3 Sep 2025

Hydrodynamics in the Morganza Floodway and Atchafalaya Basin, Report 5: Phase 5

Abstract: The Morganza Floodway and Atchafalaya Basin, located in Louisiana west of the Mississippi River, were evaluated using a 2D Adaptive Hydraulics model. Prior to this study, Phase 1 and 2 model studies showed that the Morganza Floodway may not be able to pass the Project Design Flood discharge of 600,000 cubic feet per second due to levee overtopping. Phase 3 and 4 model studies help to further the understanding of how flood waters propagate throughout the floodway as well examined alternatives to increase the discharge capacity of the floodway. Phase 5 furthered the work completed in Phases 3 and 4 by exploring more alternatives to aid the Morganza Floodway in passing the Project Design Flood.

3 Sep 2025

Hydrodynamics in the Morganza Floodway and Atchafalaya Basin, Report 4: Phase 4

Abstract: The Morganza Floodway and Atchafalaya Basin, located in Louisiana, west of the Mississippi River, were evaluated using a two-dimensional Adaptive Hydraulics model. Prior to this study, Phase 1 and 2 model studies showed that the Morganza Floodway may not be able to pass the Project Design Flood discharge of 600,000 cfs due to levee overtopping. A Phase 3 model study helped to further the understanding of the effects of trees and vegetation on the flow capacity of the floodway. In Phase 4 of this study, changes in elevations through means of excavation as well as the cutting of rights-of-way (ROW) were examined to determine their effects on flow conveyance in the floodway.

28 Aug 2025

South Atlantic Coastal Study (SACS) Calibration and Validation of the Coastal Storm Modeling System (CSTORM) for Water Levels and Waves Part 3. Gulf of Mexico Domain

Abstract: The US Army Corps of Engineers, South Atlantic Division, is currently engaged in the South Atlantic Coastal Study. One of the phases of this study is focused on conducting coastal storm modeling for the eastern and central Gulf of Mexico coastline of the United States. This technical report details the development of input for the Coastal Storm Modeling System (CSTORM) suite of models (WAVEWATCH III, ADCIRC, and STWAVE) for this project and presents the efforts made to calibrate model setups and validate results for eight historical tropical storm events impacting the study area.

28 Aug 2025

South Atlantic Coastal Study (SACS) Calibration and Validation of the Coastal Storm Modeling System (CSTORM-MS) for Water Levels and Waves: Part 2. South Atlantic Coast Domain

Abstract: The US Army Corps of Engineers, South Atlantic Division, is currently engaged in the South Atlantic Coastal Study. One of the phases of this study is focused on conducting coastal storm modeling for the southern Atlantic coastline of the United States. This technical report details the development of input for the Coastal Storm Modeling System suite of models (WAVEWATCH III, ADCIRC, and STWAVE) for this project and presents the efforts made to calibrate model setups and validate results for seven historical tropical storm events impacting the study area.

28 Aug 2025

South Atlantic Coastal Study (SACS) Calibration and Validation of the Coastal Storm Modeling System (CSTORM-MS) for Water Levels and Waves: Part 1: Puerto Rico / US Virgin Island Domain

Abstract: The US Army Corps of Engineers, South Atlantic Division, is currently engaged in the South Atlantic Coastal Study. One of the phases of this study is focused on conducting coastal storm modeling for the Puerto Rico and US Virgin Islands. This technical report details the development of input for the Coastal Storm Modeling System suite of models (WAVEWATCH III, ADCIRC, and STWAVE) for this project and presents the efforts made to calibrate model setups and validate results for four historical tropical storm events impacting the study area.

19 Aug 2025

Numerical Modeling of Coastal Processes with Beneficial Use of Dredged Sediment in the Nearshore at Jekyll Island, Georgia

Abstract: This report provides numerical model results to assist the US Army Corps of Engineers–Savannah District (SAS). These results evaluate beneficial use alternatives for the sediment from an advance maintenance widener of the Brunswick Harbor Entrance Channel between stations −14+000 and −28+000. This study applied a coastal wave, hydrodynamic and sediment transport model (Coastal Modeling System), and a shoreline change model (GenCade), focusing on developing and simulating placement alternatives. Subaerial placement model results indicate better shore and beach preservation than at the nearshore nourishment. Placing sediment closer to the “transition zone” between the revetment and natural beach will increase the volume of sand that remains in that area. Some sediment is predicted to return to the channel, but these volumes are small fractions of the placed material. GenCade results indicate that the transition zone rock debris decreases shoreline erosion. Removing it has less impact on that area than any of the subaerial nourishments, but this prediction does not include profile equilibration that may occur after the first 4 months. Overall, model results indicate that subaerial placement will have strong positive response at the eroding beach, and related increases to channel infilling rates are relatively small.

17 Jul 2025

Overview of the Coastal STORM (CSTORM) Model Development for the Swan Island Restoration Study

Abstract: This document summarizes the numerical model development and validation approach used to simulate the winds, waves, and water levels observed at Swan Island during two prominent historical storm events in the region: Hurricane Sandy and Hurricane Isabel. Using the Coastal STORM (CSTORM) Modeling System, which couples the Advanced Circulation (ADCIRC) and Steady-State Spectral WAVE (STWAVE) models, the North Atlantic Coast Comprehensive Study mesh and grid were refined in the area surrounding Swan Island. The nodal attributes of the ADCIRC mesh in the area surrounding Swan Island were updated to reflect the location of submerged aquatic vegetation around the island. ADCIRC-modeled water levels were in acceptable agreement with observed water levels during both storms, though peak water levels were slightly underpredicted. Similarly, STWAVE captured the phase and trends of the significant wave heights during the storm, while slightly underpredicting both significant wave height and peak period. The validated model will be used to investigate the effect of the restoration of Swan Island on the surrounding area. The results will help to develop guidelines for best practices in island restoration within the Chesapeake Bay and beyond.

4 Jun 2025

Comprehensive Marsh Model Demonstration—Seven Mile Island Innovation Laboratory: Integrating Hydrodynamic, Morphodynamic, and Vegetation Modeling Components Using the Landlab Toolkit

Abstract: Marshes are highly dynamic landscapes that are shaped through feedbacks between hydrodynamic, morphodynamic, and ecological processes. Future marsh resilience is therefore dependent on the interaction between these different drivers rather than any individual piece. Marshes face a variety of threats, both natural and anthropogenic, resulting in a need for restoration actions that increase survivability. Because many of these threats are unprecedented or acting at unprecedented rates, statistical models do not adequately represent future conditions and require process-based models to better capture the complex interactions between both physical and ecological processes. This report demonstrates how to develop a comprehensive marsh model that integrates tidal flow, morphodynamics, and vegetation growth using the Python based Landlab toolkit. The model was applied to a site within the Seven Mile Island Innovation Laboratory complex in coastal New Jersey.

2 Jun 2025

Miami Harbor Entrance Channel Improvements Study: Ship Simulation Report

Abstract: The US Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory (ERDC-CHL), Ship/Tow Simulator (STS) was used to perform a navigation study assisting the US Army Corps of Engineers (USACE), Jacksonville District. The study evaluates additional navigation channel modifications from the previous 2019 study to allow larger containerships to call at the Port of Miami. This study was conducted at the CHL real-time STS. Real-time refers to the fact that model time uses a 1:1 ratio to prototype time. In addition, real-world environmental forces were simulated and acted upon the modeled ships during the study. These forces included currents, wind, bathymetry, and bank effects. Simulations for the proposed modifications were conducted at CHL for 1 week in August 2023. Four Biscayne Bay pilots participated in the validation and testing exercises. The design vessels include the MSC Daniela (14,000 twenty-foot equivalent unit [TEU]) container ship and the Maersk Guayaquil (12,000 TEU) container ship. Simulation results are presented in the form of track plots and pilot questionnaires, which were reviewed to develop the conclusions and recommendations.

19 Feb 2025

Lower James River Sediment Transport Modeling: Jordan Point

Abstract: US Army Corps of Engineers–Norfolk District (NAO) requested assistance from the US Army Engineer Research and Development Center (ERDC) to examine currently used placement sites within the James River, Virginia, initiative area, determine potential risk to critical environmental receptors during placement, and predict the life cycle of the placement sites. The focus of the analysis within this work is the Jordan Point placement site. The far-field, fate-transport modeling at Jordan Point shows relatively low maximum values of suspended sediment concentration (less than 40 mg/L) and deposition values (less than 0.2 cm). Material that is placed at Jordan Point appears to quickly disperse through the system, depositing in thin layers at specific areas. The life-cycle analysis performed for the Jordon Point placement site yielded an estimated useable project life of the Jordan Point placement sites of 26 years with an uncertainty of ±4 years. Analysis showed that 97% of the net sediment deposition in the navigation channel in proximity to this site is from the upper James River, 2% is from downstream sources, and 1% is from the two Jordan Point placement sites.