NHDPlusV2 consists of the following components:
- Greatly improved 1:100K National Hydrography Dataset (NHD)
- Greatly improved 1 arc-second (approximately 30 meter ground spacing) National Elevation Dataset (NED)
- Nationally complete Watershed Boundary Dataset (WBD)
- A set of value added attributes to enhance stream network navigation, analysis and display
- An elevation-based catchment for each flowline in the stream network
- Catchment characteristics
- Headwater node areas
- Cumulative drainage area characteristics
- Flow direction, flow accumulation and elevation grids
- Flowline min/max elevations and slopes
- Flow volume & velocity estimates for each flowline in the stream network
- Catchment attributes and network accumulated attributes
- Various grids from the hydro-enforcement process including the hydro-enforced DEM.
NHDPlusV2 attribute and vector data are distributed by hydrologic regions (HUC2) or, in the case
of regions 10 and 03, parts of hydrologic regions. These regions or parts of regions are
called Vector Processing Units (VPUs). The NHDPlusV2 raster components are distributed by sub-parts
of VPUs called Raster Processing Units (RPUs).
The NHDPlusV2 User Guide is available here.
Important information is also contained in the release notes that are posted with each VPU.
A national shapefile of the VPU and RPU boundaries is available here.
All available data is served from the Horizon Systems FTP site and may be freely downloaded.
Reporting Errors in NHDPlus
If you discover an error in the NHDPlus stream network or waterbodies, please report it by emailing Horizon NHDPlus Support.
Depending on the type and extent of the error, it may be corrected immediately or placed in an update queue awaiting a refreshed version of NHDPlus.
When reporting errors, please provide a geographic reference to the features that need to be corrected; VPUid + comid is best. If the error is in NHDPlus attribution, like a feature (GNIS) name, then also describing the correction would be helpful. If the error is in geometry, then please provide a screen capture (containing comids) of the NHDSnapshot feature(s) in error overlaid on an image (from some reputable source) of how the geometry should look and a description of the edits that need to be made.
Please also supply a contact person who is able to answer questions, if we have any, when we are actually doing the editing.
Thank you for your interest in NHDPlus and taking the time to help make it better!