• 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.
  • 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.
  • Evaluation of Tekcrete Fast for Airfield Pavement Repairs

    Abstract: Tekcrete Fast is a deployable, high-strength cementitious product with rapid bonding force that was initially developed to provide stability for structures damaged by seismic activity and explosives. The product was evaluated by researchers at the US Army Engineer Research and Development Center for its ability to execute necessary force projection and resilient infrastructure repairs for the US military without major negative impacts to the mission. Full-scale testing of the rapidly emplaced calcium-sulfoaluminate (CSA) concrete product was completed to identify the sustainability and strength of the material with military aircraft traffic. The CSA concrete mixture was designed for dry-mix shotcrete applications and adapted to be placed conventionally (cast-in-place) using a portable skid steer concrete mixer. This report presents a technical evaluation of the field performance of full-depth concrete repairs conducted using the cast-in-place Tekcrete Fast material in a portable concrete mixer. Passes-to-failure rates for each repair were determined using an F-15E load cart. Results indicated that Tekcrete Fast meets the military’s criteria for being an expedient pavement repair solution.
  • Engineering Readiness for the Indo-Pacific: The 34th Forward Engineer Support Team – Advance Deployment & Certification Training Exercise

    The 34th Forward Engineer Support Team - Advance (FEST-A), from the U.S. Army Corps of Engineers’ (USACE) Seattle District successfully conducted a Certification Exercise (CERTEX), used to validate deployment readiness for engineering support across the U.S. Indo-Pacific Command (USINDOPACOM).
  • Development of Innovative Cyanophage-Based Biotechnology for Harmful Cyanobacterial Blooms Mitigation: Interim Progress Report

    Abstract: Freshwater harmful cyanobacteria blooms (HCBs) are caused by toxin-producing cyanobacteria. Current efforts to prevent and mitigate HCBs include physical and chemical treatments, as well as manipulating the nutrient input and biological ecosystem of impacted water bodies. However, the development of remediation technologies lags behind the increasing frequency, prevalence, and severity of HCBs and their associated adverse health effects and socioeconomic losses. It is difficult to control the side effects of these remediation technologies due to their interactions with nontarget species, including microbes, plants, and animals. This project proposed the use of cyanophages, an abundant natural resource, to control HCBs in a target-specific manner. Here, the results of Year 1 of this effort are reported. Environmental field samples were collected, processed, and characterized morphologically and molecularly. Assays were refined for isolating and characterizing lytic environmental cyanophages. Cryopreservation methods were tested on pure cyanobacteria cultures, while well-characterized cyanophages were used to verify methods to retain infectivity for over 1 year. Methods to induce lysogenic phages to enter their lytic cycle were also explored. The goal was to develop a novel cyanophage-based biotechnology for HCBs mitigation by turning field-collected cyanophages into genetically modified (GM) or non-GM biocontrol agents to disrupt HCBs.
  • Fort Peck Interpretive Center celebrates 20 years

    The U.S. Army Corps of Engineers is celebrating 20 years since opening the Fort Peck Dam Interpretive Center and Museum in Fort Peck, Montana on Saturday, June 21, 2025. In addition, the Montana Dinosaur Trail also turns 20 this year. The Interpretive Center will be open June 21 from 9 a.m. to 4 p.m.
  • Helping hands: ERDC employees volunteer for LA wildfire recovery

    Each year, the U.S. Army Corps of Engineers (USACE) deploys hundreds of trained personnel and resources across the United States and its territories to aid in disaster relief efforts. In the aftermath of hurricanes, fires, floods or infrastructure crises, USACE emergency operations is responsible for coordinating and executing several missions in post-disaster environments. As part of this response, ERDC employees volunteer their time and expertise, making a tangible impact in communities affected by disaster.
  • USACE Vicksburg District recognizes employee excellence at annual Corps of Engineers Awards Day

    VICKSBURG, Miss. – The U.S. Army Corps of Engineers (USACE) Vicksburg District recognized dedicated personnel at the annual Corps of Engineers Day Awards Ceremony at the District headquarters on Thursday, June 12, 2025.
  • Army Corps of Engineers announces proposal to renew and revise nationwide permits

    The U.S. Army Corps of Engineers (USACE) announced today that it has prepared its proposal to renew and revise 56 of 57 existing nationwide permits for work in wetlands and other waters that are regulated by Section 404 of the Clean Water Act and/or Section 10 of the Rivers and Harbors Act of 1899. USACE will propose not to reissue one nationwide permit authorizing activities associated with finfish mariculture. USACE will also propose to issue one new nationwide permit that pertains to authorizing activities to facilitate fish passage. A prepublication copy of the proposal has been posted on the USACE website at: https://www.usace.army.mil/Missions/Civil-Works/Regulatory-Program-and-Permits/National-Notices-and-Program-Initiatives/
  • Army Corps of Engineers announces proposal to renew and revise nationwide permits

    The U.S. Army Corps of Engineers (USACE) announced today that it has prepared its proposal to renew and revise 56 of 57 existing nationwide permits for work in wetlands and other waters that are regulated by Section 404 of the Clean Water Act and/or Section 10 of the Rivers and Harbors Act of 1899. USACE will propose not to reissue one nationwide permit authorizing activities associated with finfish mariculture.