Mississippi River Sediment Delivery System – Bayou Dupont (BA-39)

wordpress fact sheet banner BA-39-01

Marshes in the project area have degraded to open water with only scattered clumps of low-lying vegetation remaining. Marsh degradation has resulted from a combination of lack of natural fresh water and sediment input, subsidence and the dredging of oil and gas canals.

The proposed project included dredging sediment from the Mississippi River for marsh creation and pumping it via pipeline into an area of open water and broken marsh west of the Plaquemines Parish flood protection levee. The material was spread over the project area and ontained primarily with existing land features. Newly-constructed low containment dikes were necessary only along a limited portion of the project area. Native intertidal marsh vegetation was planted post construction.

The proximity of the project to the Mississippi River presented a prime opportunity to employ a pipeline delivery system that utilized the sediment resources from the river to restore and create wetlands. Unlike most marsh creation projects that involve borrowing fill material from adjacent shallow water areas within the landscape, this project utilized renewable river sediment, thus minimizing disruption of the adjacent water and marsh platform.

The Bayou Dupont project represents the first example of pipeline transport of sediment from the river to build marsh as a CWPPRA project. Results from this project helped demonstrate the value and efficacy of greater use of pipeline-conveyed river sediments for coastal restoration.

map

The project is located adjacent to Bayou Dupont and southeast of Cheniere Traverse Bayou in the vicinity of Ironton in Plaquemines Parish and Lafitte in Jefferson Parish, Louisiana. The general area lies west of LA Hwy 23 and just north of the Myrtle Grove Marina within the Barataria Basin.

Phase 1 was approved in January 2003. The Louisiana Department of Natural Resources (LDNR) Coastal Engineering Division performed the engineering and design services. Design was completed in November 2007; Phase 2 was approved in February 2008, and construction activities began in April of 2009. Approximately 25,935 linear feet of containment dike was used to create approximately 484 acres of sustainable marsh in Marsh Creation Areas 1 and 2. Increment 2 (funded through ARRA) added approximately 84 acres of marsh within 6,241 linear feet of containment dikes. The contractor demobilized completely by May 10, 2010. Final inspection was held on May 25, 2010.

This project is on Priority Project List 12.

The Federal Sponsor is EPA

The Local Sponsor is CPRA

One thought on “Mississippi River Sediment Delivery System – Bayou Dupont (BA-39)

  1. A few corrections: The containment dikes were not “low”, and while the location allowed the agencies to use existing spoil banks and levees to minimize the need for constructing additional containment dikes, the marsh was, and still is, almost entirely impounded by the various levees, spoil banks, and containment levees. As the primary wetland ecologist involved in the project since its inception (though not the project manager), I repeatedly recommended to the project managers and engineers that containment dikes needed to be thoroughly gapped, or better yet, completely removed. They ignored this recommendation, and did so with gusto. Therefore, to this day, this expensive constructed wetland remains only partially functional. I continue to use it as an example of the arrogance and dismissiveness of engineers and project managers in what is supposed to be ecological restoration, frequently, and in many venues.

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