NHDWaterbody

 

NHDWaterbodies contain regions representing areal NHD hydrographic waterbody features. Some Waterbody features such as LakePond, Reservoir, and Estuary must have a reachcode. SwampMarsh may have a reachcode. Ice Mass and Playa do not have reachcodes.

The NHDWaterbody feature class contains polygon features that

may or may not have a reach code.

 

See a complete list of Fcodes for hydrography features.

 

The attributes associated with NHDWaterbodies are as follows:

Field Name

Definition

Comments

Permanent Identifier

Global ID and GUID data types store registry style strings consisting of 36 characters enclosed in curly brackets. These strings uniquely identify a feature or table row within a geodatabase and across geodatabases. This is how features are tracked in one-way and two-way geodatabase replication.

 

FDate

Date of last feature modification.

 

Resolution

Source resolution.  Currently NHD is available as separate resolutions.  Plans are to develop a single-resolution database holding the highest resolution data with tools to allow for generalization

Domain of values:

Local >1:12,000

High 1:24,000/12,000

Medium 1:100,000

GNIS_ID

Unique identifier assigned by GNIS, length 10.

GNIS_ID = “null” if no name associated with the feature

GNIS_Name

Proper name, specific term, or expression by which a particular geographic entity is known, length 65.

GNIS_Name = “null” if no name associated with the feature

AreaSqKm

Area of areal feature based on Albers Equal Area, length 8.

Computed

Elevation

The vertical distance from a given datum.

Stage of the water elevation is encoded in the FCode.

ReachCode

Unique identifier composed of two parts.  The first eight digits is the subbasin code as defined by FIPS 103.  The next six digits are randomly assigned, sequential numbers that are unique within a subbasin, length 14. 

Required for all NHDFlowlines.

NHDWaterbody and NHDPoint feature classes allow reach codes, but does not require them.

WBArea_Permanent_Identifier

Global ID and GUID data types store registry style strings consisting of 36 characters enclosed in curly brackets. These strings uniquely identify a feature or table row within a geodatabase and across geodatabases. This is how features are tracked in one-way and two-way geodatabase replication.

 

FType

Three-digit integer value; unique identifier of a feature type.

 

FCode

Five-digit integer value; composed of the feature type and combinations of characteristics and values.

 

Shape_Lenth

 Length in meters

All features should have a +integer value

Enabled

Created when Geometric Network is built

All features should be set to True (From the database).

New or modified features will have a Null value until network is rebuilt.