New Orleans. It’s got a colorful history. Geology there is even more colorful. Below is a pretty bad map of the city, but it is important because it shows the major neighborhoods of the city, so when I get into the geology of the city, it starts to make sense.
Here is a better view of the whole area, but it shows flooding 2 weeks after the storm. But we are getting ahead of ourselves here. I just have it so you can see the whole area.
The French Quarter was settled first. FQ, Arts, Bywater, and the CBD are all on the ancient flood levee, created by the river. It’s the highest area, so it doesn’t flood. Elevations are still below 10 feet, but much better than the rest of the town. North of all that, and south of the lake, it was all tidal marshes. Every summer, grasses, reeds, and other plants would grow. In the winter they all died. In the spring flood, these plants would be covered with 6 inches of silt from the flooding Mississippi River. Wash, rinse, repeat for millennia. As the peat gets pushed down by subsidence (the weight of the dirt on top), it slowly gets firmer. There is no bedrock for miles under the city of New Orleans. So now you have an alluvial basin of a city built of layers of jello and pudding. It grows to about 4 feet above sea level. New businesses and new housing need to be built come early 1900’s. Out to the swamp to drain and clear it. Now add concrete foundations, levees, roads and that weight takes a toll. In the 1980’s before GPS, surveying in the NO area was near impossible. The concrete benchmarks were sinking into the muck. The city was subsiding at almost an inch a year in some places. The silt and plants cycle had been destroyed and the water pumped out. New Orleans had become a bowl between the lake and the river. It’s still so bad, one of my professors still teaches a class on how to use the sophisticated benchmarks for the city to get the proper elevation.
The outer areas of the city that were developed in the 1900’s before air conditioning were quaint places to live until the newer areas with central air were built in the 1950’s. The older houses became the slums and ghettos. The Ninth Ward (pronounced “night wad”), parts of Uptown and Carrollton, and Gentilly all became slums. In the Ninth Ward, people sitting on their porches could look up and see the boats pass overhead on the river. Never made sense to me, living 10 feet below sea level, up against the river. But the housing was cheap, and the gov’mint paid for it.
Now here’s where many would call me racist. But it’s the truth. New Orleans and surrounding area has 1.2 million people in it August 1, 2005. 80% is black. Easily half to 2/3 are on welfare. It’s an extremely poor town. It’s a dying town. Their waterworks is piss poor. Remember the settling ground? Imagine lead and steel pipes under all that. Due to the saltwater intrusion, NO gets its water from the Mississippi River. Yes, the river that 38 states dump their sewage in. Yum. In NO, there is a sewage treatment plant across the river from the water intake pipe. 30 or 40 miles upstream at Waterford 3 nuclear plant, the EPA allows them to dump water taken from the river to cool the coolant pipes back into the river without treatment.
The levee system. Man, they found a big enough cross after the storm to nail the US Army Corps of Engineers (USACE) on. But after all the flooding of Hurricane Betsy from 1964 (My grandmother told me the story about the coffins floating down the street from the cemetery and the hundreds of people that climbed into their attics to avoid the rising waters, but died from not bringing an axe to make a hole and the rising water drowned them all.), the USACE decided to upgrade the levees to something better.
The 2005 levees were designed in the mid-sixties and built by the USACE. From what I understand from questions I asked when our engineering club at LSU toured the USACE center in New Orleans in 2008 (we picked up 10 engineering students from VA Tech and was sponsoring them for their first football game after the shootings—most of the shootings were in the Engineering building. Another story for another time), the USACE built the levees and turned over the operation and maintenance over to the New Orleans levee board. ‘Nuff said right there. NO is so corrupt, it makes Chicago and D.C. look pristine. Entire cemeteries vote in every election and no one can so anything about it. Anyway, the levee board is a plum assignment, if you can get on board. In the 40 years or so, they managed to plant trees on the levee, do no maintenance, build parks, marinas, and other money making ventures. From what I heard, they picked someone’s brother as the engineer to verify the levees when they needed them.
Remember a while back about the city and marsh and pumping of water and subsidence? It goes for levees, too.
While I give you a good foundation about the city and the causes of its’ demise, there are a few more points to remember:
· Since most of the town is below sea level, and the levees are above sea level, you have to pump the stormwater up and over the levees. Most of these pumps are over a hundred years old. Still really well maintained. But can only pump one inch of water out of the city an hour. NO gets 60+ inches of water a year. Hurricanes like Katrina can dump up to a foot an hour if it is bad enough. These pumps are usually manned, and are powered by various means. If backup systems fail and the pumps get submerged.... no more pumping.
· The Mississippi River is 95.0 miles long at the French Quarter. USACE built the Mississippi River Gulf Outlet (MRGO or Mr. Go) in 1965 to shorten it and to make it a straight line rather than the meandering path the river usually takes. The saltwater path killed a lot of the swamp vegetation and made a narrow path much wider.
· From what I read, the city has to declare an emergency and ask the governor for assistance from the National Guard. The governor has to release the National Guard troops to the President before he can declare an emergency. I may be confused on a bit of this, but remember that Louisiana is the only state under Napoleonic Code, so lots of our laws are screwy. Regardless, Nagin was a Democrat, and so was our governor Blanco. And Bush was Republican.
So where was I? Oh, yes, August 28, 2005. I’m prepped, my grandparents have evacuated to my dad’s house north of Houma, LA, and the streets are packed with people either finishing their preps, evacuating north, or coming into to town, evacuating from the south.
Now I have to mention, if you have ever been in a hurricane, the 24 hours before landfall are the calmest, clearest, most beautiful days you can imagine. Not a cloud in the sky, humidity is low, and little wind. But we all know that has to change, and change in a hurry.
As the sun set, the clouds started rolling in. I will wax philosophic for a moment on them, because if you’ve never experienced it, hurricanes are the closest a weather system will ever be to a living organism. The clouds move very fast, and in a circle, and all together. I will try to find my pics this weekend, but they do no justice. I have a picture of the clouds in downtown Baton Rouge, just before sunset, when the sun is low enough to reflect off the bottom of the clouds. By now, the storm is probably 400 miles wide, all spinning counter clockwise. All in one fluid motion. Really, if you have the chance, watch video of the clouds. It is both a breathtaking and terrifying moment it’s arrived and you are stuck until it passes.
By now, it’s 10pm, Sunday August 28th. It’s project to hit New Orleans by 10 am tomorrow. I check my preps once more, locating them closest to my bed, so I can grab them in a hurry if I have to bug out. I’m on the second floor, corner apartment of a brick building. I feel safe knowing I’m the top floor and have two window for egress if necessary. My roommate has taken off to go the neighbors to enjoy one of the many hurricane parties. They can’t possibly stay up for the next 24 hours to see the whole storm and drink like that. I decide to wake up early to be rested and see the storm pass overhead. The wind is slowly picking up to about 30 mph from the south and I know in the morning it’ll be 80+ from the east, then the north as the storm passes us. Time to hit the rack.