The Lower Mississippi River Water Trail

Atchafalaya Lower

Rivergator: Paddler’s Guide to

Atchafalaya River:

Atchafalaya River & Basin

© 2015 John Ruskey
For the Rivergator: Lower Mississippi River Water Trail
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presented by the Lower Mississippi River Foundation.
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Atchafalaya River Basin Biotas

The Atchafalaya River flows through four distinct biotas on its 150-mile run to the Gulf, all of which make for unique experiences for paddlers.  Biota 1 - The Canal: The first 40 miles feels a little bit like a canal, and it is.  The levees are close in and there is very little floodplain on either side.  Where you do find wooded floodplain around some of the few bends in this stretch is also where you’ll find the best picnic and campsites.   The river here looks and feels like a smaller version of the Mississippi.  Over the levee you will find big agriculture fields stretching to the horizon, as seen elsewhere in the flatlands of the south.  Biota 2 - Bottomland Hardwood Forests: This all changes at mile 27 where the Morganza Floodway enters from the east and with it the wonderful bottomland hardwood forests it encompasses and protects.  This is the beginning of the river of trees.  Below mile 40 (US 190/Krotz Springs) both sides of the river become engulfed in deep woods.  Ten miles further and all agriculture has become a thing of the past and the Atchafalaya lives up to its name as “the River of Trees.”  The levees end and the batture opens up like a blossoming flower, eventually becoming 20 miles wide.  The Atchafalaya River divides into smaller channels flowing through extensive forests, swamps of the Atchafalaya Basin, and some of its small communities.  Biota 3: Cypress-Tupelo Gum Forests: Below Upper Grand River the bottomland hardwood forests fall away with the high ground and become replaced by the largest contiguous stand of cypress-tupelo gum forests in North America.  From Upper Grand River to Flat Lake in the East Basin, and from Butte La Rose to Bayou Teche in the West Basin the cypress-tupelo gum swamps line most of the bayous, lakes and canals that parallel the main channel.  Note: You won’t see any of these magical forests if you don’t leave the main channel and explore the back channels.  If nowhere else, exit the main channel Blue Point Chute or the American Pass to access some of the cypress wonderland.  Alternate routes will be described further on in the RivergatorBiota 4: Coastal Marshes: Below Morgan City high ground falls away completely and is replaced by endless grassy and caney marshes with some willows and other scrubby undergrowth.  The closer you paddle towards the ocean the banks become shorter and shorter, and the the less land you see.  Eventually the river and its passes flow through a tangled mattress of roots, grasses, and other marshy vegetation.  There is no solid land here, only spongy vegetable marsh.   This is where Louisiana is regaining some last coastland.  These marshes, the kingdom of nutria and waterfowl, are in effect land-makers.  They grab sediment out of the river as the water flows in and the soils fall out, congeal, harden, and make land where once was water.

A Lived-In Landscape

Remember, this is a lived-in wilderness.  The Atchafalaya Basin is a place where man and nature coexist in some kind of harmony; where Cajun families live on the waterways and the outdoors is an intimate part of their daily lives; where houses have been built on stilts hanging over the river, or on wooded banks of the bayou, or on houseboats.  Where the communities end the deep woods begin.  You will experience some of this intimacy with nature, this deep sense of place following the Old Channel of the Atchfalaya River through Butte La Rose.  Or when you wander down Upper Grand Lake, or Bayou Sorrel, or Bee Bayou deep into the heart of the East Basin.  Wherever you go, remember that you are a visitor, and to seek permission whenever appropriate.

Atchafalaya Mileage

We’ll begin mileage corresponding to the USACE Atchafalaya River Charts at mile 0, which marks the flowing water downstream of the end of the Lower Old River Channel, the flatwater canal you just paddled through, and through which all commercial traffic must travel after locking throuhg Old River Lock & Dam.

RBD = right bank descending, LBD = left bank descending

As we continue downstream from here, the Rivergator will indicate features on each side of the river as either RBD or LBD.   RBD = right bank descending, LBD = left bank descending, form the perspective of the paddler descending down the Atchafalaya to the Gulf of Mexico.  If there is no designation the described feature covers the whole channel (i.e. a bridge, or cable crossing or etc).

Gas Pipelines

Not only are they a curiosity for the traveller, but the can be helpful in navigation.  To assist paddlers in locating yourselves on the river, the Rivergator will identify pipeline crossings down the Atvchafalaya River.  Where pipelines make their underwater crossings, large signs are normally posted on the riverbank, saying something like  “No Anchoring.  No dredging.  Pipeline Crossing.”  


Upon entering the Atchafalaya proper the Rivergator will now switch to the Simmesport Gage which can be found online at:


Paddlers planning a trip down the Atchafalaya should consult the Simmesport Gage to get the best idea about what’s going on with water levels on the top end of the Atchafalaya.  Reading the Simmesport Gage with the following divisions for low water, medium water and high water will yield a fairly accurate picture of how much sand will be showing at different locations, which campsites and parks are still above water, and which landings are still usable for vehicles.  Remeber what you see on Google Earth might be vastly different than the actual water level and conditions of the sandbars and islands, and other places of importance to paddlers.

Water levels according to the Simmesport Gage

Low Water = 0 to 12 SG 

Medium Water = 12 to 25 SG

High Water = 25 to 35 SG

Bank Full = 30 SG

Flood Stage = 35 SG and above

(SG = Simmesport Gage)


Flood Stage Warning: above 35 SG paddlers are advised to stay off the river.  Limited access.  Most landings and approach roads will be underwater.  Most islands will be gone.  No easy camping.  All sandbars will be covered.  Fast waters with many hazards.  All islands and landings will be surrounded by flooded forests full of snags, strainers, sawyers and all other dangerous conditions associated with floodwater moving through trees.  Docks, wharves, dikes and any other man-made objects will create strong whirlpools, violent boils, and fast eddies.  Towboats will create large waves.  The Rivergator will not describe the river and its islands at any levels above flood stage.