Description: This data set is a complete digital hydrologic unit boundary layer to the Subbasin (8-digit) 4th level for the entire United States. This data set consists of geo-referenced digital data and associated attributes created in accordance with the "Federal Guidelines, Requirements, and Procedures for the National Watershed Boundary Dataset; Chapter 3 of Section A, Federal Standards, Book 11, Collection and Delineation of Spatial Data; Techniques and Methods 11-A3" (04/01/2009). http://www.ncgc.nrcs.usda.gov/products/datasets/watershed/index.html . Polygons are attributed with hydrologic unit codes for 1st(Region), 2nd(Sub-Region), 3rd(Basin), and 4th(Sub-Basin) Hydrologic Unit Level codes, names, Sub-Basin acres and square miles.
Copyright Text: Funding and support for the Watershed Boundary Dataset (WBD) were provided by the Natural Resources Conservation Service, the Environmental Protection Agency, and the United States Geological Survey. Representatives from the U.S. Geological Survey and Environmental Protection Agency contributed a substantial amount of time and salary towards quality review and updating of the dataset in order to meet the Federal Standards for Delineation of Hydrologic Unit Boundaries.
Description: This data set is a complete digital hydrologic unit boundary layer to the Watershed (10-digit) 5th level for the entire United States. This data set consists of geo-referenced digital data and associated attributes created in accordance with the "Federal Guidelines, Requirements, and Procedures for the National Watershed Boundary Dataset; Chapter 3 of Section A, Federal Standards, Book 11, Collection and Delineation of Spatial Data; Techniques and Methods 11-A3" (04/01/2009). http://www.ncgc.nrcs.usda.gov/products/datasets/watershed/index.html . Polygons are attributed with hydrologic unit codes for 4th level sub-basins, 5th level watersheds, name, size, downstream hydrologic unit, type of watershed, non-contributing areas and flow modification.
Copyright Text: Funding and support for the Watershed Boundary Dataset (WBD) were provided by the Natural Resources Conservation Service, the Environmental Protection Agency, and the United States Geological Survey. Representatives from the U.S. Geological Survey and Environmental Protection Agency contributed a substantial amount of time and salary towards quality review and updating of the dataset in order to meet the Federal Standards for Delineation of Hydrologic Unit Boundaries.
Description: This New York State Riparian Opportunity Assessment project generated a set of variable width riparian buffers for the purpose of describing the ecological condition of the riparian zone. Buffers were based on the NHD High Resolution Flowlines data set, using the Riparian Buffer Delineation Model and associated methods, developed by Ann Maclean and Sinan Abood: http://www.sfi.mtu.edu/muses/GIS_Riparian.htm. The Riparian Buffer Delineation model is based on an estimated of 50 year flood height, which we extrapolated from Stream Stats flow data and water gage data in New York State. Because estimating the 50 year flood height required such extrapolation, these buffers should never be used to estimate the location or extent of potential flooding. They are an estimate of an ecological boundary only.THESE BUFFERS SHOULD IN NO WAY BE USED TO PROJECT OR ESTIMATE FLOOD RISK. For flood risk maps please see the FEMA website:https://www.fema.gov/national-flood-insurance-program-flood-hazard-mapping. For more information on the Riparian Opportunity Assessment project and the methods used, please refer to project report, located on the website: http://nynhp.org/treesfortribsny