Upload
others
View
4
Download
0
Embed Size (px)
Citation preview
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
2
Overview of Project Locations
3
Overview of Project Locations
4
Eglin AFB Beach Restoration Project
5
6
7
8
9
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
10
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
11
12
Western Destin Beach Restoration Project
13
14
15
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
16
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
17
18
19
Destin/Walton County Beach Restoration Project
20
21
22
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)
23
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
24
25
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
26
27
28
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
29
Fill Template Comparison
30
Qualitative Comparison of Design and Evolution Eglin Air Force Base
31
Qualitative Comparison of Design and Evolution Eglin Air Force Base
32
Qualitative Comparison of Design and Evolution Western Destin
33
Qualitative Comparison of Design and Evolution Western Destin – Gap Area
34
Qualitative Comparison of Design and Evolution Walton/Destin
35
Qualitative Comparison of Design and Evolution Walton/Destin
36
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
37
Thank you! Questions?
38