Unintended consequences

September 14, 2005|By Mike Tidwell

THE BUSH administration is ignoring reports from its own agencies that say every coastal city in America - from New York to Los Angeles - could become a New Orleans within a generation or two.

The flooding, storm damage, death toll and economic ruin we are seeing in the Crescent City could become an annual occurrence in some other U.S. city spread across some other American coastline.

Why? Because of the phenomenon known as the "law of unintended consequences." In Louisiana, we built huge levees that for centuries kept the lower Mississippi River from flooding. The unintended result was that the entire coast of Louisiana, including New Orleans, began rapidly sinking, dropping 2 to 3 feet in the last century alone.

Worldwide, a different dynamic but with similar catastrophic potential is playing out. Year after year, we burn massive amounts of fossil fuels - oil, coal and natural gas. The result is that we've profoundly warmed our planet's atmosphere. This global warming, according to the administration's own reports, will lead to a rise in sea level of 1 to 3 feet worldwide by 2100.

Here's the crux: Whether the land sinks 3 feet per century (as in New Orleans) or the oceans rise 3 feet per century (as in most of the rest of the world), the result is the same for America's 150 million coastal residents and the 3 billion shoreline inhabitants worldwide: record storm surges, inundated infrastructure, massive human relocation, economic disruption, untold suffering and death.

In all the recent coverage, the media seem to have uncritically accepted the very weird fact that New Orleans lies below sea level. Why is it below sea level?

Because of the levees. The huge earthen river dikes that have kept the city dry and inhabitable for 300 years have also created the giant bathtub we now see on TV that is full of putrid water.

Every great river delta in the world is shaped by two unforgiving geological phenomena. The first involves flooding. The annual overflow of the sediment-rich Mississippi River is what created Louisiana's vast deltaic coast, depositing water-borne sediments and nutrients flowing down from two-thirds of America over the past 7,000 years.

The second major deltaic feature is "subsidence," or sinking. Those sedimentary deposits of alluvial soil are extremely fine and unstable. Over time, they compact, shrink and sink. Historically along the Louisiana coast, it was new flooding, new annual deposits of sediments, that counterbalanced the sinking and, in fact, led to net land building.

But by corseting the river with levees right out to the precipice of the Gulf of Mexico's continental shelf, we are left only with subsidence. Every day, even without hurricanes, 50 acres of land in coastal Louisiana turns to water. Every 10 months, an area of land equal to Manhattan joins the gulf. It is, hands down, the fastest disappearing land mass on earth.

This is why the flooding from Katrina happened.

When French colonists first settled Louisiana 300 years ago, there were vast tracts of dense hardwood forests between what is today New Orleans and the Gulf of Mexico. There were extensive fresh water marshes and endless saltwater wetlands and a formidable network of strong barrier islands.

Today, all that land is essentially gone. It has turned to water. Because of the levees and the law of unintended consequences, New Orleans is a sunken, walled city essentially jutting out like an exposed chin toward the fast-approaching fist of the gulf. Had Katrina struck 200, 100 or even 50 years ago, the destruction would not have been the same. In 2005, there simply were no land structures left to slow Katrina's sledgehammer blow.

The good news is there is a plan to re-create much of that lost land. A detailed restoration scheme has been on the table since the 1990s to literally re-engineer the coast, according to Louisiana Gov. Kathleen Babineaux Blanco. The plan is to build up to a dozen dam-like control structures right into the levees of the Mississippi. These would then release the sediment-thick water into canals or pipelines that would surgically direct the liquid soil toward the barrier islands and the buffering marshlands that need immediate restoration.

This so-called "Coast 2050" plan will take many years to fully implement, but the cost is ridiculously cheap at $14 billion. That's just six weeks of spending in Iraq or the cost of Boston's "Big Dig." Yet tragically, like Louisiana's pre-Katrina requests for federal help to bolster insufficient levees in New Orleans, the Bush administration has spent more than four years repeatedly refusing even modest investments in the larger coastal restoration efforts.

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