Live Green: Living Shorelines on Thompson Island!

SUSSEX COUNTY, De – Nearly 400 wave attenuation devices have been put into place in order to protect Thompson Island.

Thompson Island has been depleting. As a solution, The Delaware Center for Inland Bays and DNREC have partnered to install living shorelines to prevent erosion. So far, they have completed phase one, with three more phases to go.

“It will wrap around. But there will be a gap here. To let animals through,” Project Manager, Bob Collins said. “It was 1.1 million, something like that. So, the next phase is going to be similar, if not more.”

The devices are three and a half feet tall and weigh 2,200 pounds or more. They’re made of cement and water for binding, and rock and sand for filtering, and the planning process takes between 2-4 years. 

“There’s a lot of design. There’s, like, convincing sometimes there’s a lot of permitting. Even though this has been around for 20 years, technologies have been around the world, there’s only been a handful of projects up in the northeast that is done,” Natural Resources manager, Doug Janiec explained. “There’s actually no storm that’s going to move these. So, these are going to be here until for generations.” 

The very first installment was in Florida, and their structure has helped replenish shorelines. The science behind their pyramid shape and alternating pattern diminishes oncoming wave energy instead of deflecting, unlike conventional breakwaters, which are more harmful. Conventional breakwaters cause scouring and are disruptive to marine life. Living shorelines however, are made of recycled material.

“The idea is here is let the wave energy go through the structures, and it breaks down the energy or dampens into a form that’s nondestructive,” Janiec explained. “It also allows transports and sediments to fall out from the waste behind there for the beach. That beach will start rebuilding naturally now.”

The beach and the devices will look different in a few years. There will be more of a sandy shoreline, and now, the devices are cement pyramids. However, in a few years, they will become a reef, providing habitat for marine life such as oysters, barnacles and crabs to use as ledges for feeding. The devices also poke out of the water, and this gives birds a place to perch.

To learn more about the wave attenuation devices or living shorelines, visit the inland bays website or DNREC.