Firm gets green light on erosion project
The city of Sanibel moved forward on the full design, engineering and permitting for the emergency shore-protection project south of Blind Pass on Sanibel’s north end, adjacent to Sanibel-Captiva Road.
At its May 7 meeting, the Sanibel City Council voted 5-0 to authorize the city manager to enter into negotiations with Humiston & Moore Engineers to address the erosion situation. Earlier this year, the city had hired the coastal engineering firm to look at the area near Pine Avenue and Castaways Beach and Bay Cottages and to come up with some options to better protect the nearby road and properties.
According to documents prepared by the firm and submitted to the council members, Lee County installed a rock revetment in 1992 along 200 feet of the roadway to provide limited storm protection.
“Recent storms and cold fronts in 2018 and 2019 have resulted in increased sand loss and vulnerability along the same section of roadway,” the firm reported. “It is the intent of the city to design improved protection along this section of roadway and extend the protection further north and south of the existing buried revetment to provide high frequency storm protection to the most vulnerable 400-foot section of the evacuation route for the island of Captiva and the north end of Sanibel.”
It added that the project’s conceptual plans were prepared and reviewed with city staff, based on a survey completed in April, and preliminary pre-application meetings have been held with the Florida Department of Environmental Protection and Florida Fish and Wildlife Conservation Commission.
“The concept plan involves the addition of a larger armor stone layer along the existing buried revetment and installation of a steel sheetpile wall with a concrete cap upland of the revetment, along the edge of the right-of-way, for the approximate 400-foot section of vulnerable roadway,” the firm reported. “Additional rock will be included for toe-scour protection north and south of the existing revetment seaward of the new wall and tapering of the rock further landward.”
“The project is intended as a last line of defense to border and protect the existing road and allow for potential future improvements to the roadway,” it continued. “With the next phase of beach restoration currently scheduled for the winter of 2020-21, without additional shore protection improvements, the roadway would remain vulnerable and subjected to overtopping and potential damage from high frequency storm events.”
The firm outlined four tasks for it to execute the project: site data verification, permit plans and regulatory coordination; preparation of technical specifications, bid schedule and opinion of probable costs; bid phase services; and construction phase services. It estimated its cost at about $35,704.
“This will necessitate coordination with sea turtle monitoring, securing the necessary regulatory permits and selection of a contractor,” the firm reported.
Prior to the vote, Vice Mayor Mick Denham asked what the council could do to support staff and help move the project along. Natural Resources Director James Evans explained that an approving vote would enable Humiston & Moore to proceed with the project’s full design, engineering and permitting.
“Our plan is to get this permitted as quickly as possible,” he added.
Evans previously said he hoped to have the project well under way before October.
The beach naturally accumulates sand in the summer and loses it in the winter because of the winds. If the project is finished before winter, sand can accumulate on top of the new sand the city puts down.
He also previously noted that the biggest variable for the project will be permitting.