7 Apr 2025

Review of Mississippi River Sediment-Sampling Protocols

Abstract: The Mississippi River sediment data protocols located in the US Army Corps of Engineer (USACE), St Louis, Memphis, Vicksburg, and New Orleans Districts, were reviewed and evaluated. The review included both USACE and US Geological Survey (USGS) sampling sites. The purpose of this review was to evaluate the reported historical sediment data and to provide guidance for moving forward with an accurate and consistent sediment data collection program. The review was focused on the reliability of the reported historical data and its usefulness for use in sedimentation studies related to long-term aggradation, degradation, and dredging. Recommendations to implement effective sediment data collection, laboratory analyses, and reporting were provided.

2 Apr 2025

LaGrange Lock and Dam, Illinois River: Navigation Approach Physical Model

Abstract: A physical model study of the LaGrange Lock and Dam was conducted to optimize the navigation conditions for the new landside lock chamber design developed by the US Army Corps of Engineers–Rock Island District, Inland Navigation Design Center, and Stanley Consultants. A 1:120 Froude scale model was built to evaluate the navigation conditions for tows entering and exiting the upper and lower approaches. The final design consisted of a new 1,200 ft lock chamber located landward of the existing chamber. Data were collected to evaluate tow tracks and current direction and velocity information. Satisfactory navigation conditions were developed, and details are shown in the results section of this report.

12 Mar 2025

Collaborative Development of Natural and Nature-Based Solutions for Coastal Resiliency in the Arctic and Adjacent Regions: A Workshop

The workshop “Collaborative Development of Natural and Nature-Based Solutions for Coastal Resiliency in the Arctic and Adjacent Regions” was held in Reston, Virginia, October 24–25, 2023. The objective was to assemble diverse international partners in a hybrid in-person and virtual setting to focus on the viability of applying Nature-Based Solutions (NBS) to solve engineering challenges in the Arctic and similar cold region locations. The goals of the two-day workshop were to share recent efforts implementing NBS to mitigate coastal hazards such as flooding and erosion in northern high latitude settings and identify requirements and develop a robust program of activities to advance this work at national, regional, and local levels. This workshop report documents the presentations and discussion and summarizes key needs and recommendations for future engagement identified by speakers and workshop participants.

6 Mar 2025

Norfolk Harbor Navigation Improvements Project: Modeling of Dredged Material Placement Schemes and Long-Term Sediment Transport at the Dam Neck Ocean Disposal Site

Abstract: US Army Corps of Engineers–Norfolk District requested assistance with the development and evaluation of dredged-material-placement schemes that evenly distribute placed material and avoid or minimize unacceptable mounding in accordance with the site management and monitoring plan. A multiple placement fate and transport modeling study was conducted to determine the optimal placement plan for dredged material from Thimble Shoals Channel and Atlantic Ocean Channel at the Dam Neck Ocean Disposal Site (DNODS). Provided the large volume of dredged material to be placed at DNODS over a short duration during the construction period, a modeling study was performed using the Geophysical Scale Multi-Block (GSMB) modeling system to determine the transport and fate of placed dredged material at the DNODS that is resuspended by currents and waves over a 2-year period. Six scenarios were undertaken to determine the best path forward. Scenarios 1 and 4 were excluded due to high exceedance of the depth threshold. Scenarios 2, 3, 5, and 6 yielded an approximate 1%–2% dispersal of placed materials from the DNODS during ambient environmental conditions; Scenario 6 yielded the least. Most dispersion occurred during two simulated hurricanes. The model findings generally support the DNODS Environmental Impact Statement and site-designation documents.

3 Mar 2025

Low-Sill Control Structure: Physical Modeling Investigation—Potential Upstream Dike Fields

Abstract: The model investigation reported herein describes the process to analyze the effects of proposed dikes in various locations upstream of the Low-Sill Control Structure (LSCS) using an existing 1:55 Froude-scaled physical model. The purpose of this effort was to utilize the physical model to explore potential configurations of river-training structures in the approach channel that would result in more uniform flow conditions at the structure. This analysis was conducted by constructing dikes out of both sandbags and rock. Each dike configuration was surveyed using lidar and then tested by collecting particle-tracking velocimetry data. A total of nine dike configurations were tested in the physical model, and the resulting flow fields in the approach channel were provided to the US Army Corps of Engineers, Mississippi Valley Division. Most configurations resulted in data that showed improved, straighter flow paths in the approach channel. The results of these tests indicated that an L-head dike configured as the 50 ft stone dike 1-23A provided relatively straight flow conditions approaching the LSCS with relative uniform velocities across the channel.

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.

14 Feb 2025

Validating Sediment Budgets Along the North Atlantic Coast Using the Updated Sediment Budget Calculator

Purpose: This Regional Sediment Management (RSM) technical note (TN) outlines two case studies validating the Sediment Budget Calculator (SBC) using accepted values from the literature and published sediment budgets. Initially developed by the US Army Corps of Engineers (USACE) as a web-based tool, the SBC calculates all viable sediment transport rates for an inlet environment given user-defined inputs. The next-generation SBC was converted into Python 3.9 to make it more accessible than the original C++ version. These case studies outline the efficacy of the SBC tool for deriving accurate and reliable sediment budget values. Finally, the TN discusses future SBC improvements and efforts to incorporate SBC results into the Sediment Budget Analysis System (SBAS).

13 Feb 2025

Upper Barataria Basin (UBB) Coastal Storm Risk Management (CSRM) Study : Probabilistic and Numerical Coastal Hazards Modeling

Abstract: This report summarizes the numerical modeling and probabilistic analysis performed by the US Army Engineer Research and Development Center Coastal and Hydraulics Laboratory (CHL) as part of the Upper Barataria Basin (UBB) Coastal Storm Risk Management (CSRM) Study. The intent of this work, performed for the US Army Corps of Engineers (USACE) and St. Paul District, was to evaluate project alternatives to assess flooding risks induced by coastal storms in coastal Louisiana. This study applied the USACE’s Coastal Storm Modeling System for storm surge and wave modeling and Coastal Hazards System–Probabilistic Framework (CHS-PF) to quantify water level and wave hazards, leveraging existing synthetic tropical cyclones (TCs) from the Coastal Hazards System¬–Louisiana (CHS-LA) study for levee recertification. Using a reduced storm suite (RSS) of synthetic TCs from CHS-LA, hydrodynamic model simulations were performed on an updated grid, including five proposed levee systems, to produce storm responses at more than 184,000 mesh node locations and over 21000 special save point locations within the UBB project area. Through the application of the CHS-PF, the joint probability analysis of TC atmospheric-forcing parameters and their associated storm responses were assessed for the estimation of still water level (SWL), significant wave height (Hm0), and wave peak period (Tp) annual exceedance frequencies ranging from 10 to 1 × 10−4 yr−1 to evaluate the impact of the UBB with- and without-project conditions.

12 Feb 2025

Cloud-Based Workflow to Process Regional Topobathymetric Lidar Datasets for Integrated USACE Shoaling Analyses

Purpose: This Coastal and Hydraulics Engineering Technical Note (CHETN) details a methodology to process and format regional topobathymetric datasets for use in the US Army Corps of Engineers (USACE) Corps Shoaling Analysis Tool (CSAT).

28 Jan 2025

Montgomery Locks and Dam, Ohio River: Navigation Approach Physical Model

Abstract: A physical model study of the Montgomery Locks and Dam was conducted to optimize the navigation conditions for the new riverside lock and guard wall design developed by the Pittsburgh District. A 1:100 Froude scale physical model was built to evaluate the navigation conditions for tows entering and exiting the locks in the upstream and downstream approaches. Conditions tested were Existing Conditions, Deconstruction Sequences, Construction Sequences, and Proposed Design. Data were also collected for impact analysis on the upstream and downstream riverside guard walls. The final design consisted of an upstream ported guard wall that is 1,000 ft in length and a downstream solid guard wall that is 800 ft in length. The implementation of submerged dikes in the upstream and downstream approaches improve navigation conditions significantly and are an essential part of the final design. Details are shown in Section 3.5 of this report.