Elevation-Derived Hydrography READ Rules: Dam/Weir
A Dam/Weir is a barrier constructed to control the flow or raise the level of 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.
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 7).
Special conditions: none.
Table 7. Dam/Weir Representation Rules.
| Kind of feature object | Area | Shortest Axis | Longest Axis |
| 0-dimensional (point) | -- |
less than 40 feet (for use on lines) |
greater than 240 feet (73 meters) |
| 1-dimensional (line) | -- | less than 40 ft (for use on polygon waterbody features) | greater than 240 feet (73 meters) |
| 2-dimensional (polygon) | -- | greater than 40 ft (for use on polygon waterbody features) | greater than 240 feet (73 meters) |
Data Extraction
Capture Conditions
If dam/weir is greater than or equal to 240 feet (73 meters) along the longest axis,
then capture.
Attribute Information
FClass 1—Hydrography feature defined within the collection criteria of the elevation-derived hydrography specifications.
FCode 46800—Drainageway (flowlines delineated where terrain modelling indicates potential headwater drainage, but no channel is detectable).
EClass 2—Linear hydrographic features that follow the elevation surface.
Source Interpretation Guidelines
None.
