Services Rendered:

TMDL Model Development

TMDL Support

EFDC 3D Water Quality Modeling

HSPF Modeling


Waste Load Allocations

A system of watershed pollutant loading models and a receiving water quality/ hydrodynamic model for application in the development of dissolved oxygen and nutrient TMDLs for the Perdido Bay were developed. Thirteen watershed models were developed for all of the inflows into the Perdido Bay, including the Perdido River, Elevenmile Creek, and Bayou Marcus. DSI conducted the Perdido Bay 3D hydrodynamic and water quality modeling component of the project and the Perdido Basin HSPF model.

A three dimensional water quality model of the Perdido Bay 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 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 Perdido Bay.