The National Hydrography Dataset The Watershed Boundary Dataset

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• U.S. Geological Survey - the NHD represents the nation’s surface water features and drainage network

• U.S. Forest Service- additional streams and other features provided as NHD stewards

• Environmental Protection Agency – data on impaired waters (red lines)

• U.S. Army Corps of Engineers - dams (red dot)

• U.S. Fish and Wildlife Service - data on streams flowing through culverts (yellow symbols ) and waterfalls (orange dots), which were assembled by the State of California

NHD as a framework for a water information system

Dams, culverts, and waterfalls can act as barriers to fish passage; the USFWS and others use these data to support studies to improve fish migration to spawning grounds

What is the National Hydrography Dataset? Essentially the surface water features found on topographic maps

The NHD organized into drainage units

Creating the Watershed Boundary Dataset

Integrating data to better understand the landscape

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Using GIS to visualize the data

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The spatial view of streams

The network view of streams

The nation’s hydrographic network using The National Map

- a 7.5-million mile network

Streams – Creating the fundamental network

Swan Creek

Perennial

Intermittent

Ephemeral

Flow Direction – Providing intelligence to the data

Navigation – The basis for analysis

Navigation – Where does a toxic spill go?

Reach 14010002000421

Reach 14010002003345

Linear Referencing – Stream “Reaches”

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75 25

14010002000421

Linear Referencing – Stream addresses

USGS Streamgage 09050000

Address: Reach – 14010002000421 Measure – 19.8392

Coordinate 106 05 13.955 W 39 32 43.472 N

Linear Referencing – Data “Events”

Connecting the streamgage to the network

Streamgage

Dam

Blue River Artificial Path (Blue River)

Green Mountain Reservoir

The NHDPlus – Synthesizing information

Medium Resolution NHD

High Resolution NHD

Local Resolution NHD