Skip to main content
U.S. flag

An official website of the United States government

National Hydrography Dataset (NHD) Data Dictionary Flowline Value Added Attribute

The data dictionary for Flowline Value Added Attribute table in the National Hydrography Dataset.


NHDFlowline Value Added Attributes table. Table derived entirely from the NHDFlowline features and the NHDFlow table values.

Name Definition Type Allow Nulls Length Domain Default Value Comments
ArbolateSumKM Sum of the lengths of all the drains that drain to the downstream end of the current drain. Double True        
DivergenceFlag If this drain is 1 branch of a flow split, 1=drain is main branch, 2=otherwise, 0= drain not a branch of flow split. Long Integer True        
DnDrainCount Number of drains immediately downstream. Long Integer True        
DnLevel Stream level of drain. Long Integer True        
DnLevelPathID Level path ID of downstream drain. Double True        
DnMinHydroSeq At a divergence, the Hydro sequence number of the minor downstream drain. Double True        
FDate Date of last feature modification. Date False 8      
FromNode Nationally unique ID for the "from" node endpoint of the drain. Double True        
HydroSeq Nationally unique sequence number that places the reach in hydrologic sequence. Double True        
LevelPathID Hydro Sequence No. of downstream drain that is on the same level path as this drain according to the DFlow Table. Double True        
OBJECTID Internal feature or event number. OBJECTID False        
PathLengthKM Distance from this drain pourpoint to its terminal drain's pourpoint according to the DFlow Table. Double True        
Permanent_Identifier A 40-character globally unique ID (GUID) value that uniquely identifies the occurrence of each feature or event in The National Map. Text False 40      
StartFlag Set to '1' if the drain is a headwater drain according to the DFlow Table, otherwise '0'. Long Integer True   NoYesDomain    
StreamLevel Drain_level of the downstream mainstem drain. Long Integer True        
StreamOrder Strahler stream order number for the drain. Long Integer True        
TerminalFlag Set to '1' if drain is a terminal drain (flows into ocean, Great Lakes, Canada, Mex. or the ground) otherwise set to '0'. Long Integer True   NoYesDomain    
TerminalPathID Hydrologic sequence number of terminal flowline. Double True        
ThinnerCode Ordinal value designed to allow selection of progressively more dense networks. Least dense network=1. Long Integer True        
ToNode Nationally unique ID for the "to" node endpoint of the drain. Double True        
UpHydroSeq Hydro Sequence No. of upstream mainstem drain. Double True        
UpLevelPathId LevelPathID of upstream mainstem drain. Double True        
UpMinHydroSeq Minimum Hydro Sequence No. of all upstream drains. Double True