EWN Publications

Marsh Habitat with Beneficial Use of Dredged Sediment from a Riverine Environment

Andrew McQueen, Burton Suedel, Justin Wilkens, Christina Saltus, Joseph Gailani, Jeffrey King, and Jeffery Corbino
October 31, 2020

About This Publication

WEDA Journal of Dredging

Using dredged sediment from riverine environments is a critical component of large-scale (projected multi-billion dollar) restoration efforts in coastal Louisiana (USA) to decrease losses sustained from coastal land loss. West Bay (Louisiana) USA is a 12,000-acre sub-delta adjacent to the Mississippi River that typifies risks of coastal land loss (e.g., loss of critical marsh habitat and threatened navigation banklines), with approximately 70% (ca. 8,000 acres) conversion from marsh to open water since the 1950s. To restore habitats at the scale of projects like West Bay, sustainable approaches are needed. Recently, there has been substantial progress in using restoration strategies that align with Engineering with Nature® (EWN®) principles, a U.S. Army Corps of Engineers (USACE) initiative supporting more sustainable practices for delivering economic, environmental and social benefits through collaborative processes. This study documents the progress of restoring marsh habitat in West Bay through an uncontrolled sediment diversion from the Mississippi River and a series of sequenced dredged sediment placement events to inform future projects aimed to strategically place dredged sediment via application of EWN principles. To achieve this objective, this study documents the historical context and successes of the restoration strategies in West Bay from 2002-2019. The creation of a large uncontrolled diversion (20,000 cfs) in 2003 in combination with Sediment Retention Enhancement Devices (SREDs; created in 2009, 2013, 2015) were successful in using sediment-laden water from the Mississippi River to promote marsh creation. In addition to the sediment diverted from the river, over 37 million cubic yards (MCY) of sediment placed from dredging projects from 2002-2019 facilitated the restoration of over 2,400 ac of land in the formerly open waters of West Bay. Documenting progress and lessons learned of large-scale restoration projects like West Bay are crucial to the success of future restoration investments.