INTERAGENCY MEETING ON SPATIAL WATER DATA
March 20, 1998, at 9:00 a.m.-12:30 p.m.
Main Interior Building, Room B270
1849 C Street, N.W.
WELCOME, INTRODUCTIONS AND OPENING REMARKS: Seventeen representatives
of eight agencies attended the meeting to discuss Federal activities involving
spatial water data. The
U.S. Geological Survey (USGS) /Water Information Coordination Program (WICP)
sponsored the meeting in consultation with representatives of the Federal Geographic
Data Committee (FGDC). Nancy Lopez, Chief of the Office of Water Information
Coordination, chaired the meeting. A list of attendees is below:
PURPOSE OF THE MEETING: The group met for the following general purposes:(1) To exchange information about spatial water data activities that are underway in the Federal sector, (2) to identify water-related spatial data issues that need to be coordinated among the agencies and
with other organizations, and (3) to "reinvent" the Subcommittee on
Spatial Water Data that operated during the early 1990's under the
sponsorship of the WICP and the FGDC.
Because discussions were lively, the group was not able to cover
spatial datasets needed for watershed assessment and restoration. The group will hold a special meeting in the next few weeks to consider those important issues. The watershed assessment concerns are high priority because of the very challenging deadlines for Unified
Watershed Assessments in the President's recently announced Clean
Water Action Plan. Based on those assessments hundreds of millions of dollars will be distributed nationwide to restore watersheds and
improve water quality protection.
The following notes are divided into four sections as follows: Action
items, status of selected spatial water data activities, major issues
identified during the meeting, and preliminary discussion draft terms
of reference for the Subcommittee on Spatial Water Data.
ACTION ITEMS: The group identified next steps, as follows:
USGS/WICP-Hold a meeting in less than a month on spatial data
for watershed assessment. Include a briefing on digital elevation
data at that meeting.
USGS/WICP-Distribute the guidelines for delineating and
digitizing higher resolution watershed boundaries for review and
approval by Federal agencies within 30 days.
USGS/WICP-Once the Watershed Boundary Dataset guidelines are
distributed, hold a briefing seminar for Federal agencies. The
purpose of the meeting would be to review the guidelines and explain
the rationale for the approaches recommended in the guidelines.
All Attendees-Before the next meeting review and comment on the preliminary discussion draft for Terms of Reference (Terms) for the Subcommittee on Spatial Water Data.
USGS/WICP and FGDC-Once agencies have an opportunity to
comment, then the revised Terms will be distributed to the Advisory
Committee on Water Information and the Federal Geographic Data
Committee for review and approval.
All Attendees-Identify additional people and organizations that need to participate in future meetings. For example, a representative from the Federal Emergency Management Agency should be invited to attend the next meeting to discuss Digital Flood Insurance Rate Maps. As soon as possible, the Subcommittee needs to convene and begin operating as a national forum with meetings open to the public.
STATUS OF SELECTED SPATIAL WATER DATA ACTIVITIES. Speakers from
different agencies presented information about the status of spatial
water data activities related to both fresh water and marine
environments. Not all water-related Federal spatial data projects
were represented at the meeting, but several key projects were
discussed. Future meetings will include additional organizations and activities. Each speaker provided handouts. Instead of the hardcopy handouts, homepage addresses are provided with these meeting notes.
National Hydrography Dataset (NHD). Tommy DeWald/U.S. Environmental
Protection Agency (EPA) discussed the joint project between EPA and
the USGS to create a National Hydrography Dataset that combines the
DLG Hydrography file at 1:100,000 scale with the attributes from EPA's River Reach Files. The NHD's primary use will be as a nationally
consistent addressing system for surface water features that preserves hydraulic continuity. The final product will be a nationally
consistent, topologically integrated dataset that can be accessed by
Hydrologic Cataloging Unit. The NHD will include flow direction for
each reach and will match across Cataloging Units. Tommy estimated
that the work will be completed by early in 1999. The developers of
the NHD intend that the system be improved/expanded over time. For
example, higher resolution information and additional data could be
produced over time. For more information see <http://nhd.usgs.gov/>.
Proposal for Development of an NSDI Hydrographic Data Content
Standard for Coastal and Inland Waterways. Nancy Blyler/Corps of
Engineers discussed this proposed dataset that is intended to support waterway navigation applications. This Standard will consist of a feature/attribute/domain, catalog consistent with the Spatial Data Transfer Standard/Federal Information Processing Standard. The FGDC Standards Working Groups has reviewed the proposal, and it will be released for public review soon. The proposal is in a fairly early phase of development, and information about the specific features and attributes to be included is not available. The point of contact for this FGDC proposal is Kevin Backe.
Proposal for a National Shoreline Data Standard. Millington
Lockwood/National Oceanic and Atmospheric Administration (NOAA)
discussed a variety of activities related to shoreline data standards.
These included the Revised Proposal for a National Shoreline Data
Standard (Metada Profile for Shoreline Data) that the FGDC's
Batheymetric Sucommittee is sponsoring. The Shoreline Data Standard
will include a "stylized template" based on the meta data standard,
bibliography, and glossary. Millington also discussed the Charleston,
SC, Shoreline Standard Meeting, a contract to revise and update the
book entitled Sea and Shore Boundaries by Shalowitz, and many other
activities. Millington indicated that NOAA is digitizing the nation's
coastline from its compilation materials that were developed mostly
over the last 20 although some are from much older compilations. He
indicated that these NOAA digital shorelines should be the source for
Federal agencies. For information see
Higher Resolution Hydrologic Units/Watershed and Subwatershed
Boundaries. Tom Iivari/Natural Resources Conservation Service (NRCS)
and Bob Pierce/USGS discussed the status of efforts to subdivide and
digitize the 8-digit Hydrologic Units of the United States. The NRCS
State Offices are coordinating this work with State government
agencies that are emphasizing natural basin boundaries. The NRCS
state offices are now delineating and digitizing the HU's at the 5th
and 6th coding levels generally using 1:24,000-scale maps. In areas
of low relief, field work is required. The NRCS Headquarters provided
the field offices a National Instruction for conducting the
delineation and digitizing effort. The Kansas State Office has
completed the delineations and digitizing, and the resulting products have been reviewed and approved. The status of other State Office
efforts varies widely and much work remains before the effort is
complete early in the next century. Bob is providing technical
consultation and review to support the NRCS delineation and digitizing effort. For more information see: <http://www.usda.gov>.
To document guidelines for a widely accepted, nationally consistent
dataset of watershed boundaries, Bob has conducted an informal
interagency review and revision of the NRCS Instruction. The result
is a draft of consensus specifications and guidelines for subdividing and digitizing the HU's. Once Federal agencies have approved the consensus draft, it will be provided for public
review and then adoption by FGDC and the WICP Advisory Committee on
Water Information. The resulting guidelines can be used to create a
nationally consistent Watershed Boundary Dataset (WBD) for the
National Spatial Data Infrastructure. Some issues, such as
shorelines, will be resolved later. It is the intent of NRCS that
their digital boundaries will closely track the consensus standards,
so that they can be used with little modification as the WBD. For the most recent draft interagency guidelines see: <http://ga.water.usgs.gov>.
MAJOR ISSUES IDENTIFIED DURING THE MEETING. Participants identified
many issues during the above presentations about interrelationships
among the activities presented. Highlights of these issues are
All of the above projects have significant potential for
application together in numerous combinations. These guidelines,
standards and datasets should not conflict, cause confusion, or become unnecessarily costly to apply because of failures to coordinate their development.
Resolution of spatial water data issues needs to occur
through an open process that involves all levels of government and the private sector. Joint sponsorship through the ACWI will provide a national forum chartered through the Federal Advisory Committee Act for such collaboration with the water resources community. Joint
sponsorship through the FGDC will ensure appropriate cooperation at
the national level with related spatial data interests.
The NHD, Waterways Data Content Standards, and Shoreline
Standards all appear to share some important hydrographic spatial data features and attributes that need to be coordinated across
Significant work is needed to address shoreline and coastal
spatial data issues so that applications can share the "underlying
line work" and exchange information effectively. It is especially
important that data for specific areas of the coast can be
located/identified across disciplines.
The priority for developing nationally consistent watershed boundaries has increased dramatically because of the use of watersheds as the geographic unit for implementing the President's Clean WaterAction Plan. The President has requested more than $500 million in additional funding for this initiative beginning in Fiscal Year 1999. Federal agencies, states and local entities have all "done their own thing" in delineating and digitizing watershed boundaries. Without consistent guidelines and datasets, the costs for acquiring,
aggregating, assessing and reporting watershed information across
jurisdictions will be much higher than they need to be.
Completely automated efforts to delineate watershed
boundaries do not yield the necessary accuracy for most applications. Recent technical advances through the EROS Data Center will allow
integration of manual and automated techniques for delineating
watershed boundaries using Digital Elevation Models (DEM's). The DEM data are used to create a first approximation of the boundaries. Then the approximate boundaries are overlaid on scanned Digital Raster Graphic (DRG) images of 1:24,000-scale USGS topographic maps. Viewing both sets of data, the boundaries are adjusted to the DRG contours. This approach can significantly reduce the cost of manually
delineating many areas of the country. The USGS contacts for this
work are Susan Greenlee/EROS and Alan Rea/OK District.
For information about the National Elevation Database see: <http://ned.usgs.gov/>.
There is a critical need for higher vertical and horizontal
resolution DEM's for water-resources applications. Currently, the
vertical accuracy for DEM's is about 15 feet.
As an alternative to using DEM's and hydrography information for delineating watershed boundaries, the National Weather Service is using flow direction grids. Flow grids have the added benefit of serving as calculation units for watershed models.
Water resources agencies need to coordinate their dataset
production and standards/guidelines development activities with FGCD
entities. Also, FGDC efforts need to be coordinated with ongoing water resources work outside the FGDC process. To achieve needed coordination, the Subcommittee on Spatial Water Data needs to be reestablished. The ACWI agreed to sponsor the group at its February meeting.
DRAFT TERMS OF REFERENCE FOR THE SUBCOMMITTEE. After the above
discussions, Nancy Lopez distributed a preliminary discussion draft of
Terms of Reference for the Subcommittee on Spatial Water Data. The
Terms provide for: joint sponsorship by the ACWI and the FGDC,
operation of the Subcommittee as an open process with public
participation, and consideration of both fresh water and marine
issues. Nancy indicated that significant revision and consideration
is needed to achieve a draft that is ready for the next steps in