Bioretention basin best practice design guidelines

Abstract

[Abstract]: A ‘best practice’ design guideline for a bioretention basin is concluded by comparing and critically evaluating existing design guidelines, along with studies on their performance. Further, an appropriate naming convention for a bioretention basin is sought and concluded. Bioretention basins (which are an aspect of Water Sensitive Urban Design) seek to maintain near-to natural flow levels at storm water receiving waters (by retention of storm runoff) and treat storm runoff to remove pollutants at-source in urbanised areas. This minimises the consequences on receiving waterways caused by urbanisation. The increase in impervious area in an urbanised area causes disruption to the natural hydrologic cycle and an increase in stormwater pollutant load. Many different guidelines exist for bioretention basin design due to simultaneous evolution of the technology in various locations around the world. A consensus on ‘best practice’ design principles is needed. The design guidelines of bioretention basins are easily divided into separate design elements. This enables comparison and critical evaluation to be undertaken in terms of each design element to conclude an overall ‘best practice’ design guideline for the system. Recommendations for further research into some of these design elements are presented due to conflicting information in the publications reviewed or a lack of information. Twelve design guidelines and twelve studies from the USA and Australia are used as a source of information. The naming convention is also compared in the various publications reviewed and other literature. The most appropriate term for a bioretention basin is ‘bioretention’ followed by either ‘basin’, ‘system’, ‘cell’, ‘area’ or ‘facility’. A ‘best practice’ design guideline has been concluded. It shares many similarities to some of the existing design guidelines, giving it some merit. Field testing is recommended to research its effectiveness.