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  • Physical Modeling of Filling and Emptying (F&E) Systems of Proposed 1,200 ft Chambers at Locks 22 and 25: Hydraulic Model Investigation

    Abstract: The US Army Corps of Engineers (USACE) is considering navigation improvements for several projects to meet predicted increases in tow traffic at the Lock and Dam 22 and Lock and Dam 25 sites in the Mississippi river. Some of these improvements include the addition or replacement of the navigation lock at the site. The following document contains the laboratory model investigations of the lock filling and emptying (F&E) system for additions at the sites. This report provides the results of research testing under the Navigation and Ecosystem Sustainability Program (NESP). The design guidance includes culvert geometry, port size, location, and spacing. Guidance for the lock chamber performance, based on acceptable filling and emptying operations is also included. The results show that the original design is a feasible design based on the hydraulic performance of the system as a result of the experimental tests. Further discussions with the St. Louis District (CEMVS) arrived at a new culvert to port transition design that was more in line with the existing geometry at Lock and Dam 25. The new design and port spacing configuration were agreed by CEMVS and ERDC to not have significant impact on hawser forces or the overall chamber performance.

  • Minneapolis Lock and Dam 1 open house canceled

    The U.S. Army Corps of Engineers, St. Paul District, announced today that the Lock and Dam 1 open house is canceled.

  • Gravel Investigations Informing Resource Management Within the Lower Mississippi River

    Abstract: This report integrates available information about gravel deposits within the Lower Mississippi River (LMR) from previous studies coupled with new analysis to identify reoccurring observed gravel locations. This study also summarizes spatial and temporal trends of bed material sediment characteristics, focusing primarily on gravel. Moreover, selected data sets from previous studies, and field and aerial observations have been added to a geographic information system (GIS) database housed in ArcPro to illustrate observed gravel locations. Last, a literature review documenting the ecological importance of gravel bars to riverine fauna and a brief discussion of potential technologies to support conservation efforts are included. Major findings summarized herein are (1) the presence of gravel deposits tend to decrease in a downstream direction along the LMR; (2) qualitative analyses of aerial videos suggest that gravel-predominant bars are more common between River Miles 953 and 681; (3) past investigations have documented gravel sizes at rivers bars ranging from pebbles to boulders; (4) the gravel content in LMR bed material samples has decreased since 1932; and (5) more detailed surveys are needed to better delineate the spatial extents and depth of gravel bars and identify suitable technology to detect potential buried gravel.

  • 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.

  • U.S. Army Corps of Engineers Seeks Public Input for Mississippi & Illinois River Habitat Restoration

    The U.S. Army Corps of Engineers, in collaboration with state and federal partners, announces the launch of the Mississippi & Illinois River Experience Tool, a new initiative to gather public input to inform future restoration efforts under the Navigation and Ecosystem Sustainability Program (NESP).

  • Arkansas City to Vicksburg Adaptive Hydraulics Model

    PURPOSE: The purpose of this study is to develop and validate a 2D, depth-averaged hydrodynamic model of the Mississippi River from Vicksburg, Mississippi, to Arkansas City, Arkansas, to accurately replicate low-flow conditions. The model will be used to support an ongoing effort for the development of a low-water forecast model to aid navigational resilience.

  • Geology, Geomorphology, and River Engineering in the Memphis-to-Rosedale Reach, Lower Mississippi River

    Abstract: This study examines the geology and geomorphology of the Mississippi River between Memphis, Tennessee, and Rosedale, Mississippi, with a focus on the Tertiary (65 to 2 million years) surface and how the present-day river has impacted this surface. Previous mapping efforts involving the Tertiary surface by the US Army Corps of Engineers are reviewed. Relevant maps are included as plates herein to facilitate wider dissemination. Today’s channel has deepened through time due to river engineering, which includes oxbow cutoffs and hardening of river banks with revetment and training dikes to prevent uncontrolled bank caving and channel migration. The course of the river was fixed in place by 1962. The thalweg of the river intersects the Tertiary surface at Helena, Arkansas, at the Hardin oxbow cutoff, and near the vicinity of Memphis, Tennessee. At these three locations, the Tertiary surface occurs at shallow elevations and in close proximity to where Tertiary sediments outcrop. A deeply buried alluvial valley is present in the Tertiary surface. Erosion of Jackson Group sediments in this valley exposes the underlying Claiborne Group sediments. Jackson and Sunflower oxbow cutoffs occur in the deepest parts of the alluvial fill.

  • 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.

  • 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.

  • Evaluating Transport of Stockpiled Mississippi River System Sand for Beach Nourishment and Other Uses

    The US Army Corps of Engineers (USACE), Rock Island and St. Paul Districts, maintain 876 miles of shallow-draft navigation channels, dredging approximately 2 million cubic yards of clean, fine- to medium-grained sands from these waterways annually. Due to system constraints and certain state regulatory policies, most of this dredged material (DM) is placed in upland and island facilities. As these dredge placement areas fill with sediment, the districts need to remove sediment to create additional storage or seek new land acquisition. While a significant amount of this DM is being locally used beneficially, the current uses are opportunity driven and dictated by proximity. As such, the districts continue to seek alternative beneficial use practices. One major limiting factor to increased beneficial use is the cost of material transport. Per the Federal Standard, USACE will use the least costly DM placement alternatives that are consistent with sound engineering practices and meet federal environmental requirements. Transport beyond traditional placement sites typically costs much more. The analysis described in this report reviews nontraditional transportation modes and routes to match distant needs with river sediment.