Soils in urban areas differ from natural locations regarding its composition and its property. One feature, for example, is a high fraction of rubble with artificial origin. In German cities, detrital structured soils are often to be found as an inheritance of the destruction during World War 2. This mixture of rubble and ruins was deposited as a layer which varies in its thickness between some decimeters and some meters. Nowadays these soils determine many urban sites, eg parks, court yards and fallows. Rubble is a mixture of various building materials and mainly contains brick, mortar, plaster and concrete. Compared to a skeleton of natural origin, this detrital ground structure has a distinct system of pores and therefore, has a huge influence on the waterballance of soil. For example, the pore structures of bricks differ from surrounding soil. A detrital layer is characterized by a heterogenous pore structure and by different hydraulic functions. The bases for the study are the measured hydraulic properties of debris. The water retention as well as the water conductivity were measured in a laboratory, focusing on bricks. Results indicate that those materials show a high degree of porosity, which allows a high storage capacity of water. Many of these materials also have high unsaturated hydraulic conductivity. The corresponding hydraulic functions are described by the Mualem-Van Genuchten function. The examined materials are grouped into characteristic types of hydraulic functions by cluster analysis. In order to examine the influence of detrital soil structure on the mobility and the dynamic of water, numerical studies were examined. For this aim we used the 2 dimensional simulation program DELPIN4, a tool wich is originaly used in the building climatology to simulate the coupled heat, moisture and salt transport in poruos building materials. The modeled profiles differ in the fraction of coarseness of their structure as well as their properties. The climatic boundary conditions led to phases of drying up and wetting. The results of the simulation show how patterns of water content and water flow develop, depending on the heterogeneity of hydraulic properies. Furthermore conclusions are drawn about the mobility and the supply of water in technogonem skelett. Finally, applied examination methods and simulation models are reviewed to be useful and convenient, in order to describe the regime of water flow and water exchange in such heterogenous soil.