US Army Corps of Engineers
Jacksonville District Website

Lido Key shore protection public meetings set for July 23, Comments welcome on draft study, Big Sarasota Pass sediment mining alternatives

Published July 18, 2014
Beach erosion on Lido Key

Beach erosion on Lido Key

JACKSONVILLE, Fla. – The U.S. Army Corps of Engineers, Jacksonville District, invites the public to provide comments on issues regarding the Lido Key Hurricane and Storm Damage Reduction Project.

The Corps and the City of Sarasota will host two meetings July 23 at the Sarasota City Hall, 1565 1st Street in Sarasota. An afternoon meeting begins at 2 p.m. in the SRQ Media Center and an evening meeting begins at 6 p.m. in the Commission Chambers.
 
The meeting agenda starts with a sign-in and the availability of subject matter experts to discuss project information and answer individuals’ questions prior to the formal presentations, which will begin at 2:30 and 6:30 p.m., respectively. Following the presentation, the Corps will invite meeting attendees to publically ask questions and provide comments. Subject matter experts will also be available following the formal portion of the meeting.
            
In addition, the public and agencies can also send written comments to aubree.g.hershorin@usace.army.mil or:

U.S. Army Corps of Engineers
Jacksonville District
Planning and Policy Division, Environmental Branch
Attn: Aubree Hershorin, Ph.D.
P.O. Box 4970
Jacksonville, FL 32232-0019 

The Corps will address submitted remarks and questions at the meeting and also in the draft National Environmental Policy Act document, which it anticipates making available for further public comment in late 2014.

The City of Sarasota requested federal assistance with shore erosion more than a decade ago, and Congress directed the Corps of Engineers to construct the Lido Key Project as part of the Sarasota County Hurricane and Storm Reduction Project. The Corps conducted an Environmental Assessment in 2002, with a Feasibility Report Addendum in 2004. The Corps report describes a preferred plan with nourishment of an 80-foot-wide beach berm on 1.56 miles of shoreline and a groin field at the southern limits of the project. The nourishment would require sand placement at approximate five-year intervals for 50 years.
 
The offshore sand sources evaluated in the report for Lido Key did not contain sand that meets current Florida Department of Environmental Protection’s criteria.  A subsequent sand search was conducted to identify other sources; however, no compatible offshore sand was identified within an economically feasible distance of Lido Key. The high cost associated with bringing in offshore, compatible sand would have far outweighed the federal project’s benefits and negated federal interest in the project.
 
Concurrent with this sand search, Sarasota County drafted the 2008 Comprehensive Inlet Management Program: Big Pass & New Pass, which identified potential alternatives for dredging these two inlets.
 
The Corps recently performed a study that evaluated whether future excavation of the ebb shoal at Big Sarasota Pass (BSP) for use on Lido Key using the Inlet Management Program alternatives would significantly alter the ebb shoal morphology or local/regional sediment transport patterns in a way that would cause adverse impacts to adjacent beaches.  The draft report, Study of Big Sarasota Pass Sediment Mining Alternatives for Sarasota County, Lido Key Federal Shore Protection Project, was released in June 2014 and is available at www.saj.usace.army.mil/About/DivisionsOffices/Planning/Environmental Branch/EnvironmentalDocuments.aspx#Sarasota.
   
Generally, the report states that the volume and shape of the BSP ebb shoal, which historically averaged about 21 million cubic yards (MCY), has changed little since 1883. The size of the ebb shoal has increased in the recent decade due to sand drifting off of Lido Beach, which was renourished multiple times since 1964. The present volume of the BSP ebb shoal is 23.3 MCY and the Lido Key Project anticipates using approximately 1.3 MCY of this material.  Engineering analysis found that it’s possible to remove this quantity of sediment from the ebb shoal without changing the shoal’s overall shape and determined the project would mine about 6 percent of the entire shoal volume.
 
Coastal modeling results show it’s possible to mine the ebb shoal without affecting sediment transport to adjacent beaches such as Siesta Key.  Engineers used a state of the art model that can reproduce near-shore sediment dynamics at tidal inlets.  Their analysis shows that a dredging configuration can be constructed so it does not induce undesirable change at the ebb shoal, does not increase wave energy at the shoreline, and does not affect navigation.  Modeling and analysis further show that the expected annual sediment bypassing rates will not decrease from the present rate.
 
Engineers also investigated dredging configurations that may potentially alleviate some negative impacts caused by development activities in the 1920s through mid-century, and relieve pressure from the main ebb channel on the interior north shoreline of Siesta Key.
 
“One of our key objectives throughout this process was to keep information transparent so our partners and the public were well-informed and engaged. These upcoming public meetings are part of this process, so we can present new information, answer questions and receive comments,” said Corps project manager Millan Mora.


Contact
Susan Jackson
904-232-1630
susan.j.jackson@usace.army.mil
904-232-2237 (fax)

Release no. 14-039