Longboat adjusts sand-saving structure

In an effort to slow erosion, Longboat Key has added concrete teeth to one of its sand-protection structures.

By Alex Mahadevan
| 6:00 a.m. January 11, 2017

Cedars East owners Gill and Dave Hughes hope the groin adjustment slows the flow of sand on the north end.

Longboat Key
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Gill and Dave Hughes have been vacationing on Longboat Key for 25 years. That means they’ve seen about 25 variations of the north-end beach they frequent.

Although their grandchildren like playing on the 2-foot-tall sand canyon that has formed south of the south groin in front of the 360 North condominium complex, they wish the beach maintained more of the sand placed during last year’s $18 million renourishment.

“It’s a shame it disappears so fast,” said Gill Waters, a Wales native who owns a condo in Cedars East.

While Public Works Director Juan Florensa can’t say for sure if it will slow erosion significantly, his crews are shoring up one of the two sand-saving features, called groins.

How do you like your beach?

The town of Longboat Key will begin updating its comprehensive beach-management plan over the next year, following the placement of more than 700,000 cubic yards of sand along the island’s shores.

The document, which hasn’t been updated since 2008, quantifies the size and color of sand granules to be used in renourishment projects, how wide beaches should be and how the town should go about mining sand for such projects.

Town commissioners will vet those policies throughout meetings this year, and input from residents will be considered.

But, most important, the details in the plan will revolve around costs, which will likely soar to more than $20 million for the next renourishment.

“We all want sand, but what kind of sand?” Florensa said. “Are you willing to pay a premium to get that white, fine sand?”

“The thinking was, they were leaky,” he said of the structures, which stretch out across the Gulf of Mexico and contain strategic “teeth,” or baffles, to help slow the drift of sand. On the north end of the Key, sand naturally flows northward toward Beer Can Island and Longboat Pass, which is contrary to the normal flow for barrier islands on the gulf.

Last month, four public works employees spent a day hauling 100-pound concrete baffles to the North Shore Road beach access for placement. Because the groins are adjustable, there is a hole on each of their three levels to drill new pieces into place.

City staffers have installed 12 baffles, which were left over from the $2 million installation of the sand feature a year and a half ago, and plan to place between six and 12 more if weather permits. Choppy surf makes installation impossible, Florensa said.

The small-scale sand-saving project, for which the town paid roughly $2,000, comes more than a year after Town Commissioner Phill Younger criticized the then-new groins’ engineering — especially compared with the structure in front of the Islander condominium complex.

“Before one grain of sand from the dredging goes in,” he said at the time, “we ought to reassess this and make sure the issue of the baffling is addressed.”

The adjustment didn’t happen before the town mined 205,000 cubic yards of sand out of Longboat Pass to shore up north end beaches.

“I wasn’t happy with it when it happened,” he said in an interview with the Longboat Observer. “But they are taking steps to address the issue now, and I’m certainly happy about that.”