From 1700-1800 the battle against the river was locally orchestrated
and largely lost as spring floods inundated the city on a nearly annual basis.
Construction was limited to the highest areas. Levees began to spring up all along the river to protect local
interests including towns and plantations.
The changes up river
increased the flood danger in New Orleans.
"The inundation in New Orleans in 1813 was due to the breaking of the
Macarty Levee, at the site that later became the town of Carrollton. A still more disastrous experience of the same kind
followed on May 6, 1816, through the collapse of the Kenner Levee, only
a short distance farther up the river.
In 1816 the rear of the city was flooded in some places to a depth of five
feet. The suburbs of Montague, LaCourse, St. Mary, and Marigny, and the
whole of the lesser settlements behind them — Gravier, Trémé and
St. John — were under water for 25 days. It was possible to row in a
small boat from the corner of Chartres and Canal streets to Dauphine,
down Dauphine to Bienville, and down Bienville to Burgundy, thence to
St. Louis Street and Rampart, and out to the settlements mentioned.
The city also had reason to fear unusual tides in Lake Borgne and Lake
Pontchartrain. These might be caused by long-continued south-east
winds, or by some sudden, violent storm, which operated to retard the
outflow from the lakes of the water which usually found its way through
the narrow passages leading out into the Gulf of Mexico. When this
occurred, the water level rose, and the swamp behind the city might be
overflowed, or even the rear of the city itself. The latter happened
in 1831, when as a result of a heavy storm, the lake water flowed in as
far as Dauphine Street; and again in 1837. In 1844 and 1846 a similar
cause sent the lake water in as far as Burgundy Street. "1
The massive 48 day flood in 1849 induced
feverish levee building throughout the lower river valley. Although
there was fierce debate, official policy at the time was to control the
river using levees only. Local Engineer George Towers Dunbar, Jr. who nearly drowned while heroically fighting the 1849 flood had argued unsuccessfully for creation of a bypass channel to the lake at what has now become the Bonne Carre spillway, but the city failed to act, presumably confident that the levees were sufficient.
Between 1850 and
1920 the levees
only policy appeared to be working. Flooding was kept out of the
city proper but continued to damage outlying areas. Levees successfully defended the city in 1844,
1850, 1858, 1862, 1865, 1867,1874,
1882, 1891, 1912, 1922. Surrounding
areas including Jefferson Parish and the Bonnet Carre area flooded repeatedly.
During this time the US Army Corps of Engineers gradually assumed a greater
responsibility for the flood control mission.
In 1923 with little fanfare the Gulf Intracoastal Waterway and The
Industrial Canal were both completed. These navigation canals cut across the city providing commerce and making the Port of New Orleans great. They also divide the city and make it vulnerable to threats in ways never envisioned before 1923. The Industrial Canal effectively "created" the lower Ninth Ward as a cutoff parcel of land, separate from the city proper and bounded to the east by the Arabi stockyards and slaughter houses.
The great flood of 1927 prompted a major policy change. After
a massive breach at Greenville, MS caused intense flooding and with
river levels threatening to breach the levees at New Orleans, the levee
south of the city was dynamited to relieve the strain. Congress belatedly enacted
the 1928
Flood Control Act ending the levees only policy and authorizing spillways
and reservoirs to control flooding.
In 1936 the Bonnet Carré spillway was finished. This spillway just
west and upriver of New Orleans is the city's last line of defense against river flooding and
is capable of diverting 10% of the river's flood volume, some 250,000
cubic feet per second across marshland and into Lake Pontchartrain.
The Morganza flood way expanded the role of the Atchafalaya distributary
allowing it to carry 1.5 million cfs, approximately half of the river's
project flood volume. Additional projects called the Old River Control
structure prevent the recapture of the entire volume of the river into
the Atchafalaya Basin.
1. Kendall,
History of New Orleans ,1922