NOAA 2002-R440
Contact: Glenda Tyson

NOAA News Releases 2002
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Vulnerable Routes Topic of 2002 Hurricane Season Round Table

Recent studies by the National Oceanic and Atmospheric Administration (NOAA) National Geodetic Survey Office (NGS), in partnership with Louisiana State University’s Spatial Reference Center, indicate the state’s hurricane evacuation routes are growing increasingly vulnerable to coastal storm surge and flooding. NOAA will discuss this topic at the Post 2002 Hurricane Season Round Table Discussion, held today at the Louisiana Spatial Reference Center on the campus of Louisiana State University. NOAA is an agency of the Commerce Department.

The research team conducted an intensive eight day survey of Louisiana Highway-1 (LA-1), from Raceland to Grand Isle, after reports from communities that hurricane evacuation routes were quickly becoming flooded. LA-1 is the only evacuation route for coastal areas such as Grand Isle, Port Fourchon, and for thousands of people working offshore in the Gulf of Mexico on rigs and platforms. This critical evacuation route was flooded by both Tropical Storm Isidore and Hurricane Lili.

"We need to understand the present-day heights of these roadways, determine the loss of elevation - subsidence, and predict the future subsidence threatening these routes during coastal storms,” said Charlie Challstrom, director of the NOAA National Geodetic Survey Office. “The loss of elevation in South Louisiana and the growth of open water conditions along the coast make future storms and hurricanes more likely to flood evacuation routes, coastal towns and ports, and stress flood protection levees each year.”

NOAA NGS and the Louisiana Spatial Reference Center analyzed hundreds of benchmarks across coastal Louisiana to track subsidence in many coastal evacuation routes during the last 20 to 40 years.

"What we saw was a picture of South Louisiana sinking at rates in excess of 1 inch per year in certain areas along the coast," said Dr. Roy Dokka, director of the Spatial Reference Center. "We are able to clearly see that areas like Leeville, Golden Meadow and Valentine are all areas that have subsided significantly since 1982.”

The results of these surveys will be used in preparation for the 2003 hurricane season to project future elevations of hurricane evacuation routes. This research will also help create a true picture of how southern Louisiana is subsiding and how this can be used in flood protection, evacuation route improvements, and coastal restoration work.

NOAA is dedicated to exploring, understanding, conserving and restoring the nation’s coasts and oceans. NOAA’s National Ocean Service, which includes the National Geodetic Survey, balances environmental protection with economic prosperity in fulfilling its mission of promoting safe navigation, supporting coastal communities, sustaining coastal habitats and mitigating coastal hazards.

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