Improved hydraulic performance for designed detention ponds and treatment wetlands may be achieved by the placement of island clusters near the inlet, according to a study using scaled physical models. The models showed maximum pollutant removal with islands occupying 10% of basin volume.
Balderas Guzman, Celina, Samantha Cohen, Manoel Xavier, Tyler Swingle, Waishan Qiu, and Heidi Nepf. “Island topographies to reduce short-circuiting in stormwater detention ponds and treatment wetlands.” Ecological Engineering 117 (2018): 182-193. https://doi.org/10.1016/j.ecoleng.2018.02.020.