2 Dec 2024

Establishing a Workflow for Near-Seamless Digital Elevation Model Creation in the Great Lakes for ADCIRC Modeling

Abstract: This report introduces a workflow to create near-seamless, regional digital elevation models (DEMs) for use in coupled Advanced Circulation and Simulating Waves Nearshore modeling. The workflow is based in Esri ArcGIS Pro, leveraging the Mosaic Dataset architecture to organize and mosaic survey data sets into near-seamless DEMs. This workflow includes data collection and preprocessing, creation of source and derived mosaic data sets, manual editing of the data set seamlines, the creation of spatial metadata products, and quality assurance and control measures. These steps were implemented for each Great Lake to provide a high-resolution, near-seamless DEM product for modelers. The workflow may also have utility for other regional-scale investigations.

5 Nov 2024

Improving Aquatic Placement Practices for Beneficial Use of Dredged Material in the Great Lakes

Abstract: The Great Lakes Navigation System is an economically critical waterway. To maintain safe and navigable waterways, approximately 3–5 million yd3 (2.3–3.8 million m3) of sediments are dredged annually. The US Army Corps of Engineers (USACE) and others now recognize that beneficial use of these sediments can achieve positive economic, environmental, and social outcomes. However, historically less than 25% of dredged sediments have been beneficially used in the nearshore environment. Improvements are needed in dredged material management practices in the Great Lakes to achieve the goal of using 70% of dredged sediments beneficially by 2030. Therefore, to overcome these challenges this report reviews beneficial use of dredged material projects with the goal of improving and in-creasing beneficial-use-placement practices in the Great Lakes. Identified needs to advance beneficial-use placement in the Great Lakes include the following: (1) improved modeling of sediment-placement methods; (2) better documentation regarding the cost, benefits, and drawbacks of various placement methods; (3) demonstration of some sediment-placement techniques used successfully in other coastal environments; and (4) monitoring before and after conditions, particularly for sediments that contain greater than 10% fines. Several demonstration projects should be implemented to obtain information addressing the data gaps.

18 Sep 2024

Opportunities for Upper Mississippi River System Sand to Support Coastal Beach Nourishment

Abstract: This research presents an opportunity to review the concept, status, and cost of using Upper Mississippi River (UMR) riverine dredged sand to nourish coastal beaches for increased resilience. Several dredged placement sites, transport modes, commercial and industrial uses, and end-point destinations will be identified in regional assessments and several specific UMR sediment to Great Lakes beneficial use projects will be reviewed here and assessed in greater detail during this research investigation.

22 Aug 2024

Application of Existing Tools to Systematically Identify Nearshore Placement Sites for Beneficial Use of Navigation Sediments in Lake Michigan

Purpose: The Great Lakes includes 140 federally maintained harbors with an annual dredging program of 2–4 million cubic meters (3–5 million cubic yards)[1] of sediment. Many small harbors are not dredged regularly, and there is an undredged backlog of over 9 million cubic meters (12 million cubic yards) of sediment (USACE-LRD 2021). Current policy (Spellmon 2023) is to maximize the beneficial use (BU) of sediment, with a goal of beneficially reusing 70% of the federal navigation dredging volume by 2030 (that is, the 70/30 goal). In the Great Lakes, clean sands have often been placed on beaches or in the nearshore littoral zone to beneficially nourish the shoreline, but since many harbors are not dredged regularly, no plans exist to beneficially reuse dredged sediments. This lack of existing BU plans is particularly true for harbors with finer grained or mixed sediment. To achieve the 70/30 BU goal and support navigation maintenance and coastal management requires a strategic and systematic approach to identifying BU sites. The purpose of the technical note is to (1) provide an approach to identify potential nearshore placement sites using existing information and models; (2) describe available tools for placement site identification, coastal condition information, and the long-term fate of the sediment; and (3) provide a pertinent case study to describe this approach in practice.

11 Aug 2022

Environmental Evaluation and Management of Dredged Material for Beneficial Use: A Regional Beneficial Use Testing Manual for the Great Lakes

Abstract: The Environmental Evaluation and Management of Dredged Material for Beneficial Use: A Regional Beneficial Use Testing Manual for the Great Lakes (a.k.a. Great Lakes Beneficial Use Testing Manual) is a resource document providing technical guidance for evaluating the suitability of dredged sediment for beneficial use in aquatic and terrestrial environments in the Great Lakes region. The procedures in this manual are based on the Environmental Laboratory extensive research, working with US Army Corps of Engineers (USACE) Great Lakes districts, state resource agencies, and local stakeholders seeking to develop dredged material beneficial use alternatives consistent with regional needs and goals. This manual is the first guidance document developed by USACE for evaluating the environmental suitability of dredged material specifically for beneficial use placements. It provides a tiered framework for evaluating the environmental suitability of aquatic and upland beneficial uses consistent with the Inland Testing Manual and the Upland Testing Manual. This manual is intended to serve as a regional platform to increase collaborative problem-solving and endorse a common understanding of the scientific and institutional practices for evaluating dredged material for any beneficial use. Dredged sediment may be managed as a valuable resource, with great potential to create economic, environmental, and social benefits.