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National Hydrography Dataset (NHD) Data Dictionary Feature Domains

The data dictionary for feature domains (FCodes) in the National Hydrography Dataset.

FEATURE DOMAINS (FCODE DOMAIN)

Area of Complex Channels FCode

Feature Code Feature Description Feature Definition
53700 Area of Complex Channels (no attributes) An area where a stream or river flows in an intricate network of sediment-driven interlacing channels. Not named features.

Area to be Submerged FCode

Feature Code Feature Description Feature Definition
30700 Area to be Submerged (no attributes) The known extent of the intended lake that will be created behind a dam under construction. May be named feature.

ArtificialPath FCode

Feature Code Feature Description Feature Definition
55800 Artificial Path (no attributes) A surrogate for general flow direction in NHDWaterbodies and NHDAreas. Artificial Paths carry the name of the flowline feature. NHDArea StreamRivers will have an Artificial Path that will carry the name of the river.

BayInlet FCode

Feature Code Feature Description Feature Definition
31200 BayInlet (no attributes) A water area that is an opening of the sea/ocean into the land, or of an estuary, lake, or river into its shore. BayInlets are used in the NHD to provide named areas for other hydrographic features, and must overlap Estuary, LakePond, SeaOcean, or StreamRiver. May be named feature.

Bridge FCode

Feature Code Feature Description Feature Definition
31800 Bridge (no attributes) A structure spanning and providing passage of a waterway over another waterway, railroad, or other obstacle. Bridge also exists as an NHDLine. May be a named feature.

CanalDitch FCode

Feature Code Feature Description Feature Definition
33600 CanalDitch (CanalDitch Type = null) An artificial open waterway constructed to transport water, to irrigate or drain land, to connect two or more bodies of water, or to serve as a waterway for watercraft. May be a named feature.
33601 CanalDitch (CanalDitch Type = Aqueduct) An artificial, open waterway designed to transport domestic or industrial water from a supply source to a distribution point, often by gravity.
33603 CanalDitch (CanalDitch Type = Stormwater) An artificial, open waterway designed to convey stormwater through and from a drainage area.

Coastline FCode

Feature Code Feature Description Feature Definition
56600 Coastline (no attributes) A line of contact between the open sea and the land, including imaginary lines separating inland water bodies from the open sea. The NHD acquires coastline data from the National Ocean and Atmospheric Agency (NOAA) and it is not a product of the USGS. Coastline in the NHD is a representation of the Mean High Water (MHW) as calculated by NOAA and may not match orthoimagery. Coastline in the NHD could be altered but must have an accompanying metadata record that identifies the scientific method used to calibrate the coastline to a known vertical datum. Coastline may be a named feature.

Connector FCode

Feature Code Feature Description Feature Definition
33400 Connector (no attributes) A known, but nonspecific, invisible connection between two nonadjacent network segments.

DamWeir FCode

Feature Code Feature Description Feature Definition
34300 DamWeir (Construction Material = null) A barrier constructed to control the flow or raise the level of water. No information on the predominant construction material.
34305 DamWeir (Construction Material = Earthen) A barrier constructed to control the flow or raise the level of water where the predominant material used in construction is earth, or a combination of earth and rock.
34306 DamWeir (Construction Material = Nonearthen) A barrier constructed to control the flow or raise the level of water where the predominant material used in construction is concrete, brick, or stone. Coincident with a Nonearthen Shore Feature.

Drainageway FCode

Feature Code Feature Description Feature Definition
46800 Drainageway A drainageway is a watercourse that conveys, or is likely to convey water but lacks a clearly defined channel or banks differentiating it from an ephemeral stream/river. Drainageways typically convey water for limited periods of time and do not carry perennial flow. Drainageways may follow natural topographic flow paths or constructed or human-made flow paths.

Estuary FCode

Feature Code Feature Description Feature Definition
49300 Estuary (no attributes) An estuary is a semi-enclosed coastal body of water which has a free connection with the open sea and within which sea water is measurably diluted with fresh water derived from land drainage" (Cameron and Pritchard, 1963). An Estuary is defined by the NOAA's Coastal Aquatic Framework (CAF) or local information concerning the extent of the mixed zone of fresh and salt water.

Flume FCode

Feature Code Feature Description Feature Definition
36200 Flume (no attributes) An open, inclined, artificial channel constructed of wood, metal, or concrete; generally elevated. Flume also exists as an NHDLine. May be a named feature.

Foreshore FCode

Feature Code Feature Description Feature Definition
36400 Foreshore (no attributes) The area of shore that lies between the limits of the mean high water (MHW) and mean low low water (MLLW) tidal marks and is exposed during low tides. The NHD acquires Foreshore data from the National Ocean and Atmospheric Agency (NOAA) and it is not a product of the USGS. May be a named feature.

Gaging Station FCode

Feature Code Feature Description Feature Definition
36700 Gaging Station (no attributes) A structure used to measure the characteristics of a hydrographic feature. Stream Gages are usually captured on the flowline and not necessarily on the physical location of the monitoring station. Stream Gages are also available as a Point Event. Not a named feature.
36701 Gaging Station (Gaging Station Status=Active; Record=Continuous) A structure used to measure the characteristics of a hydrographic feature. Stream Gages are usually captured on the flowline and not necessarily on the physical location of the monitoring station. A site is considered active if: (1) it has collected time-series (automated) data within the last 183 days (6 months), or (2) it has collected discrete (manually collected) data within 397 days (13 months). Where data collection is continuous, data may be available in real-time, as individual observations, or as daily summaries.

Gaging Station: Gaging Station Status = Active; Record = Partial

Feature Code Feature Description Feature Definition
36702 Gaging Station (Gaging Station Status = Active; Record = Partial)  

Gaging Station: Gaging Station Status = Inactive

Feature Code Feature Description Feature Definition
36703 Gaging Station (Gaging Station Status = Inactive)  

Gate FCode

Feature Code Feature Description Feature Definition
36900 Gate (no attributes) A structure that may be swung, drawn, or lowered to block an entrance or passageway. Gate may also be found as a line feature. Gate also exists as an NHDLine. Not a named feature.

Ice Mass FCode

Feature Code Feature Description Feature Definition
37800 Ice Mass (no attributes) A field of ice usually formed in regions of perennial frost. Ice Mass primarily consists of glaciers. May be a named feature.

Inundation Area FCode

Feature Code Feature Description Feature Definition
40300 Inundation Area (Innundation Control Status = null, Stage = null) An area of land subject to flooding. No information on the existence of functional structures controlling the flow of water into the area. No information on the height of the water surface.
40307 Inundation Area (Innundation Control Status = Not Controlled, Stage = null) An area of land subject to flooding. No controlling structures exist; flooding is natural and periodic. No information on the height of the water surface.
40308 Inundation Area (Innundation Control Status = Controlled, Stage = null) An area of land subject to flooding. Functional structures such as a levee or DamWeir, exist to control the water and inundate specific areas. No information on the height of the water surface.
40309 Inundation Area (Innundation Control Status = Controlled, Stage = Flood Elevation) An area of land subject to flooding. Functional structures, such as a levees or DamWeirs, exist to control the water and inundate specific areas. Height of the surface water is flood elevation (the stage that prevails when a natural water body is at or near capacity).

LakePond FCode

Feature Code Feature Description Feature Definition
39000 LakePond (Hydrographic Category = null, Stage = null) A standing body of water with a predominantly natural shoreline surrounded by land or a flooded river system where a dam has been built to withhold water. Portion of the year the LakePond contains water is unknown. Height of the water surface is unknown.
39001 LakePond (Hydrographic Category = Intermittent, Stage = null) A standing body of water with a predominantly natural shoreline surrounded by land or a flooded river system where a dam has been built to withhold water. Contains water for only part of the year, but more than just after rainstorms and at snowmelt. Height of the water surface is unknown.
39004 LakePond (Hydrographic Category = Perennial, Stage = null) A standing body of water with a predominantly natural shoreline surrounded by land or a flooded river system where a dam has been built to withhold water. Contains water throughout the year, except for infrequent periods of severe drought. Height of the water surface is unknown.
39005 LakePond (Hydrographic Category = Intermittent, Stage = High Water Elevation) A standing body of water with a predominantly natural shoreline surrounded by land or a flooded river system where a dam has been built to withhold water. Contains water for only part of the year, but more than just after rainstorms and at snowmelt. Height of the water surface is the stage that prevails when a natural water body is at or near capacity.
39006 LakePond (Hydrographic Category = Intermittent, Stage = Date of Photography) A standing body of water with a predominantly natural shoreline surrounded by land or a flooded river system where a dam has been built to withhold water. Contains water for only part of the year, but more than just after rainstorms and at snowmelt. Height of the water surface is the stage that exists at the date of the photography.
39009 LakePond (Hydrographic Category = Perennial, Stage = Average Water Elevation) A standing body of water with a predominantly natural shoreline surrounded by land or a flooded river system where a dam has been built to withhold water. Contains water throughout the year, except for infrequent periods of severe drought. Height of the water surface is the the stage of a natural water body that prevails for the greater part of the year.
39010 LakePond (Hydrographic Category = Perennial, Stage = Normal Pool) A standing body of water with a predominantly natural shoreline surrounded by land or a flooded river system where a dam has been built to withhold water. Contains water throughout the year, except for infrequent periods of severe drought. Height of the water surface is the stage of an artificially impounded water body that prevails for the greater part of the year.
39011 LakePond (Hydrographic Category = Perennial, Stage = Date of Photography) A standing body of water with a predominantly natural shoreline surrounded by land or a flooded river system where a dam has been built to withhold water. Contains water throughout the year, except for infrequent periods of severe drought. Height of the water surface is the stage that exists at the date of the photography.
39012 LakePond (Hydrographic Category = Perennial, Stage = Spillway Elevation) A standing body of water with a predominantly natural shoreline surrounded by land or a flooded river system where a dam has been built to withhold water. Contains water throughout the year, except for infrequent periods of severe drought. Height of the water surface is the stage of an artificially impounded water body as determined by the spillway.

Levee FCode

Feature Code Feature Description Feature Definition
56800 Levee (no attributes) An embankment built to prevent flooding or to control or confine the flow of liquids. Levee also exists as an NHDLine. Not a named feature.

Lock Chamber FCode

Feature Code Feature Description Feature Definition
39800 Lock Chamber (no attributes) An enclosure on a waterway used to raise and lower vessels as they pass from one level to another. Lock Chamber also exists as an NHDPoint or as an NHDLine. May be a named feature.

Nonearthen Shore FCode

Feature Code Feature Description Feature Definition
41100 Nonearthen Shore (no attributes) A structure built of stone, brick, concrete, or other building materials that borders a body of water. Not a named feature.

Pipeline FCode

Feature Code Feature Description Feature Definition
42800 Pipeline (Product = null, Pipeline Type = null, Relationship to Surface = null) A closed conduit, with pumps, valves and control devices, for conveying fluids, gases, or finely divided solids. Type of product conveyed by pipeline unknown. Type of function or purpose of pipeline unknown. Vertical location of pipeline relative to the surface unknown.
42801 Pipeline (Product = water, Pipeline Type = Aqueduct, Relationship to Surface = At or near) A closed conduit, with pumps, valves and control devices, for conveying fluids, gases, or finely divided solids. Aqueduct pipeline, designed to transport domestic or industrial water from a supply source to a distribution point, often by gravity. Vertical location of pipeline is at or near the surface.
42802 Pipeline (Product = water, Pipeline Type = Aqueduct, Relationship to Surface = Elevated) A closed conduit, with pumps, valves and control devices, for conveying fluids, gases, or finely divided solids. Aqueduct pipeline, designed to transport domestic or industrial water from a supply source to a distribution point, often by gravity. Vertical location of pipeline is elevated (supported above the earth).
42803 Pipeline (Product = water, Pipeline Type = Aqueduct, Relationship to Surface = Underground) A closed conduit, with pumps, valves and control devices, for conveying fluids, gases, or finely divided solids. Aqueduct pipeline, designed to transport domestic or industrial water from a supply source to a distribution point, often by gravity. Vertical location of pipeline is underground (buried below the surface).
42804 Pipeline (Product = water, Pipeline Type = Aqueduct, Relationship to Surface = Underwater) A closed conduit, with pumps, valves and control devices, for conveying fluids, gases, or finely divided solids. Aqueduct pipeline, designed to transport domestic or industrial water from a supply source to a distribution point, often by gravity. Vertical location of pipeline is underwater (always submerged).
42805 Pipeline (Product = water, Pipeline Type = General Case, Relationship to Surface = At or near) A closed conduit, with pumps, valves and control devices, for conveying fluids, gases, or finely divided solids. General case (common use) pipeline, used to channel flowing water to another site. Vertical location of pipeline is at or near the surface.
42806 Pipeline (Product = water, Pipeline Type = General Case, Relationship to Surface = Elevated) A closed conduit, with pumps, valves and control devices, for conveying fluids, gases, or finely divided solids. General case (common use) pipeline, used to channel flowing water to another site. Vertical location of pipeline is elevated (supported above the earth).
42807 Pipeline (Product = water, Pipeline Type = General Case, Relationship to Surface = Underground) A closed conduit, with pumps, valves and control devices, for conveying fluids, gases, or finely divided solids. General case (common use) pipeline, used to channel flowing water to another site. Vertical location of pipeline is underground (buried below the surface).
42808 Pipeline (Product = water, Pipeline Type = General Case, Relationship to Surface = Underwater) A closed conduit, with pumps, valves and control devices, for conveying fluids, gases, or finely divided solids. General case (common use) pipeline, used to channel flowing water to another site. Vertical location of pipeline is underwater (always submerged).
42809 Pipeline (Product = water, Pipeline Type = Penstock, Relationship to Surface = At or near) A closed conduit, with pumps, valves and control devices, for conveying fluids, gases, or finely divided solids. Penstock pipeline, designed to convey water into the turbine of a hydroelectric generating plant. Vertical location of pipeline is at or near the surface.
42810 Pipeline (Product = water, Pipeline Type = Penstock, Relationship to Surface = Elevated) A closed conduit, with pumps, valves and control devices, for conveying fluids, gases, or finely divided solids. Penstock pipeline, designed to convey water into the turbine of a hydroelectric generating plant. Vertical location of pipeline is elevated (supported above the earth).
42811 Pipeline (Product = water, Pipeline Type = Penstock, Relationship to Surface = Underground) A closed conduit, with pumps, valves and control devices, for conveying fluids, gases, or finely divided solids. Penstock pipeline, designed to convey water into the turbine of a hydroelectric generating plant. Vertical location of pipeline is underground (buried below the surface).
42812 Pipeline (Product = water, Pipeline Type = Penstock, Relationship to Surface = Underwater) A closed conduit, with pumps, valves and control devices, for conveying fluids, gases, or finely divided solids. Penstock pipeline, designed to convey water into the turbine of a hydroelectric generating plant. Vertical location of pipeline is underwater (always submerged).
42813 Pipeline (Product = water, Pipeline Type = Siphon, Relationship to Surface = Unspecified) A closed conduit, with pumps, valves and control devices, for conveying fluids, gases, or finely divided solids. Siphon pipeline, designed to convey water by gravitational force over, or under, an obstruction. Vertical location of pipeline is The value is not known and is not required.
42814 Pipeline (Product = water, Pipeline Type = General Case, Relationship to Surface = null) A closed conduit, with pumps, valves and control devices, for conveying fluids, gases, or finely divided solids. General case (common use) pipeline, used to channel flowing water to another site. Vertical location of pipeline is unknown.
42815 Pipeline (Product = water, Pipeline Type = Penstock, Relationship to Surface = null) A closed conduit, with pumps, valves and control devices, for conveying fluids, gases, or finely divided solids. Penstock pipeline, designed to convey water into the turbine of a hydroelectric generating plant. Vertical location of pipeline is unknown.
42816 Pipeline (Product = water, Pipeline Type = Aqueduct, Relationship to Surface = null) A closed conduit, with pumps, valves and control devices, for conveying fluids, gases, or finely divided solids. Aqueduct pipeline, designed to transport domestic or industrial water from a supply source to a distribution point, often by gravity. Vertical location of pipeline is unknown.
42820 Pipeline (Product = water, Pipeline Type = Stormwater, Relationship to Surface = null) A closed conduit, with pumps, valves and control devices, for conveying fluids, gases, or finely divided solids. Stormwater pipeline, designed to convey stormwater through and from a drainage area. Vertical location of pipeline is unknown.
42821 Pipeline (Product = water, Pipeline Type = Stormwater, Relationship to Surface = At or near) A closed conduit, with pumps, valves and control devices, for conveying fluids, gases, or finely divided solids. Stormwater pipeline, designed to convey stormwater through and from a drainage area. Vertical location of pipeline is at or near the surface.
42822 Pipeline (Product = water, Pipeline Type = Stormwater, Relationship to Surface = Elevated) A closed conduit, with pumps, valves and control devices, for conveying fluids, gases, or finely divided solids. Stormwater pipeline, designed to convey stormwater through and from a drainage area. Vertical location of pipeline is elevated (supported above the earth).
42823 Pipeline (Product = water, Pipeline Type = Stormwater, Relationship to Surface = Underground) A closed conduit, with pumps, valves and control devices, for conveying fluids, gases, or finely divided solids. Stormwater pipeline, designed to convey stormwater through and from a drainage area. Vertical location of pipeline is underground (buried below the surface).
42824 Pipeline (Product = water, Pipeline Type = Stormwater, Relationship to Surface = Underwater) A closed conduit, with pumps, valves and control devices, for conveying fluids, gases, or finely divided solids. Stormwater pipeline, designed to convey stormwater through and from a drainage area. Vertical location of pipeline is underwater (always submerged).

Playa FCode

Feature Code Feature Description Feature Definition
36100 Playa (no attributes) The flat area at the lowest part of an undrained desert basin, generally devoid of vegetation. May be a named feature.

Rapids FCode

Feature Code Feature Description Feature Definition
43100 Rapids (no attributes) An area of swift current in a stream or river, characterized by standing waves or by boulders and rocks. Rapids also exist as NHDPoint or as NHDLine. May be a named feature.

Reef FCode

Feature Code Feature Description Feature Definition
43400 Reef (no attributes) A Chain of rocks or coral at or near the surface of the water. May be a named feature.

Reservoir FCode

Feature Code Feature Description Feature Definition
43600 Reservoir (Reservoir Type = null, Construction Material = null, Hydrographic Category = null) A constructed basin formed to contain water or other liquids. Function or purpose of resevoir is unknown. Predominant construction material used to construct the reservoir is unknown. The portion of the year the feature contains water is unknown.
43601 Reservoir (Reservoir Type = Aquaculture, Construction Material = null, Hydrographic Category = null) A constructed basin formed to contain water or other liquids. Aquaculture reservoir used for rearing finfish, shell fish, or aquatic plants. Predominant construction material used to construct the reservoir is unknown. The portion of the year the feature contains water is unknown.
43603 Reservoir (Reservoir Type = Decorative Pool, Construction Material = null, Hydrographic Category = null) A constructed basin formed to contain water or other liquids. Decorative pool reservoir used for improving the aesthetic appearance of the landscape. Predominant construction material used to construct the reservoir is unknown. The portion of the year the feature contains water is unknown.
43604 Reservoir (Reservoir Type = Disposal - Tailing Pond, Construction Material = Earthen, Hydrographic Category = null) A constructed basin formed to contain water or other liquids. Tailing pond reservoir used for the disposal of tailing. Predominant construction material used to construct the reservoir is earthen, or a combination of earth and rock. The portion of the year the feature contains water is unknown.
43605 Reservoir (Reservoir Type = Disposal - Tailings Pond, Construction Material = null, Hydrographic Category = null) A constructed basin formed to contain water or other liquids. Tailing pond reservoir used for the disposal of tailing. Predominant construction material used to construct the reservoir is unknown. The portion of the year the feature contains water is unknown.
43606 Reservoir (Reservoir Type = Disposal - unspecified, Construction Material = null, Hydrographic Category = null) A constructed basin formed to contain water or other liquids. Disposal reservoir (function/purpose is not known and is not required). Predominant construction material used to construct the reservoir is unknown. The portion of the year the feature contains water is unknown.
43607 Reservoir (Reservoir Type = Evaporator, Construction Material = null, Hydrographic Category = null) A constructed basin formed to contain water or other liquids. Evaporator reservoir for natural evaporation of water to allow harvesting of mineral concentrates. Predominant construction material used to construct the reservoir is unknown. The portion of the year the feature contains water is unknown.
43608 Reservoir (Reservoir Type = Swimming Pool, Construction Material = null, Hydrographic Category = null) A constructed basin formed to contain water or other liquids. Swimming pool reservoir, used for recreation. Predominant construction material used to construct the reservoir is unknown. The portion of the year the feature contains water is unknown.
43609 Reservoir (Reservoir Type = Treatment - Cooling Pond, Construction Material = null, Hydrographic Category = null) A constructed basin formed to contain water or other liquids. Treatment reservoir, used as a cooling pond. Predominant construction material used to construct the reservoir is unknown. The portion of the year the feature contains water is unknown.
43610 Reservoir (Reservoir Type = Treatment - Filtration Pond, Construction Material = null, Hydrographic Category = null) A constructed basin formed to contain water or other liquids. Treatment reservoir, used as a filtration pond. Predominant construction material used to construct the reservoir is unknown. The portion of the year the feature contains water is unknown.
43611 Reservoir (Reservoir Type = Treatment - Settling Pond, Construction Material = Unspecified, Hydrographic Category = null) A constructed basin formed to contain water or other liquids. Treatment reservoir, used as a settling pond. Predominant construction material used to construct the reservoir is not known and is not required. The portion of the year the feature contains water is unknown.
43612 Reservoir (Reservoir Type = Treatment - Sewage Treatment Pond, Construction Material = null, Hydrographic Category = null) A constructed basin formed to contain water or other liquids. Treatment reservoir, used as a sewage treatment pond. Predominant construction material used to construct the reservoir is unknown. The portion of the year the feature contains water is unknown.
43613 Reservoir (Reservoir Type = Water Storage, Construction Material = Nonearthen, Hydrographic Category = null) A constructed basin formed to contain water or other liquids. Water Storage reservoir, used or long or short-term storage of water. Predominant construction material used to construct the reservoir is concrete, brick, or stone. The portion of the year the feature contains water is unknown.
43614 Reservoir (Reservoir Type = Water Storage, Construction Material = Earthen, Hydrographic Category = Intermittent) A constructed basin formed to contain water or other liquids. Water Storage reservoir, used or long or short-term storage of water. Predominant construction material used to construct the reservoir is earth, or a combination of earth and rock. The reservoir contains water for only part of the year, but more than just after rainstorms and at snowmelt.
43615 Reservoir (Reservoir Type = Water Storage, Construction Material = Earthen, Hydrographic Category = Perennial) A constructed basin formed to contain water or other liquids. Water Storage reservoir, used or long or short-term storage of water. Predominant construction material used to construct the reservoir is earth, or a combination of earth and rock. The reservoir contains water throughout the year, except for infrequent periods of severe drought.
43617 Reservoir (Reservoir Type = Water Storage, Construction Material = null, Hydrographic Category = null) A constructed basin formed to contain water or other liquids. Water Storage reservoir, used or long or short-term storage of water. Predominant construction material used to construct the reservoir is unknown. The portion of the year the feature contains water is unknown.
43618 Reservoir (Reservoir Type = Unspecified, Construction Material = Earthen, Hydrographic Category = null) A constructed basin formed to contain water or other liquids. Type of reservoir is not known and is not required. Predominant construction material used to construct the reservoir is earth, or a combination of earth and rock. The portion of the year the feature contains water is unknown.
43619 Reservoir (Reservoir Type = Unspecified, Construction Material = Nonearthen, Hydrographic Category = null) A constructed basin formed to contain water or other liquids. Type of reservoir is not known and is not required. Predominant construction material used to construct the reservoir is concrete, brick, or stone. The portion of the year the feature contains water is unknown.
43621 Reservoir (Reservoir Type = Water Storage, Construction Material = null, Hydrographic Category = Perennial) A constructed basin formed to contain water or other liquids. Water Storage reservoir, used or long or short-term storage of water. Predominant construction material is unknown. The reservoir contains water throughout the year, except for infrequent periods of severe drought.
43623 Reservoir (Reservoir Type = Evaporator, Construction Material = Earthen, Hydrographic Category = null) A constructed basin formed to contain water or other liquids. Evaporator reservoir for natural evaporation of water to allow harvesting of mineral concentrates. Predominant construction material used to construct the reservoir is earth, or a combination of earth and rock. The portion of the year the feature contains water is unknown.
43624 Reservoir (Reservoir Type = Treatment, Construction Material = null, Hydrographic Category = null) A constructed basin formed to contain water or other liquids. Treatment reservoir. Predominant construction material used is unknown. The portion of the year the feature contains water is unknown.
43625 Reservoir (Reservoir Type = Disposal, Construction Material = earthen, Hydrographic Category = null) A constructed basin formed to contain water or other liquids. Disposal Reservoir. Predominant construction material used to construct the reservoir is unknown. The portion of the year the feature contains water is unknown.
43626 Reservoir (Reservoir Type = Disposal, Construction Material = Nonearthen, Hydrographic Category = null) A constructed basin formed to contain water or other liquids. Disposal Reservoir. Predominant construction material used to construct the reservoir is concrete, brick, or stone. The portion of the year the feature contains water is unknown.

Rock FCode

Feature Code Feature Description Feature Definition
44100 Rock (Relationship to Surface = null) A concreted mass of stony material.
44101 Rock (Relationship to Surface = Abovewater) A concreted mass of stony material. The vertical location of the rock relative to the surface is above water (exposed at mean lower low water).
44102 Rock (Relationship to Surface = Underwater) A concreted mass of stony material. The vertical location of the rock relative to the surface is underwater (always submerged).

SeaOcean FCode

Feature Code Feature Description Feature Definition
44500 SeaOcean (no attributes) The great body of salt water that covers much of the earth. May be a named feature.

SinkRise FCode

Feature Code Feature Description Feature Definition
45000 SinkRise (Flow = Unknown) The place at which a stream disappears underground or reappears at the surface, such as in a karst area. The flow direction is unknown.
45001 SinkRise (Type = Sink, Flow = Into Ground) The place at which a stream disappears underground, such as in a karst area.
45002 SinkRise (Type = Rise, Flow = Out of Ground) The place at which a stream reappears at the surface, such as in a karst area.
45003 SinkRise (Type = Estevelle, Flow = Bidirectional) The place at which, depending on weather conditions and season, a stream disappears underground or reappears at the surface, such as in a karst area.

Sounding Datum Line FCode

Feature Code Feature Description Feature Definition
50300 Sounding Datum Line (Positional Accuracy = null) A line representing the bathymetric contour of mean low low water (MLLW) for which a foreshore feature is present or visible. The NHD acquires Sounding Datum Line data from the National Ocean and Atmospheric Agency (NOAA) and it is not a product of the USGS. The accuracy within which the feature may be confidently positioned is unknown.
50301 Sounding Datum Line (Positional Accuracy = Approximate) A line representing the bathymetric contour of mean low low water (MLLW) for which a foreshore feature is present or visible. The NHD acquires Sounding Datum Line data from the National Ocean and Atmospheric Agency (NOAA) and it is not a product of the USGS. The accuracy within which the feature may be confidently positioned is approximate (conditions permit the feature to be confidently positioned between 0.02" and 0.1", at map scale, of its true ground position).
50302 Sounding Datum Line (Positional Accuracy = Definite) A line representing the bathymetric contour of mean low low water (MLLW) for which a foreshore feature is present or visible. The NHD acquires Sounding Datum Line data from the National Ocean and Atmospheric Agency (NOAA) and it is not a product of the USGS. The accuracy within which the feature may be confidently positioned is definite (conditions permit the feature to be confidently positioned. Horizontal data are confidently positioned within 0.02", at map scale, of the true ground position. Vertical data are confidently positioned within one-half contour interval of the true ground position).

Spillway FCode

Feature Code Feature Description Feature Definition
45500 Spillway (no attributes) A constructed passage for surplus water to run over or around a dam.

SpringSeep FCode

Feature Code Feature Description Feature Definition
45800 SpringSeep (no attributes) A place where water issues from the ground naturally. May be a named feature.

StreamRiver FCode

Feature Code Feature Description Feature Definition
46000 StreamRiver (no attributes) A body of flowing water. Portion of the year the feature contains water unknown.
46003 StreamRiver (Hydrographic Category = Intermittent) A body of flowing water that contains water for only part of the year, but more than just after rainstorms and at snowmelt.
46006 StreamRiver (Hydrographic Category = Perennial) A body of flowing water that contains water throughout the year, except for infrequent periods of severe drought.
46007 StreamRiver (Hydrographic Category = Ephemeral) A body of flowing water that contains water only during or after a local rainstorm or heavy snowmelt.

Submerged Stream FCode

Feature Code Feature Description Feature Definition
46100 Submerged Stream (no attributes) The original river course inundated by an impounded water body. These are mostly used in drowned river systems like the Tennessee Valley Authority (TVA) lakes. May be a named feature.

SwampMarsh FCode

Feature Code Feature Description Feature Definition
46600 SwampMarsh (Hydrographic Category = null) A noncultivated, vegetated area that is inundated or saturated for a significant part of the year. The vegetation is adapted for life in saturated soil conditions.
46601 SwampMarsh (Hydrographic Category = Intermittent) A noncultivated, vegetated area that is inundated or saturated for a significant part of the year. The vegetation is adapted for life in saturated soil conditions. Contains water for only part of the year, but more than just after rainstorms and at snowmelt.
46602 SwampMarsh (Hydrographic Category = Perennial) A noncultivated, vegetated area that is inundated or saturated for a significant part of the year. The vegetation is adapted for life in saturated soil conditions. Contains water throughout the year, except for infrequent periods of severe drought.

Tunnel FCode

Feature Code Feature Description Feature Definition
47800 Tunnel (no attributes) An underground or underwater passage that carries water bearing features such as CanalDitch or Pipeline. May be a named feature.

Underground Conduit FCode

Feature Code Feature Description Feature Definition
42000 Underground Conduit (Positional Accuracy = null) A set of naturally occurring subsurface drainage channels formed from the dissolution of soluble rocks in Karst terrain or in terrain similar to karst but formed in nonsoluble rocks, as by melting of permafrost or ground ice, collapse after mining, and by outflow of liquid lava from beneath its solidified crust. The accuracy within which the feature may be confidently positioned is unknown.
42001 Underground Conduit (Positional Accuracy = Definite) A set of naturally occurring subsurface drainage channels formed from the dissolution of soluble rocks in Karst terrain or in terrain similar to karst but formed in nonsoluble rocks, as by melting of permafrost or ground ice, collapse after mining, and by outflow of liquid lava from beneath its solidified crust. The accuracy within which the feature may be confidently positioned is definite (conditions permit the feature to be confidently positioned. Horizontal data are confidently positioned within 0.02" (40 feet at 1:24,000 scale), at map scale, of true ground position).
42002 Underground Conduit (Positional Accuracy = Indefinite) A set of naturally occurring subsurface drainage channels formed from the dissolution of soluble rocks in Karst terrain or in terrain similar to karst but formed in nonsoluble rocks, as by melting of permafrost or ground ice, collapse after mining, and by outflow of liquid lava from beneath its solidified crust. The accuracy within which the feature may be confidently positioned is indefinite (conditions prevent the feature from being confidently positioned. Horizontal data cannot be confidently positioned within 0.02", at map scale, of the true ground position).
42003 Underground Conduit (Positional Accuracy = Approximate) A set of naturally occurring subsurface drainage channels formed from the dissolution of soluble rocks in Karst terrain or in terrain similar to karst but formed in nonsoluble rocks, as by melting of permafrost or ground ice, collapse after mining, and by outflow of liquid lava from beneath its solidified crust. The accuracy within which the feature may be confidently positioned is approximate (conditions permit the feature to be confidently positioned between 0.02" and 0.1", at map scale, of its true ground position.).

Wall FCode

Feature Code Feature Description Feature Definition
48300 Wall (no attributes) An upright structure of masonry, wood, plaster, or other building material serving to separate land from water with no additional structures present. If other associated structures, such as DamWeir, are present use Nonearthen Shore. Not a named feature.

Wash FCode

Feature Code Feature Description Feature Definition
48400 Wash (no attributes) The usually dry portion of a stream bed that contains water only during or after a local rainstorm or heavy snowmelt. May be a named feature.

Waterfall FCode

Feature Code Feature Description Feature Definition
48700 Waterfall (no attributes) A vertical or near vertical descent of water over a step or ledge in the bed of a river. Waterfall also exists as an NHDPoint. May be a named feature.

Water IntakeOutflow FCode

Feature Code Feature Description Feature Definition
48500 Water Intake/Outflow (no attributes) A structure through which water enters or exits through a divergence structure. Water Intake/Outflow also exists as an NHDPoint. Not a named feature.

Well FCode

Feature Code Feature Description Feature Definition
48800 Well (no attributes) A pit or hole dug or bored into the earth for the extraction of oil, water, other fluids, or gases. May be a named feature.

NONFCODE DOMAINS

Area Event Type Domain

Code Description Definition

ElevationRange

Code Description Definition
MaxValue 9000  
MinValue -400  

"Enabled" attribute values

Code Description Definition
0 Not enabled Not enabled, shown as False in the geodatabase.
1 Enabled Enabled, shown as True in the geodatabase.

HydroFlowDirections

Code Description Definition
0 Uninitialized Direction of flow relative to coordinate order is uninitialized.
1 WithDigitized Direction of flow relative to coordinate order is witih digitized.

Line Event Type

Code Description Definition

MainPath

Code Description Definition
0 Unspecified Unspecified
1 Confluence Main Location where separate streams join the main path.
2 Divergence Main Location where the main path diverges into separate streams.
3 Both Confluence Main and Divergence Main Location where streams both converge and diverge from main path.

NoYesDomain

Code Description Definition
0 No No
1 Yes Yes

Point Event Type

Code Description Definition
1 Gaging Station The entity in the event is a gaging station.
2 Dam The entity in the event is a dam.
3 Divergence Structure = General The entity in the event is a general divergence structure.
4 Divergence Structure = Withdrawing The entity in the event is a withdrawing divergence structure.
5 Divergence Structure = Contributing The entity in the event is a contributing divergence structure.
57001 Streamgage; Status=Active; Record=Continuous A structure used to measure the characteristics of a hydrographic feature. Gages are usually captured on the flowline, not necessarily on the physical location of the monitoring station. Site is active if: has collected time-series data within the last 183 days, or has collected discrete data within 397 days. Where data collection is continuous, data may be available in real-time, as individual observations, or as daily summaries, and data are collected on a regularly scheduled basis.
57002 Streamgage Status=Active; Record=Partial Structure used to measure the characteristics of a hydrographic feature. Gages are usually captured on the flowline and not necessarily on the physical location of the monitoring station. Considered active if: has collected time-series data within the last 183 days, or has collected discrete data within 397 days. A partial-record station is a site where limited water-quality data are collected systematically over a period of years. Frequency of sampling is usually less than quarterly.
57003 Streamgage Status=Inactive A structure used to measure the characteristics of a hydrographic feature. Gages are usually captured on the flowline and not necessarily on the physical location of the monitoring station. Considered active if: has collected time-series data within the last 183 days, or has collected discrete data within 397 days. If it does not meet these criteria, it is considered inactive.
57004 Water Quality Station A point on the surface water network where a water sample is measured for water quality characteristics.
57100 Dam A barrier constructed to hold back water and raise its level, the resulting reservoir being used in the generation of electricity or as a water supply.
57201 Flow Alteration=Addition A point on the NHD surface water network where water is added to the network, typically through a conveyance such as a CanalDitch or pipeline.
57202 Flow Alteration=Removal A point on the NHD surface water network where water is removed from the network, typically through a conveyance such as a CanalDitch or pipeline. 
57203 Flow Alteration Unknown A point on the NHD surface water network where water is either removed or added to the network, typically through a conveyance such as a CanalDitch or pipeline.  
57300 Hydrologic Unit Outlet The pour point of a watershed boundary dataset hydrologic unit.
6 Water Quality Station The entity in the event is a water quality station.

Resolution

Code Description Definition
1 Local 1:12,000 source resolution.
2 High 1:24,000 - 12,000 source resolution.
3 Medium 1:100,000 source resolution.

StatusFlag Domain

Code Description Definition
A Add  
C Change  
D Delete  
N Not Set  

VisibilityFilter

Code Description Definition
0 Unspecified Objects with a Visibility Attribute = 0 have not been evaluated
100000 Approximately 1:100,000 or Larger Scale Objects with a Visibility Attribute = 100000 indicates that it is not appropriate to use the object at scales smaller than approximately 1:100,000 (i.e. object should be pruned at scales smaller than 1:100,000)
1000000 Approximately 1:1,000,000 or Larger Objects with a Visibility Attribute = 1000000 indicates that it is not appropriate to use the object at scales smaller than approximately 1:1,000,000 (i.e. object should be pruned at scales smaller than 1:1,000,000)
12500 Approximately 1:12,500 or Larger Scale Objects with a Visibility Attribute = 12500 indicates that it is not appropriate to use the object at scales smaller than approximately 1:12,500 (i.e. object should be pruned at scales smaller than 1:12,500)
150000 Approximately 1:150,000 or Larger Scale Objects with a Visibility Attribute = 150000 indicates that it is not appropriate to use the object at scales smaller than approximately 1:150,000 (i.e. object should be pruned at scales smaller than 1:150,000)
2000000 Approximately 1:2,000,000 or Larger Scale Objects with a Visibility Attribute = 2000000 indicates that it is not appropriate to use the object at scales smaller than approximately 1:2,000,000 (i.e. object should be pruned at scales smaller than 1:2,000,000)
24000 Approximately 1:24,000 or Larger Scale Objects with a Visibility Attribute = 24000 indicates that it is not appropriate to use the object at scales smaller than approximately 1:24,000 (i.e. object should be pruned at scales smaller than 1:24,000)
250000 Approximately 1:250,000 or Larger Scale Objects with a Visibility Attribute = 250000 indicates that it is not appropriate to use the object at scales smaller than approximately 1:250,000 (i.e. object should be pruned at scales smaller than 1:250,000)
4800 Approximately 1:4,800 or Larger Scale Objects with a Visibility Attribute = 4800 indicates that it is not appropriate to use the object at scales smaller than approximately 1:4,800 (i.e. object should be pruned at scales smaller than 1:4,800)
50000 Approximately 1:50,000 or Larger Scale Objects with a Visibility Attribute = 50000 indicates that it is not appropriate to use the object at scales smaller than approximately 50,000 (i.e. object should be pruned at scales smaller than 1:50,000)
500000 Approximately 1:500,000 or Larger Scale Objects with a Visibility Attribute = 500000 indicates that it is not appropriate to use the object at scales smaller than approximately 1:500,000 (i.e. object should be pruned at scales smaller than 1:500,000)
5000000 Approximately 1:5,000,000 or Larger Scale Objects with a Visibility Attribute = 5000000 indicates that it is not appropriate to use the object at scales smaller than approximately 1:5,000,000 (i.e. object should be pruned at scales smaller than 5,000,000)