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Living With The Deltaic Environment In Greater New Orleans



NOTE:  Be sure to closely examine the slides we use in class, as there are images there that are not in the notes below.


The earliest residents of the present-day New Orleans region were Native Americans.  We don't know who the earliest peoples called themselves, but we identify them by the remnants of their culture.  Though there were humans here for thousands of years (and many who visited for resources then returned to another home), we call the earliest heavily studied peoples in our area the Tchefuncte Culture (600 BC to 200 AD; patternless pottery), and those who followed Marksville (1 AD to 400 AD; inscribed designs on their pottery and developed intricate burial rituals).  We don't know what they called themselves.  

They lived simply, and moved often in response to the season (food availability), weather, and water levels.  They chose high ground, and built poll houses bedecked with palmettos.  

Tchefuncte camp

As they ate, they dropped their leavings, so we know the basics of their diets.  They ate many Rangia clams, as evidenced by their middens (the piles of shells, broken pottery, animal bones, etc.), and a wide range of animals and plant parts.  A typical midden as seen today is a mound of shells often with oak trees growing on them (it was the only high ground where an oak could survive).  The following photo of a midden is beside the Coquille Trail at Jean Lafitte National Park - Barataria Unit.

Oak Tree w midden J Lafitte 10-03


These cultures morphed into a number of tribes whose names we recognize.

Native Americans in LA Kniffen

It is easy for non-Louisianans to wonder why anyone from the "modern world" would settle in a dank, sinking subtropical area full of alligators, snakes, and insects.  Bienville chose the French Quarter area for his settlement because it met certain economic needs.  Before the settlement of New Orleans in 1718, all shipping coming down the Mississippi River and destined for Mobile had to exit the mouth of the river and sail across Breton Sound.  During good weather, this was no problem.  However, southeast Louisiana is known for its storms of various types.  These storms make a crossing of the very shallow Breton Sound very treacherous.  

It is said that Bienville landed at a point where Iberville Street meets the river today (one block east of Canal Street).  He chose this place because it was the nearest place to transfer cargo from the river to Bayou St. John, a sheltered waterway to Lake Pontchartrain.  

Trudeau Map NO

Carlos Trudeau map, ca. 1798


Once cargo was portaged to ships waiting at the head of the bayou, it was shipped down the bayou, through Lakes Pontchartrain and Borgne, then along the Mississippi coast to Mobile.  Obviously, this was successful because New Orleans flourished, becoming the richest and second largest city in America at one point.

Later, a canal (Carondelet Canal, later New Basin Canal) was constructed that connected Bayou St. John with the rear of the French Quarter at Rampart Street.


Turning basin at Rampart. New Basin Canal, opening 1838.

In the area of the French Quarter, the natural levee was about 15 feet above sea level.  This would give protection during most years, but the fledgling city was flooded out in 1719.  The citizens added to the height of the levee until flooded again.  For two hundred years, new levees were built in response to floods.  Plantation owners protected their water's edge, but this did no good if the landowner upstream did not.  Over the years, a rather safe levee system was developed.

So what adversities did the settlers of New Orleans have to overcome?  There were four major obstacles. 

1.  How to keep flood waters away.  This was done by the levees discussed above, but was not finalized until the great flood of 1927 stimulated Congress to protect the entire lower Mississippi River by an elaborate federally funded system of levees.  Today, the levees along the river are 25 ft above sea level and those around the lake are 17 ft.

2.  How to keep dry behind the levees.  Even with the levees, water would fall from the sky and seep through the soil from below.  For decades, New Orleans was a very wet place to live.  It was not unusual for the city to be under two or three feet of water, with locals having to wade or pirogue about to conduct business.  Many of the older homes were built up, having the first living floor 5-10 ft above the ground.  If they were closed around the base, they had windows of various types to allow the humidity to escape.

Several canals were built or augmented (Dublin Avenue, Bayou St. John, and London Avenue) to collect water.  Each of these had a steam driven paddle wheel that endeavored to push the city's water into the adjacent swamps and marshes.  During the last quarter of the 1800s, several attempts were made to acquire funding to build a sewer system to remove the water, but each failed due to lack of funding.

During the very late 1890s and in response to new outbreaks of yellow fever, a group of ladies waged a public information campaign to pass taxes to develop a better drainage system.  They were successful and in 1900, the Sewerage & Water Board had a system in place that allowed them to daily drain the canals, thus allowing New Orleans to dry out with an immediate decrease in the number of mosquitoes and an increase in property values!

When the going gets tough, a hero usually arises.  In 1899, the New Orleans Sewerage & Water Board hired a young engineer named A. Baldwin Wood.  He tackled the issue of lifting large quantities of water over the levee so that it could be flushed into the surrounding lakes.  In 1912, he developed his 12 ft screw pump (a large propeller specially designed to lift water) that is still in use today. 


The system is very elaborate today.  There are 90 mi of covered canals and 82 mi of open canals.  The total pumping capacity (1993) is 24 billion gallons per day.

  1. How to build on the soils. The soil layers of the delta (thus New Orleans) are varied.  Remember that the sea came and went, the river has frequently changed its course, swamps and marshes have grown and then been displaced, etc.  Each of these events left a mark in the soil profile (the layers found in a cross-section of the soil).  

Engineering Geol of NO

The best way to see these layers is to visit a construction site.  When the wetlands around the Louisiana Nature Center were built, the holes that were dug revealed alternating layers of sand and silt, evidence of the changing surface of the land over time.

Soil profile E NO

Sand, of course, is the most stable and compacted soil type and is thus preferable for building.  When the sand is at the surface, as on a ridge (like the Metairie or Bayou Sauvage ridges), a foundation can be laid on the surface with no support.  The sand supports the foundation and does not subside.

Silty and clayey soils are much less sturdy.  When building a house on these soils, pilings must be driven into the ground to support the foundation so that the forgiving soils do not settle unevenly and tilt or crack the foundation.

Pilings in soil 2

  The pilings either hit a sand layer and were directly supported by it or they were driven into clay layers and the friction around the pile held it up (the so called friction pile).  

Pilings in soil

If these slip, it is disastrous for the slab at the surface.  

Here are photos of a foundation being prepared in which piling were driven into the ground.  The first image is immediately after the pile driving with pilings still sticking out of the ground at various heights.  The second is after they were cut to the same height before the concrete was poured, then the third is the actual slab after being poured (the tops of the pilings are in the concrete and support the slab weight).

Pilings lake corner Harrion & West End December 2017

Pilings Bonnabel at Desmotheness Kenner Lake corner RAThomas 12-21-17


Slab over pilings Bonnabel & Desmothenes Metairie RAThomas 1-9-18

Corner Bonnabel Blvd & Demosthenes St., Metairie

Some of the older buildings in the city, such as the city's first “sky scraper,” the three story [now four] (Pierre) Pedesclaux-(Yves) LeMonnier House at 640 Royal (corner of St. Peter) were constructed on floating cypress log mats that distributed the weight over a larger area.  

Yves Le Monnier House St

Pedesclaux-LeMonnier House, 640 Royal St.

It is always rumored that the Custom House on Canal Street is constructed on bales of cotton; this is untrue and it is also on cypress mats.

The worst soils of all are the peats that exist where marshes existed before being drained.  Peat is truly organic soil and when it is drained, it oxidizes rapidly, returning to its component minerals and occupying much, much less space.  In some places in the region (such as northern Williams Blvd. in Kenner, Academy Drive and environs in Metairie, and Michoud Blvd. in eastern New Orleans) have experienced as much as 3-4 ft of subsidence, leaving enough space under some slabs so that an adult can bend over and walk underneath.  

Subsided house 2


Subsided house 4

Both of the above houses are on Michoud Boulevard (the lower is 4826 Michoud Blvd) in eastern New Orleans.  The photos were taken in the 1989 & 1991, respectively, and have now been repaired.


When soil subsides, people have to buy new soil and spread it around.  For most folks, this is not a big deal.  I do about three cubic yards every five years or so (and much of that is for gardens).  Some people, however, have a bigger job.

Dirt Piles Camphor 02

This subsided property is on Camphor in Metairie.

Metairie 6612 Page 03

Metairie corner Kawanee & Greenacres 03 1

Picture 017

Metairie Kawanee & Page 03


Subsidence fill Lafreniere St 8-3-03

The above 5 photos are from west Metairie

During the 1970s, several houses were destroyed when they exploded due to subsidence.  All were concrete slab houses and used natural gas.  As the soil shifted and subsided, it cracked the gas pipes that entered the slab.  This allowed gas to accumulate in air pockets under the slab until a spark caused the trapped gas to explode.  In order to avoid this accident today, all new construction uses flexible pipe at joints under the slab.

  1. How to design buildings for the local environment.  Early settlers built simple Creole cottages on the ground.  When subjected to floods, they raised them so that flood waters would not get into their living quarters. 

creolecottage off ground
Raised cottage with porch, hipped roof, side walkways, and louvered shudders.


Cottages at ground level, gabled roofs, abat-vents to shunt rainwater into the

 street gutter.  625-627 Dumaine


Cottage that is slightly elevated with foundation vents, gabled roof, dormers,

 abat-vent roof.  719 Toulouse St.  


creolecottage two stories
Cantilevered gallery, louvered shudders on second floor, long plank

Shudders, on first, louvered shudders on second floor.

creolecottage w air vents
Raised cottage with louvered shudders and foundation vents – 823 Royal St.  

Closed shudders prevent stoop sitting by random people.


An anomaly in the highly controlled French Quarter, a small California 

Cottage at 818 Royal.


Eventually, these raised Creole cottages were the dominant house type, with the living quarters about ten feet above the ground.  This allowed for flood protection, storage underneath, and, during hot weather, the doors could be opened and the wind blowing under the house would help cool it.  Many, such as Madame John's Legacy, part of the State Museum at 632 Dumaine, built in 1788, have large covered porches to provide useful space during frequent rains.  

madame johns legacy

The last wooden house in the French Quarter – no more allowed after the 1788 & 1794 

fires that destroyed the area.  This is part of the Louisiana State Museum, 

Madam John’s Legacy.  632 Dumaine.


Virtually all construction used French doors.  They were managed for the temperature:  they could be left open for a breeze; when the night air cooled down, they could be closed to keep the cool air in and the morning hot air out for a while; they could be left closed on the east side in the morning to prevent the rising sun to heat the room (during the winter the opposite could be done - opening them early to allow the rising sun to warm a cool room); the same options were available for the western side in the evenings.  

The great fires of 1788 and 1794 burned out all the Creole cottages and they were replaced with the town houses that are so characteristic of the French Quarter today.  Some say this style of architecture is from the Mediterranean.  Others maintain it is directly from Haiti, which was closely economically associate with New Orleans at that time.

Town House at 624 Dumaine.  The decorative

Wrought iron work on galleries cover the banquette

(sidewalk) below.


Their galleries were decorative, but they also protected pedestrians from rain and windows from direct sunlight.  There were originally almost never galleries or awnings on windows that face east (so as to allow the early morning sun in), but they were almost always present on the west (to shade from the afternoon sun which is much hotter).  

East facing windows

East facing wall in the French quarter.

This is the Bosque House at 617-19 Chartres.

The arched opening is the carriage way opening,

and the architectural name for such a design

is loggia.



Try to imagine the challenges of living in the newly developed New Orleans in the 1700s.  There were no levees, so there was frequent flooding.  The heat and humidity were inescapable, so what could folks do?  It was not new to the times – it was a human challenge all over the world, but what to do in this very hot, very humid, sultry environment?  Add that there was no waste disposal or drainage system.  And not to mention venomous snakes, alligators, and groups of unhappy Native Americans.  Worse yet were the arriving ships full of sailors who may have been at sea for months who wanted to “have a good time,” with little regard for the rule of law.

All that said, New Orleans provided incredible opportunities and people searching for a better life continually arrived.

Even in 1718, there were smart designers and builders who surveyed the conditions and began introducing adaptive ideas.  As a baseline, buildings were one or two stories high, and lots of the design took advantage of those conditions.

If viewed from above, almost all buildings were the same height – regulated by code (look at the French Quarter proper today).  

View of the French Quarter showing that there are no tall

buildings.  This is by design and the drawings below of a typical 

French Quarter home shows how the winds work.


So how does this help living in the sultry New Orleans environment?  As you will see below, houses evolved to include courtyards, kitchens in out-buildings, and other adaptations that ultimately provided more tolerable living conditions.  Winds from the river and lake blow over the roofs and a physics phenomenon occurs:  the Bernoulli Principle.  Not advocating that the early city’s designers were scholars of physics, but what they ultimately designed took advantage of basic scientific principles, especially Bernoulli’s Principle.  It is known that when air moves over a surface it will lessen the air pressure below that surface.  

First example:  The reason an airplane flies is that its wings are aerofoils – that is they are thicker at the front and less at the rear, and the bottom of the wing is flat.  As the wing encountered air molecules at the leading edge, those that go over the top have to go faster than those that travel along the bottom as they meet at the rear of the wing – thus the air is moving faster across the top of the wing, making the air pressure on top less than on the bottom, so the wing is “lifted” by air pressure differential.  

Second example:  when I was a teen we would go to the local store to buy cokes, then we’d sit outside and talk and smoke cigarettes.  Invariably, someone who finished their soft drink would absentmindedly blow smoke into the bottle.  The smoke would stay there until the person blew air across the bottle opening thus making the air pressure lower above the bottle than inside the bottle, thereby invoking the Bernoulli Principle so the smoky air in the bottle came out like a chimney.


With the design you see in the renderings below, note that the wind blowing over the Quarter off the river and lake literally suck the air out of the courtyards via Bernoulli's Principle.  This sucked-out air has to be replaced, so a breeze is created down the carriageway and through the rooms of the house when air is pulled off the street and from under the galleries to replace the air removed from the courtyards.  The stucco covered brick walls allow water to be absorbed from the ground, often causing moist stucco walls.  As the air moves past the walls, the water in the walls evapo-cools the air.  The same happens as the air passes over the plants and fountains.  If the windows are open in the main house, a breeze passes through the living quarters.  All of this works very effectively.  The next time you are in the French Quarter on a hot day, simply step into a carriage or walk way opening and feel the cool breeze.

Of course, today most homes and businesses are air conditioned, but there are homes that are still cooled – at least during certain seasons – by this traditional technique.

The typical French Quarter town house was perfectly designed for its location in New Orleans.  The following architectural renderings are based on the dwelling at 725 Ursulines, once owned by environmentally oriented architect Steve Bingler, and they illustrate how the breezes blow and how the Bernoulli Effect operates. 

courtyard side view

courtyard top view

First, the rooms were usually arranged in a linear fashion so that air could move from the street directly to the courtyard.  Of course, they had French doors, with and without louvered panels, so they could control air movement (plus security).  They had the kitchen in an outbuilding across the courtyard from the main house to remove the cooking heat from the living quarters.  For those who owned slaves, this is where they were housed (slave quarters); many used this arrangement for their adolescent sons (it was then called a garçonniere) so the boys could come and go without disturbing the family. 


Main house (right), courtyard (center), and garçonniere (left).  The last is where the

kitchen was located to keep the heat out of the living quarters and reduce the danger of 

fire.  707 Toulouse.


 The alley leading from the street to the courtyard served many purposes.  If it was narrow, it was a walkway; if wide, it was called a carriageway since the family carriage would enter here for security and so that the ladies could step down without being in the normal muddy street. 

carriage way

Carriageway in the French Quarter.  921 Chartres.


Walkway in the French Quarter.

921 Chartres.


Soft matrix between bricks, 839 Chartres.


Stucco covering of bricks, 814 Royal Street.


 The walls were usually covered with stucco for increased stability (the bricks and matrix between them were inferior by today’s standards, and they absorbed water which aided in evapo-cooling but made them less stable.

WDSU courtyard fountain

The Pharmacy Museum courtyard, 514 Chartres, taken in 1981.

and there were plants and a fountain in the courtyard which enhance evapo-cooling. 

Remember the earlier discussion regarding placement of sleeping room to take advantage of summer evening breezes.  Many other types of New Orleans houses duplicate many of the concepts discussed above.  Look around as you drive around town.  You will see many good examples, such as shotgun houses and doubles (which are basically one building with two side-by-side shotguns).

California Cottage with camelback, Esplanade Avenue.


camelback Aunt Thelma Walntu St

Camelback – with a “basement” and living quarters

 usually two stories in the rear.  252 Walnut Street.



Classic “shotgun” house.  All the rooms are in a line

 for air circulation.  Got its name because one can shoot 

a shotgun through the entire house.  Elysian Fields,

 but ain’t dere no mo!



Wrong!  There are a few families who still have homes just over the levee in the batture (remember that word?) of the Mississippi River.  They are easy to visit.  Just go down River Road to the Jefferson Parish line (at the railroad tracks were the street into New Orleans become Leake Avenue), park and walk up on the levee.  You will see a number of homes that are grandfathered in from current rules that supposedly prevent people from building in these areas.  For the average citizen, the legal ramifications are murky at best – see the last image below of a house that appears “new” when photographed on May 14, 2019.

It is important to know that over the history of New Orleans, the batture has always been inhabited - often as shanty towns, or so called “Hoovervilles” a la John Steinbeck’s The Grapes of Wrath.


Description: 15_batture_camp_custom-b837ceb70a25ee949a43a38dc8b95e1abef558d1-s900-c85.jpg


Those who live in the batture love its serene qualities and the removal from the hustle and bustle of city life.  Some lived there because they simply had not money or family, but others adopted and acclimated to the batture way of life.  They were, however, living on a time bomb.  Sooner or later, the river will flood them out.

Batture homes NO 02 1

Batture Homes NO 02 4

Batture Homes NO 02 6

Description: p1030652.jpg
January 25, 2016, by Urban Bicycle Journeys

Description: p10306541.jpgJanuary 25, 2016, by Urban Bicycle Journeys

May 14, 2019, a seemingly newly constructed house, by RAThomas.


An interesting question is, who owns the batture?  It is a big grey area, and the people who live there are basically squatters.  The local governments refuse to get involved, and are letting a sleeping dog lie.  All of these buildings are in Jefferson Parish.

In the latest version of master planning (early in the Marc Morial administration in 1993), adopted city policy is to preserve the forested batture areas as wildlife sanctuaries.  There are frequent attempts to use them otherwise - always in association with a private development plan.



Soil and Location

What type of soil is on the property?  It should be sand or sandy-loam.  This consolidates well and can support the weight of your home.  If too organic, you will have constant subsidence problems.

What is the flood history?  Obviously, one doesn’t want to settle in a flood prone area.  If there has been flooding in the past, has there been recent flood protection that will do the job?

Is any neighboring property higher than that which you are considering?  If any are, rain will run into your yard and keep it flooded or too moist.

Is there any undeveloped (but developable) property within a mile or so?  If so, code requirements may well dictate that the developments will be higher than your property, so you may have to deal with more water in the future than now.

Is the sidewalk level?  If so, is it lower than the neighbor's; if so, is it new?  Is it lower than the grass?  This tells you something about on-going subsidence.

Does the last section of the sidewalk slant up to the porch?  Driveway to garage?  If it does, this clearly means that they have subsided and the slant was retrofitted.

Is the street level well below the living level of the house?  Water runs downhill!

Is the street cracked?  More evidence of subsidence in the neighborhood.

Do the street drains appear workable?  If not, you will surely flood due to back up of rainwater.

Is there subsidence around the edge of the slab?  Is soil (even if grassed over) steeply stacked around the slab?  A bad sign.  The soil will probably continue to subside.

If the house has natural gas, is there proof that the connection under the slab is not rigid?  If not, slight subsidence may crack the rigid connection and leak natural gas into the subsided pocket under your house.  A spark can cause a devastating explosion.

If a marble is dropped in the center of a room, does it stop or roll to a corner?  This means that the floor is not level, probably due to subsidence that one can=t see.

Are there any cracks visible (or repaired) on inside and/or outside walls?  If so, these probably resulted from subsidence.

Is there hurricane strapping?  If not, then a hurricane may cause the house to collapse.

For new construction, are metal studs used instead of wood?  Termites eat wood.  Why tempt them?


What is the orientation of the house?  Is it designed to absorb morning sun and is it protected from the west?  Is it landscaped with deciduous trees on the south and west?  A house with the living spaces” facing west or south may well get so hot during the summer that either the air conditioner must run constantly (very expensive) or the room will be so hot that nobody wants to relax there.  A workable solution is to plant deciduous (leaves fall off in winter) trees and bushes along the west and south sides of the building.  This way, the leaves block the heat in summer (when one wishes to keep cool) and lets it through in winter (when one wishes to keep warm).  Obviously, this can be planted after a house is purchased.

How is the roof ventilated?  There are many ways that this can happen.  The fans ventilate heat, but the energy cost for the fan motor seems to be about the same as the energy savings from ventilating.  Ridge vents are passive and cost nothing after instillation.

Is the house well insulated?  Insulation in the attic and the outside walls are extremely important in the hot south.

Are there lots of windows on the north side?  Are they double pane glass?  In winter, the cold winds blow from the north, especially the northwest.  If there are windows on the north, they should be double pane glass.

Are there lovely vaulted ceilings inside?  If so, realize that they will literally consume huge amounts of energy supply for cooling and heating.  Ten to twelve foot ceilings are equally attractive in the main rooms, and much more energy friendly.

Does the house have way more square footage than you really need now, or even later?  If so, then you will (1) pay heating/cooling of the square footage for years and (2) you will pay taxes on excess square footage.  Both of these will escalate over the years.

Non-environmental considerations:

  • Examine the roof thoroughly.  Are there weak spots?  Any areas where animals have access to the attic?  Signs of leakage where there is (or should be) flashing?
  • Visit the house at night and on weekends.  Your neighbor may have a large potato chip truck parked at the edge of the property, or the neighbor may work on motorcycles until late at night!  Is the neighborhood full of barking dogs?
  • If gardening is important to you, is there a space in which to grow vegetables that gets the right sunlight?
  • Are there too many trees growing in neighbor’s yards that will drop limbs in your yard, or that have overhanging limbs that will become a problem for you?
  • Plan for the future.  Is there enough parking for when your kids have cars?
  • What is the traffic like on your street?  If a corner lot, on each street.
  • Are there elements on the property that will bug you?  (e.g., street signs, fire plug, sewerage lift pump, telephone poles, etc.).
  • Is there enough driveway space (off street parking) for the family?  Now and in the foreseeable future?



Do you think both of the families that built these houses had the same information available?  

Lifted house Jean Lafitte Town LA 7-10-15

Photo taken in Town of Jean Lafitte, July 10, 2015.


Since Hurricane Katrina, there have been many houses lifted to make them more resistant to flooding.  Check them out around the city and see if you can recognize those that have been lifted.


Lifted house Jean Lafitte Town LA 7-10-15 2

Town of Jean Lafitte, July 10, 2015.