FDEP Stevenson Creek Water Quality Model (FL, USA)

A watershed pollutant loading model and a receiving water quality/ hydrodynamic model for dissolved oxygen and nutrients were setup, calibrated, and validated. These models were used to develop TMDLs for the tidally influenced and impaired segment of Stevenson Creek, Florida (WBID 1567). DSI conducted the receiving water quality modeling component of the project.

A three dimensional water quality model of the tidally influenced reach of Stevenson Creek was developed using the EFDC model. The water quality model simulated the full nitrogen and phosphorus components, as well as the carbon/BOD loadings to the creek. The impact due to actual discharges from the Marshall Street Advanced Wastewater Treatment Plant was incorporated.

The EFDC model flow boundary conditions were linked to the flow and nutrient loadings from the HSPF provided results. CDM conducted the HSPF calibration/validation work. The HSPF/EFDC linkage was streamlined using the latest updates to EFDC_Explorer. Once calibrated (2004) and validated (1999-2002) the model was completed, the TMDL base for the period 1999 to 2006 was setup. This model was then used by FDEP to develop the recommended dissolved oxygen and nutrient TMDLs for Stevenson Creek.