Revision History for U.S. Geological Survey Techniques and Methods 11-A3 U.S. Geological Survey and U.S. Department of Agriculture, Natural Resources Conservation Service Federal Standards and Procedures for the National Watershed Boundary Dataset (WBD) ----------------------------------------------------- Posted online March 11, 2009 - First Edition This document provides guidelines, requirements, and procedures for expanding and revising the previous U.S. Geological Survey (USGS)-Natural Resources Conservation Service (NRCS) national data published in 1994. Expansion is accomplished by creating two additional levels of detailed hydrologic unit boundaries nested within the 1:250,000-scale hydrologic units, and revision occurs through increasing the data resolution to 1:24,000-scale in the conterminous United States, 1:25,000 scale in the Caribbean, and 1:63,360 scale in Alaska. The guideline contains details for compiling the two additional levels, Watersheds (5th-level, 10-digit hydrologic units) and Subwatersheds (6th-level, 12-digit hydrologic units), to be incorpoted into the WBD. ----------------------------------------------------- Revised and reposted June 2011 - Second Edition Criteria for coastal areas, including open-ocean, nearshore, islands, lakes and reservoirs, were pulled out of section 3.5, Geomorphic Considerations for Hydrologic Units, and moved into a new section 3.7, Coastal Considerations for Hydrologic Units. A new section introducing optional 14-and 16-digit hydrologic units was added as section 3.6. Removed the legacy hydrologic unit naming structure and replaced it with the -digit annotation throughout the entire document (for example, 10-digit hydrologic unit). Section 8:Preparing Data for Certification was updated to Section 8:Preparing WBD Data for Submittal. Figures were added to help clarify concepts outlined in the document. ----------------------------------------------------- Revised and reposted September 1, 2011 - Second Edition Minor word changes were made, URLS for the NOAA Three Nautical Mile Line were updated, a URL that is no longer maintained was deleted from a reference citation. p. 15, section 3.7,. Coastal Considerations for Hydrologic Units: Superseded information in paragraph 2 about representing the National Oceanic and Atmospheric Administration (NOAA) Three Nautical Mile Line and the Uniform Resource Locator (URL) for obtaining NOAA nautical charts have been replaced by current information and the current URL. p. 29, section 4.2.3, Reference Maps: Superseded information in paragraph 2 about representing the NOAA Three Nautical Mile Line and the URL for obtaining NOAA nautical charts have been replaced by current information and the current URL. p. 44, Section 6.2.17, Polygon Attribute Summary: The example of a 12-digit name attribute in the eighth table row and the seventh column has been changed, and an extra table row for the 10-digit name attribute has been deleted. p. 55, References: A URL that no longer exists has been deleted from the citation for Federal Geographic Data Committee, 2001. ----------------------------------------------------- Posted online May 2012 - Third Edition Section 3.6 was changed from Optional 14-and 16-digit hydrologic units to Coastal Considerations for Hydrologic Units. Section 3.7 was changed from Coastal Considerations for Hydrologic Units to Optional 14-and 16-digit hydrologic Units. Additional information was provided in Section 5.4 regarding data harmonization with Canada and Mexico. Section 6.2, Database Schema for Attribution of Hydrologic Unit Polygons, was reorganized and additional information was provided for each attribute within the WBD. Section 8, Preparing Data for WBD Submittal, was updated to Data Revisions, Checkout, Editing, Verification, and Submittal. This section includes information about the updated editing process. Original appendices were reoganized and additional appendices were added. Figures were reviewed and updated as needed. Additional figures were also added. ----------------------------------------------------- Posted online September 2013 - Fourth Edition Minor revisions and verification of URLs occured between the third and fourth editions. Section 6.2.1, Changes to Data Model Due to Integration with NHD, was updated to Section 6.2. Additional subsections within 6.2 were moved to new Sections 6.3, Database Schema for Attributing Hydrologic Unit Polygons; 6.4, Database Schema for Attribution of WBD Lines; and 6.5, Metadata. Moved the Abbreviations and Acronyms Appendices to the beginning of the document. ----------------------------------------------------- Posted online October 2022 - Fifth Edition This version includes a wholesale reorganization of report content and layout. Additional information and figure were added to explain optional 14-and 16-digit hydrologic units, including the renaming of the Standard and Remnant Option section to Major Tributary Option. Data Editing and Quality Assurance section was updated to reflect current editing processes and tools. Required Base Data section was updated to reflect current base data standards, moving from DRG to 3DEP, as the standard for delineation of hydrologic units. Added information about spatial integration of the National Hydrography Dataset (NHD) with the WBD. Verified and replaced URLs and references as needed. Figures and tables were reviewed and updated as needed. Additional figures and tables were created to help clarify concepts outlined in the document. -----------------------------------------------------