The idea is rather simple at its core — put an incredible amount of sand on the coastline of an island and allow the sand-sharing system to do what comes naturally. It’s more than just beach renourishment — it’s meant to save part of the island from disappearing altogether.
That’s the intention behind an idea in development on Jekyll Island. The north end of the island is eroding away into the St. Simons Sound, from the tip down through Driftwood Beach. The rock revetment repair on the northeastern part of the island is nearly done, and will do its job, but there’s a space of virtually unused beach between it and Driftwood that’s not that inviting for man or beast. This is where, Applied Technology & Management engineer Heath Hansell said, the “sand motor” can go in.
Hansell presented the idea as the Georgia Environmental Conference drew to a close Friday. He said this space of relatively unused beach is a derelict, historically altered shoreline left over from the original revetment built following Hurricane Dora. And there’s evidence sand from this area, north, is flowing into the sound.
“We’re losing the battle, moving here north,” Hansell said. “High erosion rates, we’re losing ecosystems and habitats. Infrastructure — there is a main, arterial road right behind here, and every year that road is getting closer to the waves.
“What we really want to do is try to figure out a way to have a sustainable transitional area between … we have a developed shoreline, and we need protection for that shoreline, but then we’ve also got this natural shoreline right next to it that’s eroding, and we want to do something about it.”
He said there are known man-made and natural issues at play, but they want to use a holistic approach and work with nature to address the problem.
“We would love to have a beach there — beaches provide recreation, habitat, coastal storm protection, all of these benefits — and right now we don’t…,” Hansell said.
Enter the sand motor, an idea first conceived and put into practice in the Netherlands. According to a 2017 NPR story, the original sand motor cost $81 million and used around 28 million cubic yards of dredged sand. The idea is for waves to move the sand into protective areas six miles along the coast over a period of 20 years.
“It creates wider beaches, wider beaches stimulate natural formation of dunes, and the dunes will get bigger,” Jasper Fiselier, an environmental engineer with Royal HaskoningDHV, said to NPR. “That will give more safety in the end.”
Hansell described the look as like a shoal that would also have a life of around 20 years.
“It’s basically a natural shoal attachment sort of feature,” Hansell said. “Sand naturally wants to jump across inlets from island to island, moving down. And when one of these large jumps occurs, it’ll attach to the beach next to it, and look similar to this. What it does, is attaches to the beach and spreads out naturally, and nourishes all the beaches around it for however long it takes for that to erode, and hopefully by the time it does, we there’s another shoal attachment.”
With the recent success of the Jekyll Creek dredging and marsh pilot project, Hansell said if this idea goes forward, the hope is to bring in a large number of partners to work on the project.
“We want to be open and collaborative, and we want help from these people and their input the whole time we go through this,” Hansell said.
Jekyll Island Authority Conservation Director Ben Carswell called it a vision in search of a supportive, collaborative team.