Mississippi River Priority Site: Atchafalaya River

 

Byron Jorjorian (Great egret in the Atchafalaya National Wildlife Refuge, Louisiana)

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Working with Agriculture

Learn more about the Conservancy's work with the agricultural community to improve water quality in Mississippi tributary streams.

Restoring Connections

Explore the Mississippi River, its floodplain and the Conservancy's efforts in restoring connections for people and nature.

Ecological Threats

Conservation Strategies

Other Priority Sites

Bayou Bartholomew

The Big Woods

Boone River

Cat Island - Tunica Hills

Cypress Island

Donaldson Point - Reelfoot Lake

Emiquon

Hatchie River

Horseshoe Lake

Lower Black River

Lower Cedar River

Lower St. Croix River

Lower Yazoo Basin

Mackinaw River

Military Ridge Prairie Heritage Area

Mingo Basin

Obion Creek and Bayou de Chien

Pecatonica River

Pine City Natural Area

Root River

Sand Ridge Lands

Spunky Bottoms

St. Francis National Forest

Tensas River Basin

Weaver Dunes - Zumbro River

How We Protect Watersheds

Explore a cool interactive feature to see how the Conservancy protects freshwater resources worldwide.

The Atchafalaya River is a distributary of the Mississippi and Red rivers; that is, it receives water from the two larger streams rather than emptying into them. From its confluence with the Mississippi, the Atchafalaya runs southward through Louisiana approximately 140 miles to the Gulf of Mexico.

Agricultural and forested lands occupy the northern end of the Atchafalaya's basin. On the southern end are marshlands and the river's forming delta at the Gulf. Between these two points lies the largest expanse of swamp wilderness on the North American continent, an area teeming with a globally significant diversity of life.

Without the U.S. Army Corps of Engineers' Old River Control Structure northwest of Baton Rouge, the Mississippi would likely change course and the Atchafalaya would become its main channel. As it is, the Corps, in response to the Great Flood of 1927 on the Mississippi, built a floodway through the heart of the Atchafalaya basin. Enclosed east and west by levees averaging about 15 miles apart, the floodway provides a diversionary route for high Mississippi waters to reach the Gulf, thereby reducing potential flood damages in the downstream urban areas of Baton Rouge and New Orleans.

Within the basin, the Louisiana Department of Wildlife and Fisheries manages 43,618 acres as one unit that includes the U.S. Fish and Wildlife Service's 15,220-acre Atchafalaya National Wildlife Refuge, the state's 11,780-acre Sherburne Wildlife Management Area and 16,618 acres owned by the U.S. Army Corps of Engineers.

The Corps has acquired 47,323 acres within the basin and has obtained land preservation and flood passage agreements with owners covering an additional 108,440 acres.

The Atchafalaya basin supports more than 200 species of birds, serving as key nesting territory for some and as a critical staging area for migrants crossing the Gulf of Mexico each spring and fall. It is also home to endangered species such as the Louisiana black bear, peregrine falcon and Bachman's warbler. Economically important harvests of crawfish and fish are produced from the basin, which shelters more than 85 fish species.

Strategies and Progress

Land use and river changes in the Atchafalaya and Mississippi river systems have resulted in a loss of the cypress and fisheries resources, a severe hypoxic (deficient in amount of oxygen) zone in the shallow waters of the Gulf of Mexico and profound rates of wetland loss along Louisiana's coast. And while The Nature Conservancy has been involved in coastal restoration for many years, hurricanes Katrina and Rita emphasized the increasing vulnerability of Louisiana's coast and economy to coastal wetland loss and compromised floodplains. We are now faced with an increased urgency to advance restoration of these systems. Our activities with partners align along three major strategies:

  • working with governments to secure and influence prioritization of public funds for ecosystem restoration;
  • promoting sound science and conservation planning to inform development and implementation of appropriate restoration strategies in the Atchafalaya and along the coast; and
  • reaching out to stakeholders including landowners, businesses and local governments to promote ecological understanding and conservation of the Atchafalaya basin and larger coast and create a vision for restoration success. 

Photo credits (top to bottom, left to right): Great egret in the Atchafalaya National Wildlife Refuge, Louisiana © Byron Jorjorian; © TNC