Sediment Flux and Fate in the Mississippi River Diversion at West Bay: Observation Study

Land-building sediment diversions, such as the Mississippi River Diversion at West Bay, are being used as important building blocks in the conservation and restoration of Mississippi Delta wetlands. We have studied sediment deposition and retention in the West Bay diversion outfall area through analyses of sediment cores, bathymetry, and hydrodynamics. Cores and x-ray samples were collected at twenty stations in March 2004, August 2004, November 2005, and April 2006. Cores were sub-sampled in 2 cm increments and analyzed for grain size distributions and ⁷Be activities which can be linked to recent sediment deposition. Bathymetric surveys were conducted in November 2005 and April 2006 and will be used to compare significant elevation changes to bay bottom contours. Data analysis for the study focuses on the ⁷Be results in comparison with hydrodynamic forcing functions such as river and diversion flows and major storm activity.