Lido Beach renourishment proposal lacks sufficient documentation, county’s draft peer review says

An engineering firm hired by Sarasota County says it cannot confidently accept the U.S. Army Corps of Engineers’ proposal for dredging Big Pass to renourish Lido Key beach

Big Sarasota Pass is the channel between Lido Key to the north and Siesta Key to the south. Image from Google Maps
Big Sarasota Pass is the channel between Lido Key to the north and Siesta Key to the south. Image from Google Maps

A 14-year compilation of studies and other materials representing the U.S. Army Corps of Engineers’ (COE) justification for its proposal to renourish Lido Key “[lacks] the supporting documentation necessary to confidently accept the conclusions,” says a draft peer review of the Lido Key Federal Shore Protection Project (Lido SPP), prepared by the Atkins engineering firm for Sarasota County.

Atkins, which has an office in Sarasota, was hired several months after the Sarasota County Commission voted to approve such a review.

The reports the county supplied to Atkins represent significant effort by the Army COE both to assess the feasibility of its Lido Key proposal and to analyze several design alternatives, the draft peer review executive summary points out. “However, the reports provided do not always include input data (and metadata) used for analysis,” the draft continues. “This leaves question and uncertainty with respect to data quality, repeatability, and geographic coverage as well as model calibration, verification and results.”

The Army COE has been working with the City of Sarasota on a 50-year plan to renourish the Lido Key Beach every five years, with the ebb shoal of Big Sarasota Pass designated as the principal sand source.

Big Pass never has been dredged, a fact Siesta Key residents have stressed since the Army COE project manager, Milan A. Mora, first presented the proposal in September 2013 to members of the Sarasota County Coastal Advisory Committee.

The draft also points to what it says appears to be conflicting information provided by the Army COE in reports, public meetings and a permit application to the Florida Department of Environmental Protection (FDEP) in regard to a number of the project’s elements, including dredge volumes, boundaries, depths and frequency. “The Corps reports do not conclude with a comprehensive presentation of results for the final selected design alternative,” the draft notes, adding, “A request to the Corps for clarification and additional information [has] been made by the reviewer through [Sarasota] County, but as of this report not received.”

The Sarasota News Leader did not receive a response to its request to the Army COE for comments by the deadline for this story.

A chart in the draft peer review lists the reports and studies Atkins analyzed for the review. Image courtesy Sarasota County
A chart in the draft peer review lists the reports and studies Atkins analyzed for the review. Image courtesy Sarasota County

Justin Bloom, executive director of Suncoast Waterkeeper, a nonprofit organization fighting the proposal to dredge Big Pass, did reply to the News Leader’s request for comments. In an email, he wrote, “I’ve reviewed the draft and am impressed,” adding, “[I]t validates many of our concerns and arguments. I definitely want to see the Board [of County Commissioners] take this up and will coordinate with (Save Our Siesta Sand 2) folks about requesting that commissioners set discussion on the agenda.”

The News Leader also contacted Rob Patten, a representative of Save Our Siesta Sand 2 (SOSS2) and the former environmental services director for Sarasota County. He told the News Leader in a Sept. 23 email that he had reviewed the draft report as well. As a result, Patten wrote, SOSS2 has been in contact with Laird Wreford, the county’s coastal resources manager, and has asked that the county send a copy of the report to the (FDEP), which is reviewing the permit application the Army COE submitted in March to undertake the project.

Additionally, Patten said SOSS2 has asked for a copy of the questions and comments county staff will provide Atkins to enable the firm to complete the peer review. Patten noted he had been in communication with Wreford, who was out of the office this week. Wreford told him, Patten added, that county staff had not had time to delve into the review at that point.

Finally, Patten wrote in his email to the News Leader, SOSS2 has asked Wreford to request, on behalf of the county, that the Army COE conduct an Environmental Impact Analysis and Statement (EIS) “as a result of the conclusions drawn by this report.”

An EIS is a more comprehensive review of a project than the Environmental Assessment the Army COE has undertaken.

The draft peer review was provided to the county on Sept. 21, Jason Bartolone, a county spokesman, told the News Leader. The original timeline called for the final peer review to be delivered by Sept. 20, Wreford said in an interview with the News Leader earlier this month. Nonetheless, the same period for county staff review and completion of the document applies as Wreford explained at that time, Bartolone confirmed: County staff has up to 10 days to review the draft report and provide comments and questions to Atkins. “Atkins then has seven days to revise and finalize the report, incorporating that feedback,” Bartolone wrote in a Sept. 22 email to the News Leader. “A public presentation to the Board of County Commissioners has not been scheduled at this time,” he added.

More concerns

The draft review’s executive summary references Army COE reports’ findings of the normal “downdrift” sand pattern on the west coast of Florida: Sand flows from Lido Key, across Big Pass and onto Siesta Key. “This natural transfer of sand maintains stable beach conditions on Siesta Key,” the draft continues. The Army COE’s proposal for the amount of sand to be dredged from the ebb shoal “is an order of magnitude greater than the estimated annual net southward transport of 118,200 cubic yards” at the south end of Lido Key, the report says.

On Sept. 4, when the Army COE responded to a request from the FDEP for more information to support the permit application, the Army COE cited 775,00 cubic yards as the amount of sand it proposed to remove from Big Pass for the first renourishment of Lido Key during its plan; that was down from about 1.3 million cubic yards in the federal agency’s earlier proposal.

A chart shows sediment amounts in the Lido Key system. Image courtesy Sarasota County
A chart shows sediment amounts in the Lido Key system. Image courtesy Sarasota County

Still, the draft peer review points out, “Atkins has concerns with respect to documentation of the accuracy and extent of the ebb shoal surveys. Much of the data (surveys) used to document the basis of the [Army COE proposal] was collected prior to 2002.” The draft also notes that the “latest shoreline change analyzed was dated 2000,” adding, “We recommend an update to the analysis of shoreline change, volume change and average erosion rates with more recent data … This effort would be prudent to [ensure] that conditions have not changed which may influence final project recommendations and design.”

The draft also says that in most projects involving the mining of ebb shoals, the dredge material is placed on downdrift beaches, “maintaining and augmenting the natural net flow of sand.”

Siesta Key Beach is a downdrift beach; Lido is not.

Further, the draft notes that the materials Atkins reviewed lacked the necessary documentation in regard to the amount of sediment in what it refers to as the “Lido Key cell and the regional system.”

The draft continues, “A representation of the sediment budget should be prepared that estimates the natural state of Lido Key erosion to clearly represent future concerns of Lido Key with and without nourishment projects.”

The draft peer review also questions the modeling and verification the Army COE used in its planning for the construction of two groins on Lido Key to help hold the renourished sand in place. “The reports do not document the potential for longshore currents at the groins to divert sand offshore and away from downdrift beaches,” it notes. “This could impair the natural transport to the ebb shoal at Big Sarasota Pass.”

Photos taken on Lido Key in June 2015 by Atkins staff show the eroded shoreline. Images courtesy Sarasota County
Photos taken on Lido Key in June 2015 by Atkins staff show the eroded shoreline. Images courtesy Sarasota County

Nonetheless, the draft says Atkins “intuitively feels that intermediate aspects of the project could be initiated as long as the long-term project is further studied …” It adds that if all other alternatives to protecting Lido Key structures threatened by erosion, including the use of sand dunes and emergency revetment, have been analyzed — and after further modeling has been completed and studied with results showing the groins would have no adverse impact on the natural downdrift sand system — the City of Sarasota should consider building the groins “and using an offshore sand source or a smaller amount of sand from [the] Big Sarasota Pass ebb shoal complex for nourishment.”

The executive summary does call for a “detailed plan of project monitoring covering the concerned beaches on Lido Key and Siesta Key, as well as the entire ebb shoal and accreting flood shoal area of Big Sarasota Pass ….”

As the draft review executive summary notes, Atkins was hired by the county specifically to analyze the Army COE’s plans in regard to their impact on Ted Sperling Park, owned by the county on South Lido Key, their impact on navigation in Big Pass, their impact on downdrift shorelines and the impact of a no-action alternative. As for the last item, the executive summary says simply that in the event no action were taken, Lido Key and Ted Sperling Park “would continue to experience erosion.”

The project itself

As detailed in the draft peer review, the Lido Key Federal Shore Protection Project is a federally authorized Hurricane and Storm Damage Reduction project proposed by the Army COE with the City of Sarasota as the local sponsor. The project was authorized by Congress in Section 364 of the Water Resources Development Act of 1999, which allows “federal participation for initial construction and periodic renourishment” of a 1.6-mile segment of Lido Key Beach for more than 50 years. Mora, the project manager for the Army COE, has said the federal government would pick up about 62 percent of the estimated $19 million cost. Alexandrea DavisShaw, the city engineer, has explained that Sarasota County Tourist Development Tax revenue and state grant funds would cover the rest of the expense. DavisShaw and Army COE spokeswoman Susan J. Jackson both told the News Leader this month that no federal money has been designated for the undertaking thus far.