Stormwater Treatment Area 5 (STA-5) is one of six large constructed wetlands to remove excess nutrients from runoff prior to discharge into Everglades Protection Area (EPA). STA-5 consists of three flow-ways across six treatment cells covering 6,095 acres of effective treatment area. This paper presents a two-dimensional flow dynamic modeling of vegetated treatment cell 1A in STA-5 using a finite-element model, FESWMS. In this study, depth-varied Manning's roughness coefficients and material-based eddy viscosities were applied in the depth-averaged model to consider the vegetative drag according to vegetation distribution (species, density and population). The sudden changes in topography also impose significant effects on shallow water flow in cell 1A due to existence of ridges and sloughs. In order to investigate the effect of topography, two sets of ground survey (before and after ridge excavation and slough refill) were used in the FESWMS model for comparison. This study showed that vegetation and sudden change in topography make the flow pattern more complex and less predictive. The mesh density was increased at the transient area of two vegetation coverages and at the area with significant ground differential. The results using depth-varied Manning's coefficients were comparable to those using material-based eddy viscosities in qualitative estimation of vegetative drag resistance.
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