This data set is a complete digital hydrologic unit boundary layer to the Subwatershed (12-digit) 6th level for the State of Florida. This data set consists of geo-referenced digital data and associated attributes created in accordance with the "FGDC Proposal, Version 1.0 - Federal Standards For Delineation of Hydrologic Unit Boundaries 3/01/02"(http://www.ftw.nrcs.usda.gov/huc_data.html). Polygons are attributed with hydrologic unit codes for 4th level sub-basins, 5th level watersheds, 6th level subwatersheds, name, size, downstream hydrologic unit, type of watershed, non-contributing areas and flow modification. Arcs are attributed with the highest hydrologic unit code for each watershed, linesource and a metadata reference file.
The NHD is a national framework for assigning reach addresses to water-related entities, such as industrial discharges, drinking water supplies, fish habitat areas, wild and scenic rivers. Reach addresses establish the locations of these entities relative to one another within the NHD surface water drainage network, much like addresses on streets. Once linked to the NHD by their reach addresses, the upstream/downstream relationships of these water-related entities--and any associated information about them--can be analyzed using software tools ranging from spreadsheets to geographic information systems (GIS). GIS can also be used to combine NHD-based network analysis with other data layers, such as soils, land use and population, to help understand and display their respective effects upon one another. Furthermore, because the NHD provides a nationally consistent framework for addressing and analysis, water-related information linked to reach addresses by one organization (national, state, local) can be shared with other organizations and easily integrated into many different types of applications to the benefit of all.
publication date
None. Acknowledgment of the originating agencies would be appreciated in products derived from these data.
507 National Center
In addition to the address above there are other ESIC offices throughout the country. A full list of these offices is at URL: http://mapping.usgs.gov/esic/esic_index.html
507 National Center
USGS, FDEP, Division of Environmental Assessment and Restoration
GeoPlan relied on the integrity of the attribute information within the original data.
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.
The completeness of the data reflects the content of the sources, which most often are the published USGS topographic quadrangle and/or the USDA Forest Service Primary Base Series (PBS) map. The USGS topographic quadrangle is 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 having an area greater than 6 acres were collected. Note, however, that these general rules were applied unevenly among maps during compilation. Reaches codes are defined on all features of type stream/river, canal/ditch, artificial path, coastline, and connector. Waterbody reach codes are defined on all lake/pond and most reservoir features. Names were applied from the GNIS database. Detailed capture conditions are provided for every feature type in the Standards for National Hydrography Dataset available online through http://mapping.usgs.gov/standards/. This statement is generally true for the most common sources of NHD data. Other sources and methods may have been used to create or update NHD data. In some cases, additional information may be found in the NHDMetadata table.
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. This statement is generally true for the most common sources of NHD data. Other sources and methods may have been used to create or update NHD data. In some cases, additional information may be found in the NHDMetadata table.
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. This statement is generally true for the most common sources of NHD data. Other sources and methods may have been used to create or update NHD data. In some cases, additional information may be found in the NHDMetadata table.
Spatial and Attribute Information
In June 2013, the existing Florida NHD100K and NHD 24K as downloaded April 10, 2013 from the USGS NHD, Hydrologic Units, GNIS alternate names and relationships were combined into one file geodatabase for public distribution and use. Notable changes to the 24K NHD database since the previous download in December 2012 are as follows: Full photo revision to Lake Okeechobee (03090201), Hillsborough (03100205) and Alafia (03100204) sub basins; Full photo revision to portions of Peace (03100101), Withlacoochee (03100208), Choctawatchee Bay (03140102), miscellaneous updates in Big Cypress Swamp (03090204) and Everglades (03090202); miscellaneous edits/additions of stream gages, dams and other point event features by USGS. The database includes a network using the NHD24 NHDFlowline featureclass. The Utility Network Analyst tool can be used to trace routes through the network, however please note that if you set the results of the trace as selected features and zoom to selected, you may zoom to a scale that is outside the NHD24 dependency settings.
Data updated in ArcSDE/DataMiner and MapDirect. Metadata updated.
In November 2013, the existing Florida NHD100K and NHD 24K as downloaded November 12, 2013 from the USGS NHD, Hydrologic Units, GNIS alternate names and relationships were combined into one file geodatabase for public distribution and use. Notable edits in the 24K NHD database since the previous download in April 2012 were in the following subbasins: Withlacoochee (03100208), Peace (03100101), Upper St. Johns (03080101), Kissimmee (03090101), Florida Southeast Coast (03090206), Choctawhatchee Bay (03140102), Lower Choctawhatchee (03140203) and assorted network improvements made by USGS staff.
Data updated in ArcSDE/DataMiner and MapDirect. Metadata updated.
In May 2014, the existing Florida NHD100K and NHD 24K as downloaded May 12, 2014 from the USGS NHD, Hydrologic Units, GNIS alternate names and relationships were combined into one file geodatabase for public distribution and use. Notable changes to the 24K NHD database since the previous download in November 2013 are as follows: Aerial imagery revision to priority WBIDs ( Waterbody IDs provided by DEP Water Assessment Section), other WBIDs and network improvements by USGS to Tampa Bay (03100206), Crystal- Pithlachascotee (03100207), Withlacoochee (03110203), Charlotte Harbor (03100103), St. Andrew-St. Joseph Bays (03140101), Vero Beach (03080203), Everglades (03090202), Blackwater (03140104), Manatee (03100202), Econfina- Steinhatchee (03110102), Caloosahatchee (03090205), Perdido (03140106), Florida Southeast Coast (03090206), Lake Okeechobee (03090201), Cumberland- St. Simons (03070203), Santa Fe (03110206), Alapaha (03110202), Aucilla (03110103), Lower Ochlockonee (03120003), Cape Canaveral (03080202), Nassau (03070205), Upper Suwannee (03110201), Myakka (03100102), Chipola (03130012), Pensacola Bay (03140105), Upper St. Johns (03080101), Lower St. Johns (03080103), Oklawaha (03080102), Little Manatee (03100203), Waccasassa (03110101), Apalachee Bay-St. Marks (03120001), Western Okeechobee Inflow (03090103), Northern Okeechobee Inflow (03090102), St. Marys (03070204), Daytona-St. Augustine (03080201), Kissimmee (03090101), Lower Suwannee (03110205), Big Cypress Swamp (03090204), Peace (03100101), Yellow (03140103), . The database includes a network using the NHD24 NHDFlowline featureclass. The Utility Network Analyst tool can be used to trace routes through the network, however please note that if you set the results of the trace as selected features and zoom to selected, you may zoom to a scale that is outside the NHD24 dependency settings.
The processes used to create and maintain high-resolution NHD data can be found in the table called "NHDMetadata". Because NHD data can be downloaded using several user-defined areas, the process descriptions can vary for each download. The NHDMetadata table contains a list of all the process descriptions that apply to a particular download. These process descriptions are linked using the DuuID to the NHDFeatureToMetadata table which contains the com_ids of all the features within the download. In addition, another table, the NHDSourceCitation, can also be linked through the DuuID to determine the sources used to create or update NHD data.
In October 2014, the existing Florida NHD100K and NHD 24K as downloaded October 22, 2014 from the USGS NHD, Hydrologic Units, GNIS alternate names and relationships were combined into one file geodatabase for public distribution and use. Notable changes to the 24K NHD database since the previous download in May 2014 are as follows: Geographic Information Names System (GNIS) specific updates, aerial imagery based updates to prioritized Florida DEP Waterbody IDs (WBIDs), and/or additional aerial imagery based updates to St. Marys (3070204), Nassau (3070205), Upper St. Johns (3080101), Lower St. Johns (3080103), Daytona-St. Augustine (3080201), Cape Canaveral (3080202), Vero Beach (3080203), Kissimmee (3090101), Big Cypress Swamp (3090204), Caloosahatchee (3090205), Florida Southeast Coast (3090206), Crystal-Pithlachascotee (3100207), Econfina-Steinhatchee (3110102), Aucilla (3110103), Apalachee Bay-St. Marks (3120001), Lower Ochlockonee (3120003), Apalachicola (3130011), New (3130013), Apalachicola Bay (3130014), St. Andrew-St. Josephs Bays (3140101), Choctawhatchee Bay (3140102), Yellow (3140103), Blackwater (3140104), Pensacola Bay (3140105), Perdido (3140106), Perdido Bay (3140107), Lower Choctawhatchee (3140203) and Escambia (3140305) sub basins.
An October 22, 2014 copy of the Florida NHD was obtained from the USGS for purposes of updating the Florida Dept. of Environmental Protection Agencies SDE data. For this release, a new field called ?Parent_Feature?was added to the NHDFlowline featureclass. Using Field Calculator, the ?Parent_Feature? attribute for flowline features with FType not equal to Artificial Path were updated to the FType. For artificial path flowlines, a series of analyses using the relationship between the WBArea_Permanent_identifier field and the Permanent_identifier fields of each of the NHDArea and NHDWaterbody featureclasses facilitated the update of the Parent_Feature attribute. Several ?select by location? analyses further provided updated to the ?Parent_Feature.? Several hundred artificial paths remained after exhausting multiple analysis options and were ultimately individually inspected to see the relationship between the artificial path and the feature for which it was within.
Changes in the October 2014 download of the Florida NHD include new and updated NHD Point Events. These EventTypes follow the same format as the FCodes in the other featureclasses. Added detail has been incorporated for stream gages. Stream gages are now listed as being active (with continuous or partial data) or inactive. Dams are still included, but like the others, the code has changed. Past layer files referencing the NHDPointEvents featureclass will need updated symbology to link to the new codes. The layer file used on the FDEP DataMiner application has been updated to reflect the updates. New codes are as follows: 57001 - Stream Gage, Active, Continuous data; 57002 - Stream Gage, Active, Partial data; 57003 - Stream Gage, Inactive; 57100 - Dam.
Data updated in the GIS library
2600 Blair Stone Rd MS 6520
In May 2015, the Florida NHD 100K (as of March 25, 2015) and NHD 24K (as of March 17, 2015) including Watershed Boundary Dataset Hydrologic Units, GNIS alternate names and relationships were combined into one file geodatabase for public distribution and use. Notable changes to the 24K NHD database since the previous download in October 2014 are as follows: Geographic Information Names System (GNIS) specific updates in St. Marys (03070204), Nassau (03070205), Lower St. Johns (03080103), Caloosahatchee (03090205), Myakka (03100102), Sarasota Bay (03100201), Manatee (03100202), Little Manatee (03100203), Hillsborough (03100205), Withlacoochee (03100208), Waccasassa (03110101), Upper Suwannee (03110201), Alapaha (03110202), Withlacoochee (03110203), Lower Suwannee (03110205), Santa Fe (03110206), Lower Chattahoochee (03130004), Chipola (03130012), St. Andrew-St. Joseph Bays (03140101) & Pea (03140202) subbasins; Aerial Imagery Revision in Upper St. Johns (03080101), Western Okeechobee Inflow (03090103), Lake Okeechobee (03090201), Everglades (03090202), Florida Bay-Florida Keys (03090203), Big Cypress Swamp (03090204), Florida Southeast Coast (03090206), Alafia (03100204), Aucilla (03110103), Lower Suwannee (03110205), Blackwater (03140104), Pensacola Bay (03140105) & Perdido (03140106) subbasins. The database includes a network using the NHD24 NHDFlowline featureclass. The Utility Network Analyst tool can be used to trace connected features through the network, however please note that if you set the results of the trace as selected features and zoom to selected, you may zoom to and be limited to the maximum scale set the NHD24K and NHDFlowline scale dependency settings. If this happens, to see the full set of selected features, change both the layer and group settings to ?Show layer at all scales?, unclick the NHD 100K and Major NHD 100K group layers, and then zoom to the selected features again. Additionally, a new field in the 24K NHD Flowline featureclass has been added to support the analysis of Flowline features. The ? Parent_Feature? identifies the feature type of the flowline in all cases except for Artificial Paths. For Artificial paths, the feature type of the polygon feature it resides in has been used.
Data updated in the GIS library.
2600 Blair Stone Rd MS 6520
In December 2015, the Florida NHD 100K (as of March 25, 2015) and NHD 24K (as of October 22, 2015) including Watershed Boundary Dataset Hydrologic Units, GNIS alternate names and relationships were combined into one file geodatabase for public distribution and use. Notable changes to the 24K NHD database since the previous download in October 2014 are as follows: Edits performed by the Florida stewardship team in Alafia (03100204), Big Cypress Swamp (03090204), Blackwater (03140104), Crystal-Pithlachascotee (03100207), Econfina- Steinhatchee (03110102), Everglades (03090202), Florida Bay-Florida Keys (03090203), Lake Okeechobee (03090201), Lower Choctawhatchee (03140203), Lower Ochlockonee (03120003), Lower Suwannee (03110205), Pensacola Bay (03140105), St. Andrew-St. Joseph Bays (03140101), St. Marys (03070204), and Upper St. Johns (03080101) subbasins; Edits performed by USGS for attribute updates, connectivity checks and updating m-values in Alafia (03100204), Alapaha (03110202), Apalachee Bay-St. Marks (03120001), Apalachicola (03130011), Aucilla (03110103), Big Cypress Swamp (03090204), Blackwater (03140104), Caloosahatchee (03090205), Chipola (03130012), Choctawhatchee Bay (03140102), Daytona-St. Augustine (03080201), Escambia (03140305), Florida Southeast Coast (03090206), Kissimmee (03090101), Lake Okeechobee (03090201), Little Manatee (03100203), Lower Choctawhatchee (03140203), Lower Conecuh (03140304), Lower Ochlockonee (03120003), Lower St. Johns (03080103), Lower Suwannee (03110205), New (03130013), Oklawaha (03080102), Pensacola Bay (03140105), and Perdido (03140106) subbasins. The database includes a network using the NHD24 NHDFlowline featureclass. The Utility Network Analyst tool can be used to trace routes through the network, however please note that if you set the results of the trace as selected features and zoom to selected, you may zoom to a scale that is outside the NHD24 dependency settings. Additionally, a new field in the 24K NHD Flowline featureclass has been added to support the analysis of Flowline features. The ?Parent_Feature? identifies the feature type of the flowline in all cases except for Artificial Paths. For Artificial paths, the feature type of the polygon feature it resides in has been used. See process step for additional information. It was realized that the US Board on Geographic Names doesn't recognize Atlantic Ocean along the western side of the state. The Florida stewardship team was in the process of removing these polygons but not all the edits made it into this original version of the NHD. After downloading the October 22, 2015 version of the NHD, the remaining Atlantic Ocean polygons in the Gulf were manually removed and currently match the federal database. The NHD editing process officially removed the polygons from the national database using the USGS tools in November.
2600 Blair Stone Rd
Data updated in the GIS library.
2600 Blair Stone Rd MS 6520
Added NOAA- NFHAP Estuarine Zones layer in the NHD layer published in DataMiner.
2600 Blair Stone Rd MS 6520
In April 2016, the existing Florida NHD100K and NHD 24K as downloaded February 25, 2016 from the USGS NHD, Hydrologic Units, GNIS alternate names and relationships were combined into one file geodatabase for public distribution and use. Notable edits in the 24K NHD database since the previous download were in the following subbasins: Apalachee Bay-St. Marks, Apalachicola Bay, Big Cypress Swamp, Charlotte Harbor, Choctawhatchee Bay, Escambia, Everglades, Kissimmee, Lower Choctawhatchee, Lower Suwannee, Myakka, St. Andrew-St. Joseph Bays, Upper St. Johns, and Western Okeechobee Inflow and assorted network improvements made by USGS staff. The database includes a network using the NHD24 NHDFlowline featureclass. The Utility Network Analyst tool can be used to trace routes through the network, however please note that if you set the results of the trace as selected features and zoom to selected, you may zoom to a scale that is outside the NHD24 dependency settings.
2600 Blair Stone Rd
Data updated in SDE and DataMiner. Metadata updated.
2600 Blair Stone Rd MS 6520
In October 2016, the existing Florida NHD100K and NHD 24K as downloaded September 5, 2016 from the USGS NHD, Hydrologic Units, GNIS alternate names and relationships were combined into one file geodatabase for public distribution and use. Notable edits in the 24K NHD database since the previous download were in the following subbasins: Big Cypress Swamp, Caloosahatchee, Cape Canaveral, Daytona-St. Augustine, Econfina-Steinhatchee, Everglades, Kissimmee, Lake Okeechobee, Lower Ochlockonee, New, St. Andrew-St. Joseph Bays, Upper St. Johns, Oklawaha, Vero Beach and includes assorted network improvements made by USGS staff. The database includes a network using the NHD24 NHDFlowline featureclass. The Utility Network Analyst tool can be used to trace routes through the network, however please note that if you set the results of the trace as selected features and zoom to selected, you may zoom to a scale that is outside the NHD24 dependency settings.
2600 Blair Stone Rd
Revised data obtained from DEAR as part of the biannual NHD update and updated the same in the GIS library. Metadata updated.
2600 Blair Stone Rd MS 6520
In January 2017, the existing Florida NHD100K and NHD 24K as downloaded January 17, 2017 from the USGS NHD, Hydrologic Units, GNIS alternate names (from December 1, 2016) and relationships were combined into one file geodatabase for public distribution and use. Notable edits in the 24K NHD database since the previous download were in the following subbasins: Florida Southeast Coast (03090206), Apalachicola (03130011), St. Andrew-St. Joseph Bays (03140101) and assorted network improvements made by USGS staff in St. Andrew-St. Joseph Bays (03140101). The database includes a network using the NHD24 NHDFlowline featureclass. The Utility Network Analyst tool can be used to trace routes through the network, however please note that if you set the results of the trace as selected features and zoom to selected, you may zoom to a scale that is outside the NHD24 dependency settings.Relationship classes have been created to identify additional names that features may be known by through the Variant Names table. Relationship classes have also been created to facilitate the identification of which waterbody or area a flowline traverses through based on the WBAreaPermanent_ID field.
2600 Blair Stone Rd
Updated data obtained from DEAR and updated the same in the GIS library.
2600 Blair Stone Rd MS 6520
In June 2017, the existing Florida NHD100K and NHD 24K as downloaded May 1, 2017 from the USGS NHD, Hydrologic Units, GNIS alternate names (from June 1, 2017) and relationships were combined into one file geodatabase for public distribution and use. Notable edits in the 24K NHD database since the previous download were in the following subbasins: Florida Southeast Coast (03090206), Withlacoochee (0300208), Little Manatee (03100203), Everglades (03090202), and Econfina-Steinhatchee (03110102). In preperation for the NHDPlusHR, 39 basins received minor edits to fix USGS Severity 1 and 3 errors. The database includes a network using the NHD24 NHDFlowline featureclass. The Utility Network Analyst tool can be used to trace routes through the network, however please note that if you set the results of the trace as selected features and zoom to selected, you may zoom to a scale that is outside the NHD24 dependency settings.Relationship classes have been created to identify additional names that features may be known by through the Variant Names table. Relationship classes have also been created to facilitate the identification of which waterbody or area a flowline traverses through based on the WBAreaPermanent_ID field.
GeoPlan Center downloaded the NHD GeoDatabase from the Florida Department of Environmental Protection in March 2018. The data was exported to shapefile and defined with the FGDL Albers projection file. This data was originally produced by U.S. Geological Survey in cooperation with U.S. Environmental Protection Agency, USDA Forest Service, and other Federal, State and local partners. The Florida Data Stewards (FDEP) then update the data. After exporting GDB feature classes to shapefile using ArcGIS 10.3.1, the NONCONTRIBUTINACRES renamed to NONCON_AC NONCONTRIBUTINGSQKM renamed to NONCON_KM HYTYPE_DSC added based on HUTYPE domain text values Upcased all fields DESCRIPT field added based on NAME field FGDLAQDATE added based on date downloaded from source Renamed GDB feature class from WBDHU12 to nhdwbd_huc12.shp Metadata was derived using instructions from here: http://nhd.usgs.gov/wbd_metadata.html Attribute definitions were taken from here: https://pubs.usgs.gov/tm/11/a3/pdf/tm11-a3.pdf
Dataset copied.
Internal feature number.
ESRI
Feature geometry.
Esri
(short for The National Map Identification) is a unique 40-character field that identifies each element in the database exclusively. TNMID is an automatically assigned code that stays with each element. When an element is updated or changed, TNMID links the element to the metadata record and documents the change. TNMID is also used to maintain relationship classes in the normalized data model. When an element is deleted or split, TNMID stays with the original element and is not used again. When an element is split, new permanent identifiers are assigned to the resultant parts.
U.S. Geological Survey, Earth Science Information Center
Unique identifier that links the element to the metadata tables. This ID is generated and assigned automatically by the database and remains with the object permanently.
U.S. Geological Survey, Earth Science Information Center
A space provided for a brief description of the type of base data used to update or change the current WBD. The WBD In-State Steward completes this field as part of the metadata form
U.S. Geological Survey, Earth Science Information Center
The description of the agency that created the base data used to improve the WBD. The WBD In-State Steward completes this field as part of the metadata form.
U.S. Geological Survey, Earth Science Information Center
Like TNMID, SourceFeatureID is a long, unique code. This code identifies the parent of the feature if the feature is the result of a split or merge, and it is automatically generated and assigned
U.S. Geological Survey, Earth Science Information Center
Represents the date when the data were loaded into the official USGS WBD ArcSDE database. The field is the effective date for all feature edits, and it is automatically generated.
U.S. Geological Survey, Earth Science Information Center
Preassigned numeric field that uses a unique number to relate the name of the hydrologic unit to the GNIS names database. This field is automatically generated in the database.
U.S. Geological Survey, Earth Science Information Center
Common to all polygon feature classes and is calculated at the 12-digit hydrologic unit from the intrinsic area value maintained by the GIS software; therefore, acreage values may vary from user calculations, depending on the projection of the data. North American Albers Equal Area Conic, North American Datum 1983 is the required projection to use for calculation. If the units of the area field are stored in square meters, then use the conversion factor 0.0002471. For example, 40,469,446 square meters multiplied by 0.0002471 = 10,000 acres.
U.S. Geological Survey, Earth Science Information Center
Calculated at the 12-digit hydrologic unit from the intrinsic area value maintained by the GIS software; therefore, the square kilometer values may vary from user calculations, depending on the projection of the data. North American Albers Equal Area Conic, North American Datum 1983 is the default projection.
U.S. Geological Survey, Earth Science Information Center
The States or outlying area attribute identifies the State(s) or outlying areas that the hydrologic unit falls within or touches. The U.S. Census Bureau 1:100,000-scale State layer will be used to establish State boundaries in the derivation process. The two-letter U.S. Postal Service State abbreviation is assigned. If a hydrologic unit crosses into Canada, the two- letter Canada Post abbreviation for the Province is used. If a unit crosses into Mexico, the MX designation is used. If more than one abbreviation is used, they are separated by commas, without spaces, and are sorted in alphabetical order. This field is populated by the In-State Steward at the 12-digit hydrologic unit
U.S. Geological Survey, Earth Science Information Center
The HUC12 field is a unique 12-digit hydrologic unit code.
U.S. Geological Survey, Earth Science Information Center
The 16-digit hydrologic unit name refers to the GNIS name for the geographic area in which the hydrologic unit is located
U.S. Geological Survey, Earth Science Information Center
The 10-digit hydrologic unit type attribute is the single- letter abbreviation for Watershed type from the list of official names provided below. Use the single type that most closely describes the 10-digit hydrologic unit (see coastal examples in fig. 10).
U.S. Geological Survey, Earth Science Information Center
Standard hydrologic unit An area with drainage flowing to a single outlet point, excluding noncontributing areas. Some examples include true, classic, composite, and remnant hydrologic units (section 3.5.1).
Closed Basin hydrologic unit A drainage area where all surface flow is internal (100 percent noncontributing); no overland flow leaves the hydrologic unit through the outlet point (section 3.5.2).
Frontal hydrologic unit An area along the coastline of a lake, ocean, bay, etc., that has more than one outlet. These hydrologic units are predominantly land with some water areas at or near the outlet(s) (section 3.5.2).
Multiple Outlet hydrologic unit An area that has more than one natural outlet; for example, an outlet located on a stream with multiple channels. This does not include frontal or water hydrologic units, hydrologic units with artificial interbasin transfers, drainage outlets through karst or groundwater flow, or outlets that cross a stream with an island. This code should be used only in rare instances.
Water hydrologic unit An area that is predominantly water with adjacent land areas; for example, a lake, estuary, or harbor (section 3.6).
Island hydrologic unit An area that is one or more islands and adjacent water (section 3.6.4).
The 10-digit hydrologic unit modification attribute is a two-character, uppercase abbreviation(s) for either (1) the type of modification to natural overland flow that alters the natural delineation of a 10-digit hydrologic unit or (2) the special conditions GF-groundwater flow, GL-glacier, IF-ice field, KA- karst, and NC-noncontributing area. The value of the HUMod field helps to indicate where the modification to the 10-digit hydrologic unit is located. If more than one abbreviation is used, then separate them by commas without spaces and list them from most to least predominant. There are future plans to derive this field at the 10-digit unit from the information on the HUMod from the lines and the HUMod at the 12-digit unit upon check in. Once that process is in place the content will be overwritten. Previous versions of this guideline did not provide the same number of modification choices check metadata or contact the principal WBD In-State Steward for more information.
U.S. Geological Survey, Earth Science Information Center
Artificial Waterway A canal, ditch, or drain used to transport surface water that alters the natural flow out of the hydrologic unit. (The previously included designations AD Aqueduct, DD Drainage Ditch, GC General Canal/Ditch, ID Irrigation Ditch, IT Interbasin Transfer, SD Stormwater Ditch, SC Stormwater Canal, and BC Barge Canal have now been grouped into this designation). Withdrawing and receiving hydrologic units should carry this designation, as well as all hydrologic units in which the flow is altered by an artificial waterway.
Groundwater Flow A special condition, usually in locations with sandy soil, where most of the runoff in a hydrologic unit drains underground.
Karst A special condition where a hydrologic unit is within an area of, or includes an area of, geologic formations of irregular limestone deposits with sinks, underground streams, or caverns.
Mining Activity Substatial topographic modification of a hydrologic unit by surface mining; alters the natural flow out of the hydrologic unit.
Noncontributing Area A naturally formed area that does not contribute surface water runoff to a hydrologic unit outlet under normal conditions; for example, a playa. This does not include groundwater flow.
No Modifications No modifications are present. Use when no other options with the modification domain have been cited.
Overflow Channel or Flume An artificial channel built to control excess high flow from a natural channel; alters the natural flow out of the hydrologic unit.
Overbank Flow A natural condition in which a stream surpasses bankfull stage and the excess flows into a nearby channel draining to a different hydrologic unit (special condition; see example in fig. 18). Both the losing and the receiving hydrologic unit should carry this designation.
Pipe Diversion A redirection of surface water by a pipeline from one hydrologic unit to another; alters the natural flow out of the hydrologic unit.
Receiving A hydrologic unit that receives diverted water.
Reservoir A constructed basin formed to contain and store water for future use in an artificial lake; alters the natural flow out of the hydrologic unit.
Urban Area Heavy modification of hydrologic unit topography by development beyond that described in section 6.4.2.3, Transportation Feature, that alters natural flow out of the hydrologic unit.
Withdrawal A hydrologic unit from which water is diverted.
The 12-digit hydrologic unit ToHUC code attribute is the code for the 12-digit hydrologic unit that is downstream from and naturally receives the majority of the flow from another 12-digit hydrologic unit. For special cases when a downstream code cannot be assigned, identify which of these exceptions applies: If a hydrologic unit flows into an ocean or the Gulf of Mexico, then populate this field with the value OCEAN. If a hydrologic unit drains into either Canada or Mexico, then use the appropriate value CANADA or MEXICO. If a hydrologic unit is a closed basin, then populate this field with the value CLOSED BASIN.
U.S. Geological Survey, Earth Science Information Center
The noncontributing area attribute represents the area, in acres, of hydrologic units that do not contribute to downstream accumulation of streamflow under normal flow conditions (section 3.5.3). If a noncontributing area is on the boundary between two or more hydrologic units, then determine the low point along the noncontributing area boundary, and associate the noncontributing area with the hydrologic unit adjacent to the low point on the boundary. The value is the total acreage of the noncontributing areas within a hydrologic unit. North American Albers Equal Area Conic, North American Datum 1983 is the required projection to use for calculation. If the units of the area field are stored in square meters, then use the conversion factor 0.0002471.
U.S. Geological Survey, Earth Science Information Center
The noncontributing area attribute represents the area, in square kilometers, of hydrologic units that do not contribute to downstream accumulation of streamflow under normal flow conditions (section 3.5.3). If a noncontributing area is on the boundary between two or more hydrologic units, then determine the low point along the noncontributing area boundary, and associate the noncontributing area with the hydrologic unit adjacent to the low point on the boundary. The value is the total square kilometers of the noncontributing areas within a hydrologic unit. North American Albers Equal Area Conic, North American Datum 1983 is the required projection to use for calculation. If the units of the area field are stored in square meters, then use the conversion factor 0.0002471
U.S. Geological Survey, Earth Science Information Center
Description based on HUTYPE field. See HUTYPE for more information.
GeoPlan
GeoPlan added field based on NAME
GeoPlan
Date GeoPlan acquired from source.
GeoPlan
Unique ID added by GeoPlan
GeoPlan
Area in meters
GeoPlan
Perimeter in meters
GeoPlan
431 Architecture PO Box 115706
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