Depressional wetland hydrologic dynamics in the Okeechobee basin, FL are not well understood. Management of these wetlands is related to landscape-scale reduction of nutrient loads to Lake Okeechobee, where efforts are being made to attenuate the rate of hyper-eutrophication. Four depressional wetlands in the Lake Okeechobee catchment were instrumented and monitored for three years to estimate the components of the water budget. These wetland inflows and outflows were interpreted in terms of nominal hydraulic residence times. Groundwater, rainfall, and overland flow wetland inflows were used at the hydrologic boundary conditions, while groundwater outflow, evapotranspiration, and surface water outflow were the outflow boundary conditions. Nutrient uptake was assumed to be a first-order process and chemical flux to the wetland (nutrient loading) was considered uniformly distributed around the perimeter of the wetland at a constant concentration. The analytical solution for the advection-dispersion equation for a continuous input of chemical was applied to multiple, linear flow pathways originating from specific points around the perimeter of standing water in the wetland to the ditch outflow. This result was compared to the assumption that the wetland follows the behavior associated with a series of continuously stirred tank reactors having a similar uptake coefficient. The hydraulic residence time distribution was bimodal, due to the difference in magnitude and occurrence of surface water outflow compared to the groundwater outflow. There was a significant difference between treatment efficiency estimates between methodologies (30% using multiple flow path estimates versus 19% using the tanks-in-series approach). The transient hydrologic nature of these wetlands creates conditions that are challenging to numerically simulate for wetland treatment efficiency; however, it is crucial to begin to quantify the present and future potential of these naturally-occurring landscape features.