This paper describes a case study on a new alternative drainage system for urban stormwater management, the so-called “Sandsli-system”. The aim of this study is to evaluate the Sandsli system and the effects of the solution on ground water conditions. The study is carried out in the Sandsli research catchment in Bergen, Norway. The idea behind the “Sandsli-system is not to mix the polluted and the clean stormwater combined with a source control for both stormwater quantity and quality. The clean stormwater is percolated as quickly as possible, while the polluted stormwater is collected and conducted to an appropriate site for disposal or treatment.
The Sandsli-system was developed as an alternative drainage system to the conventional drainage system. The system has been functioning satisfactorily since 1981 to date. The advantages of the use of the Sandsli-system is highlighted i.e. recharging the stormwater to the ground water. The Sandsli-system is appropriate to locations with climate and geology similar to that found in the coastal part of Norway