M'AVYBS
News Flash
Ltlition
Indexing Waterbodies Using
the EPA Reach File
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Special Edition
RF3 Indexing
April 1995
Office of Water
EPAWBS
News Flash
Section 305(b) Waterbody System
WBS Data, Mapping
Capabilities, and Spatial
Analysis
The Waterbody System (WBS) database provides a
convenient means for storing assessment informa-
tion organized around water quality resource units
called waterbodies. Once assessment information
is entered on beneficial use status or causes and
sources of pollution for each waterbody, the WBS
program can generate lists and summary tables
useful in the preparation of the Section 305(b)
reports. From the late 1980s when the current
format for the WBS database emerged, there was
also a clear intent to provide mechanisms to
produce maps and other spatial analysis products
using the waterbody-specific information.
The Alpha version of the EPA Reach File Version
3.0 (RF3) is now available as a tool for achieving
these mapping and geographical analysis objec-
tives. With earlier, less detailed versions of the
Reach File, manual coding forms were used to
carry out an operation called Reach File indexing.
The resulting indexing codes indicated which
features in the Reach File would be associated with
specific waterbodies. With the much larger set of
arcs available in RF3, software tools are indispens-
able in completing the indexing process, and
Geographical Information Systems (GISs) become
attractive environments for using the indexed data
layers.
This special issue of the Waterbody System
News Flash presents background information on
approaches for geocoding the locations of
waterbodies with RF3. Examples are provided on
using the resulting GIS coverages to support the
Section 305(b) process and for other spatial analy-
sis applications. The Reach File provides the
hydrologic framework for linking many types of
spatial data layers. GIS coverages can be created
based on georeferenced monitoring stations, point
source discharge outfalls, surface drinking water
intakes, and other point attribute information.
These data layers cart be combined with coverages
dealing with land use, transportation corridors, or
the boundaries of cities, counties, and other
governmental units. Because RF3 provides a series
of traces networked to simulate natural drainage
systems, indexed data layers can also be used to
construct hydrological routing models for model-
ing pollutant fate and transport processes.
The focus of this special issue of News Flash is the
indexing of waterbodies to assist State monitoring
and assessment programs. The essential first step
in this process is to translate the pattern a State has
adopted in delineating its waterbodies into a
digitized format using features contained in the
Reach File. In this issue, some typical patterns of
waterbody delineation are highlighted and sample
GIS maps are provided.
Patterns in Waterbody
Delineation
States have chosen a variety of ways to define their
waterbodies. Essentially, a waterbody is a homoge-
neous classification that can be assigned to nvers,
lakes, estuaries, coastlines, or other water features.
Most States find their inland rivers to be the
greatest challenge in defining a suitable set of
waterbodies, thus the examples provided here
stress indexing work on river waterbodies.
Linear Reaches
Some common patterns appear in the way States
delineate waterbodies involving rivers and
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Special Edition RF3 Indexing April 1995
The Waterbody System Database and Its Role in RF3 Indexing
EPA designed the Waterbody System (WBS) as a State and national database for storing and analyzing
water quality assessment information. The WBS tracks use support information for water units called
waterbodies. States, Territories, American Indian Tribes, and River Basin commissions define their own
waterbodies to best serve their management needs. An individual waterbody may consist of a short stretch
of stream, an individual lake, or the rivers and streams of an entire watershed. Usually, waterbody bound-
aries correspond to significant hydrologic or ecologic features such as watershed boundaries. The WBS
recognizes rivers, lakes, estuaries, tidal wetlands, freshwater wetlands, Great Lakes shorelines, and coastal
shorelines as different types of waterbodies.
The WBS provides a convenient way for a State to track a wide range of assessment information for its
designated waterbodies. Data fields track information on designated use support induding aquatic life
support, human health risks related to fish and shellfish consumption, and recreational use support. The
WBS provides data fields to document causes and sources of pollution impairing full attainment of State
water quality standards in each designated waterbody. Currently, EPA supports a PC-based software
program to create the WBS ifies and handle reporting and data retrieval functions. WBS information is also
ported to a special SAS library on the EPA National Computer Center (NCC) mainframe. EPA is working
with States to identify ways the basic WBS data structure can be implemented on workstation or other
computer platforms.
Once a State enters the data, it can use the WBS to generate a variety of summary reports and lists that
simplify preparation of its 305(b) water quality assessment reports. EPA can also use all WBS data as a tool
in preparing the National Water Quality Inventory Report to Congress. For the 1996 305(b) cyde, the PC
WBS software will be provided with enhanced reporting capabilities, including the ability to join in-house
data sets with the basic WBS files.
EPA originally designed the WBS to facilitate analyses of water quality information for entire States or
other large geographic areas. The future design for the WBS will emphasize more detailed spatial analyses
and mapping capabilities. The key to implementing these new approaches is to index a State’s waterbodies
to the EPA Reach File. EPA is offering grants for States interested in getting their waterbodies and related
305(b) information indexed to the Reach File. For further information, call Jack Clifford at EPA Head-
quarters, 202-260-3667.
streams. One pattern is to employ linear reaches of
stream, which is often the way States catalog listed
streams with specific designated beneficial uses in
their water quality standards. Such a system can
often work quite well for that subset of RF3
corresponding to perennial streams. For instance,
the State of Ohio has an official nver mile system
that divides its perennial stream network into
approximately 4,000 stream reaches, with most
reaches comprising a run of stream falling between
tributary confluence points. Ohio delineated each
of these perennial stream reaches as a separate
waterbody. This type of waterbody pattern is
illustrated in Figure 1 (see pocket at back of this
newsletter for oversized figures).
A pattern such as that illustrated for Ohio has
several attractions. Such a pattern will often
correspond very closely with the way beneficial
uses have been assigned to stream reaches. This
can simplify the data mtegration process involved
in relating monitoring, modeling, and inventory
information to the assessment values stored in
WBS for such items as use attainment or causes
and sources of pollution. On the other hand, this
pattern of numerous short reaches of stream can
become complicated to set up and maintain if a
State must delineate large numbers of river
waterbodies. If these data management issues are a
constraint, other styles of waterbody delineation
can be considered.
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Special Edition RF3 Indexing April 1995
Watershed Patterns
An alternate method of delineating waterbodies is
to group RF3 traces within small watershed
polygons. Several States have used this approach
to define a set of primary waterbodies. An example
of this pattern is presented in Figure 2 for Virginia.
In Virginia, the polygons were adapted from the
State’s VirGIS small watersheds. This GIS system is
supported through Virginia Tech and has been
adopted for the selection of target watershed
implementation work in Virginia’s Section 319
Nonpoint Source Management Program. The U.S.
Department of Agriculture (USDA) Soil Conserva-
tion Service (SCS)—now the Natural Resources
Conservation Service (NRCS)—has defined a
system of nested watersheds within 8-digit USGS
Cataloging Units. The 11-digit or the even smaller
14-digit SCS/NRCS watersheds are good candi-
dates to consider for States interested in imple-
menting a polygon-based approach to waterbody
delineation.
For those States for which a digitized set of
watershed polygons is available, a watershed-
oriented approach can vastly simplify the effort
required to create an initial waterbody coverage.
Special PC-based software tools are available to
facilitate this type of polygon indexing, which can
also be accomplished using ARC-INFO proce-
dures. Various digital line graph (DLG) and trace-
feature codes within RF3 can be used to select
either the full set of river-type Reach File traces or
a subset such as perennial streams to geocode as
waterbodies. Where needed, special traces within a
polygon can be defined as separate waterbodies.
For instance, river segments with special beneficial
use classifications such as drinking water supplies
or outstanding resource waters may be distin-
guished from other river traces where use assign-
ments are made in a more general fashion. If there
are a great number of exceptions to the rule of
grouping reaches within a watershed into a single
waterbody, the polygon method quiddy loses its
advantages of simplicity and technical efficiency.
Sometimes, however, the way traces are released
from a watershed-oriented pattern may have
enough regularity to help define another set of
indexing techniques.
Hybrid Approaches
In some States, a hybrid pattern emerges involving
a combination of the linear stream reaches and the
watershed polygons. A good example is the
approach adopted in Kansas, as illustrated in
Figure 3. For larger alluvial rivers, waterbody
delineation is linear. For tributary watersheds to
these large rivers, a watershed approach is
employed. Digitized polygons based on the SCS
11-digit framework are valuable tools for indexing
these watershed-oriented waterbodies on the
tributary systems.
Analyzing and Mapping
Assessment Information
with Indexed Waterbodies
Indexing waterbodies to RF3 allows us to organize,
display, and analyze data on use support and
impairment, as well as the causes and sources of
pollution, at the subwaterbody level (the reach
segment). Since reach segments are defined “from
confluence to confluence,” this allows the identifi-
cation of specific portions of the stream associated
with the environmental problem. This allows
mapping of thematic layers (e.g., use support,
causes, and sources) and comparison with data on
water quality monitoring or other information
linked geographically through RF3 as well as with
information that is geocoded but not necessarily
linked to RF3 (e.g., land use categories).
Currently, waterbody system data are defined
geographically only at the waterbody level. For
some information, this may be sufficiently high
resolution. Howevei assessment mformation can
then be displayed only as colors or patterns for
entire waterbodies. This constraint leads to clumsy
presentation of the assessment data (e.g., “red-
colored traces represent waterbodies with some
nonsupport of aquatic life use”). This lack of
spatial resolution reduces the power of the GIS as
an analytical tool. ! /
The WBS database includes a large number of files
for storing different types of assessment informa-
tion. Each of these data tables rncludes special size
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Special Edition RF3 Indexing April 1995
fields to indicate whether an information attribute
applies to the entire extent of the waterbody or
only to some portion. For instance, a State may
record that, on a river waterbody of 30 miles in
total extent, 10 miles have use impairments and
the rest of the stream miles show full support. If
only the waterbodies are geocoded, then providing
appropriate legends for map displays becomes
more complicated. Some examples illustrating this
point are provided in Figure 4 based on materials
from South Carolina. In the first version of a
display from a portion of the Edisto River Basin
(Figure 4a), all the river traces within the SCS 11-
digit basins are assigned uniform color symbols. In
the basin marked with an arrow, note that the
associated caption for this color theme reads:
“Some Degree of Partial or Nonsupport.” The
companion map (Figure 4b) shows a modified
version of this display reflecting the actual condi-
tions reported in South Carolina’s assessment
database for the 1994 305(b) cyde. In this version,
traces within the small watershed polygons have
been given different color codes that represent the
different degrees of use attainment documented by
the monitoring data.
Careful forethought in the initial delineation
process can sometimes minimize the frequency of
situations where an assessment category applies
only to a portion of a waterbody. Still, the large
number of size fields provided in the WBS data-
base makes it easy for this phenomenon to occur,
at least for a few waterbodies. The chance of this
happening increases if there is a complex pattern
in an area for the designation of different beneficial
uses. For instance, a beneficial use such as aquatic
life support may apply to virtually all waterbodies,
while drinking water supply or outstanding
resource waters designations may be in place only
for smaller portions of a watershed. The chances
also increase where watershed-based polygons
form the basis for the waterbody delineations: the
larger the polygons, the greater the odds of
encountering this phenomenon of spatial indeter-
minacy.
The route system data model used by EPA in
indexing State waterbodies provides two route
systems, WBS and SEC. The WBS route system
groups all RF3 arcs (segments) that fall within each
waterbody. This route system can be used to
display information on a waterbody level. It is
useful for presenting some types of information,
but limits resolution to the waterbody level. The
SEG route system is based on the SEC number of
each segment in the RF3 database. Since SEG
numbers are unique within each Cataloging Unit,
starting at 1 and incrementing by 1, a collection of
SEGs defines a specific branch of the waterbody’s
stream reaches. The assessment attributes can then
be developed in event tables that are based on the
reach segment (SEG) and the distance along the
segment. This makes a wide variety of carto-
graphic features available for display and map-
ping. The combination of WBS and SEC route
systems allows display and mapping of data at the
most appropriate level of resolution. The improved
precision illustrated in Figure 4b can be achieved
through applying a SEC route system to the initial
WBS route system in Figure 4a.
South Carolina’s Use of GIS
Data Integration Approaches
Where entire waterbodies seem inappropriate to
reflect the sizes associated with such data entries
as use attainment, additional geocoding instruc-
tions may be needed to achieve the desired results.
For instance, once the basic waterbod.ies have been
defined, a second round of geocoding could add
additional indexing instructions to specify arcs
contained within a particular waterbody to match
the more precise assessment information. This
extra level of indexing allows the types of displays
shown in Figure 4b.
As with the delineation of waterbodies, the use of
computer-based tools provides a manual approach
for creating additional RF3 indexing expressions.
Computer-assisted data integration techniques are
another possibility and these approaches hold
promise for automating much of the within-
waterbody geocoding procedure. In addition to
automating the production of geocoding instruc-
tions for waterbody assessments, these techniques
can be used in many other types of spatial
analysis.
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Special Edition RF3 Indexing April 1995
South Carolina has been a pioneer in implement-
ing these more automated data integration meth-
ods. The pattern South Carolina adopted in its
WBS database used the SCS 11-digit polygons to
delineate river waterbodies. In most cases, all the
river-type RF3 traces within a polygon are associ-
ated with a single river waterbody. Even at this
point in their indexing work, South Carolina was
able to create useful maps applying information
items on use attainment or causes and sources of
pollution to entire waterbodies. In many cases,
however, available assessment information allows
greater degrees of specificity in assigning sets of
RF3 arcs to different degrees of use attainment.
With EPA assistance, South Carolina developed a
collection of GIS-based ARC-NFO AMLs (these
ARC Macro Language statements can be saved as
programs for subsequent use or for incorporation
into elaborate turnkey systems). A goal was to
replicate in the AMLs the same types of data
integration operations that had previously been
performed in a number of piecemeal steps. For
instance, the majority of South Carolina’s moni-
tored assessments are based on results from
STORET sites. GIS layers were created to show the
locations of key monitoring sites at mile positions
along RF3 arcs. This coverage also included
summary statistics based on STOREr retrievals
from the monitoring stations. Information from 622
water quality sites was added to this coverage.
Similar coverages have been created for point
source discharges and for surface water drinking
water intakes.
RF3 contains hydrologic routing information,
making it very easy to start at a given point within
the hydrologic network and then move to other
upstream or downstream arcs. South Carolina was
able to use RF3’s abilities to navigate upstream and
downstream to assign results from its monitoring
station coverage to specific sets of arcs within one
of its watershed river waterbodies. Where the
results of STORET data analyses indicated a
significant number of standards violations for one
or more parameters, a specific set of RF3 arcs could
easily be identified to associate with an assessment
condition, such as Aquatic Life Use Partially
Supported.
A GIS layer with the locations of drinking water
intakes can be combined with monitoring station
information to automate the assessment process for
the drinking water supply beneficial use. A
decision rule can be defined on a distance down-
stream of monitoring sites showing elevated
pathogen indicator levels for which drinking water
impairments are deemed likely. A GIS layer with
point source discharge data can help in deciding
whether standards exceedances documented at
monitoring stations can reasonably be attributed to
point source discharges. Permit compliance and
wasteload allocation data can also be set up in the
GIS environment as fate and transport models.
Even a simple dilution approach can help clarify
such issues as the potential nutrient impacts of
point source discharges on outstanding resource
waters. The displays in Figure 5 illustrate some of
the data layers that South Carolina has developed.
Point attribute coverages from monitoring stations,
discharging facilities, drinking water intakes, or
data from the Toxics Release Inventory (TRI) can
be ported into ARC-INFO coverages. A variety of
polygon coverages, for instance, dealing with land
uses or the information from the U.S. Fish and
Wildlife Service’s National Wetlands Inventory, can
also be overlaid with the sampling station and
facilities layers.
The basic RF3 coverage, combined with even a
handful of additional layers on locations of
waterbodies and key STOREF and point source
discharge sites, can help automate a decision
process that previously involved many intenne-
diate steps and heavy investments in manual labor.
The same data layers of value in automating a
waterbody assessment process can also help with a
number of other tasks, such as:
• Design of water quality sampling networks
• Permit setting and total maximum daily load
(TMDL) calculations
• Siting of new drinking water sources
• Standards reclassifications for outstanding
resource waters.
South Carolina is developing a vision statement to
define its current uses of RF3 and its goals for
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Special Edifion RF3 Indexing April 1995
future applications of RF3 in conjunction with
other data layers. This vision statement is summa-
rized in the highlight on page 7.
Tools for Waterbody Indexing
Various avenues are available for geocoding
waterbodies with RF3:
• A State can use the PC Reach File (PCRF)
software to create indexing expressions that can
then be converted into a GIS layer.
• States can mark up maps showing their
waterbody locations, arid this information can
be converted into a GIS layer using PCRF or
ARC-INFO with contractor support.
• States may have digitized data that can be
converted into a GIS layer with contractor
support.
The PCRF software is a very cost-effective indexing
tool. It runs using very basic PC equipment,
requiring only a VGA color monitor, a mouse, and
about 10 megabytes of free hard disk storage. The
current version of PCRF supports a set of trace
filters. These allow the user to focus attention on
such subsets of RF3 as rivers only or perennial
streams. PCRF makes it possible for all agency staff
to take a look at RF3 and make informed contribu-
tions on how to select features in RF3 to associate
with specific waterbodies. PCRF can also be used
as a production tool. ARC-INFO AMLs are avail-
able to convert the indexing expressions created
with PCRF into GIS coverages. An example is
given in Figure 6 showing actual indexing work
for the Fox River in Wisconsin. EPA provides
technical support for States interested in RF3
indexing with PCRF.
Although marking up maps may not seem very
sophisticated, this approach can work. EPA
technical support can provide special GIS-pro-
duced RF3 base maps. These maps can include
labels derived from the RF3 CU-SEC-MILE
identifiers or names such as those found on USGS
printed maps. If a State has digitized small water-
shed polygons to help define waterbody locations,
these polygons can also be displayed on the base
maps. An example is given in Figure 7 showing a
representation of an original marked up map and
the resulting GIS coverage for the Lower Madd
River in northern California.
If a State has an in-house hydrographic DLC that
contains waterbody locations, the indexing infor-
mation can often be transferred to RF3 using a GIS
process called conflation. This method of overlay-
ing GIS layers also makes it possible to transfer
other information attributes from in-house data
systems to the RF3-indexed layer with WBS
assessment data. For instance, Ohio’s river-mile
DLG system provided a convenient way to locate
waterbodies in RF3. Indexing work with older
versions of the EPA Reach File from Wyoming can
also be conflated with RF3. An example is shown
in Figure 8 of a coverage based on the old Reach
File Version 2 conflated with RF3. Where the
necessary GIS coverages exist, conflation tech-
niques can substantially speed up the waterbody
indexing process.
Once a coverage is created, GIS software tools
currently provide the major platforms for using the
geocoded databases. In addition to ARC-INFO,
PC-based desktop mapping systems provide a
cost-effective platform for using the RF3 coverages.
Although EPA does not endorse any particular
desktop mapping software, many States are
beginning to make good use of such products as
ESRI’s ARCVIEW. For instance, Kansas uses its
indexed waterbodies along with coverages of point
source discharges and other permitted facilities
with PC ARCVrEW. Desktop mapping systems can
often be set up on a laptop computer, which makes
these programs attractive for demonstrations and
for situations when staff from different agency
divisions or different district offices need access to
geocoded data.
A Status Check on RF3
Indexing Work
As of late March 1995, 17 States had begun to
index their waterbodies with RF3. South Carolina
deserves a special note of commendation as the
first State to index its waterbodies to RF3.
Although indexing is a State effort, certain indi-
viduals have made outstanding efforts. For
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Special Edition RF3 Indexing April 1995
South Carolina Department of Health and Environmental Control
Bureau of Water Pollution Control
Present and Future Applications of RF3
— Proposed Vision Statement —
South Carolina’s Bureau of Water Pollution Control has taken a significant step in the development of a
GIS-based water quality assessment methodology through the utilization of the River Reach File (RF3). The
Reach File provides a digital coverage describing the structure and hydrology of the State’s surface waters
based on the 1:100,000 U.S. Geological Survey hydrography layer. All stream reaches have been hydrologi-
cally linked and assigned a unique reach identifier. This identifier will allow attributes anchored to the
1:100,000 RF3 fiie to be easily transferred to larger scales when they become available.
Utilization of the RF3 coverage addresses this agency’s growing demand for a geographically referenced
assessment coverage for the collection, integration, and analysis of water quality information. The hydrog-
raphy coverage serves as the foundation for analyzing the interdependence of water-quality-related
activities associated with river basin development, inducting: monitoring, problem identification and
priontization, modeling, planning, and permitting. The integration of these activities has led to manage-
ment plans and implementation strategies on a watershed basis, allowing the SCDHEC Bureau of Water
Pollution Control to focus its water quality efforts appropriately.
Attributes assigned to the South Carolina RF3 hydrography coverage:
• Water Quality Stations • Aquatic Life Use Support
• Monitoring Data • Recreational Use Support
• Impairment Cause • Overall Use Support
• Impairment Source • Classification of Waters
• Stream Order • Outstanding Resource Waters
• Water Quality Impairments • Modeled Stream Reaches
Current and Future Applications
305(b) Report Requirements
• Calculation of stream mileage associated with various use support levels
• Calculation of stream mileage associated with water quality impairments, causes, and sources
River Basin Management — Watershed Water Quality Management Strategy
• Presentation of graphic evaluations of water quality trend analysis
• Identification of additional/special basin monitoring station locations
• Calculation of stream mileage associated with water dassifications
Identification of Potential Outstanding Resource Waters
• Presentation of quick reviews of water quality conditions within selected areas
• Calculation of distance downstream to nearest potable water supply
• Examination of land use in relation to stream reach location and order
• Examination of probable dilution factors by assessing stream order type
Use of Route System Data Model to Organize GIS Attribute Information
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Special Edition RF3 Indexing April 1995
instance, in South Carolina, Jeannie Eidson clearly
deserves recognition for her work. Other pioneers
include Virginia (thank you, Alison Sinclair) and
New Hampshire (thank you, Don Chesebrough).
Perhaps the best way to summarize the progress in
RF3 indexing is with a map. Figure 9 shows those
States already indexed or where geocoding work is
in process.
Figure 9. RF3 Indexing Progress
During the 1996 305(b) cyde, EPA strongly encour-
ages as many States as possible to begin geocoding
their waterbodies to the Reach File. At present, the
only major hurdles involve the Caribbean and EPA
Region 10, where work is still under way to create
an EPA RF3 database. In the meantime, some
Region 10 States are using available DLGs to create
geocoded systems with very strong resemblances
to the EPA RF3 product. As discussed below, there
is an ongoing process to upgrade the EPA Reach
File. As part of this upgrade process, steps are
being taken to reconcile EPA’s RF3 with existing
data layers in the Pacific Northwest. Therefore,
systems being developed in such States as Wash-
ington should be transferrable to RF3.
Federal Efforts to Make
Available Quality Sources
of GIS Information
On October 19,1990, the Executive Office of the
President, Office of Management and Budget
(0MB), revised Circular A-16,”Coordination of
Surveying, Mapping, and Related Spatial Data
Activities.” The goals of the Circular are to develop
a national digital geographic information resource,
to reduce duplication, to reduce the expense of
developing geographic data, and to increase the
benefits of using available data and ensuring
coordination of Federal agency geographic data
activities. Circular A-16 established the Federal
Geographic Data Committee (FGDC) to promote
the coordinated development, use, sharing, and
dissemination of geographic data. The committee
oversees and provides policy guidance for agency
efforts to coordinate geographic data activities. The
FGDC has also been charged with coordinating
geospatial data-related activities with other levels
of government and other sectors.
Agency responsibilities include providing govern-
ment-wide leadership in developing data stan-
dards, assisting information and data exchange,
and coordinating data collection. The FGDC is
currently composed of representatives from 14
departments and independent agencies induding:
• Department of Agriculture
• Department of Commerce
• Department of Defense
• Department of Energy
• Department of Housing and Urban
Development
• Department of the Interior
• Department of State
• Department of Transportation
• Environmental Protection Agency
• Federal Emergency Management Agency
Library of Congress
• National Archives and Records
Administration
• National Aeronautics and Space
Administration
• Tennessee Valley Authority.
The Departments of Education, Health and
Human Services, Justice, and Labor; the General
Services Administration; the National Capital
c States Indexed or in Process
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Special Edition RF3 Indexing April 1995
Planning Commission; and the Smithsonian
Institution also participate on FGDC subcommit-
tees and working groups.
The FGDC sponsors and participates in confer-
ences and other forums concerning issues impor-
tant to the development of spatial data products.
The committee also publishes the Federal Geo-
graphic Data Newsletter, Summary of GIS Use in the
Federal Government, annual reports, and other
publications of interest to the spatial data commu-
nity. For more information about the FGDC or its
activities or to be added to the newsletter mailing
list, please contact:
Federal Geographic Data Committee Secretariat
U.S. Geological Survey
590 National Center
Reston, VA 22092
703-648-4533 x 55 ( -f. ‘
The FGDC coordinates development of the
National Spatial Data Infrastructure (NSD1), which
is conceived to be an umbrella of policies,
standards, and procedures under which organiza-
tions and technologies interact to foster more
efficient use, management, and production of
geospatial data. The NSDI will facilitate coopera-
tion and interaction among various levels of
government, the private sector, and academia. A
major component of the NSDI currently under
development is a basic framework of digital
geospatial data to act as a foundation for other
data collection activities. This effort is called the
National Digital Geospatial Data Framework, often
simply called the FRAMEWORK data.
The FRAMEWORK is envisioned to indude
information from the following basic categories:
• Geodetic Control Data
• Digital Ortho-imagery
• Elevation Data
• Transportation
• Hydrography
Boundaries of Governmental Units
• Cadastral Data (e.g., boundaries of public
lands, military reservations, and State parks)
FRAMEWORK data should be “data you can
trust” and should be certified as complying with
documented quality control standards. For each
major category of information, the FRAMEWORK
data should be the best data available for specific
types of applications. Although high-resolution
data sets are of obvious interest, the collection will
also contain useful lower-resolution data to
support regional and national applications.
FRAMEWORK data will be made available at the
cost of dissemination, free from use criteria or
constraints, and available in nonproprietary forms.
The EPA RF3 approach is being considered as part
of the FRAMEWORK data.
Upgrades to the EPA Reach File
and STORET Modernization
As part of its data systems modernization efforts,
EPA is implementing significant enhancements to
the Reach File and to its STOREr monitoring
database. STORET modernization was highlighted
at a national workshop held in Dallas in early
February 1995. A three-phase prototyping
approach is being used, with development work
now entering the third phase. The new S1ORET
user interface will organize data entry and analysis
functions into five major modules called business
areas. Prototypes for three of these modules were
presented at the Dallas workshop. The new
STORET system will emphasize mapping and
visualizations as major data summary products.
Surface water monitoring stations will be assigned
RF3 indexing attributes allowing STORET informa-
tion to be transferred to GIS’layers that could be
used with indexed waterbodies and 305(b) assess-
ment data. For additional information on STORET
Modernization, contact the STORET User Assis-
tance Group at 800-424-9067.
EPA is also in the process of implementing major
upgrades to the current RF3-Alpha. The upgraded
product is called RF3-Final or RF3-1996, with a
target release date of February 1996. EPA is
working with the USGS to incorporate digitized
information from the latest lOOK DLG-E (for
Digital Line Graph Enhanced) hydrography files.
A process is being undertaken to match as many
names as possible contained in the USGS
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Special Edition RF3 Indexing April 1995
Geographic Names Information System (GNIS)
and transfer them to attributes associated with
Reach File arcs. An enhanced set of CU boundary
polygons will be used to ensure the correct align-
ment of reaches—especially headwater streams—
within the 8-digit USGS Cataloguing Units. For
lakes and wide rivers, centerlines will be added to
the Reach File to simplify edge-matching with
other data layers and the use of RF3 in hydrologic
routing models.
The RF3 update process will seek to add an
improved navigation model to avoid confusion in
the patterns of hydrologic connectivity for streams
with multiple confluence points or lakes with
complicated patterns of stream input or outflows.
An expanded reach numbering system will be
offered to facilitate the addition of new features
currently unrepresented in the DLG-E linework.
The RF3 upgrades will undergo a quality assur-
ance/quality control (QA/QC) step including a
battery of visual checks using ARC-INFO to ensure
that errors are identified and repaired. RF3-Final
should eliminate a range of minor flaws in the
current RF3-Alpha and make the enhanced Reach
File highly compatible with the spatial analysis
capabffities of ARC-INFO Geographical Informa-
tion Systems.
The EPA WBS News Flash provides a periodic
status report on State and EPA activities
related to the Section 305(b) Waterbody System
(WBS) database and information on indexing
waterbodies to the Reach File. Send your
comments on this special edition of the WBS
News Flash to: Jack Clifford, U.S. EPA (4503F,
401 M Street, SW, Washington, DC 20460,
202-260-3667). EPA technical support is
available for users of the WBS database and
States interested in RF3 indexing. Questions
involving policy issues should be directed to
Mr. clifford. Help on routine technical matters
is available by calling Bill Cooter at Research
Triangle Institute, 919-541-5918.
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