1. Watershed Characterization System (WCS) and its Modeling Extensions
Brian Watson
Tetra Tech Inc.

2. What Is WCS?
Customization and enhancement of EPA BASINS for EPA Region 4
Uses ESRI ArcView-GIS 3.x as a platform
Desktop system
Automated characterization report using spatial databases
Differences between BASINS and WCS
At present, WCS uses only EPA region 4 data, but can be customized for any state
WCS supports various extensions such as Sediment tool, Mercury tool, SWMM, NPSM and LSPC
WCS does not support PLOAD and SWAT

3. WCS Uses Basic system (core) Enhanced system
Characterize watersheds
Evaluate water quality conditions
Assess potential sources of impairment
Enhanced system
Add Extensions which increase WCS capabilities
In general, WCS is a repository for watershed data and assessment tools to support TMDL and other environmental programs

4. WCS Characterization Reports
Tools
Automated reports
Maps and Tables
Environmental Data

5. WCS Extensions Core watershed data and assessment tools Extensions
Additional Menu functions
Additional Datasets
Additional System files
Supported Models

6. WCS Extensions Models Sediment tool Mercury tool
SWMM model GIS interface
NSPM model GIS interface
LSPC model
Utilities
NHD download tool
Manual and auto delineation watershed tool
WRDB extension

7. Sediment Tool – Overview
Input
WCS Core + Sediment Tool
Output
BMP
Stream
Road
Elevation
Soil
Land Use
Erosion Maps
Sediment Delivery Maps
Sediment Delivery to Assessment Points
Automated Reports (Maps and Tables)
USLE Equation
4 Sediment Delivery Methods
Transport Routing Algorithm

8. Sample Results: BMP & Erosion - Little River Watershed K, GA
Before, no BMP, erosion = 1032 US tons. Dark orange color indicates high Erosion.
After, applying a BMP to row crop areas, P = 0.65, erosion = 851 US tons, an 18% reduction.
BMP area

9. Mercury Tool: Overview
Algorithms in the WCS Mercury Extension
Sediment Yield
Calculation
Hydrology
Soil Mercury
Concentration
Mercury Load •
Deposition on water and impervious surfaces
Loads from runoff and sediment (pervious surfaces)
Loads from point sources
Land use and USLE
parameters
Delivery
algorithms
Local climate,
land use, and soil
Chemistry
Dry + wet
deposition

10. Mercury Tool: Sample Results
Mercury Loading in Savannah River Basin

11. SWMM GIS Interface: Overview
WCS GIS + VB Interface + SWMM Model = WCS SWMM
Rainfall.dat
Runoff.dat
Transport.dat
SWMM Model
(PCSWMM)
Input Text Editor
Output Visualization
Files.ini
Land use
Stream Network
Station Rainfall
Data
WCS GIS Interface
VB Interface
PCSWMM

12. SWMM GIS Interface: Link to PCSWMM
PCSWMM was developed by Computational Hydraulics International (
SWMM blocks (modules) are represented by graphic objects.

13. WCS-LSPC GIS Interface: Overview
WCS automatically prepares LSPC database (shapefiles and MS Access tables) for delineated watersheds.
LSPC uses WCS prepared database to generate model input files.
One-way
WCS (ArcView GIS)
LSPC (MapObjects and MS Access)

14. Conclusions:
WCS is an extremely versatile framework for environmental databases and models
WCS (and BASINS) can be customized to many different uses beyond just TMDLs

15. How to Obtain WCS and Its Extensions
WCS Web Site:

16. WCS Web Site
WCS Web Site

17. WCS Web Site
Download WCS Documentation

18. WCS Web Site
Download WCS Data by Map or HUC

19. Demonstration of WCS Extensions TN-WCS Extension WCS to LSPC Extension
Will show how individual states can customize WCS (Tennessee Example)
Perform a simple watershed characterization with Tennessee specific datasets
WCS to LSPC Extension
Use Flint Creek Watershed (Alabama) as example