Obtaining Soil Type Data from the EPA

The EPA offers STATSGO soil type data in one large "core data" download.  One advantage of the EPA's data is that the land use and soil type data are included together in one download.  The steps for obtaining the soil data are outlined below.

First, locate the HUC number for your watershed area from the EPA's Locate Your Watershed website.  
Second, go to the EPA BASINS Data HUC Index web site.   If the link does not work, follow the bulletted steps below:

• Go to www.epa.gov.
• Click on the Information Sources link at the left.
• Click on the Databases and Software link.
• Click on the Geographic Information Systems link.
• Click on the Better Assessment Science Integrating Point and Nonpoint Sources (BASINS) link.
• Click the Web Download link.
• Scroll down and choose the http://www.epa.gov/waterscience/ftp/basins/gis_data/huc link, found under the heading "Basins 3 Data from the Web."

1. Go to the Locate Your Watershed website,
   The website offers four methods of searching for your area's HUC:
    -    Search by Map...click on a map of the United States to locate the area
    -    Find place...perform a quick search based on a single keyword.
    -    Places...use the USGS GNIS website to find your area.
    -    Locate by geographic unit...enter the area's zip code, state, county, tribal nation, watershed
         number or stream name.
   This example will use the Search by Map method,
2. Click on the Search by Map link,
3. Click on a state,
4. Click on the EPA hydrologic unit that covers your watershed,
   You may need to download more than one EPA hydrologic unit to completely cover your area.  If you find it difficult to ascertain which unit covers your watershed, try using another another search method, such as Find place, for example.
5. Make a note of the 8-digit USGS Cataloging Unit number located just under the Watershed Profile heading,
   This is the HUC number.
6. Go to the EPA's HUC Index,
7. Locate and click on the folder named with your 8-digit HUC,
8. Click on the file named with your HUC followed by "_core.exe,"  (Example: 16020203_core.exe) and in the ensuing dialog, save the file to your computer,
   The downloaded file is a self-extracting zip file.
9. Double click on the saved file to open the "Winzip Self-Extractor" dialog.
10. Specify a location on your computer to where you'd like the files extracted, or unzipped, and then click the Unzip button.

For computing composite Curve Number and/or Runoff Coefficient calculations with WMS, you will need to join the Hydrologic Soil Group field, hydgrp, found in the statsgoc.dbf file to the statsgo.shp file using the spreadsheet template provided below, or a GIS application such as ArcView^®.

statsgoImport.xls Template

This template contains a VBA macros designed to open both the statsgo and statsgoc tables into a spreadsheet.  Then with a single click, users can join the hydgrp field from the statsgoc table to corresponding records in the statsgo table.

Click here to download the statsgoImport zip file, which contains the template and its readme file
Be sure to view the readme.txt file for instructions on using the template.

Click here for a brief description of how to join the hydgrp field to the soil type shapefile using ArcView GIS (3.x).