The USGS National Geospatial Program (NGP) is starting to implement the new 3D Hydrography Program (3DHP) in Fiscal Year 2023. The 3DHP will significantly improve the level of detail, currency, and content of hydrography data by deriving updated stream networks and watersheds from high-quality 3D Elevation Program (3DEP) data. 3DHP will also improve the ability to track information about water as it moves through the hydrologic cycle.
In order to successfully implement the 3DHP, the NGP plans to phase out active updates and maintenance of the current National Hydrography datasets which consist of the National Hydrography Dataset (NHD), Watershed Boundary Dataset (WBD), and the NHDPlus High Resolution (NHDPlus HR). The transition includes phasing out the current stewardship process and discontinuing edit access to the NHD and WBD. This change is a critical step to implement the 3DHP.
The timeline to phase out active maintenance of the National Hydrography datasets is as follows:
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Markup corrections must be submitted by November 30, 2022
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Discontinue new editor training - target completion December 31, 2022
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Discontinue edit access to the NHD database - target completion December 31, 2022
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Discontinue WBD editing - target completion June 30, 2023
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Publish static versions of the NHD, WBD, and NHDPlus HR - target completion September 30, 2023
Throughout FY23, updated versions of the NHD, WBD, and NHDPlus HR will continue to be released as changes are made. At the end of September 2023, NGP will publish static versions of the NHD, WBD, and NHDPlus HR which will remain available for user applications as downloadable products and web services for several years while 3DHP is populated. The HydroAdd tool will also continue to be maintained to address water resources information to the NHD and eventually to 3DHP.
NHD and WBD
The NHD and WBD are geospatial datasets that map the Nation’s surface water network and hydrologic drainage areas. The NHD, at 1:24,000-scale or larger, represents the Nation’s rivers, streams, canals, lakes, ponds, glaciers, coastlines, dams, and streamgages, and related features. The WBD represents drainage areas of the country as eight nested levels of hydrologic units. The NHD and WBD are the most up-to-date and geographically inclusive hydrography datasets for the Nation.
The NHD and WBD are managed by the USGS under OMB Circular A-16 and as a part of the FGDC NGDA Inland Water Theme, with collaboration, support, and cost-sharing with many other federal, state, and local entities. This includes formalized Stewardship Agreements with partners to improve the NHD and WBD locally. Many tools exist to help with editing of the data, and user resources are also available.
NHDPlus High Resolution
The USGS is currently developing the NHDPlus High Resolution (NHDPlus HR). The NHDPlus HR is a nationwide, integrated hydrography and elevation geospatial dataset that includes the NHD stream network, WBD hydrologic units, local drainage areas or “catchments”, flow direction and flow accumulation rasters, and Value-Added Attributes (VAAs). The NHDPlus HR is built using the NHD at 1:24,000-scale or better, nationally complete WBD, and 1/3 arc-second seamless 3D Elevation Program (3DEP) data. Additionally, a new attribute, VisibilityFilter, is being calculated for the NHD and NHDPlus HR data, allowing stream network features in the NHD and NHDPlus HR to be displayed at eight approximate map scales. As of 2020, a “Beta” version of NHDPlus HR has been developed for approximately 80% of the Nation, including most of the conterminous U.S. and focused areas of Alaska. New NHDPlus HR datasets will be regenerated, or “refreshed”, to maintain integration with the NHD, WBD, and 3DEP data. Regular refreshes of NHDPlus HR are planned in the future to keep up with changes in the underlying datasets.
The USGS regularly collects corrections to the NHD, WBD, and NHDPlus HR datasets using a web-based Markup Application.
