25 Aug 2026

Hydrodynamic Mechanisms and Pathways of Potential Navigation Channel Shoaling by Nearby Parallel Islands

Abstract: As the demand for transcontinental commerce has increased over the past century, navigation channels have been maintained at increasingly greater depths to continue access of deep draft vessels to inland ports. Over time, these deep navigation channels require routine dredging to counteract the gradual processes of sedimentary accumulation, known as shoaling, that can enter the channel from terrestrial or oceanic sources through natural (e.g., tides, streamflow, runoff) or anthropogenic (e.g., vessel wake) processes. To limit the cost of moving the dredged material to upland or offshore storage facilities and to prevent long-term sediment loss from the system, the material can instead be reused locally to build marsh or island habitats. While the various environmental impacts of keeping and reusing the material within the sourcing embayment have been investigated at length, the hydrodynamic impacts of large-scale within-embayment placements have previously been understudied, particularly regarding potential changes to navigation channel shoaling. In this work, we use numerical models to investigate how channel-parallel linear island features may modify sediment transport mechanisms and pathways, and discuss long-term shoaling implications. Based on the various tested channel and embayment geometries, taken from nautical charts detailing the evolving topobathymetric history of Lake Calcasieu and the Calcasieu Shipping Channel (Louisiana, USA), linear and near-continuous islands are shown to have the potential to increase sedimentation in the channel by altering both local hydrodynamics around the islands and estuarine-scale tidal dynamics. However, the degree to which the islands are continuous and the dominant forcing factors are shown to limit the increase in shoaling likelihood by island presence.

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.

17 Jul 2026

Improved Beneficial Use of Dredged Material (BUDM) Laboratory Methods for Low-Stress Consolidation

Abstract: The purpose of this Dredging Operations and Environmental Research (DOER) Program technical note (TN) is to present the improved laboratory methods for low-stress consolidation to support the beneficial use of dredged material (BUDM). Despite the growing practice of BUDM to support coastal environments, significant knowledge gaps persist in the behavior (e.g., consolidation and erodibility) of hydraulically placed cohesive sediments. The consolidation of deposited sediment dictates the resultant surface elevation, a key design component controlling the hydroperiod and shear strength of wetland ecosystems, which are key indicators of the long-term health and stability of the wetland. The existing US Army Corps of Engineers (USACE) consolidation testing of ultrasoft materials utilizes settling columns that rely on highly time-consuming, experimental laboratory methods that are prone to human-induced errors. Therefore, an updated laboratory methodology that incorporates scientific advancements to manage consolidation and erodibility measurements is essential to providing practical testing with a higher degree of certainty for BUDM designers and ultimately helping to support USACE’s goal of reaching 70% BUDM.

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.

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.

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.

23 Apr 2026

Sediment Transport Modeling to Evaluate the Performance of a Dredged Channel at Pohoiki Bay, Hawaiʻi, Following the Kīlauea Lower East Rift Zone Eruption

Abstract: The Kīlauea volcano’s Lower East Rift Zone (LERZ), located approximately 20.5 miles south-southeast from Hilo on the Island of Hawaiʻi, erupted during the summer of 2018, destroying over 700 homes and advancing the shoreline east of the volcano into the Pacific Ocean. The recently formed lava field along the shoreline eroded into Pohoiki Bay, creating a black sand beach that closed access to a boat ramp that was vital to the local community. The US Army Corps of Engineers (USACE) Honolulu District, on behalf of the State of Hawaiʻi, requested the US Army Engineer Research and Development Center (ERDC) Coastal and Hydraulics Laboratory (CHL) conduct numerical modeling of the existing condition at and around the bay to evaluate the impact of dredging a channel through the beach to reconnect the boat ramp to the Pacific Ocean. The Coastal Modeling System (CMS) was used to evaluate the shoaling rates in the proposed channel. The model was validated with morphology change calculations from a sediment budget, and the results provide a range of possible shoaling rates in the channel. The results of this effort were used to inform the State of Hawaiʻi’s plans to complete construction of a dredged channel in November 2025.

22 Apr 2026

Juvenile Atlantic Sturgeon Survival and Movement in Proximity to an Active Cutterhead Suction Dredge

Abstract: The Atlantic Sturgeon Acipenser oxyrinchus oxyrinchus has suffered population declines throughout its range. Many knowledge gaps exist regarding how to mitigate threats and better inform recovery efforts. This study examined survival of juveniles during their movements through river reaches undergoing channel maintenance dredging operations. During 2019 and 2020, 268 (30-71cm fork length) juvenile Atlantic Sturgeon were captured and released in proximity to an active cutterhead suction dredge at three sites within the James River, Virginia. Juveniles were captured, some presumed feeding, around 95-145m from the dredge in areas that could easily be avoided if the dredge created a stressful environment. No significant trends in catch-per-unit-effort were found when trawl catch was compared to a reference location or when monitoring gill net catch 100m down current of a dredge over a month-long period at one of the sites. Twenty-nine of the 229 gill net captures were implanted with acoustic tags and telemetry was used to track their movements throughout the river. Four telemetered juveniles tagged prior to this project were also detected moving within dredge operations. Cumulatively, tagged juveniles made at least 125 passes of the dredging operations with no evidence of mortality. All tagged juveniles still within the river were detected following the cessation of dredging. The results of this study support that age 1-2yr Atlantic Sturgeon show no avoidance behavior of areas 100m of an active cutterhead suction dredge and move past dredge operations with low-risk of mortality.

30 Mar 2026

Water Injection Dredging—Screening for Suitability: Research and Development of Screening Criteria to Determine the Suitability of Water Injection Dredging

Abstract: Innovative technologies for sediment management could reduce dredging costs and enhance benefits from sediment resources. Water injection dredging (WID) has the potential to improve sediment management in channels and reservoirs in the United States, but conditions for feasibility and favorable applications must first be established. WID works by fluidizing a sediment bed, causing it to flow down gradient or to spread as a density current. Fluidization testing on a range of sediments shows that the liquidity index might be an effective indicator of a sediment’s susceptibility to fluidization via WID. To assess the anticipated effectiveness of WID, a series of experiments were conducted to evaluate the fluid mud properties of sediment from Tuttle Creek Lake, Kansas, where WID has been proposed for reservoir management. Laboratory investigations were conducted to evaluate settling characteristics, viscosity, and angles of repose of the fluid mud over a range of concentrations. Large-scale flume experiments were also conducted to track the velocity and slope of the density current. Results were used to evaluate the flow characteristics of a density current generated by WID.