15 Oct 2025

An Investigation into the Correlation Between Selected Coastal Protection Indices and Percent Residual Dune and Berm Volumes Following Coastal Storms

Abstract: Morphometric indices describe the dimensions of a dune and berm profile and can serve as relative metrics of coastal protection. However, coastal vulnerability to storm damage also depends on storm, wave, sediment, and offshore characteristics. Recently, more elaborate non-morphometric indices have been proposed in an effort to account for these other factors. This study compares the correlation between these morphometric and non-morphometric indices and one measure of coastal protection, the ability of a dune and berm profile to resist storm-induced changes in volume. This study uses a numerical-simulation approach rather than an empirical approach because a sufficiently comprehensive set of observational data does not exist. A randomized sample of dune and berm profiles were generated at eight coastal locations. Using the cross-shore numerical model (CSHORE), storm-induced changes in dune and berm volume were simulated for storms of low to moderate severity. The correlation between the various prestorm indices and the percentage of prestorm dune and berm volume remaining after the storm was calculated at each location. Results show that no single index always exhibits a higher correlation with percent dune and berm volume remaining. However, some indices were far more likely than others to produce higher correlations.

1 Oct 2025

Numerical Storm Surge Modeling and Probabilistic Analysis for Evaluating Proposed New Jersey Back Bays Inlet Closures

Abstract: The US Army Corps of Engineers, Philadelphia District, and the New Jersey Department of Environmental Protection are currently engaged in the New Jersey Back Bays (NJBB) Coastal Storm Risk Management Feasibility Study. The US Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory, conducted a numerical hydrodynamic modeling and probabilistic hazard analysis study to evaluate the effectiveness of storm surge barriers in reducing water levels in the NJBB. The numerical modeling study included the simulation of water levels and a comparison of water surface elevations and corresponding annual exceedance frequency between existing conditions and six final project alternatives. Results from the hydrodynamic simulations and probabilistic analysis are presented herein.

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.

3 Sep 2025

Hydrodynamics in the Morganza Floodway and Atchafalaya Basin, Report 5: Phase 5

Abstract: The Morganza Floodway and Atchafalaya Basin, located in Louisiana west of the Mississippi River, were evaluated using a 2D Adaptive Hydraulics model. Prior to this study, Phase 1 and 2 model studies showed that the Morganza Floodway may not be able to pass the Project Design Flood discharge of 600,000 cubic feet per second due to levee overtopping. Phase 3 and 4 model studies help to further the understanding of how flood waters propagate throughout the floodway as well examined alternatives to increase the discharge capacity of the floodway. Phase 5 furthered the work completed in Phases 3 and 4 by exploring more alternatives to aid the Morganza Floodway in passing the Project Design Flood.

3 Sep 2025

Hydrodynamics in the Morganza Floodway and Atchafalaya Basin, Report 4: Phase 4

Abstract: The Morganza Floodway and Atchafalaya Basin, located in Louisiana, west of the Mississippi River, were evaluated using a two-dimensional Adaptive Hydraulics model. Prior to this study, Phase 1 and 2 model studies showed that the Morganza Floodway may not be able to pass the Project Design Flood discharge of 600,000 cfs due to levee overtopping. A Phase 3 model study helped to further the understanding of the effects of trees and vegetation on the flow capacity of the floodway. In Phase 4 of this study, changes in elevations through means of excavation as well as the cutting of rights-of-way (ROW) were examined to determine their effects on flow conveyance in the floodway.

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.

5 Jun 2025

Incorporating Natural and Nature-Based Features in an Urban California Creek Through Application of Engineering With Nature® Principles

Purpose: Since its launch in 2021, the Engineering With Nature® (EWN®) program has funded research focused in a variety of environments, particularly along marine and freshwater coasts and fluvial (riverine) systems. Until recently, there has been less focus on applying EWN principles in urban landscapes and watersheds to help manage flood risk, a main civil works mission of the US Army Corps of Engineers (USACE). Natural hazard challenges, including intense rainfall events, are contributing to flooding and prompting the need for more sustainable infrastructure to reduce flood risks in urban areas. This is especially relevant when such nature-based solutions (NBS) are desired by stakeholders who stand to benefit from the project. This technical note documents a USACE Chicago District (LRC) project that supports USACE Los Angeles District (SPL) to incorporate EWN principles in an urban ephemeral creek to reduce flood risk while providing other environmental, social, and economic benefits.

13 May 2025

Development and Testing of the FRAME Tool on a 200-Mile Reach of the Lower Mississippi River

Abstract: Understanding the likely long-term evolution of the Lower Mississippi River (LMR) is a challenging mission for the US Army Corps of Engineers (USACE) that remains difficult for conventional river engineering models. A new type of model is currently in development, tasked with revealing uncertainty-bounded trends in sediment transport and channel morphology over annual, decadal, and centennial timescales. The Future River Analysis and Management Evaluation (FRAME) tool is being designed with river managers and planners in mind to provide exploratory insights into plausible river futures and their potential impacts. A unique attribute of the tool is its hybrid interfacing of traditional one-dimensional hydraulic and sediment transport modeling with geomorphic rules for characterizing the morphological response. This report documents the development of a FRAME test-bed model for a 200-mile reach of the Mississippi River upstream of Vicksburg, Mississippi. This testbed allowed development and testing of the prototype FRAME tool in a data-rich environment. This work identified proposed future developments to provide river managers and planners with a fully functional tool for delivering insights on long-term morphological response in river channels across a variety of spatial and temporal scales.

3 Apr 2025

Ohio Creek Urban Coastal Storm Risk Management Project: An Application of Engineering With Nature® Principles in Practice

Purpose: The Engineering With Nature® (EWN®) program within the US Army Corps of Engineers (USACE) funds research projects occurring in a myriad of environments, including in marine coasts, freshwater coasts, and fluvial (riverine) systems. Yet there have been fewer projects documented where EWN principles have been applied in urban landscapes, particularly to manage flood risk, a main civil works mission of the USACE. Natural hazards including increased flashiness associated with intense rainfall events have prompted the need for more sustainable infrastructure solutions that reduce flood risks in urban areas, especially when such solutions desired by stakeholders are nature-based solutions. This technical note documents a flood risk management project in Norfolk, Virginia, that incorporates EWN principles in a tidal estuary environment that not only reduces flood risk, but also provides numerous other environmental, social, and economic benefits.

21 Jan 2025

Engineering With Nature: Natural Infrastructure for Mission Readiness at U.S. Navy and Marine Corps Installations

Abstract: This book illustrates some of the current challenges and hazards experienced by military installations, and the content highlights activities at eight U.S. Navy and Marine Corps military installations to achieve increased resilience through natural infrastructure.