• Barrett Ristroph

The Morasses of Louisiana’s Coastal Wetland Restoration, Part 1

This is Part 1 of a two-part blog. The full-length article with references will be published in the LSU Journal of Energy Law and Resources and will be available at https://ristroph.wordpress.com/articles/.

Around the world, sea level is rising. Coastlines are eroding. Particularly in the State of Louisiana, land valued by industry and communities is disappearing. Once far-fetched, ideas of reclaiming and recreating land don’t seem so strange anymore. In 2017, when I first read about the State of Louisiana’s plans to reconstruct islands off the coast, and to divert Mississippi River sediment toward land-building, I was enthused. After all, an area greater than the size of Delaware was lost between 1932 and 2016.[1] Coastal wetlands losses throughout Louisiana could range from 42% to 99% by 2100.[2] Shouldn’t we do everything in our power to restore it?

Once I started to work with federal and state agencies in Louisiana on coastal restoration in 2019, the answer to this question became less clear, entangled with who will benefit from the restoration projects and who will not. In this two-part blog, I outline the temporal and uneven nature of benefits and costs, and call for a way to better assess restoration projects before and after moving forward. The first part of the blog considers the causes of land loss and what the State of Louisiana has done (and not done) to address them.

Causes of Land Loss

Louisiana’s coastal land loss story is more nuanced than some. To date, reduction in sediment deposition from the Mississippi River, oil companies, and subsidence—not climate change—are largely responsible for much of the land loss.[3] Not only is there less sediment coming down the river due to dam and reservoir construction and better erosion control. There is also a levee system designed to spare New Orleans and the petro-chemical industry corridor along the river from flooding. The levees have largely eliminated the “overbank” sediment that previously flowed from the river into adjacent wetlands.


Levees and sediment reduction are only part of the problem. The other part concerns the oil and gas companies have been operating in Louisiana with few constraints since 1901. Today, Louisiana is among the top ten oil-producing states and top five in natural gas production.[4] Dredging canals into Louisiana’s wetlands has been a long-standing practice to provide access to drill sites. The resulting saltwater intrusion has slowly destroyed coastal wetlands and hastened coastal erosion. Oil and gas companies have not restored wetland development sites despite legal requirements to do so, and the Louisiana government has long looked the other way.[5] Add to the list of oil and gas damages the 2010 Deepwater Horizon oil spill, which killed vegetation holding wetlands in place.[6] And add to these the major factor of land subsidence resulting from delta compaction[7] as well as oil and gas extraction.[8]

All of this is not to deny the effects of climate change on Louisiana wetlands. Sea level rise is slowly inundating wetlands and will likely become a greater factor as time passes. The increasing severity and frequency of storms like Hurricane Katrina also has ties to climate change. The major hurricanes that struck Louisiana in 2005 (Katrina on Aug. 29 and Rita on Sep. 24) and 2008 (Gustav on Sep. 1 and Ike on Sep. 13) destroyed an estimated 328 square miles of coastal wetlands in Louisiana.[9]

State Action

Following Hurricane Katrina in 2005, the Louisiana Legislature created the Coastal Restoration and Protection Authority (CPRA) and tasked it with creating and regularly updating a master coastal plan. The plan might have been doomed to unfunded purgatory until funding came in the form of the 2010 Deepwater Horizon oil spill settlement funds. A Deepwater Horizon restoration plan created by Gulf states and federal agencies spurred various land creation projects, mainly in the form of dredging material from one site and placing it onto an artificial island at another site. Such projects builds up land quickly, but the new land can erode or subside away in just a few decades.

A key example is Queen Bess Island, west of the mouth of the Mississippi River. In 2019, the state and federal government spent more than $450,000 per acre to create the island.[10] The projected lifespan of the island is only a couple of decades, after which the island may be under water due to sea level rise. While Queen Bess Island is now part of a State-managed refuge, the lands for similar projects are typically privately owned, and restoration comes with no easement or conditions to ensure that landowners will maintain the habitat.

A potentially more sustainable method of building land is to divert sediment from the Mississippi River, which is a self-replenishing source of material. This method does not build substantial land early, but allows for land to grow over time. The 2017 coastal restoration plan called for seven sediment diversions along the Mississippi River to send sediment, fresh water, and nutrients from the River into designated areas to build wetlands there.

The largest proposed diversion, known as the Mid-Barataria Sediment Diversion (MBSD) system is planned for Plaquemines Parish along the west bank of the Mississippi River, just upriver from the town of Ironton (consisting mainly of the descendants of enslaved people). The goal is to have up to 75,000 cubic feet of water per second at various times of the year diverted to the sediment building area. At that maximum flow, the diversion is expected to move 40,000 tons of sand, silt and clay per day into the sediment building area. The aim is to build around 30,000 acres of land after 50 years.[11] The project is projected to cost $1.4 billion in funds from the Deepwater Horizon oil spill settlement.[12] The engineering and construction companies involved in this and other projects stand to gain a great deal. Likewise, the City of New Orleans and the petro-chemical industrial complex operating along the Mississippi River upriver from New Orleans may be spared from inundation for a little longer.

Others will fare less well. As the salinity decreases in the waters around the diversion, the area will no longer be suitable habitat for species like dolphin, brown shrimp, and oysters. Dolphins will likely die (the local population is resistant to moving). The diversion will affect those who depend on shrimp and oyster harvest commercial and subsistence use. The predominately low income, minority communities (environmental justice communities) just downriver of the diversion will also likely be affected by increased flooding and storm surge. It is still not clear how these impacts will be mitigated. In short, the oil and gas industry will continue to drill unmitigated along the cost (a proposed $2.5 billion, crude oil export terminal is actually planned to go alongside the diversion), Louisiana’s other major industry (seafood)[13] and the people along the coast stand to lose.

[1] B.R. Couvillion, Holly Beck, Donald Schoolmaster, and Michelle Fischer, Land area change in coastal Louisiana 1932 to 2016: U.S. Geological Survey Scientific Investigations Map 3381 (2017). [2] Patty Glick, Jonathan Clough, Amy Polaczyk, Brady Couvillion, and Brad Nunley, Potential Effects of Sea-Level Rise on Coastal Wetlands in Southeastern Louisiana, 63 J Coastal Research 211, 226 (2013). [3] Robert H. Baumann & R. Eugene Turner, Direct impacts of outer continental shelf activities on wetland loss in the central Gulf of Mexico, 15 Env. Geo. & Water Sci.189 (1990); Cathleen E. Jones et al, Anthropogenic and geologic influences on subsidence in the vicinity of New Orleans, Louisiana (2016); Robert R. Twilley, et al, Co-evolution of wetland landscapes, flooding, and human settlement in the Mississippi River Delta Plain, 11 Sustainability Sci. 711 (2016). [4] U.S. Energy Information Administration, Louisiana State Profile, https://www.eia.gov/state/analysis.php?sid=LA#:~:text=for%20air%20conditioning.-,Petroleum,total%20oil%20reserves%20and%20production (last visited Aug. 19, 2020). [5] See Oliver A. Houck, The Reckoning: Oil and Gas Development in the Louisiana Coastal Zone, 28 Tulane Environmental Law Journal 187 (2015). [6] Amina Rangoonwala, Cathleen E. Jones, and Elijah W. Ramsey III, Wetland shoreline recession in the Mississippi River Delta from petroleum oiling and cyclonic storms 43 Geophysical Research Letters 11,652 (2016). [7] Krista L. Jankowski, Torbjörn E. Törnqvist & Anjali M. Fernandes, Vulnerability of Louisiana’s coastal wetlands to present-day rates of relative sea-level rise 8 Nature communications 14792 (2017). [8] Brendan Yuill, Dawn Lavoie, and Denise J. Reed, Understanding Subsidence Processes in Coastal Louisiana, 54 J Coastal Research 23, 32. (2009). [9] J.A. Barras, Land Area Change and Overview of Major Hurricane Impacts in Coastal Louisiana, 2004-08: US Department of the Interior, US Geological Survey Scientific Investigations Map 3080 (2009). [10] Louisiana Trustee Implementation Group (LA TIG), Phase 2 Restoration Plan/Environmental Assessment #1.1: Queen Bess Island Restoration (2019), available at, https://www.gulfspillrestoration.noaa.gov/sites/default/files/2019-03%20LA%20Final%20QB%20RP%20EA%201.1%20031419_508%20Compliant.pdf 2-6. [11] Louisiana Trustee Implementation Group, Strategic Restoration Plan and Environmental Assessment #3: Restoration of Wetlands, Coastal, and Nearshore Habitats in the Barataria Basin, Louisiana (2018) [12] Mark Schleifstein, Mid-Barataria Sediment Diversion could create, save 47 square miles of land over 50 years, The Advocate (Jan. 4, 2020) https://www.nola.com/news/environment/article_fba3837c-28d8-11ea-844c-bf1ddc3a10e1.html. [13] See Louisiana Seafood, Economy of Seafood, https://www.louisianaseafood.com/industry (“One out of every 70 jobs in Louisiana is related to the seafood industry, which as a whole has an economic impact of over $2.4 billion annually for Louisiana.”)

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