EPA Environmental Dataset Gateway


Open/Close section Identification Information
Title: NHD Flowline, California, 2007, NHD
Abstract: The National Hydrography Dataset (NHD) is a feature-based database that interconnects and uniquely identifies the stream segments or reaches that make up the nation's surface water drainage system. NHD data was originally developed at 1:100,000-scale and exists at that scale for the whole country. This high-resolution NHD, generally developed at 1:24,000/1:12,000 scale, adds detail to the original 1:100,000-scale NHD. (Data for Alaska, Puerto Rico and the Virgin Islands was developed at high-resolution, not 1:100,000 scale.) Local resolution NHD is being developed where partners and data exist. The NHD contains reach codes for networked features, flow direction, names, and centerline representations for areal water bodies. Reaches are also defined on waterbodies and the approximate shorelines of the Great Lakes, the Atlantic and Pacific Oceans and the Gulf of Mexico. The NHD also incorporates the National Spatial Data Infrastructure framework criteria established by the Federal Geographic Data Committee.
Purpose: The NHD is a national framework for assigning reach addresses to water-related entities, such as industrial discharges, drinking water supplies, fish habitat areas, wild and scenic rivers. Reach addresses establish the locations of these entities relative to one another within the NHD surface water drainage network, much like addresses on streets. Once linked to the NHD by their reach addresses, the upstream/downstream relationships of these water-related entities--and any associated information about them--can be analyzed using software tools ranging from spreadsheets to geographic information systems (GIS). GIS can also be used to combine NHD-based network analysis with other data layers, such as soils, land use and population, to help understand and display their respective effects upon one another. Furthermore, because the NHD provides a nationally consistent framework for addressing and analysis, water-related information linked to reach addresses by one organization (national, state, local) can be shared with other organizations and easily integrated into many different types of applications to the benefit of all.
Open/Close section Distribution Information
Resource(Server) URL: http://edg.epa.gov/
Download URL: ftp://nhdftp.usgs.gov/SubRegions/
Open/Close section Time Period of Content
Publication Date: 20070920
Progress: In work
Frequency: irregular
Open/Close section Single Date
Date: 20070920
Currentness: See dataset specific metadata.
Open/Close section Spatial Domain
West Bounding Longitude: -124.409590
East Bounding Longitude: -114.588480
North Bounding Latitude: 42.009510
South Bounding Latitude: 32.534160
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Open/Close section Constraints
License https://edg.epa.gov/EPA_Data_License.html
Access: None
Use: None. Acknowledgment of the originating agencies would be appreciated in products derived from these data.
Open/Close section Theme Keywords
Theme Topics: Canal / Ditch, Lake / Pond, Hydrography, Stream / River, Spring / Seep, Swamp / Marsh, FWHYDROGRAPHY, Artificial Path, Reservoir, Reach Code
Open/Close section Contact Information
Originator: U.S. Geological Survey in cooperation with U.S. Environmental Protection Agency, USDA Forest Service, and other Federal, State and local partners (see dataset specific metadata under Data_Set_Credit for details).
Email: ask@usgs.gov
Address Type: mailing address
City: Reston
State: VA
Postal Code: 20192
Telephone: 1 888 ASK USGS
Open/Close section Metadata Reference Information
File Identifier: {4EEA1311-5048-4AF8-8FEF-9914A3F553D0}
Metadata Date Stamp: 2007-09-20
Metadata Standard Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata Standard Version: FGDC-STD-001-1998