Elevation-Derived Hydrography READ Rules: Pipeline
A Pipeline is A surface or subsurface, closed, constructed conduit for conveying water.
Attribute/Attribute Value
Each feature requires domain codes to be entered into the attribute table for the feature class (Elevation-Derived Hydrography Feature type description, associated geometry, and use classification table in the Elevation-Derived Hydrography Data Acquisition Specifications 2023 revision A2). See “Field Definitions and Domain Values for Attributes” section for more information on Elevation-Derived Hydrography code definitions.
Delineation
The limit of an underground pipeline is the edge of the ground scars or linear clearings, or other above ground artifacts that can be detected from ancillary data or other methods.
The limit of a near-ground or elevated pipeline is the extent of the structure.
Representation Rules
When delineating a feature, it must be created with the appropriate geometry, either point, line, or polygon, which is determined by the size of the feature or the length along different axes of the feature (table 11).
Special conditions: none.
Table 11. Pipeline Representation Rules.
| Kind of feature object | Area | Shortest Axis | Longest Axis |
| 0-dimensional (point) | -- | -- | -- |
| 1-dimensional (line) | -- | greater than 0 | greater than 5 feet (1.5 meters) above ground or 50 feet (~15 meters) underground |
| 2-dimensional (polygon) | -- | -- | -- |
Data Extraction
Capture Conditions
Above Ground
If pipeline conveys water between natural water features such as stream/river or lake/pond features, is above ground, is not underwater, and is greater than or equal to 5 feet (1.5 meters) along the longest axis,
then capture.
Note: the pipeline must connect to existing water features or water conveyance on both ends.
Underground
If pipeline conveys water underground, is in legacy NHD, or the pipeline is greater than 50 feet in length from other ancillary sources,
then capture.
Note: the only required pipelines to capture are those above ground, but if an ancillary source is used, an underground pipeline can be added to connect above ground features. Source of the ancillary data must be cited.
Through Transportation Feature
If pipeline conveys water under a road, and the road is less than 50 feet (approximately 15 meters) in width,
then capture as a culvert (add EClass of 3) see culvert description for FCode, and not as pipeline.
Attribute Information
FClass 2— Hydrography feature captured outside the collection criteria of the elevation-derived hydrography specifications.
FCode 42800—Pipeline (A surface or subsurface, closed, constructed conduit for conveying water).
EClass 0— Not used for elevation derivative.
OR
FClass 1—Hydrography feature defined within the collection criteria of the elevation-derived hydrography specifications.
FCode 42800—Pipeline (A surface or subsurface, closed, constructed conduit for conveying water).
EClass 2— Linear hydrographic features that follow the elevation surface.
OR
FClass 1—Hydrography feature defined within the collection criteria of the elevation-derived hydrography specifications.
FCode 42800—Pipeline (A surface or subsurface, closed, constructed conduit for conveying water).
EClass 3— Linear features below ground level—Examples include connectors through dams, culvert connectors, and terrain breach connectors. Used for hydro-enforcement.
Source Interpretation Guidelines
None.
