new orleans - york universitynew orleans became a vital commercial shipping centre for the entire...

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SC/NATS 1840, Science and the Environment SC/NATS 1840, Science and the Environment –– V New OrleansV New Orleans 11

New Orleans

A disaster waiting to happen –that happened


The Great Mississippi River

“Mississippi” means the “Father of Waters” in Algonquin.The river is 3,779 km long – the second longest river, after the Missouri, in the United States. It begins in Minnesota, and snakes its way south to the Gulf of Mexico, into which it empties in Louisiana.


The great water artery of the United States

From Minnesota to Louisiana it is joined by the Minnesota River, the Illinois River, the Chippewa, Black, Wisconsin, Saint Croix, Iowa, Des Moines, and Rock rivers.At St. Louis, it is joined by the Missouri River, draining the Great Plains to the west. At Cairo, Illinois., the Mississippi is joined from the east by the Ohio River.

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A river constantly extending itself

South of Cairo, Illinois, the river flows in a low valley that was once part of the Gulf of Mexico, but over centuries has been filled in by sediment dumped by the river.At present, the Mississippi River has extended itself 1000 km further downstream and continues to grow by 100 m per year.


Louisiana

In 1541, the first Europeans saw the river inland. In 1682, Robert Cavalier, the Sieur de La Salle, reached the mouth of the Mississippi and claimed the whole valley, from Minnesota to Louisiana, for France, naming it in honour of Louis XIV.


France establishes a colony

In 1718, in order to protect France's holdings in the New World, King Louis XIV dispatched Pierre LeMoyne, Sieur d'Iberville, to Louisiana to find suitable places to build forts. Iberville established settlements along the Gulf Coast, notably Biloxi, and at several places up the Mississippi River.Iberville returned to France, leaving his brother, Jean Baptiste LeMoyne, Sieur d'Bienville, in charge.

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La Nouvelle-OrléansOne of the Bienville's first duties was to lay out a town on the Mississippi River, its location to be “thirty leagues up the river…which one may reach by the river and by Lake Pontchartrain.”The area chosen by Bienville was at the point where the river makes a wide crescent, was closest to the lake, and possessed an easy portage route along Bayou St John, a small stream that flowed into the lake to the north. It was named for the regent of France, Philippe II, duc d'Orleans.


A site chosen for trade

The site for the new town was where French fur trappers and traders had already set up a community to deal with native Americans and have easy access to ocean-going ships.It was on a rare bit of natural high ground along the flood-prone banks of the lower Mississippi.


Ignoring warnings even then

Even then, Bienville’s engineers warned against founding a city in swampland surrounded by a mighty river that floods regularly and a huge lake to the north.

Above, typical swampland. At right, modern New Orleans, showing the river snaking through the city and the lake to the north.

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The French Quarter

The original city was laid out in a rectangular pattern with a central square (pictured) surrounded by a church and government offices.This original area is the present French Quarter, the main tourist area of the city.

This is the highest ground in the city.


From France to Spain and back

The vast territory of Louisiana remained a French colony until 1763, when it was transferred to the Spanish Empire.In 1800, Spain ceded it back to France in a secret treaty.Napoleon Bonaparte had envisaged a great French empire in the New World, but changed his mind as he lost thousands of troops to Yellow Fever in Haiti and needed funds to support his wars in Europe.

In 1803, he offered to sell the entire Louisiana territory to the United States.


The Louisiana purchase

US President Thomas Jefferson, already concerned about access to the Mississippi, jumped at the chance to buy the whole territory.In a stroke, the U.S. doubled its size in 1803.

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The river highway

With the advent of the steamboat in 1812, the Mississippi and the other rivers connecting to it became major thoroughfares for commerce.The city of New Orleans became a major port, handling over 6000 vessels a year.

Second largest port in the USA.Fourth largest port in the world.


The city grew and thrived

New Orleans became a vital commercial shipping centre for the entire U.S.Goods came to New Orleans by land, downriver, and up from the Gulf of Mexico.


The Big Easy

The city became known for its relaxed lifestyle and its distinctive Dixieland Jazz. (Above: Louis Armstrong and the Preservation Hall Jazz Band.)

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“Let the good times roll…”The distinctive cuisine, architecture, music, and warm climate made New Orleans a natural destination for conventions and conferences.In the post World War II era, it has become one of the major tourist centres in the U.S.


Population growth & urban sprawl

Along with commercial success came population growth and expansion of residential development into what had been uninhabitable swampland surrounding the old city.

1726

2005


A city built below sea level

None of the city of New Orleans is on ground high enough to be protected from even minor flooding. Only the French Quarter and other land near the river bank are close to being at sea level. Newer parts of the city are up to 20 feet below the level of the Mississippi River or Lake Pontchartrain.

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The saucer


LeveesBecause much of the city is below the high water level of the Mississippi River, a system of levees has been in place almost from the founding of the city.Levees are barriers, typically small hills, that run the length of the river bank and keep water from flooding into the surrounding land.The original levees in New Orleans were only 1 meter high and did not prevent flooding.


A few steps up for safety

All the older homes are built a few feet above the ground and have no basements or cellars. Otherwise they would flood even at heavy rainfalls.

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Cemeteries

One of the distinctive New Orleans practices is to bury the dead in mausoleums and crypts built above the ground, since the water table is struck almost immediately.


Lake PontchartrainLake Pontchartrain forms a natural boundary to the city on the north.

This is a not a “great lake,” but very large for the region: 300 square miles.In 1956, a 24-mile bridge was built across it in the shorter direction. It is the longest over-water bridge in the world.

Lake Pontchartrain empties into the Gulf of Mexico through two narrow outlets. A canal and a bayou connect the lake to the city’s water drainage system.


The flood of 1927

Though New Orleans has endured many floods, a great disaster occurred in 1927.

Heavy rains pounded the central basin of the Mississippi in the summer of 1926. By September the Mississippi's tributaries in Kansas and Iowa were swollen to capacity. On New Year's day of 1927 the Cumberland River at Nashville topped levees at 17 meters. As the flood approached New Orleans, 30 tons of dynamite were set off on a levee upstream of the city and sent 7,000 m³/s of water pouring through. This prevented New Orleans from experiencing serious damage but destroyed much of the marsh below the city.

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More leveesA formal system of levees along the Mississippi in New Orleans was begun in 1890, but levee building was vastly expanded and more fortified after the 1927 flood.Levees are not dams. They are designed to stand up only for a few days of flooding, not a constant pressure of water.The levees built along the Mississippi by the Army Corps of Engineers are quite strong and can withstand severe pressure.


Levees on the Lakeside

When more and more swampland was cleared for residential development near Lake Pontchartrain, levees were built along the lake to forestall flooding from rising lake waters.These levees were not build to the Corp of Engineers standard.


PumpsBecause the city is below the level of the waters surrounding it, a complex system of pumping stations works constantly to pump water out to sea through the lake.Without these pumps working constantly, water would back up at any time.

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Hurricanes New Orleans is brushed by a hurricane about once in four years and suffers more serious hits on average about once in 14 years.

In 1965 Hurricane Betsy drove water over the levees and flooded the city, overwhelming the pumps.In 1998, Hurricane Georges breached the seawall at the lake and flooded homes in that area.


Hurricane Katrina

Hurricane Katrina developed from a tropical waveabout 280 km east of the Bahamas. The hurricane strengthened to Category 1 before making landfall in Florida on August 25, 2005. Katrina moved southwest across Florida and west into the Gulf of Mexico, where it intensified rapidly to Category 5.


Hurricane Katrina, 2

In the early morning of August 29, Katrina made its second landfall as a Category 4 storm featuring 230 km/h winds, and its eyewall passed over the eastern edge of New Orleans as the hurricane made its way to water once again. A few hours later, it made landfall for a third time near the Louisiana/Mississippi border with 200 km/h Category 3 winds.

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Hurricane Katrina, 3As the hurricane approached New Orleans, the mayor issued a mandatory evacuation order.

Highways out of the city were routed for one-way outbound traffic.

For those unable to leave, the Superdome stadium was set up as a temporary shelter.

About 11,000 people sought shelter in the stadium. During the hurricane two holes were torn in the roof of the stadium.

A National Guard truck delivering emergency supplies to the Superdome.


Hurricane Katrina, 4Hurricane Katrina was the third most intense hurricane on record to hit the United States. New Orleans did not suffer a direct hit. New Orleanians thought they might escape the worst of the damage.As Katrina moved ashore for the third time, it veered to the east and passed over the resort towns, Gulfport and Biloxi, which were largely destroyed.

At Biloxi, the storm surge that hit the coast was 10 meters high—the highest ever recorded in the U.S.


Hurricane Katrina, 5

However, the real damage was yet to come.The particular approach of Katrina drove water into Lake Pontchartrain, raising it to dangerous levels.Two levees on the lake broke and the city was flooded.In a few hours 80% of New Orleans was underwater.

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Technology trap

New Orleans relies on its pumps to clear the city of water.

The pumps work by pumping water into the lake.

With the levees breached, pumping into the lake would accomplish nothing.Moreover, the city lost electrical power, so the pumps were out of commission.

None of the emergency solutions could do any good.


An unprecedented disaster for the U.S.

With most of the city inundated with bacteria-laden water, no means to drain it, and no power, life was untenable. Those who had taken shelter in the Superdome were bused to Houston to take up residence in the Astrodome stadium. Those who evacuated under their own power were prevented from returning.Looters remained. The city fell into lawless chaos. Residents who chose to remain behind were in peril.Hundreds have died.


Why was the city so vulnerable?The risk of devastation from a direct hit was well documented.

In 2002, the New Orleans Times-Picayunenewspaper ran a series on the risk. "It's only a matter of time before South Louisiana takes a direct hit from a major hurricane. Billions have been spent to protect us, but we grow more vulnerable every day." Scientific American covered the topic thoroughly in an October 2001 piece titled "Drowning New Orleans."

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Why was the city so vulnerable?, 2

Aside from the inevitable dangers to New Orleans due to its location, it was in greater danger because adequate preventive measures had not been taken.

Lakeside levees had sunk by four feet and were not repaired.A repair to the levee at the 17th St. Canal (site of a major breech) was incomplete when Katrina struck.Funding had been cut to 1/6 the amount needed for a major federal flood control project in the area.


The immediate versus the preventative

It is widely believed that federal money that was to be spend on flood prevention was diverted to the support of the war in Iraq and homeland security.In any case, for many years money for infrastructure to cope with a possible risk has been used instead for an immediate priority.

This is but the most recent example of a common practice throughout the history of civilization.

new orleans - york universitynew orleans became a vital commercial shipping centre for the entire...

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