Brief descriptions of selected models commonly used in nutrient water quality modeling are included below, and the introductory table shows them sorted by model type: watershed model, hydrodynamic model, water quality model, and nutrient BMP (best management practice) model. These models are commonly used in concert with each other such that a watershed model may be linked to a hydrodyamic model on the same project. Thus, the examples included in the Models in Action section for each model will frequently include more than one model.

For help determining which model or models are best suited for your needs consider the Water Environment Research Foundation’s (WERF) LINK1T11 software.

The types of models commonly used in nutrient water quality modeling include:

Water Quality Models

• Describe changes that occur to contaminants (e.g., eutrophication models describe nutrient cycles; growth of algae; and production and consumption of dissolved oxygen)

Watershed Models

• Describe hydrologic mechanisms (e.g., flow)
• Describe delivery of contaminants from the watershed to a stream, river, lake, or estuary (e.g., temperature, total nitrogen, total phosphorus, total suspended solids, dissolved oxygen, biochemical oxygen demand)

Hydrodynamic Models

• Describe water movement (e.g., volume, velocity, direction); can describe the water movement in one, two, or three dimensions over varying time periods
• Simulate corresponding changes in properties (e.g., temperature and salinity)

Nutrient BMP Models

• Aid in the selection of Nutrient BMPs and forecasting of nutrient removal effectiveness and cost

Note some models fit in more than one category.

Model	Water Quality Model	Watershed Tools/Models	Hydrodynamic Model	Nutrient BMP Model
AQUATOX
BASINS
BATHTUB
BMP-DSS
CE-QUAL-W2
ECOMSED
EFDC
EPD-RIV1
HSPF
LSPC
QUAL2K
QUAL2KW
SPARROW
SUSTAIN
SWAT
SWMM
WAM
WARMF
WASP