The Atchafalaya Basin: A Landscape Rewritten by Water and Man

 Reading the Maps of a Changing River Swamp

Recently I attended a meeting at Bayou Pigeon where several people there ask me did I know of any old maps ie, 1800's that would show how the streams / bayous have been affected by inevitable Hydrology changes that occur year to year in the Basin. 

Comparing mid-twentieth-century historical maps with modern USGS topographic maps provides a particularly revealing perspective. At both regional and local scales, these comparisons document changes in open-water boundaries, the development of new land masses, the proliferation of access canals, and the shifting courses of established waterways.

For commercial fishermen and generations of modern-day swampers, these changes are more than cartographic observations. They represent practical realities. Familiar bayous become obstructed, traditional passages become shallow or disappear, and new routes must be discovered and navigated.

The maps therefore tell a story extending beyond geography. They document the continuing transformation of a living ecosystem and the adaptability of the people whose livelihoods, traditions, and cultural identity remain tied to its waterways.

Maps are tools for teaching history to the public. Maps (Cartography) involve two main aspects of accuracy, Topographic and Spatial Accuracy. Topographic accuracy concerns the depiction of features; Spatial accuracy refers to the location of features relative to each other.

Most historical maps (pre-1900) are generalized, they are a simplified view, i.e., map scales do not allow every bend of a river or a road to be presented

Following the Louisiana Purchase, American cartographers Maxfield Ludlow, 1812, Mathew Carey (1814), a James Cathcart 1815 and William Darby (1816), were commissioned by the U.S. Government to explore (map) Louisiana gulf coast area. 

 They were the first to produce printed maps of the state which included the Atchafalaya Basin. Thus, they identified and named some major waterways and bayous in the area!

Maxwell Ludlow Map 1809 -1 812

Excerpt from Ludlow Map

Note this except shows Ludlow did establish some names as early as 1809.  Grand River, Pigeon Bayou, Bayou Gooler (Goula) and Bayou Indigo Lake Verret, Cow Island, and he identified a Drovers Road, which corroborated the history of Cattle drives across the Atchafalaya basin.

Darby map of 1816

There were no maps that truthfully portrayed the spatial accuracy of the water courses of the Atchafalaya Basin until the first USGS maps in 1935 era.

The Public Lands survey system developed in the Basin 1832 - 1836, ie. Township and Range and sections. – 1836. Which established lines of latitude and longitude coordinates. Latitude = of degrees of distance north and south from the equator, which is 0 degrees, lines of longitude coordinates are measured according to 90 degrees east and west of the prime meridian. 

Use of lines of latitude and longitude coordinates would provide spatial accuracy. The problem is there were no cartographers preparing maps of the Atchafalaya Basin back then.

The Union Army in 1863 is a prime example of a simplified view. The Federal Government commissioned General Nathaniel Banks to develop a military map of the Atchafalaya Basin to facilitate the Union Army to protect the Western Front of Louisiana from attack by Confederate's from Texas after the fall Vicksburg, Mississippi in 1863.

That map did a good job of drafting existing roads in and around the basin and to a lesser extent the streams / bayous in Atchafalaya Basin. However it did not but provide any spatial accuracy. 

1863 Civil War Map by Maj. General Nathaiel P. Banks

Excerpt of  of 1863 Map

Excerpt covers the Bayou Pigeon, Pierre Part, Belle River Vector of the Basin

Excerpt of 1863 map

The February 8, 1863, map associated with Banks and Abbot therefore provides valuable evidence identifiable overland routes already existed from Plaquemine, following the Grand River

corridor toward Bayou Pigeon, from Bayou Goula to the 'Parks" area, (Jack Miller's). The Pierre Part & Belle River areas are intersting because they show the likely routes of the Cajuns used for the original routes to migrate to those areas.

The appearance on a military map prepared during the Civil War strongly suggests that this road

system did not suddenly emerge as a wartime development. Rather military cartographers were likely recording routes that had evolved gradually over many years from earlier settlement trails, plantation

and farm roads, towpaths, and cordelle roads used by local residents for transportation and commerce. 

By 1863, these routes were sufficiently established and recognizable to be mapped for military use. In this sense, the Banks and Abbot map preserves an important snapshot of a transportation network whose origins likely predated the Civil War by decades

The map also showed more named bayou names than any previous maps up to 1863. Note Cross Bayou, and Bayou Go to Hell (Aka Bayou Godel)

Swamp Lands of Jeanerette L&S Co Map 1892

Recognizing the importance of strategic and tactical planning necessary to manage the large tracts of land and standing board feet of lumber. H.B. Hewes general manager of the Lands of the R. H. Downman Cypress commissioned their engineers to draw up a map of the lands owned R.H, Downman using the Public Land Survey System (PLSS) survey method.

Route of Atchafalaya River through the Natural Atchafalaya Basin

It was the first map of the Atchafalaya Basin to do that. That is, by Township – Ranges, Sections, and Lots, Per the original 1832 – 1836 government surveys

This map was used to develop strategic and tactical plans to extract the cypress timber on The Downman-owned properties and keep others from stealing the timber.

Fred Kyle, owner of Kyle Lumber once told the author that back in the day that some unscrupulous lumber companies would just buy the property that fronted major waterways because they controlled the access and steal all the timber behind the frontage property. He stated they would come to regret that with oil and gas mineral rights after 1930.

That map did provide some spatial accuracy relative to Latitude and Longitude. But not nearly enough to determine where water courses started and stopped. 

But it was improvement over all previous maps.

Veins of the Atchafalaya

The term "veins" is a common metaphor for a river system's tributaries and streams, which form a branching, treelike network. This network, also known as a drainage basin or watershed, collects surface water and groundwater and channels which carries the accumulated water toward a lake or the ocean. 

Tributaries (the "Veins") are small channels flow downhill, following the path of least resistance. This convergence pattern creates the "vein-like" appearance when viewed from above.

A 2013 search in Google Earth could find no imagery of a swamp anywhere in the world with as many manmade access canals as the Atchafalaya floodway. 

To understand how all the Natural Waterways, Logging Access Canals, Oil & Gas Access Canals and Pipeline Canals affect the hydrology and landscape of the Atchafalaya river basin requires a chronological sequence of when they were created.

The Cypress Logging industry from 1890 to 1935 left hundreds of miles of logging access canals.

In the 1950’s a major increase in petroleum-related exploration and drilling in the  Atchafalaya basin. This increased the need for oil field access canals and pipelines to move product to refineries and petrochemical.

During that time period, oil and gas energy was critical to the economy of the United States. 

Thus, from 1950’s to 1990’s, over 600 miles of large access canals and pipeline canals were dredged through deep swamp areas, across bayous, and across the Atchafalaya River. 

A substantial portion of these access canals were for inland offshore drilling rigs used in the basin oil and gas exploration. By the end of the 1990’s the rate of new construction was greatly reduced.

1935 USGS 15 min. Quad Map

This is first map that would could define spatial accuracy., ie you could get starting points and end points of Streams / Bayous. With modern day GPS devices, you can get within +/- 3 ft.

USGS Map 1955 Chicot Lake

USGS Map 1955 Chicot Lake

Streams & Bayous in the Bayou Pigeon Area 

The Turkey Bayou Area

Turkey Bayou Original Route

What is called the Cutoff by Commercial Fisherman  Swampers

The 'Cut Off' was so named by the local commercial fisherman from Bayou Pigeon because it offered a shorter route to lower Big Bayou Pigeon and Grand Lake, ie., it bypassed the big meander of Big Bayou Pigeon shortening the route by several miles.

Aerial  mosaic Upper Grand Lake 1940

Aerial Mosaic Upper Grand Lake from USCOE  1940

The image demonstrates that the filling in of Grand Lake was like the deltaic plain of a river basin. It was inevitable, The Atchafalaya River was essentially exactly as a alluvial valley.

Following the catastrophic Great Mississippi Flood of 1927, the U.S. Army Corps of Engineers shifted strategies from simple levee-building to creating dedicated floodways. 

Summary: The Cartographic Shift in the Atchafalaya  BAsin

Historical and modern maps provide a definitive visual record of the Atchafalaya Basin’s transformation from a dynamic, wild river swamp into a heavily engineered floodway.

 Because hydrology dictates the landscape, cartography has documented the radical changes forced onto this region by massive sedimentation, natural river avulsion.

The Spillways Protection Levees that permanently locked the basin into a narrow, centralized corridor.

Maps pinpoint this engineered floodway, turning a living wetland ecosystem into a relief valve for structural flood safety

Because the controlled floodway forces massive amounts of muddy Mississippi water through a confined space, the Atchafalaya became an immense sediment trap. 

Historical Macro maps feature giant open-water bodies like Grand Lake and Six Mile Lake. Modern maps show these have been entirely filled in by silt, converting open water into willow-dominated land masses.

Micro-maps (USGS) reveal the internal fragmentation of the basin.

Oil & Gas Access Canals: Exploration maps from the mid-to-late 20th century show thousands of grid-like canals dredged for timber harvesting and oil and gas extraction.

Spoil Banks: The earth dug up from these canals was piled alongside them, forming "spoil banks." 

These artificial ridges act like mini-dams, blocking the natural east-to-west sheet flow of water, trapping sediment, and changing the routes of existing streams/bayous.

A highly dynamic river swamp adjusting to unnatural hydrology, ie, Intricate grids of oil, gas, and logging canals accompanied by long parallel spoil banks.

Wild fast currents during the annual flood pulse, shifting rafts of logs, fast growth of scrub shrub & black willows contribute to changes in the routes of streams and bayous.  

Comparing mid-20th-century maps to USGS maps of today reveal the stark changes in the route of bayous that the commercial fisherman and modern day swampers have to adjust to year after year. 

The Atchafalaya Basin is not a static landscape. It is a constantly evolving river system, shaped by the competing influences of nature, engineering, and human enterprise. Its maps are the historical record of that transformation.