The art of constructing Longboat’s beach

Editor & Publisher

Longboat Key’s sand will never stop washing away. Conversely, the town’s effort and ability to retain its 10 miles of Gulf front beach is a never-ending task if it wishes to preserve and enhance the property values of beach front homes as well as maintain a beach that residents and visitors can continue to enjoy.

To that end, the town is building two semi-permeable groins on the highly erosive north end of the Key and the first one was completed this week.

“It has been known for some time that groins are the only way for us to retain sand in that region,” Town Manager Dave Bullock told Longboat Key News.

And Bullock said the town’s historic program of layering sand in major renourishment projects along the entire length of the island is no longer viable. That is because the fact that there is less available sand of the quality, grain size, and color and it is further away from the key, has made the cost prohibitive.

When asked where the sand on the north end washes, Bullock said it mostly is transported into Longboat Key Pass on the north end and accumulates in several areas including the spit of sand that continues east off of Beer Can Island toward the bridge. Bullock says hundreds of thousands of cubic yards have moved in that area. He said the town recaptured some of that lost sand with a project in tandem with the West Coast Inland Navigation District when it was pumped back onto the beach last summer.

The overall strategy to mitigate the erosion on the north end is to slow the sand loss by using the two groins, to continue to dredge the channel and to negotiate moving the channel northward toward Anna Maria Island where it historically was located.

Bullock said the overall goal of the beach policy is to protect property and create a reasonable recreational beach factoring in anticipated erosion. He said the design strives to maintain 120 feet of recreational beach above the high water line.

“That is what you aim for, and nature immediately begins to redistribute the sand,” said Bullock.

Bullock said if the town did nothing, the island would quickly revert to its pre-1992 state and lose all recreational beach and would be vulnerable to storms such as the one that once washed away Gulf of Mexico Drive in the area known as Bayport. When asked if the town and beach managers are talking and planning or have accepted global warming and sea rise in their planning efforts, he said that the National Oceanic and Atmospheric Association and U.S. Army Corps of Engineers say that sea levels have been rising over the past century and it is prudent to take this into consideration in long range planning. Bullock added that the real threat to sea level rise will be on Longboat Key’s Gulf side because the dunes constantly move and grow and adjust to the Gulf of Mexico, while on the bay side it will simply be a loss of land.

For more information on the groin project, or on Longboat’s beach program, residents should call 316-1988 and speak with Public Works Director Juan Florensa.

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