National Bulletin:

340-13-7  

Date:

April 23, 2013 

Subject:

SPA - Watershed Based Management Performance Management Using Hydrologic Unit Codes

Action Required By:  May 20, 2013

Purpose.  To ensure consistency in data and reporting in accordance with Title 340, General Manual (GM), Part 403, Subpart B, Section 403.12C, and establish annual version control when using hydrologic unit boundaries as spatial boundaries for performance management purposes through agencywide adoption of the Watershed Boundary Dataset (WBD) in accordance with 170-GM, Part 400, Subpart D, Section 400.38A(1).    

Expiration Date.  September 30, 2014   

Background.  NRCS provides reports to many different audiences.  Agency data must be authoritative and grouped in a specific, measurable way to identifiable units, such as counties, States, and service center areas.  Performance within these spatial areas is tied to funding and outcomes of the funding investment in those areas as well.  Increasingly, the agency is being asked to provide data for watersheds of various scales.  For data to be provided by watersheds, the delineated hydrologic unit (HU) used to spatially identify performance must be authoritative and consistent across all agency data uses.

During the 1970s, the U.S. Geological Survey (USGS) developed a hierarchical hydrologic unit code (HUC) for the United States.  During the late 1970s, NRCS initiated a national program to further subdivide HUs into smaller watersheds for water resources planning.  In the early 1990s, NRCS started to delineate hydrologic units to the 10th and 12th level by using Geographic Information Systems (GIS) to meet 1:24,000 National Map Accuracy Standards.  With increased interest from other Federal, State, and local entities, this initiative became an interagency effort that has become the Watershed Boundary Dataset (WBD).

The WBD provides a hydrologically correct, seamless, and consistent national GIS database at a scale of 1:24,000 that has been extensively reviewed and matches to a minimum the USGS topographical 7.5-minute quadrangles.  The mapping is done by the use of GIS, incorporating digital elevation models, digital raster graphics, and a variety of geospatial data and techniques.  The national standard is overseen by the Subcommittee on Spatial Water Data Federal Geographic Data Committee and the Advisory Committee on Water Information.  The quality standards and procedures ensure that HU boundaries are accurate and consistent nationwide and that the digital database is and will be usable with other natural resource digital data layers in a GIS.  In 2012, the stewardship of the national WBD was transferred from NRCS to the USGS.

The Conservation Delivery Streamlining Initiative (CDSI) and such tools as Conservation Desktop require use of the WBD.  HUC8-, HUC10-, and HUC12-level watershed information will be associated to all conservation technical and financial assistance datasets in the Conservation Desktop.  In this context, WBD data is intended to be used as a tool for areawide planning, State resource assessments, and client-based planning activities. Additionally, as part of compliance with 340-GM, Part 403, Subpart B, Section 403.12C, other agency data tools (PRS, IDEA, and others) use HUCs as part of the location assignment and are currently updated annually.

To ensure compliance with 170-GM, Part 400, Subpart D, Section 400.38A(1) requirement that all watershed boundaries are consistent with the latest industry standards and held at the NRCS National Geospatial Management Center (NGMC), NRCS will be using only WBD to identify HUCs for use in agency performance and other data identification and management.  In addition, within-agency version control will be established to ensure consistency of data and boundaries within fiscal years. Enter background>         

Explanation.  Any use of non-WBD-based watershed boundaries or names will not be supported and must be phased out. 

All agency programs, initiatives, applications, and tools, including CDSI and Conservation Desktop, will use an annual “snapshot” of the WBD for a trackable, consistent, and unified data source within a fiscal year.  Although the WBD is updated continuously by WBD data stewards, and these updates may be available for download from USDA Data Gateway or USGS, the annual snapshot will be used for agency programs, initiatives, applications, and tools.

All data systems will hold the same version of the WBD, as provided by NGMC, with use beginning on October 1 of each fiscal year.  The updated WBD will be used consistently across all agency data functions for a trackable and unified source for agency data within a fiscal year.

For State-level or other agency needs, the version of the WBD that is the annual official version will be identified as such and provided on the USDA Data Gateway.

As of October 1, 2013, all agency performance will be collected and managed based on the WBD using the version control method described herein.   

Contact.  For questions regarding watershed boundaries and geospatial data management, contact Steven Nechero, Leader, Geospatial Data Management Branch, NGMC, at (817) 509-3366 or by email at Steven.Nechero@ftw.usda.gov.  For questions about agency data management, contact Letitia Toomer-Jones, Data Team Leader, Resource Economics, Analysis and Policy Division, Deputy Area for Strategic Planning and Accountability, at (301) 504-1233 or by email at Letitia.Toomer-Jones@wdc.usda.gov.      

 /s/

LESIA A. REED 
Deputy Chief for                                              
Strategic Planning and Accountability





MICHEAL L. GOLDEN
Deputy Chief for
Soil Science and Resource Assessment