11 Jun 2026

Simulation of Dredged Material Placement in the San Francisco Bay Using a Multi-Dimensional Hydrodynamics and Sediment Transport Model

Abstract: The US Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory, has developed an Adaptive Hydraulics (AdH) 2D, hydrodynamic and sediment transport model for San Francisco Bay. This model supports the US Army Corps of Engineers, San Francisco District, in informing navigation and sediment management decisions as part of the Regional Dredged Material Management Plan (RDMMP), which evaluates dredging methods and placement alternatives over a 20-year planning horizon. There is a need to assess the long-term fate of dredged material placed at in-bay sites to better understand associated benefits and potential impacts. This report documents the development, calibration, and validation of the AdH 2D model for conditions in 2022. The model was applied to simulate the multimonth dispersion and transport of dredged material from four sites. Model results demonstrate that sediment transport patterns are influenced by seasonal hydrodynamic forcing and grain-size composition, with coarser material forming stable deposits that persist over time. The findings of this study inform sediment management strategies under the San Francisco Bay RDMMP and support efforts to reduce navigation risks and enhance beneficial use opportunities. The study recommends field data collection to improve sediment characterization at placement sites and strengthen predictive modeling and planning efforts.

11 Jun 2026

The Bird Islands Ecosystem Design Using Boussinesq Modeling—Barren Island, Mid-Chesapeake Bay

Purpose: The US Army Corps of Engineers (USACE) Baltimore District is currently engaged in an ecosystem restoration within the Chesapeake Bay, Maryland. Specifically, two islands, Barren Island and James Island, are to undergo restoration using dredged materials and creation of berms and breakwaters to offer a level of protection to the island from wave and surge during storm events. This report focuses on the design of bird habitat development on the Tarbay side of the detached breakwaters in the Barren Island design. During the ongoing Preconstruction, Engineering, and Design (PED) phase of the project, it was determined that terraced islands would be created on the leeside of the detached breakwater system for bird habitat development. Coastal storm inundation and wave loading from Coastal Storm Modeling System (CSTORM-MS) coupled surge and wave modeling system were quantified in a previous effort. These results are used as input to local high-fidelity phase-resolved wave modeling to quantify the hydrodynamics on the island. The terraced structure will include berms. Berm and breakwater stone stability was quantified using Ahrens (1989) reef equations. This report discusses potential erosion and additional structure configurations. Additional offshore reef-type breakwaters were considered to protect the bird islands from waves propagating from the east to the west toward the Tarbay side of the island.

26 Mar 2026

Development of a Three-Dimensional (3D) Hydrodynamic, Salinity, and Sediment Transport Model of the San Francisco Bay

Abstract: The US Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory (ERDC-CHL), has developed the multimodule Adaptive Hydraulics (AdH) model for San Francisco Bay, incorporating hydrodynamics, salinity, and sediment transport. This model supports the US Army Corps of Engineers San Francisco District in navigation and sediment management, particularly for the development of a Regional Dredged Material Management Plan to assess dredging methods and placement alternatives. San Francisco Bay is a dynamic estuary shaped by strong tidal currents, seasonal freshwater inflows, and complex sediment transport. As a key hub for international maritime trade, its federal navigation channels require regular maintenance dredging. Dredged sediment plays a crucial role in sustaining mudflats, tidal marshes, and intertidal habitats that mitigate coastal flooding and provide ecological benefits. This report documents the development, application, and validation of the AdH-3D model for 2022, demonstrating its ability to reproduce observed hydrodynamic, salinity, and sediment conditions. It details the model setup, boundary conditions, and validation, ensuring its reliability for informing sediment management and navigation planning. The model serves as a valuable tool for evaluating long-term sediment fate and optimizing regional dredging strategies.

18 Feb 2026

Mesh Convergence Study of Adaptive Hydraulics (AdH) Version 5.9

Abstract: This report details performance and convergence tests of the Adaptive Hydraulics (AdH) v5.9 software suite on the Engineer Research and Development Center ONYX Cray X40/50 supercomputer. In particular, the performance of a recently developed monolithic model coupling AdH framework between the Richards equation for variable groundwater and surface water flows or for overland sloped conditions is studied. The effort is part of a quality assurance test of a recently restructured version of AdH. The report also includes a scalability analysis of AdH on a Cray system.

10 Dec 2025

Evaluation of Vegetated Shoreline Capacity Using CSHORE-VEG

Abstract: A versatile vegetation module has been implemented into the Cross-Shore model (CSHORE) to evaluate the capacity of coastal and marine wetlands with respect to wave-height attenuation and wave-runup reduction. This extended model, Cross-Shore-Vegetation (CSHORE-VEG), is capable of simulating the effects of rigid and flexible vegetation with spatially varying biomechanical properties. To accurately estimate the vegetation-induced energy dissipation rate, a drag coefficient formula that is independent of the vegetation flexibility was developed based on field data collected in salt marshes in Terrebonne Bay, Louisiana, during a tropical storm. This universal drag coefficient formula along with other existing drag coefficient formulas have been implemented into CSHORE-VEG to meet different needs. CSHORE-VEG has been validated against four independent datasets involving different vegetation properties for wave attenuation and mean water level change. After achieving good agreement in model-data comparisons, CSHORE-VEG was employed to quantify the capacity of two representative salt marshes composed of Spartina alterniflora and Elymus athericus for wave attenuation. As a result, two ineffective vegetated shoreline scenarios were identified. Furthermore, a procedure for determining the percentage of broken vegetation stems and modeling the corresponding wave-height reduction was applied to evaluate the wave-height reduction under realistic field conditions.

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.