands (planted soil filters) within land properties with unfavourable dimensions, shapes and steep slopes. The lack of sufficient solutions enabling efficient wastewater management at such locations is not conducive to environmental protection or comfortable living conditions. The aim of the article is to review traditional planted soil filters and assess the possibility of their adaptation to difficult terrain conditions, e.g. steep erosion slopes. The need to maintain a sufficiently large active area of the bed system while simultaneously reducing the land area occupied by these beds was the basic criterion for the analyses. The article proposes new eco-technologies. These include planted shelf and step soil filters. The proposed solutions are based on gravitational flow of wastewater and self-purification processes (physical, biological and chemical processes). They can operate as horizontal subsurface flow systems and hybrid systems (horizontal and vertical subsurface flow). Filter structures also provide the stabilisation and safeguarding of the ground against erosion. A retaining wall with a footing (shelf filter) and gabion baskets and mattresses (step filter) are the basic elements of technical soil protection. The analysed solutions are examples of sustainable use of space.