29 Jul 2025

Engineering Practice Guide for Floodplain Benching: A Natural Infrastructure Approach for Riverine Systems

Abstract: Floodplain benches are a potential solution for inland river systems where out-of-bank flooding generates unacceptable flood risk and access to riverine floodplains has become restricted over time. Benches are a naturally forming geomorphic feature between the riverbed and a higher floodplain or terrace. In addition to reducing flood risk, benches reduce erosion risk, improve aquatic ecosystems, enhance plant and wildlife diversity, expand recreational opportunities, and may be places of cultural and tribal value. This document informs engineering activities related to site investigation and design of floodplain benches. It is intended to be used by engineers and ecologists to inform the design of floodplain benches in a manner that is consistent with and augments other planning, design, and engineering guidance. A well-designed floodplain bench can improve ecological and biological functions while also reducing flood risk by creating a channel in geomorphic equilibrium with current conditions and resilience to anticipated changes in hydrology and sediment supply rates. This publication is among a series of planned technical reports providing guidance on how to identify, conceptualize, and design natural infrastructure solutions for riverine and coastal systems. It has been produced by the US Army Corps of Engineers (USACE) Engineering With Nature® Program.

28 Jul 2025

Predicting Frozen Ground and Thaw Risk from Standard Land Model Output: Data, Algorithms, and GeoWATCH Implementation

Abstract: The Geospatial Weather Affected Terrain Conditions and Hazards (GeoWATCH) tool provides real-time mobility predictions at 30 m resolution on demand for any location on the globe. This tool combines dynamic weather data provided by the Air Force 557 Weather Wing (557WW) with static terrain data to downscale soil moisture from global and regional scales to resolutions better suited for terrain analysis applications. Frozen and thawing ground data layers were recently incorporated into the GeoWATCH framework to better support terrain assessment for Warfighter functions in cold regions. This report documents our approach for diagnosing the frozen and thawing ground data layers and provides examples. First, using data from controlled land-surface model simulations, we established simple curve-fitting formulas relating soil temperature to frozen water content. We then added the new formulas to the GeoWATCH code so that end users can generate frozen soil products on demand. Finally, GeoWATCH uses the resultant frozen soil product with a series of soil layers to determine the risk of actively thawing soil and springtime mud conditions. While the new overlays are not integrated into the GeoWATCH mobility diagnostic calculations, they provide insight into soil state conditions critical for operations and weather-based risk assessment in cold regions.

25 Jul 2025

Brandon Road Lock and Dam, Des Plaines River: Navigation Approach Physical Model

Abstract: This physical model study of the Brandon Road Lock and Dam was conducted to evaluate the navigation conditions associated with the implementation of two proposed engineered channels and associated features in the downstream approach channel. A 1:100 Froude scale physical model was constructed to evaluate the navigation conditions for tows entering and exiting the lower approach. Features included in the scaled model include the lock, the gated spillway, roughly 2 mi of the Des Plaines River and surrounding topography, and two NRG Energy generating stations. Data were collected to evaluate tow tracks and current direction and velocity information. Videos and rough estimations were also collected to gain an understanding of the water that displaces upstream when a downbound tow transits through the engineered channels.

18 Jul 2025

Antecedent Precipitation Tool (APT) Version 3.0 : Technical and User Guide

Abstract: This document provides an overview of the technical components of the Antecedent Precipitation Tool (APT) and a user’s guide for the APT. The APT is an automation tool that the US Army Corps of Engineers (USACE) developed to facilitate the comparison of antecedent or recent precipitation conditions for a given location to the range of normal precipitation conditions that occurred during the preceding 30 yr.* In addition to providing a standardized methodology to evaluate normal precipitation conditions (precipitation normalcy), the APT queries additional datasets to compute drought condition indices and the approximate dates of the wet and dry seasons for a given location. The latest update to the APT builds upon the precipitation normalcy methodology by generating streamflow normalcy for the United States Geological Survey (USGS) gage and National Oceanic and Atmospheric Administration (NOAA) National Water Model (NWM) simulation results. The update also expands the APT’s analysis domain to include Alaska, Hawaii, Puerto Rico, and the US Virgin Islands.

17 Jul 2025

Overview of the Coastal STORM (CSTORM) Model Development for the Swan Island Restoration Study

Abstract: This document summarizes the numerical model development and validation approach used to simulate the winds, waves, and water levels observed at Swan Island during two prominent historical storm events in the region: Hurricane Sandy and Hurricane Isabel. Using the Coastal STORM (CSTORM) Modeling System, which couples the Advanced Circulation (ADCIRC) and Steady-State Spectral WAVE (STWAVE) models, the North Atlantic Coast Comprehensive Study mesh and grid were refined in the area surrounding Swan Island. The nodal attributes of the ADCIRC mesh in the area surrounding Swan Island were updated to reflect the location of submerged aquatic vegetation around the island. ADCIRC-modeled water levels were in acceptable agreement with observed water levels during both storms, though peak water levels were slightly underpredicted. Similarly, STWAVE captured the phase and trends of the significant wave heights during the storm, while slightly underpredicting both significant wave height and peak period. The validated model will be used to investigate the effect of the restoration of Swan Island on the surrounding area. The results will help to develop guidelines for best practices in island restoration within the Chesapeake Bay and beyond.

17 Jul 2025

The Profile Feature Extraction Toolbox User’s Guide

Abstract: The Profile Feature Extraction Toolbox was created by the Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX) to extract profile features from high-resolution topobathymetric lidar datasets using a transect methodology. This user’s guide details the JALBTCX Toolbox framework, the Profile Feature Extraction Toolbox, and then walks the user through each step within the toolbox to be used alongside example data from Golovin, Alaska. Best practices and example data figures are included for additional assistance to new users. For the full documentation of the JALBTCX Toolbox framework, please see https://cirpwiki.info/wiki/JALBTCX.

3 Jul 2025

Inner Harbor Navigation Canal Lock Replacement Study: Hydrodynamic Modeling and Ship Simulation

Abstract: The Inner Harbor Navigation Canal (IHNC) Lock connects the Mississippi River to the Gulf Intracoastal Waterway, surrounded by developed areas in New Orleans, Louisiana. Tow transit times through the current IHNC lock take up to 20 hours. The US Army Corps of Engineers, New Orleans District, has proposed constructing a new lock to reduce tow transit times significantly. However, the new lock will have potential effects on vehicle traffic patterns due to the three bridges across IHNC. To address potential navigation issues, hydrodynamic modeling and ship simulations of the study area were conducted for the three phases of the project: new lock construction, present lock deconstruction, and proposed new lock design. The hydrodynamic model was developed and validated to present conditions, simulating various water levels across the lock structure to provide water levels and currents for ship simulation. The ship simulation was used to record transit times to determine impacts of the waterborne vessel traffic on vehicular traffic due to bridge raising and lowering, as well as navigability of the bypass channels associated with lock construction and existing lock deconstruction. Elicitation from the towing industry was used to inform final design of the new IHNC lock and bypass channels.

16 Jun 2025

Estuarine Dams and Weirs: Global Analysis and Synthesis

Abstract: Estuarine dams and weirs are constructed in estuaries for blocking the salt intrusion, securing freshwater, and stabilizing upstream water levels. While they can provide many social benefits, they also alter physical and sedimentary processes. To address this, we perform and extensive remote sensing and literature analysis. Remote sensing was conducted based on a global river database of 1531 rivers representing the largest rivers cumulatively draining 85 % of the landmass discharging into the global ocean. It was found that 9.7 % of global estuaries and deltas are currently affected by estuarine dams or weirs acting as the upstream limit of salt, tide, or storm surge intrusion. Most estuarine dams and weirs are located at x = 0–100 km inland from the mouth and their discharge intervals can be continuous. They are found most in river mouths which are wave-dominated followed by tide-dominated and then river-dominated. They can cause significant changes to the quantity and timing of freshwater discharge, tides, stratification, turbidity, sedimentation, oxygen conditions, phytoplankton blooms, and fish migration. We propose a conceptual model for physical and geomorphological change in mixed wave- and river-dominated and tide-dominated estuaries with estuarine dams.

16 Jun 2025

Enhancing Resilience: Integrating Future Flood Modeling and Socio-Economic Analysis in the Face of Climate Change Impacts

Abstract: As climate change intensifies, floods will become more severe in some areas with geographic variation, necessitating governments implementing systems providing information for climate adaptation. We aimed to develop a methodology identifying areas at an increased risk. In this study, 100-year recurrence interval flood extents and depths were estimated using an ensemble of six independent Coupled Model Intercomparison Project Phase 6 climate models for a past and future period under the highest-emissions climate scenario. The flood inundation results were related to social vulnerability for two study areas in the Mississippi River Basin. To identify at-risk areas, the relationship between the spatial distribution of flood depths and vulnerability was assessed. Finally, an analysis of current and future damages on infrastructure from flooding on residential housing to determine whether damages correlated with higher vulnerability areas. Results show flood extents and depths are increasing in the future, ranging from an increase of 6 to 76 km2 in extent. A statistically significant relationship between spatial clusters of flooding and of vulnerability was found. Overall, a framework was established to holistically understand the hydrologic and socioeconomic impacts of climate change, and a methodology was developed for allocating resources at the local scale.

13 Jun 2025

User Guidelines on Catchment Post-Wildfire Hydrological Modeling

Abstract: Wildfires significantly alter watershed hydrology by increasing runoff due to reduced infiltration from soil-water repellency. To predict long-term wildfire impacts, a coupled framework was developed to simulate postfire changes in soil hydraulic properties, infiltration, and hydrological response. This framework integrates Wildfire-Induced Soil Hydraulic (WISH) Factors with a Soil-Moisture Threshold (SMT) formulation in the Green and Ampt infiltration model, representing reduced infiltration due to water repellency. Postfire inputs, including burn severity, soil type, and land use, are formatted for the Gridded Surface Subsurface Hydrologic Analysis (GSSHA) model to ensure realistic hydrological simulations. The approach was applied to the 41.7 km² Upper Arroyo Seco watershed in northeast Los Angeles County, where 95% of the area was burned during the August 2009 Station Fire. Hydrological simulations effectively captured increased water repellency and excess runoff following postfire rainfall, demonstrating the model’s ability to represent wildfire-induced watershed changes and improve postfire hydrological assessments.