Beach Restoration in Okaloosa and Walton Counties · PRESENTATION OUTLINE 1. Overview of Project...

Beach Restoration

in Okaloosa and

Walton Counties

FSBPA Technology Conference Clearwater, FL

Presented by: Duncan Greer, E.I.

February 5, 2015

PRESENTATION OUTLINE

1. Overview of Project Locations

2. Eglin Air Force Base (AFB) Beach Restoration

3. Western Destin Beach Restoration

4. Destin/Walton County Beach Restoration

5. Qualitative Design Comparisons

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Overview of Project Locations

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Overview of Project Locations

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Eglin AFB Beach Restoration Project

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Eglin AFB Beach Restoration Project

• Mission Control Structures

• Project Construction: April – June 2010

• Reach 1 Approximately 3,500 feet constructed – ~265,000 cy (75.7 cy/ft)

V-511 to V-514.5 (Okaloosa County)

• Reach 3 Approximately 7,000 feet long – ~730,000 cy (104.3 cy/ft)

V-604.5 to V-611.5 (Okaloosa County)

• Funding limitations amidst Oil Spill

Reach 1 - 9,500 feet – not constructed

Reach 2 – not constructed

• Permit Expired: March 2014

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3rd Year Monitoring Report: September 2013 • Project Areas (Pre-construction vs. 3-year condition)

Average MHW +47 ft in Reach 1 and +88 ft in Reach 3

Net 81,300 cy in Reach 1 and 525,500 cy in Reach 2

• Control Areas (Pre-construction vs. 3-year condition)

Reach 1 West +17,500cy (+28.6 ft), East -71,700 cy (+12.0 ft)

Reach 3 West +185,700cy (+20.5 ft), East +23,100 cy (+6.3 ft)

• Summary

~72% (Reach 3) and ~31% (Reach 1) of placed volume

Reach 1 underperformed, 24% constructed, tropical activity in 2012

Reach 3 exceeded performance expectations, USACE 2010 placements

Eglin AFB Beach Restoration Project

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Western Destin Beach Restoration Project

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Western Destin Beach Restoration Project • Project Construction: January 29 – February 25, 2013

• Reach 1 Approximately 4,100 ft - ~487,000 cy (118.8 cy/ft)

East Jetty to R-20.7

• Gap Area Approximately 2,900 ft

18 single family lots / 3 condominium properties

• Reach 2 Approximately 2,250 ft ~147,000 cy (65.3 cy/ft)

R-23.5 to R-25.5

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1st Year Monitoring Report: October 2014 • Project Areas (Pre-construction vs. 1-year condition)

Average MHW +123 ft in Reach 1 and +65 ft in Reach 2

+409,100 cy in Reach 1 and +100,900 cy in Reach 2

• Control Areas (Pre-construction vs. 1-year condition)

Gap Area +112,900 cy (MHW +68 ft)

East Control Area +13,400 cy (MHW +40 ft)

• Summary

Project contains ~80% of initial volume

Compared to 1-year predictions, 16-month results

Reach 1 (+19%), Reach 2 (+23%)

Post-Con to 1-Yr comparisons: Gap accreted 57,600 cy

Western Destin Beach Restoration Project

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Destin/Walton County Beach Restoration Project

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Destin / Walton County Beach Nourishment Project • Sequential Erosion

• Approximately 7 miles of beach - 2.8M cy (75 cy/ft)

R-39 (Okaloosa County) to R-23.85 (Walton County)

• Project Construction

February – May 2006 (R-6 to R23.8 Walton County)

December – January 2007 (R-1 to R-6 Walton County)

May – June 2007 (R-39 to R-50 Okaloosa County)

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Destin/Walton Beach Nourishment Project 7th Year Final Monitoring Report: October 2014 • Beach and Offshore Areas (Pre-construction vs. 7-year condition)

Average MHW +114 ft

Average MHW +62 ft within control areas

Net accretion of 2,177,800 cy in project area

• Borrow Area

Continues to accumulate material (gained 613,060 cy since construction)

No adverse effects on neighboring shoreline

• Summary

Project contains ~78% of initial volume compared to pay surveys

Project contains 94% - 99% of initial volume compared to 2007 Post-Const.

Apparent equilibrium

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Successfully Met The Design Goals • Storm induced erosion mitigated

• Pre-Opal conditions

• Increased storm protection to upland properties and structures

Increased berm widths and offshore bar formations

Withstood numerous storm events (TS Barry, Erin, Eduardo, Fay, Claudette, Lee, Debby, Beryl, Andrea and Hurricanes Gustav, Ike, Ida, Isaac)

• Aesthetically pleasing and provides increased recreational benefits

• Provides enhanced marine turtle and nesting shorebird habitat

Destin/ Walton Project Monitoring Summary

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Design Comparison Variables • Typical beach nourishment design principles

Project length, fill density, overfill ratios, background erosion rates, etc.

• Project timelines / timescales

• Eroded condition of the pre-construction project area

Initial profile condition can significantly affect equilibration

• Naturally occurring phenomena

Offshore / nearshore bar migration or welding

Beach cusps (prevalent in this area of Florida)

Dominant coastal features (historic rip channels, erosion hotspots, etc)

• Storm impacts and seasonal variability

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Fill Template Comparison

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Qualitative Comparison of Design and Evolution Eglin Air Force Base

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Qualitative Comparison of Design and Evolution Eglin Air Force Base

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Qualitative Comparison of Design and Evolution Western Destin

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Qualitative Comparison of Design and Evolution Western Destin – Gap Area

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Qualitative Comparison of Design and Evolution Walton/Destin

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Qualitative Comparison of Design and Evolution Walton/Destin

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Discussion of Qualitative Design Comparisons • Eglin AFB

Maintained back berm – increased dune protection

Generally maintained berm elevation

• Western Destin

Still equilibrating

• Walton/Destin

Berm reduced after 1-2 years (Ike and Gustav)

Larger transition from dune to berm

Good performance overall, design goals achieved

• One size does not fit all

• All designs perform as desired

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Thank you! Questions?

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