Alterations along the Mississippi River, such as dams and levees, have greatly reduced the amount of freshwater and sediment that reaches the Louisiana coastal area. Several freshwater and sediment diversions have been proposed to combat the associated land loss problem. To aid in this restoration effort a 1-D numerical model was calibrated, validated, and used to predict the response of the river to certain stimuli, such as proposed diversions, channel closures, channel modifications, and relative sea level rise. This study utilized HEC-RAS 4.0, a 1-D mobile-bed numerical model, which was calibrated using a discharge hydrograph at Tarbert Landing and a stage hydrograph at the Gulf of Mexico, to calculate the hydrodynamics of the river. The model showed that RSLR will decrease the capacity of the Lower Mississippi River to carry bed material. The stage at Carrollton Gage is not significantly impacted by large scale diversions

The Mississippi River (MR) has been engineered with the development of the levee system, dams for flood control measures, jetties, revetments and dredging of the navigation channel. These alterations have reduced the replenishment of the sediment to the Louisiana Coastal area. To aid in the restoration planning, 1-D numerical models have been calibrated and validated to predict the river response to various changes such as channel modifications, varied flow conditions and hurricane situations. This study utilized the HEC-RAS 4.1 and the CHARIMA (Dr. Forrest Holly, University of Iowa). The models were calibrated for hydrodynamics and sediment using Tarbert Landing discharges (HEC-RAS), Belle Chasse sand concentrations (CHARIMA), and Gulf of Mexico (GOM) stages. The models showed that a large percentage of the river flow is lost over the East Bank downstream of Bohemia which reduces the sand transport capacity of the river. This reach is subject to flow reversals during hurricanes.