Obtaining Hydrologic Data through the Internet


Digital Elevation Models (DEMs)

Three Arc Second DEMs of the United States

What are 3" Digital Elevation Models?

Fifteen Arc Second DEMs of the United States

What are 15" Digital Elevation Models?

Thirty Arc Second DEM of the World (GTOPO30)

What are 30" Digital Elevation Models?

How to download a 30" DEM


Digital Line Graphs (DLGs)

1:2,000,000 DLGs

What are 1:2,000,000 Digital Line Graphs?

1:100,000 DLGs

What are 1:100,000 Digital Line Graphs?


Hydrologic Unit Codes (HUCs)

What are Hydrologic Unit Codes?

Quick Connect to HUCs Web Site


Land Use/Land Cover Files (LULC)

What are Land Use/Land Cover Files?

Quick Connect to EPA LULC Web Site

A process for obtaining the LULC files from the EPA

Quick Connect to USGS LULC Web Site


River Reach Files (RF1)

What are River Reach Files?