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NATIONAL HYDROGRAPHY DATASET
Description:
Resource Purpose: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. The NHD is based upon the content of USGS Digital Line Graph (DLG) hydrography data integrated with reach-related information from the EPA Reach File Version 3 (RF3). While initially based on 1:100,000-scale data, the NHD is designed to incorporate and encourage the development of higher resolution data required by many users. USGS maintains the NHD database, while EPA uses a copy stored in its Reach Address Database (RAD) for its applications.
Legislation/Enabling Authority:Clean Water Act
Supported Program:All OW programs and others in different program offices as well, e.g., OPP.
Data Type:
Primary Data Type:
Other
Mapping Data
Geographical Data Stored By:
Latitude - Longitude
National Hydrography DataSet
Other
Data Represented By:
Points
Lines
Polygons
Measurement Methods:
Map compilation, GPS, map interpolation, GIS hydrologic coverages (1:100,000 and 1:24,000 scale)
System Access Privileges:
Access Methods:
Resource Website
FTP
Update Methods:
FTP
Other
Other Methods:
E-mail
Resources Accessible By:
Public
States
Regions
DataSubs
All EPA
Resources Updatable By:
DataSubs
EPA Authorized
Other
Contractor team
CBI Security:
No
Data Collection:The NHD will accept updates whenever they are submitted by cooperators.
Range of Data Start:
1999
Range of Data End:
Present