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 Front Cover
 Title Page
 Table of Contents
 Advance summary
 Main
 A series of 18 photographs of Boca...
 Sediment budget methodology
 Plots of selected profiles corresponding...














Group Title: Review of selected east coast Florida inlets Boca Raton Inlet, Florida Evaluation of coastal processes and management practices and development of
Title: Review of selected east coast Florida inlets Boca Raton Inlet, Florida Evaluation of coastal processes and management practices and development of
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Title: Review of selected east coast Florida inlets Boca Raton Inlet, Florida Evaluation of coastal processes and management practices and development of
Series Title: Review of selected east coast Florida inlets Boca Raton Inlet, Florida Evaluation of coastal processes and management practices and development of
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Table of Contents
    Front Cover
        Front Cover
    Title Page
        Title Page 1
        Page i
    Table of Contents
        Page ii
        Page iii
        Page iv
        Page v
    Advance summary
        Page 1
    Main
        Page 2
        Page 3
        Page 4
        Page 5
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
        Page 13
        Page 14
        Page 15
        Page 16
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        Page 18
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        Page 23
        Page 24
        Page 25
        Page 26
        Page 27
        Page 28
        Page 29
        Page 30
        Page 31
        Page 32
        Page 33
        Page 34
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        Page 37
        Page 38
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        Page 40
        Page 41
        Page 42
        Page 43
        Page 44
        Page 45
        Page 46
    A series of 18 photographs of Boca Raton Inlet 1936 to 1995
        Page 47
        Page 48
        Page 49
        Page 50
        Page 51
        Page 52
        Page 53
        Page 54
        Page 55
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        Page 60
        Page 61
        Page 62
        Page 63
        Page 64
        Page 65
        Page 66
    Sediment budget methodology
        Page 67
        Page 68
        Page 69
        Page 70
    Plots of selected profiles corresponding to long profile monuments for earliest survey from R-189 in Palm Beach County to R-55 in Broward County
        Page 71
        Page 72
        Page 73
        Page 74
        Page 75
        Page 76
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Full Text


UFL/COEL -2004/007


REVIEW OF SELECTED EAST COAST FLORIDA INLETS
BOCA RATON INLET, FLORIDA EVALUATION OF
COASTAL PROCESSES AND MANAGEMENT
PRACTICES AND DEVELOPMENT OF SEDIMENT
BUDGETS



by


Robert Dean
William McDougal
and
Andrea Smith



June 28, 2004




Submitted to:

Bureau of Beaches and Coastal Systems
Department of Environmental Protection
Tallahassee, FL 32399

Coastal & Oceanographic Engineering Program
Department of Civil & Coastal Engineering
575 Weil Hall* P.O.Box 116580 Gainesville, Florida 32611-6580

UNIVERSITY OF
FLORIDA







UFL/COEL -2004/007


REVIEW OF SELECTED EAST COAST FLORIDA INLETS
BOCA RATON INLET, FLORIDA EVALUATION OF
COASTAL PROCESSES AND MANAGEMENT
PRACTICES AND DEVELOPMENT OF SEDIMENT
BUDGETS




by


Robert Dean
William McDougal
and
Andrea Smith


June 28, 2004




Submitted to:

Bureau of Beaches and Coastal Systems
Department of Environmental Protection
Tallahassee, FL 32399










REVIEW OF SELECTED EAST COAST FLORIDA INLETS
BOCA RATON INLET, FLORIDA
EVALUATION OF COASTAL PROCESSES AND
MANAGEMENT PRACTICES AND
DEVELOPMENT OF SEDIMENT BUDGETS




June 28, 2004


Prepared by:

Robert Dean
William McDougal
Andrea Smith






Submitted to:

Bureau of Beaches and Coastal Systems
Department of Environmental Protection
Tallahassee, FL 32399






Submitted by:

Department of Civil and Coastal Engineering
University of Florida
Gainesville, FL 32611-6590








TABLE OF CONTENTS

ADVANCE SUMMARY .............................................. 1

1.0 INTRODUCTION .................................................. 2

2.0 THE SYSTEM OF INTEREST ....................................... 3

2.1 General ................................................... 3
2.2 Boca Raton Inlet .............................................. 3

3.0 DATA USED IN ANALYSIS ......................................... 7

3.1 SurveyData ...................................................... 7
3.2 Nourishments Conducted ........................................... 7
3.3 Sand Bypassing at Boca Raton and Hillsboro Inlets ...................... 9

4.0 CORRECTIONS/MODIFICATIONS TO SURVEY DATA .................. 12

4.1 Attempts to Correct Survey Data for Non-Closure ....................... 12
4.2 Correction for Monument Relocation .................................13

5.0 UNCERTAINTIES IN DEVELOPING SEDIMENT BUDGETS .............. 15

5.1 General ................................................. ..... 15
5.2 Volume Changes ............................................ 15
5.3 Bypassing Quantities by Dredge .......................... ....... 16
5.4 Natural Bypassing Quantities ................ .................. 16
5.5 Nourishment Volumes ........................................ 16

6.0 GRAPHICAL PRESENTATION OF RESULTS........................... 17

6.1 Total Changes in Cumulative Volumes and Planform Areas
Within Segments .............................................. 17
6.1.1 Changes in Cumulative Volumes ........................ 17
6.1.2 Changes in Total Cumulative Beach Area Within Segments ... 19
6.2 Longshore Distributions of Volume and Shoreline Change ............. 19
6.3 Sediment Budgets ...... ..................................... 22

7.0 RESULTS AND INTERPRETATION ................................... 24

7.1 Cumulative Plan Area and Volume Changes With Time
for the Three Sections .......................................... 24
7.1.1 Segment 1 ................... ................... . 24
7.1.2 Segment 2 ................... ....... ...... .. . . .. 26
7.1.3 Segm ent 3 .. .......................... .. ..... . . 28









7.2 Distributions and Cumulative Distributions of Shoreline and Volume
Changes in Various Segments ... ........................... 31
7.2.1 General.............................................. 31
7.2.2 Early Time Period: Mid 1970's to Early 1990's ......... 31
7.2.2.1 Shoreline Changes, Early Time Period ........ 31
7.2.2.2 Volume Changes, Early Time Period ......... 33
7.2.3 Later Time Period .............................. 35
7.2.3.1 Shoreline Changes, Later Time Period ........ 35
7.2.3.2 Volume Changes, Later Time Period ......... 35

7.3 Sediment Budgets ............................................ 38
7.3.1 General ............................................. 38
7.3.2 Sediment Budgets For Each of Three Segments............... 38
7.3.3 Global Sediment Budgets ............................... 40


8.0 RECOMMENDED SEDIMENT BUDGET PROTOCOL FOR BOCA RATON
INLET .......................................................... 41

8.1 General ................................................... 41
8.2 Recommended Sediment Budget Protocol for Boca Raton Inlet .......... 42

9.0 POSSIBLE FUTURE EFFORTS ......................................42

9.1 Deerfield Beach Groin Field ........................................ 42
9.2 Bar Bypassing Around Boca Raton Inlet ......................... 43

10.0 SUMMARY AND CONCLUSIONS ..................................44

10.1Summary .................................................. 44
10.2 Conclusions ............................................... 45

11.0 ACKNOWLEDGEMENTS ......................................... 45

12.0 REFERENCES ................................................... 46

APPENDIX A: A SERIES OF 18 PHOTOGRAPHS OF
BOCA RATON INLET: 1936 TO 1995 ...............................47

APPENDIX B: SEDIMENT BUDGET METHODOLOGY ..................... 67

APPENDIX C: PLOTS OF SELECTED PROFILES CORRESPONDING TO
LONG PROFILE MONUMENTS FOR EARLIEST SURVEY
FROM R-189 IN PALM BEACH COUNTY TO
R-55 INBROWARD COUNTY ..............................71












LIST OF FIGURES

Figure Caption Page

1 Aerial Photograph of Boca Raton Inlet. November 6, 1995 ......... 2
2 Representation of System of Interest as
Three Shoreline Segments ................................ 4
3 Modifications to Boca Raton Inlet System. (From CPE, 1992) ...... 6
4 Schematic of System Considered and Distances of Relevant Features
South of Monument R-189 in Palm Beach County ............. 8
5 Historical Bypassing Characteristics at Boca Raton Inlet ......... 10
6 Historical Bypassing Characteristics at Hillsboro Inlet ............ 11
7 Survey Procedure With Wading Profiles Conducted at Low Tide
and Boat Profiles Conducted at High Tide ............... 12
8 Four Profile Surveys at Monument R- 15 in Broward County ....... 14
9 Cumulative Differences in Elevation Beyond 20 foot Depth Distance.
Monument R-15 ................ .................. 14
10 Corrected Profiles at Monument R-15 in Broward County .......... 15
11 Total Volume Change With Time in Segment 2
and Cumulative Nourishment in Segment 2 ............... 18
12 Volume Change in Segment 2 Minus Nourishment............... 18
13 Total Plan Area Change in Segment 2 ......................... 19
14 Distributions of Volume Change Rates and Cumulative
Change Rates For Period: Early 1990's to Early 2000's.
Calculations to 20 feet Depth Distance Offshore ................ 20
15 Volumetric Sediment Budgets For Early and Later Time Periods .... 23
16 Cumulative Plan Area Changes in Segment 1 ................. 24
17 Cumulative Volume Changes in Segment 1
and Nourishment History ............................ 25
18 Cumulative Volume Changes Minus Nourishment in Segment 1 ..... 25
19 Cumulative Plan Area Changes in Segment 2 ................... 27
20 Cumulative Volume Changes in Segment 2
and Nourishment History .............................27
21 Cumulative Volume Changes Minus Nourishment in Segment 2 ..... 28
22 Cumulative Plan Area Changes in Segment 3 ................... 29
23 Cumulative Volume Change in Segment 3
and Nourishment History .......................... 29
24 Cumulative Volume Change Minus Nourishment in Segment 3 ...... 30
24 Distributions of Shoreline Change Rates and Cumulative
Change Rates for Period: Mid 1970's to Early 1990's ............. 32








26 Distributions of Volume Changes and Cumulative Change Rates for
Period: Mid 1970's to Early 1990's.
Calculations to 20 feet Depth Distance Offshore ............. 34
27 Distributions of Shoreline Change Rates and Cumulative
Change Rates for Period: Early 1990's to Early 2000's ............ 36
28 Distributions of Volume Change Rates and Cumulative Change
Rates for Period: Early 1990's to Early 2000's.
Calculations to 20 feet Depth Distance Offshore ............ 37
29 Volumetric Sediment Budgets For Early and Later Time Periods ..... 39
30 Typical King Pile Groin Installation.
Note: Rubble Mounds at Ends of Groins Not Shown ......... 43



LIST OF TABLES

Table Caption Page

1 Major Developments at Boca Raton Inlet
(From CPE, 1992) ................ .................. 5
2 Estimates of Net (Southward) Longshore Sediment Transport ........ 5
3 Survey Data Used in This Study ............................... 7
4 Nourishments of Influence to Segments and Time Periods Analyzed.. 9
5 Results of "Global Sediment Budget" Analysis ................... 41









ADVANCE SUMMARY


Available survey data were analyzed to determine the natural sand transport
characteristics in the vicinity of Boca Raton Inlet for the purpose of developing a
sediment budget for this inlet. This inlet has a weir section located in the updrift (north)
jetty and a dedicated dredge which transfers sand to the downdrift beaches. This
bypassing is supplemented by bypassing from the ebb tidal shoal on an infrequent basis
(average of 8 years). The objective in the development of a recommended sediment
budget leading to sediment management practices is to mimic, to the degree practical, the
natural flows of sand past an inlet so that the natural processes are transparent to the
presence of the inlet. In the development of sediment budgets it is necessary to recognize
that the natural flows of sand can vary substantially from year to year. Thus a sediment
budget should not incorporate a rigid requirement for an annual bypassing rate, but
should provide a means to track and respond to the relative volumetric changes on the
immediate updrift and downdrift beaches. The objective should be to achieve equity
through balancing these volume changes.

The time period of interest encompassed in this effort was from the mid 1970's to the
most recent surveys. During this period, a total of four nearly complete surveys were
available in Palm Beach County and nine such surveys were available in Broward
County. A total distance of approximately 18 miles was considered extending from
approximately 7 miles north of Boca Raton Inlet to 5 miles south of Hillsboro Inlet. The
encompassed system was considered as three segments with Segment 1 north of Boca
Raton Inlet, Segment 2 the approximate 5 miles between Boca Raton Inlet and Hillsboro
Inlet and Segment 3 south of Hillsboro Inlet. The nourishments both inside and adjacent
to the system were accounted for as were the bypassing at the two inlets.

These survey and other data were analyzed and the results presented in several formats to
aid interpretation. The formats which were most related to determination of a sediment
budget considered two time periods: An "Early Period" from Mid 1970's to Early 1990's
and a "Later Period" from Early 1990's to Early 2000's. During the Early period it was
found that the volume in Segment 2 increased at a rate of 13,300 yd3/year with no
nourishment in this segment during this period. During the Later period when the survey
data are expected to be more accurate, Segment 2 increased in volume at a rate of 77,600
yd3/year above the average rate of nourishment and hydraulic bypassing additions. This
could be due to either more natural bypassing via the ebb tidal shoal at Boca Raton Inlet
and/or differences between the actual and reported hydraulic bypassing rates at the two
inlets. The conclusion is that the volume in Segment 2 has been increasing over the total
time period examined.

A sediment budget protocol for Boca Raton Inlet is recommended which includes: (1)
Maintain a hydraulic bypassing capability of 100,000 yd3/year which includes bypassing
from the ebb tidal shoal as needed, (2) Conduct annual surveys to determine the volume
change differences north and south of the inlet, and (3) During the following year,
respond to these differences through bypassing modifications.








REVIEW OF SELECTED EAST COAST FLORIDA INLETS
BOCA RATON INLET, FLORIDA
EVALUATION OF COASTAL PROCESSES AND
MANAGEMENT PRACTICES AND
DEVELOPMENT OF SEDIMENT BUDGETS



1.0 INTRODUCTION

The primary objective of the project on which this report is based is to develop a
recommended sediment budget protocol for Boca Raton Inlet, recognizing its inherent
interannual variability. Although there are several approaches that could be utilized
toward this objective, the generally extensive survey data along the Florida shoreline
make the use of such data the most credible and appropriate approach. Although the
focus is on Boca Raton Inlet, Hillsboro Inlet and beaches to the south of Hillsboro Inlet
have been included to provide a broader base and a basis for checking the validity of
some of the volume changes. Figure 1 presents a 1995 photograph of Boca Raton Inlet.


Figure 1. Aerial Photograph of Boca Raton Inlet. November 6, 1995.








2.0 THE SYSTEM OF INTEREST


2.1 General

The system of interest to this effort is defined as extending from Monument R-189 in
Palm Beach County to Monument R-55 in Broward County, a total distance of 93,810
feet, approximately 18 miles. As shown in Figure 2, this system is naturally represented
as three segments with Segment 1 north of Boca Raton Inlet, Segment 2 between Boca
Raton Inlet and Hillsboro Inlet and Segment 3 south of Hillsboro Inlet.

2.2 Boca Raton Inlet

Boca Raton Inlet is a natural inlet that is now stabilized by a north jetty of some 610 feet
in length and a 490 feet long south jetty (both approximate and relative to the south
shoreline). In its natural condition, this inlet was alternately open and closed. The inlet
served to relieve elevated water levels in Boca Raton Lake following periods of high
rainfall; however, during extended periods of low rainfall, the inlet was closed by natural
sediment transport processes.

The major events leading to the modern day stabilized Boca Raton Inlet are summarized
in Table 1 and Figure 1 has presented a reasonably recent photograph of Boca Raton
Inlet. In its current form, Boca Raton Inlet is stabilized by north and south jetties with a
weir of 65 feet in the north jetty and an 8 inch cutter head dredge which serves to
transport sand to beaches south of the inlet. Figure 3, from Coastal Planning and
Engineering (CPE, 1992) presents a summary of modifications made to Boca Raton Inlet
and a recent configuration. This figure does not reflect a recent 50 feet seaward location
of the weir section in the north jetty.

Various estimates exist of the net annual longshore sediment transport at Boca Raton
Inlet. These estimates are summarized in Table 2. The Walton (1976) estimate is believed
to be too large as a consequence of the effect of the Gulf Stream increasing the wave
heights observed from ships which were used to calculate sediment transport.

Appendix A presents 18 historical aerial photographs extending from 1936 to 1995.








-Qm
dV/dt


QNOUR


dV/dt


QNOUR


dV/dt

QNOUR


Segment 1


Segment 2








Segment 3


- oUT


Figure 2. Representation of System of Interest as Three Shoreline Segments.
Dates Shown are for "Early" Time Period.


Boca Raton In









Hillsboro Inl


I








Table 1. Major Developments at Boca Raton Inlet
(From CPE, 1992)


Date(s) Development
1925 1926 Inlet improvement by dredging. Inlet oriented to southeast
1930 1931 Two jetties constructed approximately perpendicular to shoreline. Inlet
shoaling continued, requiring periodic dredging.
1940's Air Force provided funding to maintain inlet open, but was unsuccessful.
1952 Jetties repaired and inlet dredged.
1960 Report by Coastal Engineering Laboratory of the University of Florida
(CEL/UF) recommended jetty extension and dedicated dredge to maintain
inlet open and navigable.
1972 City of Boca Raton purchased small dredge and tug for purpose of bypassing
sand.
1975 City extended jetties and made repairs using CEIJUF design for guidance.
North jetty extended 180 feet and included a section of concrete filled bags
which could be removed to form a weir section.
1980 Concrete bags removed to form 65 feet weir section.
1980's Dredge capabilities increased to improve transfer from offshore shoal.
1985 Offshore shoal dredged: 221,000 yd3 and placed on south beach.
R-223 to R-225.6
1996 Offshore shoal dredged: 220,000 yd' and placed on south beach.
R-223 to R-225.6
2002 Offshore shoal dredged: 343,000 yd3 and placed on south beach.
R-223 to R-227.7


Table 2

Estimates of Net (Southward) Net Longshore Sediment Transport

Source of Estimate Estimated Net Longshore Sediment Transport (yd3/yr)
U. S. Army Corps of Engineers 150,000
(1955)
Walton (1976) 280,000
Coastal Planning and 121,500
Engineering (1992) (This estimate is for the period: 1985 to 1991).














0

o "



o
C1

0
d &
o 3



0
/ 0
aC
08










0




i-y
0)


---APPROXIMATE MEAN HIGH
WATER SHORELINE


N



O 100 200
V 65 FT. WEIR 0 0 00

SCALE IN FEET


UlG.A hA IUN INLtI L--180 FT. NORTH JETTY
EXTENSION (1975)




SOUTH JETTY REINFORCED WITH BOULDERS AND
CONCRETE BAGS ALONG 540 FT. LENGTH (1975)


DISCHARGE FOR DREDGE SAND
FROM INLET MAINTENANCE

SOUTH JETTY REINFORCED WITH BOULDERS
ALONG 160 FT. LENGTH (1980)


ATLANTIC


OCEAN


--- APPROXIMATE MEAN HIGH
WATER SHORELINE









3.0 DATA USED IN ANALYSIS


3.1 Survey Data

The profile data analyzed in this study for Palm Beach and Broward Counties included
four surveys for Palm Beach County and nine surveys for Broward County as
summarized in Table 3.

Table 3

Survey Data Used in This Study

Palm Beach County Broward County
File Name Survey Date(s) File Name Survey Date(s)
PAL74AA.CCC Jan. 1975 BRO76AA.CON Dec. 1976
PAL90AA.CCC July to Oct. 1990 BRO93AA.FMN Oct. 1993
PALOOA.FCM July to Oct. 2000 2425-396.DEP Feb. & Mar. 1996
PAL01A.FCM June & July 2001 BRO97AA.FMN Aug. 1997
2592-998.DEP Aug. 1998
2657-999.DEP Aug. 1999
0901REV.DNR' Aug., Sept. 1991
1101REV.DNR* Dec. 2001, Jan. 2002
BR002.NEW' Feb., Mar., & Aug. 2002
These files have been modified to remove obvious errors.

The data included in the analysis extended from Monument R-189 in Palm Beach County
to Monument R-55 in Broward County, a distance of approximately 93,810 feet, about 18
miles. As shown in Figure 4, the north and south jetties of Boca Raton Inlet are located
36,179 feet and 36,494 feet south of Palm Beach County Monument R-189, respectively.
The corresponding distances for the north and south jetties of Hillsboro Inlet are 64,518
feet and 65,237 feet south, respectively from Palm Beach Monument R-189.

3.2 Nourishments Conducted

The nourishments that were conducted within and adjacent to the area are summarized in
Table 4. The first five entries in the table for Palm Beach County are for the Delray
Beach nourishment project which is actually outside the limits of the area analyzed.
However, as will be discussed later, this area is sufficiently close that it has affected the
volume changes within Segment 1.









R-189 (0 feet)


-R-222 (35,149 feet)
North Jetty (36,179 feet)
Boca Raton Inlet
South Jetty (36,494 feet)
R-223 (36,654 feet)
--- County Line (41,739 feet)










HUlsboro In R-24 and North Jetty (64,518 feet)


South Jetty (65,237 feet)
R-25 (65,397 feet)









R-55 (93,810 feet)




Figure 4. Schematic of System Considered and Distances of Relevant Features
South of Monument R-189 in Palm Beach County.










Table 4


Nourishments of Influence to Segments and Time Periods Analyzed


Palm Beach County Broward County
Nourishment Alongshore Volume Nourishment Alongshore Volume
Date Ranges (yd3) Date Ranges (yd3)
July 1973 R-175.5 to R-188.5 1,635,000 1972 R-7 to R-12 360,000
May 1978 R-177.2 to R-182.7 701,000 1998 R-6 to R-12 555,000
Oct.1984 R-175.5 to R-188.5 1,300,000 1970 R-32 to R-49 1,076,000
Dec. 1992 R-180 to R-188.5 1,198,000 1983 R-26 to R-53 1,900,000
Apr. 2002 R-180 to R-188.5 1,150,000
Aug 1988 R-205 to R-212 1,100,000__ _
Apr. 1998 R-205 to R-212 680,000


3.3 Sand Bypassing at Boca Raton and Hillsboro Inlets

Sand bypassing operations are carried out at both Boca Raton Inlet and Hillsboro Inlet by
relatively small dedicated dredges. The bypassing quantities are based on calibrations of
the dredges and the time histories of these quantities were provided for purposes of this
study. Figure 5 presents the annual and cumulative bypassing quantities for Boca Raton
Inlet and Figure 6 presents the same type of information for Hillsboro Inlet. In addition to
the more or less ongoing bypassing at Boca Raton Inlet, on three occasions a larger
dredge has been utilized to dredge the ebb tidal shoal. Because this report reserves the
term "nourishment" for sediment transported and placed on the beaches from outside the
normally active littoral system, the removal of sand from the ebb tidal shoal and
placement on the downdrift beaches is included here in the bypassing category. These
ebb shoal bypassing events at Boca Raton Inlet are shown as the dotted lines in Figure 5a
and are reflected in Figure 5b as the steeper portions of the cumulative curve.











An


0*



.................. .................;.....................


0 ...~~... .... ..... ..............










197 1952
~~~~~ ~ 5- ( -: --












1981985 1995 20C


Year


a) Annual Bypassing Quantities


1985 1995


Year


b) Cumulative Bypassing Quantities


Figure 5. Historical Bypassing Characteristics at Boca Raton Inlet





10


05
'5


CS,


0
cc
'5)


0
M 2000
0

b
0)

cc
Ca
t0
1000


*6f
(E

E
3



























































































Year


a) Annual Bypassing Quantities


1975 1985 1995




Year






b) Cumulative Bypassing Quantities


Figure 6. Historical Bypassing Characteristics at Hillsboro Inlet.


















11


"Au


140 1


4VU


.....................................





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4.0 CORRECTIONS/MODIFICATIONS TO SURVEY DATA

4.1 Attempts to Correct Survey Data for Non-Closure

The profile surveys analyzed here that extended a sufficient distance seaward to calculate
volumes were always surveyed in two segments: (1) A so-called "wading survey" in
which the person carrying the survey rod walks/wades along the profile and the elevation
is determined, usually with a level, and (2) A "boat" portion of the survey in which the
elevation of the sea floor relative to the water level is determined by a fathometer. Figure
7 shows these two operations schematically. The wading portion of the survey is much
more accurate than the boat portion and is usually conducted at low tide. The reduced
accuracy with the boat survey, which is usually more of a concern with the earlier
(1970's) surveys, is that the water level from which the fathometer soundings were
measured is known only approximately. A common approach to determining an estimate
of the water level reference is by placing a tide gage on a support and the tide gage
recording then serves to establish the vertical datum. In some cases, the tide gage was
placed inside an interior water body or on a bridge pier; however, the water levels at
neither of these locations is representative of the water level on the outer coast where the
surveys are being conducted. An indication that the survey data are in need of correction
is if the outer portions of the surveys do not "close", that is, they are at different
elevations for the various surveys. A further indication of a datum problem is if the outer
portions of the various surveys are more or less parallel. One can argue that if the profiles
do not "close" at their outer extremities, either a correction is in order or the profiles did
not extend a sufficient distance seaward to capture the entire volume change.

Land Survey

Offshore Survey

Bench
Mark






Figure 7. Survey Procedure With Wading Profiles Conducted at Low Tide and Boat
Profiles Conducted at High Tide.

A method that was attempted to correct the outer portions of the profiles in this study is
as follows. A depth of 20 feet was adopted as the depth seaward of which, there should
be little or no actual profile elevation changes. Because the most recent profile was
presumably surveyed with the most modern methods, this profile was adopted as the
reference. Commencing at the distance associated with the 20 foot water depth on the
most recent profile, the differences between the most recent profile and each of the other








profiles was integrated (actually summed) in the offshore direction. Ideally, this integral
(sum) would be zero at all locations seaward of the starting location signifying that there
was no offset in the two profiles under consideration. If this integral (sum) varies linearly
from the starting location, this is an indication of a uniform offset. A least squares
straight line was fit to this integral passing through the starting point (distance
corresponding to 20 foot depth on the reference profile) with the slope of the line
representing the vertical offset which could then be used to correct the profile seaward of
the 5 foot water depth (which was assumed to be the seaward limit of the wading
surveys). All profiles (except the most recent) would be corrected in this manner.

Figure 8 presents four surveys in Broward County at Monument R-15, a profile that
showed a large intersurvey difference in the earliest profile. Is seen that the 1976 profile
is generally at a considerably higher elevation than the other three surveys. Figure 9
presents the variation of the integral (sum) of the deviations from the starting location. It
is seen that the differences between the 1976 survey and the reference profile (2002) are
nearly linear. Also shown in this figure are the vertical corrections indicated by this
method for all three surveys. At this monument, all indicated corrections except for the
1976 survey were small, ie 1976,- 2.57 ft, 1993, +0.13 ft, 1997 : +0.11 ft. Figure 10
presents the corrected profiles where it is seen that all the outer portions of the profiles
are now much more consistent. Also, the elevation reduction in the 1976 profile at the 5
feet water depth is evident.

Thorough inspection of the profiles during the latter portions of this study effort did not
inspire confidence in the described method of correcting profiles and, although earlier
versions of this report included results from this correction method, it was decided to not
include results from this method, but rather to include only the volumes based on
uncorrected profiles. The correction procedure described above is simply not consistent
with the range of characteristics of obvious survey errors. Appendix C presents plots of
all of the monuments from which long survey lines were conducted during the earliest
(1970's) surveys and illustrates some of the potential pitfalls in applying the correction
method. It appeared that to apply this correction method appropriately, each profile
would require treatment individually without a consistent set of rules, thus injecting too
much subjectivity into the analysis. Proceeding with the uncorrected surveys is at least
unbiased and not subjective. In summary, all volumetric results presented in this report
are based on the uncorrected profiles.

4.2 Correction for Monument Relocation

Where appropriate, the survey data were corrected for monument relocation. The
locations of the monuments are presented in State Plane Coordinates in each survey data
set. If the monument had been relocated, the measurements from the new monument
were shifted an appropriate horizontal distance corresponding to the projection of the
shift on the alignment (azimuth) of the profile line.















-..,... .... ................. .............. ......... .... ......... .... ..... ......
S- 1976
: . . .... 1993
i ......... ... ......... .. ............... ............ ............ . ............ . -. .. I_ 7 ......
1997
\ '** *------- 2002
















> -. . . :


Distance (ft)


Figure 8. Four Profile Surveys at Monument R- 15 in Broward County


0

0)
LU







C
2'
a

'U


E


600
1976, m 2.57
1993 m= -0 13
400 - --- 1997,m=-0.11

... .. .. .. .. .. m .. . ... .. . ...... .... ... . .... ... ... ... .. . ...
200




800 -









0 -- -.. ...... . .
200 .
.. . . . . . . .. . . .. . ... . . . . . . . . .. . .


0 100 200 300 400 500 600 700

Distance From 20 foot Contour (ft)



Figure 9. Cumulative Differences in Elevation Beyond 20 foot Depth Distance.
Monument R-15.


2000


3000












... - ....... ......----.. ...-........--...--.............
1976
S: .... 1993
1 I0 ... ... 1997 ....
. . *. :: ........ ...- 2002

S. .. ... .... ..... .......... ... ...... ....... I .. ... .... ... .. .... ........ .. . .... ....





S0

0 1000 2000 3000 4000





0 1000 2000 3000 4000
Distance (ft)

Figure 10. Corrected Profiles at Monument R-15 in Broward County.

5.0 UNCERTAINTIES IN DEVELOPING THE SEDIMENT BUDGETS

5.1 General

It is useful in developing the sediment budgets to understand, to the degree possible, the
uncertainties in the components forming the basis for the sediment budgets. These
components include: volume changes, bypassing quantities by dredge, natural bypassing
around the two inlets, and nourishment quantities. The estimated accuracies associated
with each of these components are discussed below.

5.2 Volume Changes

The volume changes were calculated from the surveyed profiles. The numbers of profiles
in the three segments were: Segment 1, 34 profiles; Segment 2, 29 profiles and Segment
3, 31 profiles. The first surveys (1974/1975 in Palm Beach County and 1976 in Broward
County) extended beyond wading depth at only every third monument, so for the early
surveys, volumes could be computed from only approximately one-third of the profiles.
If errors in the individual profiles were randomly distributed, one would expect that with
the numbers of profiles in a particular segment, the overall volumetric errors would be
relatively small. However, if a bias in the survey data for one time period existed, this
could contribute to a rather large overall volumetric error. As discussed previously, the








most likely cause of a survey bias would be the offsets due to an incorrect vertical datum.
It is difficult to estimate the overall error in calculated volumes; however, the analysis
results for the system of interest will assist later in this effort. The Reader is referred to
the profile plots in Appendix C to develop a partial appreciation of the errors in the early
surveys where a bias appears evident, especially in Segments 2 and 3 of the system under
consideration.

5.3 Bypassing Quantities by Dredge

The reported bypassing rates are based on calibration of the dredge and development of
average pumping rates based on intake pressures and other measurements. Although best
efforts have led to these calibrations and the applications thereof, it is estimated that the
overall bypassing quantities are accurate to within 30%.

5.4 Natural Bypassing Quantities

A natural inlet will establish an ebb tidal shoal which serves as a "sand bridge" for a
portion of the net longshore sediment transport around the inlet. The weir sections present
in the north jetties of the two inlets tend to reduce the quantities of sediment jetted to the
ebb tidal shoal and thus the tendency for natural bypassing. However, the weir and
deposition basin features for the two inlets differ in the degree to which they sequester
sediment. Boca Raton Inlet can only store limited sediment volumes in the inlet channel
whereas Hillsboro Inlet has a substantial deposition basin which has a greater tendency to
prevent sand from being transported to the ebb tidal shoal. Thus, some of the sand that
flows through the weir section in the north jetty of Boca Raton Inlet is accessed by the
dredge and transported to the downdrift beaches and some is jetted to the ebb tidal shoal
which can be fairly prominent. The centroid of the Boca Raton Inlet ebb tidal shoal is
positioned to the south of the entrance channel, in part due to dredging and, possibly in
part, due to the predominant direction of the longshore transport and longshore currents
during ebb tidal flows. As the ebb tidal shoal grows, there is a greater tendency for
natural transport to the south beaches. While it is likely that some sand has been bypassed
naturally, it is not possible to make a quantitative estimate of the associated volumes. As
in the case of volumetric errors, the analysis results presented later may contribute to a
better understanding of natural bypassing quantities.

5.5 Nourishment Volumes

It is estimated that the errors in nourishment volumes are within approximately 20% of
the reported volumes with the actual amount more likely to be greater than reported.









6.0 GRAPHICAL PRESENTATION OF RESULTS


Three graphical formats are used herein to present different types of results as described
below.

6.1 Total Changes in Cumulative Volumes and Planform Areas Within Segments

6.1.1 Changes in Cumulative Volumes

The three shoreline segments considered have been discussed earlier and presented in
Figures 2 and 4. This first graphical format utilizes the four surveys in Palm Beach
County and the nine surveys in Broward County combined with the nourishment
information (Table 4) to determine the total volume and planform area changes in the
three segments. Examples of these results are presented for the total volume changes and
the changes accounting for the effects of beach nourishment.

The procedure described above is straightforward for Segments 1 and 3; however,
because portions of Segment 2 are in the two different counties and were surveyed at
different times, an approximation was necessary. Because approximately 81% of
Segment 2 lies in Broward County, the Segment 2 volume and plan area changes in Palm
Beach County corresponding to the Broward County survey dates were interpolated
linearly from analyzed results from the four surveys in Palm Beach County and then
added to the Broward County results.

Examples of this type of results are presented in Figures 11 and 12 for the volume
changes in Segment 2. The solid line in Figure 11 represents the total volume change
from 1976 and the dashed line is the cumulate nourishment volume in Segment 2 (only
the 1998 nourishment for Segment 2). Figure 12 presents the volume change with the
nourishment deducted. If all of the volume calculations and estimates of nourishment
were exact, this latter quantity would be zero if the bypassing at Boca Raton Inlet and
Hillsboro Inlet were equal. Later presentations of the sediment budget will include this
type of information with the bypassing taken into consideration. Figure 12 indicates that
during the period encompassed by this study, there has been a net increase in volume in
Segment 2 of approximately 740,000 yd3. Additionally, the effects of the 1998
nourishment are evident.





































1980


1990

Year


2000


Figure 11. Total Volume Change With Time in Segment 2
and Cumulative Nourishment in Segment 2.


1980


1990

Year


2000


Figure 12. Volume Change in Segment 2 Minus Nourishment.








18


Total Volume Change
--- Nourishment Volume ..


F-.


2.0

1.8

* 1.6
A
C
0 1.4

S1.2

S1.0
E
S0.8

C 0.6

C 0.4

S0.2
Lo


F


0.0'
1970


C 0.9

S0.8

0 0.7

S0.6

0.5

0.4

C 0.3

(D
C) 0.2
C
=C 0.1
0
0J~


u.1
1970


2010


...........


I I I I i


.......... i


. . . .





.. ... .....


. . . .


..... .... .








.... ....


_.., ................... ..........


..... i






I2

2010


................
..............





----------------



. . . . . . ....
...............


.......... ............. - --i -- ;---


. . .. . . ... . : . .. . . . . . . . . . . .. . . . . .. . . . . . . . . .

.... ............. ---- -:-- -
.. . . . .. .. . .. .. - -- - -- -. . . . .. . . .. .. . . . . . . .. . . . . .. . ..





.............. .................. .....- -i.... . .. . .. .. . . . .



. ... .. ..... .. ... ------ .... .. .. .. .......... .... .. ... .. ...... .....-
. .. . . . . .. . .. . .. . .. . .. . .. . .. . . . .. .. ...









6.1.2 Changes in Total Cumulative Beach Area Within Segments


The total cumulative beach area (area above the NGVD contour) within the three
segments was calculated in a manner similar to that for volumes as just described.
However, there is no basis for correcting total plan areas for nourishment. Figure 13
presents the total cumulative beach area changes for Segment 2 where it is seen that the
shoreline area increased from 1976 to 1993, then decreased until the 1998 beach
nourishment project followed by a general decrease. The results in Figures 11 and 13 for
the total volume and planform area bear general similarities and both have increased over
the period of record examined herein.

S1.5 _
-*- Total Volume Change
------- Nourishment Volume








0.5





1970 1980 1990 2000 2010
Year


Figure 13. Total Plan Area Change in Segment 2.



6.2 Longshore Distributions of Volume and Shoreline Change

Three surveys were used in each county to establish the longshore distributions of
shoreline and volume change and the cumulative distributions of these changes. Figure
14 will serve as a basis for introducing this format. The upper panel in Figure 14
represents the longshore distributions of volume change for the general period: early
1990's to early 2000's. It is seen in Segment 1 that there are volume increases at most of
the monuments with some exceptions near the north side of Boca Raton Inlet. This
general volumetric increase is due, in part, to the nourishment of 680,000 yd3 carried out
in 1998 between R-205 and R-212 (Table 4). Additionally, the Delray Beach
*- 0.0 ---- "---------------------












14 will serve as a basis for introducing this format. The upper panel in Figure 14
represents the longshore distributions of volume change for the general period: early
1990's to early 2000's. It is seen in Segment 1 that there are volume increases at most of
the monuments with some exceptions near the north side of Boca Raton Inlet. This
general volumetric increase is due, in part, to the nourishment of 680,000 yd3 carried out
in 1998 between R-205 and R-212 (Table 4). Additionally, the Delray Beach













2(

C







4)-0
E4-




C)-c

E


.............. ...




.. .. .. ..


0 10000 20000 30000 40000 50000 60000 70000 80000 90000 100000
Longshore Distance (ft)

a) Longshore Distribution of Volume Change Rates,
Early 1990's to Early 2000s.


i-
150000

0 130000

0 110000
co
90000
0)
r 70000
10
50000
0
E 30000
0 10000

0 -10000

S -30000

E -50000
3
0


H i : i : : :I 9 o ! ., ; I

S .. .. ..... .. .. --- ...... ... .. .... . .. ... .....









....1. .4 ... ... .` .. ;......... ....... ... ........ . . . .. .........





D 10000 20000 30000 40000 50000 60000 70000 80000 90000 100000
Longshore Distance (ft)


b) Cumulative Distribution of Volume Change Rates, Early 1990's to Early 2000's


Figure 14. Distributions of Volume Change Rates and
Cumulative Change Rates For Period: Early 1990's to Early 2000's.
Calculations to 20 feet Depth Distance Offshore.


0



0



0


8
9
a
xl


a








nourishment project which commenced in 1973 and in which 4,834,000 yd3 had been
placed by 2001 has influenced the northern portion of this segment. In Segment 2, the
volume changes are also dominantly increases, and again due in part to the 1998
nourishment of 555,000 yd3 between monuments R-6 and R-12 in Broward County. In
Segment 3, the changes are both accretion and erosion and there have been no large scale
beach nourishment projects in this time period represented by the two surveys.

The lower panel in Figure 14 presents the cumulative volume changes within the three
segments. In Segment 1, the volumes are accumulated starting at the north jetty of Boca
Raton Inlet toward the north. In Segment 2, two cumulative curves are presented with one
curve commencing at the south jetty of Boca Raton Inlet and continuing south to the
north jetty of Hillsboro Inlet and the second curve commencing at the north jetty of
Hillsboro Inlet and continuing north to the south jetty of Boca Raton Inlet. Of course,
these two curves in Segment 2 are related as they are both based on the same volume
change information (upper panel). In Segment 3, the volume changes are accumulated
commencing at the south jetty of Hillsboro Inlet and continuing south to Monument R-
55. In Segment 1, the total volumetric accumulation rate from the north Boca Raton Inlet
jetty north to Monument R-189 is 61,500 yd3/year. This is compared to the average beach
nourishment placement of 61,800 yd3/year. Additionally, it is estimated that a total of
some 40,000 yd3/year has entered the northern portion of Segment 1 as a result of the
Delray Beach nourishment project. Segment 2 has experienced a volume increase of
approximately 100,000 yd3/year whereas the average nourishment rate is 61,700 yd3/year.
Segment 3 lost volume at an average rate of 11,500 yd3/year during this period when no
nourishment occurred in this segment.

The complete set of the graphs of this type will be presented later in the "Results and
Interpretation" section including shoreline changes and cumulative shoreline changes
(changes in plan area). It can be appreciated that the information available in plots of the
types presented forms the basis of a sediment budget, a primary objective of this study.








6.3 Sediment Budgets


The third graphical format employed to present results is the sediment budget. The basis
for the development of the volumetric sediment budgets is presented in Appendix B. An
example of the format used to present the sediment budgets is shown in Figure 15. The
information in this type figure is in average yd3/yr and accounts for all nourishment and
bypassing. As will be discussed in greater detail later, this allows estimates to be
developed of the net longshore sediment transport into the northern boundary of the
system (R-189 in Palm Beach County) and out of the system (R-55 in Broward County).
Additionally, the amount of information available allows a check of the results in
Segment 2 where the net volume change based on nourishment and bypassing can be
compared with that calculated from surveys providing an overall basis for evaluating
accuracy of calculations, volumetric and nourishment estimates and bar bypassing with
the caveat that bar bypassing may be reasonably large at Boca Raton Inlet. This type
results and their interpretation will be discussed in greater detail later.









Second Period


Q__N = 149,500 yd3/y

dV/dt = 169,900 yd3/yr



QNOUR 73,300 yd3/yr



Boca Raton Inlet> Boca Raton Ii
---?- = 53,000 yd3/yr
(1975 -1990)
= 47,000 yd3/yr
(1976 to 1993)


IV/dt = 13,300 yd3/yr
vs 26,500 yd3/yr (Calc)

QNOUR = 0


Hillsboro Inlet Hillsboro In
Bp = 73,500 yd3/yr


S dV/dt 66,800 yd3/yr


QNOUR = 111,760 yd3/yr

Qour = 118,460 ydy


QI = 85,100 yd3/yr

dV/dt = 61,500 yd-/yr



QNOUR = 61,800 yd3/yr



nlet BP = 86,400 yd3/yr
1990 to 2001)
) = 88,900 yd'/yr
(1993 to 2002)

dV/dt 100,200 yd3/yr
vs 22,600 yd3/yr (Calc)


QNOUR = 61,700 yd3/yr




let QBP = 128,000 yd3/yr



dV/dt = -11,500 yd'/yr


QNOUR = 0
Qour = 139,500 yd3/yr


Figure 15. Volumetric Sediment Budgets For Early and Later Time Periods.


First Period










7.0 RESULTS AND INTERPRETATION

Results are presented and interpreted in the three formats presented in earlier sections of
this report.

7.1 Cumulative Plan Area and Volume Changes With Time for the Three Sections

7.1.1 Segment 1

Figures 16 through 18 present the results for cumulative plan area changes and volume
changes for Segment 1. The cumulative plan area in Segment 1 (Figure 16) increases
from 1974 to 1990, then decreases from 1990 to 2000 and increases from 2000 to 2001.
Overall, there has been a total of approximately 1,590,000 square feet of dry beach area
accumulation from 1975 to 2001. During the period represented in Figure 16, there has
been a total of 1,780,000 yd3 of nourishment within Segment 1 and 4,834,000 yd3 of
nourishment immediately north of Segment 1 (the Delray Beach Nourishment project).
Both of these nourishments undoubtedly contributed to the positive cumulative plan area
changes shown in Figure 16.


2.0
S1.8
. 1.6
S 1.4
) 1.2
) 1.0
0.8
o
0.6
.E 0.4
0 0.2
C 0.0
1970


1980 1990 2000
Year


Figure 16. Cumulative Plan Area Changes in Segment 1.











































1990


2000


-*- Total Volume Change
---L--- Nourishment Volume










. . . . . . . . . . . . . .


Year

Figure 17. Cumulative Volume Changes in Segment 1
and Nourishment History.


1980 1990 2000

Year


Figure 18. Cumulative Volume Changes Minus Nourishment in Segment 1.


2010


An


1970


... ~.. .... .. .



i :l


S1.8

O 1.6
(A

0 1.4

1.2

1.0 -


O 0.8

. 0.6

a)
) 0.4

* 0.2

0.0
1970


2010


.............


-------------


.............


. . . .

.. . . .. . . . . . . .
.........


/











Figure 17 presents the volume changes. The nourishment volume additions in Segment 1
are also presented in this figure. Figure 18 presents the volumes with the nourishments in
Segment 1 subtracted. It is seen that the volume gain without nourishment is
approximately 1.4 million yd3. It has been estimated previously (Dean, 2002) that at least
0.8 million yd3of this increase is due to transport induced by the Delray Beach
nourishment project located immediately to the north of Segment 1. This conclusion is
reinforced by the study by Beachler (1993) which found that by 1990, the nourishment
spreading effects of the Delray Beach nourishment project extended at least two miles
south of the Project limits and, based on his Figure 4, considering the 1974 to 1990
surveys, there was an average of 25,800 yd3/year deposited within the first two miles
south of the Project.

7.1.2 Segment 2

Figures 19 through 21 present cumulative plan area and volume change information for
Segment 2. As for Segment 1, the plan area changes also increase with some oscillations.
These oscillations may be due, in part, to the greater number of surveys providing greater
detail in Broward County. It is seen from Figure 19 that over the total period represented,
there has been an increase of approximately 750,000 square feet during which there has
been nourishment of 555,000 yd3 within Segment 2.











C 1.5
'5
0)

















0.0,
1970
I 1.0 -



a)


0 0.5 -







) 1970


1980


1990

Year


2000


Figure 20. Cumulative Volume Changes in Segment 2
and Nourishment History.









27


1980 1990 2000 2010
Year



Figure 19. Cumulative Plan Area Changes in Segment 2.


2.0

0 1.8

0 1.6










0
0 1.4

S1.2




0.8

e 0.6

0) 0.4

- 0.2
C.


F


fin L


u.u
1970


2010


0-t- Total Volume Change
----Nourishment Volume .............''''~~ ''''' ~`~~ '

....... ....... .... I ...... ...... I ....... ....... ........ .... ''''






...................... ....... ..... .............r-- -- - -
.. . . ------ ---- -------- -- -

............. ........ ..... ........: ... ;- :
........... ............ ..... ----------..... ... ..........




- - - - - - - . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . ... . . . .
.............. ... ......... ... ........;rr ......... .............. ... ..... . ... .










1.0

S0.9

0 0.8
(0
C)
o 0.7

0.6

S0.5

S0.4

C 0.3
0)
I0 0.2

S0.1

0.0
1970


1980


1990


2000


2010


Year

Figure 21. Cumulative Volume Changes Minus Nourishment in Segment 2.


The volume changes and the nourishment in Segment 2 are presented in Figure 20. It is
seen that there is a gradual increase to 1997, followed by an abrupt increase from 1997 to
1999, due to the 1998 nourishment of 555,000 yd3, followed by general stability. Figure
21 presents the volumes minus the 1998 nourishment. It is seen that there is a general
stability in volumes following the 1998 nourishment. This is compared to the
(anticipated) decrease in plan area subsequent to the 1998 nourishment (Figure 19).


7.1.3 Segment 3


The cumulative shoreline area and volume changes in Segment 3 are shown in Figures 22
through 24. As for the other two segments, these results show an overall increase in
cumulative shoreline area. Referring to Figure 22, the total area increase over the period
represented is approximately, 2,100,000 square feet. During the period represented, there
has been nourishment of 1,900,000 yd3 within Segment 3.

















28


.. . .. .. .. .. .. . . .. .. .. .. .. - - - - -









. . . . . . . . . . . . : - - - - -


i -- - ----.- ---- - -........... ...........-


. . . . . . . . . . ~ '
. . . . . . . . . . .'' '
. . . . . . . . . . . . .'
. . . . . . . . . . . . .~
. . . . . . . . . . .


/ "6










3


O









U)
I-


Co


o 1970 1980 1990 2000 2010
Year

Figure 22. Cumulative Plan Area Changes in Segment 3.






3

S---A-- Nourishment Volume .....

.. . .. . .. . .. . . .
0












U'i

-1
. . . . . .--- - . . . . . . . . . . .









O



1970 1980 1990 2000 2010
Year

Figure 23. Cumulative Volume Change in Segment 3.




















-3
0 2 ............. .............. ............ ............... ............. .............. ........... ............






0- -- -------A--- ---
::> ............. ..... .......... ... ............ .................. .. ...... .......




0 z
S - -- .- .---- . .. .. . . . . . . .. . .. .. . .. . . . . . .. . .. . . . . . . . .


-3 1-----------........... .......-------- --------
Q
-3
1970 1980 1990 2000 2010
Year

Figure 24. Cumulative Volume Change Minus Nourishment in Segment 3.

The volume changes in Segment 3 and the nourishment volume placed directly within
Segment 3 during the period represented are shown in Figure 23. It is seen that from 1976
to 1993, the volume increase is certainly related to, but less than, the nourishment. This
may be due, in part, to a 1970 nourishment placed within Segment 3 (R-32 to R-49) of
1,076,000 yd3 which was still inducing sediment transport from the Segment 3 system
during the period examined here. Figure 24 presents the total volume changes minus the
nourishment volumes placed in Segment 3.

























30








7.2 Distributions and Cumulative Distributions of Shoreline and Volume Changes in
Various Segments

7.2.1 General

This second presentation format has been explained earlier in this report and is one in
which the distributions of shoreline and volume change rates are presented on a
monument by monument basis and also the cumulative shoreline and volume change
rates are presented in each of the three segments. These presentation formats provide a
convenient basis for examining the rates of change at any location in the shoreline
segment of interest.

These types of results are presented for two periods as discussed earlier. For Palm Beach
County, the early period is from 1974/1975 to 1990 and the second period extends from
1990 to 2001. For Broward County, the time periods are from 1976 to 1993 and 1993 to
2002. As is evident, these periods are not the same for the two counties which
complicates Segment 2 since it lies in both counties but predominantly (89%) in Broward
County. These two periods will be referred to as the "Mid 1970's to Early 1990's" and
"Early 1990's to Early 2000's", respectively. They will also be termed the "Early" and
"Later" time periods for convenience. Finally, these results are presented as annual rates
which facilitates the interpretation in sediment budget terms.

7.2.2 Early Time Period: Mid 1970's to Early 1990's

7.2.2.1 Shoreline Changes, Early Time Period

Figure 25a presents the longshore distribution of shoreline change rates on a monument
by monument basis for this early time period. Several features are evident from this
figure. First, it appears that there has been a net shoreline accumulation against the north
Boca Raton jetty (recall that the weir section in the north jetty was opened in 1980). Also,
the 1988 North Boca Raton Beach nourishment project of 1,100,000 yd3 is evident.
Relative to the longshore distance in Figure 25, this nourishment occurred from 16,700
feet to 24,700 feet south of Monument 189. The effect of the Delray Beach nourishment
project is evident near the north end of Segment 1 and appears to extend southward to at
least 9,000 feet.

In Segment 2, one monument shows large shoreline recession immediately south of Boca
Raton Inlet and the effects of the 1985 ebb tidal shoal bypassing is evident (221,000 yd3
between Monuments R-223 and R-225.6). Finally, it appears that the shoreline has
generally built out north of Hillsboro Inlet. In Segment 3, the 1983 nourishment project
of 1,900,000 yd3 which extended from Monument R-26 to R-53 is evident.

Figure 25b presents the cumulative shoreline changes derived from the results in Figure
25a. These results are a different way of considering the results in Figure 25a and allow











20 b


10 .. . . ... . . . .
N'i ... 11 ji.

a1 1 1
Q5
r.1
4)


t-
C
C-)
a

o
I
u,


I | . | | i | i | 2 | .| i : .
I N I I i I- i N i I I H i I I i

: : : i :
..... ..... ..... ..... ... .. ..... ..... .......

.20
0 10000 20000 30000 40000 50000 60000 70000 80000 90000 100000
Longshore Distance (ft)

a) Longshore Distribution of Shoreline Change Rates,
Mid 1970's to Early 1990s.




0000 .. . . .. ..

1240000 .






20000 .................
.............. .......... ........ .- .........



60000 .... ......... .......... .... .....
.oooo i.....



0 .o i i I

0 ----"-----I--- I ; ^ f --I f --I [ :-- ----- ----
-o uw --- -i -- - - -i -- --- 1 -- -- --


0 10000 20000 30000 40000 50000 60000 70000 80000 90000 100000
Longshore Distance (ft)


b) Cumulative Distribution of Shoreline Change Rates, Mid 1970's to Early 1990's.


Figure 25. Distributions of Shoreline Change Rates and Cumulative Change Rates for
Period: Mid 1970's to Early 1990's.










32


[
I.
\

i
i
I


-20000








quantification of the total cumulative shoreline change rate at any shoreline location. At
monuments where there is a large shoreline change rate, the cumulative curves in Figure
25b have steep slopes. It is seen that at the north end of Segment 1, the average annual
planform area had increased by approximately 118,000 ft2 per year over this 15 year
period. In Segment 2, the value is approximately 37,000 ft per year. In Segment 3, the
average is approximately 121,000 ft2 per year.

7.2.2.2 Volumes Changes, Early Time Period

The monument by monument volume changes and cumulative volume changes for this
early period are presented in Figures 26a and 26b, respectively. For this period, the
volumes increased in all three segments. Segment 1 volumes increased by approximately
170,000 yd3/year, in Segment 2, the increase was 13,300 yd3/year and in Segment 3, the
increase was approximately 67,000 yd3/year.











20


10 '-- :-- -- --:-.-:- .-: ----- : --!.-- --. --: --- -:
m15


10 ... ...











a) Longshore Distribution of Volume Change Rates,
0 10000 Mid 1970's to Early 19 700 8 9's 1
Longshore Distance (ft)

a) Longshore Distribution of Volume Change Rates,
Mid 1970's to Early 1900's.


200000


150000


100000


Rn000


E -50000
0 10000 20000 30000 40000 50000 60000 70000 80000 90000 100000
Longshore Distance (ft)

b) Cumulative Distribution of Volume Change Rates, Mid 1970's to Early 1990's.

Figure 26. Distributions of Volume Changes and Cumulative Change Rates for Period:
Mid 1970's to Early 1990's. Calculations to 20 feet Depth Distance Offshore.






34


B I







. . . . : .. .....









7.2.3 Later Time Period


7.2.3.1 Shoreline Changes, Later Time Period

The monument-by-monument shoreline change results are presented in Figure 27a and
the cumulative results are presented in Figure 28b. In Segment 1, it is seen that there is a
general shoreline recession for several thousands of feet north of Boca Raton Inlet, and
generally mixed changes to the north within the limits of Segment 1. It may seem
surprising that there is not a greater signal from the 1998 nourishment of 680,000 yd3 in
the same location as the earlier (1988) North Boca Project; however, this may be due to
the larger 1988 project (1,100,000 yd3) profiles continuing to equilibrate (shoreline
recession) which had a greater effect than the shoreline advancement from the 1998
project. Overall, referring to the cumulative curves, Segment 1 lost area and Segments 2
and 3 both gained area at about the same rate. Most of the Segment 2 gain was in its
northerly portion where the 1998 nourishment of 555,000 yd3 occurred.

7.2.3.2 Volume Changes, Later Time Period

The corrected monument-by-monument and cumulative results are presented in Figures
28a and 28b, respectively. As expected, it is seen that the volume changes are more
consistent with the nourishment carried out than the shoreline changes. Whereas the
overall net shoreline area change in Segment 1 was negative, the cumulative volume
change for Segment 1 is positive. As noted, this is consistent with profile equilibration
that occurs after beach nourishment, particularly the relatively large 1988 North Boca
Raton nourishment project. Of interest are the substantial differences between the early
and later time periods as will be discussed in greater detail later. The net annual rates of
volumetric change in Segments 1, 2 and 3 are + 61,500 yd3/year, + 100,200 yd3/year, and
- 11,500 yd3/year, respectively.


















(U
2







0
0


.2
0n
c
I-
0



u,


!0


0 10000 20000 30000 40000 50000 60000 70000 80000 90000 100000

Longshore Distance (ft)



a) Longshore Distribution of Shoreline Change Rates,
Early 1990's to Early 2000's.


50000

40000

30000

20000

10000

0

-10000

-20000

-30000

40000


-50000 .. .
0 10000 20000 30000 40000 50000 60000 70000 80000 90000 100000

Longshore Distance (ft)


b) Cumulative Distribution of Shoreline Change Rates, Early 1990's to Early 2000's.


Figure 27. Distributions of Shoreline Change Rates and Cumulative Change Rates for
Period: Early 1990's to Early 2000's.


0 : : ; : : :: : : ;. : I:
....... .... : ----! - i -,---- .. .. .. .. .. ... .. .. .. .. . .


o '- i j- ................ ..... i, -:


0 Tr




0....



.. . . .. .. .. ..0. .. . . .. .. .


.....i....i....j~~..i....i................ ........ ......---;; 1

::::::~::::::::j::: :::: j....i.................. 4



.. i : l . . j. i l il i ........ . ... . . .. ... .. .. .



_.......i.. .....i....i.... .................

...i...... .....i..... .... ...... ...




... ........:... .. .. ...... ..... ... ..


;'i''';''''''''''''












.i.i : . . . .:. : :.I .


10 .............................. ...... ........... ... .. ............. ............ .....
c 1 i l I Ii I




I, i i |-' 'T 'Ti j''i : i **i7 !"****i




0 10000 20000 30000 40000 50000 60000 70000 80000 90000 100000
Longshore Distance (ft)



a) Longshore Distribution of Volume Change Rates,
Early 1990's to Early 2000's.


4) -1 0 ...... ....... . .........
1500000
.... .... .... ... .... . .................... .. .... .. ... ......
S: : *o : :, : : : .. :-** --
S 13000.. .............. ..." "...."... ... ....... .. .." "..".............. ......':... :- -



0,


0000 ...... ..... ..
rE -0000 .....---j ...-. ... ... --


S -10000..... .......... ........."...... .. .. ....... .

E -50000 .
S 0 10000 20000 30000 40000 50000 60000 70000 80000 90000 100000
Longshore Distance (ft)

b) Cumulative Distribution of Volume Change Rates, Early 1990's to Early 2000's.

Figure 28. Distributions of Volume Change Rates and Cumulative Change Rates for
Period: Early 1990's to Early 2000's. Calculations to 20 feet Depth Distance Offshore.






37








7.3 Sediment Budgets


7.3.1 General

The basis for the development of the volumetric sediment budgets is presented in
Appendix B. Of primary significance are the natural cycles that exist in wave and
sediment transport characteristics, including the net longshore sediment transport which
forms the primary basis for appropriate sediment bypassing characteristics. Thus, because
the volumes of sediment transported along the shore can vary substantially from one year
to the next, it is not appropriate to plan to bypass the same quantities of sediment on an
annual basis. A more realistic approach is to plan on an average bypassing quantity and to
adjust the annual bypassing quantities according to relative volume changes north and
south of the inlet. Methods of quantifying these adjustments will be addressed in later
sections of this report. Sediment budgets were developed for the two time periods
represented by Figures 25 through 28 in the preceding section of this report. These
sediment budgets account for the bypassing and nourishment.

The sediment budgets for the volume changes are presented in Figure 29 and are
discussed in the following paragraphs.

7.3.2 Sediment Budgets For Each of Three Segments

Figure 29, shown earlier as Figure 15, presents the volumetric sediment budget for the
Early and Later time periods. It is seen that the calculated sediment transports into
Segment 1 differ substantially for the two time periods whereas the sediment flows out of
Segment 3 are in better agreement. Although the distance encompassed was
approximately 18 miles, one would not expect the net natural longshore sediment
transport quantities to change greatly over this distance. It is somewhat surprising that the
Early time period values of transport into Segment 1 and transport out of Segment 3
appear more consistent with expectations than the Later time period even thought the
survey techniques are expected to be better during the Later time period. Also the volume
changes calculated from surveys and based on nourishment and bypassing quantities are
in better agreement during the Early than Later time period.

It is of interest (and perhaps relevant) that the reported bypassing quantities at Hillsboro
Inlet are significantly greater than those at Boca Raton Inlet for both time periods: Early
time period: approximately 20,000 yd3/year greater and Later time period: approximately
40,000 yd3/year greater. Also, because the Delray Beach nourishment project was in its
earlier stages of evolution during the Early time period, there may have been more
induced sediment flows into Segment 1 during the Early than Later time periods.

Focusing on the Later time period, it is noted that there was a volumetric rate of increase
of 77,600 yd3/year more in Segment 2 as determined by surveys than can be accounted
for by the reported bypassing and nourishment quantities. If, as an example, the sum of
the natural and net hydraulic bypassing at Boca Raton Inlet during the second time period








Second Period


- IN = 149,500 yd3/y

dV/dt = 169,900 yd'/yr



QNOUR 73,300 yd3/yr


SQN = 85,100 yd3/yr

dV/dt = 61,500 yd3/yr



QNOUR = 61,800 yd3/yr


W W
Boca Raton Inlet Boca Raton Inlet BP = 86,400 yd3/yr
BP = 53,000 yd3/yr 1990 to 2001)
(1975 -1990) 88,900 yd3/yr
= 47,000 yd'/yr (1993 to 2002)
(1976 to 1993)


IV/dt = 13,300 yd3/yr
vs 26,500 yd3/yr (Calc

QNOUR = 0


Hillsboro In]
= 73,500 yd3/yr


dV/dt 66,800 yd3/yr


QNOUR = 111,760 yd3/yr

__ Qovr = 118,460 yd'/y


dV/dt 100,200 yd3/yr
vs 22,600 yd3/yr (Calc)


QNOUR = 61,700 yd3/yr




let QBP = 128,000 yd'/yr



dV/dt = -11,500 yd3/yr


QNouR 0


4C |QouT = 139,500 yd3/yr
?"V~~


Figure 29. Volumetric Sediment Budgets For Early and Later Time Periods.


Hillsboro


First Period









was greater than reported by this 77,600 yd3/year, the sediment budget in Segment 2
would be balanced and the sediment inflow to Segment 1 would be 162,700 yd3/year
versus 139,500 yd3/year transported out of Segment 3 as determined by survey and
reported bypassing quantities. This discussion has focused on modifications of bypassing
quantities at Boca Raton Inlet; however, it can be shown that in order to balance the
volumes in Segment 2, it is only necessary that the difference between the sediment
bypassing around Boca Raton Inlet minus that around Hillsboro Inlet be increased by
77,600 yd3/year and this would automatically result in the net sediment transport into
Segment 1 and out of Segment 3 to agreeing within 23,200 yd3/year which is considered
reasonable recognizing that some sediment transport is induced into Segment 1 as a result
of the large Delray Beach nourishment project (Table 4). Therefore it is suggested that
not too much concern be placed on differences less that 40,000 yd3/year transported into
and out of Segments 1 and 3, respectively.

It is noted that for the Early time period, increasing the flows around Boca Raton Inlet
relative to Hillsboro Inlet for the Early time period would tend to balance the volume
differences for Segment 2 (39,800 yd /year would be required); however, this would
further increase the differences between the sediment transport into Segment 1 and out of
Segment 3. Again, the Delray Beach nourishment project plays a definite but
unquantified role here.

Finally, the effect of the offshore reef structures on sediment transport should be noted. It
has been stated earlier that the net sediment transport into Segment 1 should be
approximately equal to the transport out of Segment 3. This is expected to be the case for
natural conditions. However, if nourishment covers portions of the reef structures within
the active sediment transport zone, the transport on these portions of the active profile
will be increased and the transport under the same wave conditions will increase thereby
causing an imbalance between QN and Qour.

7.3.4 Global Sediment Budgets

The above sediment budget calculations have focused on each of the three segments. As
was evident, the bar bypassing was an unknown in the quantification of the budgets for
each of these three segments. As shown in Appendix B, it is possible to consider a
"Global Sediment Budget", ie one that combines all three segments. There are advantages
and disadvantages to consideration of a global sediment budget. The main advantage is
that bypassing at the two inlets does not appear in the budget since it is internal to the
overall system. The main disadvantage is that it is only possible to determine the
difference between the net sediment transport into the north end of the total system
considered and the transport out at the south end of the system. That is, the method can
only quantify the difference AQ where

AQ = Qm -Qoo








Ideally, this transport difference should be small relative to the absolute values of the
various components. It can be shown (Appendix B)


AQ = Q Qor = N (QdV (QNoUR)
1=1 Mt )i j=1

which simply states that the difference in inflow and outflow of sediment is the difference
between the volume stored in the system and the volume placed in the system through
nourishment. The values in Figure 29 were substituted into the above equation and the
results are shown in Table 5. It is seen that the differences are less for the Later
intersurvey period than for the Early period. As noted previously, this could be due to the
larger profile spacing for the long lines for the Early period. Additionally, it is known that
there is a substantial amount of sediment inflow into the system considered as a result of
the Delray Beach nourishment project. Considering that QN and Qour are on the order of
125,000 yd3, the percent transport differences in Table 5 range from 21% to 52%.

Table 5

Results of "Global Sediment Budget" Analysis

Time Period AQ (yd3/year)
Early 64,940
Later 25,700


8.0 RECOMMENDED SEDIMENT BUDGET PROTOCOL FOR BOCA RATON
INLET

8.1 General

Previous discussions and the analysis results have emphasized that there may be
substantial interannual differences in the appropriate sediment budget for Boca Raton
Inlet. These differences are due primarily to the wave climate, particularly the wave
directions and wave heights. Some years are more stormy than others and thus may cause
more net longshore sediment transport. Additionally, in discussing the need for hydraulic
(dredge) bypassing around Boca Raton Inlet, the natural bypassing component should be
recognized.








8.2 Recommended Sediment Budget Protocol for Boca Raton Inlet


In view of the above discussion and the findings of this report, the recommended
elements of a sediment budget protocol for Boca Raton Inlet include the following:

(1) Maintain a capability to bypass 100,000 yd3/year which includes bypassing from
the ebb tidal shoal as needed.
(2) Quantify the hydraulic bypassing need through an analysis of annual surveys
conducted north and south of the inlet. These surveys should extend 5,000 feet
north and 5,000 feet south of the inlet and the effects of beach nourishment should
be taken into consideration in the analysis using accepted coastal engineering
procedures. The surveys should be conducted at approximately the same time
each year and should extend to at least the 30 foot depth contour. This
quantification should be based on a determination of required bypassing changes
in the year following the survey to balance differences in the volume changes
updrift and downdrift of Boca Raton Inlet occurring during the previous year. It is
suggested that these results and their interpretations be shared with representatives
of the updrift and downdrift Stakeholders. The downdrift volumes should not
include those sequestered in the Boca Raton Inlet ebb tidal shoal.

9.0 POSSIBLE FUTURE EFFORTS

9.1 Deerfield Beach Groin Field

The Deerfield Beach groin field was installed subsequent to and partly as a result of the
severe March 1962 storm. This field comprises 53 groins with the first groin at the north
Broward County Line and the southern most groin at the Deerfield Beach/Hillsboro
Beach City boundary. These groins are constructed of King Piles with rubble mounds at
the seaward ends and are spaced at approximately 100 feet. King Pile groins are
adjustable and consist of concrete piling in the planform of the letter "H" with panels
(wooden or concrete) placed in the slots formed in the "H" section, see Figure 30.
Additionally, there are several (four or more) less prominent groins along the northern
portions of Hillsboro Beach. The Deerfield Beach groin field occupies approximately
19% of the Segment 2 shoreline. However, in addition, the Deerfield groin field retains
sand in the compartment to the north extending to the south jetty of Boca Raton Inlet.
Thus, this groin field affects (stabilizes) to some degree approximately 40% of the total
shoreline of Segment 2.












) STABILIZED PROFILE


. ORIGINAL PROFILE-. i

CONCRETE BASE PANEL


SKING-PILE (PRESTRESSEO)

12"WOODEN PANELS


-KING PILE


Figure 30. Typical King Pile Groin Installation.
Note: Rubble Mounds at Ends of Groins Not Shown.

An effort to quantify the effect of the Deerfield Beach groin field would include an in
depth analysis of survey-based shoreline and volume changes focused on the vicinity of
the groin field and affected updrift and downdrift areas. Additionally, numerical
modeling of shoreline and volume changes would be conducted to complement the
survey-based analysis results. Emphasis would be directed to: (1) Volumetric retention
within and north of the groin field, (2) Stabilization of offshore region seaward of the
groins as they have filled, (3) Details of sand bypassing around the groin field (downdrift
attachment locations), and (4) Downdrift effects of groin fields under various seasonal
wave climate scenarios.

9.2 Bar Bypassing Around Boca Raton Inlet

An unquantified issue in this report is the quantity of sand bypassed around Boca Raton
Inlet by natural transport on the ebb tidal shoal ("bar bypassing"). The ebb tidal shoal
serves as a "sand bridge" with the shoal increasing in size until it can bypass the full net
longshore sediment transport. However, the bar geometry (depth over the bar) for
bypassing of the full net longshore sediment transport is not consistent with safe
navigation, thus requiring dredging.

The most appropriate approach to investigating bar bypassing is through a focus on the
available survey data in the immediate vicinity of the Boca Raton Inlet coupled with a
sand tracer experiment and results of a literature review of similar cases. It is considered
that there would be considerable uncertainty associated with results obtained from the
sand tracer experiment. Therefore if a decision is reached to proceed with an
investigation of bar bypassing, it is suggested that the study options and their prognoses
for success be reviewed carefully.









10.0 SUMMARY AND CONCLUSIONS


10.1 Summary

This report has analyzed the shoreline and volume changes in the vicinity of Boca Raton
Inlet. A total longshore distance of approximately 94,000 feet was included in the
analysis extending from Monument R-189 in Palm Beach County, some 36,200 feet north
of Boca Raton Inlet to Monument R-55 in Broward County, approximately 28,600 feet
south of Hillsboro Inlet. The survey data analyzed in Palm Beach County includes four
separate surveys: 1974/1975, 1993, 2000 and 2001 whereas nine surveys were analyzed
in Broward County: 1976, 1993, 1996, 1997, 1998, 1999, 2001 (two surveys in 2001) and
2002.

This system is unique in terms of the amount of data available including the bypassing at
the two inlets, each of which includes a weir in the updrift (north) jetty, and the various
nourishment projects that have been conducted within and adjacent to the area analyzed.
The survey and other data were combined to establish sediment budgets over two time
periods for the system of interest with an emphasis on Boca Raton Inlet. The system was
represented in three natural segments with Segment 1 approximately 36,200 feet long and
located north of Boca Raton Inlet, Segment 2 between Boca Raton and Hillsboro Inlets
and approximately 28,000 feet in length and Segment 3 south of Hillsboro Inlet and
28,600 feet long. Because nourishment in close proximity to the overall system
boundaries (either inside or outside) will induce sediment transport out of or into the
system over and above that which would naturally occur, these effects were taken into
account both quantitatively and qualitatively.

Analysis results were presented in three formats. A complicating factor in all three
formats was that Segment 2 lies in both counties (but predominantly in Broward County)
and the survey dates for the two counties do not coincide. One format was the variation
with time of the volume changes within each segment which included the effects of
nourishment and with the nourishment deducted. This format shows the overall changes
in the system segments and highlights the role of beach nourishment. The second format
was to select three surveys in each segment and to develop distributions of shoreline and
volume changes for the three segments and the two intersurvey periods. The intersurvey
periods investigated for Palm Beach County are: 1975 to 1990 and 1990 to 2001. The
corresponding periods for Broward County are: 1976 to 1993 and 1993 to 2002. These
plots allow easy quantification and identification of the locations of shoreline and volume
changes. The sediment budgets developed for the two time periods establish a natural net
southerly flow of sediments across the northern boundary into Segment 1 ranging from
approximately 85,100 yd3/year to 149,500 yd3/year and flows out of the southern
boundary ranging from 118,460 yd3/year to 139,500 yd3/year. Finally, the third format
presented the results in a sediment budget framework for the same time periods as for the
second format. These results identified discrepancies in the volume changes in Segment 2
as determined from survey data and reported bypassing quantities and differences
between calculated net transport into Segment 1 and out of Segment 3. The calculated








volumes during the Later time period were considered more accurate and it was found
that if the relative bypassing at Boca Raton and Hillsboro Inlets were increased, both the
discrepancies in Segment 2 and the differences in net transport at the two ends of the
system considered could be reduced to reasonable values for the Later time period. A
portion of this increase may be due to the natural bypassing along the Boca Raton Inlet
ebb tidal shoal. Additionally, sand transport has been induced into the north end of
Segment 1 by the Delray Beach nourishment project immediately to the north of this
segment.

Available historical survey data have been analyzed to establish a recommended
sediment budget for Boca Raton Inlet and the overall sediment budget for the
encompassed area has been clarified. A sediment budget protocol for Boca Raton Inlet is
recommended.

10.2 Conclusions

Although some uncertainties remain in the calculated volumetric changes and reported
bypassing, a reasonably solid basis for a recommended sediment budget protocol for
Boca Raton Inlet has been developed as follows:

(1) Maintain a capability to bypass 100,000 yd3/year which includes bypassing from
the ebb tidal shoal as needed.
(2) Quantify the hydraulic bypassing need through an analysis of annual surveys
conducted north and south of the inlet. These surveys should extend 5,000 feet
north and 5,000 feet south of the inlet and the effects of beach nourishment should
be taken into consideration in the analysis using accepted coastal engineering
procedures. The surveys should be conducted at approximately the same time
each year and should extend to at least the 30 foot depth contour. This
quantification should be based on a determination of required bypassing changes
in the year following the survey to balance differences in the volume changes
updrift and downdrift of Boca Raton Inlet occurring during the previous year. It is
suggested that these results and their interpretations be shared with representatives
of the updrift and downdrift Stakeholders. The downdrift volumes should not
include those sequestered in the Boca Raton Inlet ebb tidal shoal.


11.0 ACKNOWLEDGEMENTS

This effort benefited considerably through meetings and discussions with and suggestions
by the Technical Advisory Committee (TAC). The TAC consisted of Representatives of
the Bureau of Beaches and Coastal Systems of the Florida Department of Environmental
Protection, Palm Beach County, Broward County, City of Boca Raton, City of Deerfield
Beach, and Hillsboro Inlet District.











12.0 REFERENCES


Beachler, K.E. (1993): The Positive Impacts to Neighboring Beaches From the Delray
Beach Nourishment Program, Proceedings, Sixth National Conference on Beach
Preservation Technology: The State of the Art of Beach Nourishment, Vol. 6, 223-238.

Coastal Planning and Engineering, Inc. (2002) "Boca Raton Inlet Management Plan",
Submitted to the City of Boca Raton.

Coastal Planning and Engineering, Inc. (2002) "2002 Post Construction Monitoring
Report of the Boca Raton Inlet and Adjacent Beaches", Boca Raton, Florida.

Coastal Planning and Engineering, Inc. (1991) "Boca Raton Inlet and Adjacent Beaches
Management Program, Status Report No. 9", Boca Raton, Florida.

Dean, R.G. (2002) "Beach Nourishment: Principles and Applications", World Scientific
Press, 399 pages.

Strock, A.V. and Associates, Inc. (1979) "Preliminary Report: Boca Raton Inlet and
Adjacent Beaches for the City of Boca Raton".

University of Florida Department of Coastal and Oceanographic Engineering Archives,
Aerial Photographs for Boca Raton Inlet and Hillsboro Inlet.

U. S. Army Corps of Engineers (1985) "Beach Erosion Control Project for Palm Beach
County, Florida General Design Memorandum with Palm Beach Harbor Section 111
Report and Environmental Impact Statement", Jacksonville District, In Draft Form.

Walton, T. L. (1976) "Littoral Drift Estimates Along the Coastline of Florida", Florida
Sea Grant Program Report No. 13.







APPENDIX A

A SERIES OF 18 PHOTOGRAPHS OF BOCA RATON INLET

1936 TO 1995








APPENDIX A
A SERIES OF 18 PHOTOGRAPHS OF BOCA RATON INLET
1936 TO 1995

1 A.O INTRODUCTION

This Appendix presents a series of 18 aerial photographs of Boca Raton Inlet extending
from February 22, 1936 to February 6, 1995. The dates of the individual photographs are
listed in Table A.1. The photographs are from the Coastal Engineering Archives at the
University of Florida.

Table A.1

Dates of Aerial Photographs Included in This Appendix

Figure Number Date of Photograph Figure Number Date of Photograph
A.1 February 22, 1936 A.10 November 21, 1968
A.2 May 3, 1940 A.11 November 6, 1969
A.3 March 9, 1945 A.12 August 17, 1970
A.4 November 22, 1945 A.13 March 8, 1971
A.5 August 21, 1959 A.14 April 12, 1973
A.6 October 21, 1961 A.15 April 4, 1975
A.7 February 21, 1964 A.16 April 23, 1986
A.8 March 13, 1965 A.17 February 11, 1991
A.9 February 14, 1968 A.18 February 6, 1995




































Figure A.1 Aerial Photograph of Boca Raton Inlet. February 22, 1936.






















































Figure A.2 Aerial Photograph of Boca Raton Inlet. May 3, 1940.




50






















































Figure A.3 Aerial Photograph of Boca Raton Inlet. March 9, 1945.



51





















































Figure A.4 Aerial Photograph of Boca Raton Inlet. November 22, 1945





52

















































Figure A.5 Aerial Photograph of Boca Raton Inlet. August 21, 1959.












53























































Figure A.6 Aerial Photograph of Boca Raton Inlet. October 21, 1961.




54
























































Figure A.7 Aerial Photograph of Boca Raton Inlet. February 21, 1964.



55























































Figure A.8 Aerial Photograph of Boca Raton Inlet. March 13, 1965.



56
























































I ;;'E: "M I

Figure A.9 Aerial Photograph of Boca Raton Inlet. February 14, 1968.


57
























































Figure A.10 Aerial Photograph of Boca Raton Inlet. November 21, 1968.


58























































Figure A. 11 Aerial Photograph of Boca Raton Inlet. November 6, 1969.



59

























































Figure A.12 Aerial Photograph of Boca Raton Inlet. August 17, 1970.


60























































Figure A.13 Aerial Photograph of Boca Raton Inlet. March 8, 1971.




61

























































Figure A.14 Aerial Photograph of Boca Raton Inlet. April 12, 1973.


62

























































Figure A. 15 Aerial Photograph of Boca Raton Inlet. April 4, 1975.


63


























































Figure A.16 Aerial Photograph of Boca Raton Inlet. April 23, 1986.


64
























































Figure A.17 Aerial Photograph of Boca Raton Inlet. February 11, 1991.



65
























































Figure A. 18 Aerial Photograph of Boca Raton Inlet. February 6, 1995.


66







APPENDIX B

SEDIMENT BUDGET METHODOLOGY








APPENDIX B


SEDIMENT BUDGET METHODOLOGY




B.1.0 General

A sediment budget is simply a formal procedure to account for the sediment inflows into
and outflows from and additions to a system to result in volume changes within the
system. The degree to which the sediment budget can be developed and checked depends
on the amount of data available. It will be shown that of the three segments considered
(Figure B.1), only Segment 2 has sufficient information to check against the documented
volume changes based on survey data if the bar bypassing contributions are negligible.
For Segments 1 and 3, there is only sufficient information to quantify the net annual
sediment transport into and out of Segments 1 and 3, respectively.

B.1.1 Sediment Budget Relationships

Referring to Figure B.1 for terminology, the equations for the sediment budgets for the
three segments are:

Segment 1: For this case, all of the quantities are known to allow calculation of the net
transport into the segment, QINI. The equation defining QIN. is:

QeN,I = QB,BR + (dVdt) QNouR, (B.1)


in which QBP,BR is the average rate of bypassing at Boca Raton Inlet during the period of
interest, (dV/) is the average rate of volumetric increase within Segment 1 and
QNOUR,1 is the average volumetric rate of nourishment in Segment 1 during the period of
interest.

Segment 2: For Segment 2, all of the information is available to balance and check the
budget assuming negligible bar bypassing. Thus, whether or not the sediment balances
provide a measure of the confidence that should be placed in the data and assumptions.
The sediment budget for this Segment 2 is:
Q (dV) +Q l (B.2)
QBP,BR -QBP,HI -( dt 2) + QNR,=0 (B.2)

and where the "?" signifies that if the equation doesn't balance, this is a measure of the
uncertainty in the sediment budget.











dV/dt



QNOUR


Boca Raton


QBP


Hillsboro Inlet
-QBP


dV/dt


QNOUR

--^--Q


Segment 1










Segment 2











Segment 3


Figure B.1 Segments Used in Sediment Budget Analysis.
Note: Dates Shown are for "Early" Period Considered in Establishing Sediment Budgets.









Segment 3: For this case, all of the quantities are known to allow calculation of the net
transport out of the segment, Qour,3. The equation defining QOUT,3 is:

Qour,3 = QBP,,+ QUR.3 ( dVtd) (B.3)

A caveat to the discussion above is that if natural "bar" bypassing occurs around the two
inlets, the quantities QBP,BR and QBP,HI are to be interpreted to include the bar bypassing.

B.1.2 Global Sediment Budget

The methodology presented to this point has concentrated on the sediment inflows and
outflows of the individual segments considered. A so-called "global sediment budget"
can also be developed which allows calculation of the difference between the net
transport into and out of the entire system. It is anticipated that the volume of sediment
entering and leaving the entire system considered here (Segments 1, 2 and 3) will be
approximately equal under natural conditions. Combining Equations (B.1), (B.2) and
(B.3),

AQ = QN-Qo == (QNOUR) (B.4)


The advantage of this global consideration is that bypassing (hydraulic and natural) at the
two inlets do not appear in the formulation since they are internal to the entire system
under consideration. The disadvantage is that only an estimate of the difference in
transport in and out of the system is determined.

In the case under consideration, it is anticipated that AQ will be greater than zero since
the Delray Beach nourishment project immediately to the north of the system under
consideration will induce sediment transport into the system over and above the natural
sediment transport.








APPENDIX C

PLOTS OF SELECTED PROFILES CORRESPONDING TO
LONG PROFILE MONUMENTS FOR EARLIEST SURVEY
FROM R-189 IN PALM BEACH COUNTY TO
R-55 IN BROWARD COUNTY










R-189
20
.... ....... ....... .. ..... ............................................................. 1975 ... ..
1990
1 0 - - - - - . . ... . . . . . . . . .-- --- .....2000.
-------r 2001




1o. 0O ..... ......... .. :. ............... ............... ................ ...... ... ............... ....... .........



S-20 ...........................


0 :.... .

0 5



-1 .... ........ .. .. ......... .. .......... ..... ............ ... ..... ... .... ........ .. ............ .
-50 ..... .. ... ..... ..... ...... .. ....


-60
0 1000 2000 3000 4000
Distance (ft)

Figure C.1. Plot of Profiles for Monument R-189 in Palm Beach County.


R-192
20
S.. 1975
1990
10 --- 2000






-lo

~ -20


0
I ................ ... ..........*..............................
-30
0


ID ... .. .. .... .... .... .. .... ....... .... .. . . .. ...... .




-60
0 1000 2000 3000 4000
Distance (ft)

Figure C.2. Plot of Profiles for Monument R-192 in Palm Beach County.














20


10


0

0
-10
4-l


S-20


C -30
0

0 -40
i-5

-50


R-195


0 1000 2000 3000 4000
Distance (ft)

Figure C.3. Plot of Profiles for Monument R-195 in Palm Beach County.


R-198
20












c-30
-2 0 - I. . . ....... -

4-0










0 1000 2000 3000 4000
Distance (ft)

Figure C.4. Plot of Profiles for Monument R-198 in Palm Beach County.
0 0 ................ .. ....................................
4- **** ******* *******^ *************** ******* **** _
0 U--------------------------
II Ij" ;.. ;













20


10
R-201



0 : 0: ---- 1975


.10 -







-ao20
Z .20 ......... ......


3 ....... ...... .. ..... .......... .............................. ... ....... ......... I....



-50





-60
0 1000 2000 3000 4000
Distance (ft)

Figure C.5. Plot of Profiles for Monument R-201 in Palm Beach County.


R-204
20
.. ............... .................... .......... ...... ....... 1975 ..
S ... .. ---- 2000--
10 . . .


o u \.


4o


S-20


c -30
0

-40






-60
0 1000 2000 3000 4000
Distance (ft)

Figure C.6. Plot of Profiles for Monument R-204 in Palm Beach County.











R-207


-". ........... -.---------.......N...............


z -
1 0 .. .


. . ... .. . . . . . . . . . ... . . . . . ..
S-20



-2 0 . . .. i . . . .. . . . .. . . .. . .. ... . . .. .. .. . .

G 3C. .3 0 ..... .. . .... ... ..... ... ........... .. ................ ............... . .............. ........ ..
E -30
6o



-60 .....-
-50


-W0
0 1000 2000 3000 4000
Distance (ft)

Figure C.7. Plot of Profiles for Monument R-207 in Palm Beach County.
R-210
20
S: ....... 1975
1990
2001
.. ....... .... ............ ...... ....... ............... ........ ............. ............. :-....- ..........

- --------'-,,,

-310 ... : :


0




I -40 ... ...
0 .0 .. .......... ; ............ ... ....... ............... ....... .. ........ I ................





-.o -
.............. .. ............... i ............. ............... ............... ......... ... ......... ..............

-60
0 1000 2000 3000 4000
Distance (ft)


Figure C.8. Plot of Profiles for Monument R-210 in Palm Beach County.














R-213


-10
> . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . .







-0
S. .. .... . . . .. . . . . . . . .. . . . . . . .. ... . . . . - . . . . .. . . . . .. . . . . . . .
-60 .... : .....








2 I ... ..




0 1000 2000 3000 4000
Distance (ft)
Figure C.9. Plot of Profiles for Monument R-213 in Palm Beach County.
0R-216
. . . . . .. . . . . . .. . . .. .. . .. . . . . . . . . . .. . .. -.. . . .. . ... . .. . .. . .. . . .













-0 ... 1990
S . . . ....... .... .. .. .. .. .... ........







S ----................ .....'-. ............... ------ ............... --- .......... ................ ---- ...............----




-2001
20

10 3 .. .. .



















-60
0 1000 2000 3000 4000
Distance (ft)


Figure C.10. Plot of Profiles for Monument R-216 in Palm Beach County.
Figure C. 10. Plot of Profiles for Monument R-216 in Palm Beach County.


















00
10 : .--.,', : ....... : ...... ......... ..

.. ........ ............ ....... ........ ............... ............................



........... .. .. ........ ....... ... ... .... ....... -.:.. ...... ......... ............... ... ... .......... ................
z-
-10
4-2
a




a i ""

0 1000 2000 3000 4000



-60
0 1000 2000 3000 4000
Distance (ft)

Figure C.11. Plot of Profiles for Monument R-219 in Palm Beach County.


0

-10


S-20



0

. -40
-0


0 1000 2000 3000 4000
Distance (ft)

Figure C.12. Plot of Profiles for Monument R-222 in Palm Beach County.















0
0 i
:o -- :-----; - : -- :: .. ...... --
...... .. ..... ............... ..... -------------- ............. ... .. .
. . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . .



0








)0 I .

-- - -- - ........---...........................-----


0 1000 2000 3000 4000
Distance (ft)

Figure C. 13. Plot of Profiles for Monument R-1 in Broward County.


4000


1000 2000 3000

Distance (ft)


Figure C.14. Plot of Profiles for Monument R-3 in Broward County.


































0 1000 2000 3000 4000
Distance (ft)

Figure C. 15. Plot of Profiles for Monument R-6 in Broward County.


u : ------- 1997


O 10 ..... .. ....... .... ..:.............. .............. ............----- .. ---.... ---- ....... ........ .............
------ 2002



.......... ...............


- 2 0 .............. ................ -.............. .i ........ ~I. . ................... . . ......... .

e ,0- -30 i. i. i. i. ...... .. ........... : ... ......... .. ......: ......... .............. ........ ... .. ..............
C : ... ..-... ..... .. .. ............... ..............
0



S. ,- 1

-5 o . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . .. . .. . . . . . . . . .. . .. . . . . . . ..
-.50 . . .. ........

-60
0 1000 2000 3000 4000
Distance (ft)

Figure C.16. Plot of Profiles for Monument R-9 in Broward County.
















S10


> o
0
Z
O -10




0
, -20


^ -30
o
O -40

iu -


R-12


0 1000 2000 3000 4000

Distance (ft)

Figure C.17. Plot of Profiles for Monument R-12 in Broward County.


R-15


0 -10 ....... ..... i!....... ., '" .............. ........ ..... ......................... .................. ..............



-60 ---------------------------:--I------i---
. ..--- 19 i... ....7








........... ...... ... ..... . ........... .... ... ................ ...........



0.......... .. ..... ............ : .




-60
0 1000 2000 3000 4000

Distance (ft)

Figure C. 18. Plot of Profiles for Monument R-15 in Broward County.















- 10
10

Z
> 0
z
O -10

S -20
(0

-30
0
( -40

-50

-60


R-18


1000 2000 3000
Distance (ft)


Figure C.19. Plot of Profiles for Monument R-18 in Broward County.


R-21


4000


0 1000 2000 3000

Distance (ft)


Figure C.20. Plot of Profiles for Monument R-21 in Broward County.












R-24
20


10 19........................................ ..................................... 1993 ......
. . . ....... ,........ .............. ............. .............. .............. .... .. ........ 1 ......
-10 \ : : ..- 1997 .





- 1 0 . . .. . . . . . ... . . .... . . . . . . .. . . . . ... . . . . . . . . . . . . . . . .. . . . .
-20




- 5 0 . . . . . . ... . . . . . . . . . . . . .. . . . . . . . . . . .. . . . . . . . . . . . . . . . ..
-30 ........... ....... ..'..-.-.-..... '..........---- --- ---- -
-40




-60
0 1000 2000 3000 4000
Distance (ft)



Figure C.21. Plot of Profiles for Monument R-24 in Broward County.


1,

> 0







0


5 -40
0


i4)


R-27


0 1000 2000 3000 4000

Distance (ft)

Figure C.22. Plot of Profiles for Monument R-27 in Broward County.




82














20

10

> 0
0
z
o -10

, -20

-30
C
0
-o
( -40

S-50


-60


R-30


1000 2000 3000
Distance (ft)


Figure C.23. Plot of Profiles for Monument R-30 in Broward County.


R-33


I *"V ::---- 1997
...o.. .. +. ... ||........ .......... ..... .... ...... . .............. . .. ...... I .. ....
0 I



. . . .. ... .. ... .. .. . . . .... .... . . . . . .. .. .. ......, .. .. . ... ... ... ... .. .

S-20







-so
3 ..... ... ... .. ... ..... ..... ......... .. .. .. . ... ...... ...... ............
. 0 .. .
0 .... .... ............ ............. ... ....





-60
0 1000 2000 3000 4000
Distance (ft)

Figure C.24. Plot of Profiles for Monument R-33 in Broward County.











R-36


i






4000


1000 2000 3000


Distance (ft)

Figure C.25. Plot of Profiles for Monument R-36 in Broward County.


R-39


4000


0 1000 2000 3000
Distance (ft)


Figure C.26. Plot of Profiles for Monument R-39 in Broward County.


IU

Q
> 0
z
o -10


-so
ao
0-20



a)
-30
0
( -40
0 _










R-42


0 1000 2000 3000 4000
Distance (ft)

Figure C.27. Plot of Profiles for Monument R-42 in Broward County.


R-45


0 1000 2000 3000 4000
Distance (ft)

Figure C.28. Plot of Profiles for Monument R-45 in Broward County.












R-48
20
20-- ---1976
V, 1993
. ----- 219937
1 0 : ..1 .^ . ... i . .......... ...... i .. . ..... .... ....... .. : .. ... ........ . .. .... ..... 2. .2
> o

z
-10 --------------- ....







O C .3 .. .......... ............................. . .......... .. i .............. .............. ............. ............. .
_ 0 . ..... ........... .. .. . .. ..... ..... ............ ..... ......... .. ........



........ .......---...................---- ------ '------........
-20 -


















R-51
20 :
o

S......-40 ......
















S..... ...................... ............. ..............,............................. / 1 993 ......
S: . .. ... ... ......... ... ............ ... ..... ....... .. .......... . ... .. ------- 2002 1 ......
S-0
0 1000 2000 3000 4000
Distance (ft)















0.-10 .: ..... . ........ ......... ... ............... ...........................
Figure C.29. Plot of Profiles for Monument R-48 in Broward County.


R-51
20


: \ 1976
--1997200

>0







.... .... . ..... . ... ... . .. . - - .. .. ..... ........ ... ....... .... ... .. .........
z



S -20

-30
C


0 .
-5 0 .... .. .. . . .. . . .* . . ..... .. ............. .. ..... .


-60
0 1000 2000 3000 4000
Distance (ft)

Figure C.30. Plot of Profiles for Monument R-51 in Broward County.












R-54
20
............................. .... .... ..... ............... .................... .......... .......
S. ... .199731
S: : : : -- 1997
2002
- 1 0 \ : . ........... ..... .... ... ... ..... .. ...... ...... .."............. .......... ... .... ... . .. . ......




: -20 : ,



20
>~~~~ ~.. ------------------------------





-30







-60
- 0 ... ... ..... .. ... .........-. ... .. . ... .......... .............. ...
-3 0 .............. .............. ..... .. ....... ..... ..... . ......

0 . . . . . . . . . . .... . . . . -.. . .. . .. . . . . . . . . . . . . . . . . .. .... . . . . . . .. .



.......... .............. ... ........... ..... ............................. ........ .............

-60 I-I -I-
0 1000 2000 3000 4000

Distance (ft)

Figure C.31. Plot of Profiles for Monument R-54 in Broward County.




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