Sustainability of Treatment Wetlands: Stormwater Treatment Areas in South Florida.

A spatially distributed water quality model was applied to simulate spatio-temporal phosphorus (P) transport and cycling in a stormwater treatment wetland in South Florida. The critical questions evaluated in this paper are the long-term sustainability of the network of treatment wetlands constructed as part of the Everglades restoration. These wetlands used as buffers to reduce concentrations of nutrients such as P from EAA runoff before entering the adjacent natural wetlands, and together comprise the world's largest treatment wetlands. Model performance is demonstrated using historic data on P removal and in Stormwater Treatment Area 1 West (STA 1W), also formerly known as the Everglades Nutrient Removal project. The model includes transport and biogeochemical transformation of P and is based on primary mechanisms regulating P behavior in soils, water column and biomass. The model calibration was performed to fit two years of field measurements, and verified over three additional years. Predictive model scenarios are discussed that evaluate the long-term sustainability of these wetlands based on P storage and release (internal load), extreme events (e.g., hurricances), and other management considerations (such as changes in flow regime).