HUC12: USGS Watershed Boundary Dataset of Subwatersheds (USGS/WBD/2017/HUC12)

The Watershed Boundary Dataset (WBD) is a comprehensive
aggregated collection of hydrologic unit (HU) data consistent
with the national criteria for delineation and resolution. It
defines the areal extent of surface water drainage to a point
except in coastal or lake front areas where there could be multiple
outlets as stated by the Federal Standards and Procedures for
the National Watershed Boundary Dataset
Watershed boundaries are determined solely upon science-based
hydrologic principles, not favoring any administrative boundaries
or special projects, nor particular program or agency. The intent
of defining HUs for the WBD is to establish a baseline drainage
boundary framework, accounting for all land and surface areas.

The HUs are delineated at 1:24,000-scale in the conterminous
United States, 1:25,000-scale in Hawaii and the Caribbean, and
1:63,360-scale in Alaska, meeting the National Map Accuracy Standards
(NMAS). WBDs are represented as polygons that define the boundary
of the HUs. The HUs are given a Hydrologic Unit Code (HUC) that
ranges from 2 digits to 12 digits. These codes describe where
the unit is in the country and the level of the unit. The number
of digits in a HUC is related to 6 levels of detail for the WBD:
the lower level polygons cover larger areas than higher level
ones. The higher the level, the more digits to the HUC, since
previous levels are nested in it.

The WBD polygons attributes
include HUCs, size (in the form of acres and square kilometers),
name, downstream HUC, type of watershed, non-contributing areas,
and flow modifications. WBD line attributes contain the highest
level of hydrologic unit for each boundary, line source information
and flow modifications.

| Name | Level | Digit | HU Code |
| Region | 1 | 2 | 02 |
| Subregion | 2 | 4 | 04 |
| Basin | 3 | 6 | 06 |
| Subbasin | 4 | 8 | 08 |
| Watershed | 5 | 10 | 10 |
| Subwatershed | 6 | 12 | 12 |


United States Geological Survey (producer, licensor)
Google Earth Engine (host)
STAC Version 0.6.0
Keywords hydrology, usgs, water, watershed, wbd
License proprietary
Temporal Extent 4/21/2017, 5:00:00 PM - 4/22/2017, 5:00:00 PM
Citation Coordinated effort between the United States Department of Agriculture-Natural Resources Conservation Service (USDA-NRCS), the United States Geological Survey (USGS), and the Environmental Protection Agency (EPA). The Watershed Boundary Dataset (WBD) was created from a variety of sources from each state and aggregated into a standard national layer for use in strategic planning and accountability. Watershed Boundary Dataset for HUC# [Online WWW]. Available URL: ( [Accessed 22/04/2017].
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