Abstract
Swales are a type of sustainable urban drainage system that have been used for over two decades globally to provide stormwater conveyance and improve stormwater quality. The main design objectives of swales, and the purpose of their installation, can often vary considerably from country to country. This paper presents a brief overview of four different swale case studies from the Netherlands, Germany, Norway and Australia. The environmental conditions at each of the four swale locations, the main design objectives, the swale performance and the results of preliminary monitoring are examined. In the Dutch and German studies, the main purpose of swales was to improve hydraulic performance, that is, to reduce velocities of stormwater runoff and increase storage capacity. In the Norwegian and Australian studies, there was an additional focus on improving the quality of stormwater runoff. In all cases, swales were shown to be effective. However, to achieve the desired objectives and ensure that the required swale performance is achieved; it is recommended that some basic guidelines are followed.