29 Sep 2025

State of Practice and Recommendations to Enhance Probability of Failure Estimates for Civil Works Infrastructure Components

Abstract: As the US Army Corps of Engineers (USACE) continues to improve its asset management system, it is imperative that maintenance investments across its wide infrastructure portfolio are maximizing risk reduction. A key component of risk is probability of failure. Presently, USACE estimates probability of failure for asset components in a variety of ways across business lines, activities, and decision spaces. This document explores the variations in the state of practice for probability of failure estimates across USACE and contrasts them with available best practices and methodologies. The review found several key gaps between the state of practice and best practices, including a lack of component failure and life data useful for time-to-failure parameter estimates, a lack of codified definitions of failure, no clear and consistent guidance for probability of failure estimates across business lines or decision spaces, and no methodologies that account for environmental variation at a facility. These gaps are addressed by a research strategy that compares and contrasts several probability of failure calculation methods using presently available data, identifies relevant life data for future collection, and defines a framework for investing in improved probability of failure assessments at facilities.

29 Sep 2025

River Training Structure Design Study for Stabilization at Bonanza Bar

Abstract: The Huntington District (LRH) has repeatedly dredged within the navigation channel at Ohio River Mile (RM) 353, adjacent to a location known as Bonanza Bar. An in-channel bar has developed from the placement of the dredged material along the left-descending bank where a bar was historically present. Recently, the frequency of dredging in this area has decreased, suggesting that the presence of the bar is providing some degree of channel constriction. LRH approached the US Army Engineer Research and Development Center to model possible river training structures to provide channel constriction and stabilize the placement of dredged material at Bonanza Bar. A two-dimensional hydraulic numerical model was developed to test structural alternatives by estimating the impacts on the velocities within the main channel, along the length of the bar, and along the mussel habitat within the side channel. Various rock dikes with bank protection were modeled and general design guidance and modeling results are presented. Modeling results indicate increases in main channel velocities and decreases in flow behind the structure for all modeled alternatives. Rootless dikes and bullnose chevrons provide adequate space and flow for side channel presence as opposed to the continuous and notched dikes.

26 Sep 2025

Rapid Assessment Tool for Channel Hydraulics and Floodplain Connectivity

Abstract: This technical note (TN) presents a rapid, nationally applicable web application for analyzing channel hydraulics and floodplain connectivity. The tool uses locally derived relative elevation models (REMs) that allow users to quantify hydraulics, like velocity and shear stress, and floodplain connectivity metrics, like inundation extent and storage volume (Haring and Dougherty, forthcoming).* By delineating cross sections directly from publicly available high-resolution terrain, the tool provides a rapid hydraulic assessment without requiring field survey data and also helps prioritize reaches for more detailed assessments.

25 Sep 2025

Evaluation of the Coastal Hazards System (CHS) Probabilistic Framework’s Storm Selection Methods Along the US West Coast

Purpose: This Coastal and Hydraulics Engineering Technical Note (CHETN) evaluates the application of a traditional approach to screening and sampling historical storm events to quantify wave and water-level extremal distributions along the US West Coast, specifically focusing on Washington, Oregon, and California. High-fidelity simulations of storm events enable spatially explicit waves and water-level information in shallow nearshore regions, providing greater context than single-point tide gauges, wave buoys, or hindcast wave nodes in offshore waters. However, the computational expense associated with such simulations necessitates that a select number of events be chosen, ideally representative of the same extreme distribution created by the complete history of storms. Storm selection has previously been shown to be sensitive to the observational record length and the storm sample size but notably also region-specific characteristics such as the common (and uncommon) synoptic weather patterns and the alongshore variability of metocean conditions. The US Army Engineer Research and Development Center (ERDC), Coastal Hazards System (CHS), Stochastic Simulation Technique (SST), which was developed for the quantification of extratropical cyclone (XC) hazards based on extreme value analysis techniques, has previously been used to identify storms for high-fidelity simulations in several regions throughout the United States, including the Great Lakes (Nadal-Caraballo et al. 2012), US mid- and North Atlantic (Nadal-Caraballo et al. 2014; Nadal-Caraballo et al., “North Atlantic Coast,” 2015; Nadal-Caraballo et al., “Statistical Analysis,” 2015), and US South Atlantic (Yawn et al. 2024b) and Gulf of Mexico (Yawn et al. 2024a). However, coastal hazards for the US West Coast and the Pacific Basin are a consequence of multiple compounding oceanographic, meteorologic, and climatic phenomena contributing to waves and water levels with unique characteristics compared to tropical cyclone–dominated coasts. This effort defines total water levels as a combination of still-water levels (SWLs), incident wave runup, and infragravity runup as a proxy for the water elevation experienced at the shoreline during storm events. Dynamic total water levels during extreme events are then separated into individual contributions from oceanic and meteorological phenomena occurring at a variety of timescales, such as seasonal and monthly sea-level anomalies. Results from this analysis highlight future SST developments that will be required as part of a comprehensive CHS-Probabilistic Framework (CHS-PF) for the US West Coast and the Pacific Basin. Specifically, the methodology will need to (1) account for temporal clustering of storm sequences, (2) align with the parameters most relevant to US West Coast coastal storm risk management projects, and (3) develop an approach to create composite storm suites derived from extremes in multiple metocean parameters due to limited overlap between those storms that produce extremes in still water and those storms driving open-coast wave-induced extremes.

23 Sep 2025

Physical Model Evaluation of the Yazoo Backwater Pumping Plant: Pump Intake Model Study

Abstract: The Yazoo Backwater Area, located in west Central Mississippi, has historically experienced major flood events caused by high floodwaters from the Mississippi River and interior rainfall accumulation. To manage this, the US Army Corps of Engineers, Vicksburg District (MVK) proposed the construction of a 12-pump, 14,000-cfs-capacity pump station. The pump intake performance of the proposed pump station was evaluated using a scaled physical hydraulic model. The 1:17.62-scale model incorporated the hydraulically relevant components of the design including the inlet channel, all 12 intake bays with formed suction intakes and pump columns, abutments, and surrounding topography. Various pump-operating conditions and intake water-surface elevations were evaluated for acceptable pump performance. Approach-flow conditions were generally symmetrical with minor contraction at the intake divider walls. The outer pump bays produced a less uniform flow distribution. Surface vortices were found to be unacceptable for several pump-operating conditions at the minimum-intake water elevation (EL) and pump-on water-surface elevation. Tests indicated that vortex suppressor beams would be required in the pump bays to reduce the severity and frequency of surface vortices. With the beams installed, the pump intakes provided satisfactory hydraulic performance for the approach-flow conditions.

23 Sep 2025

Using the Robot Operating System for Uncrewed Surface Vehicle Navigation to Avoid Beaching

Abstract: Our research explores the use of the Robotic Operating System (ROS) to autonomously navigate an uncrewed surface vehicle (USV). As a proof of concept, we set up a simulated world and spawned a virtual Wave Adaptive Modular Vehicle (WAM-V). We used the robot_localization package to localize the WAM-V in the virtual world and used move_base for the navigation of waypoints. The move_base package used both costmaps and path planners to reach its intended goal while simultaneously avoiding sub-merged shallow-water obstacles. Shallow-water obstacles are obstacles at a depth that is less than a user-defined value (1 meter in this case). Finally, we investigated using vizanti as a mission planner. This report provides a detailed explanation of the parameters that were modified to demonstrate a successful proof of concept.

23 Sep 2025

Wave Kinematics-Based Bathymetry Estimates from Satellite Optical Video

Abstract: Here, cBathyShortDwell, a version of the spectral depth inversion algorithm cBathy adapted for shorter record lengths, was applied to four 29.9-60s satellite-based optical videos and the resulting bathymetry estimates were compared to surveys collected within 13 days of each satellite collect. The Planet SkySat videos were collected at the ERDC Field Research Facility between April and September 2023. The videos were collected at 30Hz with a ground sampling pixel resolution of 0.75-1 m and an image size of approximately 2.5km x 1km. RMSEs from post-processed cBathyShortDwell depth estimates over the 800 m x 1100 m analysis domain using the entire video duration at a 5 Hz frame rate ranged from 0.50 to 0.59 m with biases ranging from -0.19 to 0.16 m. Although some differences were seen in the RMSEs as a function of frame rate, larger differences were observed due to video length, wave visibility in the imagery, and incident wave conditions. The highest RMSEs were observed in short video lengths or low wave visibility. These results are comparable to published RMSE values from established versions of the algorithm and demonstrate the ability of cBathyShortDwell to provide good depth estimates from satellite videos in a range of environmental conditions.

19 Sep 2025

Natural and Nature-Based Features (NNBF) Design Process

Purpose: The US Army Corps of Engineers (USACE) provides water resource and river engineering technical support to a wide-ranging portfolio of projects across the country and world. To maintain state-of-the-art river engineering practice, research and development focused on updating conventional river engineering technologies and approaches is required. Incorporating Natural and Nature-Based Features (NNBF) and Natural Infrastructure (NI) strategies into the design of stable channels is one way to update river engineering practices (USACE 2017). The objective of this technical note is to provide a standard approach for incorporating NNBF-NI into the design of stable channels. Specific analysis and design details referred to herein are part of the NNBF Stabilization and Restoration (NNBF-SR) research and development (R&D) effort.

16 Sep 2025

Quality Control for Waterway Networks: Processing Algorithm and GIS Toolbox

Purpose: This Coastal and Hydraulics Engineering technical note (CHETN) documents the development of a US centered Geographic Information System (GIS) representation of navigable waterways for research purposes, including connections with the US Army Corps of Engineers (USACE) National Channel Framework (NCF) reaches, depths, and international connections, and the “Quality Control for Waterway Networks” processing algorithm. The algorithm is an automated method to update a waterway network created by the Coastal and Hydraulics Laboratory (CHL). After a user introduces desired changes to an input line layer representing waterways, the algorithm outputs links and nodes’ shapefiles containing a fully connected network, with geometries and depths aligned with the NCF, and controls for topology and attributes quality. In addition, spatial joins assign attributes to network nodes from other various sources of data. The product of this work is a GIS waterway network, along with a Quality Assurance and Quality Control (QAQC) script incorporated via toolbox within an open-source GIS software to maintain the waterway network updated. The algorithm has the capacity to be adapted to other transportation network needs or GIS software packages.

12 Sep 2025

Arkansas City to Vicksburg Adaptive Hydraulics Model

PURPOSE: The purpose of this study is to develop and validate a 2D, depth-averaged hydrodynamic model of the Mississippi River from Vicksburg, Mississippi, to Arkansas City, Arkansas, to accurately replicate low-flow conditions. The model will be used to support an ongoing effort for the development of a low-water forecast model to aid navigational resilience.