Monday, April 22, 2013

Impassable Cypress Swamps

As so many tilling and paving projects are currently underway in New Orleans, we thought it timely to quote from city paving engineer Bryson Vallas' 1926  lecture to the Realtor Salesmen's Division on "Paving and Allied Projects."

"Expansion for most cities, has meant merely the cleaning away of the forrest that surrounded it, and finding that Nature had already provided the land on which to locate the farm, the home or the factory. When our ancestors left the confines of the little settlement nestled behind the two foot levee in the bend of the Mississippi River they found their task of expansion a bit more difficult, especially when this expansion was lakeward, for not only was the cypress and the gum forrest to be cleared away but the land upon which this future expansion must grow, had to be made.

"Old maps of New Orleans made in 1798 show the Old City, or the Cieux [sic] Carre, as we pridefully term it, surrounded by impossable [sic] cypress swamps and by laying out on these old maps such thoroughfares as Canal, Claiborne, Broad and Carrollton, as we know and use them today, we find these these cross through the very heart of this swamp of 128 years ago.


"The unimproved streets of New Orleans consist usually of a fairly hard top crust about one foot thick under which is found a very saturated plastic clay soil. In paving, this top crust is removed and after installing sub-surface drainage the tendency of the sub-soil is to dry out. There is therefore the problem of placing a pavement on a none too stable sub-grade which in later years and after completion of the pavement, will dry out and subside.

"We therefore see in all parts of the City pavement curbs sunken almost out of sight, manholes protruding above the pavement surface and catch basins that were once at the lowest point of the street now occupying a place at the highest point. Treatment of the sub-grade would no doubt result in correction of the unstable sub-grade at the time of paving but only as the soil is drained years in advance will any near correction of the subsequent sub-grade settlement be accomplished."

Bryson Vallas. "Paving and Allied Projects." Realtor Salesmen's Division Lecture. Typescript. 1926. Martin Shepard Office Records, Southeastern Architectural Archive, Special Collections Division, Tulane University Libraries.

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