A substance flow analysis of the stormwater system in Vasastaden in the city of G\uf6teborg has been carried out using a substance flow model called SEWSYS. The model handles fluxes of substances within an urban catchment and keeps track of each substance; where it originates and where it finally ends up. The present sewer system has been studied and the status of sustainability evaluated. Different abatement measures to achieve a system with more sustainability have been modelled and evaluated. The measures include source control and end-of-pipe solutions. From this study it may be concluded that all the studied measures individually lead towards a very high reduction of the discharges of pollution to the water body, but the source control measures are recommended as a first choice since they by definition are sustainable