Submerged aquatic vegetation (SAV) habitats provide a variety of important ecosystem services, including fish habitat, nutrient sequestration, and protection from currents and waves. Some research suggests that open-water sediment placement of dredge material harms SAV habitats in the short-term, while other research suggests long term protective benefits that results in an increased and denser area of SAV coverage. This project will evaluate historical, ongoing, and future innovative dredging and placement activities in various geographical locations to more fully distinguish between short-term and long-term impacts to SAV habitat. The project aims to elucidate innovative approaches for sediment placement of dredge material for the purpose of promoting the long-term protective benefits to SAV habitat and the associated environmental, social, and flood risk reduction benefits.
The US Army Corps of Engineers (USACE) Engineering With Nature® Program works to better integrate traditional and nature-based infrastructure approaches by aligning engineering and natural processes for greater benefit.
A multi-sector contribution to practical guidance on formulating, evaluating, and delivering integrated water resources projects. Review the Summit.
Challenge
Current practice in benefit-cost analysis (BCA) is ‘tuned’ for evaluating the economic (dollar value) of costs and benefits produced by traditional, ‘hard’ infrastructure projects. However, the science and practice of quantifying the economic, environmental, and social benefits and costs of nature-based solutions has grown dramatically in recent years. If these advancements were implemented, they could provide a more complete assessment of how nature-based solutions can add value as a part of infrastructure systems.
This applied policy research study will evaluate and apply methods for documenting a comprehensive range of economic, environmental, and social benefits that nature-based solutions can provide. Specific consideration will be given to instances in which nature-based solutions are strategically designed to work with, in an integrated fashion, conventional infrastructure approaches.
Delivering infrastructure to sustain our communities, economy and environment calls upon us to innovate, modernize and even revolutionize our approach to infrastructure development. Partnering WITH nature is a vital part of delivering those solutions in the 21st century.
Lt. Gen. Scott Spellmon, Chief of Engineers and Commanding General of the USACE, from his foreword to the recently published Engineering With Nature Atlas Volume 2
A rendering of potential nature-based solution at Franklin Lock and Dam in SAJ. The mangrove islands with boardwalk provide increased habitat for Wood Stork and Snail Kite, educational and recreational opportunities. Learn more about mangrove research.
Approach
The USACE EWN® Program has partnered with The Water Institute of the Gulf to analyze past and current benefits evaluation approaches to identify practical options for improving federal practice for evaluating the economic, environmental, and social benefits of natural infrastructure and nature-based solutions. The team is evaluating completed USACE Feasibility Studies / Chief’s Reports to identify opportunities to support comprehensive benefits evaluation for nature-based solutions and infrastructure projects, including factors that may have contributed to prioritizing conventional over natural infrastructure as well as benefits that are not being captured as a part of current practice.
Six Chief’s Reports, from a group of 150 completed USACE Feasibility Studies, have been selected for further analysis within the study. These reports encompass navigation, coastal storm risk management, flood risk management, and ecosystem restoration missions within USACE.
Selected Historical Planning Studies
Jacksonville Harbor (NAV, Sourtheast)
Jamaica Bay Reformulation (CSRM, North East)
Southwest Coastal (CSRM, Gulf Coast)
South Platte River and Tributaries (FRM, Northwest)
West Sacramento (FRM, Pacific)
South San Francisco Bay Shoreline (FRM, Pacific)
Based on insights gathered in analyzing nature-based alternatives and comprehensive benefits within these six Chief’s Reports, the team will identify opportunities and options for advancing practice for evaluating comprehensive benefits and costs.
Engineering With Nature emphasizes that current infrastructure project evaluations can be more robust and potentially more protective if costs and benefits of these projects are fully evaluated for the cumulative economic, environmental, and social benefits. EWN does not replace the need for fully engineered concrete infrastructure, but it recognizes that nature-based infrastructure can complement traditional methods for an outcome that is greater than its parts. For example, when a concrete flood wall is designed to include an expansive reef and marsh in front of it, the wall provides flood protection benefits during storms while the reef and marsh system reduce the power of waves, self-adjusts to rising seas, captures carbon, improves water quality, and provides recreational opportunities.
Flooding of Watsonville and agricultural land along the Pajaro River following the March 1995 storm. Learn more about Pajaro River Flood Risk Management.
Horseshoe Bend Island, Atchafalaya River, LA. The river’s current disperses dredged sediment intentionally placed upriver reducing dredging requirements and creating an island with enriched wildlife. (Photo: Great Lakes Dredge and Dock Company) Read more.
Outcomes
This project will provide USACE a baseline to identify how nature-based projects have been evaluated in the past, potential obstacles to advancing practice, and outline how a more comprehensive evaluation of project benefits and costs could provide opportunities to expand and diversify the value provided by infrastructure projects through the inclusion of nature-based solutions.
Engineering With Nature is planning a National Summit on Comprehensive Benefits Evaluation in Washington D.C. during the fall of 2022 to share the results of this study and to invite other federal and state agencies and private sector organizations to share what they are learning about comprehensive benefits evaluation for nature-based solutions.
Products
This study is on-going, additional products and information will be added here.
This report examines: 1) the evolution of USACE’s mission and the related authorities, policies, and practices for using BCA; 2) how challenges in using BCA outside of USACE influence the integration of NBS; and 3) gaps and obstacles within law and policy to further the implementation of NBS projects.
The third in a series, this report provides methodological guidance for the retrospective case study analysis and should be of interest to technical readers at USACE, other federal agencies, and interested stakeholders. The report describes recent and relevant decision analysis methods designed to inform decision makers when considering or trading off among multiple objectives when prioritizing water resources projects.
The Corps of Engineers has a proud history of Engineering With Nature and we are honored to work closely with our colleagues across the Corps to collaboratively develop practical tools that support measuring this full range of benefits.
Justin Ehrenwerth, the Water Institute president and CEO
A process to incorporate the benefits of nature for human wellbeing will help USACE achieve more comprehensive benefits accounting and therefore more informed project evaluation. Ideally this work, in combination with related work units, will continue to increase the EWN-centric portfolio and will support important shifts in public infrastructure planning currently underway in the nation including greater consideration of equity.
The Natural Infrastructure Opportunities Tool (NIOT) is a public facing, web-based decision support tool that allows users to explore data relevant to Natural Infrastructure (NI) projects, as well as view or add NI resource or project needs. The tool includes national and regional datasets and can be adapted for regional use or fine-tuned for local application. It aims to make connections between stakeholders with resources and those in need of resources. This project will expand the tool to include a series of coastal and inland case studies and NI project opportunities, and incorporate user feedback to make the tool more comprehensive and helpful to a wide variety of users. Updating the NIOT viewer and deliberately highlighting how it can be used to plan and implement NI projects will ultimately improve NI projects and benefit the environment, economy, and public and private stakeholders.
Shoreline erosion and reservoir sedimentation is a major issue within reservoirs and lakes, and there are no existing guidelines available to establish priorities to treat excessive shoreline erosion. Sedimentation negatively affects reservoir and lake storage capacity, water quality, recreational activities, and fisheries. This project will develop, test and monitor NNBF projects to provide new and improved methods for stabilizing eroding shorelines. Special emphasis will be placed on incorporating in-situ material materials and enhancing toe protection designs with vegetative, woody and other natural components. In addition, high-resolution terrain data will be analyzed to determine shoreline stability trends which will assist in determining the type and location for future EWN practices. The outcome of this study will be documented to provide other practitioners with appropriate shoreline erosion alternatives and applications using EWN-NNBF techniques.
Wildfires can cause extreme loss of vegetation and soil instabilities that make affected areas highly susceptible to increased runoff, flooding, and transport of debris, and reduced quality of aquatic and terrestrial habitat and water quality. Managing wildfire recovery efforts by applying EWN principles has the potential to provide a wide range of flood risk management benefits while increasing co-benefits for the entire watershed. This project will develop, test and monitor EWN wildfire FRM and erosion control projects to provide state-of-the-art science for future wildfire recovery efforts. Special emphasis will be placed on in-situ material usage for restoration and vegetation management alternatives. In addition a watershed stability tool-FluvialGeomorph will be used to assess the high-resolution terrain data available to determine channel and watershed stability trends which will assist in determining the type and location for EWN practices.
There is currently a lack of information on how to fund or finance natural infrastructure (NI). As NI continues to be mainstreamed, project leads will require innovative financing practices to account for the different lifecycle costs associated with NI projects. This project seeks to identify, evaluate, and share examples of NI projects that have secured the necessary funds from a variety of sources and innovating methods. In particular, this project is exploring the manner in which funds have been secured for scoping, designing, constructing, monitoring, and/or adaptively managing NI projects.
The project intends to showcase a diversity of project types and funding/ financing mechanisms. The library of case studies will increase as additional projects are identified. Practitioners can nominate projects to be featured by contacting the project leads Bari Greenfeld and Margaret Kurth.
Greenfeld BN, Kurth MH, Smith MA, Kalaidjian E, Abellera MS, King JK. (2022) Financing Natural Infrastructure: Exploration Green, Texas. ERDC/TN EWN-22-7. Engineer Research and Development Center (U.S.) Available at https://hdl.handle.net/11681/45601 [Verified on 29 September 2022]
West Bay, Louisiana Sediment Diversion 1945 – 2020
Remote sensing is a technology that allows for the observation of physical attributes of the earth using sensing devices such as cameras or infrared sensors from remote devices like satellites, drones, or aircraft. This research project will help improve the understanding and integration of remote sensing approaches to quantify environmental benefits of EWN® projects. Remote sensing approaches are expected to be instrumental in illustrating and quantifying critical EWN® concepts such as habitat developed as a result of strategically placed dredge material or integrated into engineered structures, NNBF supporting coastal resilience, ecosystem services supporting engineering function, and shoreline conditions from native plantings.
Engineering With Nature® Remote Sensing Technology
The USACE Engineering With Nature® (EWN) program uses remote sensing methods to help practitioners plan projects that align natural processes and engineering capability for greater benefits. Remotely sensed data can reveal changes over the life of a project to quantify benefits and communicate project outcomes. USACE spends billions each year to alleviate the effects of sea-level rise on coastal marsh and barrier islands that provide engineering and environmental function. Incorporating EWN principles into these projects often produces more efficient and sustainable benefits for communities while accomplishing the mission.
Alton Lake in lower Pool 26 on the Mississippi River in August 2017. (Photo by Ben McGuire, USACE St. Louis District)
The practice of managing reservoir and navigation pools to increase wetland habitat value while maintaining safe navigation and managing flood risk is referred to as Environmental Pool Management (EPM). EPM can be a cost-effective way to increase ecosystem goods and service (EGS) benefits in lake and reservoir systems. But water quality benefits from EPM best practices are not well understood. This project will demonstrate and communicate the EGS benefits of EPM via a case study using the Lake Red Rock EPM conceptual model. This project will also evaluate water quality parameters and de-nitrification rate response to EPM. Communications will target USACE lake managers, district Operations Chiefs, and Command staff responsible for water management decisions, and will capture the EWN® triple-win elements of engineering, environmental, and social benefits that can be derived from sustainable EPM practices.
View West to Point Hope
(palm_ak, CC BY 3.0 https://creativecommons.org/licenses/by/3.0, via Wikimedia Commons)
Cold Region (CR) environments experience unique environmental stressors such as loss of permafrost and ice sheets from climate change, sea-level rise, intense ice and snowstorms, high winds, and rising/falling lake levels. These unique conditions often complicate the development of lasting EWN® solutions that improve Cold Region resilience. This project aims to identify and develop new and non-traditional EWN strategies that integrate novel natural infrastructure and nature-based techniques and practices specific to Cold Region environments. This project also seeks to better understand the current conditions and future-anticipated changes in Cold Regions in order to obtain greater insight into what EWN strategies might reduce risk and increase the resilience of communities located in Cold Regions such as Alaska, Canada, New England, and the Great Lakes.
Cohn N, Bosche LV, Midgley T, Small C, Douglas TA, and King J. (2022). Assessing drivers of coastal tundra retreat at Point Hope, Alaska. Journal of Geophysical Research: Earth Surface, 127, e2022JF006813. Available at: https://doi.org/10.1029/2022JF006813.
26-30 June 2022. The 5-day event featured field visits, a two-day symposium for development of Canada-specific natural infrastructure guidelines and a workshop to engage critical discourse around the feasibility of nature-based adaptation to climate change by defining successful cases, developing frameworks, and mobilizing collective lessons learned.
