1. National Hydro Data Programs
National Elevation Dataset
(NED)
National Hydrography Dataset
(NHD)
NED-Hydrology
Watershed Boundary Dataset

2. Watersheds of the US 2-digit water resource regions
8-digit HUC watersheds

3. Hydrologic Unit Code Watersheds
~ 2000 for US, about the size of counties

4. Watershed Hierarchy Digit # 2 4 6 8 HUC 10 12 EDNA Available
In Progress

5. Watershed Boundary Dataset
National Program by USGS and USDA (NRCS)
Boundaries for 10- and 12- digit watersheds
First cut is by automated delineation from NED
Hand checked and edited
10-digit watersheds

6. EPA River Reach File 1 (RF1)

7. Source Water Protection
BASINS - Integrating GIS and Water Quality Modeling
Data
Cartographic
Monitoring
Loadings
Tools
Target
Assessment
Data Mining
Reporting
Models
HSPF - NPSM
QUAL2E
TOXIROUTE
Post-Processors
Target
Assess DM
Decisions
Watershed Management .
TMDL
Source Water Protection
Stormwater
State and Local Data

8. National Hydro Data Programs
National Elevation Dataset
(NED)
National Hydrography Dataset
(NHD)
NED-Hydrology
Watershed Boundary Dataset

9. National program by USGS and NWS
5000 cell threshold on a 30m DEM (~ 8 km2 average drainage area)
~ 1 million catchments for US when completed
Includes grid derived products e.g. topmodel index

10. River networks
for 8-digit HUC
watersheds

12. Lower West Fork, Trinity River Basin
HUC =

13. NHD River Reaches 412 River Reaches
In Upper West Fork of Trinity Basin

14. River Reach Codes Used for river address locations
ReachCode =
HUC#
Segment#
Location 0.392
on Reach

15. National Hydro Data Programs
National Elevation Dataset
(NED)
National Hydrography Dataset
(NHD)
NED-Hydrology
Watershed Boundary Dataset

16. National Elevation Dataset
Digital Elevation Model with 1 arc-second (30m) cells
Seamless in 1° blocks for the United States
10 billion data
Derived from USGS 1:24,000 quadrangle sheets

17. Digital Elevation Model (DEM)
720
720
Contours
740
720
700
680
740
720
700
680

18. Austin West 30 Meter DEM

19. Eight Direction Pour Point Model32 16 8 64 4
128 1 2
Water flows in the direction of steepest descent

20. Flow Direction Grid 32 16 8 64 4
128 1 2

21. Cell to Cell Grid Network
Through the Landscape
Stream cell

22. Delineation of Streams and Watersheds on a DEM

23. GTOPO30 - 1 km Digital Elevation Model of the Earth

24. Drainage in North America

25. 1500 Major Drainage Basins

28. County Level
Digital Soil Maps

29. National Land Cover Dataset

31. PRISM Mean Annual Precipitation

32. National Water Information System
Web access to USGS water resources data in real time

33. USGS National Water Information System.
Real-time and Historic Data
Streamflow and stage
Groundwater levels
Water Quality
Site information
Tabular or Graphical Format

34. USGS Water Watchp
Web access to USGS water resources data in real time