Louisiana's Coast: What's at Stake

Posted: 29-May-2007; Updated: 31-Jul-2007

• Print
• Send to friend
• +

Map: Hurricane Katrina flooding
See a map showing the maximum extent of flooding in New Orleans as a result of Hurricane Katrina.

Louisiana Snapshot

Coastline:* 397 miles (6)

Tidal shoreline:* 7,721 miles (6)

Coastal population: 1.4 million (31 percent of the state's total population) (7)

Percentage of land less than 5 feet above sea level: Almost 22 percent (9,546 square miles) (8)

Property value of Gulf Coast counties: Approximately $209.3 billion (9)

Storm history since 1992: See a list of tropical storms and hurricanes that have had a direct impact on Louisiana since 1992.

* Coastline refers to the general outline of a state's sea coast; tidal shoreline refers to the coastline, as well as offshore islands, sounds, bays, rivers, and creeks measured to the head of tidewaters or to a point where tidal waters narrow to a width of 100 feet.

The destruction wreaked by Hurricanes Katrina and Rita in Louisiana was a humanitarian disaster of nearly unprecedented proportions in the United States. Nearly a year later, we have only begun to understand the repercussions of these storms on Louisiana's culture and unique way of life.

Before the 2005 season, Louisiana's Gulf region was home to 1.4 million people (1). Petroleum and chemical industries brought in annual revenues exceeding $60 billion. The state's bounty of wildlife and fish accounted for 20 percent of the nation's commercial fisheries harvest and contributed over $3 billion to the state's economy (2). Tourist dollars in Louisiana reached nearly $10 billion and supported 121,000 jobs (3).

The 2005 hurricane season changed everything.

The Gulf's fishing industry is just one example: Thousands of fishing boats were sunk or smashed beyond repair; others suffered damaged trawl gear or nets. Docks, fish processing facilities, ice plants and freezers were lost or wrecked. Losses to seafood production and damage to infrastructure reached well into the billions of dollars.

While the 2005 season stands out, Louisiana has a long history of hurricane damage. See a list of hurricanes and tropical storms since 1992 that have done damage to the state.

Storm surges and sea level rise still pose great threat

As Hurricanes Katrina and Rita showed, the 9,546 square miles of land close to sea level (4) are especially vulnerable to storm surges—highly destructive, moving crests of water that often cause the bulk of the damage in a high-category storm.

Continued sea level rise will dramatically alter the shape of Louisiana's coastline, destroying more critical wetlands and letting saltwater seep into freshwater bodies, including crawfish ponds. Higher sea levels also mean higher storm surges that reach further island.

More destructive storms are projected because of global warming

Even as we continue to rebuild the regions devastated by these storms, we must contemplate the potential for another brutal hurricane season. The likelihood that a hurricane will strike Louisiana's coast in 2006 is medium for the western half of the state and high for the eastern half (5).

As global warming continues, this already hard-hit region will be at even more risk. Recent studies show that hurricanes are becoming more powerful—for example, there are twice as many Category 4 and 5 hurricanes today than there were 35 years ago. This trend is expected to continue as global warming gets worse. For coastal residents, another alarming consequence of global warming is sea level rise, which will affect storm surges. These powerful, fast-moving walls of water can devastate coastal communities, taking lives and destroying property. Higher sea levels will mean higher storm surges that reach further inland.

No map of potential storm surge could be as vivid as the images of Louisiana residents stranded on the roofs of their homes that had been swallowed by water. Yet, knowing the vulnerable areas of a coast or a city is vital to better protect residents.