# Subbasin

HU_8_Name:
Hudson-Hoosic. New York, Massachusetts, Vermont.


# Subwatershed

HU_12_Name:
Black River-Branch Brook to Duttonsville Gulf


HU_12_Name:
Mill Creek-headwaters to East Wallingford


HU_12_Name:
Williams River-headwaters to Middle Branch


HU_12_Name:
West River-Winhall River to Ball Mountain Brook


HU_12_Name:
West River-Ball Mountain Brook to Wardsboro Brook


HU_12_Name:
West River-Wardsboro Brook to Grassy Brook


# Watershed

HU_10_Name:
Connecticut River-Sugar River to Bellows Falls


HU_10_Name:
West River-headwaters to Wardsboro Brook


HU_10_Name:
Deerfield River-headwaters to Sherman Dam


HU_10_Name:
Connecticut River-Bellows Falls to Vernon Dam


HU_10_Name:
Connecticut River-Vernon Dam to Deerfield River


# NHDFCode

Description:
Reservoir: Reservoir Type = Disposal; Construction Material = Earthen


Description:
Reservoir: Reservoir Type = Disposal; Construction Material = Nonearthen


Description:
Canal/Ditch: Canal/Ditch Type = Aqueduct


Description:
Dam/Weir: Construction Material = Earthen


Description:
Dam/Weir: Construction Material = Nonearthen


Description:
Lake/Pond: Hydrographic Category = Intermittent


Description:
Lake/Pond: Hydrographic Category = Perennial


Description:
Lake/Pond: Hydrographic Category = Intermittent; Stage = High Water Elevation


Description:
Lake/Pond: Hydrographic Category = Intermittent; Stage = Date of Photography


Description:
Lake/Pond: Hydrographic Category = Perennial; Stage = Average Water Elevation


Description:
Lake/Pond: Hydrographic Category = Perennial; Stage = Normal Pool


Description:
Lake/Pond: Hydrographic Category = Perennial; Stage = Date of Photography


Description:
Lake/Pond: Hydrographic Category = Perennial; Stage = Spillway Elevation


Description:
Inundation Area: Inundation Control Status = Not Controlled


Description:
Inundation Area: Inundation Control Status = Controlled


Description:
Inundation Area: Inundation Control Status = Controlled; Stage = Flood Elevation


Description:
Pipeline: Pipeline Type = Aqueduct; Relationship to Surface = At or Near


Description:
Pipeline: Pipeline Type = Aqueduct; Relationship to Surface = Elevated


Description:
Pipeline: Pipeline Type = Aqueduct; Relationship to Surface = Underground


Description:
Pipeline: Pipeline Type = Aqueduct; Relationship to Surface = Underwater


Description:
Pipeline: Pipeline Type = General Case; Relationship to Surface = At or Near


Description:
Pipeline: Pipeline Type = General Case; Relationship to Surface = Elevated


Description:
Pipeline: Pipeline Type = General Case; Relationship to Surface = Underground


Description:
Pipeline: Pipeline Type = General Case; Relationship to Surface = Underwater


Description:
Pipeline: Pipeline Type = Penstock; Relationship to Surface = At or Near


Description:
Pipeline: Pipeline Type = Penstock; Relationship to Surface = Elevated


Description:
Pipeline: Pipeline Type = Penstock; Relationship to Surface = Underground


Description:
Pipeline: Pipeline Type = Penstock; Relationship to Surface = Underwater


Description:
Reservoir: Reservoir Type = Decorative Pool


Description:
Reservoir: Reservoir Type = Tailings Pond; Construction Material = Earthen


Description:
Reservoir: Reservoir Type = Tailings Pond


Description:
Reservoir: Reservoir Type = Swimming Pool


Description:
Reservoir: Reservoir Type = Cooling Pond


Description:
Reservoir: Reservoir Type = Filtration Pond


Description:
Reservoir: Reservoir Type = Settling Pond


Description:
Reservoir: Reservoir Type = Sewage Treatment Pond


Description:
Reservoir: Reservoir Type = Water Storage; Construction Material = Nonearthen


Description:
Reservoir: Reservoir Type = Water Storage; Construction Material = Earthen; Hydrographic Category = Intermittent


Description:
Reservoir: Reservoir Type = Water Storage; Construction Material = Earthen; Hydrographic Category = Perennial


Description:
Reservoir: Reservoir Type = Water Storage


Description:
Reservoir: Construction Material = Earthen


Description:
Reservoir: Construction Material = Nonearthen


Description:
Reservoir: Reservoir Type = Water Storage; Hydrographic Category = Perennial


Description:
Reservoir: Reservoir Type = Evaporator; Construction Material = Earthen


Description:
Rock: Relationship to Surface = Abovewater


Description:
Rock: Relationship to Surface = Underwater


Description:
Special Use Zone: Special Use Zone Type = Dump Site; Operational Status = Operational


Description:
Special Use Zone: Special Use Zone Type = Dump Site; Operational Status = Abandoned


Description:
Special Use Zone: Special Use Zone Type = Spoil Area; Operational Status = Operational


Description:
Special Use Zone: Special Use Zone Type = Spoil Area; Operational Status = Abandoned


Description:
Stream/River: Hydrographic Category = Intermittent


Description:
Stream/River: Hydrographic Category = Perennial


Description:
Sounding Datum Line: Positional Accuracy = Approximate


Description:
Sounding Datum Line: Positional Accuracy = Definite


Description:
Special Use Zone Limit: Positional Accuracy = Definite


Description:
Special Use Zone Limit: Positional Accuracy = Indefinite


# NHDMetadata

ProcessDescription:
Replaced branched and disjoint (disconnected) reaches with linear reaches in NHDFlowline.  This change occurred during the conversion to the geodatabase model.  Each NHDFlowline that was part of a branched or disjoint reach was assigned to a new reach.  The ComID of the NHDFlowline was unchanged   The change information from the old reach to the new reach was captured in the NHDReachCrossReference table.  Each new reach has M values assigned from 0 to 100.


ProcessDescription:
Merged and/or split area features (NHDWaterbody, NHDArea, region.wb, region.lm) and updated associated artificial path WBAreaComID (wb_com_id) values.  This change occurred during the conversion to the geodatabase model.  If adjacent or overlapping area features had identical classifications, including ReachCode where applicable, the features were merged.  If an area feature exceeded 100 sq. km. (25 sq. km. for canal/ditch, stream/river, or submerged stream) and crossed a subbasin boundary, the feature was split at the subbasin boundary.  If any sliver polygons of a size of less than 5 sq. km. adjoined the split features, the slivers were merged back into the larger area feature.  Merged or split area features were assigned a new ComID.


ProcessDescription:
Updated WBAreaComID (WB_COM_ID) on NHDFlowline (route.drain) where the associated area features were assigned new ComIDs from merge or split during the conversion to geodatabase.


ProcessDescription:
Edited NHDFlowline (route.drain) features to improve network connectivity and network flow.  This edit occurred during the conversion to the geodatabase model.  Features we snapped, spatially modified, flipped, added, or deleted to assure network integrity.  Also, some feature classification modifications occurred to convert artificial paths to coastlines.


ProcessDescription:
Create high-resolution NHD from USGS/WRD hydrography data.   This process started with the acquisition of two sources of  vectors provided by USGS NMD.  Existing 1:24,000-scale USGS  Digital Line Graph (DLG) data was available.  Feature code  attributes present in the DLG major and minor codes were used to  populate a temporary working coding scheme used by WRD.  For the  remaining quadrangle files, NMD provided unattributed vector data,  from scanned Mylar 1:24,000-scale hydrography separates.  The quads  were then converted into ArcInfo coverages and projected into  the Vermont State Plane coordinate system (VTSP, NAD83, meters).   Having the data in VTSP allowed for the draping of the vector  data with the State of Vermont's projected Digital Raster Graphic  (DRG) Images (source: USGS).  Quadrangle-based hydro coverages were  then edge-matched, where arcs 12 meters of each other along the  neatline were snapped together if the feature types were the same.   Next, the 12-digit Hydrologic Unit Code (HUC) boundary was  obtained from the State NRCS office.  The 12-digit HUC coverage  was manually interpreted from USGS, 1:24,000-scale, 7.5'  topographic maps.  The HUC boundary was used to break up the basin  into tiles based on the 12-digit HUCs which defined the basin  boundary.  Paneling the hydrography according to the 12-digit HUCs  allowed for systematic processing using a logical approach and  manageable format.  Where necessary, the HUC boundary was slightly  modified or the hydrography was corrected to completely include or  exclude features that incorrectly overlapped the HUC boundaries.   Substantial alterations to the HUC boundary were confirmed on the  topographic maps (DRGs).  Using available evidence or cartographic  judgement, lines called connectors were added to join features  that were deemed to have flow between each other.  Artificial  paths were digitized on-screen, manually, through 2-D waterbodies  using the waterbody geometry to digitize a centerline through the  features.  Next, arcs from the extracted coverage were grouped in  order to examine the connectivity of the dataset for flow  determination.  In some cases it was necessary to correct  digitizing errors.  Next, feature code attributes were assigned  for all arcs which did not already have coding assigned.  Feature  codes were assigned using WRD's coding scheme.  Next, arcs from  the extracted coverages were grouped in order to examine the  connectivity of the dataset for flow determination.  The  individual hydro files were then appended back together into one  single hydrography coverage.  All arcs fnode to tnode topology  were corrected to insure all arcs in the network pointed in a  downstream direction.  Last, all WRD feature codes were  transferred over into the NHD fcode scheme, and projected into  the NHD common projection (Albers, NAD83, meters).  Feature codes  (fcodes) were assigned to landmark, network, waterbody features  through a crosswalk that converts DLG-3 attributes to fcodes,  where an fcode is a five digit integer that encodes a set of  feature type characteristics.  Reach codes and associated  attributes were conflated from the 100K NHD data to the 24K  drainage network and 2-D waterbodies.  Several checks were  performed to validate the reach transfer process.  Any reach  codes that could not be maintained are tracked in the Reach  Cross Reference table.  New reaches that do not exist in the  100K data were defined according to reach delineation rules  (See http://nhd.usgs.gov/chapter1/index.html).  New waterbody  reaches were assigned to 2-D lake/pond and reservoir features  that do not exist in the 100K NHD.  New reaches were assigned  reach code values that are sequentially ordered to 2-D and then  1-D reaches.  New 24K reach codes are larger than any existing  100K reach code in the associated Catalog Unit.  Additional  Geographic Names that exist in the Geographic Names Information  System (GNIS) were added to reaches

AttributeAccuracyreport:
The accuracy of the attributes of the source Digital Line Graph  (DLG) data is estimated to be 98.5 percent.  One or more of the  following methods were used to test attribute accuracy:  manual  comparison of the source with hardcopy plots; symbolized display  of the digital line graph on an interactive computer graphic  system; selected attributes that could not be visually verified  on plots or on screen were interactively queried and verified on  screen.  In addition, software validated feature types and  characteristics against a master set of types and characteristics,  checked that combinations of types and characteristics were valid,  and that types and characteristics were valid for the delineation  of the feature.  Feature types, characteristics, and other  attributes conform to the Standards for National Hydrography Dataset  - High Resolution (USGS, 1999) as of the date they were loaded into  the database.  All names on the 1:24,000-scale reaches were  validated against a June 2002 extract from the Geographic Names  Information (GNIS) System.  The entry and identifier for the names  match those in GNIS.  The association of each name to reaches has  been interactively checked against the June 2002 GNIS extract,  however, operator error could in some cases apply a name to a wrong  reach.

LogicalConsistencyReport:
Points, nodes, lines, and areas conform to topological rules.   Lines intersect only at nodes, and all nodes anchor the ends  of lines.  Lines do not overshoot or undershoot other lines  where they are supposed to meet.  There are no duplicate lines.  Lines bound areas and lines identify the areas to the left and  right of the lines.  Gaps and overlaps among areas do not  exist.  All areas close.

CompletenessReport:
The completeness of the data reflects the published USGS  topographic quadrangle, usually supplemented by Digital  Orthophoto Quadrangles (DOQs).  Features found on the ground may  have been eliminated or generalized on the source map because  of scale and legibility constraints.  In general, streams longer  than one mile (approximately 1.6 kilometers) were collected.  Most streams that flow from a lake were collected regardless  of their length.  Only definite channels were collected so  not all swamp/marsh features have stream/rivers delineated  through them.  Lake/ponds 100 feet or greater in the shortest  axis were collected.  Note, however, that these general rules  were applied unevenly among maps during compilation.  Transport reaches are defined on nearly all features of type  stream/river, canal/ditch, artificial path, and connector.   Waterbody reaches are defined on all lake/pond features.  Detailed  capture conditions are provided for every feature type in the  Standards for National Hydrography Dataset - High Resolution  (USGS, 1999), available online through  http://mapping.usgs.gov/standards/.

HorizPositionalAccuracyReport:
Statements of horizontal positional accuracy are based on  accuracy statements made for U.S. Geological Survey topographic  quadrangle maps.  These maps were compiled to meet National Map  Accuracy Standards.  For horizontal accuracy, this standard is  met if at least 90 percent of points tested are within 0.02  inch (at map scale) of the true position.  Additional offsets  to positions may have been introduced where feature density is  high to improve the legibility of map symbols.  In addition, the  digitizing of maps is estimated to contain a horizontal  positional error of less than or equal to 0.003 inch standard  error (at map scale) in the two component directions relative  to the source maps.  Visual comparison between the map graphic  (including digital scans of the graphic) and plots or digital  displays of points, lines, and areas, is used as control to  assess the positional accuracy of digital data.  Digital map  elements along the adjoining edges of datasets are aligned if  they are within a 0.02 inch tolerance (at map scale).  Features  with like dimensionality (for example, features that all are  delineated with lines), with or without like characteristics,  that are within the tolerance are aligned by moving the  features equally to a common point.  Features outside the  tolerance are not moved; instead, a feature type of connector  is added to join the features.

VertPositionalAccuracyReport:
Statements of vertical positional accuracy for elevation of  water surfaces are based on accuracy statements made for  U.S. Geological Survey topographic quadrangle maps.  These  maps were compiled to meet National Map Accuracy Standards.   For vertical accuracy, this standard is met if at least 90  percent of well-defined points tested are within one-half  contour interval of the correct value.  Elevations of water  surface printed on the published map meet this standard;  the contour intervals of the maps vary.  These elevations  were transcribed into the digital data; the accuracy of  this transcription was checked by visual comparison between  the data and the map.

MetadataStandardName:
Content Standards For Digital Geospatial Metadata, ver.2

DataSetCredit:
U.S. Geological Survey in cooperation with U.S. Environmental  Protection Agency

Address:
Mid-Continent Mapping Center - 1400 Independence Road


ProcessDescription:
Create high-resolution NHD from USGS/WRD hydrography data.  This  process started with the acquisition of two sources of vectors  provided by USGS NMD.  Existing 1:24,000-scale USGS DLG data was  available.  Feature code attributes present in the DLG major and  minor codes were used to populate a temporary working coding  scheme used by WRD.  For the remaining quadrangle files, NMD  provided unattributed vector data from scanned Mylar 1:24,000- scale hydrography separates.  The quads were then converted into  ArcInfo coverages and projected into the Vermont State Plane  coordinate system (VTSP, NAD83, meters).  Having the data in VTSP  allowed for the draping of vector data with the State of Vermont's  projected Digital Raster Graphic (DRG) Images (source: USGS).   Quadrangle-based hydro coverages were edge-matched, where arcs 12  meters of each other along the neatline were snapped together if  the feature types were the same.  Next, the 12-digit Hydrologic  Unit Code (HUC) boundary was obtained from the State NRCS office.   The 12-digit HUC coverage was manually interpreted from USGS  1:24,000-scale 7.5' topographic maps.  The HUC boundary was used  to break up the basin into tiles based on HUCs defining the basin  boundary.  Paneling the hydrography according to 12-digit HUCs  allowed for systematic processing using a logical approach.   Where necessary, the HUC boundary was slightly modified or the  hydrography was corrected to completely include or exclude  features that incorrectly overlapped the HUC boundary.   Substantial alterations to the HUC boundary were confirmed on the  topographic maps (DRGs).  Using available evidence or cartographic  judgement, lines called connectors were added to join features  that were deemed to have flow between each other.  Artificial  paths were manually digitized on-screen through 2-D waterbodies,  using the waterbody geometry to digitize a centerline through the  features.  In some cases it was necessary to correct digitizing  errors.  Feature code attributes were assigned to all arcs which  did not already have coding.  Feature codes were assigned using  WRD's coding scheme.  Arcs from the extracted coverages were  grouped to examine the connectivity of the dataset for flow  determination.  The individual hydro files were then appended  together into a single hydrography coverage.  All arcs fnode to  tnode topology were corrected to ensure all arcs in the network  pointed in a downstream direction.  Last, all WRD feature codes  were transferred over into the NHD fcode scheme, and projected to  the common NHD projection (Albers, NAD83, meters).  Feature codes  (fcodes) were assigned to landmark, network, waterbody features  through a crosswalk that converts DLG-3 attributes to fcodes,  where an fcode is a five digit integer that encodes a set of  feature type characteristics.  Reach codes and associated  attributes were conflated from the 100K NHD data to the 24K  drainage network and 2-D waterbodies.  Several checks were  performed to validate the reach transfer process.  Any reach  codes that could not be maintained are tracked in the Reach Cross  Reference table.  New reaches that do not exist in the 100K data  were defined according to reach delineation rules (See http:// nhd.usgs.gov/chapter1/index.html).  New waterbody reaches were  assigned to 2-D lake/pond and reservoir features that do not exist  in the 100K NHD.  New reaches were assigned reach code values that  are sequentially ordered to 2-D and then 1-D reaches.  New 24K  reach codes are larger than any existing 100K reach code in the  associated subbasin.  Additional geographic names that exist in  the Geographic Names Information System (GNIS) were added to  reaches in the 24K dataset.  Names for the 24K drainage network  were interactively transferred from the vector GNIS coverage.   Additional GNIS names for point and waterbody features were also  added.

AttributeAccuracyreport:
The accuracy of the attributes of the source Digital Line Graph  (DLG) data is estimated to be 98.5 percent.  One or more of the  following methods were used to test attribute accuracy:  manual  comparison of the source with hardcopy plots; symbolized display  of the digital line graph on an interactive computer graphic  system; selected attributes that could not be visually verified  on plots or on screen were interactively queried and verified on  screen.  In addition, software validated feature types and  characteristics against a master set of types and characteristics,  checked that combinations of types and characteristics were valid,  and that types and characteristics were valid for the delineation  of the feature.  Feature types, characteristics, and other  attributes conform to the Standards for National Hydrography Dataset  - High Resolution (USGS, 1999) as of the date they were loaded into  the database.  All names on the 1:24,000-scale reaches were  validated against a June 2002 extract from the Geographic Names  Information (GNIS) System.  The entry and identifier for the names  match those in GNIS.  The association of each name to reaches has  been interactively checked against the GNIS extract, however,  operator error could in some cases apply a name to a wrong reach.

MetadataStandardName:
FGDC Content Standards For Digital Geospatial Metadata, ver.2


ProcessDescription:
Create high-resolution NHD from USGS DLG data. DLG files were  converted to ArcInfo coverages and projected to the New  Hampshire State Plane coordinate system (NHSP NAD83 Feet).  Having the data in NHSP allowed for the draping of the vector  data with the State of New Hampshire's projected Digital  Raster Graphic Images (DRGs, source: USGS), when needed for  feature verification/connection. The DLG coverages were  edgematched using a 40 foot snapping tolerance.  Features  outside the tolerance were not moved; instead, a feature of  type connector was added to join the features. DLG feature  coding was visually verified using hardcopy plots. Coverages  were then paneled into one coverage and arcs within 40 feet  of each other along the neatline were again snapped together  if the feature types were the same.  Next, the 11-digit  Hydrologic Unit Code (HUC) boundary was used to extract  features from the paneled coverage that fell within the  boundary. Next, arcs from the extracted coverage were grouped  in order to examine the connectivity of the data set for  flow determination. In some cases it was necessary to correct  digitizing errors.  Using contour lines from the New Hampshire  DRGs, lines called connectors were added to join features that  were deemed to have flow between each other.  All arcs were  directed downstream and the nodes were prepared to help create artificial paths through 2-D waterbodies and complete the flow through the hydrography network.  The artificial path coverage was combined with the single line stream network to create the drainage network.  The drainage network was grouped again,  and each group was directed downstream.  The data was then  appended to conform to the 8-digit CU boundaries.  Feature codes  (fcodes)were assigned to network and waterbody features through  a crosswalk that converts DLG-3 attributes to fcodes, where an  fcode is a five digit integer that encodes a set of feature type  characteristics.  Reach codes and associated attributes were  conflated from the 100K NHD data to the 24K drainage network and  2-D waterbodies. Several checks were performed to validate the  reach transfer process. Any reach codes that could not be  maintained are tracked in the Reach Cross Reference table. New  reaches that do not exist in the 100K data were defined  according to reach delineation rules  (See http://nhd.usgs.gov/chapter1/index.html).   New waterbody reaches were assigned to 2-D lake/pond and  reservoir features that do not exist in the 100K NHD.  New  reaches were assigned reach code values that are sequentially  ordered to 2-D and then 1-D reaches. New 24K reach codes are  larger than any existing 100K reach code in the associated  Catalog Unit. Additional Geographic Names that exist in the  Geographic Names Information System (GNIS) were added to reaches  in the 24K dataset. Names for the 24K drainage network were  interactively transferred from the vector GNIS coverage.  Additional GNIS names for waterbody features were also added.

AttributeAccuracyreport:
The accuracy of the attributes of the source Digital Line  Graph data is estimated to be 98.5 percent. One or more of  the following methods were used to test attribute accuracy:  manual comparison of the source with hardcopy plots;  symbolized display of the digital line graph on an  interactive computer graphic system; selected attributes  that could not be visually verified on plots or on screen  were interactively queried and verified on screen. In  addition, software validated feature types and  characteristics against a master set of types and  characteristics,checked that combinations of types and  characteristics were valid, and that types and  characteristics were valid for the delineation of the  feature. Feature types, characteristics, and other  attributes conform to the Standards for National  Hydrography Dataset - High Resolution (USGS, 1999) as of  the date they were loaded into the database. All names  on the 1:24,000-scale reaches were validated against a  April 1999 extract from the Geographic Names Information  System. The entry and identifier for the names match those  in the Geographic Names Information System. The association  of each name to reaches has been interactively checked  against the April 1999 Geographic Names Information System  names extract, however, operator error could in some cases  apply a name to a wrong reach.

LogicalConsistencyReport:
Points, nodes, lines, and areas conform to topological rules.   Lines intersect only at nodes, and all nodes anchor the ends  of lines.  Lines do not overshoot or undershoot other lines  where they are supposed to meet. There are no duplicate lines.  Lines bound areas and lines identify the areas to the left and  right of the lines.  Gaps and overlaps among areas do not  exist.  All areas close.

CompletenessReport:
The completeness of the data reflects the published USGS  topographic quadrangle usually, supplemented by Digital  Orthophoto Quadrangles(DOQ's). Features found on the ground may  have been eliminated or generalized on the source map because  of scale and legibility constraints.  In general, streams longer  than one mile (approximately 1.6 kilometers) were collected.  Most streams that flow from a lake were collected regardless  of their length.  Only definite channels were collected so  not all swamp/marsh features have stream/rivers delineated  through them.  Lake/ponds 100 feet or greater in the shortest  axis were collected.  Note, however, that these general rules  were applied unevenly among maps during compilation.  Transport reaches are defined on nearly all features of type  stream/river, canal/ditch, artificial path, and connector.   Waterbody reaches are defined on all lake/pond features. Detailed  capture conditions are provided for every feature type in the  Standards for National Hydrography Dataset - High Resolution  (USGS, 1999), available online through  http://mapping.usgs.gov/standards/.

HorizPositionalAccuracyReport:
Statements of horizontal positional accuracy are based on  accuracy statements made for U.S. Geological Survey topographic  quadrangle maps. These maps were compiled to meet National Map  Accuracy Standards. For horizontal accuracy, this standard is  met if at least 90 percent of points tested are within 0.02  inch (at map scale) of the true position.  Additional offsets  to positions may have been introduced where feature density is  high to improve the legibility of map symbols.In addition, the  digitizing of maps is estimated to contain a horizontal  positional error of less than or equal to 0.003 inch standard  error(at map scale) in the two component directions relative  to the source maps.  Visual comparison between the map graphic  (including digital scans of the graphic) and plots or digital  displays of points, lines, and areas, is used as control to  assess the positional accuracy of digital data. Digital map  elements along the adjoining edges of data sets are aligned if  they are within a 0.02 inch tolerance (at map scale). Features  with like dimensionality (for example, features that all are  delineated with lines), with or without like characteristics,  that are within the tolerance are aligned by moving the  features equally to a common point. Features outside the  tolerance are not moved; instead, a feature of type connector  is added to join the features.

VertPositionalAccuracyReport:
Statements of vertical positional accuracy for elevation of  water surfaces are  based on accuracy statements made for  U.S. Geological Survey topographicquadrangle maps.  These  maps were compiled to meet National Map Accuracy Standards.   For vertical accuracy, this standard is met if at least 90  percent of well-defined points tested are within one-half  contour interval of the correct value.  Elevations of water  surface printed on the published map meet this standard;  the contour intervals of the maps vary. These elevations  were transcribed into the digital data; the accuracy of  this transcription was checked by visual comparison between  the data and the map.

MetadataStandardName:
FGDC Content Standards For Digital Geospatial Metadata

DataSetCredit:
U.S. Geological Survey in cooperation with U. S. Environmental Protection Agency, Complex Systems Research Center at the University of New Hampshire, and New Hampshire Department of Environmental Services.


# NHDSourceCitation

Originator:
U.S. Geological Survey in cooperation with U.S. Environmental  Protection Agency

SourceContribution:
Reach codes and flow direction attributes


Title:
Geographic Names Information System Oracle Database

SourceContribution:
Names for reaches and areal water bodies


Originator:
Natural Resources Conservation Service (NRCS) in cooperation with  University of Vermont Spatial Analysis Lab (UVM)


SourceCurrentnessReference:
Date the revision process step was completed


Originator:
Natural Resources Conservation Service (NRCS) in cooperation  with University of Vermont Spatial Analysis Lab (UVM)


Originator:
U.S. Geological Survey in cooperation with the  U.S. Environmental Protection Agency

SourceContribution:
Reach codes and flow direction attributes.


SourceContribution:
Names for reaches and areal water bodies.


Originator:
U.S. Geological Survey (USGS), in cooperation with the Natural Resources Conservation Service (NRCS),  and the New Hampshire Department of Environmental Services.


