PLACEMENT: Consent
TITLE:
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REQUEST TO EXECUTE THE COOPERATION AGREEMENT WITH THE ARMY CORPS OF ENGINEERS FOR THE HUTCHINSON ISLAND SHORE PROTECTION PROJECT
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EXECUTIVE SUMMARY:
executive summary
The Board is requested to review and approve the Cooperation Agreement with the US Army Corps of Engineers for the upcoming Hutchinson Island Shore Protection Project.
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DEPARTMENT: Public Works
PREPARED BY: Name: Jessica Garland
Title: Coastal Program Manager
REQUESTED BY: US Army Corps of Engineers
PRESET:
PROCEDURES: None
BACKGROUND/RELATED STRATEGIC GOAL:
1. Agreement/Contract drafted by: United States Army Corps of Engineers (USACE)
2. Parties to the Agreement/Contract: Martin County & the United States Army Corps of Engineers
3. Purpose of the Agreement/Contract: The USACE has received $11,400,000 in Hurricane Nicole response funds for the Hutchinson Island Shore Protection Project (SPP). These funds will be used by the Corps to repair damages caused by Hurricane Nicole, along with addressing routine erosion since the project’s original construction in 2018. Project bidding is scheduled for August 2025.
4. New/Renewal/Modified: New
5. Duration: The term of the agreement will conclude upon construction completion.
6. Benefits to Martin County: The project will include renourishment of the full beach and dune cross-sectional template with approximately 309,000 cubic yards (CY) of sand from the project’s approved offshore borrow area.
7. Cost to Martin County: There is no local share required for execution of the agreement.
This cyclic beach renourishment project, authorized under Section 101(a)(8) of the Water Resources Development Act of 1990 (PL 101-640) following the Chief of Engineers' report dated November 20, 1989, encompasses 4.0 miles of shorefront extending southward from the St. Lucie County line to near the limit of Stuart Public Park (R-1 to R-25). The authorized plan involves beach nourishment with a construction template that includes a 90-foot-wide beach berm at 6.5 ft NAVD88 and a 1V:10H foreshore slope. This construction berm incorporates a 35-foot-wide authorized design berm plus advanced nourishment, tapering from FDEP reference monument R-2 south to R-24 and extending approximately 900 feet north and south to R-1 and R-25. Additionally, the construction included a 20-foot-wide dune feature at elevation 11.0 ft NAVD88.
Since the project's authorization, six construction projects have been completed, including two partial projects in 2001 and 2002, and post-hurricane recovery projects in 2005, 2013, and 2018. The initial four projects utilized material from Gilbert Shoal, located about 1.2 miles off the southern project limit, with direct pumping to the shore. More recent projects sourced sand from a new borrow site on St. Lucie Shoal, approximately 7 miles offshore and just north of the project's northern boundary, employing a hopper for transport and pipelines extending offshore at both the north and south ends.
In November 2022, Hurricane Nicole caused an estimated erosion of 248,000 cubic yards (CY) within the project area. Accounting for normal sand migration and storm erosion, an estimated 309,000 CY is needed to restore the full beach renourishment construction template. The proposed emergency work to rebuild this template, at a federal expense of $11,400,000, will involve renourishing the full construction template with approximately 309,000 CY of sand from the designated offshore borrow area. It is important to note that the final contract quantity of sand may vary from this estimate due to changes in the beach profile between the post-storm survey and the actual construction.
Furthermore, the project area was impacted by both Hurricanes Ian and Nicole in November 2022, with Hurricane Nicole resulting in a net erosion of 77,157 CY across the project. While annual monitoring reports suggest minor accretion due to longshore dispersion of fill south of the 2018 placement area and at the northern extent, the storm-induced erosion has outweighed these benefits. Evidence also indicates seaward cross-shore sediment movement; however, significant erosion of the upper berm and dune throughout the central and southern portions of the project area suggests that natural post-storm beach recovery is unlikely due to sediment displacement beyond 20-feet-below NAVD88. The specific design details for this renourishment effort will be developed during the Pre-Construction Engineering and Design (PED) phase.
ISSUES:
None
LEGAL SUFFICIENCY REVIEW:
This item has been reviewed for legal sufficiency to determine whether it is consistent with applicable law, has identified and addressed legal risks, and has developed strategies for legal defensibility.
RECOMMENDED ACTION:
RECOMMENDATION
Move that the Board authorize the Chair to execute the Cooperation Agreement between the USACE and Martin County for the Rehabilitation of a Federal Hurricane/Shore Protection Project.
ALTERNATIVE RECOMMENDATIONS
Pull this item from the Consent Agenda and direct staff accordingly.
FISCAL IMPACT:
RECOMMENDATION
None
ALTERNATIVE RECOMMENDATIONS
None
DOCUMENT(S) REQUIRING ACTION:
☐Budget Transfer / Amendment ☐ Chair Letter ☒Contract / Agreement
☐Grant / Application ☐Notice ☐Ordinance ☐Resolution
☐Other:
This document may be reproduced upon request in an alternative format by contacting the County ADA Coordinator (772) 320-3131, the County Administration Office (772) 288-5400, Florida Relay 711, or by completing our accessibility feedback form at www.martin.fl.us/accessibility-feedback <http://www.martin.fl.us/accessibility-feedback>.