Texas Height Modernization Dr. Gary Jeffress, RPLS Texas Spatial Reference Center National Height Modernization Partner Meeting NOAA Gulf of Mexico Disaster Response Center Mobile, Alabama – April 2014

Recent Projects GPS Precise Network Observations Along the Texas Gulf Coast – TCOON Tide gauge Benchmarks – Historic USACE tidal benchmarks – Texas CORS – GPS-able NGS first & second order Benchmarks A total of 72 network sessions and 153 stations observed (Adjust and Pages) All stations Bluebooked Funded by US Army Corps of Engineers

GPS Precise Network Observations Along the Texas Gulf Coast

GPS Precise Network Observations Along the Florida Gulf Coast

CORS on Tide Gauges Florida Pensacola, FL

CORS on Tide Gauges Florida Fernandina, FL

CORS on Tide Gauges Florida St. Petersburg, FL

CORS on Tide Gauges Florida Cedar Key, FL

CORS on Tide Gauges Texas Existing CORS 4 (USACE 2, NERRS 1, USFW 1) Proposed Sentinel CORS 4 (USFW) Proposed Height Mod. CORS 5 TOTAL 13 Sentinel

The need for accurate Elevation in Texas Austin, 1991 Houston, 2001 Lives are lost and $Billions of property are lost.

National Flood Statistics (2001) From

Licensed Surveyor’s Role

13 Up to 80% of these benchmarks have disappeared Answer: The data are old and subject to change and destruction. Why are Elevations so bad?

Why are Elevations Important? An Example from Galveston Bay, Texas

An Example from Galveston Bay, Texas From Google Street View

An Example from Galveston Bay, Texas X From Google Maps

An Example from Galveston Bay, Texas X

X X

FF = Finished Floor Level FF = feet FIRM September 1999 Zone AE EL 12 = feet FIRM September 2012 Zone AE EL 15 = feet

An Example from Galveston Bay, Texas Surveyor’s Elevation Datum

Flood Insurance Quote

For Sale $1,028,697 ?

Thank you for listening.