Summary:

On dispersed development areas most often exists advantageous conditions for expansion and application systems in order to increase retention and water percolation on the precipitation spot. This way of rain water management has favorable influence on runoff dynamic within built-up area and adjoining roads. Possibility of infiltration systems using depends on ground water depth, kind of ground and area accessibility to build infiltration facilities. Methods of rain water management which can be used on dispersed development areas are presented in this paper. The research results of suspensions grain composition from rain water and analysis of literature data concerning runoff quality show large changeability of pollution indexes. Using of infiltration facilities permits remove majority of pollutants accumulated at suspension particles which are piled up at filtration medium surface. Knowledge of suspensions grain composition occurring in rain water allows estimate intensity of clogging process in different kind of grounds as well as select methods which protect ground against deep clogging. Maintenance operations which are made regularly in infiltration facilities leads to removing clogged layer of ground and majority of pollutions protect in this way ground water against contamination.