At first the canals were all about commerce, but drainage has become their modern purpose. By 1919 with the advent of the Wood Screw Pump and an expanding population the pressure to develop new land continued unabated.
According to the 1919 drainage map pictured here the strategy of the city engineers was to allow water to drain from the city near the river leeves and collect in mid city where the two big pumping stations on Broad would pump it over the Metairie ridge. Once on the lake side, the water would be directed into one of the three outfall canals (17th Street which was then called Upper Monticello, Orleans and London) and pumped out into the Lake.
The navigation canals were still in use in 1919 and are also clearly pictured on this map. The New Orleans Navigation Canal is more typically called the New Basin Canal. The Carondelet Canal which extended Bayou St. John is also known as the the original or Old Basin Canal.
The Industrial Canal shown on this map did not go into service until 1923 and although it finally achieved the goal of a waterway connecting the river and the lake (using a lock at the river). It's opening so late as to be almost irrelevant for that purpose. By 1923 steamships could sail directly up river and within a few years the lake was too shallow for the deep drafts of ocean going vessels.
Inner Harbor Navigation Canal (IHNC), the official name of the Industrial Canal has continued to be a highly useful as an extension of the port and component of the Gulf Intercoastal Waterway and later the Mississippi River Gulf Outlet (MRGO). Efforts to make the IHNC New Orleans primary container port have not panned out and in 1993 a new container facility at the Nashville Avenue dock further diminished the need to use the IHNC facility.
Drainage canals and high capacity pumps
| General: |
End of 1899 |
End of 1925 |
End of 1937 |
| Population |
280,000 |
420,000 |
516,000 |
| Population Area (Acres) |
16,000 |
30,000 |
33,000 |
| Approx. Number of Premises |
67,000 |
103,000 |
125,000 |
| Death Rate: |
| from Malaria (per 100,000 pop.) |
70 |
5 |
2.32 |
| Drainage: |
| Miles of Low Level Canals and Drains |
100 |
560 |
940 |
| Combined Drainage Pumping Capacity |
1,200 |
13,000 |
25,478 |
| Number of Drainage Stations |
7 |
8 |
9 |
| Area Drained in Acres |
13,000 |
40,000 |
50,000 |
PreK - 22 pumping stations could pump 45 thousand cubic feet per
second
out of the city (Orleans only). That is equivalent to just under
1 inch per
hour of rain across the entire 100 square miles (65,000 acres) of
drained land in the city. S&WB claims 90 miles of open
drainage canals and 90 miles of enclosed culverts replacing older sections of canal.