At a time when Congress is fleshing out the final details of a significant investment in the nation’s infrastructure, Dr. Todd Bridges, Senior Research Scientist for the U.S. Army Corps of Engineers, offered testimony on how infrastructure projects built using natural elements may be the best solution to key infrastructure challenges moving forward.
Speaking to members of the Senate’s Committee on Environment and Public Works, Bridges, who leads USACE’s Engineering With Nature® (EWN) initiative, said the initiative was created to “advance opportunities to implement nature-based solutions for civil works projects.”
“We have examples of projects that go back decades, even 100 years which are utilizing the principles and practices that we associate with what we call ‘Engineering With Nature’ today,” Bridges told committee members. “And what we are endeavoring to do through the initiative is to make the exceptional projects of the past more common place in the future and find a more harmonious arrangement between the natural and the engineered.”
In his testimony, which focused on the role of natural and nature-based features in water resources projects, Bridges said environmental challenges faced by communities and planners around the country vary and at times include more than one challenge at a time.
“We have to find infrastructure solutions that address the spectrum from flooding, from drought, and fire, and I believe the data and experience that is being accumulated worldwide indicates that nature-based solutions have a role to play across that entire spectrum,” he said. “The opportunity before us is how to bring all those solution sets together and to integrate. We have to have innovation to address the spectrum and the intensity in advance, in combination.
“There was a time when natural hazards presented themselves to us as ‘onesies,’ but now we deal with ‘twosies’ and ‘moresies,’ which is a challenge for conventional infrastructure solutions.”
In addressing existing infrastructure challenges, Bridges described the initiative’s collaboration and partnerships from across the federal government, academia, the private sector and elsewhere.
“Dialogue and collaboration with the private sector and industry leaders, non-profits and financial institutions are advancing our understanding of where and how nature-based solutions work within their business models and how those lessons may apply to USACE and Army programs,” Bridges said. “Collaborating across the Department of Defense is helping expand the application of nature-based solutions to support its mission. Specifically, we are working with the Defense Advanced Research Projects Agency (DARPA) to develop reef-mimicking systems to mitigate coastal flooding, erosion and related storm damage to DOD and neighboring civilian infrastructure. Similarly, we are working with the Air Force as part of its $5-billion rebuild of Tyndall Air Force Base following the destruction of Hurricane Michael by applying Engineering With Nature to demonstrate, on the ground and in the water, the resilience function that can be generated through natural-based solutions.”
In addition to ongoing projects, Bridges gave examples of how already existing natural features saved communities millions in damages from severe weather events.
“Studies have estimated that the wetlands along the northeast Atlantic Coast helped to avert $625 million of flood damage during Hurricane Sandy and that the 500,000 acres of mangroves around Florida helped to avert more than $1.5 billion in flood damages during Hurricane Irma in 2017,” he said.
As an example of an EWN project already completed and providing key environmental benefits, Bridges highlighted the beneficial use of material dredged from a federal navigation channel in south Louisiana to create a mid-river island. Horseshoe Bend Island in Louisiana created more than 80 acres of habitat.
In California, projects near the former Hamilton Army Air Base and Sears Point restored 1,500 acres of wetlands, providing coastal resilience in the face of rising sea levels.
During the hearing, Bridges was asked about the long-term maintenance costs of nature-based projects compared to more traditionally constructed projects.
“Wetlands have existed for millennia, and so when we approach the design of these systems, these nature-based systems, we want to follow Mother Nature’s lead so that these projects, these features within the projects, can be sustained over time,” he said. “Maintenance of projects over decades is an area of uncertainty for conventional as well as nature-based and something that we look forward to gaining more experience on.
“We have recently gone back to some decades-old projects, where we have beneficially used, for example, sediment dredged from projects to build islands and wetlands in the 1970s. We’ve gone back to those projects recently to look at how those projects perform, and, in fact, they performed quite well.”
As the federal government looks at key infrastructure investments and environmental policies, Bridges said EWN is focused on finding innovative solutions to some of the nation’s toughest challenges.
“Conventional infrastructure, if I can paint with a broad brush, more frequently is single purpose in its orientation, at least that was more characteristic of the 20th Century approach to conventional infrastructure,” he said. “What we need are solutions that can address this spectrum and the multiple hazards that can present themselves in very short periods of time, even within one year of each other.”
The Senate’s Committee on Environment and Public Works is chaired by U.S. Sen. Tom Carper (D-Del.). U.S. Sen. Shelley Capito (R-W.Va.) is the ranking member.