Contact: Ben Sherman
NOAA News Releases 2005
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Provides Critical Update on South Louisiana Elevation Surveys

Officials from NOAA, the National Oceanic and Atmospheric Administration, announced today that new elevations for three south Louisiana parishes of St Bernard, Cameron and Calcasieu have been published. The newly-published values will lower official elevations in these parishes and establish a new network of vertical controls to serve as benchmarks.

Use of the new elevations and vertical control network is important for hurricane recovery, repair and construction efforts. Evacuation routes, restoration and hurricane protection levee projects also need to use the new elevations and control network.

"Using these new benchmarks, planners will be better able to determine road and bridge heights relative to water and ground levels from these data,” stated Charlie Challstrom, acting assistant administrator of NOAA's National Ocean Service. “They will be able to ensure that evacuation routes and shipping lanes have appropriate clearance to avoid flooding and obstructions."

NOAA plans to explain the new data points in two parish meetings over the next week. The meetings are scheduled for Monday, October 17, in Houma, La., at 1:00 p.m. in the Houma-Terrebonne Parish Engineers Office, 1860 Grand Caillou Road; Phone: (985) 873-6841, and Wednesday, October 19, in Lake Charles, La., at 10:00 a.m., in the Lake Charles Office of Emergency Preparedness, 911 Hodges Street; Phone: (337) 721-3800.

NOAA has already met with officials from FEMA and the U.S. Army Corps of Engineers to explain the new benchmarks.

The meetings are the first in a series that will be conducted to educate users on how to use new technologies available such as the Global Positioning System and NOAA’s Continuously Operating Reference Stations to provide accurate elevation reference points as the region recovers.

The new elevations are part of an ongoing state-wide effort in Louisiana to improve the accuracy of survey benchmarks and insuring they will remain accurate for longer periods. This height modernization effort was originally made in July in a New Orleans press conference.

NOAA’s National Geodetic Survey is analyzing the historical leveling data as well as new leveling and GPS surveys. They are feeding the data into updated scientific models to provide more accurate elevations on benchmarks in southern Louisiana.

NOAA has had the support and cooperation of institutions and organizations in the Gulf Coast region, especially the Harris/Galveston Coastal Subsidence District (HGCSD), in coordinating efforts to detect and measure subsidence. Many of the specifications and procedures designed for use in the Louisiana Coastal region were developed in conjunction with the HGCSD.

The Louisiana Spatial Reference Center (LSRC) was established in 2002 at Louisiana State University in response to users’ and public safety needs. The LSRC operates in conjunction with NOAA to develop and provide height modernization procedures in Louisiana as well as to share technology development with others. Congress specifically provided height modernization funding in fiscal year 2005 for the Gulf Coast states of Alabama, Mississippi, Louisiana and Texas.

NOAA officials noted it is critical that users of the elevation data apply it in accordance with new approaches being developed, and work with the Louisiana Spatial Reference Center to improve the geospatial reference system in Louisiana. While there will be fewer specific benchmarks, the overall accuracy of the heights will be maintained for longer periods.

NOAA does not predict the rates of subsidence nor determine its causes. NOAA does supply data used by the U.S. Geological Survey, U.S. Army Corps of Engineers, state agencies, academics, emergency planners, engineers, surveyors, environmental restoration efforts, and others to determine those rates.

The National Oceanic and Atmospheric Administration, an agency of the U.S. Department of Commerce, is dedicated to enhancing economic security and national safety through the prediction and research of weather and climate-related events and providing environmental stewardship of our nation’s coastal and marine resources. Through the emerging Global Earth Observation System of Systems (GEOSS), NOAA is working with our federal partners and nearly 60 countries to develop a global Earth observation network that is as integrated as the planet it observes, predicts and protects.

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