30 Jul 2020

PUBLICATION NOTICE: Investigation of Shoaling in the Federal Navigation Channel, Waukegan Harbor, Illinois

Abstract: Persistent and excessive shoaling occurs in the Outer Harbor and Approach Channel of the Waukegan Harbor, Illinois. This report describes a numerical modeling study performed for the US Army Corps of Engineers, Chicago District, to evaluate the existing harbor and 11 structural alternatives for three crest elevations. This report provides details of numerical modeling study, analysis of field data, and estimates of shoaling. The focus of the study is the investigation of a variety of structural solutions intercepting and/or diverting sediments to reduce shoaling in the navigation channel. These include breakwaters, groins, spurs, and structural extensions with varying length and crest elevation connecting to the north beach and existing north breakwater. Estimates of both shoaling volume and height are developed with and without project using an integrated wave-flow-sediment transport numerical modeling approach. Quantitative reduction estimates are provided for each structural alternative investigated.

9 Jul 2020

PUBLICATION NOTICE: Hydrodynamics of a Recently Restored Coastal Wetland: Hamilton Wetlands, California

Abstract: Hamilton Wetlands is a recently restored tidally influenced basin located along the northwest coast of San Pablo Bay, California. Instruments to measure waves, currents, and wind were deployed for a period of up to 2 years shortly after tidal flow was re-introduced to the wetland to examine the sediment and hydrodynamic response. The results indicate that local re-suspension is relatively rare owing to the weak interior tidal currents and the limited fetch within the 3 km long basin. Asymmetries in the acoustic backscatter intensity combined with the much higher flow speeds measured at the entrance suggest a net import of fine sediment. The basin also experiences a distinct seasonal variation that likely contributes to sediment re-distribution. During the summer months, higher wind speeds correlate with turbidity suggesting local re-suspension of fines that are distributed by winds. Overall, the measurements suggest that the sediment dynamics in this shallow water system are controlled by two main factors: (1) net sediment import through the inlet entrance and (2) mixing of interior sediment through a combination of intermittent wind and wave stirring.

17 Jun 2020

PUBLICATION NOTICE: Sediment Sorting by Hopper Dredging and Pump-Out Operations: Conceptual Model and Literature Review

Abstract: Dredged sediment placed on beaches or nearshore environments is customarily evaluated for compatibility with the native beach sediment to avoid unintended impacts to economic, environmental, or recreational resources. Consequently, some state regulatory authorities establish limits upon the fine-grained content for sediment designated for placement on certain beaches and nearshore environments. Hopper dredging operations for beach and nearshore placement typically include periods of overflow, which is recognized to produce some degree of separation between the size fractions of the dredged sediment. The degree of separation and the controlling factors of separation are presently poorly known and are the subject of this research. This report provides a conceptual model of the hopper dredging and placement processes, including the relevant processes associated with hopper dredge-associated sediment dynamics, generation and transport of the overflow sediment plume, and sediment winnowing at the beach outflow. Prior research is described, and knowledge gaps are identified. Finally, a research plan to validate prior research and to address knowledge gaps is presented. An annotated bibliography of relevant literature is given in an appendix. Documentation of the planned research presented herein will appear in future publications associated with this study.

10 Jun 2020

PUBLICATION NOTICE: Nearshore Placement Workshop 2019: Sediment Nourishment of the Nearshore Environment

Abstract: The Coastal Inlets Research Program and the Regional Sediment Management Program co-sponsored the 2019 Nearshore Placement Workshop. Thirty-four participants from the US Army Engineer Research and Development Center (ERDC) and numerous districts met in Vicksburg on January 29–30, 2019, as a part of the workshop. This workshop was convened to facilitate discussions on concerns districts face regarding nearshore placements from resource agencies and stakeholders, challenges to placing sediment in the nearshore, and future research needs. The workshop included ERDC presentations on the state of the science regarding nearshore placements; specific implementations of nearshore placements within various US Army Corps of Engineers districts; break-out-style discussions on nearshore placement challenges and potential paths forward; and group discussions on metrics for success, quantification of benefits, Statements of Need (SON), and research priorities. A few of the major recurring themes throughout the workshop were the importance of monitoring, concerns over the fate of fine-grained sediment, and difficulties conveying the benefits of nearshore placements to a wide range of audiences. The workshop culminated in a discussion of possible SON to be put forth to the ERDC research and development community. This special report describes the discussions and outcomes of the 2019 Nearshore Placement Workshop.

30 Apr 2020

PUBLICATION NOTICE: Seamless Integration of Lidar-Derived Volumes and Geomorphic Features into the Sediment Budget Analysis System

Abstract: This Regional Sediment Management Technical Note provides a workflow and case study documenting the process to integrate lidar-derived volume changes and changes quantified from geomorphic features into the Sediment Budget Analysis System. Sediment budgets provide an understanding of a region’s sediment sources, project needs, processes, data gaps, engineering actions, and ecological considerations. Elevation data from profiles or lidar, sediment characteristics, dredging and placement information, along with other coastal datasets, are used to understand sediment pathways and develop sediment budgets for a region. Workflows and tools have been updated or modified to integrate sediment budget tools, volume change tools, and remote sensing data for the creation of comprehensive regional sediment budgets. 

30 Apr 2020

PUBLICATION NOTICE: Geochemical Fingerprinting of Sediment Sources Associated with Deposition in the Calcasieu Ship Channel

Abstract: This Regional Sediment Management Technical Note (RSM-TN) demonstrates how geochemical fingerprinting techniques were used to distinguish probable sediment sources to the Calcasieu Ship Channel (CSC). These methods were applied to sediment samples collected from suspected source areas identified in past sediment budget studies. The techniques can be used by managers and stakeholders to make more informed decisions on best practices for managing sediment and mitigating sediment deposition within the channel.

29 Apr 2020

PUBLICATION NOTICE: Application of Chirp Acoustic Sub-Bottom Data in Riverine Environments: Identification of Underlying Rocky Hazards at Cape Girardeau, Missouri, and Thebes, Illinois

NOTE: A revised version of the report MRG&P Report No. 31 has been published. While the link below remains valid, the PDF attached to the record is new. It is now 47 pages instead of 45 pages after the changes made. Please update your records as needed.

22 Apr 2020

PUBLICATION NOTICE: Analysis of Nearshore Placement of Sediments at Ogden Dunes, Indiana

ABSTRACT: The harbor structures/shoreline armoring on the southern Lake Michigan shoreline interrupt sand migration. Ogden Dunes, Indiana, and the nearby Indiana Dunes National Lakeshore observed shoreline erosion due to engineered structures associated with Burns Waterway Harbor (east of Ogden Dunes) impeding natural east-to-west sediment migration. To remedy this, USACE placed over 450,000 cubic meters (m3) of dredged material post-2006 in the nearshore of Ogden Dunes. However, the effectiveness of nearshore placements for shoreline protection and littoral nourishment is not fully established. To improve nearshore placement effectiveness, USACE monitored the June/July 2016 placement and subsequent movement of 107,000 m3 of dredged material in the nearshore region at Ogden Dunes. This involved an extensive monitoring scheme (three bathymetry surveys, and two acoustic Doppler current profiler deployments), a Coastal Modeling System (CMS) numerical model of the changes following placement, and a prediction of sediment transport direction using the Sediment Mobility Tool (SMT). The SMT-predicted sediment migration direction was compared to observations. Observations indicated that between 10/11/2016 and 11/15/2016 the centroid of the sediment above the pre-placement survey moved 17 m onshore. These observations agreed with SMT predictions — onshore migration under storm and typical wave conditions. CMS accurately reproduced the hydrodynamic features.

20 Apr 2020

PUBLICATION NOTICE: Application of Chirp Acoustic Sub-Bottom Data in Riverine Environments: Identification of Underlying Rocky Hazards at Cape Girardeau, Missouri, and Thebes, Illinois

ABSTRACT: Shallow acoustic reflection (chirp) data have been utilized to map the elevation of underlying stratigraphy in a wide range of aqueous environments. Of particular concern in riverine regions is the elevation of near-surface underlying rock that, if exposed during normal migration of sedimentary bedforms, can cause grounding and damage to vessels transiting the region during periods of low water. Given the ephemeral nature of the rock’s exposure, traditional surveying methods are insufficient to map rock when it is covered by a thin veneer of sediment, increasing the potential hazard. Accordingly, the US Army Corps of Engineers, St. Louis District, (MVS) explored the use of chirp sub-bottom surveys to identify buried rock within the Mississippi River in the vicinity of Cape Girardeau, MO, and Thebes, IL. Hazard maps showing the distribution of buried rock were generated, and the base of the mobile sediment layer was identified where possible. These data will allow MVS to accurately identify potentially hazardous regions during periods of low water. Although the study did not result in the complete mapping of all near-surface geologic hazards, regions that warrant further study are identified, and modifications to the original survey plan are provided to improve the accuracy of future data collection efforts.

20 Apr 2020

PUBLICATION NOTICE: Bed-Load Transport Measurements on the Chippewa River Using the ISSDOTv2 Method

PURPOSE: This Regional Sediment Management (RSM) Technical Note (TN) provides information on bed-load measurements obtained on the Chippewa River, Wisconsin, in the spring of 2018. The ISSDOTv2 method was developed by the U.S. Army Corps of Engineers (USACE), Engineering Research and Development Center (ERDC), Coastal and Hydraulics Laboratory (CHL), River and Estuarine Engineering Branch. The method uses time-sequenced bathymetric data to determine a bed-load transport rate. When transport rates are obtained with concurrent flow-rate data, it is possible to develop bed-load rating curves. Such rating curves are extremely valuable in forecasting or hindcasting bed-load sediment delivery for the location at which the data were obtained. This is very important for river managers in developing sediment budgets and in the planning of dredging operations.  In the present study, the USACE Mississippi Valley Division (MVD), St. Paul District (MVP), had contracted with the U.S. Geological Survey (USGS) for real-time monitoring of suspended-sediment concentrations (suspended sand load and bed-load sediment) on the lower Chippewa River, a major source and contributor of sand-sized sediment to the Upper Mississippi River (UMR). The bed-load values obtained using ISSDOTv2 are presented in this RSM TN.