Groin construction underway on Lido Key Beach

Rockbridge dredge, which removed sand from Big Pass, working on Manatee County’s Coquina Beach project

An engineering drawing in a Feb. 14, 2020 addendum to the USACE’s December 2019 Lido solicitation package shows the location of the two proposed groins on South Lido, near Ted Sperling Park. Image courtesy USACE

Groin construction is underway on Lido Key Beach, the U.S. Army Corps of Engineers (USACE) reported this week.

In a March 3 email, agency spokesman David Ruderman, who works out of the Jacksonville District Office, told The Sarasota News Leader that a crew had built an approximately 45-foot section of the first groin that will be used to try to hold sand in place between subsequent beach renourishment initiatives on the island.

Relaying information that he had learned during a USACE conference call about the Lido Key Hurricane and Storm Damage Reduction project, which took place on March 3, Ruderman wrote in an email that that initial segment of the groin contains “roughly 380-400 tons of stone so far …”

The first groin will be about 175 feet long, he noted.

The work was going well, he continued, with the company handling the project targeting March 10 for completion of the that groin.

“They project completing the second groin” the third or fourth week of April, Ruderman added.

That one will be 345 feet in length, based on the modified permit the Florida Department of Environmental Protection (FDEP) issued for the Lido project in April 2020.

Additionally, that revised FDEP permit specified that no groin construction “is authorized during the main part of the sea turtle nesting season (May 1 through October 31), and no groin construction equipment may be placed and/or stored on the beach.”

The permit also included the following condition: “During the portion of the nesting season (April 24 through April 30) and hatching season (November 1 through November 11) on-beach access to the construction site shall be restricted to the wet sand below [mean high water] to the maximum extent possible. Travel corridors on the beach to the [Mean High Water Line] MHWL will be delineated. Nests laid within the travel corridor that would impede traffic will be relocated per [FDEP] requirements … Nests laid in adjacent areas will be marked and avoided per the requirements … Staging areas for construction equipment shall be located off the beach to the maximum extent possible.”

This graphic shows the Sperling Park staging area (in blue). It was attached to an agreement between the county and the City of Sarasota regarding the county’s permission for the Lido contractor to use a portion of the park. Image courtesy Sarasota County

Cottrell Contracting Corp. of Chesapeake, Va., which won the $12,688,582 bid for the work on Lido, hired a subcontractor, Earth Tech Enterprises of Fort Myers, to construct the groins.

Structures called “marine mattresses” are an integral part of each groin, as explained in USACE documents. The December 2019 USACE solicitation for the Lido initiative called for stones in those mattresses to have “a nominal size between 1.5 and 3.5 inches.”

The document also noted the necessity of armor stones in the construction; the solicitation said those stones had to be “mostly uniform from 3,000 pounds to 5,000 pounds, with fifty percent (50%) of the stone greater than 4,000 pounds.”

The April 2020 FDEP permit explained that the groins would consist of armor stones “placed on 12-inch-thick foundation mats, lying on geotextile fabric.”

Each groin is to have a crest width of 9 feet and an elevation of 4 feet NAVD, which refers to the height above base flood elevation.

Further, the FDEP permit stipulated, “Only clean rock, which is substantially free of dust and debris, and which will remain stable in the surf zone, may be used for construction of the groins. Armor and bedding stone used in project shall be washed prior to being transported to the construction location to minimize turbidity.”

This is an engineering drawing in the December 2019 USACE solicitation package for the Lido project. It shows facets of the design, including armor stone. Image courtesy USACE

Turbidity refers to cloudiness in the water, which, if persistent, can harm sea life that needs sunlight to survive.

The stones have been stockpiled in a staging area in Ted Sperling Park on the southern end of Lido. Sarasota County, which owns the park, agreed to allow Cottrell to use it for the Lido undertaking, but Cottrell is required to return the park to its prior condition after the project has been completed.

Whither the Rockbridge?

Readers have commented recently to the News Leader about the fact that the Cottrell Contracting dredge the Rockbridge, which removed sand from Big Sarasota Pass for Lido Beach, has remained in the area.

When the News Leader asked Ruderman of the USACE about that this week, he responded that the Rockbridge is working on a Manatee County project in Longboat Pass, without USACE involvement.

On Feb. 5, the Rockbridge was stationary on the east side of Ted Sperling Park on Lido Key. Image courtesy of Michael Holderness

In December 2019, when the USACE issued a revised solicitation for the Lido undertaking, Trisston Brown, chief of the Florida Projects Section for the Water Resources Branch of the USACE in Jacksonville, told the News Leader that the federal agency hoped to have more success than it did with its original bid in 2019. The first attempt resulted in responses that the USACE deemed unreasonably high, he noted.

The second solicitation, Brown explained, would “allow for an unconstrained construction start time” and would give companies the opportunity to bid on a Manatee County project, as well.

Based on FDEP documents and information on the Manatee County website, the Rockbridge has traveled up to Longboat Pass to dredge sand for a Coquina Beach renourishment project.

A graphic provided by shows the location of the Rockbridge (marked by the shaded circle) in Longboat Pass on March 4. Image from

Issued on Oct. 9, 2019, the FDEP permit for the Coquina Beach undertaking pointed out that Anna Maria Island “experiences historic chronic beach erosion.” As a result, the permit continued, “[T]wo established beach nourishment projects are maintained on the island: the federally authorized Central Beach Renourishment Project … and the locally sponsored Coquina Beach Nourishment Project …”

“At the request of the [Manatee] County,” the permit added, “the Corps plans to incorporate the Coquina Beach project into the bidding of the Central Beach project.”

The Manatee County website says that the county awarded the Coquina Beach initiative to Cottrell Contracting, which “started dredging on Thursday, Feb. 25.”

“The Coquina Beach Storm Damage Restoration project consists of the hydraulic placement of 74,805 cubic yards of fill on Coquina Beach, located immediately north of Longboat Pass on the southern end of Anna Maria Island in Manatee County. The project area extends approximately 7,747 feet from south of Bridge Street in Bradenton Beach to the southern end of the island at Longboat Pass,” the website explains.

The construction is expected to continue through mid-May, the website noted.