Katrina poised to destroy New Orleans

Hurricane Katrina is nearing the Louisiana coast, bringing with it a vast fury and power that has the potential to destroy the New Orleans metropolitan area:

Hurricane Katrina, one of the most powerful storms ever to threaten the United States, bore down on the Gulf Coast on Sunday, sending hundreds of thousands of people fleeing the approach of its 160-mile-an-hour winds and prompting a mandatory evacuation of New Orleans, a city perilously below sea level.

There is a major concern about what the hurricane will leave behind:

When Hurricane Katrina hits New Orleans on Monday, it could turn one of America's most charming cities into a vast cesspool tainted with toxic chemicals, human waste and even coffins released by floodwaters from the city's legendary cemeteries.

Experts have warned for years that the levees and pumps that usually keep New Orleans dry have no chance against a direct hit by a Category 5 storm.

That's exactly what Katrina was as it churned toward the city. With top winds of 160 mph and the power to lift sea level by as much as 28 feet above normal, the storm threatened an environmental disaster of biblical proportions, one that could leave more than 1 million people homeless.

It's a massive environmental disaster just waiting to happen:

Experts have warned about New Orleans' vulnerability for years, chiefly because Louisiana has lost more than a million acres of coastal wetlands in the past seven decades. The vast patchwork of swamps and bayous south of the city serves as a buffer, partially absorbing the surge of water that a hurricane pushes ashore.

Experts have also warned that the ring of high levees around New Orleans, designed to protect the city from floodwaters coming down the Mississippi, will only make things worse in a powerful hurricane. Katrina is expected to push a 28-foot storm surge against the levees. Even if they hold, water will pour over their tops and begin filling the city as if it were a sinking canoe.

After the storm passes, the water will have nowhere to go.

In a few days, van Heerden predicts, emergency management officials are going to be wondering how to handle a giant stagnant pond contaminated with building debris, coffins, sewage and other hazardous materials.

"We're talking about an incredible environmental disaster," van Heerden said.

He puts much of the blame for New Orleans' dire situation on the very levee system that is designed to protect southern Louisiana from Mississippi River floods.

Before the levees were built, the river would top its banks during floods and wash through a maze of bayous and swamps, dropping fine-grained silt that nourished plants and kept the land just above sea level.

The levees "have literally starved our wetlands to death" by directing all of that precious silt out into the Gulf of Mexico, van Heerden said.

Pacific Northwest Portal continues to provide special coverage of Hurricane Katrina, and Daily Kos user DarkSyde also has an execllent diary.