Calcasieu-Sabine Basin wetlands collapsing, experts say

The Calcasieu-Sabine Basin in Southwest Louisiana is experiencing a collapse of its coastal wetlands that experts now describe as “Barataria bad,” a reference to the catastrophic land loss seen in other parts of the state. According to reporting, the region—once considered one of the most stable stretches of the Louisiana coast—has destabilized due to rising sea levels and uncontrollable inundation, threatening roughly 312,500 acres of fresh, intermediate, brackish, and saline marshes.

This shift represents a critical failure of managed coastal units. For decades, the Calcasieu-Sabine Basin was the outlier in a state losing land at an alarming rate. It was a place where cows still grazed on stable ground while other parishes vanished into the Gulf. Now, that stability has evaporated, leaving the region vulnerable to saltwater intrusion and permanent inundation.

A cycle of stability and collapse

The current crisis is not a new phenomenon, but rather the third major destabilization event in the region’s modern history. From the 1930s through the 1970s, the primary drivers of land loss were shipping channels, which acted as conduits for saltwater to penetrate deep into the freshwater marshes. To combat this, the state constructed levees and water-control structures in the late 1970s.

Those early interventions worked for a time, but the environment proved fragile. The region destabilized a second time following the devastation of Hurricane Rita. While the land recovered partially after that storm, it has now entered a third, more complex phase of decline.

Leigh Ann Sharp, a coastal wetlands expert with the Louisiana Coastal Protection and Restoration Authority (CPRA) who has monitored the coast for over 20 years, noted that the current issue differs from the shipping channel intrusions of the past. The problem now is that these are impounded wetlands relying on gravity drainage. When salt marshes remain inundated for extended periods, they lose their structural integrity and collapse.

“When we started monitoring, the Calcasieu-Sabine Basin was stable. There were cows walking around out there; we thought it was the most stable part of the coast. But when sea levels rose and inundation became uncontrollable, it destabilized. It is now ‘Barataria bad’ in the Calcasieu-Sabine Basin — and this is happening inside managed units that we ought to be able to control.”

The $260 million effort to reverse the tide

The stakes extend beyond the loss of grass and soil. These marshes serve as the first line of defense against storm surges for inland communities and provide the essential breeding grounds for commercial fisheries. If the marshes vanish, the economic engine of the Southwest Louisiana coast—built on fishing and shipping—loses its natural buffer.

To stop the bleed, the state is implementing the Calcasieu-Sabine Large-Scale Marsh and Hydrologic Restoration Project. The total scope of the project is $260 million, supported in part by a $122 million grant from the RESTORE Act. The strategy is twofold: improving how water leaves the basin and physically rebuilding the land.

The first phase focuses on the Cameron Creole Watershed, where seven lake-rim gravity drainage structures are being constructed. These structures are designed to reduce the “persistent inundation” Sharp warned about, allowing water to exit the marsh more efficiently and reducing the stress on the vegetation.

Simultaneously, the project is utilizing a method of strategic nourishment. Material excavated from historic bayous is being placed back into the marsh to create new land and nourish existing footprints. By dredging these natural channels, the CPRA aims to restore the exchange of water between the marsh and Calcasieu Lake, mimicking the natural hydrologic flow that existed before human intervention.

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