What are Sediment Diversions?

Sediment Diversion Reading List

A sediment diversion is a large-scale coastal restoration project including a structure of gates that will be built into the Mississippi River levee system to allow river water, sediment and nutrients to flow into degrading wetlands to help sustain and rebuild land. Sediment diversions mimic the natural processes that once allowed the river to build the land of coastal Louisiana.

What Went Wrong?

Levees and flood control structures were installed along the Mississippi River to protect ports and communities, improve navigation and keep the river from changing course. These levees prevented the river from depositing sediment into its wetlands, contributing to our land loss crisis and making our region vulnerable to flooding.

What’s the Solution?

Reconnect the river to its wetlands. We have the opportunity to reduce further land loss and restore our coast by using a combination of restoration project types included in Louisiana’s Coastal Master Plan. Multiple projects working together are needed to build and sustain land, but sediment diversions are a crucial foundation needed to confront Louisiana’s ongoing land loss crisis.

The Facts about Sediment Diversions

Over the past several months, we have been hearing a lot of claims about the potential effects of one of the largest coastal and ecosystem restoration projects ever to be undertaken in the state of Louisiana and perhaps the nation – the Mid-Barataria Sediment Diversion. This project is a cornerstone of Louisiana’s Coastal Master Plan and will build and maintain 30,000 acres over 50 years by reconnecting the Mississippi River to its wetlands.

There is too much at stake to make judgments based on inaccurate or misleading claims. Let’s set the record straight on a number of fronts:

Learn the Facts:

1. Diversions Build Land. Period.
2. While not a Sediment Diversion, the Caernarvon Freshwater Diversion Builds Land
3. Wetlands Need Sediment to Survive
4. Roots + Sediment = Stronger Soils, More Resilient Marshes
5. There is more to Sediment than Sand
6. Diversions are Field-Tested and Scientifically Solid
7. The Mid Barataria Sediment Diversion is a Coastal Restoration Project, Not MRGO
8. Diversions + Nutrients = Dynamic Estuaries

Sediment Diversions in the News

It’s time to untame the mighty Mississippi River and stop wasting millions of dollars of sediment each year
By David Muth, Ensia.

“Imagine discovering that a U.S. government agency was operating a 90-year-old program designed with the best of intentions, but wasted a precious commodity. Suppose, for example, that to help out wheat farmers during the Great Depression, the Department of Agriculture began to buy wheat, ship it down the Mississippi River, and dump it into the Gulf of Mexico. And suppose you learned it was still going on today, nearly a century later.”

Old accident in Mississippi Delta holds lessons for saving Louisiana’s coast
By Tristan Baurick, The Times-Picayune.

“An oyster farmer by the name of Cubit had no grand designs when, in 1862, he dug a ditch into the east bank of the Mississippi River; he simply wanted a shortcut for his skiff. But his cut in the lower river delta at Pilottown, about 15 miles below Venice, unleashed the land-building power of the muddy Mississippi. It poured through, widening the ditch into a broad canal that allowed enough river sediment through to create more than 75 square miles of coastal wetland in less than a century.” 

Mississippi River’s high water is a missed opportunity to restore the coast
Steve Cochran, The Times-Picayune.

“These events are yet another reminder of why we need sediment diversions constructed and operated as soon as possible, to help disperse and filter river water through coastal wetlands, rather than sending it into the lake or the Gulf of Mexico, and to take advantage of high-river events to restore our coast.” 

Mid-Barataria Sediment Diversion

The Mid-Barataria Sediment Diversion will mimic natural conditions by directing sediment, fresh water and nutrients from the Mississippi River into adjacent degrading wetlands in Barataria Basin to build and sustain tens of thousands of acres. These new and sustained wetlands will provide vital habitat for a wide variety of wildlife species and a buffer from storm surge for communities and industry.

Since diversions reestablish natural deltaic processes and continuously build land over time, they provide long-term benefits that constructed marsh creation projects alone do not. Sediment diversions provide a regular supply of sediment and fresh water to wetlands, sustaining traditional marsh creation projects while also building new land.

Resources for Mid-Barataria Sediment Diversion 

Mid-Breton Sediment Diversion

The Mid-Breton Sediment Diversion is a key project in the 2017 Coastal Master Plan intended to reduce land loss in the Breton Basin. This project will be located on the east bank of the Mississippi River at Wills Point in Plaquemines Parish. The Mid-Breton Sediment Diversion will build new land and sustain existing wetlands by using the power of the Mississippi River itself to move sediment and fresh water from the river into nearby basins, mimicking nature’s historic land-building processes.

A local’s perspective on the Mid-Breton Sediment Diversion.

Albertine Kimble, Plaquemines Parish Resident

Resources for Mid-Breton Sediment Diversion