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.

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.

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.