1. The National Hydrography Dataset Plus What is NHDPlus?

2. Vision for a National Geospatial Surface Water Framework
National Hydrography Dataset
(NHD)
National Elevation Dataset (NED)
Watershed Boundary Dataset (WBD)
How will this vision be attained?

3. The Team EPA Project Lead Tommy Dewald Horizon Systems Cindy McKay
Jen Hill
Bob Deffenbaugh
USGS WRD
Al Rea
Rich Moore
Craig Johnston
Modeling Consultant
Tim Bondelid

4. NHDPlus links the mapped stream network
An integrated suite of application-ready geospatial surface water data products.
It’s the first national effort to integrate:
National Hydrography Dataset (NHD)
National Elevation Dataset (NED)
National Watershed Boundary Dataset (WBD)
National Land Cover Dataset (NLCD)
NHDPlus links the mapped stream network
to the landscape.

5. NHD Plus – What’s Inside?
Greatly improved 1:100K National Hydrography Dataset
PLUS (9 more components):
Value Added Attributes
Elevation-based Catchments
Catchment Characteristics
Headwater Node Areas
Cumulative Drainage Area Characteristics
Flow Direction, Flow Accumulation, and Elevation Grids
Min/Max Elevations and Slopes
Flow Volume & Velocity Estimates
Flow Gages with Network Locations
NHDPlus evolved from an EPA project intended to produce flow volume and velocity estimates for the stream network in 1:100K NHD.
Along the way, we produced a set of very useful components. Obviously the first is (CLICK)
READ

6. What is the National Hydrography Dataset (NHD)?
A Framework dataset that includes:
Hydrographic features for making maps
A national stream addressing system
A modeling network for navigating upstream/downstream
A maintenance infrastructure
User updates
Distributed formats – personal geodatabase, shapefiles, coverages
Compatible with ArcHydro Model & Tools
As the name implies NHDPlus begins with the NHD.
Courses on NHD can last the better part of a week. Here is NHD in a single slide.
First of all it’s a Framework dataset – that’s framework with a capital F – because the Federal Geographic Data Committee has designated NHD as national framework layer for hydrography.
NHD consists of a set of approximately 50 hydrographic feature types that can be used to make maps.
NHD contains a national stream addressing system that enables you to tie points (CLICK) such as
drinking water intakes or monitoring stations to positions along the NHD stream network.
Or you can tie information such as locations of impairments (CLICK) to stretches along the a stream.
The stream network provides a modeling network on which you can navigate upstream and downstream.
Possibly one of NHD’s most important characteristics is that it has a maintenance infrastructure that allows and even encourages user updates. All the NHD predecessors (the EPA River Reach Files and the USGS Digital Line Graph datasets) either did not support any updating or didn’t support updates from the user community.
NHD is distributed in a variety of formats including pgdb and shapefiles.
Finally, NHD is compatible with the ArcHydro data model and the ArcHydro tool set. 3 1 2
Impairment
Drinking
Water
Intake

7. Value-Added Attributes
(Stream Order, Stream Level, Waterbody-Network link and more…)
A set of two dozen network characteristics
Derived from native NHD content
For Analysis, Navigation & Display

8. Elevation Grid (elev_cm)
National Elevation Data (NED) used to create the NHDPlus

9. Hydrologically-Conditioned Elevation
National
Hydrography
Dataset (NHD)
Watershed
Boundary
Dataset (WBD)
The first elevation processing step was to hydrologically condition the elevation values.
This means that we made the (CLICK) elevation data agree with the (CLICK) watershed boundary dataset and (CLICK)
with the NHD dataset.
National
Elevation
Dataset (NED)

10. Flow Direction Grid (FDR)
Cells point down hill
to the neighboring cell
with the lowest elevation
Flow Accumulation Grid (FAC) 5
Cells contains the count of the number of cells that are uphill

11. Catchment Grid & Shapefile
The portion of the land surface that drains to a network flowline

12. Catchment Attributes Mean Annual Temperature (Prism - 4km)
Mean Annual Precipitation (Prism - 4km)
% of each of the 21 land use classifications from the 1992 National Land Cover Dataset (NLCD)

13. Flowline Attributes Raw min/max elevations Smoothed min/max elevations
Slope
Cumulative drainage area
Cumulative land use classifications
Flow volume, incremental inflow – Unit Runoff Method
Flow volume – Vogel Method
Velocity – Jobsen

14. USGS Gage Point Events on NHDPlus – Coming Soon!
Many Attributes:
Gage ID
Reachcode/Measure
Lat/Long
Agency
Station Name
Several Dozen Flow Stats
And more…
We built this file as part of the NHDPlus project.
Blind snap to NHD network.
QAQC by WRD District Offices
Conversion of qaqc’ed locations to reachcodes/measures
Distributed as a shapefile.
This was not a totally altruistic exercise. We needed these gages to qaqc our drainage areas and flow volume and velocity.
So this is a perfect time to take a break and when we come back Tim will talk about remaining parts of NHDPlus.
Before we break, we have a few minutes for questions – does anyone have questions?

15. Distribution Units for Elevation, FAC, and FDR Grids
62 units total

16. NHDPlus Distribution Units for NHD, Catchments, and Attribute Tables09 17
10U 01 04 02 07 16
10L 14 05 18 11 06 15 13 08 03
0318 20 12 10 06 01 02 03 04 09 11 07 05 12 13 14 16 17 18 20
0318 08 15

17. Linking Data to the NHDPlus
Linear Reach:
Measure:
Point Links
Linear Links
Linear Reach:
From Measure: 15.0
To Measure:
Area Links
Waterbody Reach:
shape

18. Things Linked to NHDPlus
EPA Water Programs
Water Quality Standards
Water Quality Monitoring Stations
Assessed Waters
Impaired Waters
Nonpoint Source Projects
Beaches
Fish Consumption Advisories
Sewage No Discharge Zones
Permitted Dischargers
Drinking Water Intakes
Drinking Water Wells
Clean Watershed Needs
Special Appropriations Projects
And More…
USGS Flow Gages
Rather than creating events, you may chose to use the many, many events that have been tied to NHD by various federal and state agencies. For example, here is the list of events available from EPA.
Many EPA Water Programs have been linked to NHD. (CLICK) This is the current list but it’s constantly growing.
(CLICK)Some of the event tables are downloadable from the EPA website.

22. A Quick Example of Analysis Using NHDPlus

23. STEP 1
Knowing this is all well and good, except the discharge points on an impaired water are not the only discharge points that we need to be concerned about. The ones upstream of an impaired water may also be important to our analysis. So lets pick an impaired water and use our VAA navigation tool to click on the downstream end of the impairment and (CLICK)

24. STEP 2

25. STEP 3

26. STEP 4

27. STEP 5

28. STEP 6

29. STEP 7

30. STEP 8 Value Added Attributes Temperature & Precipitation Flow Volume
Velocity
Land
Use

31. Watershed Characterization
Main Stem: Huntsville Spring Branch
Stream Order: 3
Stream Level: 4
Area weighted precipitation mm
Area weighted temperature oC
Land Use
Open Water 1%
Residential 28%
Commercial/Ind/Trans 9%
Barren %
Forest %
Pasture/Hay %
Row Crops 12%
Urban/Rec Grasses 5%
Wetlands 5%
Other 1%
Drainage area km2
Mean Annual Flow (UROM) cfs
Mean Annual Flow (Vogel) cfs
Mean Annual Velocity (UROM) 0.95 fps
Mean Annual Velocity (Vogel) fps
So we know that – READ
We’ve done all this with just the native NHDPlus content.

32. Importance of the NHDPlus
The NHDPlus Is a Complete Analytical Tool
Very Robust Stream Network
New Attributes for Improved Applications
Catchments, FDR, FAC and Elevation Add the Landscape into the Analytic Environment
Watershed Delineation and Characterization
Integration with virtually any landscape dataset
Models!!!!

33. NHDPlus – What’s Available?
Data:
Great Lakes (04)
Mississippi (05, 06, 07, 08, 10, 11 and 0318)
Texas (12)
Rio Grande (13)
Colorado (14 and 15)
Great Basin (16)
Pacific Northwest (17)
California (18)
New England (01)
Mid-Atlantic (02)
By End of September – South Atlantic (03), Souris-Red-Rainy (09)
Documentation:
User Guide
Various Presentations
Metadata
Release Notes for each hydro region
Training:
Eight Exercises/Tutorials
Tools:
NHD Flow Table Navigator
NHDPlus VAA Navigator
#0 – Preparation
#1 – Setting Up The Data
#2 – Linking Data to NHD
#3 – Navigating with Geometry
#4 – Navigating with VAAs & Flow Table
#5 – Network Analysis
#6 – Raster Dataset
#7 – Watershed Delineation
#8 – Simple Model

34. Where to get NHDPlus Data, Documentation, Presentations, Exercises and Tools
Web Site: Click on “NHDPlus”
Web Site:
FTP Site: ftp://ftp.horizon-systems.com/nhdplus
Fall 2006: In the EPA Waters Database