Nearly four years ago, a team led by the U.S. Army Corps of Engineers and that now includes 189 scientists, engineers and resource managers from 73 worldwide organizations gathered to begin work on a set of international guidelines for utilizing Natural and Nature-Based Features.
Today, the project is nearing completion with the publication of “Guidelines on the Use of Natural and Nature-Based Features for Sustainable Coastal and Fluvial Systems” expected in 2020. The guidelines will provide practitioners with the best available information concerning the conceptualization, planning, design, engineering, construction and maintenance of NNBF to support resilience and flood risk reduction for coasts, bays and estuaries, as well as river and freshwater lake systems.
“Until this project, there was no comprehensive set of NNBF guidelines available to support practitioners and stakeholders interested in these types of solutions,” said Dr. Jeff King, deputy national lead for the Engineering With Nature® Initiative.
A part of the EWN® Initiative, NNBF refers to those coastal and fluvial, or river system, landscape features, either natural or nature-based, that produce flood risk management and other benefits. Natural features are those created by nature; nature-based features are engineered by people to mimic natural conditions. NNBF projects provide multi-purpose functions related to flood and storm damage reduction and ecosystem restoration. They are designed to simultaneously deliver economic/engineering, social and environmental benefits.
A few examples of coastal NNBF are beaches and dunes, salt marshes, oyster reefs and barrier islands. Fluvial NNBF⸺ in addition to floodplain restoration in rivers and streams⸺ include a range of features to detain and retain floodwaters or otherwise create space for water.
“The public increasingly has an interest in these types of projects,” King said. “Rather than looking solely at traditional infrastructure, knowing that it may have unintended impacts down the road, communities are saying, ‘Mother Nature does such a great job at solving problems; we should really be looking at what she does and simulate it.’”
EWN National Lead Dr. Todd Bridges described how the National Oceanic and Atmospheric Administration’s National Centers for Environmental Information tracks economic damages exceeding $1 billion that result from weather-climate events.
“Since 1980, there have been 219 weather-climate catastrophes that have collectively produced $1.5 trillion in damages⸺ that’s a big number,” Bridges said.
“We have to ask, what strategies can we employ to reduce future impacts?” Bridges continued. “We can’t build walls everywhere, there are practical limits to the use of conventional infrastructure. We need to identify ways to leverage natural systems in combination with structural measures.”
The Corps is hearing from local sponsors who are increasingly interested in integrating NNBF into projects.
“We have these major functional areas within the Corps: planning, engineering and operations,” Bridges said. “We’re addressing all of those topics within the guidelines in a way that demonstrates and documents the design, performance and quantified benefits of NNBF.”
King sees this area as a newly developing field of engineering.
“The U.S. Army Engineer Research and Development Center is doing research and field studies to answer questions about the design and associated benefits of these features,” King said. “Several USACE districts are very hungry to advance NNBF practices, but are challenged to quantify why the practices should be incorporated into projects.”
Illustrating the international collaborative nature of the effort, contributors and co-leads for the project are from a variety of countries: the United States, Canada, the Netherlands, the United Kingdom, New Zealand; additional contributors are from countries such as the Democratic Socialist Republic of Sri Lanka and the Republic of South Korea.
One international collaborator is Dr. Jo Guy, the Environmental Agency of England’s international lead for natural flood management⸺ which is the United Kingdom’s equivalent of NNBF. EA personnel are contributing to six chapters in the publication.
When asked why the EA has an interest in contributing to the guidelines, Guy mentioned that the EA intends to be a net-zero carbon emissions organization by 2030.
“NNBF will allow us to achieve this goal and deliver solutions that make communities resilient to flooding and able to adapt to the effects of climate change,” Guy said.
The guidelines are written for a varied audience, so that a city manager or community developer who may not have a technical background will gain critical knowledge to pursue these types of projects and to assemble the appropriate technical teams.
The NNBF guidelines will be a living document hosted on a website and will be approximately 600 pages long. The publication will have 19 chapters divided into three sections: Overarching Topics, Coastal Features and Fluvial Features. Case studies will also be integrated to demonstrate the application of features.
“We anticipate revisions and additions to the publication every three to four years⸺this is such a developing body of knowledge,” King said. “We will also write a printable 20-page summary for higher-level decision makers.”
Bridges noted that there is tremendous interest worldwide in utilizing NNBF.
“There is a large and growing base of knowledge, experience and expertise around the world in using NNBF,” Bridges said. “With this project, we are leveraging that base to produce guidelines that will benefit the entire international community of practitioners.”
For more information about the EWN initiative, please visit www.engineeringwithnature.org