Are the current On-site Stormwater Detention (OSD) policies the best solution for source control stormwater management? A case study of Australian and Brazilian cities

In recent decades On-site Stormwater Detention (OSD) systems have been implemented in many cities around the world. However, a few studies have evaluated the effectiveness of OSD policies. Therefore, this paper compared the use of OSD in Australian and Brazilian cities, evaluating aspects of regulations, technical details and management matters. The results showed that Australian OSD design guidelines are a few steps ahead of Brazilian manuals. However, it is not possible to affirm that the catchment-based approach, adopted by most Australian councils, is better than the site-based approach, embraced by Brazilian cities, since neither is supported by monitoring data of real OSD performance. In general, all municipalities have the same management problems. There is no control over the number of OSDs built in the cities or even the conditions of the systems. Thus, the authors proposed some directions on how OSD policies could be improved.

近几十年来，场地雨水滞留（On-site Stormwater Detention, OSD）系统已在全球诸多城市得以应用。然而，当前仅有少量研究对OSD政策的实施效能开展评估。据此，本文对比了澳大利亚与巴西两国城市的OSD应用实践，从法规规范、技术细节与管理维度展开系统评估。研究结果显示，澳大利亚的OSD设计指南相较于巴西的同类手册，整体领先数个层级。然而，由于二者均缺乏真实OSD运行性能的监测数据支撑，因此无法断言澳大利亚多数市政部门采用的集水区导向型方案，优于巴西城市所推行的场地导向型方案。总体而言，两国市政均面临相同的管理困境：既未对城市内已建成OSD的数量进行管控，也未对系统的运行状态实施监管。据此，本文作者就如何优化OSD政策提出了若干改进方向。