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    • Network attributes for the High Resolution National Hydrography Dataset (NHD) based initial 3D Hydrography Program Network

    Metadata Updated: January 6, 2026

    This dataset contains the initial 3D Hydrography Program (3DHP) flow network topology, which is based on the final High Resolution National Hydrography Dataset (NHD), and a set of mainstem river identifiers based on the Medium resolution NHDPlus Version 2 (NHDPlusV2). The 3DHP flow network topology and mainstem identifiers contained in this data release add two key pieces of information to the flow table of the National Hydrography Dataset: 1) at every junction, one and only one main upstream and downstream connection has been identified 2) every "in network" flowline has been assigned a mainstem identifier that places it into a hierarchy of rivers and drainage basins. For description of 1 and 2 and additional background, see supplemental information. Files included: - HU6_mainstem_outlets.geojson Outlet locations of six-digit hydrologic units along mainstem network. - nhd_3dhp_conus_mainstems.zip Zipped table in Comma Separated Values (csv) format containing NHD permanent identifiers and mainstem Uniform Resource Identifiers (URIs) for the Contiguous United States (CONUS). - nhd_3dhp_conus_flownetwork.zip Zipped csv table containing from / to NHD permanent identifiers (from flowline to flowline) and upmain / downmain attributes for CONUS. - nhd_3dhp_conus_vpu_membership.zip Zipped csv table containing NHD permanent identifiers and which Vector Processing Unit (VPU) they belong in. - nhd_3dhp_oconus_mainstems.zip Zipped csv table containing NHD permanent identifiers and mainstem URIs for areas Outside of the Contiguous United States (OCONUS). - nhd_3dhp_oconus_flownetwork.zip Zipped csv table containing from / to NHD permanent identifiers (from flowline to flowline) and upmain / downmain attributes for OCONUS. -3dhp_flownetwork.zip Zipped csv table containing from / to 3DHP identifiers (from flowline to flowline) and upmain / downmain attributes. - nhd_3dhp_nonnetwork_mainstems.zip Zipped csv table containing mainstem identifiers for features not included in the NHD flow table. - nhd_final_registry.zip Zipped csv table containing all expected flowlines from the final NHD -- excludes geometry. - nhd_reachcode_mainstem.zip Zipped csv table containing a mapping between mainstem identifiers and NHD reachcodes. - nhd_3dhp_region_connections.zip Zipped csv table containing connections between vector processing unit regions defined by four-digit hydrologic unit. - nhd_3dhp_mainstem_summary.zip Zipped csv table containing summary information about mainstems contained in nhd_3dhp_conus_mainstems.zip and nhd_3dhp_oconus_mainstems.zip.

    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.

    Downloads & Resources

    Dates

    Metadata Created Date January 6, 2026
    Metadata Updated Date January 6, 2026

    Metadata Source

    Harvested from DOI USGS DCAT-US

    Other Data Resources

    Additional Metadata

    Resource Type Dataset
    Metadata Created Date January 6, 2026
    Metadata Updated Date January 6, 2026
    Publisher U.S. Geological Survey
    Maintainer
    Identifier http://datainventory.doi.gov/id/dataset/USGS_650cba99d34e823a0273a790
    Data Last Modified 2025-05-20T00:00:00Z
    Category geospatial
    Public Access Level public
    Bureau Code 010:12
    Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
    Metadata Catalog ID https://ddi.doi.gov/usgs-data.json
    Schema Version https://project-open-data.cio.gov/v1.1/schema
    Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
    Harvest Object Id 039fd09e-bf26-47b3-b905-fd55f1bd61df
    Harvest Source Id 2b80d118-ab3a-48ba-bd93-996bbacefac2
    Harvest Source Title DOI USGS DCAT-US
    Metadata Type geospatial
    Old Spatial -180.0000, 17.5000, -65.0000, 71.3000
    Source Datajson Identifier True
    Source Hash f8099872f042becb84f2f7294747325d5eaddad90d7a8a5bb73ff61c75eb3030
    Source Schema Version 1.1
    Spatial {"type": "Polygon", "coordinates": -180.0000, 17.5000, -180.0000, 71.3000, -65.0000, 71.3000, -65.0000, 17.5000, -180.0000, 17.5000}

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