4 Aug 2022

Engineering With Nature® Principles in Action: Islands

Abstract: The Engineering With Nature® (EWN) Program supports nature-based solutions that reduce coastal-storm and flood risks while providing environmental and socioeconomic benefits. Combining the beneficial use of dredged sediments with the restoration or creation of islands increases habitat and recreation, keeps sediment in the system, and reduces coastal-storm and flood impacts. Given the potential advantages of islands, EWN seeks to support science-based investigations of island performance, impacts, and benefits through collaborative multidisciplinary efforts. Using a series of case studies led by US Army Corps of Engineers (USACE) districts and others, this technical report highlights the role of islands in providing coastal resilience benefits in terms of reducing waves and erosion as well as other environmental and socioeconomic benefits to the communities and the ecosystems they reside in.

4 Aug 2022

Supporting Bank and Near-bank Stabilization and Habitat Using Dredged Sediment: Documenting Best Practices

Abstract: In-water beneficial use of dredged sediment provides the US Army Corps of Engineers (USACE) the opportunity to increase beneficial use while controlling costs. Beneficial use projects in riverine environments include bank and near-bank placement, where sediments can protect against bank erosion and support habitat diversity. While bank and near-bank placement of navigation dredged sediment to support river-bank stabilization and habitat is currently practiced, documented examples are sparse. Documenting successful projects can support advancing the practice across USACE. In addition, documentation identifies data gaps required to develop engineering and ecosystem restoration guidance using navigation-dredged sediment. This report documents five USACE and international case studies that successfully applied these practices: Ephemeral Island Creation on the Upper Mississippi River; Gravel Island Creation on the Danube River; Gravel Bar Creation on the Tombigbee River; Wetland Habitat Restoration on the Sacramento-San Joaquin River Delta; and Island and Wetland Creation on the Lower Columbia River Estuary. Increased bank and near-bank placement can have multiple benefits, including reduced dredge volumes that would otherwise increase as banks erode, improved sustainable dredged sediment management strategies, expanded ecosystem restoration opportunities, and improved flood risk management. Data collected from site monitoring can be applied to support development of USACE engineering and ecosystem restoration guidance.

29 Jul 2022

Chitosan as a Coagulant and Precipitant of Algae Present in Backwater

PURPOSE: : The purpose of this technical note (TN) is to highlight the current state of knowledge of algal flocculation by chitosan and identify data gaps existing between specific algal characteristics and chitosan binding efficiency. Published relationships and correlations between the quality of backwaters and the prevalence of algae, a baseline for flocculation efficiency of microalgae, and ideal treatment instances for algal removal by way of chitosan flocculation and precipitation will be identified.

29 Jul 2022

Organogel Synthesis Towards Electrochemical Sensing Applications

PURPOSE: The purpose of this study was to synthesize a novel and tunable organogel system capable of stand-alone use with integration via electrochemical tools for the detection of aerosol particles.

27 Jul 2022

Synthesis of 2-methoxypropyl benzene for epitope imprinting

PURPOSE: To synthesize a novel, yet simple, compound for use in the development of a molecularly imprinted sensor for field-portable detection of harmful algal bloom toxins. BACKGROUND: Harmful algal blooms (HABs) are occurring with increasing frequency and severity across the globe in part due to climate change and anthropogenic pollution (Bullerjahn et al. 2016). HABs produce several classes of toxins; however, microcystins (MCs) are the most commonly studied (Lone et al. 2015) and can be potent toxins with LD50s in the range of 50 μg/kg (Puddick et al. 2014). Sample analysis in laboratories, typically by high-pressure liquid chromatography tandem mass spectrometry (HPLC-MS/MS) or by Enzyme Linked Immunosorbent Assays (ELISAs) (USEPA 2015). These analytical techniques are highly sensitive and selective for the given toxins; however, the time it takes to collect, transfer, prepare, and analyze a sample before the data can be reported is significant; often, multiple days is the most expeditious.

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.

25 Jul 2022

The Application of Engineering With Nature® Principles in Colorado Flood Recovery

Purpose: This technical note features river-based restoration projects that incorporate Engineering with Nature® (EWN®), Natural and Nature Based Features (NNBF) approaches in the Front Range of Colorado as part of a comprehensive flood recovery program to protect life and property.

25 Jul 2022

Engineering With Nature® in Fluvial Systems

Purpose: The purpose of this technical note is to underline the growing need for Engineering With Nature® (EWN) guidance for inland fluvial systems. In comparison to the EWN coastal initiatives, guidance, and technical publications, emphasis on inland fluvial systems has been primarily focused on larger river systems, rather than smaller and intermediate-sized tributary systems. As EWN continues to expand its offerings and support inland systems, there is a strong need to fill data gaps and offer case study examples from underrepresented issues across different hydro-physiographic regions and ecosystems. Accordingly, this technical note offers background on the growing need for riverine EWN guidance as well recommendations moving forward to help address those needs.

21 Jul 2022

Implementing Endangered Species Act (ESA) Section 7 (a)(1) Conservation Planning During US Army Corps of Engineers (USACE) Coastal Engineering

Purpose: This technical note was developed by the US Army Engineer Research and Development Center–Environmental Laboratory (ERDC-EL) to provide guidance to the US Army Corps of Engineers (USACE) on implementing Endangered Species Act* (ESA) Section 7(a)(1) conservation planning, in coordination with the US Fish and Wildlife Service (USFWS) and the National Marine Fisheries Service (NMFS) during coastal engineering projects. USACE expends ~$200–$300 million each year on compliance, conservation, and other activities associated with the ESA (USACE 2022), and these expenditures often exceed those of other federal agencies (for example, US Bureau of Land Management) that have jurisdiction over far greater land holdings than USACE. To streamline the ESA compliance process, lower costs, and generate more positive outcomes for federally listed threatened and endangered species (TES), USACE was directed in June 2015 by the Deputy Commanding General (DCG) for Civil and Emergency Operations to proactively identify and incorporate conservation benefits into all projects when and where opportunities arise, under the authority of Section 7(a)(1) of the ESA (USACE 2015). The DCG identified Section 7(a)(1) conservation planning as a mechanism to efficiently achieve project purposes, create environmental value, and streamline the ESA Section 7(a)(2) consultation process

20 Jul 2022

Scenario Analyses in Ecological Modeling and Ecosystem Management

Purpose: Ecosystem management and restoration practitioners are challenged with complex problems, diverse project goals, multiple management alternatives, and potential future scenarios that change the systems of interest. Scenario analysis aids in forecasting, evaluating, and communicating outcomes of potential management actions under different plausible conditions, such as land-use change or sea level rise. However, little guidance exists for practitioners on the utility and execution of scenario analysis. Therefore, this technical note highlights the usefulness of scenario analysis as a tool for addressing uncertainty in potential project outcomes. The mechanics of the scenario-analysis process are explained, and examples of different types of scenario analyses are described for context on the breadth of its use. Lastly, two hypothetical case studies of scenario analysis in ecological modeling are presented showing a semiquantitative approach for assessing anadromous fish and a quantitative approach examining freshwater mussel habitat. Overall, this technical note provides a brief review of the utility and application of scenario analyses in the context of ecological modeling and ecosystem management decision-making.