12 Jan 2024

Levees and Dams at Fort Riley, Kansas, and the Response to the 1951 Flood

Abstract: This project provides a historic context and inventory for the levees and dams constructed at Fort Riley, Kansas. The purpose of this historic con-text and inventory is to determine the levees and dams’ eligibility for listing in the National Register of Historic Places (NRHP). Determinations of eligibility to the NRHP are then made based on the significance of the levees and dams and the degree to which they retain their integrity for conveying that significance. The authors inventoried and evaluated three levees and two lake dams on the installation. Based on the historic context and inventory, researchers for this project have determined that none of the levees and dams are eligible for the inclusion in the NRHP nor was there enough evidence for a noncontiguous historic district at Fort Riley.

16 Jun 2023

Evaluation of a Permeable Dam as an Erosion Control Structure on Coca River, Ecuador

Abstract: The effort performed here describes the process to evaluate the scour-protection performance of the proposed permeable dam. The US Engineer Research and Development Center, Coastal and Hydraulics Laboratory, built a 1:50 Froude scaled movable bed section model of the permeable dam structure and tested in a specialized flume that simulates regressive erosion propagation. Profiles were collected at various times to track the progression of the scour. Tests evaluated variations of the proposed structure, which included tetrapods, riprap, bridge piers, and longitudinal piles. For the various proposed alternatives, a total of six tests were conducted. The collected profiles show the ability or inability of each alternative and its associated performance. From this analysis, untethered tetrapods could not effectively arrest the local scour around the structure. However, large rock along with invert control stopped the regressive erosion and held the upstream grade.

30 Nov 2022

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.

27 Jul 2022

Environmental Effects of Sediment Release from Dams: Conceptual Model and Literature Review for the Kansas River Basin

PURPOSE: Passing sediment from reservoirs to downstream channels is a potential solution to aging infrastructure and reservoir storage capacity loss, which is a pressing challenge nationwide. The US Army Corps of Engineers (USACE) sediment management actions at reservoirs such as flushing may drive ecological changes that may be beneficial or detrimental to downstream ecosystems. However, these potential effects are currently not well understood or documented. An exploratory study of the potential ecological effects of releasing sediment downstream from reservoirs is presented in this technical note (TN). We focus on Tuttle Creek Reservoir in Kansas and use fish species as indicators of ecological change. A literature review of Kansas fishes was conducted and three conceptual models illustrating potential benefits or negative effects of releasing sediment downstream of Tuttle Creek Reservoir was developed. Some fish species may benefit from sediment releases, while others may be negatively affected. Further research and tools are needed to develop a greater understanding of these effects.

29 Sep 2021

Backward Erosion Testing: Magnolia Levee

Abstract: Using a confined flume device, an experimental study investigated the critical horizontal gradient of soils obtained from a site identified as potentially vulnerable to backward erosion piping (BEP). Tests were conducted on glacial outwash material obtained from a sand and gravel quarry in the vicinity of Magnolia Levee in the community of Magnolia, OH. The two bulk samples collected from the quarry had similar grain-size distributions, grain roundness, and depositional environments as the foundation materials beneath the levee. Samples were prepared at various densities and subjected to gradual increases of flow in a wooden flume with an acrylic top until BEP was observed. The critical average horizontal gradient ranged from 0.21 to 0.30 for a bulk sample with a coefficient of uniformity of 1.6, while tests conducted on a bulk sample with a coefficient of uniformity of 2.5 yielded critical average horizontal gradients of 0.31 to 0.36. The critical average gradients measured during these tests compared favorably to values in the literature after applying adjustments according to Schmertmann’s method.

29 Jun 2021

Rough River Outlet Works Physical Model Study

Abstract: The US Army Corps of Engineers, Louisville District, requested the support and assistance of the US Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory (CHL), in the evaluation of the hydraulic performance of the replacement Outlet Works for Rough River Dam. To support the design effort, CHL constructed a 1:25.85 scale physical model. The proposed features of the model in the domain are the curved approach channel, intake structure, transition, curved conduit, stilling basin, concrete apron, and retreat channel. Tests performed to evaluate the hydraulic performance illuminated a few design concerns. To address these issues, several key design changes were made. These included the retreat channel slope, end sill design, and transition design.