Results:
Tag: Dredged Material
Clear
  • Effects of Suspended Sediment on Aquatic Organisms: A Literature Review and Database Effort

    Abstract: The US Army Corps of Engineers (USACE) acknowledges that uncertainties and public perceptions regarding the effects of suspended sediment on aquatic organisms, particularly the concentration thresholds associated with harmful effects, present an ongoing challenge to its dredging mission. USACE is actively working to address these challenges through improved monitoring, research, and collaboration to support safer and more sustainable dredging practices. To help mitigate this uncertainty, 159 field- and laboratory-based studies describing the effects of sediment on aquatic organisms were reviewed and compiled in a database. No- and low-effect ecotoxicity data from this review were further analyzed to determine percentiles of effects data and species sensitivity distributions. The analysis indicated corals and freshwater crustaceans were most sensitive, followed by fish, while bivalves and marine crustaceans appeared to be the most tolerant of suspended sediment. This literature review provides a foundational framework for visualizing site-specific suspended sediment thresholds for effects concentrations associated with potential effects on aquatic species. It serves as a starting point for identifying critical data gaps for future research, layering in additional data, refining thresholds, and supporting more informed, site-specific decision-making moving forward.
  • Corps of Engineers seeks comments on moving dredged material in Pool 3

    ST. PAUL, Minn. – The U.S. Army Corps of Engineers, St. Paul District, is seeking comments on a draft Environmental Assessment, or EA, for the unloading of dredged material, or river sand, from its Corps Island placement site in Pool 3 of the Upper Mississippi River, located near Red Wing, Minnesota.
  • U.S. Army Corps of Engineers responds to request for emergency dredging of Maryland’s Ocean City Inlet

    The U.S. Army Corps of Engineers (USACE), Baltimore District, received emergency request approval to use USACE, Wilmington District’s dredge MERRITT to remove ~7,500 cubic yards of dredged material from the Ocean City Inlet this July.
  • Beneficial Use of Dredged Material for Submerged Aquatic Vegetation Habitats: Overcoming Challenges and Seeking New Opportunities

    Purpose: There is a critical need to maintain and create conditions that are conducive for long-term survival of submerged aquatic vegetation (SAV) habitats, which provide multiple ecosystem services, using dredged material. This technical note (TN) was developed by the US Army Engineer Research and Development Center (ERDC)–Environmental Laboratory (EL) to address the specific challenges US Army Corps of Engineers (USACE) practitioners at the district and division level face that impede the development of beneficial use of dredged material (BUDM) projects to restore, conserve, and expand SAV habitats. Different ways to overcome these challenges and opportunities that should be further explored are also addressed. The information in this TN was synthesized from discussions at a virtual workshop for USACE practitioners.
  • Conway Lake Ecosystem Restoration: Soil Investigations to Support Engineering With Nature and Beneficial Use of Dredged Sediment

    Purpose: The purpose of this Technical Note is to describe Conway Lake ecosystem restoration adaptive management investigations to evaluate forest planting and soil response to three depths of fine sediment placed over a sand base.
  • A Review of Habitat Modeling Methods That Can Advance Our Ability to Estimate the Ecological Cobenefits of Dredge Material Placement

    Abstract: Beneficial use of dredged material (BUDM) has been a placement strategy within the USACE for over 35 years, with applications that aim to reduce navigation costs, increase flood protection, and generate ecological benefits. However, the tools and approaches used for estimating ecological benefits are often limited in comparison with those available to evaluate costs and more traditional economic benefits when moving and placing dredged material. There are statistical and mechanistic models that can aid in quantifying habitat benefits within the context of BUDM projects, but there is currently no USACE-approved process that facilitates the integration of these modeling approaches. The purpose of this document is to provide a comprehensive review of existing habitat-centric statistical and mechanistic models that may aide the USACE in identifying models most appropriate for quantifying potential ecological benefits and trade-offs at placement sites.
  • Next-Generation Water Quality Monitoring during Dredging Operations: Knowns, Unknowns, and Path Forward

    Abstract: Water quality monitoring data are routinely collected during dredging and placement operations to address various state and federal requirements, including water quality standards, with the intention of protecting ecosystem health. However, such efforts may be limited by the lack of a standardized national strategic focus and user-friendly streamlined interfaces to interpret the data. Inconsistencies in how and what data are collected and lack of consensus on scientifically backed biological-effects thresholds make it difficult to quantify potential dredging operations impacts (or lack thereof) both within individual projects over time and across multiple projects of differing characteristics. Summarized herein is an initial effort to define a scientifically backed path forward to improve the value of current and future water quality monitoring and management decisions based on water quality data collected. The provided turbidity data were generally below applicable state thresholds for two case studies but for a third case study did periodically exceed thresholds at depth. This includes providing rationale for strategic focus on the most relevant dredging operations and projects, based on three general site-specific data categorizations: (1) sediment type, (2) dredge type, and (3) ecosystem type.
  • Site Selection and Conceptual Designs for Beneficial Use of Dredged Material Sites for Habitat Creation in the Lower Columbia River

    Abstract: Channel maintenance in most major rivers throughout the United States requires ongoing dredging to maintain navigability. The US Army Corps of Engineers explores several options for placement based on sediment characteristics, material quantity, cost, operational constraints, and minimization of potential adverse effects to existing resources and habitat. It is a priority to beneficially reuse dredged sediments to create habitat and retain sediments within the river system whenever possible. Nonetheless, there can be discrepancies among state and federal resource agencies, landowners, tribes, and various other stakeholders about what constitutes a benefit and how those benefits are ultimately weighed against short- and long-term tradeoffs. This work leveraged prior Regional Sediment Management efforts building consensus among stakeholders on a suite of viable strategies for in-water placement in the lower Columbia River. The goal was to identify suitable locations for applying the various strategies to maximize habitat benefits and minimize potential adverse effects. A multistep site-selection matrix was developed with criteria accounting for existing site conditions, overall placement capacity, tradeoffs, long-term maintenance, cost, stakeholder concerns, and landscape principles in the context of other habitat restoration projects implemented in the lower river. Three highly ranked sites were selected for conceptual design and exemplify results of collaborative beneficial use implementation.
  • Coastal Breeding Bird Phenology on the Dredged-Material Islands of the Baptiste Collette Bayou, US Army Corps of Engineers, New Orleans District, Louisiana

    Abstract: Coastal bird populations in North America have experienced significant population declines over the past four decades, and many species have become dependent upon human-made islands and other sediment-based habitats created through dredged material deposition. We monitored the breeding phenology of coastal bird populations utilizing dredged-material islands and open depositional areas in the Baptiste Collette Bayou in coastal Louisiana. Monitoring began in early May, prior to when most coastal species begin nesting, and continued through late August, when most breeding activity has ceased. Semimonthly surveys included area searches by foot and boat. Two deposition areas and one island supported large numbers of foraging, roosting, or breeding birds; surveys on these areas included using spotting scopes to identify species and count nests or young. Six islands and two open deposition areas were monitored. We also collected high-definition and lidar imagery using an uncrewed aerial system (UAS) in June, during peak nesting season. We recorded 77,474 cumulative detections of 68 species. Virtually all colonial nesting birds (terns and skimmers) nested on Gunn Island in 2021. We discuss these results in the context of dredged-material deposition by the US Army Corps of Engineers, New Orleans District, and offer recommendations for management of these areas.
  • Proceedings from the Soft Substrate Island Design Workshop

    Abstract: This report summarizes the activities of the Soft Substrate Design Workshop held virtually on 08 September 2021. The 28 participants from federal, state, local, and academic organizations discussed designing and constructing islands with soft sediments in inland waterways. They were introduced to the US Army Corps of Engineers’ (USACE) Engineering With Nature® (EWN®) initiative and the vision for Tri-County Planning Commission (Peoria, Illinois). An overview of collaborative projects using landscape architecture and EWN principles was provided. The focus of discussion was on two primary waterways, the Upper Mississippi River System, and Illinois River. Participants discussed their experience associated with designing and constructing islands with and on soft sediments prior to breakout sessions to discuss specific design and contracting elements. The groups were brought together to discuss design techniques that could be implemented in the Upper Mississippi River and Illinois River systems.