Instructions for using the NHD Download Tool

1) Load the extension called Tetra Tech's NHD Download Tool from the File->Extensions Menu in
   ArcView. (You will not see the extension if you have not copied the TtNHDDownload.avx from 
   the installion folder to the Arcview Extensions(Ext32) folder).
2) A new view called NHD Download view will be created in the project and a file dialog will promt
   you to open the cataloging units shapefile. You can download the cataloging units shapefiles for
   each EPA region from our website.
3) Once you have the view and the cataloging units theme in the view, you can use the button(arrowhead pointing
   downwards) created by the extension to go through the rest of the download process.
4) If you are using the cataloging units theme downloaded from our website, you can use the 
   default values in the dialogs. If you are using some other cataloging unit theme, you will
   have to select the appropriate theme and 'Cu' fields in the dialog.
5) Note that the units of the downloaded NHD shapefiles are decimal degrees.

Tetra Tech, Inc.
February 18th, 2002.

Contact: Henry Manguerra at henry.manguerra@tetratech-ffx.com
				or
	 Vaishal Sheth at vaishal.sheth@tetratech.ffx.com