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  • Notice of Availability of the Interim Draft of the National Ordinary High Water Mark Field Delineation Manual for Rivers and Streams

    The U.S. Army Corps of Engineers (USACE) and the U.S. Environmental Protection Agency (EPA) jointly announce the availability of the Interim Draft of the National Ordinary High Water Mark Field Delineation Manual for Rivers and Streams (National OHWM Manual) and are soliciting public comments on this Interim Draft.

  • SWF hosts Emergency Management Public Law 84-99 Outreach Session

    Maj. Joshua Haynes, deputy commander, Fort Worth District, welcomes regional stakeholders to an outreach session to discuss recent changes to Public Law 84-99.

  • USACE announces seasonal closure of the Dewey Short Visitor Center at Table Rock Lake

    The Dewey Short Visitor Center will close for the season Dec.1 and will reopen March 1, 2023. The surrounding grounds, picnic facility and the 2.2- mile Lakeshore Trail to State Park Marina will remain open daily from 6 a.m. to 10 p.m.

  • Automation of Gridded HEC-HMS Model Development Using Python: Initial Condition Testing and Calibration Applications

    Abstract: The US Army Corps of Engineers’s (USACE) Hydrologic Engineering Center-Hydrologic Modeling System (HEC-HMS) rainfall-runoff model is widely used within the research community to develop both event-based and continuous rainfall-runoff models. The soil moisture accounting (SMA) algorithm is commonly used for long-term simulations. Depending on the final model setup, 12 to 18 parameters are needed to characterize the modeled watershed’s canopy, surface, soil, and routing processes, all of which are potential calibration parameters. HEC-HMS includes optimization tools to facilitate model calibration, but only initial conditions (ICs) can be calibrated when using the gridded SMA algorithm. Calibrating a continuous SMA HEC-HMS model is an iterative process that can require hundreds of simulations, a time intensive process requiring automation. HEC-HMS is written in Java and is predominantly run through a graphical user interface (GUI). As such, conducting a long-term gridded SMA calibration is infeasible using the GUI. USACE Construction Engineering Research Laboratory (CERL) has written a workflow that utilizes the existing Jython application programming interface (API) to batch run HEC-HMS simulations with Python. The workflow allows for gridded SMA HEC-HMS model sensitivity and calibration analyses to be conducted in a timely manner.

  • Game-changing refueling operations for JBLM helicopters

    A new $25.1 million airfield refueling facility became operational on Gray Army Airfield at Joint Base Lewis-McChord following a ribbon-cutting ceremony Nov. 17. The new facility can refuel Army helicopters on three, hot-fueling pads without the helicopters having to shut down.

  • Partners to deliver an aquatic ecosystem restoration project at Harlan County Lake, Nebraska

    The delivery of an aquatic ecosystem restoration project at Harlan County Lake, Nebraska, was initiated upon the request of Nebraska Game and Parks Commission. The partnership project is authorized under Section 1135 of the Water Resources Development Act of 1986 and is expected to be an investment of approximately $10 million. The U.S. Army Corps of Engineers, Kansas City District has been working with the agencies over the past several years to determine feasibility and develop of a conceptual design for this project. The agencies signed an agreement starting the detailed design stage of the project in May 2022.

  • USACE seeking public input on proposed updates to Public Law 84-99

    The U. S. Army Corps of Engineers is updating part of the Federal Regulation outlining how USACE implements its emergency authority provided in Public Law 84-99 for disaster preparedness, response, and recovery. The regulation was last revised in 2003. Since that time, there have been amendments to Public Law 84-99 through multiple Water Resource Development Acts passed by Congress. Additionally, USACE programs have evolved to implement lessons learned from events over the last 20 years. USACE will update the federal regulation to reflect these changes.

  • Risk-Based Prioritization of Operational Condition Assessments: Methodology and Case Study Results

    Abstract: USACE operates, maintains, and manages more than $232 billion of the Nation’s water resource infrastructure. USACE uses the Operational Condition Assessment (OCA) to allocate limited resources to assess condition of this infrastructure in efforts to minimize risks associated with performance degradation. The analysis of risk associated with flood risk management (FRM) assets includes consideration of how each asset contributes to its associated FRM watershed system, understanding the consequences of the asset’s performance degradation, and a determination of the likelihood that the asset will perform as expected given the current OCA condition ratings of critical components. This research demonstrates a proof-of-concept application of a scalable methodology to model the probability of a dam performing as expected given the state of its gates and their components. The team combines this likelihood of degradation with consequences generated by the application of designed simulation experiments with hydrological models to develop a risk measure. The resulting risk scores serve as an input for a mixed-integer optimization program that outputs the optimal set of components to conduct OCAs on to minimize risk in the watershed. This report documents the results of the application of this methodology to two case studies.

  • Numerical Analysis of Dike Effects on the Mississippi River Using a Two-Dimensional Adaptive Hydraulics Model (AdH)

    Abstract: This report describes the hydraulic effects of dikes on water surface elevation (WSE) and velocities in the Mississippi River near Vicksburg, MS, from Interstate 20 to Highway 80 using a previously calibrated 2D Adaptive Hydraulics numerical model. Dike heights and their associated hydraulic roughness values were varied to quantify the overall effects of adjustments to dike fields. Steady flows characterized as low, medium, and high conditions were simulated. The WSE and velocity difference plots were generated to illustrate the hydraulic effects on the river under all scenarios discussed above. Overall, the dike adjustments had negligible impacts on WSEs and showed minimal effects on velocities on a system wide scale.

  • National Ordinary High Water Mark Field Delineation Manual for Rivers and Streams : Interim Version

    Abstract: The ordinary high water mark (OHWM) defines the lateral extent of nontidal aquatic features in the absence of adjacent wetlands in the United States. The federal regulatory definition of the OHWM, 33 CFR 328.3(c)(7), states the OHWM is “that line on the shore established by the fluctuations of water and indicated by physical characteristics such as [a] clear, natural line impressed on the bank, shelving, changes in the character of soil, destruction of terrestrial vegetation, the presence of litter and debris, or other appropriate means that consider the characteristics of the surrounding areas.” This is the first manual to present a methodology for nationwide identification and delineation of the OHWM. A two-page data sheet and field procedure outline a weight-of-evidence (WoE) methodology to organize and evaluate observations at stream sites. This manual presents a consistent, science-based method for delineating the OHWM in streams. It also describes regional differences and challenges in identifying the OHWM at sites disturbed by human-induced or natural changes and illustrates how to use remote data to structure field inquiries and interpret field evidence using the principles of fluvial science. The manual demonstrates that, in many landscape settings, the OHWM may be located near the bankfull elevation.