Gulf of Mexico
Mid-Barataria Sediment Diversion project / CPRA

USA - Coastal Protection Is Too Important Not To Experiment With

To realize a future in which we thrive with water in a place as precarious as New Orleans, we need to tinker–to experiment with strong inference and learn from success and failure. A very controversial wetland construction project underway in Louisiana presents a prime opportunity to demonstrate that this approach—intentional investments in clinical trials for planetary health—can catalyze progress. Should we tinker with it?

A Go-Big or Go-Home Project As Host for These Experiments

In late 2022, the Army Corps of Engineers granted permits for the Louisiana Coastal Protection and Restoration Authority (CPRA) Mid-Barataria Sediment Diversion project on the west bank of the Mississippi River. This $2.5 billion coastal restoration effort will transform a tract of real estate, currently protected by the levee system, into a thriving freshwater wetland ecosystem, reportedly becoming one of the largest environmental infrastructure projects in the history of the United States. In the wake of Hurricanes Rita and Katrina, CPRA was formed to have the authority to set priorities and focus development and implementation to protect Louisiana's coast.

According to the CPRA, Louisiana’s coast has lost more than 2,000 square miles of land in less than a century. This is a chunk of sand and wetland plants the size of EIGHT Phoenix metro areas and FOUR Los Angeles metro areas. Gone into the ocean. And the pace is picking up: Sea level rise caused by climate change is exacerbating the problem, and 300 square miles of marshland was lost in just four years (2004-2008) in the wake of Hurricanes Katrina, Rita, Gustav, and Ike. Another Phoenix gone into the depths of the Gulf dead zone. The CPRA estimates an additional 2,250 square miles could be lost over the next 50 years. If your jaw isn’t being scooped up off the floor at this point, I am preaching to the wrong choir. The math is just jaw-dropping to me.

The Mid-Barataria Sediment Diversion Project (MBSDP) will barrel through a US Army Corps levee and reconnect the Mississippi River to the Barataria Basin to offset some of the past and future loss. What that really means: The coastal wetlands created by the project will protect communities from the inevitable storms that are increasing in frequency and severity. It could, however, mean much more. MBSDP is a cutting-edge, expensive and complex project. Go big or go home. That’s the way we do it down South. So why not get everything we can out of it?

The Potential: Multiple Benefit Revenue Stacking

With only incremental additional investments, scientists could integrate new and existing instrumentation in projects outlined by the new Coastal Master Plan(including the Mid-Barataria Sediment Diversion) to enable pre- and post-monitoring evaluation and state-of-the-art statistical analysis. With a commitment to science from the outset, this project offers a chance to not only improve the protection from hurricane damage delivered by coastal forests, but to also learn how to optimize infrastructure projects and management for two enormously important issues that are interrelated to coastal protection in the lower Mississippi River Basin: carbon sequestration and nutrient reduction.

Wetlands are well-known to be carbon sinks and the state of Louisiana has ambitious decarbonization goals in addition to rebuilding coastal ecosystems for hurricane protection. The potential of the Mid-Barataria Sediment Diversion project in terms of immediately applicable cause-and-effect data related to carbon storage is as enormous as the spatial scope of the project.

The CPRA has proposed other coastal protection interventions — and they have the potential to be either carbon-positive or carbon-negative. Louisiana has a climate action plan which was spearheaded by Chip Kline, the executive director of CPRA and a climate advisor to Louisiana’s governor. Could coastal restoration be a key tool for decarbonizing the state as a side benefit to protecting coastal communities from storms? Science could be the link between these efforts, ensuring they are optimally aligned.

Most importantly, science can stack all these benefits and revenue sources in ways that illustrate how coastal restoration pays back project costs in terms of credits. Could the future of coastal protection stimulate and sustain markets and transactions that improve the ecosystems, communities and businesses of the Gulf? My wager: yes to all of the above.

The Key: Careful Measurement and Intentional Experimentation

We know wetlands and sediment sequester carbon. We know they also retain nutrients. But how do you optimize a project the scale of MBSDP to deliver stacked benefits given the uncertainty of biogeochemistry with wet-dry cycles and oxidation of organic matter? And as importantly: How do we prioritize these side benefits in the context of the Coastal Master Plan?

We will need careful measurement and experimental control. To be explicit: What's needed is a comprehensive, systematic and coordinated before-after measurement approach of all the cost-benefits of those projects. What would be even better: Make these projects a little more intentionally experimental as they are being executed.

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