17 Nov 2023

Advancing Engineering With Nature Initiatives in Point Hope, Alaska

Purpose: Growing environmental risk threatens communities in cold regions, particularly as climate change contributes to permafrost thaw, a reduction in sea-ice extent, and some of the largest rates of coastal erosion on earth. In the context of these significant and growing risks, the Engineering With Nature® (EWN®) program formed its cold regions work unit in 2021 to explore the potential to apply EWN approaches in these areas to mitigate environmental risk while supporting resilient outcomes. The work unit’s objectives include working with communities to preserve the natural environment and traditions, advancing the work unit’s understanding of cold-region environments, and providing guidance on the implementation of natural and nature-based features (NNBF) and EWN in cold regions to increase resilience. This technical note (TN) provides an overview of the EWN in cold regions technical approach as applied to Point Hope, Alaska, which includes community engagement, the integration of traditional ecological knowledge (TEK) throughout the project, and the development of cold-regions-specific knowledge and tools.

8 Nov 2023

Environmental Monitoring of Munitions Constituents During a Demonstration of the Underwater Cut-and-Capture System Demilitarization Technology

PURPOSE: The presence of underwater military munitions (UWMM) in aquatic environments may present explosive blast risks and potentially affect the environment because of the release of munitions constituents (MC). Therefore, in situ demilitarization of UWMM is highly desirable. This technical note presents the results of environmental monitoring measuring water and sediment contamination resulting from the demonstration of an in situ technology that uses high-pressure water jets to render UWMM safe.

31 Oct 2023

Marine Bioinvasion Risk: Review of Current Ecological Models

Abstract: This special report describes the first phase of developing an ecological model to inform marine bioinvasion risks in the United States. The project responds to the needs of the US Army Corps of Engineers (USACE) Aquatic Nuisance Species Research Program, or ANSRP, which addresses all problematic invasive aquatic species affecting the nation’s waterways, infrastructure, and associated resources, and the needs of the USACE navigation and dredging programs. Multiple port-deepening studies are either in progress or under consideration, and all must address ecological risk. Understanding whether and how increased dredging contributes to in-creased marine bioinvasion risk allows risk mitigation during early planning phases. Considering the potential impacts of future environmental change, such as changing sea level, ocean temperature, and ocean chemistry, will further strengthen planning for marine bioinvasion risk. There-fore, this special report documents current ecological modeling approaches to marine bioinvasion risk models and identifies models that in-corporate shipping as a vector. The special report then presents a conceptual model and identifies historic vessel position data from the Automatic Identification System, or AIS, now available for most commercial and some recreational vessels around the United States, as a key source for future model development and testing.

31 Oct 2023

Proceedings from the Basin Sediment Management for Unique Island Topography Workshop, Mayagüez, Puerto Rico

Abstract: This report summarizes the Basin Sediment Management for Unique Island Topography Workshop hosted in-person and virtually at the University of Puerto Rico Mayagüez (UPRM) Department of Civil Engineering and Surveying, Mayagüez, Puerto Rico on 11 March 2022. The workshop was attended by approximately 80 federal, state, local, and academic organizations participants. It focused on Engineering With Nature® (EWN®), green infrastructure (GI) and low impact development (LID) opportunities for unique tropical island topography and included seven presentations from subject matter experts, a discussion on limitations and problems with prior projects, and two concurrent breakout sessions. Preworkshop activities included a field trip to multiple sites in the Añasco watershed conducted 09 March 2022, which served as a base case for the workshop. The field trip provided participants a unique perspective of the island’s topography and post 2017 Hurricane María issues and impacts. During the breakout sessions, participants identified new project opportunities for EWN®-GI and LID at two selected sites from the field trip. Each group developed alternatives for their chosen site and identified concepts that could turn into great opportunities for the surrounding communities and significantly benefit the state of practice in Puerto Rico’s unique tropical island topography.

23 Oct 2023

Considering Sediment Beneficial Use Options at Lake Michigan Harbors in Wisconsin

Abstract: In 2020 the US Army Corps of Engineers (USACE) reassigned 14 federally maintained harbors in the Wisconsin waters of Lake Michigan to USACE–Chicago District. The administrative change presents opportunities for in-creased beneficial use of sediment at harbors that have not traditionally placed sediment beneficially. This paper summarizes a screening-level analysis of 12 harbors to determine which harbors are likely to have sediment appropriate for beneficial use in the future, either in water or upland. The harbors were qualitatively ranked according to the potential for future successful beneficial use of navigationally dredged sediment. Using this screening, data needs were defined and next steps to aid the development of a regional dredged-material management plan were identified.

18 Oct 2023

Guidelines for How to Approach Thin-Layer Placement Projects

Abstract: Historically, dredged material (DM) has been placed at the nearest available placement site. There has been an increasing trend of beneficial use projects recently, often using innovative methods. Thin-layer placement (TLP) involves one- to two-foot-thick DM placement, compared to traditional, thicker sediment placement applications, to restore coastal wetlands. The main idea of TLP is to promote the natural recolonization or reestablishment of habitat and benthic species. These guidelines present a roadmap of TLP’s evolution and offer easily digestible examples and considerations for TLP applications in wetlands and open-water environments. Offered as a tool to the practitioner, the eight chapters of these guidelines cover the history of TLP, characterization of the project area, setting goals and objectives, project design, construction considerations, monitoring and adaptive management, knowledge gaps, and future research needs. Several case studies are presented as examples of how such applications have been implemented and highlight lessons learned, particularly best-management practices. These guidelines offer consideration of TLP as a critical component in the project development phase, a tool for the sustainable management of DM, and a method that may create, maintain, enhance, or restore ecological function while supporting navigation channel infrastructure and providing flood risk management benefits.

10 Oct 2023

Pilot-Scale Optimization: Research on Algae Flotation Techniques (RAFT)

Abstract: The impacts of harmful algal blooms (HABs) on US national waterways continue to cause significant economic and environmental damage. Researchers at the US Army Engineer Research and Development Center (ERDC) successfully demonstrated the Research on Algae Flotation Techniques (RAFT) project at pilot scale. This study was designed to show that the surface concentrations of algal biomass can be effectively increased with near linear scalability utilizing the natural methods by which some algae entrap air within excreted mucilage for flotation. The surface concentration of cyanobacteria measured as phycocyanin pigment increased by six-fold after RAFT flocculation treatment. Further optimization of chemical delivery systems, mixing, and dissolved air exposure will be required before full scale readiness.

10 Oct 2023

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.

10 Oct 2023

A Review of Algal Phytoremediation Potential to Sequester Nutrients from Eutrophic Surface Water

Abstract: Harmful algal blooms (HABs) and coastal hypoxic zones are evidence of cultural nutrient enrichment affecting public health and water supplies, aquatic ecosystem health, and economic well-being in the United States. Recognition of the far-reaching impacts of Midwest agriculture has led to establishing nutrient reduction objectives for surface waters feeding the Gulf of Mexico, Lake Erie, and many smaller water bodies. Municipal nutrient enrichment impacts have been addressed by increasing levels of sewage treatment and waste management through the Clean Water Act era, but HABs rebounded in the 1990s because of non-point source nutrient enrichment. HAB control and treatment includes watershed and waterbody treatments to reduce loading and address outbreaks. Systems to remove nutrients from impaired waters are expensive to build and operate. This review of algal production systems summarizes emerging algal water treatment technologies and considers their potential to effectively sequester nutrients and atmospheric carbon from hundreds of eutrophic reservoirs and DoD wastewater treatment facilities while producing useful biomass feedstock using solar energy. Algal water treatment systems including open ponds, photobioreactors, and algal turf scrubbers® can be used to grow biomass for biofuel, wastewater treatment, and commercial products. This review recommends continuing research on surface water nutrient reduction potential with algal turf scrubber productivity pilot studies, preliminary site design, and biomass utilization investigations.

10 Oct 2023

Spatial Screening for Environmental Pool Management Opportunities

Abstract: US Army Corps of Engineers (USACE) reservoir projects significantly alter river ecosystem structure and function. Each project adheres to a defined set of operating rules to achieve primary objectives, which typically include flood risk management, hydropower, or navigation along with ancillary objectives for drinking water/irrigation, recreation, and natural resources management. Environmental flows (E-Flows) planning under the Sustainable Rivers Program has demonstrated new opportunities for environmental pool management (EPM; Theiling et al. 2021a, 2021b) that have no negative impact on other reservoir functions. In some locations, water level drivers can be managed to improve ecological outcomes, like wetlands, waterbirds, reptiles, and water quality, by altering the magnitude, timing, frequency, and duration of pool level changes that affect riparian and shoreline plant communities. Reservoirs with large delta areas may provide particularly important wetland or riparian habitat management along avian migratory pathways or in wildlife conservation regions (Johnson 2002). These large deltas can be identified and characterized using available satellite imagery, which along with water level habitat drivers available in hydrology databases, can be used to identify USACE reservoirs with good potential for EPM. A spatial analysis of USACE reservoirs capable to support EPM can be developed utilizing estimates of water occurrence, transition, and seasonality as well as surface elevation data derived from satellite imagery to assess geomorphology drivers. USACE water management records can be used to assess wetland drivers. Nationwide screening will be broken down into ecoregions to establish the anticipated geographic range of variation for wetland and riparian habitat drivers. Southwestern US reservoirs, for example, will have much different hydrology and fauna than Midwest and Eastern US reservoirs.