Watersheds

Water hydrologic unit boundaries 12-digit

Description:
FUTURE MAP LAYER: Watershed boundaries define the aerial extent of surface water drainage to a point. The intent of defining hydrologic units (HU) for the Watershed Boundary Dataset is to establish a base-line drainage boundary framework, accounting for all land and surface areas. The selection and delineation of hydrologic boundaries are determined solely upon science-based hydrologic principles, not favoring any administrative or special projects nor particular program or agency. At a minimum, they are being delineated and georeferenced to the USGS 1:24,000 scale topographic base map meeting National Map Accuracy Standards (NMAS). A hydrologic unit has a single flow outlet except in coastal or lakefront areas. As stated by the Federal Standard for Delineation of Hydrologic Unit Boundaries,

Resolution/Data Scale:
Sample site

Unit Type:

Data Type:
Vector

Projection/Datum:
Geographic, NAD83

Data Source:
NCSS Soil Characterization Database

Update Schedule:
2009

Notes:

Website:
http://www.ncgc.nrcs.usda.gov/products/datasets/watershed/index.html

Creator:
USDA Natural Resources Conservation Service (NRCS)

Preferred Citation:

Legend Image: