Restoring Hydrology and Vegetation in Des Allemands Swamp: Actions Taken for Wetland Recovery
The Des Allemands Swamp, located west of Lac des Allemands in St. James Parish and south of the town of South Vacherie, has undergone a significant transformation thanks to the EPA-sponsored Hydrologic Restoration and Vegetative Planting project (BA-34-2). This project, the first swamp restoration project funded under the Coastal Wetlands Planning, Protection and Restoration Act (CWPPRA), was designed to improve the swamp's hydrology, vegetation, and overall ecological health.
The project is strategically positioned to benefit from the natural resources surrounding it. It is bordered on the south by Bayou Chevreuil and on the east by Louisiana Highway 20. The Des Allemands Swamp project is a collaborative effort involving St. James Parish, the Barataria-Terebonne National Estuary Program, and the Louisiana Coastal Protection and Restoration Authority.
The area, which had been cut off from the natural flow of water due to human activities over time, was in a state of impoundment. This condition was caused by the addition of levees, undersized culverts, and spoil banks. To relieve this impoundment, efforts were made, including installing culverts, but the area couldn't fully drain and connect to Bayou Chevreuil.
To reconnect the swamp to Bayou Chevreuil, construction contractors removed heavy vegetation and excavated engineered gaps. Initially, the plan was to provide freshwater from the Mississippi River into the swamp, but a siphon was found to be not feasible. Instead, CPRA engineers designed a plan to clear and excavate historical gaps in the existing banks that bordered Bayou Chevreuil.
Excess soil was spread as a thin layer in the immediate vicinity to stabilize the soil. A total of 300 water tupelo and 900 bald cypress trees were planted to jump-start the restoration process. The construction of the project took approximately 5 months and cost just over $500,000.
The benefits of such hydrological restoration projects are far-reaching. They aim to restore natural water flow patterns to improve wetland hydrology, rebuild and stabilize wetland vegetation, enhance habitat for fish, wildlife, and plants, increase sediment deposition and nutrient cycling, mitigate coastal land loss, and contribute to climate resilience by buffering storm surges and sequestering carbon.
The success of the Des Allemands Swamp project is evident in its outcomes. The project enhanced 2,395 acres of swamp habitat that would have otherwise continued to degrade. According to Gary Shaffer, Professor of Biological Sciences at Southeastern Louisiana University, statistically significant regeneration was measured within the first year.
Hydrological restoration projects like the Des Allemands Swamp project can be constructed efficiently and cost-effectively, resulting in higher cost-benefit ratios compared to traditional marsh restoration projects. These projects not only improve the health of the wetlands but also support local fisheries and communities by preserving the unique ecosystems they rely on.
For more detailed information about project BA-34-2, including measured benefits and monitoring results, it would be necessary to consult official EPA reports or project documentation directly from the EPA or Louisiana Coastal Protection and Restoration Authority. For those interested in learning more about CWPPRA projects, I recommend reading the CWPPRA BA-34-2 project fact sheets and exploring other EPA-sponsored CWPPRA projects.
The Des Allemands Swamp project, designed to improve the swamp's hydrology, vegetation, and ecological health, is situated near the natural resources of Bayou Chevreuil and Louisiana Highway 20. Originally intended to provide freshwater from the Mississippi River, the project instead cleared and excavated historical gaps in the swamp's border with Bayou Chevreuil. After planting water tupelo and bald cypress trees, the project successfully enhanced 2,395 acres of swamp habitat, contributing to climate resilience, fisheries, and local communities. To learn more about the project's benefits and monitoring results, consult official EPA reports or project documentation. Moreover, hydrological restoration projects like this one can offer higher cost-benefit ratios compared to traditional marsh restoration projects, making them a valuable investment for environmental science, health-and-wellness, and fitness-and-exercise, as well as climate-change mitigation and overall environmental wellbeing.
