Water Quality Modeling

Water Quality Models are being increasingly used to help understand the effect of pollutants on waterbodies. Models help us understand the movement of pollutants from land-based sources to a waterbody (watershed model) or help us understand the fate, transport, and degradation of pollutants within a waterbody. DWQ may use water quality models to help evaluate the effects of a new or expanded waste water discharge, or model the reduction of pollutants needed to restore good water quality to a lake.

The Modeling and TMDL Unit is often involved in models that are developed in support of a Nutrient Management Strategy, or TMDL load allocations. Third party models associated with a NPDES permit also require review by the MTU.                                                                            

Model Requirements
DWQ requires the following for models submitted to DWQ for decision making purposes: 

1. The person(s) planning to develop the model must have a scoping meeting with the MTU. This will ensure that the model will include all parameters needed to enable DWQ to confidently use the model results.
2. The model used must be listed in EPA's TMDL Modeling Toolbox, or the model code must remain available to the public.
3. A modeling report or other appropriate documentation, along with all associated modeling files, must be submitted to DWQ for review. 

DWQ Developed Models:

• Falls Lake Watershed Assessment Risk Management Framework (WARMF) Model (Watershed Model Report)
• Falls Lake Environmental Fluid Dynamics Code (EFDC) Model (Lake Model Report)

Models developed under contract:

• Lower Cape Fear River EFDC Model
• Jordan Lake Generalized Watershed Load Function (GWLF) Watershed Model Report
• Jordan Lake EFDC-WASP Lake Nutrient Response Model
• High Rock Lake Hydrological Simulation Program Frotran (HSPF) Watershed Model (under development)
• High Rock Lake EFDC-WASP Lake Nutrient Response Model (under development)

Modeling Resources

• Modeling program downloads