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  • Is Mean Discharge Meaningless for Environmental Flow Management?

    PURPOSE: River ecosystems are highly dependent on and responsive to hydrologic variability over multiple time scales (e.g., hours, months, years). Fluctuating river flows present a key challenge to river managers, who must weigh competing demands for freshwater. Environmental flow recommendations and regulations seek to provide management targets balancing socio-economic outcomes with maintenance of ecological integrity. Often, flow management targets are based on average river conditions over temporal windows such as days, months, or years. Here, three case studies of hydrologic variability are presented at each time scale, which demonstrate the potential pitfalls of mean-based environmental flow criteria. Each case study shows that the intent of the environmental flow target is not met when hydrologic variability is considered. While mean discharge is inadequate as a single-minded flow management target, the consequences of mean flow prescriptions can be avoided in environmental flow recommendations. Based on these case studies, a temporal hierarchy of environmental flow thresholds is proposed (e.g., an instantaneous flow target coupled with daily and monthly averages), which would improve the efficacy of these regulations.

  • Ecological Model Development: Evaluation of System Quality

    PURPOSE: Ecological models are used throughout the US Army Corps of Engineers (USACE) to inform decisions related to ecosystem restoration, water operations, environmental impact assessment, environmental mitigation, and other topics. Ecological models are typically developed in phases of conceptualization, quantification, evaluation, application, and communication. Evaluation is a process for assessing the technical quality, reliability, and ecological basis of a model and includes techniques such as calibration, verification, validation, and review. In this technical note (TN), we describe an approach for evaluating system quality, which generally includes the computational integrity, numerical accuracy, and programming of a model or modeling system. Methods are presented for avoiding computational errors during development, detecting errors through model testing, and updating models based on review and use. A formal structure is proposed for model test plans and subsequently demonstrated for a hypothetical habitat suitability model. Overall, this TN provides ecological modeling practitioners with a rapid guide for evaluating system quality.

  • Army Corps updates water release schedule for Francis E. Walter Dam

    The U.S. Army Corps Engineers’ Philadelphia District updated the 2022 Francis E. Walter Dam recreation plan. The Army Corps updated the plan, which states whitewater and fisheries releases will be scheduled if enough water storage is accumulated in the reservoir. Currently, there is enough water storage to schedule fisheries enhancement releases through Sept. 30.

  • MKARNS Nav Notice SWL 22-49 Sailing Instruction NM 179

    MKARNS - Mariners are advised that until further notice, both upbound and downbound tows should run the green line in the NM 179 vicinity.

  • Gate openings, guidelines announced for 2022, 2023 Raystown Hunting Seasons

    The U.S. Army Corps of Engineers (USACE) at Raystown Lake announces the opening of the following access roads to accommodate upcoming hunting seasons.

  • A Day at Sepulveda Dam

    ENCINO, California --U.S. Army Corps of Engineers Los Angeles District Park Rangers patrol Sepulveda Dam Aug. 19 in Encino, California.

  • USACE, AGFC and other agencies host Labor Day safety media event

    The U.S. Army Corps of Engineers, Arkansas Game and Fish Commission and other local agency partners met at Murray Lock and Dam today for a water and recreation holiday safety media event.

  • Assistant Secretary of Army reviews Arizona civil works projects

    PHOENIX – Assistant Secretary of the Army for Civil Works Michael Connor led a team from the U.S. Army Corps of Engineers to review several civil works project sites Aug. 31 -Sept. 1 in northern and central Arizona.

  • Fall Closures and Events at Carlyle Lake

    CARLYLE LAKE – Fall is one of the best seasons to spend time around the campfire and there is still time to enjoy the campgrounds at Carlyle Lake. The Coles Creek Campground will be closing September 26. Boulder Campground closes October 11. Dam West Campground and the north and south loops of McNair Campgrounds will close October 31. The Dam East-McNair Spillway Loop Campground and Eldon Hazlet State Park Campground will continue to operate year-round. Reservations for USACE campsites can be made by calling the National Recreation Reservation Service at 1-877-444-6777 or online at www.recreation.gov. Sites are also available on a first-come, first-serve basis. Eldon Hazlet State Park reservations can be made online at camp.exploremoreil.com.

  • Standard Operating Procedures for Open-Air Solid Waste Burning in Contingency Locations

    Abstract: Service engineer doctrine and field manuals, such as Army Techniques Publication 3-34.40, Technical Manual 5-634, and Army Regulation 420-1, offer guidance on solid waste management but do not provide the level of detail and practical guidance for open-air burning of solid waste to reduce risk to the Warfighter. Studies have shown that there could be ill health effects to service members from exposure to toxins from open-air burning. Further practical guidance is necessary to ensure that if there are no other means available for solid waste disposal, the risks associated with open-air burning are minimized as much as possible during contingency operations. Commands have limited resources and reduced personnel available to study which open-air burning procedures are optimal based on readiness and mission requirements. Planning for efficiency and risk avoidance in open-air burning operations includes several facets (e.g., site planning, processing, and recordkeeping considerations). This special report provides operational guidance to minimize risk of open-air burning for the Warfighter and other joint service personnel, particularly when there is no other alternative to open-air burning, during initial phase operating a burn pit or for waste management planning to establish standard operating procedures.