The Army Corps of Engineers responds to the state’s request for more details about its proposal to dredge Big Pass and build groins on Lido Key
In its Sept. 4 response to a request from the Florida Department of Environmental Protection (FDEP) for more information regarding its permit application to dredge Big Sarasota Pass to renourish Lido Key, the U.S. Army Corps of Engineers has reduced the amount of sand it proposes to add to the beach, documents show.
The March 2015 application from the Army Corps said the proposed Lido Key Hurricane and Storm Damage Reduction project would consist of the placement of approximately 950,000 cubic yards of sand along a 1.6-mile segment of Lido Key. The Sept. 4 project description cites “approximately 775,000 cubic yards of sand.”
The original estimate, presented to the Sarasota County Coastal Advisory Committee in September 2013, called for about 1.2 million cubic yards of sand, which would be dredged from Big Pass between Siesta and Lido keys.
The Army Corps’ Sept. 4 response to the FDEP continues to assert that “no adverse impacts to the coastal system and renewal of the [sand] resource” have been indicated in the modeling undertaken by the federal agency.
The permit the Army Corps is seeking would be for 15 years, the documents point out. However, Milan Mora, the project manager for the Army Corps, has proposed a plan spanning 50 years, with renourishment every five years. Mora also has told local government officials and community groups that the Army Corps proposes removing sand in alternate years from New Pass. However, both the original application to the FDEP and the response provided on Sept. 4 say, “New Pass may be used as a supplemental sand source, subject to the sand sharing agreement between Lido Key and Longboat Key.”
Three borrow areas have been identified in Big Pass. The revised project description of Sept. 4 also slightly adjusts the amounts in those areas. The March document notes about 300,000 cubic yards of “beach compatible material” in Area B, while the Sept. 4 description cites approximately 299,000 cubic yards. Further, the amount in Area C, which is located “within the ephemeral channel of Big Sarasota Pass,” is reported in the Sept. 4 documentation to contain about 975,000 cubic yards of sand, compared to the 985,000 figure in the March material.
A Sept. 4 letter to the FDEP from CB&I Coastal Planning & Engineering Inc. in Boca Raton, on behalf of the Army Corps, dealt with comments the state sent the federal agency in April, seeking more information. Among the responses, CB&I noted that the plan calls for dredging Borrow Areas B and C during the initial nourishment and that both areas “are anticipated to recharge at a rate such that they can be re-used for subsequent events.” However, the letter continues, if that rate of refilling “does not align with the nourishment cycle,” the plan calls for use of Borrow Area D.
The Army Corps is partnering with the City of Sarasota on the Lido Renourishment Project, which the federal officials have estimated at a cost of $19 million. Close to two-thirds of the funding would be needed from the federal government, Sarasota City Engineer Alexandrea DavisShaw and Mora have pointed out.
The material submitted to the FDEP on Sept. 4 says the project “is scheduled to commence in the fall/winter of 2015,” with an estimated 90 to 120 days of work, “including mobilization, construction and demobilization,” enabling the renourishment to be completed before the onset of the sea turtle nesting season, which begins May 1.
The Army Corps also proposes to construct two shore-perpendicular groins on Lido Key “at the south end of the fill area to stabilize beach fill on the southern end of Lido Key and lengthen the time required between sand placement events.”
The anticipated construction schedule for the groins is estimated to last from 90 to 105 days, the Sept. 4 material notes.
The Army Corps provided numerous documents to FDEP on Sept. 4, just two days after a spokeswoman for the Army Corps in its Jacksonville District Office told The Sarasota News Leader the material would be delivered to FDEP within two weeks. The FDEP’s response in April to the permit application is known as a Request for Additional Information (RAI). DavisShaw and Laird Wreford, coastal resources manager for Sarasota County, both told the News Leader last week that it is common for FDEP staff to issue a number of RAIs for a major project before it decides whether to issue or deny an application for a permit.
The Sept. 4 CB&I letter also responds to FDEP concerns about the impact of the proposed dredging on marine turtles. It says the “construction template has been revised” to reduce the potential effects, following discussion with FDEP staff and representatives of the Florida Fish and Wildlife Conservation Commission (FWC) and the U.S. Fish and Wildlife Service (FWS).
Regarding FDEP concerns about the potential impact on seagrasses within the proposed borrow areas, the letter notes, “No impacts to vegetation or the dune system are anticipated for this project at the northern taper.” Further, the letter points out, a 100-foot buffer has been placed around the seagrass mapped in September 2014 “to avoid impacts due to project-related turbidity and potential sloughing of materials.”
It also explains that the cuts in the vicinity of the seagrass will be thin, so only minor sloughing is expected, and it should be contained within the buffer area.
The letter also points to the submission to the FDEP on Sept. 4 of a biological monitoring plan, which will include a focus on the buffered seagrass within the borrow areas and on seagrass within 300 meters beyond the borrow area limits.
In regard to the proposed groins, the letter says “pier-type permeable adjustable groins (PAG’s) similar to the structures located on Longboat Key were not specifically considered” for the project, adding that the implementation of technology associated with PAGs “was not common at the time of the federal authorization for this project.” It continues, “However, the proposed rubblemound groin field is semi-permeable and can be adjusted by moving armor stone if deemed necessary.”
Responding to an FDEP query about the proposal to build a 200-foot-wide beach on Lido during each renourishment, the CB&I letter says the plan calls for that width because the beach is expected to erode to a width of 80 feet by the end of each five-year period between the placements of new sand.
Regarding a concern expressed by staff of the Division of Historical Resources (DHR) within the Florida Department of State, CB&I says 23 potentially significant historic resources identified in the vicinity of the borrow areas have been included on the revised permit drawings submitted on Sept. 4. The Army Corps is conducting further investigation of them “to determine if avoidance and/or buffering is required,” the letter adds, noting that the results will be provided to the FDEP after they become available.
Last week, Dee Ann Miller, who works in the FDEP Press Office, explained to the News Leader that after the state received the Army Corps’ response to the comments issued in April, the FDEP has 30 days to determine whether the application is complete or whether the department needs to issue another RAI. After an application has been deemed complete, she wrote in an email, the FDEP has up to 90 days to take final action — either issuing a Notice of Intent to Issue the permit or a Notice of Intent to Deny it. If anyone wishes to challenge the FDEP decision, Miller pointed out, the period for such action is within 14 days of the publication of the notice.