Seth Wilkinson of Wilkinson Ecological Design Inc. in Orleans was recently awarded a patent for an invention that could revolutionize the way eroding shorelines on Cape Cod and beyond are stabilized.
U.S. patent number 10,125,462 is for an “erosion control apparatus and methods of using and installing the apparatus.” Wilkinson submitted the patent for approval on Aug. 31, 2016 and it was approved last November. Three other related patents that Wilkinson submitted are still pending. The Wilkinson Reinforced Lift, which is its trade name, is constructed of anchored fiber rolls.
Erosion is a particularly urgent problem in Chatham. After the 1987 breakthrough of North Beach, the national spotlight focused on the town when houses along the eastern shoreline tumbled into the water as extreme erosion undercut them. Up to that time the traditional “brick and mortar” methods of protecting the shoreline were bulkheads, sea walls, and revetments, Wilkinson says. In fact, the sole solutions to erosion were “rock and retreat”—either erect a hard barrier or retreat away from the water.
The trouble with hard walls, particularly vertical ones, is that they tend to “reflect more energy,” Wilkinson said during a telephone interview last week. “The energy will have to go elsewhere, and it will erode the beach or the salt marsh in front of it.” In other words, hard engineering solutions increase erosion downstream. It is possible to protect one’s property only to erode one’s neighbor’s land.
After the destructive Perfect Storm of Halloween 1991, a doctorate student began studying ways to stabilize eroding shorelines without using hard structures. That is how Wilkinson’s firm, which is located at 28 Lots Hollow Rd., came to spend about a decade building on that knowledge. Wilkinson researched and developed a soft solution made of plants both living (beach grass) and dead (coconut fibers). It is a hybrid of sand bags and fiber rolls, combining the best attributes of each.
Wilkinson’s solution is “good in high-energy areas—plants don’t like to move,” he says. He describes the anchored fiber rolls as a “resilient way to retain the shoreline” because they absorb energy rather than reflecting it. This is known as the “Living Shoreline” approach endorsed by the National Oceanic and Atmospheric Administration (NOAA). The downside of soft engineering is, of course, that sandbags and earlier fiber rolls have not been sufficiently robust or structurally sound to prevent erosion. This, then, is the problem that Wilkinson believes he has solved.
After many years of perfecting the technology, including installing prototypes along Chatham’s eroding coastlines, Wilkinson felt he had something workable in 2016.
He turned toward patenting his device not because he was trying to corner the market on it, but because he wanted to establish design standards. Standards are clear for rock revetments, he says, but there are none for soft solutions. Other companies were copycatting his fiber rolls, but either getting them wrong or not installing them properly. And to have engineers oversee a project on-site every day is “cost prohibitive.” Therefore, the patent will serve to “control the integrity of the design.”
The fiber rolls, when installed properly and held in place with spaced duckbill anchors, have a “very good track record,” he says. They survived this winter in several locations north of the Chatham Fish Pier.
You may ask how the fiber rolls differ from sandbags, which Wilkinson dubs “sand-filled envelopes.” The answer is that they are as different as vegetarian and meat diets, Wilkinson says. While both have a coconut fiber component, the fiber roll is completely filled with coconut fiber. Anchors hold down the fiber rolls while waves pass over them. Plants such as beach grass can be planted in the fiber rolls, further anchoring them. Sandbags, in contrast, deflate over time. During a storm, the sand liquefies and slowly flows out and the bags cannot be repaired as they degrade. While sandbags last for five to seven years, the fiber rolls can last for 25 to 30 years. If the cables loosen in a violent storm, they can be tightened later.
Typically, each April around now the sand above the fiber rolls that was washed away during the winter is added back. Summertime beach goers will be unaware that the fiber rolls are underneath the sand. While a bad winter might give the beach grass growing from the rolls a “haircut,” Wilkinson says, the grass will grow back. The design provides a way to restore native plant communities on the beach. It’s a “stable and resilient way to restore the shoreline.”
Lower Cape conservation commissions have generally kept an open mind when it comes to the new technology presented by Wilkinson’s design. “They’ve done a good job listening and understanding,” he says. “There is a very significant difference between these approaches and the traditional approach.”
For more information visit www.wilkinsonecological.com.