Sarasota county lido key hurricane storm damage reduction project
This presentation is the property of its rightful owner.
Sponsored Links
1 / 26

SARASOTA COUNTY – LIDO KEY HURRICANE & STORM DAMAGE REDUCTION PROJECT PowerPoint PPT Presentation


  • 95 Views
  • Uploaded on
  • Presentation posted in: General

BUILDING STRONG ® US ARMY CORPS OF ENGINEERS | JACKSONVILLE DISTRICT. SARASOTA COUNTY – LIDO KEY HURRICANE & STORM DAMAGE REDUCTION PROJECT. Information Presentation BOCC Joint Meeting . City of Sarasota Sarasota County US Army Corps of Engineers 22 October 2013 Sarasota, Florida

Download Presentation

SARASOTA COUNTY – LIDO KEY HURRICANE & STORM DAMAGE REDUCTION PROJECT

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Sarasota county lido key hurricane storm damage reduction project

BUILDING STRONG®US ARMY CORPS OF ENGINEERS | JACKSONVILLE DISTRICT

SARASOTA COUNTY – LIDO KEY HURRICANE & STORM DAMAGE REDUCTION PROJECT

Information Presentation

BOCC Joint Meeting

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


Overview project scope

2

US ARMY CORPS OF ENGINEERS | Jacksonville District

BUILDING STRONG®

OVERVIEW – PROJECT SCOPE

  • Authorized WRDA 1999

    • Authority was contingent on a feasibility assessment of the project.

    • 2002 Feasibility Study with Environmental Assessment (amended April 2004) determined that project was technically sound, environmentally acceptable and economically justified.

1971

1986

2006


Overview project features

3

US ARMY CORPS OF ENGINEERS | Jacksonville District

BUILDING STRONG®

OVERVIEW – PROJECT FEATURES

  • 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

80 ft Design Berm

over 1.6 miles

3 Proposed Sand Sources

Groin Field (3)

D2

C

B


Project plan

4

US ARMY CORPS OF ENGINEERS | Jacksonville District

BUILDING STRONG®

PROJECT PLAN

  • 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


Placement lido key

5

US ARMY CORPS OF ENGINEERS | Jacksonville District

BUILDING STRONG®

PLACEMENT – LIDO KEY

2013 MHW Line

80’ Design Berm @ 5’

MHW Line - Design Berm

MHW Line - Advanced Berm

Advanced Berm

150’

150’

  • FDEP Monument R-39

  • (Lime Tree Resort/Condos)


Source bsp borrow areas

6

US ARMY CORPS OF ENGINEERS | Jacksonville District

BUILDING STRONG®

SOURCE – BSP BORROW AREAS

D2

C

B


Retain southern groins

7

US ARMY CORPS OF ENGINEERS | Jacksonville District

BUILDING STRONG®

RETAIN – SOUTHERN GROINS

Beach Nourishment

Retain


Sarasota county lido key hurricane storm damage reduction project

US ARMY CORPS OF ENGINEERS | Jacksonville District

BUILDING STRONG®

PROJECT PLAN –

BORROW AREA QUESTIONS?


Borrow areas

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?


Sarasota county lido key hurricane storm damage reduction project

BORROW AREA FOOTPRINTS

alt d2, C, B – 1.7 mcY

D2

C

B


Sarasota county lido key hurricane storm damage reduction project

BSP MORPHOLOGY

Relic Channel

In the long term:

These areas will be deeper

Flood Marginal Channel

Updrift Shoal

Flood Marginal Channel

Main Ebb Channel

Distal Lobe

Downdrift

Attachment

Existing Conditions


Sarasota county lido key hurricane storm damage reduction project

HOW WILL THIS AFFECT SIESTA KEY?

Results from the CMS morphologic model yields No indication of increased erosion over the Existing Condition at Siesta Key

% Increase in wave energy here and here

% Decrease in wave energy here and here


Sarasota county lido key hurricane storm damage reduction project

EFFECT ON CURRENTNAVIGATION?

No significant difference in navigable water depths without and with project

Navigable water greater than 6m depth without project

Navigable water greater than 6m depth with project


Sarasota county lido key hurricane storm damage reduction project

US ARMY CORPS OF ENGINEERS | Jacksonville District

BUILDING STRONG®

PROJECT PLAN –

SOUTHERN GROINS

GENERALQUESTIONS?


South lido key groins

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?


How long how much space in between

HOW LONG? HOW MUCH SPACE IN BETWEEN ?

460’

800’

600’

500’

350’

2004

Present Day


How big are they

HOW BIG ARE THEY?


Can i walk along the beach

CAN I WALK ALONG THE BEACH?


Can i swim in the surf zone can i navigate past them

CAN I SWIM IN THE SURF ZONE? CAN I NAVIGATE PAST THEM?


Sarasota county lido key hurricane storm damage reduction project

US ARMY CORPS OF ENGINEERS | Jacksonville District

BUILDING STRONG®

PROJECT PLAN –

SOUTHERN GROINS

HYPOTHETICALQUESTIONS?


What if the groins do not work

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?


What is the effect on lido key what is the effect on siesta key

WHAT IS THE EFFECT ON LIDO KEY?WHAT IS THE EFFECT ON SIESTA KEY?

Sediment Bypassing to BSP Ebb Shoal

Downdrift Effects

Groins are constructed to anchor the nourishment template – not to intercept

Sediment at the expense of downdrift beaches or ebb shoal morphology!


How will the groins affect the ebb shoal in bsp

How will the groins affect the ebb shoal in BSP?

Sediment Bypassing to BSP Ebb Shoal

Downdrift Effects

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


Why nourish the beach if we are installing structures

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


Groins anchor the nourishment

Groins – Anchor the Nourishment

Beach Nourishment

1986

Retain

1983

1981


Lido key spp

US ARMY CORPS OF ENGINEERS | Jacksonville District

BUILDING STRONG®

LIDO KEY SPP

Questions/Discussions

Milan A. Mora, P.E.

Project Manager

Jacksonville District

Water Resources Branch

701 San Marco Boulevard

Jacksonville, FL 32207

904-232-1454

[email protected]


  • Login