California Water and Environmental Modeling Forum

Promoting Excellence and Consensus in Water and Environmental Modeling


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U.S. EPA TMDL Modeling Toolbox

Thursday, July 29, 2004
9:30 a.m. to 4:30 p.m.

Joe Serna Jr. Cal-EPA Building
 “Central Valley” Hearing Room (2nd Floor)
1001 “I” Street, Sacramento, CA


Presented by Tim Wool, U.S. EPA Watershed and Water Quality Modeling Technical Support Center, Athens, Georgia, and Steven Davie, Tetra Tech

Over the past five years, EPA Region 4 and Tetra Tech, Inc. have developed thousands of TMDLs from simple to complex types for various pollutants and stressors.  The components in the EPA TMDL Toolbox are the public domain models and tools that were primarily used in this TMDL development effort.  These tools have been updated to make the TMDL analytical process easier (you still need to provide the brain power and common sense) and modified to assure the tools can transfer information and data among the various components.  Each tool can be used independently from the other tools, so other models or analytical methods can be used.

The TMDL Modeling Toolbox is a collection of stand alone models for dynamic simulation of hydraulics and water quality in surface waters, including overland flow, streams, rivers, lakes, estuaries, coastal embayments and offshore. The overall design criterion is modular with “plug and play” capability for incorporation of future models and tools. All of the models in the Toolbox have a proven record in TMDL determination.

This workshop will expose the participants to various modeling tools and approaches that have been integrated to allow the rapid development of TMDLs using the various components of the Toolbox.  The workshop will cover brief background information about the various modeling tools in the toolbox; how the tools are integrated; and case study examples that participants can follow.


      TIME                              TOPIC                

  9:30 – 10:00           Introduction to the TMDL Modeling Toolbox

 10:00 – 10:30           Water Resource Database (WRDB)

  • Overview
  • Demonstration – Flint Creek AL
    • Summary Tables, Summary Statistics, Time Series Graphs, Low-Flow Analysis, Histograms
  • Integration with other models

 10:30 – 11:00          Watershed Characterization System (WCS)

  • Overview
  • Integration with other tools
  • WCS Extensions
  • Demonstration
    • Customized Tennessee WCS
    • WCS to LSPC (Flint Creek example)
  • WCS Extensions

 11:00 – 12:00           Loading Simulation Program in C++ (LSPC)

  • Overview
  • Demonstration – Flint Creek AL
    • WCS Inputs
    • Model Inputs
    • Model Outputs
  • Integration with other tools

 12:00 – 1:00             LUNCH

 1:00 – 2:00               Environmental Fluid Dynamics Code (EFDC)

  • Overview
  • Grid Generator – build grid for Flint Creek AL
  • Preprocessor – setup EFDCView for Flint Creek AL
  • Run EFDC for Flint Creek AL

 2:00 – 2:15               Postprocessor (MOVEM) of Results

 2:15 – 3:00              Water Quality Analysis Simulation Program (WASP6)

  • Overview
  • Utility Tools
    • Preprocessor
  • Demonstration – Flint Creek AL
  • Linkage of EFDC to WASP (HYD file)
  • Recent WASP additions:
    • Sediment Oxygen Demand
    • Periphyton
    • Multiple Component BOD
    • Compressed hydrodynamic linkage file

 3:00 – 3:15               BREAK

 3:15 – 4:00               WASP6 continued

 4:00 – 4:30               Wrap-Up and Other TMDL Toolbox Tools