Vector – Hydrography
Publications
USGS National Hydrographic Dataset (NHD)
The National Map National
Hydrography Dataset (NHD) Model (Feb 2006) 
PNW Hydrography Framework (PNWHF)
Pacific Northwest
Hydrography Framework Clearinghouse User Guide (Sept 2004)
Pacific
Northwest Hydrography Framework Clearinghouse Hydrography Data Dictionary (Sept
2004)
PNWHF/LLID
to NHD Migration Documentation 
Data
USGS National Hydrographic Dataset (NHD)
A comprehensive
hydrography. These data are flow
corrected, routed, and eventted. The
constituent set of point, line, and polygon data is linked together
relationally. See USGS NHD
publications above. Organized by level
4 HUs.
PNW Hydrography Framework (PNWHF)
A comprehensive hydrography. These data are flow corrected, routed, and
eventted. The constituent set of point,
line, and polygon data is linked together relationally.
The data model differs
from NHD, however, there is an ongoing effort to converge the technology and data
structure of the PNWHF data with that of the NHD. See the document PNWHF/LLID to NHD Migration Documentation
under PNW Hydrography Framework (PNWHF) publications above.
Hydrography data is
organized by level 4 HUs.
PNW Hydrography Framework Data
Level 6 (subwatershed)
and some level 7 (catchment) hydrologic units.
PNWHF 6th and 7th Level Hydrolgic Unit Boundaries
The U.S. Department of Agriculture, Natural Resources Conservation Service, should be acknowledged as the data source in products derived from these data.
Questions? Commemts?
Contact Keven Bennett kbenet@u.washington.edu