Comparative analysis of bioretention design strategies for urban runoff infiltration: a critical overview

This systematic review article provides a comprehensive overview of the application of nature-based solutions, specifically rain gardens, as compensatory techniques for stormwater management in various locations worldwide. A total of 53 articles, published between 2008 and 2024, were selected to identify the most utilized and advanced approaches regarding the quantitative analysis of bioretention cells for stormwater storage and infiltration. Given that this is a relatively recent topic in the context of urban drainage, with over 65% of the research published in the last five years (2020–2024), an established consensus on best construction practices, ideal materials, and suitable vegetation selection has yet to be reached. The studies are predominantly focused on temperate regions, indicating a pressing need for future investigations, particularly in tropical regions where data availability is limited. The reviewed studies highlight that the performance of rain gardens is intrinsically linked to a variety of parameters, including the confluence ratio, rainfall regime, engineering soil media composition, infiltration rate, internal layer configuration, and vegetation selection. However, despite the lack of consensus on these aspects, the analyses indicate that the implementation of rain gardens can effectively contribute to stormwater retention in urban environments. This finding suggests that, although there are gaps in the detailed understanding of the mechanisms and optimal conditions for maximum performance, there is a solid foundation for the continued use and enhancement of this practice as an effective stormwater management strategy in urban areas.