VKB Town Hall Presentation - 8/20/2020

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VKB Resilience General Obligation Bond Protecting the Village’s Beaches and Shoreline Town Hall #2 August 20, 2020

Upcoming GO Bond Town Halls: ✓ August 20, 2020 September 3, 2020 September 17, 2020

For Dial-in Instructions: https://keybiscayne.fl.gov/clientuploads/COVID19/Virtual_Public_Meeting_Instructions.pdf

(Source: Long Range Beach Nourishment Plan, CSI 1997)

Nearshore / Offshore Bathymetry, March 2017

Physical factors that drive erosion: • Depth of bedrock • Depth of water • Bottom characteristics 1. Hard, high relief (reefs) 2. Hard, low relief (rocky) 3. Soft, sandy 4. Soft, vegetated (seagrass) • Wind intensity/direction • Wave intensity/direction • Tidal currents intensity/direction

Bedrock Elevation


Shoreline Protection is about managing ENERGY/EROSION

Nearshore and Offshore Hardbottom Coverage Natural offshore reefs (hardbottom) are first line of defense for shoreline protection. Hardbottom habitat effective dissipator of wave energy. Seagrass beds provide stability to otherwise soft and shifting sediments

General direction of longshore sediment transport

As sea level rises and storms intensify, energy onto the beach increases and so does erosion

VKB Beach Management Feasibility Study, 2018

Directional wave rose along 2m contour (-6.56 ft)



(Source: Long Range Beach Nourishment Plan, CSI 1997) 1904 – Government Cut dredged through southern extent of barrier island (aka South Miami Beach) forming Fisher Island Changes to tidal currents through cuts have significant effects on sand movement

Influence of Government Cut on Historic Shorelines


Summary of Historical Beach Nourishment Events 1969 – USACE Beach Fill, offshore sand source 1987 – USACE Beach Fill, offshore sand source + reconstruction/extension of groin at lighthouse. Prior to 1998, projects were managed by the U.S. Army Corps of Engineers with MiamiDade County as the local sponsor. The Village has managed and implemented projects between 1998-2017. 2002, 2008, 2012, 2017 – Non-federal Beach Fill, offshore sand source

Future will Require Continual Nourishment Events (2021, 23, 26………)

St. Lucie County, FL FPL Reef/Breakwater Project


Maiden Island, Antigua

Reduce beach erosion associated with cooling canal for nuclear power plant, in conjunction with dune restoration.

Colonized Reef Ball Reef Ball Foundation, Bradenton, FL

1,200 Reef Balls were used to create

the world’s largest fringing breakwater reef system

Considering Offshore Structure / Artificial Reef to Reduce Shoreline Erosion

Sunny Isles Beach, FL

Village of Key Biscayne

discontinuous submerged structure

Bahamar Beach, Bahamas


(VKB Beach Management Feasibility Study, 2018)

Challenges at a Glance

increased deposition

increased erosion

Impacts to sediment transport Impacts to water circulation Habitat impacts to seagrass Creating new hard bottom habitat Permitting (USACE, FDEP, DERM)9

Update on Inclusion of VKB into USACE Feasibility Study 1. USACE is proceeding with feasibility study for Miami-Dade County without Key Biscayne 2. A Waiver has been submitted and processed by the USACE Jaxs Office and forwarded to USACE Headquarters for approval and inclusion of VKB into feasibility study 3. Rep. Donna Shalala submitted letter of support to ASA requesting approval, co-signed by Reps. Diaz-Balart, Mucarsel-Powell, Wasserman Schultz 4. Waiver is due to be reviewed by Assistant Secretary of the Army (ASA) for approval

IF KEY BISCAYNE INCLUDED IN FEASIBILITY STUDY A. VKB will work with USACE JAXS to provide data to support a federal project (aka. Tentatively Selected Plan) B. Once TSP developed, it is submitted to USACE Headquarters for review and release to Chief of Engineers for further evaluation/refinement C. Once Chief of Engineers signs off on the TSP, USACE makes recommendation to Congress for project funding (2022 first opportunity to secure an authorization, funds in FY23)

What If……………….. What if Not ? either way it is a long multi-year process

✓ IF the project is authorized in Water Resources Development Act (WRDA) 2022, the first construction phase could be funded in FY 2023 assuming the Corps allows the new project to begin before the expiration of the current Dade County authorization at the end of 2024.

✓ IF included in this complex process, 65% federal funding, 35% other funds (local, state grants etc….)

Congressional authorization process and the congressional appropriations process will require continuous communication and work with the pertinent congressional committees of jurisdiction, the Village’s congressional delegation, and the USACE.

G.O. Bond at a Glance GOB Programs GOB Projects

Mitigating the Effects of Sea Level Rise and Flooding

Total Cost

GOB Program



Roadway Improvements/Complete Streets South

Series 1

Series 2


Roadway Improvements/Complete Streets North

$13,000,000 $64,550,000


2023 Beach Nourishment & Breakwater Analysis


2026 Beach Nourishment & Breakwater Analysis Cont.+ Permitting


Breakwater Construction


Breakwater Mitigation

Hardening Infrastructure to the Effects of Hurricanes

Series 4


Roadway Improvements/Complete Streets Central

Protecting the Village's Beaches and Shoreline

Series 3




Hardening & Undergrounding Phase 1 (South)

$9,000,000 $11,500,000

Hardening & Undergrounding Phase 2 (Central)


Hardening & Undergrounding Phase 3 (North)


Hardening & Undergrounding Phase 4 (Mashta) $153,750,000






Shoreline Protection Estimated Budget

Sub-Total =

$3.4 MM Truck-haul @50,000 Cubic Yards $10.3MM Offshore Breakwater hard cost $2.1MM soft cost $7.5 MM Seagrass Mitigation $23.3MM (GOB)

Over the next 50 years, assume 6 nourishment events $3.4MM = $21.25MM Over the next 50 years, assume 4 seagrass mitigation events $5MM = $20MM Sub-Total =

$41.25MM (other funding sources)

Grand Total =



QUESTIONS Email: VKBresilience@keybiscayne.fl.gov

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