When a major storm event hits, RAFT provides the benefits of bioretention while conforming to constrained spaces. As RAFT collects accumulated runoff, it pre-treats it through a sediment/debris removal tray. A site and soil-specific plant community will then filter and retain the stormwater runoff, as well as remove potentially harmful nutrients while the accumulated runoff slowly infiltrates into the gravel and soil beneath it (or returns to the drainage system post-filtration through an underdrain connection). RAFT can also be connected to auxiliary storage features as shown to capture excess stormwater in more severe storm events.
This custom-built bioretention brought an attractive and functional stormwater feature at an intimate scale. These flow-through planters were both innovative and educational in the continued development of the RAFT solution. While the finished product has proven effective, the custom design and construction required a substantial effort and skill to complete.