Application of MIKE SHE/MIKE 11 Model to Structural BMPs in S191 Basin, Florida

Abstract

The S191 basin contributes significant phosphorous (P) loads to Lake Okeechobee, Florida (the Lake). This basin is located northeast of the Lake, and extensive nonstructural and structural Best Management Practices (BMPs) have been implemented to reduce total P (TP) loads. The Davie Dairy Best Available Technologies (Davie Dairy BAT) and The Taylor Creek Stormwater Treatment Area (Taylor Creek STA) are two of the structural BMP projects. The Taylor Creek STA reduces P loads to the Lake through detention, plant growth and soil sorption. The Davie Dairy BAT project reduces the P loads to the Lake through detention and chemical treatment. The objective of this study was to develop a model tool to simulate the structural BMP projects'daily flow rate and long term treatment volume under different weather scenarios. The MIKE SHE/MIKE 11 coupled model was selected for this study because of its capability to simulate the dynamic exchanges between the overland flow plain, groundwater system, and the river system. This study developed, calibrated and validated a MIKE SHE/MIKE 11 coupled model for this basin. The simulated daily flow rates at structure S191 compared favorably with measured values for a calibration and validation time period. Simulated groundwater levels for calibration were reasonably consistent with the measured groundwater levels. The calibrated and validated model was applied for long term simulation to evaluate the two structural BMP projects'long term treatment performance, annual average TP load reduction, using the observed hydrology and the water quality data.