GeoSpatial Technology Program

Land Cover - CCAP, NLCD | Soils - SSURGO, STATSGO | Water Resources - HUC, NHD, NWI,
Waterbodies | Unique and Fragile - Flood Maps | Other Useful Data - NALC, NED

National Hydrography Dataset (NHD)

URL: nhd.usgs.gov/

COST: Free for download

AGENCY: USGS and EPA

FORMAT: ArcInfo Coverage

PROJECTION: Lat/Long, NAD83

DESCRIPTION: The National Hydrography Dataset (NHD) is a comprehensive set of digital spatial data that contains information about surface water features such as lakes, ponds, streams, rivers, springs and wells. Within the NHD, surface water features are combined to form "reaches," which provide the framework for linking water-related data to the NHD surface water drainage network. These linkages enable the analysis and display of these water-related data in upstream and downstream order.

DOWNLOAD: Go to edcnts14.cr.usgs.gov/Website/nhdserver/viewer.htm. The NHD map display shows the current contents of the NHD database (select the theme on the right and click refresh). NHD data can be downloaded by subbasin (formerly known as cataloging unit) at no charge. The metadata for each subbasin is available and provides information on the content of the subbasin including descriptions of updates. As NHD data are updated, users will be able to select and retrieve subbasins based upon the information found in their metadata. The summary of known problems provides additional information about the data. Once the NHD map is open and displayed use the Visible checkboxes on the right side of the screen to view one or more data layers and use the Active radio buttons to choose which layer will be selected and downloaded. Zoom to area of interest using the zoom and move tools. Use the select tools to highlight watersheds of interest. One or many can be selected using the select by rectangle tool. A list of selected subbasins is located on the center bottom of the screen. Each record has the option to click metadata or download.

CLICKING METADATA: Clicking metadata opens a new browser window that describes the data and provides a link to the EPA watershed page for that watershed. The EPA watershed page includes a Watershed Profile providing information such as websites related to the watershed, associated citizen groups, watershed health, and other available USGS data.

CLICKING DOWNLOAD: Clicking download in the download column opens a new browser that is a brief online survey that is required before data download. A download page is then displayed that shows the data to be downloaded as well as the format.

ESRI/ARC format is then selected and the user has a choice as to where to download the data. The ESRI/ARC data is zipped in tgz format. See Working with TGZ Format for instructions. If you would like to download more than one record at one time, select the records for download by checking the checkbox to the right of each record. Then click "Download Selected Datasets".

Alternative methods for downloading are available that do not use an interactive map. Go to nhd.usgs.gov/1st-trouble_downloading.html and click on "Alternate Download Methods". Note that you will need to know the CU numbers (Catalog Unit). Click on the records of interest and select "Save this file to disk."

RESULTS: The below graphic shows the NHD data for the 01080205 subbasin in Central Connecticut. The series of NHD datasets that cover Connecticut are shown in the second graphic.

Comments or Suggestions? Email us at ewilson@canr.uconn.edu.