Cajun ingenuity, combined with Ragin’ Cajun® research, may help solve the problem of coastal erosion. Louisiana’s wetlands are in danger, with land slipping away at a rate that’s equivalent to the loss of a football field an hour, according to the United States Geological Survey.
Webster Pierce, a 71-year-old inventor from Cut Off, La., a coastal community in Lafourche Parish, said he doesn’t have to rely on data to know there’s a problem. Over the years, he’s seen the marshes where he used to hunt and fish disappear, replaced by open water.
He got the idea for his Wave Robber, a wave suppression/sediment collection system, from another coastal restoration strategy: placing discarded Christmas trees at the shoreline to help reduce land loss.
“It works for a while. But when the trees decompose, erosion starts all over again. I was looking for a better solution,” he told La Louisiane. Pierce patented the Wave Robber and also holds patents on a blanket designed to put out kitchen fires, a tool that chips barnacles off pipelines and an electric jar opener.
The Wave Robber resembles a small set of stairs with pipes running through them. Anchored to the seafloor, it breaks up waves, absorbing their energy. The interior pipes “rob” the waves of sediment and redeposit it behind the device.
A University of Louisiana at Lafayette research team, led by Dr. Daniel Gang, is testing it in the laboratory and in the field. The University’s goals are to refine the design of the Wave Robber and to evaluate its commercial viability.
In the Hydraulics Lab in Madison Hall, three scale models of the invention are at work in a 1,000-gallon tank. A paddle, driven by a pulley and motor, creates waves, pushing water and sand toward the test units. Weirs, placed between the devices, allow the water to flow back toward the wave generator.
A full-size version was installed in Cut Off in November. Since then, it has collected about one inch of sediment.
“The bottom line is, it works,” said Gang.
Scott LeBlanc, a graduate student in civil engineering, is responsible for maintaining the testing sites and collecting and analyzing data. He earned a bachelor’s degree in civil engineering in May 2011 at the University and plans to graduate again in December. The Wave Robber is the subject of his master’s thesis.
One of the questions LeBlanc has studied is related to the unit’s design. How steep should the slope of the “stairs” be for the Wave Robber to be effective and affordable to mass produce?
Graduate students Rifat Alam, Nicholas Baudoin and Hanlong Ren; Nicholas McCoy, a senior; and Roshan Sharma, a junior; are other civil engineering students who have been involved in the project. Andrew Omondi, ’12, who earned a bachelor’s degree in civil engineering, also participated in the research.
Pierce’s design has advantages over a common strategy that’s employed in coastal restoration: creating artificial barriers with rocks. Those projects are expensive and can have a negative impact on the environments they’re designed to protect. When water flow is restricted, organic material can’t be delivered to the shore. And wildlife, including fish, may be cut off from the wetlands that support them.
Wave Robbers are lightweight, so they can be easily deployed by boat, even in shallow water. Pierce plans to manufacture them using durable, UV-resistant plastic. They are expected to last up to 20 years.
“The beauty of these things is that they can be used over and over again. When the shoreline is built up in one area, they can be moved to another location where they are needed,” Pierce said.
Pierce holds a bachelor’s degree in science education and a master’s degree in education, both from Nicholls State University. For eight years, he was a junior high and high school science teacher. “I’ve always had an interest in science, but I couldn’t afford to support my family on a teacher’s salary,” he said.
Pierce became general manager of the South Lafourche Levee District, where he observed how the levees work and their limitations. “Levees aren’t enough. In a hurricane, we need land outside the levees to withstand the storm surge.”
By 2009, he was testing a homemade version of the Wave Robber in his back yard. He used a wave tank — a trough made of fiberglass — and a plywood wave suppression/sediment collection device. He created waves with parts from an old washing machine. The machine’s agitator, driven by its gear box, pushed water back and forth in the tank.
That same year, Pierce reached out to Dr. Tommy Michot and Dr. Donald Hayes, experts at UL Lafayette’s Institute for Coastal Ecology and Engineering.
They helped Pierce by securing a three-year, $180,000 grant from the Louisiana Board of Regents in 2011. Pierce’s company, Pierce Industries LLC, contributed an additional $45,000 to the project and the University provided $42,200.
Hayes, who is now a faculty member at the University of Nevada, Las Vegas, also referred Pierce to the Louisiana Small Business Development Center. When Hayes left UL Lafayette in August 2011, Gang became the principal investigator for the project.
Funding was renewed this year, with another three-year commitment: $188,275 from the Board of Regents, $55,600 from Pierce Industries and $48,170 from the University.
His project got a boost in March, when he received a $50,000 prize during New Orleans’ Entrepreneur Week, an initiative aimed at connecting entrepreneurs and investors. He was the winner of the Water Challenge, a business-pitch competition focused on water issues.
The next step for the Wave Robber is a demonstration project, organized by the National Resources Conservation Service. Tom Cousté, an engineer with JESCO Environmental and Geotechnical Services of Jennings, La., said UL Lafayette’s work helped convince federal officials that the project was worthy of attention.
The device is expected to be deployed on the shoreline of Shark Island in Vermilion Bay in August. JESCO is handling the project.
In addition to JESCO, and the UL Lafayette team, Pierce has also continued to work with Hayes. Other Louisiana universities have contributed to the project as well. Students at Loyola University New Orleans are creating a marketing plan, Nicholls State University has provided business development support and Louisiana State University has conducted site surveys and provided consultations.
“It’s something I can’t do on my own but it’s definitely worth doing,” said Pierce.