Wyoming’s NHD and WBD Maintenance and Enhancements

NHD/WBD Stewardship ConferenceMarch 29-30, 2012New Orleans, Louisiana

Paul CaffreyWyoming Geographic Information Science Center(WyGISC)

Overview

What have we done

What have we not done

What next

Discussion/Questions

State Events

Dams

Gaging stations

Diversion structures

State Dam/Gaging Station/Diversion Structure

1,458 new Dam Events were added that were not

originally captured in NHD

56 existing Dam Events were spatially corrected

(these dams were originally captured in NHD, but

not at correct location/point along NHD Flowline)

90 new Gaging Station Events were added

24 new Diversion Structure Events with radio

telemetry

GNIS & NHD

Performed a check to locate and correct

1. Missing

2. Misspelled

3. Misplaced

named features for the streams, rivers, lakes and point features in Wyoming

GNIS & Hydrographic Features

GNIS & Hydrographic Features

GNIS & NHDFor the NHD, the task for assigning names to water features using the GNIS was a pretty straightforward process. Unfortunately, discrepancies and errors persist due to:

low resolution GNIS vectors and points and coordinate errors

interpretative mistakes made during GNIS conflation process while creating the hydrographic data.

Example: GNIS line vectors

GNIS updates made to Wyoming’s NHD

Streams:

97 NHD Flowlines (originally unnamed) received

GNIS names and ID numbers

129 NHD Flowlines received corrections to their

GNIS name and/or ID number

19 are unable to be corrected due to inherent GNIS

coordinate errors and other issues

Lakes/Reservoirs:

638 NHD unnamed Waterbodies received GNIS names

and ID numbers

118 NHD Waterbodies received corrections to their

GNIS name and/or ID number

123 WB features missing geometry have been

captured

Lakes/Reservoirs (cont.):

34 NHD Waterbodies with missing or incorrect

GNIS names/IDs are still in need of correction

294 are unable to be corrected due to inherent GNIS

coordinate errors and other issues

Springs/Waterfalls/Rapids:

• 206 missing features currently being captured, soon

to be added to NHD Point geometry

• 236 NHD Points with missing or incorrect GNIS

names/IDs in need of correction

• 62 not corrected due to inherent GNIS coordinate

errors

WBD- Hydrologic Unit Name Updates 151 watersheds (10-digit units) have received an

updated HU_10_NAME 52 of these are shared with one or more bordering states and are

awaiting coordination

1,309 subwatersheds (12-digit units) have received

an updated HU_12_NAME 153 of these are shared with one or more bordering states and

are awaiting coordination

NHD/WBD Pour Points

NHD/WBD Pour PointsPrimary purpose for creating the True Pour Point features was twofold: 1) To capture the most accurate geographic location of

all WBD outlets/stream drainage points using the 2009 NAIP

2) To assess the horizontal accuracy and vertical alignment discrepancies between a stream's current pour point location and its WBD and NHD counterpart• Pour Point/NHD average offset distance

equaling ~70 meters• Pour Point/WBD average offset distance

equaling ~121 meters.

NHD/WBD Pour Points 2,327 True Pour Points were placed at the most

horizontally accurate/current geographic location of

drainage points for all streams at WBD outlets

The number of True Pour Points exceed the

number of WBD outlets (2,195), due to multiple

drainage points from complex stream channels

2,192 NHD Pour Point Events were indexed to the

top of all NHDFlowline reaches draining from WBD

outlets

NHD/WBD Pour Points

Acknowledgements-USGS/NRCS

NHD/WBD Team

Barb Ray, WY Geo-Liaison

Wyoming BLM:

State Office, Rick Schuler

Wyoming State Engineers Office

Jason Feltner

Wyoming Board of Geographic Names

UW/WyGISC Team

Pat Madsen, GIS Specialist

Discussion

Questions