Description: WaterHydro_WBD12VT was developed by NRCS. The boundaries on consistent with Vermont's Hydrography Dataset (VHD). This data set is a digital hydrologic unit boundary layer at the Subwatershed (12-digit) 6th level for the State of Vermont. The original data set was developed by delineating the boundary lines on base USGS 1:24000 scale topographic quadrangle, and digitizing the delineated lines. Digital Raster Graphics (DRG) images were used to update and correct the data set to meet the new FGDC Federal Standards for Delineating Hydrologic Unit Boundaries. This data set consists of geo-referenced digital map data and associated attributes created in accordance with the FGDC Proposal, Version 1.0 Federal Standards for Delineation of Hydrologic Unit Boundaries 3/01/02 (http://www.ftw.nrcs.usda.gov/huc_data.html). The map data are in a statewide coverage format and include complete coverage of the entire state of Vermont, and small parts of surrounding states and Quebec Province. The hydrologic unit ID code attached to each delineated polygon is linked to the attribute data.