Webinar Explores Sediment Reuse, Bank Protection

More than 130 people tuned into PIANC USA’s “Sustainable Practices for Navigable Waterways” webinar March 25.

The free webinar is the first offered in 2026 by the United States’ chapter of PIANC, headquartered internationally in Brussels, Belgium. PIANC is the World Association for Waterborne Transport Infrastructure. The acronym PIANC comes from its original name, the Permanent International Association of Navigation Conferences, which was founded in 1855.

Dr. Burton Suedel, a research biologist in the environmental laboratory at the Corps of Engineers’ Engineer Research and Development Center in Vicksburg, Miss., and Dr. Kyle McKay, a project engineer at the international firm Woolpert and the environmental director for the Odom School of Ecology at the University of Georgia, led the session, which focused on how science-based guidance can inform decisions about waterborne infrastructure projects. The speakers focused on two common areas of practice: sustainable sediment management and technical-biological bank protection.

Beneficial Use of Dredged Materials

Suedel began by talking about the beneficial use of dredged materials to help manage sediments in a more sustainable manner.

“Removing material from the federal navigation channel has substantial benefits associated with that, but we’re seeking benefits that go beyond that of simple removal in ways, for example, that can reduce impacts of flood risks, looking for ways of restoring ecosystems and so on and so forth,” he said.

The Corps’ Engineering With Nature program looks for ways navigation projects can become multipurpose value projects. Such projects may be able to better adapt to a changing environment, increase biodiversity or have a foundation of nature-based solutions, he said.

Guideposts for sustainability development exist around the world, but some of the most recognized are the 17 goals and 169 underpinning targets from the United Nations, he said.

In the United States, Lt. Col. (Ret.) Scott Spellmon, who served as the Corps’ 55th chief of engineers, released a command philosophy notice in 2023 that called for 70 percent beneficial use of dredged materials by volume by the year 2030. This was then codified into the Water Resources Development Act of 2024 in section 1130. Historically, Suedel said, the Corps has only reused 30 to 40 percent of dredged sediments beneficially. Examples include beach renourishment, island building, creating wetlands and reinforcing shorelines against erosion.

An example of beneficial sediment management he gave included the Horsehoe Bend Island project in the Lower Atchafalaya River south of Morgan City, La., where the Coast Guard realigned the channel, leading to sharp bends being eliminated, improving navigation safety and reducing long-term dredging requirements from once a year at the cost of $4 million to once every four to five years. That also resulted in carbon savings and reduced air pollution, he said.

The Biloxi Harbor Navigational Project deepened the navigation channel near Biloxi, Miss., to 12 feet but also restored the forests and eroded shoreline of Deer Island, which had been damaged by a hurricane, and created a 2.5-mile-long wave barrier that helps protect the city of Biloxi from future storms. That project also restored marsh, created terrestrial and aquatic habitat and generated long-term disposal capacity for sediments, he said.

At Bonanza Bar in the Ohio River, near Portsmouth, Ohio, dredged sediment has been mounded for more than 20 years with placement informed by historical navigation charts that indicated the bar location more than 50 years ago. Both hydraulic and mechanical dredging methods have reduced the frequency and cost of dredging the adjacent navigation channel and have provided recreational opportunities and restoration of habitat for native mussels.

PIANC offers a Working With Nature certification program. Projects that qualify between now and 2028 may be considered for PIANC’s Working With Nature Award, Suedel said. More information is available at www.pianc.org/working-with-nature.

Bank Protection

McKay spoke about riverbank protection methods. Before 1970, he said, engineers tried to control and dominate nature with hardened engineering using concrete, steel and straight lines.

“Over time that notion has eroded, and now we see a lot more emphasis on expanded project purposes and resilience of designs both in terms of natural systems but also built systems,” he said.

Conservation has evolved from building walls around nature to keep people away to increasingly acknowledging people as part of the landscape, McKay said.

Just as croissants, cookies and cake all use the same ingredients of butter, sugar, milk and eggs in varied amounts depending on what the baker would like to create, McKay said engineers can now use concrete, steel, rocks and vegetative solutions such as willow mattresses and root wads in varied amounts to prevent erosion.

Recently, McKay said, a PIANC working group produced three volumes of guidance on the design and implementation of features meant to address bank erosion, using global case study findings as a base of knowledge. The guide uses a seven-step process to recommend the most applicable measures of addressing erosion based in part on waterway types, severity of erosion, causes of erosion and project constraints, including budget limitations, he said.

“River engineering has a deep, deep history of aligning natural design processes with engineering design, and there’s often a rich history of guidance in these subjects,” McKay said. “However, as fields mature and as our body of knowledge grows, so, too, does our design approach, so there is always a need for new or emergent design methods, and programs like the Engineering With Nature program are investing in that appropriately.”