Delve into 12: Erosion control

A $4.5 million emergency beach project deposited 133,000 cubic yards of sand along the north end last year. But that sand — deposited from just south of Broadway to just north of the North Shore Road beach access toward Beer Can Island — wasn’t meant to be a long-term solution to north-end beach erosion. The sand was intended to last approximately one year to help the beach survive the summer storm season while providing protection to the 360 North condominium. As of late October, approximately 77% of that sand remained, although some is now under water, where it still offers storm protection.
Much of the erosion is the result of the sand dynamics of the area, with sand along the northern part of the Key moving northward opposite the sand along most of the Gulf beaches, which typically moves toward the south.

In 2012, the Longboat Key Town Commission will discuss long-term solutions for north-end erosion.

One option is the construction of three groins — one terminal groin at the northern tip of Greer (aka Beer Can) Island along with two permeable adjustable groins at the north end, according to Coastal Planning & Engineering representatives, who presented in November the findings of the long-awaited $125,000 Longboat Pass Inlet Management Plan Study, which was jointly funded by the town and Manatee County.CP&E suggested that these structures, combined with the relocation of the Longboat Pass navigation channel, the extension of Anna Maria Island’s terminal groin and dredging of the Gulf Intracoastal Waterway would together work to solve ongoing erosion problems.

The commission hasn’t voted on the structures but reached consensus to begin immediately the Joint Coastal Permitting process for the groins, which typically takes a year. The commission will hold a joint meeting with the Manatee County Board of County Commissioners Feb. 14 to discuss the study. But, even if the commission does approve the structures, Longboat Key won’t see new groins in the next year. The town would likely receive permits mid-November. After obtaining permits, the town would have a three-month period of bid advertising and negotiation, followed by two months of contractor mobilization, meaning that the earliest start date would be April 2013 — if construction will be allowed during the sea turtle-nesting season.

The town’s next major beach renourishment project will also be discussed this year. Although the next project was originally scheduled for 2014, the project could happen sooner if the Oslo-based Port Dolphin LLC moves forward with plans to place a liquid natural-gas pipeline to the north of Anna Maria Island, which would run through a town sand source. The company agreed to help pay for the town’s removal of sand and its permitting costs prior to the pipeline placement. Port Dolphin deferred the project last March and has until March 2012 to defer the timeframe for another year, move forward with the project or cancel the project. The current deadline for the town’s removal of sand from this burrow area is June 2013.

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