Citation
Part 1: Description and analysis of changes

Material Information

Title:
Part 1: Description and analysis of changes
Series Title:
Dade County, Florida, Beach Nourishment Project
Creator:
Liotta, Roberto
Place of Publication:
Gainesville, Fla.
Publisher:
Coastal & Oceanographic Engineering Dept. of Civil & Coastal Engineering, University of Florida
Language:
English

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Source Institution:
University of Florida
Holding Location:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.

Full Text
UFL/COEL-98/018

DADE COUNTY, FLORIDA, BEACH NOURISHMENT PROJECT PART 1: DESCRIPTION AND ANALYSIS OF CHANGES
by
Roberto Liotta and
Robert G. Dean

November 1998




Dade County, Florida, Beach Nourishment Project

Part 1: Description and Analysis of Changes
November 18, 1998
by
Roberto Liotta and
Robert G. Dean

Project Sponsor:
Division of Beaches and Coastal Systems Department of Environmental Protection
Tallahassee, Florida 32399
Submitted by:
Department of Coastal & Oceanographic Engineering
University of Florida
Gainesville, Florida 32611




Dade Countv, Florida, Beach Nourishment Project Description and Analysis of changes
Table of Contents
Page
List of Figures. ill
List of Tables. v
1.0 Introduction and Purpose 1
2.0 Background. 1
2.1 General. 1
2.1.1 Government Cut. 2
2.1.2 Bakers Haulover Inlet. 3
2.1.3 September 1926 Hurricane. 3
2.1.4 Construction of Shoreline Stabilization Structures. 3
2.1.5 Dade County, Florida, Beach Erosion and Hurricane
Surge Protection Project. 5
2.1.6 Renourishments. 7
3.0 Data Sources .. 8
4.0 Data Analysis. 10
4.1 Beach Profiles and Sand Characteristics. 10
4.1.1 Beach Profiles. 10
4.1.2 Sand Characteristics. 11
4.2 Shorelines. 13
4.3 Sand Volume Changes 18
4.4 Interpretations. 25
4.4.1 Model for Shoreline Displacement. 25
4.4.2 Consideration of Shoreline Change due to
Profile Equilibration. 27




Dade Countv, Florida, Beach Nourishment Project
5.0 Conclusions
6.0 References.
Appendix A: Beach Profile Survey Data Appendix B: Summary Plots of Longshore Distribution of
Shoreline and Volume Changes.

Description and Analvsis ofchian es




n I- /laLLt VU I ;jl SILLS SiC U (JtLJL L C (LLI L(il L (VLLt L(1tS ,I(LS V.13 t( (IWL C3

List of Figures
Figure Page
1 County Location for the Study Area. 2
2 Bal Harbour Beach after the 1975 Nourishment and Surfside Beach
Before the 1976 Nourishment. 4
3 Groin System North of Lummus Park. 4
4 Borrow Site Locations for the Beach Nourishment Project. 6
5 Map of the Different Phases of the Beach Nourishment Project. 7
6 Comparison between 1980 and 1996 Average Profiles. 11
7 Sand Grain Size Distribution, Dade County Nourishment Project.. 12
8 Sand Grain Size Composite Frequency Curves,
Dade County Nourishment.. 13
9 Cross-Shore Distribution of Average Median Sediment Size. 13
10 Shoreline Positions for Different Periods Relative to the Shoreline Position of 1962. 14
11 Annual Rate of Shoreline Change for a Five Month Period Between 1980 and 1981. 16
12 Annual Shoreline Change Rate for the Period 1992 to 1996, Shoreline Change from 1962 to 1996 and Number of Years for the
Shoreline to Reach the 1962 Position Based on 1992 to 1996
Erosion Rate. 17
13 Total Volume Changes and Volume Added Relative to 1962 Between Bakers Haulover Inlet and Government Cut. 21




flpvcrntrnn (ifld 4naIt'.a'~- nfchnwp~

Figure Page
14 Total Volume Changes Relative to 1980 Between Bakers Haulover Inlet and Government Cut. 23
15 Comparison Between Volume Changes per Unit Length Based on Profile Changes and Shoreline Changes. 24
16 Components of Measured Shoreline Displacements. 26
17 Model for Shoreline Changes due to a Single Nourishment. 28
18 Average Shoreline Changes (Best Fitting Curve) for the Reach Between Bakers Haulover Inlet and Monument R-65. 29

Dade Countv Florida Beach Nourishment Proiect Descri tion anti AnaNsis of chan es




flad~ CnIn;1 Finrida R~arIi Afniridinoir Prn,,~t

List of Tables
Table Page
1 Characteristics of the Five Phases of the Dade County Beach
Nourishment Project. 6
2 Available Survey Data for Miami Beach. 8
3 Volume Changes Characteristics for Various Beach Segments,
1992-1996. 19
4 Hot Spot Characteristics, 1992-1996. 19
5 Volumetric Changes Characteristics, from R-58 to R-65 for
Various Depth Ranges, 1981-1986.. 20
6 List of the Most Significant Events. 22
7 Comparison of Average Shoreline Changes Relative to 1980. 27
8 Data Used in Determining Decay Parameter, k. 28

Dade Countv orida Beach Nourishment Proiect e-rw on an na v,';'3 OU anges




Dade County, Florida, Beach Nourishment Project
Part 1: Description and Analysis of Changes
1- Introduction and Purpose
This report documents the background and performance of the "Dade County Beach Nourishment Project", which was constructed over the period 1976 to 1983. This report presents data and analysis results based on beach profile monitoring, and the resulting shoreline changes and sand volume changes. The report draws upon monitoring data available for the period preceding and following the beach nourishment project for quantitative analysis of the beach fill performance and understanding of coastal processes in the study area, focusing particularly on areas within the project which, atypically, perform poorly compared to expectations or neighboring areas. These areas are called "Erosional Hot Spots" (EHS). Also presented are evaluations of the overall performance of the project.
This report includes appendixes that provide access to much of the processed data for analysis by others, who may be interested in greater detail. Appendix A presents plots of the profile survey data listed by DEP Monument Number for visual inspection and Appendix B provides plots of shoreline and volume changes for different periods.
2- Background
2.1 General
The study area, which is approximately 9.2 miles (14.8 km) long, is located in Dade County on the southeast coast of Florida (Figure 1) and includes the beaches of Miami Beach, Surfside and Bal Harbour. The most substantial shoreline changes in this general area have occurred as a result




.... ......ni lr id...... ..........................riv io an A ay i o ch ne
of various coastal engineering projects and natural processes, including:
- The excavation of Government Cut at the south end of Miami Beach in 1904, included the
construction of two jetties.
- The excavation of Bakers Haulover Inlet at the north end of Miami Beach in 1925, included
the construction of two jetties.
- The September 1926 hurricane which impacted the Miami area.
- The construction of a system of seawalls and abutting groins along the beach.
- The encroachment of construction onto the active beach.
- The Dade County, Florida, Beach Erosion Control and Hurricane Surge Protection Project
(1976-1981).
- Renourishments in 1960-69, 1981-92 and 1994. Each of these is discussed in the following sections.
0N
FLORIDA
Figure 1: County Location for the Study Area.
2.1.1 Government Cut
The initial Government Cut federal navigation project commenced in 1904 and included the construction of a north jetty, which was extended seaward different times in subsequent years, reaching the present length of 4,688 feet (1434 m) in 1929. It was repaired and sand tightened in

rDndi, County Florida Beacrh Nnurikhmpnt Project

Description and ,4nalvsis of changes




n~~~4L V._ /'I r11_ *a..- DJUf 1. M-W~ltlfUI~lL '-I. Dtl n ~ ft ;il~ Y;t 4 1 1 1.

1959-60 in order to reduce the deposition of sand in the entrance channel, due to the Iongshore sediment transport toward the south. In 1973, another project to further sand-tighten the north jetty was conducted. At that time, significant quantities of sand and rock were placed along the north side of the jetty. After the beach nourishment project was completed in 1983, another repair effort was necessary to sand-tighten the more seaward section of the jetty.
2.1.2 Bakers Haulover Inlet
The Bakers Haulover Inlet project was excavated in 1925 and sponsored by local interests. It was stabilized by two short jetties. After the south jetty was destroyed by the 1926 hurricane, it was rebuilt in 1964, as part of a Federal navigation project. In July 1975, the south jetty was extended seaward about 735 feet (224 m) and curved southerly to deflect alongshore currents to the south and encourage a gyre to reduce these currents and minimize sand losses (Figure 2).
2.1.3 September 1926 Hurricane
"The September 1926 hurricane has been the most severe hurricane that impacted Miami Beach since records have been kept. The barrier island was inundated by a combination of astronomical tide, storm surge, wave setup and wave runup, with water depths over the island up to 3 feet (1.0 m), and with water ponded in a few places near the ocean to an elevation of from 10 to 11 feet (3 m) above MLW. During the hurricane, a large amount of sand was transported up to 1,000 feet (300 m) inland from the beach covering the streets of the city with 3 feet (1 m) of sand" (Wiegel, 1992). It was also during this hurricane that the north and south jetties of Bakers Haulover Inlet were destroyed and the bridge, located landward of the jetty, was left standing 160 feet (49 m) offshore as a result of erosion. Later the bridge was relocated farther landward.
2.1.4 Construction of Shoreline Stabilization Structures
The development of the area resulted in many hotels and private construction located in proximity to the shoreline. In some cases, hotels expanded their facilities seaward of the existing MHW. An almost continuous line of seawalls was built to protect these facilities from wave attack. These seawalls survived surprisingly well during the 1926 hurricane. After the 1926 hurricane, in




('nufln' ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ I -I-lI', ; ~ Pr, ) ,,II ,,~,vnr~na

Figure 2: Bal Harbour Beach after the 1975 Nourishment and Surfside Beach
before the 1976 Nourishment.

Figure 3: Groin System North of Lummus Park (1954).




Dande Conn, o/rinn Beach ANurishmepnt Praoret flovrrintinn and Anal, is. ofchaoes

order to control the beach erosion processes (stabilize the shoreline), a system of perpendicular groins was built from Bakers Haulover Inlet to Lummus Park, located approximately 2 km north of Government Cut (Figure 3). Most of these groins were sponsored by private interests. Many extended up to 50 m ( ft) seaward of the MHW line. By 1975, more than 48,000 linear feet (14.6 km) of seawalls and numerous groins have been constructed.
2.1.5 Dade County, Florida, Beach Erosion and Hurricane Surge Protection Project
The Beach Erosion Control and Hurricane Surge Protection Project was authorized by Congress in 1968 and was constructed from 1976-1981.This project was designed for beach erosion control and also to provide hurricane protection for a storm of intensity similar to that which had occurred in 1926. Moreover, it provided a recreational beach along Dade County. The design increased the beach width to 250-300 feet (75-90 m) and included a dune with an elevation of 11.5 feet (3.5 m) above MLW. The design life of the project was 50 years, with estimated renourishment on the order of 191,000 cu yd/year (145,160 M3 /year) for the reach between Government Cut and Bakers Haulover Inlet, amounting to 3.75 cu yd/year per linear foot (9.35 m3/year per linear meter), (R. L., Wiegel, 1992). The total amount of fill was approximately 13.9 million cu yd (10.5 million in3), including the 1975 Bal Harbour fill. The sand was dredged from nearby offshore borrow areas and pumped to the beach, as shown in Figure 4. The seawalls and the abutting groins were not removed but were covered by the fill.
Local interests had placed sand south of Bakers Haulover Inlet on six occasions between September 1960 and August 1969, averaging 30,500 cu yd/year (23,180 M3 /year). Also in July 1975, local interests contracted for the placement of 1.625 million cu yd (1.235 million m3) of beach fill along the 0.85 mile (1.37 km) Bal Harbour reach; at the same time, as noted previously, the south jetty of Bakers Haulover Inlet was extended approximately 735 feet (224 in).
Due to the magnitude of the complete Dade County project, it was realized in five different phases and contracts (Figure 5), which are summarized in Table 1:




Table I
Characteristics of the Five Phases of the Dade County Beach Nourishment Project.
Phase Period of Work Area Encompassed Volume of Sand Unit Cost
no. (Streets) Placed ($/cu yd)
(cu yd )
I May 1977 September.1978 from 80'h to 96'h 2,940,000 1.95
+ Haulover Beach Park
2 August 1978 1979 from 63 d to 80' 1,530,000 1.87
3 August 1978 1980 from 36h to 63rd 3,177,100 2.66
4 May 1980 October 1981 from 16'h to 36th 2,200,000 4.95
5 October 1981 January 1982 from Govern. Cut to 16th 2,400,000 9.00

The total amount of sand placed was cu yd of 1975 Bal Harbour fill.

13.9 million cu yd (10.6 million M3), including 1.65 million

Figure 4: Borrow Site Locations for the Beach Nourishment Project




avuu evt&rV. I vn.1" r veuc I ruIur men.1rC tJaU ecr lJJ tl llC VLon ME LVU nl-CJ
F) /- J7- *4- D 1. r- 'Z. D- r 4 Ip

R-30
R-40 R-50 R-60

Ist PHASE ut C
ist PHASE 02nd PHASE 2nd PHASE

3rd PHASE 4th PHASE

R-70 Sth PHASE
SGov,,ernment Cut

C, (0
-I-I

Scale:
0 2 4 6 a
Miles
Dade County, FL

Figure 5: Map of the Five Different Phases of the Beach Nourishment Project
2.1.6 Renourishments
Before the Dade County Beach Erosion and Hurricane Surge Protection Project was constructed, local interests placed sand south of Bakers Haulover Inlet between 1960 and 1969, averaging 30,500 cu yd/year. After the project was constructed, in some particular areas

D i i d A l h




fl~A0 ('nunt,, Pin rAn Ran ,4, AJn,,ricImonr Pm rant

renourishment projects were required: 122,200 m3 (160,000 cu yd) between 63rd and 71 t Streets. (R46 and R-41 Monuments) and 53,500 m3 (70,000 cu yd) between 27h and 34th Streets (approximately between R-61 and R-58) were placed in 1985, and 175,700 m3 (230,000 cu yd) placed at Bal Harbour Beach in 1990. Moreover, 91,700 m3 (120,000 cu yd) of sand were placed between R-55 and R-56 in 1994 (Dade County Regional Sediment Budget, 1997). The total renourishment has been 653,000 m3 (855,000 cu yd).
3- Data Sources
Miami Beach has been one of the most important tourist areas in Florida since the beginning of the century. Profiles in this study area have been surveyed several times and most of the data are available on the internet at the web page "Beach and Offshore Profile Data" of the State of Florida, Department of Environmental Protection.
The data available are summarized in Table 2.
Table 2
Available Survey Data for Miami Beach.
Date Source Offshore Extent of Data Description
Data on Average (in)
1962 DEP" Shoreline Position
1969 UF Project 6906 400 Beach Profiles
1975 DEP Shoreline Position
November 1980 DEP 450 Beach Profiles
March 1981 CCCL'" Shoreline Position
February 1986 DEP 100 Beach Profiles-*
August 1992"*" DEP Water Line NGVD Beach Profiles****
June 1996 DEP 700 Beach Profiles
DEP Department of Environmental Protection.
CCCL Coastal Construction Control Line Photos.
After Hurricane Andrew
Wading profiles

LL, 1. - -LI anges
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flnd~ ('njntv Pinrida Rorn'Ii Nn,,rivAm~'nt Pinion

flovnrinhinn nnd AnnIuv~ ~

The beach profile data of 1986 and 1992 did not extend very far seaward (wading profiles), while the data of 1980 and 1996 extended seaward to the depth of closure (>15 ft). It must be noted that in 1992 some monuments were moved seaward from their original locations. For calculation purposes it has been assumed that only the cross-shore coordinates of the profiles from different years changed. The data obtained from the sources listed above were used to compute Mean High Water (MHW) shoreline changes as well as volume changes. Cross-sections are plotted and compared to determine long-term changes that have occurred over the 1980-1996 time period.

Dade r-un Florida Beach Nourishment Proiect Descri tion and Anal is och--




Dade County, Florida, Beach Nourishment Project Description and Analysis of chatzees
4- Data Analysis
4.1- Beach Profiles and Sand Characteristics
4.1.1 Beach Profiles
Comparative profiles have been plotted for the area of interest at each monument and are presented in Appendix A. The 1980 and 1996 data extend farther offshore than the 1969, 1986 and 1992 data. The slope of the beach fill project was on average 1:20 as shown by the 1980 beach profiles from Monument R-27 to R-65. The 1996 profiles are steeper in the foreshore zone followed by a trough at approximately -2.0 m depth (6.0 ft) and by a milder slope over the rest of the profile reaching the depth of closure, which is on average 5.0 m (16 ft). In most of the profiles from Monument R-27 to R-49 and from R-58 to R-62 it appears that between 1980 and 1996 the sand has migrated seaward from the foreshore, causing a recession of the shoreline, and deposited on the bar but still inside the nearshore zone (see Figure 6, panel c). In the 1996 profiles from Monument R-50 to R-58 the sand from the foreshore zone has migrated cross-shore out of the nearshore zone or has migrated longshore impounding downdrift near the north jetty of Government Cut (see Figure 6, panel d). The 1996 beach profiles from Monument R-60 to R-74 have almost the same shape as the previous 1992 profiles, as shown in Appendix A. Compared to the 1980, 1986 and 1992 data, there has been deposition on the foreshore zone and also on the bar causing an accretion of the shoreline. Panel a of Figure 6 compares the average profiles of 1980 and 1996 computed for the reach between Bakers Haulover Inlet (Monument R-27) and Monument R-65, and panel b between R-65 and Government Cut (Monument R-74). Also, panel a shows that the 1996 profile has adjusted toward a new equilibrium. The significant difference between the 1980 and 1996 profiles in panel b is primarily due to the construction of 5 h Phase of the Nourishment Project.

-10-




D C For id .. ............. r. i description and Anal sis of changes
4 4
a) b
2 2
0 'MHW 0 '\ MHW
00
C (3)
4 -4
-from Monum. R-27 to R649 a"
-from Monum. R-27 to R65. -from Monum. R-66 to R74.
0 100 200 300 400 0 100 200 300 400
4 4
C) Od) Dm 1o
Foe 1996 A Pa ) 996 r u
2 MHW MHW
C0 0
l -2 -2 .
u.J
-4- -4 .
-from Monum. R-27 to R-49 an
-6 -from Monum. R-58 to R-62. -6 from Monum. R-50 to R58.
0 100 200 300 400 0 100 200 300 400
Offshore Distance from Monument (m) Offshore Distance from Monument (m)
Figure 6: Comparison Between 1980 and 1996 Average Profiles. (Panel a) from Bakers Haulover
Inlet to Monument R-65. (Panel b) from Monument R-66 to Government Cut.
(Panel c) from Monument R-27 to R-49 and from R-58 to R-62.
(Panel a) from Monument R-50 to R-58.
4.1.2 Sand Characteristics
In 1977-78, before the placement of fill, the Jacksonville District of the U.S. Army Corps of Engineers (USA/CESAJ) took "native beach" sand samples along profile lines 0.5 miles apart. After project completion, other samples were taken. Figure 7 is a sample curve and Figure 8 presents some composite information, quantifying the profile characteristics. The mean grain sizes of the native beach, borrow areas and project are 1.59 4 (d=0.33 mm), 1.71 1 (d=0.30 mm) and #=1.46 (d=0.36 mm), respectively. Based on these figures the Corps comments (USA/CESAJ, General Design Memorandum Addendum III, Sept. 1986):

D-* ; .. ,.I.: Z




Dadeh Countv Florida Re'ach Nouishmnt Proliet flescrintion and Ana/v'.is ofrJ,,nOs

All three composite distributions are poorly sorted. The native beach curve is better sorted than the Project borrow and post-nourishment curves. The post-nourishment material is slightly better sorted than the in-place material". Also they comment that "The visual estimate of shell content for the native beach was 23 percent. The in place borrow material was 34 percent shell and the post nourishment beach was 39 percent shell. The higher percentage of shell in the fill material reflects the high carbonate content of the sand in the borrow areas". Figure 9 presents the cross-shore distribution of average median sediment size (d50) computed by

COMPOSITE GRAIN SIZE IDIST RIBU TONS 99
,BOROW MATERIAL / / !
1A A, 8, C, D, E OF. RAN W'Z 0 1.71
PROJECT PE IlOl !AlC70
1IS.2 BEACH
MEAN GRA[I SIZE 14 115 If
PH SOTN 1.8
:-o
"0 1
-4 -3 -2 0 2 3 4
GRAIN SIZE" (9) UNITS)

Figure 7: Sand Grain Size Distribution, Dade County Nourishment Project.
averaging data of 8 profiles within the area of interest (Charles, 1994). Note the relative high values of d50 close to the shoreline, over 0.7 mm, and the decrease to around 0.2 mm at a seaward distance of 100 m. Still farther seaward the value of d,0 increases again reaching almost 0.45 mm at 300 m offshore.

-12-




Dade run Floriuda Rach ANri hment Pr ar; flovrrin in -nd4. ntr; hnn

COMPOSITE FREQUENCY CURVES

* NATIVE BEACH MATERIAL.1977- l7a
A BORROW MATERIAL
E PROJECT PERFORMANCE BEACH SAMPLING 1982
PROJECT PERFORMANCE CURVE
M-TA GRAN SAE STATISTIC INTIFTI

16 6 4 2 I 05 0.25 0.125 0.063
MM
GRAIN SIZE

Figure 8: Sand Grain Size Composite Frequency Curves, Dade County Nourishment.

O 50 100 150 200
Offshore Distanc O from Shorelie (m)

Figure 9: Cross-Shore Distribution of Average Median Sediment Size, (Charles, 1994).
4.2- Shorelines
Figure 10 presents the shoreline positions for different years relative to the shoreline position of 1962, before the Beach Erosion Control and Hurricane Protection Project was initiated. Several results are evident from Figure 10:




,inulvsLs oj cnan~es

,:,, ,,tiv ,i tilrtc1 tt -1 .(,( l tur / t s me roLec, lje scriptIOn anu a/tav, lS oL cntan~es
200
Ocean 0 "
19 1- /
1 992
139, 6 \ -" /\ ,, $ ,
150o A' *A .
<= / : 4) 4.a),,1-" "-U1 /
1o \ '.\
0
U)
0 x x x X X X X) x( X x< XK < X 9 X 11 1- X, :Y X X X Y X X, x x, X X< X X x x( Y+. xx X X x :.i 1
Bakers Haulover Inlet Government Cut ..... .....
'50- 1 0
"215 30 35 40 45 50 55 60 65 70 75
DEP Monument No.
Figure 10: Shoreline Positions for Different Periods Relative to the Shoreline Position of 1962.
-Between Monument R-27 and R-33, which corresponds approximately to Bal Harbour Beach, the 1975 shoreline position is located seaward of the 1962 shoreline, due to the beach fill placed between Monuments R-27 and R-31 by local interests in 1975. Also, the 1975 shoreline has advanced seaward along, the remainder of the study area, but less than in the Bal Harbour area and immediately north of Governmenet longshore sediment transport was impounded by the north jetty. This general advancement of the 1975 shoreline position Outside the area of nourishment in 1975 is probably due to the natural recovery following the Ash Wednesday storm in March 1962.
- The 1980 data show the shoreline position after the beach fill was placed from Monument placed eton Monuments R -2 anr bth shoreline ha s, T
by3 tort jety. Ithis genraldaceeto the 1975ag shoreline positionen houses areaxmael of t 15)




Dade County, Florida, Beach Nourishment Project Description and Analysis of changes
The fifth phase of the beach nourishment project, approximately from Monument R-65 to Government Cut, had not yet commenced.
- The 1981 data, as the 1980 data, show that the fifth phase of the project had not commenced. Figure 11 presents the annual rate of shoreline change between November 1980 and March 1981. In only 5 months the shoreline receded on average 13.4 m (44.0 ft), equivalent to an annual rate of 32.1 m/year (105.3 ft/year). This is a result of the beach fill profiles rapidly adjusting to reach a new equilibrium. Between Monuments R-65 and R-66 the effect of the beach fill spreading out is evident.
- The 1992 data (Figure 10) show that the shoreline receded from its position in 1981 except for the reach between Monument R-65 and Government Cut due to the shoreline advancement associated with the fifth phase of the beach nourishment project. Considering only the beach area between Bakers Haulover Inlet and Monument R-65, the annual rate of shoreline change on average is -0.9 m/year (-2.95 ft/year), which clearly shows that the beach profiles have almost reached equilibrium. A spreading effect due to the fifth phase of the nourishment can be noted updrift (north) of Monument R-65; the shoreline advanced instead of receding.
- Comparison of the data of 1996 to that of 1992 shows that the shoreline continued to recede between Bakers Haulover Inlet and Monument R-60 on average of-2.4 m/year (-9.68 ft/year), while advancing from Monument R-60 to R-70 on average of 1.7 m/year (5.58 ft/year).
Figure 12 presents the annual rate of shoreline change from 1992 to 1996 and the shoreline change from 1962 to 1996. The shoreline advancement between 1962 and 1996 is on average 98.3 m (322.4 ft) with a peak of 189.8 m (622.5 ft) at Monument R-67 and a minimum of 39.1 m (128.2 ft) at Monument R-36. Considering the annual erosional rate of 1992-1996, which is -2.4 m/year (7.87 ft/year), it would take approximately 41 years before the average shoreline again reaches the 1962 shoreline position, which implies a good performance of the complete project. However, in some locations it would take only 9-12 years to reach the 1962 shoreline position, such as at Monuments R-34, R-36, R-58 and R-59 (Figure 12, Panel c). These areas are referred as Erosional Hot Spots (EHS) with the most severe EHS at Monuments R-36 and R-59.




... ....... ......a .....A,.,,.. Fo a Anas I changes
DadeCoun FlridaBeac No-hm-t P--es

4)
1980
4) 4
0
-50
Bakers Haulover Inlet Govemmernt Cut
-100 ... .. .. ..
25 30 35 40 45 50 55 60 65 70 75
DEP Monument No.
Figure 11: Annual Rate of Shoreline Change for a Five Month Period between 1980 and 1981.
(Note: This is Primarily the Result of Profile Equilibration).

-16-

D




Dlade Cnuntv Florida Beach Nourishmeant Proipct Dp.scrintion and A nalvviv nf4n

1U I T I
(92-96) a)
5
0*
o k /
L Bakers Haulovsr Inlet Govemment Cut
-10 25 30 35 40 45 50 55 60 65 70 75

30 35 40 45 50 55
DEP Monumenrt No.

60 65 70 75

Figure 12: (Panel a) Annual Shoreline Change Rate for the Period 1992 to 1996.
(Panel b) Shoreline Change from 1962 to 1996. (Panel c) Number of Years
for the Shoreline to Reach the 1962 Position Based on 1992 to 1996
Erosion Rate.
(Note: in Panel c, only the points characterized by an erosion rate have
been included).

-17-

2

+ + c)
0
++ 0
0
l I I I l l I I




Dade ('ounti, Florida, Beach Vourishment Project Description and analysis of chances
4.3- Sand Volume Changes
The net transport of sand along the east coast of Florida is toward the south, as inferred from observations of sand impoundment at jetties and groins. Various estimates of the longshore sediment transport rate are available for the Miami Beach area. Before the beach nourishment and hurricane surge protection project started, the U.S. Army Corps of Engineers (USACE) estimated that the net transport rate was 20,000 cu yd/year (15,280 m3/year) towards the south and the magnitude was affected by the presence of groins along the beach (USA/CESAJ, General Design Memorandum Phase 1, July 1974). The Corps also estimated that the historic alongshore net transport rate would be 217,000 cu yd/year (165,788 m3/year) towards the south if there were no barriers (groins) to affect the transport, with 192,000 cu yd/year (146,688 m3/year) towards the north and 409,000 cu yd/year (312,476 m3/year) towards the south. The Coastal Engineering Research Center (CERC) later calculated a net transport of 95,000 cu yd/year (72,580 m3/year) towards the south, based on the Wave Information Study (WIS) Phase III wave data, with a gross annual transport of 220,000 cu yd/year (168,080 m3/year) (USA/CESAJ, General Design Memorandum Addendum II, June 1984). A University of Florida study, reported by Wiegel (1992), estimated a net transport of 235,000 cu yd/year (179,540 m3/year) towards the south, with 187,000 cu yd/year (142,868 m3/year) to the north and 422,000 cu yd/year (322,408 m3/year) to the south, consistent with the previous estimates of the USACE. Coastal Systems International Inc. in the Dade County Regional Sediment Budget, 1997, estimated a southerly net sediment transport of 5,000 cu yd/year (3,820 m3/year).
Data are available relative to the shoreline positions immediately after the beach restoration projects for only the first and second phases while those relative to the third through the fifth phases are available only for later periods.
Appendix B presents plots of the distribution of the annual rate of volumetric change per unit longshore distance along the beach for different time intervals. Only the volumetric changes between 1980 and 1996 have been computed from the profile data, because they extend farther than the depth of closure. The other volumetric changes have been computed from changes in shoreline position, using a berm elevation of 2.0 m (6.50 ft) and a depth of closure of 5.0 m (16.4 ft). It should be noted that, based on shoreline positions, from 1992 to 1996 the beach between Bakers Haulover Inlet and Government Cut has lost on average -8.56 m3/m per year (-3.41 cu yd/ft per year), which




fl,,,?1, (n,,nt,, Plnri4n flon,.1, AIn,,r, ehnv,,f Pr,, ,ort

U, L,,Ufl~3

in four years equals 507,200 m3 (663,900 cu yd), (Table 3). Because these results are based on shoreline changes, they are overestimates due to the effects of profile equilibration. It appears that some sand lost between R-27 and R-60 has been deposited between R-60 and R-74 creating what we can call an "erosional cold spot" (ECS).
Table 3
Volume Change Characteristics for Various Beach Segments, 1992-1996.
Monuments Annual Rate of Volume Annual Total Volume Total Volume Change
1992-1996 Change per Unit Distance Change between 1992 and 1996
per Year (m3/year) (i3)
(m3/m per year)
R-27 R-74 -8.56 -126,800 -507,200
R-27 R-60 -16.59 -170,922 -683,688
R-60 R-74 +9.80 +44,122 +176,488

(Based on Shoreline Changes)

Two erosional hot spots are located in the area of study: the first is between monuments R-55 and R-60 and the second between monuments R-33 and R-37. The characteristics of these two hot spots are summarized in Table 4.
Table 4
Hot Spot Characteristics, 1992-1996.
Hot Spot Annual Rate of Volume Change Maximum Annual Rate of Total Volume Change
on Average (m3/m per year) Volume Change (m3/m per (m3) year)
R-55 R-60 -20.35 -39.24 (R-58) -148,200
R-33 R-37 -20.57 -32.35 (R-36) -126,280
(Based on Shoreline Changes)
Volumetric changes for the reach between Monuments R-58 and R-65 are shown in Table 5, based on losses to the -6 ft (2 m) and -12 ft (4 m) contours (USA/CESAJ, General Design Memorandum Addendum III, 1986). The volumetric changes show that most losses occurred in the nearshore region (landward of the 6 ft contour). This suggests that the apparent loss of sand was




Dade County, Florida. Beach Nourishment Protect

IL 12 --- ,, Ut aUUn .

principally due to slope adjustment. Additionally, none of the profiles experienced erosion for the
-6 ft to -12 ft depth range indicating continuing profile equilibration.
Table 5
Volumetric Change Characteristics, from R-58 to R-65 for Varioi,, Denth Rinn 1 QR1 -10R

DEP Monument No. Volumetric change, cu yd/ft from 1981 to 1986
Berm to MLW MLW to -6 ft -6 ft to -12 ft
R-58 -31.7" -5.3 +4.6*
R-59 -51.5 -7.8 0.0
R-60 -34.4 -6.1 +6.5
R-61 -16.1 +5.6 +13.9
R-63 -5.2 +11.9 +59.6
R-64 -11.1 +24.1 +12.0
R-65 +42.8 +9.8 +24.3

(+) indicates gain of material; (-) indicates loss of material;
Total volume changes between Bakers Haulover Inlet and Government Cut relative to 1962 have been calculated based on shoreline changes and are presented in Figure 13. The most significant events which occurred in the area between Bakers Haulover Inlet and Government Cut are summarized in Table 6. In 1975, the project area experienced an increase in volume of 2,169,000 m3 due to: (1) the Bal Harbour beach nourishment projects between 1962 and 1975 (181,400 M3),
(2) the Bal Harbour fill of 1,235,000 m3 in July 1975, (3) the extension of the south jetty of Bakers Haulover Inlet and of the north jetty of Government Cut, and (4) the natural recovery of sand following the 1962 Ash Wednesday storm. During the next five years, the first four phases of the nourishment project were completed and the volume change in 1980 was 10,312,800 M3. The apparent significant sand losses which occurred between November 1980 and March 1981 are due in large part to a rapid adjustment of the nourished profiles toward a new equilibrium. The fifth and last phase of the nourishment project was completed in 1982. In the period of time from 1982 to 1992, renourishment was required in some particular areas (Wiegel, 1992):

-20-




N c 2A 0
c 0 o- II
..:0 0 I
8- K z
o w.. . -o S .j . .. . . . -C.. .. . . . .
-, .,,, cn0. I
/ z : !, I =oo ,
C 0 O 0' CD:
: E~ T / c
E = /U
.2 -x~
E4 E
/D 0 r 3 ...
19601962 1965 1970 1975 1980 1985 1990 1995 1998
Time
Figure 13: Total Volume Changes and Volumes Added Relative to 1962 Between Bakers
Haulover Inlet and Government Cut (Based on Shoreline Changes).

a e U/1 0, ( (1, ", I ur nun '()L'( L / c OL c anges
r) I /-,, 171 ; / n I A,'- ; 1, p Descri tion and in / ; I,




I)'id~' Co alo r V .......l / ....... I .. n. .sis of .(c... es

Table 6
List of the Most Significant Events. 3/1962 Ash Wednesday Storm
62-69 Nourishment Projects (213,500 cu yd)
1973 Extension of the North Jetty of Government Cut
7/1975 Extension of the South Jetty of Bakers Haulover Inlet
1975 Bal Harbour Beach Fill (1,625,000 cu yd)
5/1977 Phase I of the Beach Nourishment Project (2,940,000 cu yd)
8/1978 Phase 11 (1,530,000 cu yd)
8/1978 Phase III (3,177,100 cu yd)
5/1980 Phase IV (2,200,000 cu yd)
10/1981 Phase V (2,400,000 cu yd) 1981-1992 Renourishments (460,000 cu yd) 8/1992 Hurricane Andrew
1994 Renourishment (120,000 cu yd)

122,200 m3 (160,000 cu yd) between 63rd and 71"t Streets (T-46 and R-41 Monuments); 53,500 m3 (70,000 cu yd) between 27th and 34th Streets (approximately between R-61 and R-58) were placed after about 6 years, and 175,700 m3 (230,000 cu yd) placed at Bal Harbour Beach after about 15 years. Moreover, 91,700 m3 (120,000) of sand were placed between R-55 and R-56 in 1994 (Dade County Regional Sediment Budget, 1997). The total renourishment has been 624,500 m3 (817,200 cu yd). The combined renourishment rate is 67,700 m3/year (88,600 cu yd/year). Up to 1996, the total volume change is 9,599,000 m3 (12,564,000 cu yd) and the total fill placed is 10,700,000 m3 (14,000,000 cu yd) including the renourishment fills. Therefore, the total volume loss over the 19621996 period is 1,101,000 m3 (1,441,000 cu yd) resulting in an annual volume loss rate of 32,600 m3/year (42,400 cu yd/year).It can be noted that considering only the volume changes from 1992 to 1996 the volume loss is 507,200 m3 (663,800 cu yd) and the annual volume loss rate is 126,800 m3/year (166,000 cu yd/year) which is still lower than the estimated renourishment rate of 145,200

I)a1de Couti.'. Florida. Beach ,Voilrisvhment Projert




m3/year (191,000 cu ydi'year). The total volume change between 1980 and 1996 based on profile changes (Figure 14) is positive while that based on shoreline change is negative (Figure 13). This is due to the fact that not all of the shoreline recession is caused by volumetric losses, but a major part is due to slope adjustment.

x 10,
2.5
2
0
-21.5
(..)
2
0,
0
0.

volume Cnanges
--- Volume Added
E
A 1
Renourishment
-: 5th Phase

- Based on Profile Changes
1990 1995 1996

Figure 14: Total Volume Changes Relative to 1980 Between Bakers Haulover Inlet and
Government Cut (Based on Profile Changes).
Figure 15 presents the volume change per unit length between 1980 and 1996 based on shoreline changes and profile changes. The total volume change (after subtracting the volume added), based on profile changes, is -508,000 m3 (665,000 cu yd). The related volume change rate is -31,700 m3 /year (41,500 cu yd/year), which is consistent with the long-term volume change rate obtained from shoreline data between 1962 and 1996. The volume change rate based on shoreline data of 1980 and 1996 is -186,900 m3/year (244,600 cu yd/year), which is much higher than the previous value and is believed to be an overestimation.

M 1- 11 ( C., 'W .1 1 '-L L ( ... 4"' "a I,; S OLc anges
r) 1" /-- t 1-1 '-r / 1 1, Al, ; 1, f P t T) '; 'i I I ; 11




Dade County Florida Th'o('J, ,Vn,,ra/,,,,~,,t P,,u~,-t

F l .... flo ... .... ,cn._ s._ oj cnnt

80
Based on Profile Changes .1
Based on Shoreline Changes
S60
40 //
- I
1\
20
(n1
0
In 198 E h //Nounshed
>0 20
Bakers Haulover Inlet Government Cut
-40 -1___- __
25 30 35 40 45 50 55 60 6L5 70 75 DEP Monument NoFigure 15: Comparison Between Volume Changes per Unit Length Based on Profile Changes and Shoreline Changes (1980-1996).
Volumetric losses could occur through the south jetty at Bakers Haulover Inlet, through the north jetty at Government Cut, and landward or seaward of the project. Additionally, some settling (consolidation) of the placed material may have occurred. Although some losses may occur through the jetties, this sand transport pathway is believed to be relatively minor. It is known from personal inspection that some of the material placed contained a substantial fraction of silt and clay. This would have been carried out of the active profile by suspension, as was evident by the "milky" color of the water for several years after nourishment. Our interpretation is that the two major contributors of loss are due to fine sediment suspension and consolidation (loss of volume but not of sand). If this interpretation is correct the volumetric loss rates should decrease with time.

-24-




D~adCou'-,n;, Flida Beachf,,'I Noun i1,,nt Pr,,,rt Dese~rint in,a,,d 4naIvis nrlca,n

4.4- Interpretations
4.4.1- Model for Shoreline Displacement
Since the longshore volumetric changes based on profile changes and the shoreline changes are known, it is possible under particular assumptions to determine the percentage of measured shoreline change that is due to profile equilibration process and that is due to material losses. This has been carried out on an average basis considering only the reach between Bakers Haulover Inlet and Monument R-65. After the initial nourishment project has been constructed, and in the presence of following renourishments, the averaged measured shoreline change, Av,, can be expressed as:
y,,,eq+AYL + (1)
where Ayeq is the average shoreline change due only to profile equilibration (no volume change) associated with all previous nourishments, AVL is the average shoreline change due to sand loss and AyR is the average shoreline change due to renourishments (Figure 16). It is noted that Aym, Ayeq and AyL are negative whereas AyR is positive. AyL and AyR can be calculated under the assumption that the profile responds to volume changes (dV) without change of form:
d VL d VR
AyL AyR =- (2)
(h. + B) (h. + B)
where dVL is the average volumetric losses per unit length, dVR is the average renourishment volume per unit length, h. is the depth of closure and B is the berm height. It follows that:
AYeq=,Y,- AYL -AYR (3)
Table 7 summarizes the values of the shoreline changes for different years.

-25-




I, Ayo
-kPost-Nourishment
"hOEquilibrated Pre-Nourishment

a) No Volume Changes

Renourishment
4'Y2 Equlibrated
4Y,, =Yeq+4YL+AYR
b) Volume Changes
Due to Renourishment

c) Measured Volume
Changes

Figure 16: Components of Measured Shoreline Displacements




Dade County, Florida. Beach Nourismunent Proiect

Table 7
Comparison of Average Shoreline Changes Relative to 1980.
Year Ay,,, (n) dVL (ni/m) AYL (n) dV (n/m) AyR (M) Aye (m)
1981 -15.6 -2.3 -0.3 0 0 -15.2
1986 -17.4 -33.6 -4.8 14.2 2.0 -14.6
1992 -24.4 -67.2 -9.6 28.5 4.1 -18.8
1996 -32.4 -89.8 -12.8 35.9 5.1 -24.8
Note: Average Data from Monument R-27 to R-65.
L=12,330 m, h.=5.0 m, B=2.0 m.
Different assumptions have been made: (1) the renourishments have spread out simultaneously over the entire length of the area of interest, (2) the volumetric annual loss rate is referred only to the area between Bakers Haulover Inlet and Monument R-65 (69,000 m3/year), (3) the volumetric annual loss rate, based on profile changes, is constant in time.
4.4.2- Consideration of Shoreline Change Due to Profile Equilibration
The average shoreline change, Ay(t), can be predicted assuming that it follows an exponential form expressed as follows:
Ay(t) = Ay'p +(Ayo Ay'p )e-k(t-ro) (4)
where, k is the "decay parameter", to is the initial time, Ayo is the average shoreline advance immediately after the nourishment or renourishment projects, y 'p is the average shoreline displacment after the profile has achieved total equilibrium. It can be noted that for t=to, Ay(t) is equal to Ayo, and for t tending to tininiy Ay(t,,i,,t) is equal to Ay'p (Figure 17). Equation (4) can be an important tool used to evaluate historic beach fill and to design future projects. The data used to determine k are presented in Table 8. Figure 18 presents the best fit curves of the average measured shoreline changes determined by applying the least square method. It is seen that the values of k

-27-




were determined to be 0.099 yr-' and 0.093 yr-' for all data and omitting the 1981 data which appeared anomalous. A value of k=0.095 yr-' is equivalent to 50% of the profile equilibration occurring in approximately 7 years.
Table 8
Data Used in Determining Decay Parameter, k. Project to Volume added (m3) Ayo (m) Ay ', (m)
Phase 1,2,3,4 1980 8,613,400 137.0 99.7
1" Renourishment 1985 175,700 3.1 -2.0
2n' Renourishment 1990 175,700 3.1 -6.0
3" Renourishment 1994 91,700 1.6 -10.1
Ayo and Ay'p, determined on an average basis from Monument R-27 to R-65. L=13,330 m, h.=5.0 m, B=2.0 m
', Post-Nourishment
~-Equilibrated
Pre-Nourishment
Figure 17: Model for Shoreline Changes due to a Single Nourishment.

Dade Countv orida Beach Nourishment Protect ,,, L 0'. 111 na vs s oL c anges
1) ; ; d 3 1 ; 1.




Dade County, Florida. Beach Nourishment Project

140 ,
a)
130 ........ ........ ; ................................ i ................. ... ..................... ..... ........................ ..
130 ..... :Shoreline Position Data\
E120
< Best Fitting Curve
110 ......... ........ .
k=o.099 yr
100
1980 1982 1984 1986 1988 1990 1992 1994 1996
140 i
b)
130
120
110
1980 1982 1984 1986 1988 1990 1992 1994 1996
Time (year)
Figure 18: Average Shoreline Changes (Best Fitting Curve) for the Reach Between Bakers
Haulover Inlet and Monument R-65. (Panel b) Neglecting the 1981 Data, Which
Appears Anomalous.

Description antd A nalvsis of chances




5- Conclusions
This analysis has shown that the Dade County Beach Nourishment Project has performed very well globally. As of 1996, the required renourishment rate has been less than predicted. The combined rate is 67,700 m3/year (88,600 cI yd/year) compared to the USACE estimated rate of 145,200 m3/year (191,000 cu yd/year) for the beach between Government Cut and Bakers Haulover Inlet. Moreover, the annual volumetric loss for the period from 1980 and 1996 based on shoreline changes is -186,900 m3/year (-244,600 cu yd/year) which is believed to be an overestimation, while the annual volumetric loss, based on profile changes, for the same period is -31,700 m3/year (41,500 cu yd/year) which is much lower than the estimated renourishment rate.
The difference between the two estimations can be due to the fact that the shoreline changes are primarily due to the profile equilibration process. Most of the sand placed during the nourishment project and during the following required renourishments is still inside the active profile zone. The low loss rate based on profile changes can be attributed, in large measure, to the south jetty at Bakers Haulover Inlet and north jetty at Government Cut, which effectively "compartment" the nourished beach. The major contributors of loss are believed to be due to fine sediment suspension and consolidation. If this interpretation is correct the losses should decrease with time.
Globally, two different behaviors can be recognized within the area of interest: (1) the shoreline between Bakers Haulover Inlet and Monument R-65 is receding on an average of 0.80 m/year in part due to profile equilibration and in part due to southerly sand transport, (2) the shoreline between Monument R-65 and Government Cut is accreting significantly.
Locally, two hot spot have been identified, the first in the vicinity of Monument R-36 and the second between Monuments R-55 and R-60. A cold spot is present between Monument R-60 and R-70 and it is likely related to the adjacent hot spot. Studies are in progress to better understand the possible causes of these non-uniform coastal processes.
A model has been developed to represent the profile equilibration process. This model applied to the data between Bakers Haulover Inlet and Monument R-65 indicates that approximately
7 years are required for one-half the profile equilibration.

-30-

Dade Countv, Florida, Reach Nouri.shment Prject

Desqcrition and .,lnalv-sis o~chanves




6- References
Charles, L. L., 1994, "Application of Equilibrium Beach Profile Concepts to Florida's East Coast", UFL/COEL-94/016, Coastal & Oceanographic Engineering Department, University of Florida. Chiu, T. Y.,1981, "Coastal Construction Control Line Study for Dade County, Florida", UFL/COEL-81/006, Coastal & Oceanographic Engineering Department, University of Florida. Coastal Systems International Inc., 1997, "Dade County Regional Sediment Budget ", 84 pp. plus appendices.
Dean, R. G., Dalrymple, R. A., 1991, "Water Waves Mechanics for Engineers and Scientists", World Scientific Press.
Dean, R. G., Dalrymple, R. A., 1998, "Coastal Processes with Engineering Applications ", Class Notes.
University of Florida, Dept. of Coastal & Oceanographic Engineering, 1969, "Beach Erosion and Stabilization Considerations for Bal Harbour Village ", 18 pp. University of Florida, Dept. of Coastal & Oceanographic Engineering, 1969, "A Coastal Engineering Study Related to Stabilization of Lummus Park Beaches ", 20 pp. USA/CESAJ, 1964, "Dade County, Florida Beach Erosion Control and Hurricane Protection Report", 51 pp. plus appendices.
USA/CESAJ, 1981, "Dade County, Florida Beach Erosion Control and Hurricane Surge Protection Project. General Design Memorandum Addendum I". USA/CESAJ, 1984, "Dade County, Florida Beach Erosion Control and Hurricane Surge Protection Project. General Design Memorandum Addendum II", 50 pp. plus appendices.

-31-

Dade Countv, Florida. Reach Nourishment Project




,( 11 ,, or( ec ,, ,men , ,,,,, ,, Fn( D Lescriptlon aind Analusts of changes
USA/CESAJ, 1986, "Dade County, Florida Beach Erosion Control and Hurricane Surge Protection Project. General Design Memorandumn Addendun III", 29 pp. plus appendices.
USA/CESAJ, 1987, "Dade County, Florida Beach Erosion Control and Hurricane Surge Protection Project .General Design Memorandum Addendum IV", 29 pp. plus appendices.
Wang, W., Wang, H., 1987, "Data Compilation of the Historical Shorelines and Offshore Bathymetryfor the Southeast Coast of Florida ", UFL/COEL-87/015, Coastal & Oceanographic Engineering Department, University of Florida.
Wiegel, R. L., 1992, "Dade County, Florida, Beach Nourishment and Hurricane Surge Protection Project", Shore & Beach, Vol. 60, No.4.
Work, P.A., Dean, R. G., 1990, "Shoreline Changes Adjacent to Florida's East Coast Tidal Inlets", UFL/COEL-90/018, Coastal & Oceanographic Engineering Department, University of Florida.
Zheng, J., 1996, "Improved Cross-Shore Sediment Transport Relationships and Models", UFL/COEL-TR/112, Coastal & Oceanographic Engineering Department, University of Florida.

I ..... :_,: ....... J A.__I. _: r t




,ae Coi Iv rl id .ec.... h~e~tPr jctD s rn ...o .................. of....ia v

Appendix A
- Beach Profile Survey Data
Appendix A presents plots of the beach profiles used in this report. The plots are identified by DEP Monument Number. The plots compare surveys of 1969, 1980, 1986, 1992 and 1996 (Table A-i). The surveys extend from the baseline (0 m) to different offshore distances.
Table A-1
List of Available Survey Data.
Date Source Offshore Extent of Data Data Description
on Average (in)
1969 UF Project 6906 400 Beach Profiles
1975 DEP' Shoreline Position
November 1980 DEP 450 Beach Profiles
February 1986 DEP 100 Beach Profiles"*
August 1992" DEP Water line NGVD Beach Profiles**
June 1996 DEP 700 Beach Profiles
DEP Department of Environmental Protection.
.After Hurricane Andrew.
"." Wading Profiles.

Dade Couty. Florida. Reach Noutrishment Project

Descrintion andt lnahwsi~q of rhnnav




I% ....; fl ... .. .4 IF U V. ..N V ,"I .......~e

R-27 6F17
- ---- 1980
1986
2 / 1?" '' : .. . . - 99B
2 / - 1996
0 \ MHW
\ x
-2
-4
-- - .... .-
-6
-8

-100
6
4
2
Ca
0
-2 -

0 100 200 300
R-28

500 600

200 300 400
offshore distance (m)

Figure A-1: Beach Profiles for Monument R-27 and R-28.
A-2

ut e I.I. -, nI o, ,Ct, m,,a inem rot Description andi /natyStS O shan s

L




D IL(f~acf iU i d A l J f hl~<

R-30

0 100 200 300 400 500 600
offshore distance (m)

Figure A-2: Beach Profiles for Monument R-29 and R-30.

. .u. .........s... ,,,u ecr pton an ,naysis3o c anves
R-29
6 I
+- 1969
- + 1975
- -- 1980
2,-1992 2-- 1996
E0 -L MHW
0
-4
-4 N
-6 ....-.. .
-8 I
-100 0 100 200 300 400 500 600 700




Dade Cnuntx, Florida Rear/i iVaurigl,,m',ui Praw,'t

0 100

400 500

R-32

200 300 400
offshore distance (m)

Figure A-3: Beach Profiles for Monument R-31 and R-32.
A-4

R-31
6 ..
4
i 1969
- .*- + 1975
- -- 1980
2 1992
S 1996
0 MHW
-4
-4 -\ x. . . .
-6




V*)LO IJ~ .ALU~r~C3

R-33
4
S1969
- - 1980 1986
2 L~,1111992
. \ ... 996
0 MHW
0
-42
- 4 .. . . . . .
-6 2 r7
-8

0 100 200

200 300 400
offshore distance (m)

Figure A-4: Beach Profiles for Monument R-33 and R-34.

A-5

-100
6
4
2
C
0
-2
-4
-6
-8
-100

Dade Counti, Florida Beach Vonrishm-nt Proie -t-, L on ane / na V.y V OL c an ges




DadeCaunv. For~d Bea/i Niirilmnwir PawetDes'crintini and A tna/vs of nchano','

R-35

+ 1975
.----- 1980
1992
- 1996

N

MHW

0 100 200

400 500

R-36

* 1975
-- --- 1980
S1986
1992
. ------- 1996

XK<-

\ \ MHW
-2 .
\
\
-4
-6 ....
-8 I i
-100 0 100 200 300 400 500 600 70
offshore distance (m)

Figure A-5: Beach Profiles for Monument R-35 and R-36.
A-6

Dade County Florida Beach Nourishment Project




R-37
6
- 1969
# 1975
S- 1980
2 -1992
- - 1996
E 0_ MHW
C
,0 \
(2
> 2 ......... . . .. . ... ... .. .. ..
S-2
-4
-6
8
-100 0 100 200 300 400 500 600 700
R-38
6I I I I
4
4 . . . . . . . . . . . . . ..... .. ... .. . . .... . . . .. . . . . . . . . . . . . . . .:. . . . . .
2
o MHW
0.2
C
- 4 -. .. . .
-6
-8
-100 0 100 200 300 400 500 600 700
offshore distance (m)
Figure A-6: Beach Profiles for Monument R-37 and R-38.




a( e t or a n ur v n ,o, escrption an Ana Is

6 4
2
0
-2
-4
-6
-8
-100

* 1975
.---- 1980
1992
. 1996

2~~ N

.0 MHW
0
-2
\
N
-4 N
-6
-8
-100 0 100 200 300 400 500 600 70,
offshore distance (m)

Figure A-7: Beach Profiles for Monument R-39 and R-40.

A-8

R-39

0 100 200 300 400 500 600

R-40

D i d l




(JUi t (oury V, ora, venan n un n ,,m ro, ec, escrptoJU n IJ(L an L VI s sLC afln

* 1975
----- 1980
1992 1996

MHW
0 U
-2
-4
-6 ---8
-100 0 100 200 300 400 500 600 70

R-42

MHW

\ ,, . .

200 300 4
offshore distance (m)

Figure A-8: Beach Profiles for Monument R-41 and R-42.

A-9

0
go
-2
-4
-6

D i i d A l h




b
4
- 1969
+ 1975
- ..... 1980
2 . 1992
-. 1996
0 + MHW
-2
-4
S-6
- I.. I I

0 100

600

7

R-44

200 300 400
offshore distance (m)

Figure A-9: Beach Profiles for Monument R-43 and R-44.
A-10

00

flnIa ('n,,,n,, Plnri,/n Po,,rI, AfnuricJ,,,,ent Prnort

Dade 1--wav orida Beach Nourishment Pro;--t LL I L'. L, anzn'sc ; ti,. -1 J. / i 11

L




Dade County. Florida. Beach Nourishmunent Proiect

Descriatian and A ,ialv~'v~ n/c/mn ups-

1980
1 988!
1992
2 .... ; F 7g98 ..
0 : tii MHW
~0
-4
-6 .....
-8 I 1 2 0 I I
-100 0 100 200 300 400 500 600 7C

R-46
I I
. ..... ... ... ......... . . . . . . . . . . . . . . . !. . . 1 9 59 9 l
1969
* + 1975
----- -- -1980
- 1992
-- .. 1996
SMHW
N *\

0 100 20

0 300 400
offshore distance (m)

Figure A-10: Beach Profiles for Monument R-45 and R-46.
A-1I

-8
-10

0

I I I I I I I

,i i r .. .. . es r t o ..... .... .... ... .... a es....,




Dade flnintv Florida Reach Naitridiawni Prawet

R-47
6
4
+-+ 1969
-- 1975
/ ..- .. 1980
2 1992
- -1996
0 MHW
-2
-4
-6
-8

0 100

400 500

R-48

0 300 400
offshore distance (m)

Figure A-11: Beach Profiles for Monument R-47 and R-47.
A-12

Dade Countv Florida Beach Nourishment Protect n-, 'i I I I ; 1.
'U- -" ""' '"' V-V S OLc qn( es




R-49
6
4
19675
2 ---. 1980
1996
2 1... ...... ... 99
-. 1996
0 MHW
-2
-4 ---6
O I I

0 100 200 300
R-50

500 600

-8 I 1 I I
-100 0 100 200 300 400 500
offshore distance (m)

600 700

Figure A-12: Beach Profiles for Monument R-49 and R-50.

A-13

if) '9 C rLL4rL~~3

a till 1. r eac urs men, toLec, escr p on an II(I I-; S OLc anQeS
f) I- /-- '. E'/,, ',I- n 1, hf- ; 1, 13. n ; .* 4 1 / ; 1.




R-51
6
4
1975
- 1980
1986
2- 19
2- 1996
0 MHW
0
>- .. 7i. .. .... .. .
~ 2
-4
-6
-8
-100 0 100 200 300 400 500 600 700
R-52
6I
4 ...... 1969
* 1975
- --- 1980 1992
2 ... .......... ~ ~~~~~~~~... .... : . . . . . . . . . - 9 6 1
2 1996
0 MHW
ON
-2 .... ... ............ ... .y .............. .. .. ........ ..........
-4
- 6 . .. ..... .... ...... .
-8
-100 0 100 200 300 400 500 600 700
offshore distance (m)
Figure A-13: Beach Profiles for Monument R-51 and R-52.
A-14

Dade Countv. Florida. Beach Nourishment Proiect




D i i d t A

L

... . ............ .. uescr pton an( na, io 1YV;' O chanzes
R-53
6
4
+-+ 1969
+ +- 1975
- 1980 2 1992
- 1996
0 MHW
0
-4
-6 -.
-8
-100 0 100 200 300 400 500 600 700
R-54
......................... ... ...... ............. ... ....... .... .................. .... ......... .
61
1969
1975
- -I- 1980 1996
2- 1992
-. 1996
0 MHW
-2
-4
-6
-8 I I
-100 0 100 200 300 400 500 600 700
offshore distance (m)
Figure A-14: Beach Profiles for Monument R-53 and R-54.
A-15




D eo F d Ba N r et eDecrintmn ndAn i fcn

6
4
2
0
o
.
( -2
-4

0 100

300 400 500
R-56

200 300 400
offshore distance (m)

Figure A-15: Beach Profiles for Monument R-55 and R-56.
A-16

-[
I T
i i 1969 S1975
- -1980 1992
- -. 1996
MHW

+
+ ',

Dade County. Florida. Beach Nourishment Proiect




Dade Couniy Florida Beach Nourishment Proiect iv' iuescrpton an nay Vss rLts

R-58

200 300 400
offshore distance (m)

Figure A-16: Beach Profiles for Monument R-57 and R-58.

A-17

D i i d A l




Dade Countyv. Florida. Beach Nourishment Proiect

Dpscrintinn and AnnIv'.~k nfrIin,,a,-'~~

R-59
6 I I
4 -.. .. 1969
S* 1975
- 1980
__.__ ~1992 2- 1996
..I
MHW
0
-2
-4
-6
-8
-100 0 100 200 300 400 500 600 700
R-60
4 \---- 1969
# 1975
- 1990 19969
2 1996
199
1MHW
0
CO
-2
-4
-6
-8 j I
-100 0 100 200 300 400 500 600 700
offshore distance (m)
Figure A-17: Beach Profiles for Monument R-59 and R-60.

A-18




fbi/a ('n,,,,tv, PtnriAn florin, Vn,,rvkrnanp D,.niorv

L

A-19

van, aones q aeve un, ouce a v we sutrarn a vtc s v cru s onr anc au VSl Uf~ offifles
R-61
6I
4 i* 1969
* + 1975
- --.. 1980
2 AI X 1...1 9 9 2
2 / -- .- 1996
JN
0 MHW
0
-2
-4 .
-60
-8
-100 0 100 200 300 400 500 600 700
R-62
-6
4
2
0MHW E -2
-4
-6
-8 I I I
-100 0 100 200 300 400 500 600 700
offshore distance (m)
Figure A-18: Beach Profiles for Monument R-61 and R-62.




A-20

R-63
6
4 in196
1975
1980
1985
__:_ _1_992 2 - 1999
CJ
0MHW
-4A
-6
-8
-100 0 100 200 300 400 500 600 700
R-64
4 --+ 1969
* 1975
---- 1980
1992
2 .. .. ... .. . ...... . ..... . .. . . . 1 9
2 1996
+\ HW
0
S-2
- 4 . . . . . . . . . .. . . .... . . . . . .
N
-6
-8 I I
-100 0 100 200 300 400 500 600 700
offshore distance (m)
Figure A-19: Beach Profiles for Monument R-63 and R-64.




Dadel Couint Florida BeachI Nourish~ment Proiect flpvcri nhn and Anal sis oncan'es

R-65

6
4
2
o
-
-4
-6
-8
-100
6
4 2 0o
.
S-2
-4
-6

200 300 400
offshore distance (m)

R-66

Figure A-20: Beach Profiles for Monument R-65 and R-66.

A-21




0 100 200

400 500

-100 0 100 200 300 400 500 600
offshore distance (m)

Figure A-20: Beach Profiles for Monument R-65 and R-66.

A-21

I
. 1969 S 1975
----- 1980
S1992 1996
\\ MHW N)
. . . . : I - . . . . . . . . . . . : . . . . .

-8
-100
6
4
2
0o
~ 2

a U11 I, ,, e ,, e a, w s men roLec escr p, on ant na VS S OLc anges
n 'I, /-- ; I )? 1. A/- .; 1. JD I n ; ; I I I ; 1.




florla fn,,n t,, P/nr,,1,, floor1, AJn,,r, vi, nnnt Prajort

L

A-22

R-67
6
4 1969
+ 1975
S 1980
1992 S 1996
MHW
0
-4 -_-. .. - -2
-6 ............... ................ ................ ...... ......... -- .--7 2 :-4
-6.
-8
-100 0 100 200 300 400 500 600 700
R-68
6 I I I
4
24 \ _, .. : .. . .. . . i ". . .. . .
Fiur A-2: BecrflsfrMnmn R-7ad: -8
,J
2- \
MHW
C
-2
-4 .
-6 .
-8 I r
-100 0 100 200 300 400 500 600 700
offshore distance (m)
Figure A-21: Beach Profiles for Monument R-67 and R-68.




Dade County. Florida Beach tnurihn ,t i

L.'e~,UrLvA IOfl (ma Afl(mIVSIS 01 cflanzes

A-23

, .escription and Analysis of changes
R-69
6 I
40
6 1969
/* 1975
- -- 1960
2
2 ----- 1996
V\,
0 -MHW
-2
R-70
6
4 . . .. . . ; . . . . . . . . . . . .. . . . . . . . . . . .... . . . . . . . . . .
4 -
1969
1975
-. 1980
2- -, 1992
.) - -1996
E 0 MHW
VE N
0N
-
: _: : . . . . . . . . . . . . . . . __ . . . .1. / -. .
-6N
--_ i__
-8
-100 0 100 200 300 400 500 600 700
offshore distance (m)
Figure A-22: Beach Profiles for Monument R-69 and R-70.




4

A-24

.... r a L if ltf v r o[c't Description and Analysis of changes
R-71
6
4
1969
, 1975
- 1980
21992
- 1996
0 MHW
0
-2
-4
-6
-8 I I
-100 0 100 200 300 400 500 600 700
R-72
6 I
4
: 1975
-- '19809
2 1996
E 0 MHW
0
-2
-4
-6
-8
-100 0 100 200 300 400 500 600 700
offshore distance (m)
Figure A-23: Beach Profiles for Monument R-71 and R-72.




lJah' ('nunIv' Finrida Rparl, A/n,,rid,,npnt Prns-,,-t

A-25

R-73
4
. 1969
+ 1975
1980 27 .1992
S- - 1996
MHW
0
-4
-6
-100 0 100 200 300 400 500 600 700
R-74
6
4
2 .. ........ .... ... ...... .. ........... .................. ..
0 MHW
0
2
2 -.. N -... . ................. ..........!...... .........." ................. ... ... ...... ..
-4 N
8
-100 0 100 200 300 400 500 600 700
offshore distance (m)
Figure A-24: Beach Profiles for Monument R-73 and R-74.




Dade Cou,,iv Forida Beach Nourishment Proiect L ,,,'~ an naj s s rotS n

Appendix B
- Summary Plots of Longshore Distribution of Shoreline and Volume Changes
Appendix B provides plots of the longshore distribution of: (1) Annual Rate of Volume Change per Unit Beach Length, (2) Annual Rate of Shoreline Change, (3) Shoreline Change. The plots are listed for different time intervals.




IWLiLJ~& LtttCL flflt4S VitO (fl C ~Wfl

Annual Rate of Volume Change per Unit Longshore Distance

(80-96) b) Total: -44,616 m3tyr

Mi
+

N

25 30 35 40 45 50 55 60 65 70 75
(92-96) c) Total: -126,800 m3/yr
-50
25 30 35 40 45 50 55 60 65 70 75
500 (80-81) d) Total: -3,204,900 m3/yr
E -500-1000
25 30 35 40 45 50 55 60 65 70 75
DEP Monument No.

Figure B-1: Volume Changes for Periods: 1962-1996 (Panel a), 1980-1996 (Panel b),
1992-1996 (Panel c), 1980-1981 (Panel d).
All Volume Changes Based on Shoreline Changes.

B-2

50

50
-50
-50

a un v, ,, ( ,, a, ur s men roLec escru on an na vs OU anQes
1) '1" /-- jCI ; / /? 1, Al- ; 1. 13 1 T) 4 A I ;- 11




4)
E

Figure B-2: Volume Changes for Periods: 1981-1996 (Panel a), 1981-1992 (Panel b),
1980-1992 (Panel c), 1975-1996 (Panel d).
All Volume Changes Based on Shoreline Changes.

B-3

Annual Rate of Volume Change per Unit Longshore Distance 100
(81-96) a) Total: 41,435 m3/yr
50
25 30 35 40 45 50 55 60 65 70 75
100
(81-92) b) Total: 102,610 m3/yr
50
25 30 35 40 45 50 55 60 65 70 75
100
(80-92) c) Total: -17,223 m3/yr
50
0
-50
25 30 35 40 45 50 55 60 65 70 75
DEP Monument No 100
(75-96) d) Total: 353,820 m3/yr
50
50
25 30 35 40 45 50 55 60 65 70 75
DEP Monument No.

E,

CE

W 101 V, or I ur s men roL- -11 v I'll "" 2 OLc an s
r) 1, f-- 1 ;,4- )? 1, A[- ; 1, T) I r) ; t; 11 11 / ; 11




flat/p Cn,,ntv F/aria',, Roar/i Nnurid,,nont Pr,-,io,-t

Annual Rate of Shoreline Change

U
25 30 35 40 45 50 55 60 65 70 7
15
10
1 80-96) b)
0
-10 I
25 30 35 40 45 50 55 60 65 70 7
10
(92-96) c)
5
0
-5
1 0 . .. I . .

30 35 40 45 50 55 60 65 70 75

-i
25
100 50 (8
0
-50
-100-

DEP Monument No.

Figure B-3: Annual Rate of Shoreline Changes for Periods: 1962-1996 (Panel a), 1980-1996
(Panel b), 1992-1996 (Panel c), 1980-1981 (Panel d).
B-4

(62-96)

na S OLC ankel 1).- t; d I / ; 1.
Dade Countv Floridiz Beach Nourishment Proiect

1U

I u

_H

F




V~l~t f/~lLV. ~t,' Itt flCL Ct H IvtJt~tf~lH l Stt (Jt U LI l'Z3C~ [L~l tCL/ lK1 (VLLH lf~tflUl .5)

Annual Rate of Shoreline Change

(81-96) a)
L

25 30 35 40 45 50 55 60 65 70 75
20
(81-92) b)
15
i 5 .. .....
0
-5
25 30 35 40 45 50 55 60 65 70 75
20 1 1 1 1 ,
(80-92) c)
1 0 .. . . . .. . . . . .
15
10
-51
25 30 35 40 45 50 55 60 65 70 75
DEP Monument No. 20 1
(75-96) d)
15
1 0
-5
25 30 35 40 45 50 55 60 65 70 75
DEP Monument No.

Figure B-4: Annual Rate of Shoreline Changes for Periods: 1981-1996 (Panel a), 1981-1992
(Panel b), 1980-1992 (Panel c), 1975-1996 (Panel d).

B-5




Dade (onty, Flori onrI AJn,,richmont P tnion

Shoreline Change 200
10-(62-96) a) 100
5 0 .. .. . . .
0
-50
25 30 35 40 45 50 55 60 65 70 75
200
(80-96) b)
100 .:"
0
100
25 30 35 40 45 50 55 60 65 70 75
30 ,
(92-96) c) 20
-10
10
-20
-30
25 30 35 40 45 50 55 60 65 70 75

DEP Monument No.

Figure B-5: Shoreline Changes for Periods: 1962-1996 (Panel a), 1980-1996
(Panel b), 1992-1996 (Panel c), 1980-1981 (Panel d).
B-6

LIJL&W& WILL CflLU$VJ(J (ii tAIWL~tt3

Dad Cont srd B e- h ro ec. ,o,., on an nmanc I S ,,any.e




flacrrintinn nnr/ 4 nnh,,c'iv n(rla,,ryoc'

E

Shoreline Change
200
(820 1-96) a) 100
0
100

25 30 35 40 45 50 55 60 65 70 75
200
(81-92) b) 100
25 30 35 40 45 50 55 60 65 70 75
200
100
20- (092oc I I
25 30 35 40 45 50 55 60 65 70 75
DEP Monument No.

30 35 40 45 50 55 60 65 70
DEP Monument No.

Figure B-6: Shoreline Changes for Periods: 1981-1996 (Panel a), 1981-1992 (Panel b),
1980-1992 (Panel c), 1975-1996 (Panel d).
B-7

Dade Count Florida Beach Nourishment Proiect Qesri-i n--dA-qI ;-f 1-