BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District SARASOTA COUNTY – LIDO KEY HURRICANE & STORM DAMAGE REDUCTION PROJECT City of Sarasota Sarasota County US Army Corps of Engineers 22 October 2013 Sarasota, Florida Presented by: Milan A. Mora, P.E. Jason Engle, P.E. James LaGrone Kathleen McConnell BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | JACKSONVILLE DISTRICT Information Presentation BOCC Joint Meeting

BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District OVERVIEW – PROJECT SCOPE  Authorized WRDA 1999 Authority was contingent on a feasibility assessment of the project Feasibility Study with Environmental Assessment (amended April 2004) determined that project was technically sound, environmentally acceptable and economically justified. BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District

BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District OVERVIEW – PROJECT FEATURES BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District 3 D2 C B Project Scope  Project Length (ft) = 8,280 (R-35 to R43)  Design berm elevation (ft) = +5 NGVD  Approximately 460,000 cy of design and 615,000 cy of advance material (1,075,000 cy for Initial Const)  Three groins along the southern portion  Borrow Areas: Big Sarasota Pass (BSP) & New Pass  5-year nourishment interval over 50-year life  615,000 cy required for each re-nourishment

BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District PROJECT PLAN BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District 4  1) Placement: Place approximately 1.1M CY of sand on Lido Key  2) Source: Obtain Sediment for Nourishment of Lido Key Egmont Key (Tampa Bay) Offshore of Longboat Key Ebb Shoal at Big Sarasota Pass (BSP) New Pass – Future  3) Retain: Construct Three (3) groins at the south end of Lido Key

BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District PLACEMENT – LIDO KEY BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District 5 MHW Line - Design Berm 2013 MHW Line MHW Line - Advanced Berm FDEP Monument R-39 (Lime Tree Resort/Condos) 150’ 80’ Design 5’ Advanced Berm

BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District SOURCE – BSP BORROW AREAS BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District 6 D2 C B

BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District RETAIN – SOUTHERN GROINS BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District 7 Retain Beach Nourishment

BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District PROJECT PLAN – BORROW AREA QUESTIONS? PROJECT PLAN – BORROW AREA QUESTIONS?

BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District BORROW AREAS?  What are the proposed borrow area footprints?  How will this affect Big Sarasota Pass morphology?  How will this affect Siesta Key?  What are the effects on the navigation channel?

BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District BORROW AREA FOOTPRINTS D2 C B

BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District Flood Marginal Channel Relic Channel Updrift Shoal Main Ebb Channel Distal Lobe Downdrift Attachment Flood Marginal Channel In the long term: These areas will be deeper Existing Conditions

BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District % Increase in wave energy here and here % Decrease in wave energy here and here Results from the CMS morphologic model yields No indication of increased erosion over the Existing Condition at Siesta Key HOW WILL THIS AFFECT SIESTA KEY?

BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District Navigable water greater than 6m depth without project Navigable water greater than 6m depth with project No significant difference in navigable water depths without and with project EFFECT ON CURRENT NAVIGATION?

BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District PROJECT PLAN – SOUTHERN GROINS GENERAL QUESTIONS? PROJECT PLAN – SOUTHERN GROINS GENERAL QUESTIONS?

BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District SOUTH LIDO KEY GROINS  What are the plans for the groins? How long are they? How much space is between them? How big are they? Can I walk along the beach? Can I swim in the surf zone? Can I navigate past them?

BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District 350’ 500’ 460’ 600’ 800’ 2004 Present Day HOW LONG? HOW MUCH SPACE IN BETWEEN ?

BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District HOW BIG ARE THEY?

BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District CAN I WALK ALONG THE BEACH?

BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District CAN I SWIM IN THE SURF ZONE? CAN I NAVIGATE PAST THEM?

BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District PROJECT PLAN – SOUTHERN GROINS HYPOTHETICAL QUESTIONS? PROJECT PLAN – SOUTHERN GROINS HYPOTHETICAL QUESTIONS?

BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District What if the groins do not work?  What is the effect on Lido Beach?  What is the effect on Siesta Key?  How will the groins affect the ebb shoal in BSP?  Why nourish the beach if we are installing structures?

BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District Downdrift Effects Sediment Bypassing to BSP Ebb Shoal Groins are constructed to anchor the nourishment template – not to intercept Sediment at the expense of downdrift beaches or ebb shoal morphology! WHAT IS THE EFFECT ON LIDO KEY? WHAT IS THE EFFECT ON SIESTA KEY?

BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District How will the groins affect the ebb shoal in BSP? Downdrift Effects Sediment Bypassing to BSP Ebb Shoal Adequate sediment bypassing at the seaward end of the groin structures will deter the growth of a crescentic shoreline. Adequate bypassing to the Ebb Shoal ensures that BSP will maintain its morphology – seen by lack of erosion in the shoal itself

BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District Why nourish the beach if we are installing structures? Groins are constructed to anchor the nourishment template – not to intercept sediment at the expense of downdrift beaches or ebb shoal morphology! Groin construction without an associated nourishment project can lead to downdrift erosion and a lack of sediment supply to downdrift systems The groins are designed to work with the nourishment design template – should the beach erode shoreward of the design template, Emergency measures are implemented

BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District Groins – Anchor the Nourishment Beach Nourishment Retain

BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | Jacksonville District Questions/Discussions Milan A. Mora, P.E. Project Manager Jacksonville District Water Resources Branch 701 San Marco Boulevard Jacksonville, FL LIDO KEY SPP