Mid-Barataria Sediment Diversions

Gulf of Mexico Project

 

 

 

 

Diversion of the Mississippi River to stem the loss of coastal wetlands

Scientists with the National Oceanic and Atmospheric Administration (NOAA) are using the Integrated Ecosystem Assessment approach to provide the State of Louisiana and other organizations ecosystem science important to effectively manage the loss of coastal wetlands, sustain valuable marine resources, and the needs of coastal communities. NOAA’s Integrated Ecosystem Assessment (IEA) approach integrates all components of an ecosystem, including human well-being, into the decision-making process so that managers can balance trade-offs and determine what actions are likely to achieve their desired goals.

Marsh in the GUlf of Mexico
Marsh in the Gulf of Mexico

 

The State of Louisiana is proposing to construct diversions of the Mississippi River to stem the catastrophic loss of coastal wetlands in Louisiana. There are many agencies and organizations involved in this decision-making process. The Louisiana Coastal Protection and Restoration Authority (CPRA) has applied for a permit to develop a diversion in the Barataria Basin near Myrtle Grove, Louisiana, called the Mid-Barataria Sediment Diversion (MBSD). The U.S. Army Corp of Engineers is the permitting agency. The proposed sediment diversion would be a permanent structure built within the levee structure/system. A robust adaptive management plan to manage diversion operations is also planned to optimize intended outcomes and minimize deleterious impacts on the ecosystem.

map of Barataria basin
Map of Mid-Barataria Sediment Diversion Site

Integrated Ecosystem Assessment of the Barataria Basin provides objective science for the diversion project

This proposed diversion provided an excellent opportunity for NOAA to pilot implementation of an Integrated Ecosystem Assessment. The IEA approach supports an adaptive management framework for the proposed Mississippi River sediment diversions and integrates important ecosystem information into the decision making throughout operations of the project.

The first step of this Integrated Ecosystem Assessment was identifying the goal of the project and defining the system in which this project will occur. The goal of the sediment diversion project is to maximize sediment transport from the Mississippi River to the Barataria Basin to build, sustain, and maintain land.

A conceptual model of the Mid-Barataria Basin was developed to identify all the important components of the system. The model was constructed by a team of diverse NOAA social, ecological, and other scientists and reviewed by local experts, partners (federal and state agencies), and non-government organizations (NGOs).

Proposed conceptual ecological model of the Mid-Barataria sediment diversions.
Proposed conceptual ecological model of the Mid-Barataria sediment diversions.

 

As part of the next step of this IEA, in February 2018, NOAA scientists held a workshop with stakeholders from federal and state agencies, academia, NGOs, and others involved in the diversions project to identify a preliminary suite of ecological indicators to assess the status, natural variability, and long-term trends of the Barataria Basin prior to the diversion construction and operation. The Barataria Basin conceptual model was used to ensure that major components of the ecosystem have a relevant indicator. These indicators will help to predict impacts of the diversion and measure if the restoration goals are being met. 

Part of identifying these indicators included assessing if the data currently being collected within the Barataria Basin is sufficient to inform managers and the adaptive management process. Data for these indicators were gathered from a multitude of scientific resources.

Identifying and assessing these indicators establishes a stronger understanding of societies relationship to the ecosystem. This will facilitate an assessment of both the state of the ecosystem and human communities along the coast and help determine if the diversions are being optimally planned and operated.

Impacts of the diversion to humans and their well-being

NOAA's Integrated Ecosystem Assessment approach recognizes the importance of understanding the connections between humans and ecosystems, and the significant role that the environment plays in human well-being and incorporates that into the decision-making process. So NOAA scientists are using the IEA approach to understand the impacts of the proposed Mid-Barataria sediment diversion to humans and their well-being and incorporate that information into the decision-making process.

For ecologists and coastal managers the Barataria Basin is a wetland but for its residents, this place evokes strong emotional, historic and economic associations. Agencies working on this project are aware of the importance of discussing societal goals for this project and the Coastal Protection and Restoration Authority (CPRA) planning document emphasizes the fact that this project has been created with the local communities in mind. So there have been efforts to gain an understanding of the public opinion.

NOAA scientists are identifying the best method to include a broad and inclusive public opinion on this project. A literature review was done to identify different methods of engaging local communities in management decisions. One method identified to best represent the various communities in the Basin was to use ethnographic research to develop relations and trust with key representants and then design a long-term program that allows these communities to come up with some of their own solutions to this problem.

In addition to ethnographic research, NOAA scientists are also is in the process of developing consensus around a results chain to include the impact to humans and thoughts of all things important to local communities into the decision-making process.

The results chain is as follows below:

  1. If we deliver sediment, freshwater, and nutrients then we reduce land loss 
  2. If we reduce land loss then we sustain the Deepwater Horizon injured wetlands
  3. If we sustain wetlands then we reduce long-term impacts from sea-level rise and storms
  4. If we reduce long-term impacts from sea-level rise and storms then we protect historic properties and traditional living cultures and their ties and relationships to the natural environment
  5. If we protect historic properties and traditional living cultures then we sustain the unique cultural heritage of Coastal Louisiana

Informing the adaptive management process

With the goal identified, the system defined, and preliminary indicators selected the next step in the Integrated Ecosystem Assessment of the Barataria Basin is to assess the ecosystem and develop an ecosystem status report. NOAA scientists are using the identified indicators to develop an ecosystem status report of the Barataria Basin prior to development. This information will help to inform the adaptive management process.

Ultimately NOAA's IEA approach will provide information on important components of the ecosystem, including human-well being, to managers for decision-making processes (regulatory commenting and consultation) associated with diversion operations and inform the development of an adaptive management process to monitor post diversion.