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USGS Streamgages Linked to the Medium Resolution NHD

Metadata Updated: March 5, 2024

The locations of approximately 23,000 current and historical U.S. Geological Survey (USGS) streamgages in the United States and Puerto Rico (with the exception of Alaska) have been snapped to the medium resolution National Hydrography Dataset (NHD). The NHD contains geospatial information about mapped surface-water features, such as streams, lakes, and reservoirs, etc., creating a hydrologic network that can be used to determine what is upstream or downstream from a point of interest on the NHD network. An automated snapping process made the initial determination of the NHD location of each streamgage. These initial NHD locations were comprehensively reviewed by local USGS personnel to ensure that streamgages were snapped to the correct NHD reaches. About 75 percent of the streamgages snapped to the appropriate NHD reach location initially and 25 percent required adjustment and relocation. This process resulted in approximately 23,000 gages being successfully snapped to the NHD.

This dataset contains the latitude and longitude coordinates of the point on the NHD to which the streamgage is snapped and the location of the gage house for each streamgage. A process known as indexing may be used to create reference points (event tables) to the NHD reaches, expressed as a reach code and measure (distance along the reach). Indexing is dependent on the version of NHD to which the indexing is referenced. These data are well suited for use in indexing because nearly all the streamgage NHD locations have been reviewed and adjusted if necessary, to ensure they will index to the appropriate NHD reach.

Flow characteristics were computed from the daily streamflow data recorded at each streamgage for the period of record. The flow characteristics associated with each streamgage include:

First date (year, month, day) of streamflow data Last date (year, month, day) of streamflow data Number of days of streamflow data Number of days of non-zero streamflow data Minimum and maximum daily flow for the period of record (cubic feet per second) Percentiles (1, 5, 10, 20, 25, 50, 75, 80, 90, 95, 99) of daily flow for the period of record (cubic feet per second) Average and standard deviation of daily flow for the period of record (cubic feet per second) Mean annual base-flow index (BFI) computed for the period of record (fraction, ranging from 0 to 1) Year-to-year standard deviation of the annual base-flow index computed for the period of record (fraction) Number of years of data used to compute the base-flow index (years)

The streamflow data used to compute flow characteristics were copied from the NWIS-Web historical daily discharge archive ( on June 15, 2005.

Access & Use Information

Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

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Metadata Created Date June 1, 2023
Metadata Updated Date March 5, 2024

Metadata Source

Harvested from DOI EDI

Additional Metadata

Resource Type Dataset
Metadata Created Date June 1, 2023
Metadata Updated Date March 5, 2024
Publisher U.S. Geological Survey
Identifier USGS:d4d13c9d-dc52-4fc9-b8f6-cc42ce9b1a10
Data Last Modified 20201117
Category geospatial
Category Tag 16E15F51 D96E 4051 9124 75665Abdc6Ff "Ecosystem Vulnerability","Atmospheric, Earth and Ocean Sciences"
Public Access Level public
Bureau Code 010:12
Metadata Context
Metadata Catalog ID
Schema Version
Catalog Describedby
Harvest Object Id d156f1d5-6c5a-47fa-9d88-bba687125c5c
Harvest Source Id 52bfcc16-6e15-478f-809a-b1bc76f1aeda
Harvest Source Title DOI EDI
Metadata Type geospatial
Old Spatial -159.750305,17.956547,-65.302468,48.999946
Publisher Hierarchy White House > U.S. Department of the Interior > U.S. Geological Survey
Source Datajson Identifier True
Source Hash 08c63269299b3aa02a8eeb842ef41d56bb598c011f4cf0a29511bf1baab5a1eb
Source Schema Version 1.1
Spatial {"type": "Polygon", "coordinates": -159.750305, 17.956547, -159.750305, 48.999946, -65.302468, 48.999946, -65.302468, 17.956547, -159.750305, 17.956547}

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