NHDPlus (National Hydrography Dataset Plus)
We encourage first-time users to familiarize themselves with the following sections of the NHDPlusV2 User Guide (under "Documentation" below), before starting to work with NHDPlus data.
• Introduction to NHDPlus
• NHDPlusV2 Data Structure
• A Guide for Installing NHDPlusV2 Data
• NHDPlusV2 Distribution Files and NHDPlusV2 Components
• Understanding and Using NHDPlusV2
On this page:
- Data Extensions
- User Applications
- Data Stewardship
- News and Events
- NHDPlus Version 1 (NHDPlusV1)
- Keeping In Touch
- NHDPlusV2 User Guide
- NHDPlusV2 Metadata
- NHDPlusV2 Technical Documents
- NHDPlusV2 Training
- NHDPlusV2 Conference Presentations
- NHDPlus Story
- NHDPlus Versioning
- NHDPlus Flyer
Download NHDPlus Version 2 metadata and Extended Metadata components from the links below:
- NHDPlusV2 Metadata (HTM) (XML)
- NHDPlusV2 GageLoc Metadata (HTM)
- National Hydrography Dataset Metadata (ZIP)
- National Watershed Boundary Dataset Metadata (ZIP)
- National Elevation Dataset, August 2010 Metadata (ZIP)
- National Elevation Dataset, February 2011 Metadata (ZIP)
- National Elevation Dataset, June 2011 Metadata (ZIP)
- National Elevation Dataset, August 2011 Metadata (ZIP)
- National Elevation Dataset, December 2011 Metadata (ZIP)
- National Elevation Dataset, Hawaii, January 28, 2014 Metadata (ZIP)
- National Elevation Dataset, Puerto Rico, January 28, 2014 Metadata (ZIP)
- National Elevation Dataset, Guam, February 19, 2014 Metadata (ZIP)
- National Elevation Dataset, Northern Mariana, January 28, 2014 Metadata (ZIP)
- National Elevation Dataset, American Samoa, February 10, 2014 Metadata (ZIP)
- National Elevation Dataset Data Dictionary, August 2010 (ZIP)
- Canadian Digital Elevation Data Metadata (ZIP)
- Canadian Digital Elevation Data Index Polygons (ZIP)
NHDPlusV2 Technical Documents
- EROM Mean Monthly Flows (PDF)
- USGS Standards for the National Hydrography Dataset (1:100,000-scale) (PDF)
- NHD Concepts and Contents (PDF)
The NHDPlusV2 Training Series is intended to help NHDPlus users gain an understanding of the contents of NHDPlus components, including the files and fields that may be useful in their NHDPlus applications. The Training Series employs a combination of lecture-style slide presentations and associated hands-on, do-it-yourself exercises. In addition to the core Training Series presentations and exercises, you’ll also find below videos of the presentations and hands-on exercises from the NHDPlus Workshop (July, 2016 – Sacramento, CA).
New NHDPlus users are encouraged to complete the following prerequisite task before viewing the presentations and attempting the full set of exercises:
- Read the following sections of the NHDPlusV2 User Guide
- Introduction to NHDPlus
- NHDPlusV2 Data Structure
- A Guide for Installing NHDPlusV2 Data
- NHDPlusV2 Distribution Files and NHDPlusV2 Components
- Understanding and Using NHDPlusV2
Training Presentations (slides with Notes)
The Training Series presentations include slides with detailed descriptions in their Notes section.
- Introduction to NHDPlusV2 (PPTX)
The presentation provides a basic understanding of NHDPlus, including basic NHDPlus concepts, data content, and core tools. It also presents some examples of how NHDPlus is being applied.
- NHDPlusV2 Content (PPTX)
The presentation covers the source datasets from which NHDPlusV2 is build and data components found within NHDPlusV2.
- NHDPlusV2 Processing and Distribution Units (PPTX)
The presentation helps users understand how NHDPlusV2 data is organized and distributed by major Drainage Areas that consists of Vector Processing Units (VPU) and Raster Processing Units (RPU). It also explores the contents of the NHDPlus BoundaryUnit shapefile and how it can be used to explore the spatial distribution of these units.
- NHDPlusV2 Data Model (PPTX)
The presentation describes the NHDPlusV2 data model, how table keys link NHDPlus components together, and how to perform appropriate joins and relates between NHDPlus components.
- NHDPlusV2 Network Value Attributes - Part 1 (PPTX)
The presentation covers fundamentals of the value added attributes (VAA), discusses the NHDFlowline attributes and navigation attributes, and describes the NHDPlusV2 VAA Navigator Tool.
- NHDPlusV2 Network Value Attributes - Part 2 (PPTX)
The presentation builds on Part 1 by focusing on the VAAs that are designed for various types of network analysis: Stream Order, Stream Calculator, Level Path Identifier, Terminal Path Identifier, Up Level Path Identifier, Down Level Path Identifier, Path Length, Arbolate Sum, and Return Divergence.
- NHDPlusV2 Network Value Attributes - Part 3 (PPTX)
The presentation builds on Part 2 by focusing on additional VAAs that are designed for various types of network analysis: Divergences, Drainage Area, Flow, Elevations and Slopes.
- NHDPlusV2 Network Value Attributes - Part 4 (PPTX)
The presentation builds on Part 3 by describing the format and content of the PlusFlow table and the mechanics of using the table to traverse the NHDPlus network. It also describes how to obtain, install, and use the Flow Table Navigator Tool.
- NHDPlusV2 Raster Components (PPTX)
The presentation covers the rasters that are included in the NHDPlusV2 data suite, how these components are used to develop catchments, and other possible uses of the raster components.
- NHDPlusV2 Burn Components (PPTX)
The presentation describes the use of NHDPlus Burn Components as feature level metadata for the hydro-enforcement and catchment delineation process. It highlights limitations of the BurnLineEvent.
- NHDPlusV2 Extensions (PPTX)
The presentation describes the computation of flow and velocity estimates, as well as some uses of the supporting data developed for computing flows.
- NHDPlusV2 National and Global Data (PPTX)
The presentation describes the development and potential uses of the NHDPlusNationalData (USGS Streamflow Gages, Watershed Boundary Dataset (WBD) Snapshot, and NationalCat Grid) and NHDPlusGlobalData (BoundaryUnit and Supercatchments).
- NHDPlusV2 Data Curiosities and Anomalies (PPTX)
The presentation provides examples of data curiosities and anomalies that NHDPlus users may encounter. It discusses artifacts that exist in the source ingredient datasets and introduced during the raster creation process.
- NHDPlusV2 Basin Delineation (PPTX)
The presentation helps users understand basin delineation, learn various ways to delineate basins using NHDPlusV2 and learn how to use the NHDPlusV2 Basin Delineation Tool.
Training Exercises (hands-on, do-it-yourself style)
Use the links below to obtain the data necessary for performing the exercises.
- Exercise 0 - Installing Tools and Data (PDF)
This exercise is a prerequisite for all other exercises. It provides instructions for acquiring the data and the tools needed to complete the other exercises.
- Exercise 1 - Setting Up the Data (PDF)
In this exercise, you'll learn: (1) how to obtain and install NHDPlusV2 data; (2) how to use a special NHDPlusV2 tool to quickly build indexes and pyramids; and (3) an easy method for keeping your NHDPlusV2 data up to date.
- Exercise 2 - Linking Data to NHD (PDF)
In this exercise, you'll learn how to use the NHD linear referencing system to link data to the NHD stream network in NHDPlusV2.
- Exercise 3 - Navigating With Geometry (PDF)
In this exercise, you'll learn how to navigate the NHD stream network using the geometry of the stream network features.
- Exercise 4 - Navigating with the Flow Table and With VAAs (PDF)
In this exercise, you'll learn how to navigate the NHD stream network using the NHDPlusV2 flow table and using the NHDPlusV2 VAAs with tools built specifically for that purpose.
- Exercise 5 - Network Analysis (PDF)
This exercise combines what you learned in exercises 2, 3, and 4 to illustrate network analysis using NHDPlusV2.
- Exercise 6 - Raster Datasets (PDF)
NHDPlusV2 contains many raster datasets. In this exercise, you'll learn how best to use raster data and how to symbolize NHDPlusV2 raster data in a map.
- Exercise 7 - Watershed Delineation (PDF)
In this exercise, you'll learn how to delineate a watershed (the drainage area upstream) from a point along the stream network.
- Exercise 8 - NHDPlusV2 Simple Model (PDF)
This exercise provides a simple dilution model as an example of how NHDPlusV2 can be used to build models.
Workshop Presentations (videos of lecture-style slide presentations)
These videos cover the same topics described by the slides with Notes above, as well as several additional topics, that were recorded during the NHDPlus Workshop co-sponsored by the California Water and Environmental Modeling Forum and the California Department of Water Resources (July 2016, Sacramento, CA).
These close-captioned videos are available as a playlist on the California Department of Water Resources YouTube channel at https://www.youtube.com/playlist?list=PLeod6x87Tu6eFDeG9DSng7O36ynsm6w3w
To turn Closed Captioning on (or off), click on the “CC” button on the video control panel that pops up when you place your cursor on the bottom of the video window.
The titles and duration times (mm:ss) for the individual videos on the playlist are:
- Intro (12:30)
- Content (19:19)
- Processing and Distribution Units (17:51)
- Data Model (11:50)
- Linking Data (27:18)
- NHDPlus Attributes Part 1 (36:25)
- NHDPlus Attributes Part 2 (15:11)
- NHDPlus Attributes Part 3 (23:35)
- NHDPlus Attributes Part 4 (12:57)
- Raster Components (23:46)
- Extensions - including Stream Flow Estimates, Catchment Allocations and Accumulations (34:48)
- Data Curiosities and Anomalies (27:31)
- Basin Delineation (18:13)
- Future of NHDPlus (13:46)
Workshop Exercise (hands-on, do-it-yourself style)
This Workshop Exercise is a single, fully-integrated exercise whose sections build upon each other from first to last. It covers many of the same topics (plus several more) that are described in the Exercises section above and uses different data.
Workshop Exercise Components
Use the links below to obtain the data and other components necessary for performing the exercise.
- Workshop Exercise Download1 (ZIP)
- Workshop Exercise Download2 (ZIP)
- Workshop Exercise Download3 (ZIP)
- Workshop Exercise Download4 (ZIP)
- Workshop Exercise Download5 (ZIP)
- Workshop Exercise Download6 (ZIP)
Workshop Exercise Guide
2016 AWRA GIS Conference Presentations – July 2016
- EPA WATERS - Network Linked Data and Applications - Dewald (PPTX)
- NHDPlus and the National Water Model - Maidment (PDF)
- ICWATER (Spill Response) - Samuels (PPTX)
- The Stream-Catchment Dataset (StreamCat) - Hill (PDF)
2015 ESRI User Conference Presentations - July 2015
- NHDPlus - the Evolution of a Surface Water Geofabric – Dewald (PPTX)
- NHDPlus Activities in Support of the Open Water Data Initiative – Rea (PPTX)
2014 AWRA GIS Conference Presentations - May 2014
- Catching Up on NHDPlus - Dewald (PPTX)
- EPA's GeoPilot - Young (PPTX)
- EROM - NHDPlusV2 Flow Estimation - Bondelid (PPTX)
- Building Analytical Applications Using NHDPlusV2 - McKay (PPTX)
USGS EGIS Presentations - February 2014
2013 ESRI User Conference Presentations - July 2013
- An Update on NHDPlus - Dewald, McKay (PPTX)
- NHDPlus Version 2 Web Services - Rea, Dewald, McKay (PPTX)
2012 ESRI User Conference Presentations - July 2012
- NHDPlus Concepts, Applications, and Plans - Tommy Dewald (PPTX)
- NHDPlusV2 Introduction & Status - Cindy McKay (PPTX)
- NHDPlusV2 DEM Derivatives - Al Rea (PPTX)
- NHDPlusV2 EROM Flow Estimation - Tim Bondelid (PPTX)
- NHDPlus Sparrow Modeling - Rich Moore (presented by Al Rea) (PPTX)
- History of the USEPA River Reach Files (PDF)
- Weaving the National Hydrologic Geospatial Fabric (PDF)
- Making the Digital Water Flow (PDF)
- NHDPlusV2 Flow Table Navigator Toolbar
- NHDPlusV2 Toolbox
- NHDPlusV2 VAA Navigator Toolbar
- NHDPlusV2 Catchment Attribute Allocation and Accumulation Tool (CA3TV2)
- NHDPlusV2 BasinDelineator Tool
- NHDPlusV2 Web Services and Tools
- Hydrography Event Management Tool
NHDPlusV2 Flow Table Navigator Toolbar
The Flow Table Navigator uses the NHDPlusV2.1 PlusFlow table to walk the network from one network feature to the next. The navigator performs four types of navigation: upstream main stem, upstream with tributaries, downstream main stem, and downstream with divergences. The navigator may be used via this special ArcMap Toolbar. The navigator works on any NHDPlusV2.1 Vector Processing Unit (VPU). Results are returned to ArcMap as a selected set in the NHDFlowline layer. Use of the flow table navigation tools are demonstrated in training Exercise #4 found in the above "Documentation" dropdown.
System Requirements: Windows 7; ArcGIS 10.1/SP 1
The NHDPlusV2 Toolbox contains geoprocessing tools specifically for use with NHDPlusV2.1 data. The toolbox currently contains two tools: Prep NHDPlusV2.1 Data and Check NHDPlusV2.1 Currentness. Installation of the toolbox is described in training Exercise #0 found in the above "Documentation" dropdown.
The Prep NHDPlusV2.1 Data tool processes the user's local NHDPlusV2.1 data holdings and creates spatial indexes, attribute indexes, and grid pyramids. Indexes and pyramids help ArcGIS process and display NHDPlusV2.1 data faster. Use of the tool is demonstrated in training Exercise #1 found in the above "Documentation" dropdown.
The Check NHDPlusV2.1 Currentness tool compares a user's NHDPlusV2.1 data holdings against the data contained on the NHDPlus website and reports differences in individual data component versions. NHDPlusV2.1 data components are updated from time to time, if errors are discovered. This tool helps users determine whether any data in their local collection has an update available. Use of the tool is demonstrated in training Exercise #1 found in the above "Documentation" dropdown.
System Requirements: Windows 7; ArcGIS 10.1/SP 1
- NHDPlusV2 Toolbox (ZIP)(34 K)
NHDPlusV2 VAA Navigator Toolbar
The NHDPlusV2 VAA Navigator uses the NHDPlusV2.1 Network Value Added Attributes to provide network navigation with a number of user options. The navigator performs four types of navigations: upstream main stem, upstream with tributaries, downstream main stem, and downstream with divergences. The navigator may be used in ArcMap via the VAA Navigator Toolbar or called from user-written program code.
When used in ArcMap, the navigator will navigate any NHDPlusV2.1 Vector Processing Unit (VPU). When called from user-written program code, it is possible to navigate a multi-VPU drainage area like the Mississippi or the Colorado. The Navigator provides navigation stop distances and filtering of navigation results based on several NHDPlusV2 attributes. Navigations can be done with whole NHDFlowline features or from point-to-point along the network.
- NHDPlusV2 VAA Navigator Install (PDF)(4 pp, 275 K)
- NHDPlusV2 VAA Navigator User Guide (PDF)(15 pp, 774 K)
System Requirements: Windows 7 Service Pack 1 64-bit; ArcGIS 10.1 Service Pack 1; Microsoft .NET Framework 4.0.3 or higher; Microsoft SQL Server 2012 Express LocalDB 64-bit
The primary testing environment has been ArcGIS 10.1 Service Pack 1; Windows 7 64-bit Service Pack 1; Microsoft .NET Framework 4.5. Superficial testing has been done in ArcGIS 10.2.2 and thus far no problems have been found. No testing has been performed on Windows 32-bit operating systems.
Installation Order: Microsoft .NET, Microsoft SQL Server 2012 Express LocalDB, then NHDPlusV2 VAA Navigator Toolbar Install (ZIP)(654 K)
NHDPlusV2 Catchment Attribute Allocation and Accumulation Tool (CA3TV2)
CA3TV2 has two main functions, an attribute allocation function and an attribute accumulation function, which may be used separately or in combination. The CA3TV2 allocation function takes a user-supplied raster dataset of landscape attributes and allocates the attributes to the NHDPlusV2 catchments. For each NHDPlusV2 NHDFlowline network feature (i.e. the subset of NHDFlowline features with NHDFlowline.Flowdir = "With Digitized"), the CA3TV2 accumulation function builds the upstream accumulated values for attributes that have been allocated to either NHDPlusV2 catchments or NHDPlusV2 NHDFlowline features.
Instructions for using CA3TV2 are integrated into the tool and accessed from the "Help" function on the startup window.
ATTENTION: Important instructions are contained in the Readme file. Due to a change from ArcGIS 10.1 to 10.2.2, a Windows setting must be changed in order for CA3TV2 to operate correctly.
- NHDPlusV2 CA3TV2 Readme (PDF)(3 pp, 57 K)
System Requirements: Windows 7 Service Pack 1 64-bit; ArcGIS 10.2.2 and Spatial Analyst Extension; Microsoft .NET Framework 4.0.3 or higher; Microsoft SQL Server 2012 Express LocalDB 64-bit
Installation Order: Microsoft .NET, Microsoft SQL Server 2012 Express LocalDB, then NHDPlusV2 CA3TV2 Install (ZIP)(1.8 MB)
The CA3TV2 accumulation function requires one NHDPlusV2.1 Data Extension and the most recent version of the NHDPlusV2.1 Global Data:
NHDPlusV2 BasinDelineator Tool
BasinDelineator delineates drainage basins for a user-defined set of basin pourpoints on the NHDPlusV2 network. The input pourpoints may be specified using one of two methods. In the first method, the user specifies a basin identifier, an NHDFlowline reachcode, and a measure along the reach. In the second method, the user specifies a basin identifier and the latitude/longitude coordinates of the pourpoint.
The pourpoints must be located on the NHDPlusV2 NHDFlowline network which is defined as the subset of NHDFlowline features with known flow direction (i.e. NHDFlowline.Flowdir = "With Digitized"). BasinDelineator returns a shapefile which contains a basin polygon for each correctly specified basin pourpoint. Instructions for using BasinDelineator are integrated into the tool and accessed from the "Help" function on the startup window.
- NHDPlusV2 BasinDelineator Readme (PDF)(2 pp, 40 K)
There are two versions of the BasinDelineator Tool:
- NHDPlusV2 Basin Delineator Install for Windows 7, ArcGIS 10.5.1 (ZIP)(21.0 MB)
- NHDPlusV2 Basin Delineator install for Windows 10, ArcGIS 10.6.1 (ZIP)(21.0 MB)
System Requirements: Appropriate version of Windows and ArcGIS. ArcGIS Spatial Analyst Extension; Microsoft .NET Framework 4.6.1 or higher; Microsoft SQL Server 2012 Express LocalDB 64-bit
Installation Order: Microsoft .NET, Microsoft SQL Server 2012 Express LocalDB, then NHDPlusV2 BasinDelineator Install.
The BasinDelineator requires one NHDPlusV2.1 data extension and the most recent version of the NHDPlusV2.1 Global Data:
NHDPlusV2 Web Services and Tools
In addition to the core NHDPlus desktop tools described above, the EPA Office of Water has developed an extensive collection of core NHDPlus-based Web applications, services and tools that leverage their WATERS data architecture. The Watershed Assessment, Tracking and Environmental Results System (WATERS) is a geospatial data architecture that integrates many of the EPA Office of Water’s major data systems through their linkages to the NHDPlus stream network.
Hydrography Event Management Tool
The Hydrography Event Management (HEM) Tool provides functionality for adding and editing events on the NHD. In GIS nomenclature, ‘events’ are hydrologically-linked data that are referenced to the NHD using a linear referencing system implemented along NHDFlowlines. The HEM tool handles all the linear referencing mechanics to make working with events easy. HEM can make events on the point, flowline, and waterbody features in the NHD. HEM allows events to be located interactively, imported, or calculated. An editable “Source Feature ID” field provides the link between the event location and the informational data tied to the location. HEM also provides powerful feature-level metadata editing tools. Finally, HEM has the ability to measuring distances from a point through the NHDFlowline network.
The HEM was developed by the Bureau of Land Management and is now supported by the USGS for the larger NHD user community. Complete user documentation, system requirements and installation instructions are provided on the HEM web site.
The NHDPlus data model is composed of "core" and "extended" components. Core components are the direct result of integrating the NHD network, NED topography and WBD boundaries. Extended components are derived from or associated with core components. For example, streams and catchments are core components, while catchment attributes, flow estimates and simplified catchments are extended components. We expect that additional data extensions will be developed by the NHDPlus team and user community over time.
Note that the EROM, Vogel, VPUAttribute, and NHDPlusAttribute data extensions can be downloaded from the Get Data tab. All data extensions unzip into the standard Vector Processing Unit (VPU) folders.
- NHDPlusV2.1 Accumulation Extension
These data are pre-computed spatial indexes used by the desktop Catchment Attribute Allocation and Accumulation Tool (CA3T). The CA3TV2 accumulation function requires this Data Extension and the most recent version of the NHDPlusV2.1 Global Data.
- NHDPlusV2.1 Simplified Catchment Extension
Simplified catchments are produced from original detailed NHDPlus catchments by thinning vertices for purposes of improving display (draw) times in Web mapping applications and to improve performance for analysis of larger areas.
- NHDPlusV2.1 NLCD 2011 Extension
National Land Cover Dataset (NLCD) landscape attributes that have been allocated and accumulated for original NHDPlus catchments using the CA3T desktop tool.
View our catalog of NHDPlus user applications.
We encourage and welcome you to provide information describing your NHDPlus applications so others can learn about them. With this thought in mind and with your assistance, we’ve compiled a catalog of NHDPlus applications.
If you haven’t done so already, please submit your own NHDPlus work for inclusion in the catalog.
Minimally, we need an application title, organization (name, city, state), contact name and email to post your work on the applications page. It would be better yet, if you can provide additional information describing your application in the form of a web page link or a fact sheet.
If you have an existing fact sheet that you’d like to provide please consider including the recommended information listed below, then pass it along through email using the Contact Us link at the bottom of the page. We’ll add the title of the fact sheet and the contact name and organization sponsoring the project to the applications catalog accessible from this page.
- Project Title:
- Project Background:
- Project Description:
- Technologies employed
- Related Web sites
- Outcome or Benefits:
- The role of NHDPlus in this result
- The relationship to organization’s strategic plans/goals, as appropriate
- For more information, contact:
- Organization including city and state
- Phone number
Data Stewardship for Medium Resolution NHD and NHDPlus
The EPA Office of Water has played a collaborative role in the development and maintenance of NHD, WBD and NHDPlus, since it first approached the USGS National Geospatial Program (NGP) in the mid-1990s about developing the medium resolution (1:100,000-scale) NHD. In the early 2000s, when the USGS NGP, USFS and state cooperators initiated the production of the high resolution NHD (1:24,000-scale or better), EPA assumed the role of primary custodian for the medium resolution NHD to support their ongoing programs and those of the users. The medium resolution NHD provides the hydrologic foundation for the medium resolution NHDPlus that was first produced in partnership with the USGS Water Program in 2006.
NHDPlus is a suite of geospatial products that are derived from static snapshots of the National Hydrography Dataset (NHD) stream network (1:100,000-scale), Watershed Boundary Dataset (WBD) hydrologic units (12-digit), and National Elevation Dataset (NED) topography (30m) through a sophisticated data integration process. The derived components of NHDPlus are updated using the latest versions of the NHD, WBD and NED on a periodic basis, as determined by programmatic priorities and resources. For example, the production of NHDPlus Version 2 was largely driven by USGS Water Program requirements for improved regional water quality modeling capabilities. USGS Water and the EPA Office of Water worked together to update the NHD in preparation for NHDPlus Version 2 and, also, shared the cost for producing it.
The medium resolution NHD used to produce NHDPlus is available for download on this web site under the Get Data/Tools tab for all regions shown on the selection map. The NHDSnapshot file found on each regional page is in Shapefile format and the NHDSnapshotFGDB file is in File GeoDatabase format, which can be used with the USGS Hydrography Event Management (HEM) tool to facilitate linking data to the NHD. Documentation for the medium resolution NHD can be found on under the Learn More tab >> User Guide link and Technical Documents link, where the Map Standards NHD (1:100,000-scale) and the NHD Concepts and Contents documents are available.
Reporting Updates to Medium Resolution NHD in NHDPlus
Our experience shows that due to the complexity of the NHD it is most effective to have users identify and report errors that can then be corrected by EPA data editors. This is a similar approach successfully applied by the USGS NGP for their series of national NHD maintenance lite revisions, by the USGS Water Program, and, also, by the multi-state, multi-organization Pacific Northwest hydro consortium.
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. This information should be emailed to NHDPlus Support (firstname.lastname@example.org).
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!
April 17-19, 2018
EPA GIS Workshop
Research Triangle Park, NC
Includes discussions of NHDPlus data, tools and applications.
April 22-25, 2018
AWRA Specialty Conference on Water Resources and GIS
Numerous sessions on NHDPlus capabilities and water quality applications.
July 9-13, 2018
ESRI User Conference
San Diego, CA
Presentations on NHDPlus as part of Water Resources Track.
NHDPlusV2 supercedes (replaces in its entirety) NHDPlusV1. NHDPlusV1 data, metadata and documentation will remain available through this site for the foreseeable future; however, users are encouraged to migrate existing applications and develop new applications using the significantly improved NHDPlusV2.
Released in 2006, the NHDPlusV1 consists of ten components:
- Snapshot of the 1:100K National Hydrography Dataset (NHD)
- Snapshot of the 30 meter National Elevation Dataset (NED)
- Watershed Boundary Dataset (WBD) data for 12 states
- 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 and flow accumulation grids
- Flowline min/max elevations and slopes
- Flow volume & velocity estimates for each flowline in the stream network
NHDPlusV1 data was developed by hydrologic region within the U.S., except hydrologic region 10 which is divided into 10 Upper (10U) and 10 Lower (10L). The NHDPlusV1 Elevation, Flow Accumulation and Flow Direction grids are distributed by sub-parts of hydrologic regions that are called "production units". A national shapefile of the production units (ZIP)(3.7 MB) is available.
NHDPlusV1 data may be downloaded using the following:
- NHDPlusV1 Data Download
- Metadata (XML)(18 K), Metadata (PDF)(11 pp, 41 K)
- Data Extensions
If you would like to receive periodic emails about the availability of NHDPlus data, tools and updates, please send your name, phone number, organization, and email address to NHDPlus Support (email@example.com).