In Gennany and elsewhere, discussion of alternative methods of urban stonnwater management have led to the belief that an economically and ecologically sound combination of central and distributed methods will be the concept of the future. However introduction of methods other than traditional combined sewer systems has been limited by the shortage of planning tools and technologies. Adding a number of frequently used better stonnwater management practices (BSMPs) has widely extended the use of an existing stonnwater water balance and pollution load model.