12 Aug 2026

Lifecycle Analyses of Subaerial Beach Nourishments with Concurrent Nearshore Placement of Dredged Sediment and the Role of Alongshore Transport

Abstract: Beach nourishment has a high cost but offers large economic benefits. Therefore, extending the nourishment lifespan using dredged sediment from navigation channels could have a significant economic impact. This numerical modeling study develops and compares two approaches incorporating nearshore sediment placements into an existing one-dimensional numerical modeling procedure to predict the lifespans of subaerial beach nourishment strategies. Both approaches build directly on the stochastic lifecycle simulation methodology and results used in the Coastal Texas Protection and Restoration Feasibility Study. Simulations for western Galveston Island were modified to include annually recurring nearshore nourishment. Cross-shore beach transects were forced with 50 years of tropical cyclones and nontropical storms in a cross-shore morphological evolution model, and rebuilt when the dune eroded to half of its initial height. One group of simulations applied this previously developed model forcing to cross-shore profiles that were updated with recurring nearshore nourishments. A second group of simulations included a simplified representation of sediment deposition from the along-shore transport gradient created by the nearshore nourishments. In both sets of simulations, a large sediment feature was incrementally constructed at depths between 2.5 and 6 m. Over 30 life cycles, the number of times the beach was rebuilt was tracked for each 50-year simulation. Comparing the number of predicted beach renourishments indicates that this particular nearshore nourishment strategy did not substantially impact the subaerial beach morphology unless alongshore transport gradients were also included. Simulations that did include this alongshore transport gradient predicted 23% longer lifespans. This work was not able to incorporate validation against measured data, but future testing of this approach should be pursued before widespread or high-impact application. Modeling results indicate that along-shore processes are an important part of quantifying the positive impacts of nearshore nourishment.

4 Aug 2026

Modeling Evaluation of a Bird Island Design in Hampton Roads, Virginia

Abstract: This report documents a numerical modeling investigation on the sediment transport and morphology changes surrounding designed marine habitats for seabirds in Hampton Roads, Virginia. It assembles and analyzes historical and newly collected wave and hydrodynamic data from the study area. The datasets are used to calibrate and validate coastal wave, hydrodynamic, and sediment transport models. It describes developments of model alternatives that correspond to different bird island designs. It evaluates current and sediment transport fields and seabed volume changes around the island under a representative normal year (2020) and under a storm simulation condition for a 50 yr return synthetic storm with corresponding sea level rise. Model simulations show weak current and sediment transport fields prior to the island construction. With alternative designs of the island, model results show significant changes in magnitudes and spatial distributions of current and sediment transport rate. Analysis of model bed volume changes demonstrates different erosion and deposition trends under the normal environment and under the storm simulation condition. The island design and configuration, including island orientation, island slopes, and material coverage, respond differently to the impact of physical forcing applied in the modeling.

26 Jun 2026

Water Quality and Sediment Dispersal from Placement of Dredged Material over Former Shell Mining Beds in Mobile Bay, Alabama

Abstract: The US Army Corps of Engineers (USACE) continues to advance regional sediment management practices including Beneficial Use of Dredged Material (BUDM) to reduce dredging costs while improving outcomes for coastal communities and ecosystems. This report describes two field studies conducted to better understand sediment retention and water quality implications associated with in-bay strategic placement of dredged material within former oyster-shell mining areas within Mobile Bay, Alabama. Deployed instrumentation and periodic campaigns of bed and water quality sampling provided data prior to dredged-sediment placement through more than a year after placement. Bed sampling and acoustic sub-bottom profiling indicated that the dredged material deposit was spatially variable in thickness and composition. Placed sediment accumulated quickly, within hours of placement, followed by a 2–4 month period with relatively small adjustments. Beyond 6 months, bed elevation changes became stable at near-background levels. Water quality data indicated that impacts to dissolved oxygen and turbidity associated with the dredged material placement are minor and short-lived. Notably, all water quality parameters remained within the normal range of variability observed within the dynamic Mobile Bay ecosystem. Collectively, these sediment bed and water quality studies support future data driven BUDM decision-making within the Mobile Bay region.

12 Jun 2026

EcoHydraulic Modeling to Inform Sustainable Sediment Management: A Priori Modeling of Reservoir Sediment Release to Estimate Geomorphic and Ecological Response

Abstract: With decreasing storage capacity and increasing operational costs in reservoir management, sediment release is considered a potential alternative to traditional dredging. However, passing sediment through reservoirs may have unexpected effects on downstream river morphology and ecosystem resources. This study uses numerical modeling and a conceptual ecological model to assess the relative effects of sediment load, stream flow magnitude, and grain size distribution in downstream river morphology and aquatic habitat in a case study system of the Big Blue and Kansas Rivers downstream of Tuttle Creek Reservoir, Manhattan, Kansas. The effects of sediment grain size, clearwater flushing rate, and backwater effects from the Kansas River were all found to be relevant in affecting sediment transport and deposition patterns. High-volume water/sediment releases were found to be most effective at emulating historical conditions. Additionally, sediment release was found to increase desirable physical habitat areas that have been lost in the channel. Clearwater flushing further increased the distribution of sediment to support physical habitat creation. These findings can inform sediment release management decisions regarding the timing, duration, and magnitude of sediment releases, particularly in relation to flows at the downstream confluence and for target ecosystem function goals.

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.

5 Jun 2026

Multitemporal Change Detection in the Coastal Zone: Literature Review

Abstract: Beach volume change is a primary metric for quantifying coastal change due to physical and anthropogenic forces. Volumes provide key inputs for the creation and maintenance of regional sediment budgets that inform engineering decisions and ensure the effective management of sediment. This special report provides a comprehensive literature review of the state of the art for developing beach volume change metrics, including methods, software and tools, and common sources of error. The reviewed literature indicates that common proxy-based methods for developing volumes (e.g., shoreline change analysis and beach profile change analysis) are limited in their applicability for study areas with alongshore geomorphic variability. A digital elevation model (DEM) of difference method used with high-resolution (e.g., 1 m DEM) datasets captures volumes over spatially variable geomorphologies more accurately; however, the literature notes limitations related to elevation dataset coverage and geometries used for aggregating volume quantities. Space-time cube methods enable cell-by-cell comparisons of volumes over multiple time periods within defined neighborhoods and provide additional insights, efficiencies, and flexibilities to afore-mentioned methods. A new beach volume framework is required to address limitations related to geomorphic variability, aggregation units, and dataset coverage.

21 May 2026

Evaluation of Shore Protection Alternatives at Crescent Beach, Indiana

Abstract: This report documents a numerical modeling investigation of shore protection alternatives at Crescent Beach, Indiana. The integrated flow, wave, sediment transport, and morphology change Coastal Modeling System (CMS) and the long-term shoreline evolution model, GenCade, were applied to evaluate alternatives. Sediment, elevation, and hydrodynamic data were collected nearby to improve model calibration and validation. Eight alternatives were evaluated, with coastal structures in four, beach nourishments in three, and one with both. Structures other than the continuous rubble ridge (Alternative 4) had minimal or negative influences on sediment transport. Stone sizes and costs were estimated for Alternative 4 using StormSim and extremal forcing from the Coastal Hazards System (CHS) Great Lakes Study, but CMS does not predict impacts that justify rubble ridge construction costs. CMS and GenCade were applied to beach nourishments across a range of volume and sediment grain size distributions. Model evaluations indicate that beach nourishment is the most effective shoreline protection technique, using coarse sand mixed with small stones to achieve a median grain size (d50) of 1.80 millimeters successfully extends the beach nourishment lifecycle, and increasing nourishment volume to 87,455 cubic meters to span in front of Mount Baldy substantially increases downdrift benefits.

27 Apr 2026

Beneficial Use and Sources of Shoaled Material at Kahului Harbor

Abstract: Ongoing sediment shoaling in Kahului Harbor is detrimental to navigation as it creates a hazard to vessels operating within the Harbor and necessitates recurring maintenance dredging. This study addressed two aspects of the shoaling in Kahului Harbor. First, the volume of shoaling sediment was estimated based on this and previous research efforts in Kahului Harbor, and the material was evaluated for potential beneficial use as beach placement material. Second, sedimentary geochemical fingerprinting including elemental composition, grain size, and sediment color was assessed and compared to potential terrestrial sources to identify the source of the shoaling sediment for potential future mitigation studies. Results determined that the size and color of the shoaling sediment was not conducive for beach placement and thus would not have a beneficial use aspect unless a need could be identified for fine-grained dark-colored sand in an upland region. Additionally, results identified western Maui as the dominant source of shoaling sediment in Kahului Harbor, likely via high flow events in the Iao Stream. Further studies are suggested to both identify potential uses for the shoaled sediment, as well as to better quantify sediment transport pathways from West Maui into Kahului Harbor to identify potential mitigation strategies.

24 Apr 2026

Conceptual Sediment Budget Creation Using CorpsCam Imagery: Holland Harbor, Michigan

Abstract: This Regional Sediment Management (RSM) technical note (TN) discusses the development of a conceptual sediment budget at Holland Harbor, Michigan, using CorpsCam imagery. Imagery from May 2020 through October 2021 was analyzed to calculate volume change along Ottawa Beach, just north of the entrance to Holland Harbor. Shoaling rates and longshore sediment transport rates were calculated to supplement the beach volume change rates, with a sediment budget developed as the final product. This is a companion piece to the ERDC/TN RSM-26-1, Conceptual Sediment Budget Creation Using CorpsCam Imagery: Lynnhaven Inlet, Virginia.

24 Apr 2026

Conceptual Sediment Budget Creation Using CorpsCam Imagery: Lynnhaven Inlet, Virginia

Abstract: This Regional Sediment Management technical note (RSM TN) discusses the development of a conceptual sediment budget at Lynnhaven Inlet, Virginia, using CorpsCam imagery. Analysis of imagery collected between September 2022 and July 2024 is used to calculate the volume change along the beaches adjacent to the inlet. The final budget incorporates shoaling change rates and estimated longshore-sediment transport rates. This is a companion piece to the ERDC/TN RSM-26-2 Conceptual Sediment Budget Creation Using CorpsCam Imagery: Holland, Michigan.