Compromise on Coastal Restoration: A New Approach for Rebuilding Louisiana's Wetlands

Coastal restoration scientist and professor Ehab Meselhe has proposed a new concept for rebuilding Louisiana's wetlands, which combines pulsing diversion with sand or mud "engines" to create new marshland. This approach, based on previous scientific experiments, aims to mimic the natural processes that originally created the delta region at the mouth of the Mississippi River. Meselhe's idea draws from earlier bodies of knowledge and has yet to be published, meaning it hasn't undergone academic scrutiny.

Key Takeaways:

• Meselhe's concept uses pulsing diversion, which periodically turns off the flow of water to build new marshland along Louisiana's coast, rather than keeping the flow constant.
• The concept involves transporting dredged sand by the mouth of the floodgate that controls flow from the Mississippi River, which would help build land in coastal Jefferson, Lafourche, and Plaquemines parishes.
• The proposal aims to reduce the river's flow from the original plans, resulting in less land being built but far less dilution in the salinity of the bay's water.
• Opponents of the original diversion have complained about its potential impact on the estuary, its sealife, and the livelihoods it supports, including oyster farmers whose beds would perish.
• Scientists and experts, including Sam Bentley and Alisha Renfro, see problems with relying only on a small-scale diversion for the Barataria Basin, saying it will still pour considerable freshwater into the bay and push salt water further away from the shore.

Statistics:

• 75,000 cubic feet per second of water flow is planned for the original Mid-Barataria Sediment Diversion project.
• Meselhe's computer models show that even with much less water moving than the 75,000 cubic feet per second, they still push saltwater further away from the shore.
• The National Wildlife Federation's Alisha Renfro estimates that changing the salinities within the basin can be achieved with "really small" amounts of freshwater input.

Sources:

• Elise Plunk, "Wetlands in the Wax Lake Delta, one of the few places along Louisiana's coast where land is growing instead of being lost," Louisiana Illuminator.
• Ehab Meselhe, quoted in the Louisiana Illuminator.
• Sam Bentley, professor at Louisiana State University, quoted in the article.
• Alisha Renfro, coastal scientist with the National Wildlife Federation, quoted in the article.
• James Karst, communications director for the Coalition to Restore Coastal Louisiana, quoted in the article.
• Mitch Jurisich, chairman of Louisiana's Oyster Task Force, quoted in the article.