Getting Down to Basics: The Environmental Impact Statement Process for the Mid-Barataria Sediment Diversion


As CPRA advances the Mid-Barataria Sediment Diversion and other priority projects toward construction, Restore the Mississippi River Delta staff experts will aim to give you updates on key steps of the process.

The Mid-Barataria Sediment Diversion aims to be “the first controlled sediment diversion reconnecting the Mississippi river with its delta,” Louisiana’s Coastal Protection and Restoration Authority (CPRA) indicated in a recent press release, and, recently, there have been some important developments toward that end. In March, CPRA announced that they were soliciting firms to support the engineering and design of the project. This follows two announcements in January indicating that the White House had placed the diversion on its Federal Permitting Dashboard—a “government-wide effort to streamline the federal permitting and review process while also increasing transparency”—and that CPRA had selected a third-party firm, GEC, Inc., to conduct the Environmental Impact Statement (EIS) for the Mid-Barataria Sediment Diversion in coordination with the U.S. Army Corps of Engineers (USACE).

Yesterday, CPRA issued a press release indicating that, as part of the EIS, it had identified a baseline operations alternative of 450,000 cubic-feet-per-second (cfs) to use as a starting point to model how the Mid-Barataria sediment diversion could be operated in the future.

By selecting this baseline alternative, CPRA will be able to conduct modeling to better understand how operating the diversion in this way will impact land-building and other factors. Getting more data and a better understanding of these effects will allow CPRA to select a true operations strategy that will improve the success of the sediment diversion. Additionally, this will provide CPRA with baseline data that can be used to better inform the public and other stakeholders, including the numerous federal agencies involved in the EIS process, about how the Mid-Barataria sediment diversion can be operated to better understand its effectiveness and effects. What’s most important is that this announcement is a starting point, not a definite conclusion, on the road to getting this critical restoration project constructed and operating in order to rebuild and sustain our vanishing wetlands.   

The EIS process is both complex and important. So, we wanted to answer some key questions, discuss why yesterday’s announcement is truly a starting point on operations, and provide an overview of what to expect in the months ahead.

What is an EIS and why is it necessary?

An EIS – or Environmental Impact Statement – is required as part of the National Environmnetal Policy Act (NEPA) process. NEPA was signed into law in 1970 and “requires federal agencies to assess the environmental effects of their proposed action prior to making decisions,” ranging from permit applications to the construction of large-scale infrastructure. The process aims to allow involved agencies to understand the potential environmental, economic and social impacts of a proposed action and make decisions on that action or alternative actions presented throughout the process. While NEPA was originally enacted to understand a project’s negative implications on the environment, it also has to be utilized for projects aimed at restoring the environment – in this case, Louisiana’s rapidly disappearing coast.  

For the Mid-Barataria Sediment Diversion, CPRA has had to file several federal permits in order to proceed with the diversion. The first is a 404 Permit under the Clean Water Act that regulates material being placed into water or wetlands. CPRA must also file a 408 permit as part of the Rivers and Harbors Act of 1899 to get permission to alter federal public works projects, in this case the Mississippi River levee. In order to issue these permits, USACE has to conduct an EIS to determine the impact of the diversion on the environment.

Who is involved in the EIS process?

A lot of agencies. First, the United States Army Corps of Engineers is the “lead agency” – the federal agency charged with executing the requirements of the project under NEPA. CPRA is involved as the “cooperating agency” – the state agency with local expertise and jurisdiction. Other federal agencies that have input include the Environmental Protect Agency, U.S. Fish and Wildlife Service, and the National Ocean and Atmospheric Administration. The Council for Environmental Quality (CEQ) is the administrating agency of NEPA.

The public is a key part of the EIS process as detailed below.

How can the public give input on the EIS and throughout this process?

In the EIS process, meetings called “scoping meetings” are held to present available information of a proposed project or action to the public and others involved who are able to provide public input on the project. These scoping meetings are the earliest point for public comment in this process; however, they are not the only opportunities. The public can also give input and formal comment on the notice to prepare an EIS, which happens after scoping, as well as the draft EIS and final EIS and the proposed action. The proposed action is the course the agency decides to take after developing and considering an Environmental Impact Statement.

This process is just getting started, and there will be ample opportunities for the public and other stakeholders to give input in the months and years ahead. 

Will the operations alternative announced be the strategy used to operate the actual diversion?

In short, it’s still too early to say. We don’t believe so. The 450,000 cfs is a starting point that will likely get refined and adjusted in the months ahead as CPRA gathers more information and the EIS process advances. Through the EIS process, various operation refinements will be developed and tested through science and modeling. We didn’t have the funding to do the type of analysis that will happen over the next few years, but we did bring together a group of experts to discuss how operations will happen in the real world. They don’t believe that this baseline alternative would actually be implemented in any given year. More on their recommendations below.

What have scientists said about the operations of sediment diversions?  

Last year, a group of scientists developed a report and series of recommendations on how a sediment diversion could be operated if the goal were to maximize land-building, while considering other effects. The Sediment Diversion Operations Expert Working Group, convened by Environmental Defense Fund and Restore the Mississippi River Delta, consisted of 12 leading scientists with decades of experience working in coastal Louisiana. They examined a variety of topics related to diversion operation for the report: “Building Land in Coastal Louisiana: Expert Recommendations for Operating a Successful Sediment Diversion that Balances Ecosystem and Community Needs.”

In short, the group provided recommendations, such as “sediment diversions should be operated on a pulse that mimics the natural flood cycle of the Mississippi River, which includes taking full advantage of winter flood peaks, when the greatest concentration of sediment is available in the river to sustain the coastal wetlands.” While no substitute for the EIS process currently being executed by GEC, Inc. and CPRA, many of the recommendations will also be considered as part of the EIS for the Mid-Barataria Sediment Diversion and could inform, along with additional modeling and data and public and stakeholder input, how the Mid-Barataria Sediment Diversion will actually be operated. You can learn more at:

Still have questions? Where can I learn more?

We hear you! This stuff is wonky. The Environmental Protection Agency has a great overview of the National Environmental Policy Act Review and Environmental Impact Statement processes on their website. You can also get in touch with us for specific questions, and we’ll try our best to answer.   

View more on the Mid-Barataria Sediment Diversion.