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Elevation Derivatives for National Applications (EDNA) Seamless Three-Dimensional Hydrologic Database


   Elevation Derivatives for National Applications
   (EDNA) nationwide hydrologic 3D database


  Graphical mountain showing elevation and streams

  Three-dimensional (vertically integrated) drainage
  derived from high-resolution digital elevation model.

Elevation Derivatives for National Applications (EDNA) is a seamless, nationwide, multi-layered three-dimensional (3D) hydrologic database derived from a version of the National Elevation Dataset.

EDNA’s 3D hydrologic layers are vertically consistent by their very nature, meaning that hydrologic drainage always flows from a higher elevation to a lower elevation and that reach catchment boundaries always follow the elevation drainage divide. This consistency allows for transfer of valuable information from digital elevation models onto EDNA-derived drainage lines and watersheds, including stream gradient, minimum and maximum elevation within a watershed, average watershed slope, and elevation.

Derivative hydrologic data have numerous environmental and hydrologic applications. EDNA can be used simply as a shaded relief backdrop, or for nationwide hydrologic modeling. The database is valuable because drainage areas upstream or downstream from any location can be accurately traced facilitating flood analysis investigations, pollution studies, estimations of annual streamflow, and hydroelectric power generation.

The EDNA database was completed from 2000–2003 as a collaborative effort between the U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center, USGS Water Resources of the United States, National Oceanic and Atmospheric Administration, National Weather Service, National Severe Storms Laboratory, and the U.S. Environmental Protection Agency.

EDNA Data Products

The collection of the high-resolution, seamless 3D EDNA database is vertically integrated with elevation data and is available in raster (grid) and vector (point, line, and polygon) layers for the conterminous United States (CONUS), Alaska (AK), and Hawaii (HI).

A graphical image of the EDNA Processing Flow Diagram

The EDNA database has floating point numeric values with the following Product Specifications. Raster data products are available in Esri ArcMap grid format. Vector data products are available in Esri ArcMap shapefile format.

Product Specifications
 Projection  - CONUS, AK, and HI  Albers Conical Equal Area
 Horizontal Datum - CONUS and HI  NAD83 (North American Datum of 1983)
 Horizontal Datum - AK  NAD27 (North American Datum of 1927)
 Ellipsoid - CONUS and HI  Geodetic Reference System 80
 Ellipsoid - AK  Clarke 1866
 Vertical Datum  NAVD88 (North American Vertical Datum of 1988)
 Vertical Units  Meters
 Spatial Resolution - CONUS  1 arc-second (~30 meters) and 1/3rd arc-second (~10-meters)
 Spatial Resolution - AK  2 arc-second (~60 meters)
 Spatial Resolution - HI  1/3rd arc-second (~10 meters)
 File Size  Varies up to 60 GB for uncompressed raster data*

*Files are compressed for data delivery.

Vector products will compress to a fairly small file size, which allows for easy download through EarthExplorer. Raster products have large files of up to 30 GB for compressed data for the conterminous United States that may time out during file transfer. Please contact to access Bulk Media for data transfer. Bulk Media Delivery provides the option to receive EDNA database products on an external drive.

Coverage Maps

Coverage Maps indicating the availability of EDNA products are available for download.

Additional Information:

Data Use and Citation Policies

For information on how to cite USGS data plus guidance on usage restrictions,
please see our Data Citations and Use page at

Any use of trade, firm, or product names is for descriptive purposes only and
does not imply endorsement by the U.S. Government.

Contact Information for User Assistance

U.S. Geological Survey (USGS)
Earth Resources Observation and Science (EROS) Center
47914 252nd Street
Sioux Falls, SD 57198-0001

Phone Number: 605-594-6151
Toll Free: 800-252-4547
Fax: 605-594-6589


Business Hours: Monday thru Friday, 8:00 a.m. to 4:00 p.m., Central Time