National Hydrography Dataset (NHD) Flowlines

Abstract

NHD Flowlines consist of routes that make up a linear surface water drainage network. Flowlines have a reach code and a measure, allowing for the establishment of upstream/downstream relationships. This network allows for powerful analysis and modeling capabilities. Each Feature type is attributed with descriptive information by an Fcode.

Purpose

The NHD was created to assist scientists in modeling hydrologic features and is also useful for cartographic mapping purposes. The geometric features that came from the USGS DLG files, combined with the flow direction, reach codes, and other attributes taken from the EPA RF3 file, make the NHD a powerful modeling tool.

Time Period of Content

Beginning date: 1990s
Ending date: 2016

Publish Date

2016-05-11

Originator

USGS, Florida Water Management Districts, Florida Department of Environmental Protection

Publisher

Florida Department of Environmental Protection

Theme Keywords

hydrography, water, lakes, streams, rivers, estuaries

Place Keywords

Florida

Source Scale

1:24,000

Horizontal Accuracy

Estimated to meet 1:24,000 National Map Accuracy Standards (+/- 40 feet)

Vertical Accuracy

If the source for elevation is 7.5 minute topo map, estimated to be one half of a contour, or +/- 2.5 feet.

Process Steps

Format

ESRI File Geodatabase

Format Details

Projection

Albers Florida HARN

Field Names

permanent_identifier = Unique ID

fdate = Date of last feature modification.

resolution = Source resolution. All values = 2

Code	Description1	Description2
1	Local	>1:12,000
2	High	1:24,000/12,000
3	Medium	1:100,000

gnis_id = USGS Geographic Names Information System (GNIS) ID

gnis_name = USGS Geographic Names Information System (GNIS) Name

lengthkm

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.

flowdir = Direction of flow relative to coordinate order.

wbarea_permanent_identifier

ftype = 3-digit feature code. (Integer)

Code	Description
334	Connector
336	Canal/Ditch
420	Underground Conduit
428	Pipeline
460	Stream / River
558	Artificial Path
566	Coastline

fcode = 5-digit feature code. Extra two digits provide a more detailed description of the feature. (Integer)

enabled = Created when Geometric Network is built. All features should be set to True. New or modified features will have a Null value until network is rebuilt.

parent_feature

Distribution Info

http://geodata.dep.state.fl.us/

http://publicfiles.dep.state.fl.us/otis/gis/data/FLORIDA_NHD.zip