• TABLE OF CONTENTS
HIDE
 Front Cover
 Title Page
 Advance summary
 Introduction and Description of...
 Wave data analysis
 Sediment considerations
 Settlement and scour considera...
 References
 Appendix I
 Appendix II
 Appendix III
 Appendix IV
 Appendix V






Group Title: UFL/COEL (University of Florida. Coastal and Oceanographic Engineering Laboratory); 94/002
Title: Performance of the P.E.P. reef installation, town of Palm Beach, Florida
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00084996/00001
 Material Information
Title: Performance of the P.E.P. reef installation, town of Palm Beach, Florida first six months results
Series Title: UFLCOEL-94002
Alternate Title: Performance of the Prefabricated Erosion Prevention reef installation
Physical Description: 1 v. (various pagings) : ill. ; 28 cm.
Language: English
Creator: Dean, Robert G ( Robert George ), 1930-
Dombrowski, Michael R
Browder, Albert E
University of Florida -- Coastal and Oceanographic Engineering Dept
Publisher: University of Florida, Coastal & Oceanographic Engineering Dept.
Place of Publication: Gainesville Fla
Publication Date: 1994
 Subjects
Subject: Artificial reefs -- Florida -- Palm Beach   ( lcsh )
Shore protection -- Florida -- Palm Beach   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Includes bibliographical references.
Statement of Responsibility: Robert G. Dean, Michael R. Dombrowski, Albert E. Browder.
General Note: "February 1994."
Funding: This publication is being made available as part of the report series written by the faculty, staff, and students of the Coastal and Oceanographic Program of the Department of Civil and Coastal Engineering.
 Record Information
Bibliographic ID: UF00084996
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 32781482

Table of Contents
    Front Cover
        Front Cover
    Title Page
        Title Page
    Advance summary
        Page 1
        Page 2
    Introduction and Description of monitoring program
        Page 3
        Page 4
        Page 5
        Page 6
    Wave data analysis
        Page 7
        Page 8
        Page 6
        Page 9
        Page 10
        Page 11
        Page 12
    Sediment considerations
        Page 13
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
        Page 20
        Page 21
        Page 22
        Page 23
        Page 24
        Page 25
    Settlement and scour considerations
        Page 26
        Page 27
        Page 28
        Page 29
        Page 30
        Page 31
        Page 32
        Page 33
        Page 25
    References
        Page 34
    Appendix I
        Page I
        I - 2
        I - 3
        I - 4
        I - 5
        I - 6
        I - 7
        I - 8
        I - 9
        I - 10
        I - 11
        I - 12
        I - 13
    Appendix II
        Page II
        II - 2
        II - 3
        II - 4
        II - 5
        II - 6
        II - 7
        II - 8
        II - 9
        II - 10
        II - 11
        II - 12
        II - 13
        II - 14
    Appendix III
        Page III
        III - 2
        III - 3
        III - 4
        III - 5
        III - 6
        III - 7
        III - 8
        III - 9
    Appendix IV
        Page IV
        IV - 2
        IV - 3
        IV - 4
        IV - 5
    Appendix V
        Page V
        V - 1
Full Text




UFL/COEL-94/002


PERFORMANCE OF THE P.E.P. REEF INSTALLATION
TOWN OF PALM BEACH, FLORIDA
FIRST SIX MONTHS RESULTS






by



Robert G. Dean
Michael R. Dombrowski
and
Albert E. Browder




February, 1994




Sponsor:

Department of Environmental Protection,
State of Florida
and
Town of Palm Beach, Florida












PERFORMANCE OF THE P.E.P. REEF INSTALLATION
TOWN OF PALM BEACH, FLORIDA
First Six Months Results






Robert G. Dean


Michael R. Dombrowski


Albert E. Browder











University of Florida


Coastal & Oceanographic Engineering Department


Gainesville Florida


February, 1994









ADVANCE SUMMARY


GENERAL
This report presents the results from the Prefabricated Erosion Prevention (P.E.P.) Reef monitoring program
extending from July 1992 to December 1993. Construction of the reef commenced in July 1992 and 56 units had
been placed by mid-August 1992. Hurricane Andrew impacted the area in late August 1992, after which a single
unit was placed, bringing the total number in August 1992 to 57. Following placement of the original 57, settlement
of the units was documented. The hurricane and subsequent settlement survey caused a hiatus in the installation
which recommended in May 1993 and was completed in August 1993. Profile and offshore surveys are available
for July 1992, April 1993, August 1993, and December 1993. Wave gages are located landward and seaward of
the reef system and complete data are available and have been analyzed from October through December 1993.
Other measurements available and reported herein include settlement of the P.E.P. units and results from scour rods.
Various types of analysis methods were applied to the data to provide the clearest possible understanding and
interpretation of the reef effects: results of these analyses are summarized in the following paragraphs.


SETTLEMENT OF UNITS
The first 57 units installed have settled an average of 2.8 feet and the remaining 273 units, installed approximately
one year later have settled an average of 1.4 feet.


SCOUR
The scour rods (located near the reef) indicate scour ranging from 0.4 foot to in excess of 2.5 feet.


WAVE TRANSMISSION
The wave transmission coefficients are less (the wave height reductions are greater) for the larger waves and the
coefficients range from 0.65 (larger waves) to 0.85 (smaller waves). These transmission coefficients indicate greater
energy reduction than is suggested from laboratory tests and it is believed that some of the reduction is due to wave
energy dissipation that would occur in the absence of the reef (the inshore and offshore gages are in water depths
of approximately 6 and 12 feet,respectively).


SEDIMENT VOLUME CHANGES
The volumetric change patterns are complex and overall reflect continual net losses within the 4000 feet confines
landward of the reef and net gais within the 2000 feet segments north and south of the reef and landward of an
extension of the reef axis. The rate of the loss within the reef confines is greater for the last intersurvey interval,
a period when the average wave conditions were fairly energetic. Seaward of the reef, losses have occurred within










the reef confines and 2000 feet north and south of the reef. Over the entire monitoring period, deposition has
occurred both landward and seaward of the reef within the southerly 600 feet of the reef confines. Landward of
the reef extension, this deposition extends as far south as the survey data are available (1600 feet south of the reef),
well beyond the anticipated influence of the reef. These deposition patterns are consistent with the following
mechanism which is presented here as a preliminary hypothesis. Water is carried over the reef by wave mass
transport, a well-understood phenomenon. The full seaward return of this water is impeded by the presence of the
reef and a portion of this water is directed as a longshore current which increases with distance. This current carries
sand which is deposited upon reaching the ends of the reef where the current diminishes as it is no longer confined.
This deposited sand results in an excess of sand in these profiles and a portion is driven ashore by the waves,
resulting in a locally wider beach.


SUMMARY STATEMENT
The results and interpretation presented herein are based on monitoring data which encompasses only four months
after full installation of the reef. Interpretations are therefore considered preliminary and subject to modification
based on future monitoring results.


ACKNOWLEDGEMENTS
The authors appreciate the sponsorship of this study provided by the Department of Environmental Protection and
the Town of Palm Beach and the logistical support and participation in field studies by their representatives. Sea
Systems, Inc. of Pompano Beach, FL., conducted the survey profiling in a responsive and professional manner.









INTRODUCTION


The P.E.P. Reef installation, the subject of this report, is located off the Midtown section of the Town of Palm
Beach, roughly 4.5 miles south of the Port of Palm Beach entrance (Figure 1) in a water depth of 9.4 feet NGVD
(Figure 2). The overall length of the reef is 4176 feet including a gap of 216 feet near the north end. The reef
was installed with the expectation that it would both provide a wider beach and considerably reduce wave action.
In order to evaluate the performance of the reef vis a vis the expectations, a multi-faceted monitoring program is
being carried out. The program includes biological and physical elements. This report centers on the data relating
to the physical performance of the reef as of the latest profile survey, conducted in December, 1993.


This report is organized as follows. The following section describes the physical monitoring program. The next
three sections present findings from analysis of the data. These findings are intended to present results without any
interpretation. The seventh section presents our preliminary interpretation of the data, a process that clearly
introduces an element of judgement. Where possible the degree of uncertainty required in the interpretation will
be presented. The final section presents the conclusions developed to date.


DESCRIPTION OF THE MONITORING PROGRAM

As noted, the program includes both physical and biological elements. The physical aspects are described below.


WAVE DATA ANALYSIS
To monitor the effectiveness of the reef in reducing incident wave energy at the site, wave gages have been installed
on either side of the reef to measure wave height and direction and current magnitude and direction. The data from
these gages are analyzed and tabulated in the Florida Coastal Data Network format.


PROFILE AND BREAKWATER UNIT SURVEYS
As shown in Figure 3, the profile survey plan includes a total of 75 profile lines. Most of these lines are surveyed
on a quarterly basis by a combination of land surveying techniques, swim surveys in which a level and rod technique
are employed and farther offshore, using standard fathometer measurements. The swimming portion of the surveys
extends at least 50 feet seaward of the reef units. The differences between the quarterly and annual surveys are that
the quarterly surveys extend offshore only 1200 feet as compared to 3,500 feet for the annual surveys and the
Department of Environmental Protection (DEP) surveys are extended to 6,500 feet seaward for the annual surveys.


In addition to surveying the profiles, elevations are taken on the north, middle and south of the crest of each
breakwater unit in order to document any settlement of the units.










Net Longshore
,diment Transport






Port of
Palm Beach
/ Entrance


C-7


O 0


-z

I PEP Reef 4176ft









0 5 Miles
-6Imi 6 i


BREAKERS RD.


R9




-
O
m


U.
0
IL.

0
I-


R105


EXISTING SHOREUNE



GAP (216 FT) FOR AT&T CABLES


PEP REEF 4216 FT LONG,
' (INCLUDING GAP) IN WATER DEPTH
OF9.5 FTNGVD

1- DIRECTIONAL WAVE GAGES













0 5000
SCALE(FT)


Figure 1 Location Map Showing Proximity
to Port of Palm Beach Entrance


Figure 2 Location Chart of Monitoring Area


Blue











-..- N 85E



- "- __ Most Northerly Lines Except
--. 1 400' for Those at DNR Monuments
7- 2.N 980E
7222'-N 900E


1 300'
2 150'


8-75' ,- 85E
--' "-.100' 085E
8-75' ,.--- .. N 80E
-- BREAKWATER
....N 800E
-"" 9-200'
4 -15... N 800E
A-1 0AUo' _.N 750E


NOTES:
All Profile Lines at 90 Azimuth Except, as Noted,
for 12 of the 15 Lines From DNR Monuments
Total of 75 Lines. (DEP Monuments Only Surveyed
Annually, Others Quarterly).


- .5 Denotes 6 Spaces at 75 ft
Between Profile Lines
10 -200' N 900E
.N 80E
SMost Southerly Line Except
--- for Those at DNR Monuments


3 5000ft


APPENDIX B


0
O
I










SCOUR STUDIES
Twenty-eight scour rods have been installed to establish the intersurvey depths of scour. Referring to Figure 4,
these rods are copper tubes, six feet long, and are jetted into the bottom with a PVC cap on the top of the tube.
A washer is placed around the tube on the sand surface. The tops of the PVC caps were leveled in at the time of
installation. During erosional events, the washer follows the sand horizon and is left at the elevation of the maximum
erosion. Alternatively, if the washer has settled to a depth making its retrieval impossible by this method, its
position is established by "sounding" with a small diameter rod and a new washer installed.


SAND SAMPLES
Sand samples are collected annually in the vicinity of the reef. It is anticipated that the analysis of these may
provide a basis for determining sources of any sand that accumulates in a particular region.


WAVE DATA ANALYSIS


One of the main objectives of a shore parallel breakwater is to reduce wave energy transmitted over the structure.
This is accomplished by reflection of incident wave energy as well as dissipation of energy over the structure.


To monitor the effectiveness of the reef in reducing wave energy, two subsurface pressure-velocity gages were
installed. These gages are approximately 50 feet on either side of the structure, and are located 1,500 north of the
south end of the reef. The nearshore gage was installed in 6.1 ft water depth, and the offshore gage in 13.5 ft
depth. The gages report via telephone modem to the Coastal & Oceanographic Engineering Laboratory (COEL)
in Gainesville, FL. The incoming data are then analyzed and processed in the Florida Coastal Data Network
(FCDN) format. Additional analysis is conducted to study individual spectra, single wave tracking, and transmission
coefficient determination.


The gages collect data hourly, recording average pressure and two horizontal velocity components. Every sixth
hour, a full 1,024 second pressure/velocity record is recorded. These data are collected daily and stored in the
COEL database. Reliable data have been collected from September through the present and are shown in graphical
form in Appendix I.


SPECTRAL ANALYSIS
Following the standard FCDN format, the energy spectrum of a 1,024 second record is analyzed using a Fast
Fourier Transform (FFT) routine. The FFT uses 128 second blocks with a 50% overlap to obtain an average
spectrum for the 1,024 second record. The spectrum is then smoothed using a moving five-point average. The









10' 10'


26 27 28


5'
5'
2021
* *


19
18


0
14 15




10 11
10 11


I I







67
*5
*4


CONTROL POINT 500' NORTH
OF BREAKWATER


N.T.S.


a 0
2223
NORTH END OF BREAKWATER

AT&T SUBMERGED LAND EASEMENT
__216' GAP


16 17




--- -BREAKWATER CENTER LINE


SOUTH END OF BREAKWATER

**
89





3
* CONTROL POINT 500' SOTH
OF BREAKWATER


COPPER PIPE
LOOSE WASHER
(INmAL PosmoN)

WASHER AFTER SCOUR
/ SCOUR DEPTH




SCOUR ROD (TYPICAL)
TOTAL = 28


Figure 4 Scour Rod Arrangement.









significant wave height is computed from the spectrum according to Equation (1).


H,= 4 E ( f) df(1)


H, = significant wave height (average of highest 1/3 waves in record), E(f) = spectral density at frequency.
The modal period Tm is taken as the period associated with the frequency corresponding to the largest spectral
density. The modal wave direction is determined by the same procedure as the FCDN format, and the reader is
referred to Coastal & Oceanographic Engineering Department (1993), for the development. The method uses a
directional spectral model that represents the directional distribution of energy by a symmetric cosine-power
function. The peak of that function is taken as the predominant direction to which waves travel. The two
directional current meter is used to determine the mean currents and directions as plotted in Appendix I.


Several representative spectra are presented here. Figures 5 and 6 depict the spectral density for representative
records taken during November and December. The plots show the offshore and nearshore spectra, as well as a
predicted shoaled spectra based on the offshore gage. This prediction uses a linear theory to shoal the individual
frequency components from the offshore to the nearshore depth. It assumes normal wave incidence at each gage.
As shown in Figures 5 and 6, the nearshore measured spectral density is less than that predicted by linear shoaling
and is less than or equal to that of the offshore gage. Table 1 lists the significant wave heights computed for the
figures for the offshore, nearshore, and shoaled offshore records.


WAVE HEIGHT REDUCTION
To quantify the reduction of wave energy (and hence wave height) a transmission coefficient must be determined.
These coefficients were determined as follows in equation (2),

H
Kt = Snearshore (2)
offshore shoaled


where K, = transmission coefficient. Figure 7 presents transmission coefficients for the months of October,

Table 1 Representative Significant Wave Heights (ft)

Date H, Offshore H, Nearshore H, Shoaled K

10/24/93 2.46 2.26 2.82 0.80

11/26/93' 4.26 3.51 4.86 0.72

12/18/93 3.67 3.38 4.33 0.78
Thanksgiving Weekend Storm Condition










SCOUR STUDIES
Twenty-eight scour rods have been installed to establish the intersurvey depths of scour. Referring to Figure 4,
these rods are copper tubes, six feet long, and are jetted into the bottom with a PVC cap on the top of the tube.
A washer is placed around the tube on the sand surface. The tops of the PVC caps were leveled in at the time of
installation. During erosional events, the washer follows the sand horizon and is left at the elevation of the maximum
erosion. Alternatively, if the washer has settled to a depth making its retrieval impossible by this method, its
position is established by "sounding" with a small diameter rod and a new washer installed.


SAND SAMPLES
Sand samples are collected annually in the vicinity of the reef. It is anticipated that the analysis of these may
provide a basis for determining sources of any sand that accumulates in a particular region.


WAVE DATA ANALYSIS


One of the main objectives of a shore parallel breakwater is to reduce wave energy transmitted over the structure.
This is accomplished by reflection of incident wave energy as well as dissipation of energy over the structure.


To monitor the effectiveness of the reef in reducing wave energy, two subsurface pressure-velocity gages were
installed. These gages are approximately 50 feet on either side of the structure, and are located 1,500 north of the
south end of the reef. The nearshore gage was installed in 6.1 ft water depth, and the offshore gage in 13.5 ft
depth. The gages report via telephone modem to the Coastal & Oceanographic Engineering Laboratory (COEL)
in Gainesville, FL. The incoming data are then analyzed and processed in the Florida Coastal Data Network
(FCDN) format. Additional analysis is conducted to study individual spectra, single wave tracking, and transmission
coefficient determination.


The gages collect data hourly, recording average pressure and two horizontal velocity components. Every sixth
hour, a full 1,024 second pressure/velocity record is recorded. These data are collected daily and stored in the
COEL database. Reliable data have been collected from September through the present and are shown in graphical
form in Appendix I.


SPECTRAL ANALYSIS
Following the standard FCDN format, the energy spectrum of a 1,024 second record is analyzed using a Fast
Fourier Transform (FFT) routine. The FFT uses 128 second blocks with a 50% overlap to obtain an average
spectrum for the 1,024 second record. The spectrum is then smoothed using a moving five-point average. The





















101-


n


0.0


0.2


f(Hz)


0.3


0.5


Figure 5 Example Spectra from Offshore, Nearshore, and Shoaled Offshore Records.
November 26, 1993, 6:00 PM.


0 II I I '1............
0.0 0.1 0.2 0.3 0.4 0
f(Hz)
Figure 6 Example Spectra from Offshore, Nearshore, and Shoaled Offshore Records.
December 18, 1993, 6:00 PM.


II
SI
I I
i -- offshore
i ....... nearshore
I ---- shoaled offshore
I
I I
It


I I






i .. \
,


.5


I I












+4 +
c -to :















October


October December~


11 26


November


10 25
date


10 25


Figure 7 Wave Transmission Coefficients Based on Significant Wave Heights for October, November,
and December, 1993.


November, and December, 1993. The average value of K, for October was 0.83, for November was 0.674, and
for December the average value was 0.74. The plots indicate a fair amount of scatter, however the average values
decrease as the wave heights increase, as in the winter months. The scatter can be partly explained by variations
in freeboard over the reef associated with astronomical and perhaps storm tides. As seen in the raw wave data,
wave heights in November were on average the largest of the three months. The reduction in transmission
coefficient seen in November is directly related to the increase in significant wave height (see Appendix I). This
is attributed to the behavior of wave transmission over a submerged barrier. This phenomenon is described in
greater depth in the wave tracking and interpretation portions of this report.


WAVE TRACKING
Transmission coefficients can also be determined by tracking individual waves over the reef from one gage to the
other. By performing an FFT on the 1024 second pressure record, transferring the Fourier coefficients to the
surface, then executing an inverse FFT on the new coefficients, the surface elevation records at each gage can be
obtained. These records are then used to measure the height of an individual wave as it passes each gage.



10


0.81-


0.61-


0.4 -


0.2 -


0.0


December









Results from this analysis are presented in two ways. The cumulative frequency distribution (CFD) of wave heights
describes the percentage of waves in a record that are less than a given height, H. Figure 8 depicts the CFD for
a record taken during December 18, 1993 (the spectrum for this same record is shown in Figure 6). Plotted in the
figure are the distributions for the offshore and nearshore gages, as well as a predicted nearshore distribution in the
absence of the reef, again predicted by normal-incidence linear shoaling theory. The three curves begin to diverge
at approximately 1.6 to 1.9 ft wave height. At a cumulative frequency of 0.5, the computed transmission coefficient
is 0.93. At a cumulative frequency of 0.9, the transmission coefficient equals 0.81. This indicates that the higher
waves are attenuated more sharply by the reef.


An alternative view of the CFD entails reduction of wave height for a given percentage of waves. For example in
Figure 8, 90% of the waves passing the offshore gage were 3.1 ft or less in height, whereas 90% passing the
nearshore gage were also 3.1 ft or less. Comparatively, the shoaled prediction shows that 90% of the waves would
have been 3.8 ft or less at the nearshore gage in the absence of the reef, again indicating the 81% transmission of
wave height at the 90% mark.


1 2 3
H(ft)


4 5 6


Figure 8 Cumulative Frequency Distribution of Wave Heights based on the Offshore, Nearshore, and
Shoaled Offshore Records. December 18, 1993, 6:00 PM.









From the surface elevation record, individual waves can be 'tracked' from gage to gage, thus determining a
transmission coefficient for an individual wave. Again to gain a fair comparison, the offshore waves are shoaled
to the nearshore depth and compared to that record. From this study the highest waves in a record can be tracked
and their transmission coefficients found. For the December 18, 1993, record discussed above thirteen high waves
were picked out of the record and had an average transmission coefficient of 0.76. A sample of the surface
elevation record is shown in Figure 9. The offshore record has been 'moved ahead in time' by 8.0 seconds to
match the nearshore record. This shift accounts for wave travel time between the wave gages.


CURRENTS
The gages also produce current magnitude and direction information. This is used to verify sediment transport
predictions and to determine the direction of wave travel, as described above. The raw data obtained are presented
in Appendix I. During the summer months, the average current is approximately 0.33 ft/s, directed north along
the beach. During periods of higher wave activity, i.e. the winter months, the currents average approximately 0.23
ft/s, but travel predominantly south along the beach. The reduction in current magnitude results from the opposition
of the natural current heading north and the wave-induced longshore current heading south during periods of higher
wave action. This higher wave activity comes predominantly from the northeast. The natural currents in the area
may be a result, in part, of the tidal flows in and out of the Port of Palm Beach Entrance.
3


2












-2 offshore + 8 s
....... nearshore


480 496 512 528 544
t(s)

Figure 9 Example of Wave Records from Nearshore and Shifted Offshore Wave Gages.
December 18, 1993, 6:00 PM.









SEDIMENT CONSIDERATIONS


EVEN/ODD ANALYSIS
Volumetric changes within the study area were analyzed using the even/odd analysis technique as presented in Berek
and Dean (1982) and Work and Dean (1990). The net volume changes along the study area can be divided into an
even function to document the net volume change that has occurred within the study area during a given time period
and an odd function that could represent the change due to longshore sediment transport. Although the interpretation
is subjective in nature, it can be a valuable tool in interpreting sediment transport erosional/depositional patterns.


The intent of the analysis is to document long term trends in the even and odd components and correlate these
results with those of the volume changes, scour rod monitoring and future sand tracer studies. The analysis and
preliminary interpretation of the first four surveys are presented in Appendix II.


ELEVATION CHANGES
The elevation changes both landward and adjacent to the reef will be presented in a quantitative as well as a
qualitative manner, as illustrated in Figures 10 to 13. The two-dimensional contour plots represent a change of
elevation (in feet) that occurred between monitoring surveys in which the areas of accretion (solid lines) and erosion
(dashed lines) are indicated.


July 1992 to April 1993
Figure 10 illustrates the elevation changes that occurred between the nine month period of July 1992 and April 1993
monitoring surveys. The short solid line at the 7,000 foot mark represents the 57 units (680 feet) that were in place
at the time of the April survey. The dotted line continuing to the north and the short segment to the south are the
remaining 273 units that were installed later. The accumulation of material is most prominent in the southern
portion of the study area. The area landward of the reef illustrates a shoreline response to a small perturbation in
the nearshore zone. The structure seems to have a shadowing effect on the nearshore zone which has formed a
depositional area. Both landward and seaward of the reef, deposition of approximately +2.0 feet occurred. The
accumulation of material extends a substantial distance south of this area. Material has accreted along the southern
shoreline as well as offshore. Most of the accumulation occurred along the existing dry beach with the greatest gain
of +3.0 feet along the beachface and tapering offshore.


The most noticeable characteristic change is the losses of material north of the existing reef. All along the shoreline
and much of the middle section of the study area had lost large amounts of material. The area landward of the reef
extension (dotted line) had between -1.0 and -4.0 feet of material removed, with the greatest losses at the pocket
beach at Clarke Avenue (3,500 foot location).











250 .. ..

150
Q) 50 % ::n:. '



10
















April 1993 to August 1993
-50 : 0 .


















The last 273 of the 330 units were installed approximately two weeks prior to the completion of the as-built, August
0
-100 """" '""i -'

-250 I


Figure 10 Isolines of Elevation Change ft), July 1992 to April 1993. Contours in 0.5 foot intervals.








April 1993 to August 1993
The last 273 of the 330 units were installed approximately two weeks prior to the completion of the as-built, August
1993 survey. The accretional and erosional areas can be illustrated by examining Figure 11, which shows the
elevation changes on a two-dimensional perspective. The wave energy during this period is indicative of summer
conditions. A result of this is the small irregular elevation changes that occurred across the study area. The most
notable feature is the gain of material in the nearshore zone accumulating within 75 feet of the shoreline over most
of the region. To the north of the study area, there are large fluctuations of elevation changes which may be due
to the interaction of the T-structures fronting the Breakers Hotel with that of localized profile adjustments.


August 1993 to December 1993
The completed 330 unit reef had been in place for approximately four months when the December 1993 survey was
taken. Figure 12 shows a gain of material in a region along the northern and southern portions of the reef. The
north region gained 1.5 feet of material along the 2,000 foot length of shoreline north of the reef. The gain of
material (up to 5.0 feet) within the northern 1,000 feet of the reef is in the area of the AT&T gap. A second area
behind the reef exhibiting accretion occurs along the southern portion of the reef in which up to +2.0 feet of
material had accumulated. In between these two areas, from the AT&T gap south to the end of the reef, the inner
region experienced large losses of material forming a depression, with the largest negative values toward the center











250
. 200
C 150
S100
g 50
0
s o
2 -50
C -100
-150
w -200
--250


'.:::--": /l I I \ lh~i V / I I -

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000
- North Distance from monument 92F (ft)


Figure 11 Isolines of Elevation Change (ft), April 1993 to August 1993. Contours in 0.5 foot intervals.








0 150



50 -
20-


100 5000 6000 7000 8000 9000 10000
M-150 :'. "

-200 ....
-250 -A "
0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000
North Distance from monument 92F (ft)



Figure 12 Isolines of Elevation Change (ft), August 1993 to December 1993. Contours in 1.0 foot
intervals.









of the reef. A lowering of the profile was observed during field work in December, where the bottom of the inside
wave gage had been exposed by more than a foot and a half as compared to the installed bottom depth of 0.5 feet
below the horizon of the sand. Large material fluctuations occurred in the north region of the study area as seen
during the past two periods. Additionally, most of the areas experience irregular elevation changes between -1.0
and +1.0 feet.


July 1992 to December 1993
The comparison of the pre-construction survey and most recent survey of December 1993 is a summation of the
elevation changes between each monitoring survey over the 17 month period. Examination of Figure 13 identifies
four areas of interest. The first is the gain of material that had formed seaward of the original 57 units between
the first two surveys which is still evident. Secondly, the landward region beginning just inside the reef and
extending south of the reef has experienced a continual accretion of material. The nearshore area gained up to 5.0
feet of material and the accumulation of material extends approximately 200 feet offshore. The third area of interest
is the seaward region south of the reef. Most of this area lost between 1.0 and 2.0 feet of material. Lastly, the
region landward of the reef underwent a net loss of material extending over the length of the reef. The bottom
adjusted by as much as -4.0 feet in some areas, with an average of approximately -2.0 feet over the area
experiencing erosion.


A'' B' C' D'-
250 :

200 /f).




0
44-
-150
100 o
50









0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000
Atl BI CccJD J
North Distance from monument 92F (ft)


Figure 13 lines of Elevation Change (ft), July 1992 to December 1993 Contours in 0.5 foot intervals.
-250
0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000

A -J B-NJ C 41J D --J
-North Distance from monument 92F (ft)


Figure 13 Isolines of Elevation Change (ft), July 1992 to December 1993. Contours in 0.5 foot intervals.










PROFILE CHANGES
The elevation changes can be summarized by four representative profiles indicated on Figure 13 as A-A', B-B',
C-C' and D-D'. Section A-A' (Figure 14) is located approximately 1,500 feet north of the north end of the reef.
This profile is representative of the changes occurring along this portion of the shoreline. The offshore area
between 350 and 600 feet have experienced a loss of material, while the dry beach had widened by approximately
25 feet. Section B-B' (Figure 15) is within the area of the reef, approximately the northern one-quarter point. The
profile starts at the seawall that fronts most of this shoreline. The inner region experienced a slight gain to the
landward end of the profile between April and August as illustrated for this period in the previous section.
However, the latest profile shows considerable erosion landward of the reef. Section C-C' (Figure 16) is the
southern most profile line that extends over the reef. This profile is in the vicinity of the public parking and
sidewalk that overlooks the existing dry beach. In the vicinity of the reef, material been lost both landward and
seaward of the reef since the pre-construction survey of July 1992. In the nearshore area there has been a continual
accretion resulting in a widening of the beach of approximately 50 feet. Section D-D' (Figure 17) is representative
of the profile lines south of the reef. Over the 17 months of monitoring, the offshore region has experienced a
small loss of material while the nearshore area and dry beach have gained substantially.


20

15

10

5

0

-5

-10

-15

-20


0 100 200 300 400 500 600
Distance from monument 94D (ft)


700 800
Seaward---


Figure 14 Profile North of Reef. Section A-A'. July 1992 to December 1993.



17


I I I I I I I
i*-Seawal :i
..................................... ....................................... L ................... .. S e c t ion.A.-.A *...
'p Section A A'
..... July 1992
.................. ....... ................... .................. ........... .......... -....... A p ril 19 9 3 .... .
.................---- April 1993
.-.-.- August 1993
.................. ................... ................................... D ecem b er 1993



S----------------


.. -............ ... .....-..-. ...N s.0., ,. ........ ......................-.
____ I I* I --i ---I -


,20














20

15

10

5

0

-5

-10

-15

-2n.


0 100 200 300 400 500 600 700 800

Distance from monument 96F (ft) Seaward---


Figure 15 Profile Approximately 1,000 Feet from North End of Reef. Section B-B'. July 1992 to
December 1993.


20

15

10

5

0

-5

-10

-15

-90


0 100 200 300 400 500 600 700 800

Distance from monument 99B (ft) Seaward---


Figure 16 Profile at Southern End of Reef. Section C-C'. July 1992 to December 1993.


I I I I I
i-
................... ..- -.... ............................. "" . S e c tio n B B.
Section B B'
S... July 1992
. ......................... ......... ....................................... ......................... o A p ril 19 9 3 ....
---- April 1993
S-.-.- August 1993
.......................... ..- ... ..... ................... .................. ......................... -- Decem ber 1993 /


Reef:

Seawall II

i.. . -. . .I- .


II I I I
- Seawall
................. ...........................................................................e c t io n C C '
I ..... July 1992
---- April 1993
S..................................... ............................ .................... ........... A p ri. 19 9 3
.-.-.- August 1993
.... December 1993 -

S.... ...- ................. .. .................................... .. ................ -- Decem ber 19 3 .

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



- o -


-20


f-w> \J













20 1 1 1 I I
Seawall
15 -- Section D D'
> J... July 1992
10 ..-- April 1993
Z .-.-- August 1993
5 -...... December 1993




S-10 -


-20
S-15 ......... ..........


0 100 200 300 400 500 600 700 800
Distance from monument 100B (ft) Seaward--



Figure 17 Profile Approximately 1,200 Feet South of Reef. Section D-D'. July 1992 to December 1993.



LONGSHORE SHORELINE CHANGE DISTRIBUTION
The changes in mean high water (MHW) shoreline positions are illustrated in Figure 18. The top graph shows the
changes that occurred between each monitoring survey and the bottom graph is the cumulative changes over the 17
months between the pre-construction and December 1993 surveys. The total shoreline change signals (Figure 18a)
along the northern 4,000 feet of the study area are mixed in nature, varying between negative and positive. Between
the 4,000 and 5,500 foot mark, the shoreline for the monitoring periods between July 1992 and April 1993, and
August 1993 and December 1993 experienced up to 45 feet of recession. As was seen in the two previous sections,
this same area for the April 1993 to August 1993 period experienced an addition to the dry beach width during the
summer conditions. The next segment of shoreline (between 5,500 and 6,500 feet) encountered very little shoreline
position change. The small fluctuations are predominantly due to the condition seen in Figure 15. This section
of the study area is fronted by a seawall and the profile is near or below the elevation of the MHW line thus
providing little potential for any change. The cumulative MHW changes (Figure 18b) reflect the trends occurring
in the top graph (Figure 18a). A mixed signal occurs to the north, negative change along the northern half of the
reef and a shoreline advancement from the centerline of the reef to the southern portion of the study area.




19















-! Reef
1 0 .. ..... .. ............. .... .


0 0





S...... July 1992 to April 1993
S--100 April Augs..t. .......................... April to August 1993
S-- August to December 1993

S-150 -
0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000
North Distance from monument 92F (ft)



Figure 18a Longshore Distribution of Mean High Water Shoreline Changes.




100 I

F4- Reef
S 5 o ....... .. ............... ............. .. ....... .. ............................. .... ..... .... ... ...........



0 --



S-100 r .. .....

July 1992 to December 1993
S-150 Max. shoreline recession
-- 1 0 0 ..... .................................................................... .. ...............ax...... se .


0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000
-*- North Distance from monument 92F (ft)


Figure 18b Longshore Distribution of Cumulative Mean High Water Changes and Maximum Potential
Shoreline Recession.









LONGSHORE VOLUME CHANGE DISTRIBUTION
This section presents the distribution of volume changes per linear foot (yds3/f) both landward and seaward of the
reef along the 9,800 feet of shoreline. This is based on the volume changes occurring for each of the profile lines
between monitoring surveys. Appendix III presents a tabulation of the volume changes for the inner (landward of
the reel) and outer (seaward of the reef) profile sections; those results are presented graphically in Figure 19. The
volume changes seaward of the reef (Figure 19a) vary between -25 yds3/lf and +20 yds3/lf across the length of
the study area. The most interesting signals occur at the 2,000, 4,000 and 7,000 foot locations. The northern signal
is mixed which may be due to the seawall and structures located in the vicinity of the Breakers Hotel. Except for
the second monitoring period, the signals located near the centerline of the reef reflects an accretional trend for this
seaward area. The signal at the south end of the reef are toward the erosional side, with the largest loss of material
occurring within 800 feet of the southern end.


Figure 19b represents the volume changes that have taken place during the monitoring period landward of the reef.
The signals north of the reef are somewhat mixed, but just inside the north end the region begins to experience loss
of material. This trend continues until approximately the 6,500 foot mark where accumulation occurs and continues
to the southerly limit of the surveys. These signals closely reflect the shoreline (MHW) changes presented in the
previous section. The second monitoring period (April to August 1993) is the least pronounced signal which may
be indicative of the summer condition that this period covers.


The volume changes per linear foot are converted into volume change (yds3) by the "average end method" which
are divided into regions landward and seaward of the reef. Each of the regions are approximately 240 feet in width.
The northern and southern regions extend 2,000 feet north and south of the reef and the central region is within the
longshore reef confines. The northern-most 2,000 feet is between monuments 94A and 95E, the 4,000 foot length
of the reef is between monuments 95E and 99A and the southern-most 2,000 feet is defined by monuments 99A and
101A (Figure 20). The survey data examined in the first three sections cover the time periods between the pre-
construction survey and the three subsequent monitoring surveys. The cumulative volume changes from the pre-
construction to the most recent survey taken in December, 1993 are presented in the last section. Refer to Appendix
II for the table of volume changes.

July 1992 to April 1993
The 57 units of the reef completed by the April survey were located between profile lines 98E and 98J, extending
approximately 680 foot length of shoreline. The shoreline landward of the reef (monument 98E to 99A) has
accumulated approximately 10,200 yds3 of material for an average gain of 17.0 yds3/lf across the profile to the reef.
For the region seaward of the reef (98E south to 99A) approximately 3,600 yds3 (5.9 yds3/lf average) had
accumulated along an equal shoreline distance.













50 1 i l i '
S...... July 1992 to April 1993
S 4 0 .............. i............... ............... I ............................... .. .... April 1993 to August 1993
44 40 .. April 1993 to August 1993
\ ----. August 1993 to December 1993
S 30 .... .......................July 1992 to December 1993
a 20
S 2 .. ........... .. ............ .................. .. ...... ... .. ........ -
1 0 --: -.- ..... ..





7 -30
-50

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000
-"- North Distance from monument 92F (ft)



Figure 19a Longshore Distribution of Volume Change (outer region) for Available Intersurvey Period and
for Total Period Available.



0- I I i i i i Reef
40 -

b2
10
..... ... ~- .. .-- *-**- -- ; -..... .... -.... ........ ......















S -10 -1 .. .. . ..



.S. ". ... .. I \ ....... July 1992 to April 1993
-30 --- ------ April 1993 to August 1993
O -40 ---- August 1993 to December 1993
> -40 -- ..........................- July 1992 to December 1993
-50 --ii -----1--------














0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000
*- North Distance from monument 92F (ft)


Figure 19b Longshore Distribution of Volume Change (inner region) for Available Intersurvey Period and
for Total Period Available.


22
22









The remainder of the analysis for this time period will examine the volume changes in each of the six regions as
described above. The northern portion of the reef had not been completed at the time of this survey, however by
extending the analysis to the north documents the conditions in this region for this time period. The completion of
the reef and subsequent surveys over the extent of the study will illustrate the effects of the reef which may become
more clearly interpreted with additional data. Figure 20 depicts the volume changes in each of the defined regions.
As documented in the first panel, the volume change in the north landward region was -13,600 yds3 (-6.8 yds3/lf
average). Landward of the incomplete reef footprint (including the 680 feet described above) has experienced an
erosion of -25,300 yds3 (-6.3 yds3/lf average) of material over the nine month time period. For the area south of
99A, approximately 23,400 yds3 (11.7 yds3/lf average) of material have accumulated within this landward region.


The seaward region between monuments 94A and 95E have experienced a cumulative volume change of -2,900 yds3
(Figure 20a) averaging -1.5 yds3/lf. The outer region that would be seaward of the completed 330 unit reef, has
had a negative change in the quantity of material by 5,200 yds3 in which the average of -1.3 yds/lf was a similar
value found adjacent to the north. The south seaward region shows a loss of -18,300 yds3 (-9.2 yds3/lf average)
of material.


April 1993 to August 1993
Between monuments 94A and 95E, the landward region north of the reef experienced a gain of approximately
+3,000 yds3 of material. Immediately south, within the limits of the reef, small fluctuations in the volume change
occurred, resulting in a total negative change of -150 yds3 (Figure 20b). A small gain (850 yds3) occurred in the
region from the reef extending 2,000 feet south to monument 101A.


The analysis of the north landward (+3,000 yds3) and the adjacent seaward region showed a similar gain in the
volume of material. Approximately +2,600 yds3 (+1.3 yds3/lf) of material had accumulated in this area (Figure
20b). The region seaward of the completed reef, lost approximately 1,200 yds3 between the April and August
surveys. During these four months, the changes that had occurred were not uniform across the study area, but
rather were isolated along the shore and across the profiles (Appendix II). The largest positive change for this time
period occurred in the south seaward region in which 4,300 yds3 (+2.2 yds3/lf) of material had deposited.


August 1993 to December 1993
The inner region between monuments 94A and 95E gained a total of 4,600 yds3 (2.3 yds3/lf) over the 2,000 foot
shoreline (Figure 20c). Most of this gain was confined to the nearshore area (Figure 12). South of this area within
the limits of the reef, 31,500 yds3 were eroded for an average of -7.9 yds3/lf. The only positive net change within
this area was located within the AT&T cable gap which experienced accretion of 4,500 yds3 between the two








July 1992 to April 1993


94A



95E




0
oz
98E
99A



101A


S240' +/--+- 240' +/---


-13,600 -2,900

I


-35,500 -8,800
I
I Reef
+10,200 +3,600

+23,400 -18,300


T
2000'





4000'





2000'

1


April 1993 to August 1993


+3,000 +2,600

'~~~~I """"Reef


94A



95E




z

99A



101A


-1,200





+4,300


240'+/-t- 240'+/-_


August 1993 to December 1993
94A

+4,600 -6,400 2000'

9 5 E ................................. e...... ............... -
95 l ---- R e ...--- f ........
95E I Reef


S-31,500 +1,300 4000'



9 9A ............................. .. ..................................

+16,700 -7,650 2000'

101A
240' +/--- 240' +/--+-


July 1992 to December 1993


94A



95E




0
z

99A



101A


-6,100





-57,000





+40,900


-6,700

IReef


-5,000





-21,700


S240' +/---- 240'+/---
(d)


Figure 20 Volumetric Changes in Various Zones for Available Intersurvey Periods and Overall Period.


-150





+850


7-v
2000'





4000'



-20
2000'

_V


2000'





4000'





2000'

1









surveys. In the southern 2,000 feet, there was an accumulation of 16,700 yds3 for an average +8.3 yds3/lf over
the length of shoreline.


The two outer regions north and south are experienced material losses of 6,400 yds3 and 7,650 yds3, respectively.
The average loss of material over the 2,000 foot shoreline has averaged -3.2 yds3/lf for the northern and -3.8 yds3/lf
for the southern region.


July 1992 to December 1993
The volume change table found in Appendix II and Figure 20d document the net changes that occurred during the
total 17 month period between July 1992 and December 1993. Five of the six regions have experienced erosion.
The volumetric erosion of the north inner region was 6,100 yds3 (+3.0 yds3/lf). Seaward of this region had a
similar erosion, -6,700 yds3 (-3.3 yds3/lf average). The sum of these two north regions totaled -12,800 yds3. The
largest erosion occurred landward of the reef. This region experienced an erosion of approximately -57,000 yds3
averaging -14.2 yds3/lf for the 4,000 foot shoreline. Erosion on the seaward side of the reef were smaller,
amounting to less than 10 percent of the erosion that occurred on the landward region, or 5,000 yds3. The total
between the two regions within the longshore confines of the reef -62,000 yds3. The only positive net volume
change of the six regions occurred within the south inner region. This area accreted 40,900 yds of material,
averaging +20.5 yds3/lf. This combined with the volume change in the seaward region of -21,700 yds3, resulted
in a positive net change of +19,200 yds3 for the southern portion of the project.


SEDIMENT ANALYSIS
Sand samples were collected along 19 survey lines at 6 to 8 positions across the profile. These samples were
collected immediately following installation of all 330 units. The sand samples were analyzed to determine their
mean grain diameter and the degree of sorting about that mean. The initial sampling will provide a baseline for
comparison to later sand sampling. The objective of the analysis is to determine the possible source of the sediment
in the vicinity of the reef. A typical analysis of one the samples taken is shown in Figure 21.


SETTLEMENT AND SCOUR CONSIDERATIONS


ELEVATION AND SETTLEMENT OF UNITS
Upon installation of the P.E.P. Reef units, settlement of each unit began. Post-storm surveys of the crest elevations
of each unit in combination with the quarterly surveys have established the settlement of the units over time. Figure
22 depicts the average settlement of the original 57 units and the remaining units that were installed in 1993. The
first 57 units were installed during the summer months of 1992, and have since experienced an average settlement
































10-1 100
grain size (mm)


Figure 21 Example of Grain
Reef.


Size Analysis for Sample in 9 Foot of Water Depth, Near North End of


4




3 ... .. ..... .. .. ........ .. .........
3-









1 i. .


/ Original 57 Units
-f/ Remaining Units

o i 0.I I I- I
0 2 4 6 8 10
t (months)


Figure 22 History of Average Settlement of Units Relative to Estimated Design Depth (original 57 units)
and Field Inspection Depth (remaining 273 units).


26


100


80 -..


60 --


40 k-


20 --..


10-2


~ -"~'' '''' II


D5o = 0.1
Dmoean = 0
... S.I. = 0.4
Skew= -
Kurtosis














1I 1111 I I


61 mm
.175 mm
87
0.253
= 0.834


12 14 16


I I I I 1II


I


0n









of 2.8 feet relative to the initial design elevation. The majority of this occurred during the first three months after
installation, and, as shown in the plot, the original 57 units appear to have reached an equilibrium position. The
design elevation was taken as the average of the values estimated in Coastal Tech (1993).


The remaining units were installed during the summer of 1993, and have settled an average of 1.4 feet relative to
their field inspection elevations. The individual survey elevations are plotted in Appendix IV for all 330 units. It
is noted that unit #315 represents the north end of the reef, while unit #330 represents the south end. This notation
remains consistent with the order of installation and the survey reporting procedures.


SCOUR ROD RESULTS
The twenty-eight scour rods were installed in July of 1993. The depth of the disks was measured and reinitialized
on two separate occasions. The first measurement occurred on August 14, 20 days after the initial measurement.
The second took place on December 15, 123 days from August 14th. According to the monitoring plan, the scour
rods disks are to be measured every 90 days, but due to adverse weather conditions, the time interval between the
first and second survey date was extended.


July 29, 1993 to August 14, 1993
Rods 1,2, and 3 are the control points for the south half of the study area and are located approximately 500 feet
south of the reef (Figure 4). The disks on the rods show a scour depth between 0.0 and 1.0 inches (Figure 23).
The largest change of disk position in the south half of the reef are found at the end at rods 4, 5, 6, 7, and 9, which
varied between 3.3 and 6.6 inches. Rods 10, 11, 12, and 13 are located at the center of the reef away from end
effects due to the opening in the reef or the terminal end of the structure. The scour was found to be less than 1.8
inches at this location.


The north control rods (26, 27, and 28) are located approximately 500 feet to the north of the reef. The change
in the scour disks range between 0.3 and 3.0 inches. Rods 14 through 19 are located at the gap in the reef for the
AT&T cable crossing. The disk elevation changes for rods 14 and 15, although small, were found to actually rise
by 1.0 and 0.5 inches, respectively. The rise in the disks may be due in part to an uncertainty in the underwater
measurement and tilt of the disk, estimated at 0.5 (+/-) inches. These two rods are located on the landward side
of the reef, adjacent to the AT&T opening. The remaining four rods in the AT&T gap have scoured between 0.5
and 2.2 inches. The north end of the reef is approximately 300 feet north of the AT&T gap. Of the six rods at
the north end, only the disk on rod number 22 had risen above its initial position (1.2 inches). The change in disk
elevation for the remaining rods (20, 21, 23, 24, and 25) vary between 0.3 and 3.0 inches.












0 ,- V *o -

S 5 ........ ........ ................... ........................ ....................
C.)1 v *



*.5 5 ....... ...... .- .... .. .............................................. ............. .......... .............
*a-i


V V
-20




2 5 .................................................................................................v ...... .........

7/29 to 8/14/93 (20 days)
-30 V 8/14 to 12/15/93 (123 days)


0 5 10 15 20 25 30
Scour rod number

Figure 23 Scour Rod Results for Two Periods.


August 14, 1993 to December 12, 1993
Of the 28 scour rods, only 17 were measured, as the disks at 11 rods were buried to depths making recovery
impossible. The depth of a twelfth disk was measured, but it was not possible to reinitialize it due to the rate of
sand transported back into the pit during attempted retrieval of the disk. New disks will be installed on those 11
rods where measurements did not occur or could not be reinitialized.


The disks on the three south control rods scoured between 10.3 and 14.5 inches. Only two of the disks at the
southern portion of the reef (8 and 9) could be compared to the control points. It was found that disks 8 and 9
scoured to a depth of 10.5 and 7.0 inches, respectively.


Only two of the three north control rods were measured (27 and 28), and had a elevation change of 18.8 and 16.2
inches, respectively. The ten scour rods in the northern portion of the reef exhibited scour between 11.3 and 30.0
inches. The highest scour occurred at the north end of the reef at rods 24 and 25. The disk on rod 24, which is
closest to the reef, scoured to 30.0 inches and the outer, rod 25, had a change in disk elevation of 25.3 inches. The
two rods just inside of the north end (20 and 21) experienced the second highest scour. The disk on the outer rod
(20) and the inner rod (21), were 24.0 and 22.5 inches, respectively. The remaining six rods exhibited disk scour
between 11.3 and 18.5 inches, that were in close proximity to the values found for the north control points.









INTERPRETATION & CONCLUSIONS


WAVE TRANSMISSION
Incident wave height and transmission over the reef was analyzed by a combination of spectral analysis, cumulative
frequency distribution of wave heights, and individual wave tracking.


For large waves, on the order of 3 feet in height, the wave height reduction is as much as 35%. The wave height
reduction has been shown to be greater during high wave events. Spectral analysis of the wave climate documents
reduction of the incoming wave energy, as seen previously in Figures 5 and 6. In each case the reduction appears
to nearly compensate for the effect of shoaling on the sloping beach, producing either equal or slightly lower
significant wave heights at the nearshore gage.


Transmission coefficients measured daily for significant wave height showed an average value of 0.75 over a three
month period. An average of 0.83 for October was measured, corresponding to smaller average significant wave
heights. November experienced several high wave events, and an average coefficient of 0.67 was measured. These
coefficients are compared to the pre-installation study by Lin (1986) in Figure 24. In this figure, R represents the
elevation of the top of the reef from the mean water level, h denotes the total water depth at the structure toe, and
k represents the non-dimensional wavelength. The measured data corresponds to a freeboard ratio (crest rise to
water depth at structure) of 0.58 on average. It is shown in the plot that the experimental values for the reef are
lower than those predicted by Lin (1986).


The transmission coefficient values reported are surprisingly low in light of comparison to published works.
Extraneous effects on the analysis are being sought and considered. One possible effect is the breaking of waves
between the reef and the nearshore gage, due to non-reef effects, i.e. smaller water depths at the nearshore gage
which naturally cause wave breaking. In addition, published works most often report laboratory measurements,
where reef induced breaking is avoided to isolate reef effects. This may be another source of difference in the
transmission values seen. To attempt to further validate the reef effects, independent measurements via video
camera and staff are being considered.


SEDIMENT CONSIDERATIONS
The interpretation of the effects of the offshore reef on the beach and nearshore system will become clearer with
the collection and analysis of more data. With only four months of data available for the completed reef installation,
and recognizing the "noisiness" of beaches, i.e. the natural variability, interpretation must be made cautiously.
However, it is possible to present some interpretations, some with more confidence than others.













0.9 \_\ +

++ +
+ + +


I + ++ +
+ + ++
0.7 + +

R/h = 0.57
0.6 ..... Rh = 0.44 -
-- Rh = 0.29
+ P.E.P. data


0.5 I I I
0.0 0.2 0.4 0.6 0.8 1.0
kh



Figure 24 Comparison of Measured Wave Transmission Coefficients with Those Obtained by Lin (1986)
from Wave Tank Tests.


Following the installation of the initial 57 units in August, 1992, there was a surprising amount of deposition in the
vicinity of and south of the reef, which was then about 680 feet in length. The odd/even analysis results are
consistent with sand trapping due to a combination of wave sheltering behind the reef and a circulation cell which
is landward over the reef and seaward near the two ends of the reef. However, this possible interpretation must
be tempered by the length of the depositional feature which extends more than 2000 feet south of the structure. This
characteristic suggests that the deposition is, at least in part, a natural occurring event.


The overall volume changes in the vicinity of the reef have been presented in Figure 20. These results can be
presented as functions of time as shown in Figures 25 and 26 for the areas landward and seaward of the reef,
respectively. Referring to Figure 25, it is seen that landward of the reef and within the reef confines, there has
been a continual decrease in volume and that the rate of erosion has increased over the latest intersurvey period after
full installation of the reef. For the 2000 feet segments north and south of the reef, there has been a continual
increase in volume. The net volume change within this 8000 feet region has been one of continual erosion.
Referring to Figure 26 which presents the same type of information for the region seaward of the reef alignment,
it is seen that there is a consistent erosional trend for the areas immediately adjacent to the reef and north and south
of the reef. A preliminary working hypothesis for the volume changes is presented below.









The working hypothesis which is consistent with observations of volume changes and knowledge of wave mechanics
and sediment transport processes is presented as follows. Water is conveyed over the reef by wave mass transport,
a well accepted and understood phenomenon. Due to the presence of the reef in the lower portions of the water
column,, the return of the water to the offshore as would normally occur is impeded and a portion flows alongshore.
The volume and velocity of the alongshore flow increases with distance and as a result transports sediment both
north and south. Upon reaching the ends of the reef system, the water flowing alongshore is no longer confined
and spreads out and deposits the sand that was being transported from landward of the reef. At the locations of
deposition, the beach profiles have an excess of sand and onshore transport occurs, causing the beaches to widen.


Additional monitoring results will enable evaluation, and as appropriate, modification of the interpretations offered
herein.


In conclusion, data for the completed reef system are only available for a six month period. Also complicating the
sedimentation interpretation are the following: (1) Possible seasonal effects, (2) The termination, approximately 3.5
years ago, of the sand transfer plant operations at Port of Palm Beach Entrance, located approximately 4.5 miles
to the north (updrift), and (3) Removal of the groins in the Mid-town Beach area in 1986.














SURVEY DATES


First 57 Units
Installed


I U"

O^" 0
>




<
- 50000


- 50,000


Remaining 273
Units Installed
i<->


240' 240'

24000'


2000'


(b) 2000' N and S of Reef


TIME


Reef Confines


Figure 25 Cumulative Volume Changes Landward of Reef Alignment. (a) Within Reef Confines, and (b)
Within 2,000 Feet North and South of Reef.












CM
0)

3


First 57 Units
Installed

+ 50,000-


z
LUJ




0
13



W
-.

S -0

>
-J



0


SURVEY DATES


Remaining 273
Units Installed
I N 1


240' 240'
1<- >1< ->


$2000'

14000'


000'


I ; :TIME
20 (months)
(a) within Reef Confines


N and S of Reef


50,000







Figure 26 Cumulative Volume Changes 240 Feet Seaward of Reef Alignment. (a) Within Reef Confines,
and (b) Within 2,000 Feet North and South of Reef.









surveys. In the southern 2,000 feet, there was an accumulation of 16,700 yds3 for an average +8.3 yds3/lf over
the length of shoreline.


The two outer regions north and south are experienced material losses of 6,400 yds3 and 7,650 yds3, respectively.
The average loss of material over the 2,000 foot shoreline has averaged -3.2 yds3/lf for the northern and -3.8 yds3/lf
for the southern region.


July 1992 to December 1993
The volume change table found in Appendix II and Figure 20d document the net changes that occurred during the
total 17 month period between July 1992 and December 1993. Five of the six regions have experienced erosion.
The volumetric erosion of the north inner region was 6,100 yds3 (+3.0 yds3/lf). Seaward of this region had a
similar erosion, -6,700 yds3 (-3.3 yds3/lf average). The sum of these two north regions totaled -12,800 yds3. The
largest erosion occurred landward of the reef. This region experienced an erosion of approximately -57,000 yds3
averaging -14.2 yds3/lf for the 4,000 foot shoreline. Erosion on the seaward side of the reef were smaller,
amounting to less than 10 percent of the erosion that occurred on the landward region, or 5,000 yds3. The total
between the two regions within the longshore confines of the reef -62,000 yds3. The only positive net volume
change of the six regions occurred within the south inner region. This area accreted 40,900 yds of material,
averaging +20.5 yds3/lf. This combined with the volume change in the seaward region of -21,700 yds3, resulted
in a positive net change of +19,200 yds3 for the southern portion of the project.


SEDIMENT ANALYSIS
Sand samples were collected along 19 survey lines at 6 to 8 positions across the profile. These samples were
collected immediately following installation of all 330 units. The sand samples were analyzed to determine their
mean grain diameter and the degree of sorting about that mean. The initial sampling will provide a baseline for
comparison to later sand sampling. The objective of the analysis is to determine the possible source of the sediment
in the vicinity of the reef. A typical analysis of one the samples taken is shown in Figure 21.


SETTLEMENT AND SCOUR CONSIDERATIONS


ELEVATION AND SETTLEMENT OF UNITS
Upon installation of the P.E.P. Reef units, settlement of each unit began. Post-storm surveys of the crest elevations
of each unit in combination with the quarterly surveys have established the settlement of the units over time. Figure
22 depicts the average settlement of the original 57 units and the remaining units that were installed in 1993. The
first 57 units were installed during the summer months of 1992, and have since experienced an average settlement










REFERENCES


Berek, E.P., and Dean, R.G., "Field Investigation of Longshore Transport Distribution," Proceedings of the
Eighteenth Coastal Engineering Conference, pp. 1620-1639, 1982.

Coastal & Oceanographic Engineering Department, "Florida Coastal Data Network, Wave and Current Data
Summary," University of Florida, 1993.

Coastal Technology, "Eight-Month Follow Up Report, Experimental P.E.P. Reef Project," Coastal Technology
Corporation, May, 1993.

Dean, J.L., and Pope, J., "The Redington Shores Breakwater Project: Initial Response," Coastal Sediments '87,
pp. 1369-1384, 1987.

Lin, N.K., "Final Research Report: On the Performance of Prefabricated Erosion Protection Reefs for Beach
Erosion Control," Florida Atlantic University, 1986.

Work, P.A., and Dean, R.G., "Shoreline Changes Adjacent to Florida's East Coast Tidal Inlets," UF/COEL
90/018, 1990.











APPENDIX I



P.E.P. Reef

Offshore & Nearshore

Wave Gage Data


(Consistent with FCDN, units are given in meters. 1 m = 3.28 ft)











1.5



1.0



0.5



0.0


date


Figure I-1 Offshore Gage Significant Wave Height, September 1993.


date


Figure I-2 Offshore Gage Modal Period, September 1993.


date


Figure I-3 Offshore Gage Modal Wave Direction, September 1993.
I-2


-~
-4+ 4+
++++
S+ + -t +
+ + 4 ++ +
+ ++ +- ++ +



_ _. . . . I . .I I. .I .


+
+ +++ + + +
+ +++ +

+ + +++++ + +


H + + + ++
++ .


++- +
++ +. ++ +t 4+ + + + +++
-i + i- ++++++ +++ +44- + +
+ +- +I+,+ +I++-+ 1 4 I










0.5

0.4

0.3


0.0'-1 -
0 5 10 15
date

Figure I-4 Offshore Gage Mean Current, September 1993.


N


W


CP S


E


N


20 25 30 35


date

Figure I-5 Offshore Gage Mean Current Direction, September 1993.


1.5



1.C



0.5



n


0
0


date


Figure I-6 Offshore Gage Significant Wave Height, October 1993.
I-3


+ + --- + + '
++
+ + +

+

+ +

+
+ +++



+
+- ..4. . . 4, -+4- ft++ f4-F 4,


)

+
4+ + + + +
-+ 4+ + +++ 44 4
+t + -+ ++

++ + *
++ t+ ++ + +* +* +
V + -+
^ % -

, --- I-,- i,-- ,-I --- -- ^ -1----- i I-, --- 1 I- r,- i,-- I -- ^ ---














S 10 -+ -H- + ++ f +- + -H-++ +-
+ + 4+H+ + ++ +++H---
S _. H+ ++ + + 4H -4-
+ + +
+ + +
5 + + +
+ + -H-4+ +


0 5 10 15 20 25 30 31
date

Figure I-7 Offshore Gage Modal Period, October 1993.


5 10 15 20 25 30 35
date


Figure I-8 Offshore Gage Modal Wave Direction, October 1993.


0.5 .

0.4

0.3 + +
+ +

0.2 ++ ++
+ + ++ + +
0.1- + +- + ++- + ++- + -
+ + + ++ + +
0 .0 + 4. +


date

Figure 1-9 Offshore Gage Mean Current, October 1993.
1-4















w


o
p S


E


N


date

Figure 1-10 Offshore Gage Mean Current Direction, October 1993.


1.5



1.0




0.5



0.0


date


Figure I-11 Nearshore Gage Significant Wave Height, October 1993.


Figure 1-12 Nearshore Gage Modal Period,


date


October 1993.
I-5


+---- T --- + +- i -f- V + q t+ -- --- I --
++ + + + +

+ + 4
+ +
S+ + +
+4+k + 4 + + +
+ +
+ +
+ 4


++ +
. . +


-I

+ ++
-4-
S+ + + +
S + 4 + + +

+++


+
-++ ++ ++
-+F +1+ ++ + ++-+ +
4 \i + H +


+ + !


\ 4 + 4
























date


Figure 1-13 Nearshore Gage Modal Wave Direction, October 1993.


0.5

0.4

0.3

0.2

0.1

0.0


5 10 15 20 25 30 35
date


Figure 1-14 Nearshore Gage Mean Current, October


N


W


cp S


E


N


date


Figure I-15 Nearshore Gage Mean Current Direction, October 1993.


+ + +
,+ -H- + +++ + +




. . . . .iiil


S+++' ++ +" 'f+

+ 4 +
+
+ ++ ++ + + 4
, + + + +++-++
+ +

__+S + --









1.5

+ +

S1.0 + + + + +
S++ +4
++ ++ +H + + ++
S+ + '+ +++ + + +++
++ + +++ + + +
0.5 ++ + + + + +
+ + 4


0 5 10 15 20 25 30 3
date

Figure 1-16 Offshore Gage Significant Wave Height, November 1993.


5 10 15 20 25 30 35
date


Figure 1-17 Offshore Gage Modal Period, November 1993.


date


Figure 1-18 Offshore Gage Modal Wave Direction, November 1993.


+

S+4 ++ ++ + Hr-+++-+++t -+ +
+ + ++++++ ++ ++++++++++ ++F +++ + +++ ,+










0.5

0.4

3 0.3

0.2-
++ + + + + 4
+++ -4 ++ -+ + 4- + + 4+ +--
0.0 + + +t + + -,- +
0 5 10 15 20 25 30 3
date

Figure 1-19 Offshore Gage Mean Current, November 1993.


N


W


o S


E


N


date


Figure 1-20 Offshore Gage Mean Current Direction, November 1993.


1.5



1.0 ++
++ +

0+ + + +4 + +
0.5 +++ +
0.5 + ++ + +
+ +++ 4 +
0+ 0
0.01--"^--


date


Figure 1-21 Nearshore Gage Significant Wave Height, November 1993.
I-8


- -1-------^ -----
+ +

+
+
S+4


+ +










15
15 .--.--.--.--.--.--.--.-.--.--.--.--.--.--.--.-.--.--.--.

++4 +
+ ++ ++ + +
o1 0 + ++ + +H+ +1 + ti + ++ +
S + + +-H- + H+ ++
+ + + + ++ +
1 + + ++ ++
++ +
5 + + ,1+ 4-
+



0 5 10 15 20 25 30 3!
date

Figure 1-22 Nearshore Gage Modal Period, November 1993.

N
N . . . . . . . .


W -+ ++ +f^- -F4-+ +4+4 + .-H4
+ + i +, + ** v+4+ **, -i

d s


E


N


date


Figure 1-23 Nearshore Gage Modal Wave Direction, November 1993.


0.

0.

0.

0.


n


0


date


Figure 1-24 Nearshore Gage Mean Current, November 1993.


5

4

3

2
2 + +
4 + + +

+ ++ + +
r











N


W


q S


E


N


date


Figure 1-25 Nearshore Gage Mean Current Direction, November 1993.


0.0


date


Figure 1-26 Offshore Gage Significant Wave Height, December 1993.


date


Figure 1-27 Offshore Gage Modal Period, December 1993.
1-10


++




+ ++++ ++ ++ +

++
+ + + + ,
+ +

+ + -1


+ + +
S++ ++ + ++
+ + + +
+ ++ + + + ++-
+ + -+ + +
S++ + ++ + +

_+i i + 4 I i I + 4+ + t
+^ +++
4 .I ..- I.1-I I


4 +t--+ 4++4H- 4
+ -t-
+ +

++ + ++++ + +tf + +1 + + +
-1- + +
4 ++44 444 + 4 ++4+ 41
S+ 4 + + +


+ + + + +

























date

Figure 1-28 Offshore Gage Modal Wave Direction, December 1993.


0.5

0.4

0.3

0.2

0.1

0.0


date


Figure 1-29 Offshore Gage Mean Current, December 1993.


N


W


S S


E


N


date


Figure 1-30 Offshore Gage Mean Current Direction, December 1993.
I-11


+ 44- +

++++ + 4+ + + +
+- + ,--i+ # i+ ++


++ -
-t-

4+- -
+ +
+ + + + ++ F ++ + +4+44++ ++
+ + + + 4+++ +
+ + ++-+ ++ + +, ++ + +
4, + --++ ++-, 4+ .


+' ,+ '+- ,+' + %+<-l-




+ + ++
+* + ++ + ++
+ +

4A +4 + 4F i4++ 4+
4+ _F + + -+ + +

S4+ +
+ +










1.5



1.0



0.5



0.0


date

Figure 1-31 Nearshore Gage Significant Wave Gage, December 1993.


date


Figure 1-32 Nearshore Gage Modal Period, December 1993.


date


Figure 1-33 Nearshore Gage Modal Wave Direction, December 1993.
1-12


++

+
+ + ++++ + +
+ + + 4 +

t+ + + ++ + +
+4 4 + + ++ +

+ + +


+ + -- + +

4
+ -H +- + + + +t-
+ + S t+ 4+ + + +4
+ + ++ + + + ++ + 4+ 4+

+
4 4

i i i i i i i l i i i I I i i i I i i r i i i


+
+ t "1-t tm- t+i+t










0.5

0.4

0.3

0.2

0.1

0.0


date

Figure 1-34 Nearshore Gage Mean Current, September 1993.


CP S


date


Figure 1-35 Nearshore Gage Mean Current Direction, December 1993.


1-13


+
+

++ +++ + + +
+ + + + + .++ + ++ + +- 4
.4 ^^ 4 t,+-i4 ++ + ++ +


+ +x +++ + +++ -+ +
+ + + + + +
+ '+ 4
S- + +
+ + + ++
+ ++ + 4+












APPENDIX I


Even/odd Analysis










EVEN/ODD ANALYSIS


INTRODUCTION
Volumetric changes within the study area were analyzed using the even/odd analysis technique as presented in Berek
and Dean (1982) and Work and Dean (1990). The net shoreline volume change along the study area can be divided
into even and odd functions. An even function is symmetric about the y-axis such as the cosine function, and
represents a net volume change. Integrating the even function results in the net accretion or erosion that has
occurred within the study area during a given time period. The odd function is anti-symmetric about the y-axis,
for example, a sine function, and could represent the change due to interruption of longshore sediment transport.
The odd function integrates to zero. The end effects of a structure in the nearshore may show a positive volume
change on the updrift side of the structure and a negative volume change in the downdrift direction (Dean and Pope,
1987). If the signal is locally inverted, such as what would be evident at the end of a seawall or downdrift side of
an inlet, this could indicate reversals in sediment transport immediately adjacent to the structure causing a small area
effected by updrift erosion. Even functions, yE(x), can be expressed mathematically as follows:

y(x) +y(-x (1)


and the odd function, yo(x):

yo() =Y (x)-y7(-x) (2)
2

Note that YT( ) is the net volume change at x and -x coordinates. The derivation of these functions are found in
Work and Dean (1990). These previous studies examined shoreline changes of the MHW line. For this study, the
methodology is extended to profile volume changes.


METHODOLOGY
The analysis used the pre-construction profiles taken in July, 1992 as the baseline condition and three subsequent
beach and offshore hydrographic surveys. The profiles extend a minimum of 1,200 feet offshore and 9,800 feet
along the shoreline. Stationing begins at monument 92F (STA 0+00) and increases to the south. The center of
the reef is approximately at STA 52+50. The first monitoring survey was completed in April, 1993, at which time
the first 57 units had been installed along the southern portion of the reef footprint. The units had been in place
for approximately nine months when the survey was completed. The post-construction (second) survey was
completed in August, 1993, approximately two weeks after the installation of the last of the 330 units. More
recently, the third and last monitoring survey currently available was completed mid-December 1993. The pre-
construction (July, 1992) profiles were compared to the profiles from the three subsequent surveys to determine the
net volume changes since the installation of the units. The computer program ISRP-VOLUME21 of the U.S. Army


































Figure I-1 Cells for Volume Change Computation


Corps of Engineers, calculated the cut/fill volume changes in incremental cells along each profile line (Figure I-1).
The cells are divided into equal distances from the upland dry beach or seawall, seaward to the submerged reef
(identified as the inner volume) and to an equal distance seaward from the reef (outer volume). The cells are 60
feet in width but vary depending on the distance of the reef from the seawall.


The volume change (cubic yards per linear foot of shoreline) versus distance from a point of interest on the reef
was divided into even and odd functions by the use of a computer program. The first comparison (July 1992 to
April 1993) considers the center-line of the initial 57 units as the y-axis. Due to the relatively short length of the
structure, the signature of the functions are not substantially modified by varying the location of the y-axis along
the structure. Therefore only the one location is analyzed. For July 1992 to August 1993, and the July 1992 to
December 1993 comparisons, the origins are considered at three stations on the completed reef; north end, center
and south end, to develop the even and odd functions. The even/odd analysis compares each of the monitoring
surveys to the pre-construction survey of July 1992. The reason for this is the small changes that had occurred
between the April 1993 and August 1993 surveys. The weak signals resulting from this analysis can be considered
as "noise" and may not be significant. The one-year report will make a more detailed comparison between each
of the succeeding surveys and with the additional data a correlation may result. Calculation of the net change, and
the even and odd functions are displayed graphically in Figures I-2 to II-8. The x-axis indicates the distance (feet)
from the y-axis location on the reef. Negative and positive values are north and south of the y-axis, respectively.










The y-axis is volume changes (cubic yards per linear foot of shoreline, yds3/lf) with positive and negative values
indicating accretion and erosion, respectively.


JULY 1992 to APRIL 1993
Origin at Reef Centerline
The y-axis is located at the center of the 57 unit reef at STA 69+50. The ends of the reef are located at
approximately -400 and +400 feet. The net volume change of the outer cells exhibit two accretional peaks (upper
panel of Figure 1-2). The first is north (-2,000 feet) of the y-axis and the second is located at the origin. The two
peaks indicate a maximum gain of 12 to 14 yds3/lf of shoreline. The most pronounced erosion occurs from +400
to +1,200 feet. The outer cells are accumulating material in the vicinity of the reef. As water is transported over
the structure secondary currents may be produced, resulting in material being transported from the landward ends
of the reef to the seaward side of the structure. The net change is reinforced by a positive even function that is
equal in magnitude. Erosion of material occurs from the outer cells immediately to the south of the reef, where
even and odd functions are similar in form, but only half the magnitude of the net volume change. The signal
adjacent to the reef may be in response to end effects of the structure causing local sediment transport reversals,
resulting in a negative volume change. Further south, the large negative volume change (-23 yds3/lf) may be due
to the downdrift effects of groins. The remaining length of shoreline tends on the erosional side, with most
fluctuating between 0 and -10 yds3/lf, and may be "noise", i.e. natural variability.


The signature of the inner cells (lower panel of Figure 1-2) shows a clearer trend than the outer cells. The largest
gain tends to be found between -300 and +500 feet of the y-axis, although significant increase occur to the full
southerly limit of the survey. The even component is consistent with volumetric trapping landward of the units and
the odd component is consistent with at least partial interruption of longshore transport.


JULY 1992 to AUGUST 1993
Origin at North End of Reef
This north section of the reef had only been in place for approximately one month when the second survey was
completed. The y-axis is located at the north end of the reef at STA 32+00. The outer cells at the north end of
the reef do not exhibit a distinct signature of the net change or either to the even and odd functions (upper panel
of Figure 11-3). Volumetric changes are of small fluctuations, with values ranging between -10 to 10 yds3/lf. This
indistinctive signature can be considered "noise".


The net volume change for the inner cells is predominately negative, that is reflected in the even function with an
average value of -10 yds3/lf (upper panel of Figure II-3). The area immediately south of the north end from 0 to
approximately +600 feet, is the location of a semi-exposed pocket beach at Clarke Avenue. This area shows a










greater loss of material, which is reflected in the signals of net change, odd, and even functions.


Origin at Center of Reef
The location of the y-axis is approximately at the center-line of the reef at STA 52+50. The north and south ends
of the reef are located at -2,000 and +2,000 feet, respectively. There are two areas within the outer cells (upper
panel of Figure I-4) at the south end of the reef which displays a volumetric change characteristic of end effects
of a structure. Along the length of the initial 57 units, there is an accretion of material that matches the odd
function signature. The accumulation of material may be interpreted as the result of longshore transport. This
tendency of the net change and odd component reflecting each other is seen on either side of the positive signal,
but with a negative value. The negative volume change at the south end of the reef may be interpreted as the result
of two mechanisms. First the material from the downdrift side is transported north accumulating seaward of the
structure, and secondly the material may be transported around the end of the reef and deposited landward of the
structure. Refraction of waves around the ends of the reef may transport material towards the center of the reef,
causing a negative volume change to the adjacent nearshore area. The even function of the outer cells do not have
a strong signal indicating that the cross-shore movement of material may not be a dominant process.


The lower panel of Figure H-4 shows the negative net volume changes on the north portion of the study area for
the inner cells with the accretion of material increasing to the south. The odd component also follows this positive
trend in the longshore accumulation of material. There are two strong signals near the two ends of the reef (-2,000
and +2,000 feet). A large volume of material has accumulated at the south end of the reef, which is the location


of the earliest reef installation. It may be by coincidence that there is a negative signal of the odd function that
closely reflects that of the net volume change located at the north end. This area has experienced a negative volume
change from the pocket beach located at the -2,000 foot mark. Also, the calculation of the odd function would
result in such a shape and magnitude from two equal, yet inverse net changes. The signals with similar form of
width and magnitude in both the net change and odd function suggests a strong connection to each other. The even
component has a small (approximately -3 yds3/lf by observation) negative average reflecting the loss of sediment
within the study area. It also may indicate that the cross-shore transport is not significant.


Origin at South End of Reef
The extreme south end of the completed reef is located at STA 73+00. The y-axis is centered at this location of
the reef with the limits of this analysis at -2,500 and +2,500 feet. The signatures of the outer reef (upper panel
of Figure H-5) for the south y-axis location suggest processes occurring along this portion of the shoreline. The
net change and the odd component closely reflect the shape and magnitude to one another. Accumulation of material
within this area of the reef, coupled with the negative volume change that occurred adjacent to the downdrift side









of the reef is characteristic of the shoreline responses to structures. By observation, the positive volume change
to the updrift side is approximately equal to that of the downdrift negative volume change.
The lower panel of Figure I-5 indicates a volumetric increase from north to south for the inner cells. Along the
location of the original 57 units of the reef, there is a large positive signal in the net volume change with a
maximum of approximately +22 yds3/lf. The odd function reflects the trend in the increase of volumetric change.
However, there is a localized negative signal south of the south end of the reef. This negative value may indicate
that the material is being transported towards the reef by wave refraction. If the reef did not have an effect, then
the net volume change between 0 and +1000 feet may have been stronger. The even function is positive with the
accretion in the inner cells a result of cross-shore transport with a component of the material possibly being
transported from the outer cells which are losing material.


JULY :1992 to DECEMBER 1993
Origin at North End of Reef
The December 1993 survey is the second monitoring survey completed since the installation of the final unit of the
330 unit reef which occurred approximately 5 months prior to this work. The y-axis is located on the northern most
end of the reef at STA 32+00. The net volumetric changes in the outer cells (upper panel of Figure 1-6) vary
between -14 and + 12 yds3/lf of shoreline, with the negative and positive peaks occurring at 0 and +1,800 feet,
respectively. The erosion of material at the y-axis is not isolated at the end, but extends both north and south along
the reef from this location. Although the signal is not strong, the integration of the even function is negative
indicating an erosional tendency in the study area. Due to small signal fluctuations, the odd function does not
provide any relevant information.


The signatures of the inner cells are much more revealing as to the processes occurring in the northern portion of
the study area. As seen in the signature of the previous monitoring interval (July 1992 to April 1993), the net
volume change landward of the reef exhibits strong erosional values. In fact, except for one area, the magnitude
of the negative changes has almost doubled.


Origin at Centerline of Reef
The outer cells (upper panel Figure 1-7) show a similar form as compared to the July 1992 to August 1993
monitoring period, but with slightly higher volume change magnitudes. The south end of the reef illustrates the end
effects that structures may have on the adjacent shoreline. The south side of the reef has a large negative value of
approximately -21 yds3/lf. Just to the updrift side, there is a positive (+18 yds3/lf) volume change. The remainder
of the signal varies between + 10 and -10 yds3/lf, and may be "noise".


The inner cells (lower panel of Figure 1-7) show an increase in the accumulation of material along the southern










portion of the reef. The previous monitoring interval had an average positive value of approximately + 12 yds3/lf
from +600 to +4,500 which then increased to an average of +20 yds3/lf over the same length of shoreline for the
July 1992 to December 1993 analysis. The magnitudes of the negative volume changes have also doubled. This
is seen between the north end of the reef and +800 feet. This negative signal correlates with that of the even
function, when integrated over the study area, yields a large negative net volume. The odd function south of the
center-line of the reef is increasingly positive to the south. There is a strong negative and positive signal component
at -1,900 and +1,900 feet, respectively. This is the result of the positive net change at the southern end of the reef
and negative change at the north end of the reef, located at the pocket beach at Clarke Avenue. The net change
and signature of the odd function was similar in the previous time interval (July 1992 to December 1993).


Origin at South End of Reef
The results with the y-axis located at the southern end of the reef closely reflect the signals from the previous time
interval (July 1992 to August 1993) for the outer cells (upper panel of Figure H-8). South of the reef, the outer
cells exhibit an erosion of 20 yds3/lf extending from the end of the reef to approximately +700 feet, an average
decrease of 10 yds3/lf compared to the July 1992 to August 1993 analysis. The updrift side of the south end has
a positive, but smaller volume change. The even function has a slight negative volume change extending across
the study area indicating that material is being removed. The odd function provides some information as to the
longshore transport of material in the outer cells. The longshore trend seems to be consistent with that seen and
discussed previously. Material seaward of the reef is transported from the downdrift side of the structure to the
updrift seaward side of the reef. However, the area of the net accretion adjacent to the reef is smaller than the
downdrift side, which may indicate that material from the outer cells is deposited landward of the reef.


The inner cells show an increasingly positive trend from north to south within the study area (lower panel of Figure
H-8). The minimum net volume change is -34 yds3/lf at -2,300 feet, increasing to +25 yds/lf at approximately
the y-axis. At this point and to the south, the volume change decreases slightly to an average of approximately + 15
yds3/lf, then drops to a small negative volume change at +2,500 feet. The average volume change is approximately
5 yds3/lf greater than seen from July 1992 to August 1993. The even function has a strong positive signal between -
1,000 and +1,000 feet. This has increased by an average of +8 yds3/lf along the same length of shoreline from
the previous analysis. The negative signal of the odd function adjacent to the end of the reef, although small,
exhibit local higher longshore transport. This may indicate that the end effects of the reef are still present but may
not be as pronounced as previously seen.






40


30 -

20-

b 10 ...




9 -20 --------
o


S-30O ----
0-10

|-20 -
o
S-30 -

-40
-3000



40

30 -

S20--

S10
a)
o-


> -20 --.

> -30 -------


-40'
-3000


-2000 -1000 0 1000 2000 3000
Distance from y-axis (ft)


-2000 -1000 0 1000 2000 3000
Distance from y-axis (ft)


Figure H-2 Even/odd analysis of volume change, outer cells (upper) and inner cells
located at center reef (STA 69+50), July 1992 to April 1993.


(lower), y-axis







40
3 0 ) --- N et ..........--------------------I-------------------------------
30 Net
---- Even
.. .- Odd


0



S-- -... .. ...... .... ....... ..............
0 A\



-0 Reef
> 3 0 ...... ............... ............ ........................ .............. .............................................

-40
-4000 -3000 -2000 -1000 0 1000 2000 3000 4000

Distance from y-axis (ft)

40

3 0 ..... ........ .............. .N e......
---- Even Reef -
2 .-.- Odd



? -10 ------ ---- --- -- -- -




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

10 ....0 .......I-------/----A-----r-------- -------- ------- ---------







40
-40 -----------............... .............. : .............................................................

-4000 -3000 -2000 -1000 0 1000 2000 3000 4000

Distance from y-axis (ft)

Figure 1-3 Even/odd analysis of volume change, outer cells (upper) and inner cells (lower), y-axis
located at the north end of reef (STA 32+00), July 1992 to August 1993.






40


30

I20
-SO
S 10 .......


0 -10

o
'S-10---
1-20---

-30 --

-40
-6000



40

30 -

20--

S10 -

0



-20 -
> -30 -


-4000 -2000 0 2000 4000 6000
Distance from y-axis (ft)


-40' I I
-6000 -4000 -2000 0 2000 4000 6000
Distance from y-axis (ft)

Figure 1-4 Even/odd analysis of volume change, outer cells (upper) and inner cells (lower), y-axis
located at center reef (STA 52+50), July 1992 to August 1993.


II-10







40
^U--

30 -

< 20--
20-
2 0 -----

0 -10 -

o

S-30 ----

-40-
-3000


40

30

20

10



0-10

9-20
o
> -30


-40'
-3000


-2000 -1000 0 1000 2000 3000
Distance from y-axis (ft)


-2000 -1000 0 1000 2000 3000
Distance from y-axis (ft)


Figure II-5 Even/odd analysis of volume change, outer cells (upper) and inner cells
located at south end of reef (STA 73+00), July 1992 to August 1993.


(lower), y-axis


H-11







40

30 et... ...... ... .... .... ................... I ----------- ---N........ ._.
---- Even
2 0 dd ....... ........... ......................... .......... .... ........... ... ...............

,- ., d.. .. d-. "-. .,, .
0





-4000 -3000-2000-1000 0 1000 2000 3000 4000


20 ----- -R---- ---------I'll----------------
,., ------------- ............ I ............ ,, ............. .............. .......... ....... ....... ...... -.-------



Distance from y-axis (ft)

40

30 :

S10 ---- --- -- -............................................ .. .----- ............... --.--. ------
Reef ,
2 0 ...... .................. . . . ...... ..........................


30............... ................. ........... ..
1 0 ,1 \ ,

0




0 ... Even
--30 Odd

-40
-4000 -3000 -2000 -1000 0 1000 2000 3000 4000
Distance from y-axis (ft)

Figure II-6 Even/odd analysis of volume change, outer cells (upper) and inner cells (lower), y-axis
located at north end of reef (STA 32+00), July 1992 to December 1993.


II-12








30 -

020

^ 10 ........

0
-20-
0 -10 -..


-30 ---
30 ........

-40
-6000


40

30

20

zb 10

(0


S-to
9-20

>-30


-40
-6000


-4000 -2000 0 2000 4000 6000
Distance from y-axis (ft)


-4000 -2000 0 2000 4000 6000
Distance from y-axis (ft)


Figure I-7 Even/odd analysis of volume change, outer cells (upper) and inner cells (lower), y-axis
located at center reef (STA 52+50), July 1992 to December 1993.


1-13






40

30 -

i20--





- 2 0 --------


> -30 o

-40
-3000


40

30

20

S10
0

0-10

|-20
-30
-30


-40L
-3000


-2000 -1000 0 1000 2000 3000
Distance from y-axis (ft)


-2000 -1000 0 1000 2000 3000
Distance from y-axis (ft)


Figure I-8 Even/odd analysis of volume change, outer cells (upper) and inner cells (lower), y-axis
located at south end of reef (STA 73+00), July 1992 to December 1993.


I-14









APPENDIX III


Tabulation of Volume Change













P.E.P. Reef Monitoring Volumetric changes between survey lines dated July 1992 and April 1993.

SDistance b/ Distance to Lenght of Volume Change (cu. yards/linear foot) Inner Volume Inner Cumul. Outer Volume Outer Cumul. I Total Cumul.
Profile Une Unes (t) I Reef (ft) Cella (ft) 1t Cell 2nd Cell 3rd Cell 4th Cell 5th Cell 6th Cell 7th Cell 8th Cell Total Change(cu.yds Change (cu.yd) Change (cu.yds) Change (cu.yd) I Change (cu.yd)


92F
400
938
200
93C
200
930
200
93E
200
94A
200
94B
200
94C
200
940
300
94F
150
94G
150
94H
200
94J
200
95A
100
95B
100
95C
100
950
100
95E
150
95F
150
96A
150
96B
150
96C
200
960
200
96E
200
96F
200
98G
400
97A
200
978
200


60 -3.91 -5.89 -0.48

60 0.57 -5.33 0.21

60 1.53 -3.70 5.20

60 0.82 -1.34 6.10

80 0.31 -3.20 -9.71

80 -1.67 -2.59 1.44

60 -8.83 -4.36 0.71

60 -3.30 -2.06 1.01

60 -5.02 -0.42 0.44

80 -2.44 -0.58 1.64

60 -1.72 -0.20 0.03

60 0.14 -4.12 -10.44

80 0.21 -4.92 -3.93

60 -8.15 -3.84 -0.18

60 -5.88 -3.46 -0.22

60 -2.88 -3.73 -0.07

00 -0.80 -1.74 -1.72

80 0.70 -7.87 -9.64

80 -4.99 -15.60 -9.15

60 -3.44 -9.07 -11.32

60 -1.44 -9.30 -8.70

35 -2.52 -1.34 -1.36

52 -3.12 -0.81 -0.53

59 -6.45 -3.91 -1.28

50 -4.71 -0.97 0.37

53 -5.99 -2.52 -0.31

56 -6.40 -3.60 -2.34

53 -4.65 -2.59 -1.81


-12.26


-12.26


1.25 1.24 1.80 -1.84 -4.43

0.68 1.51 2.59 3.34 2.63

2.97 1.28 1.04 -3.01 -4.04

5.27 -0.68 0.35 4.54 4.40

-3.08 0.75 -0.09 -0.85 -0.96

0.19 0.43 1.25 2.09 2.59

1.25 -0.27 1.31 1.91 1.04

1.78 0.96 0.73 0.92 1.20

1.55 0.37 -1.84 -3.31 -4.99

1.18 0.32 -4.31 -6.13 -6.26

-0.34 -0.49 0.47 -0.73 -0.46

-2.35 2.93 1.57 0.88 1.21

0.14 0.84 -0.54 -1.63 0.12

2.12 2.95 2.51 1.90 2.41

-0.06 -1.36 -0.23 2.36 4.04

-0.20 -0.40 -0.92 -2.45 -3.87

-3.33 0.10 0.99 -0.96 -3.60

-5.21 -3.41 -3.17 -2.81 -2.09

-5.26 -3.34 -2.97 -0.06 0.90

-6.60 -5.75 -2.09 -0.80 -0.36

-5.60 -3.80 -1.76 -1.20 -1.89

-1.91 -2.21 -1.87 -2.34 -2.68

-1.95 -2.42 -0.44 0.05 -1.42

-2.52 -1.03 0.94 2.51 2.29

-0.69 -1.94 -3.24 -2.41 -0.65

-1.85 -1.90 -1.56 -2.12 -2.90

-2.93 -1.48 3.55 5.97 5.21

-3.20 -2.50 -0.10 4.84 3.33


6.21

1.27

19.48

-16.63

3.73

-7.22

1.23

-13.21

-16.50

-3.45

-10.18

-9.72

1.94

-4.81

-14.53

-11.05

-33.51

-40.46

-39.43

-33.70

-16.23

-10.84

-9.43

-14.26

-19.15

-2.03

-6.67


(2,S77)

214

1,886

(482)

(1,830)

(1,385)

(1,380)

(603)

(547)

(183)

(1,425)

(2,527)

(1,634)

(873)

(825)

(723)

(1,480)

(4,277)

(4,907)

(4,160)

(2,413)

(1,354)

(2,058)

(2,015)

(1,669)

(5,191)

(2,752)

(1,993)


(2,363)

(677)

(1,160)

(2,990)

(4,375)

(5,755)

(6,358)

(6,905)

(7,088)

(8,513)

(11,039)

(12,673)

(13,546)

(14,371)

(15,094)

(16,574)

(20,851)

(25,757)

(29,918)

(32,331)

(33,885)

(35,740)

(37,756)

(39,424)

(44,615)

(47,367)

(49,360)


534

389

767

540

1,038

781

(596)

(3,923)

(1,320)

403

537

856

730

(141)

(556)

(748)

(1,271)

(1,085)

(1,324)

(1,332)

(1,333)

49

(353)

(1,672)

953

1,881

278


1,903

2,292

3,058

3,598

4,634

5,415

4,820

897

(423)

(20)

518

1,374

2,103

1,962

1,406

659

(613)

(1,698)

(3,022)

(4,354)

(5,687)

(5,638)

(5.991)

(7.663)

(6,710)

(4,829)

(4,551)


(i,209)

(461)

1,614

1,899

608

259

(340)

(1,538)

(6,008)

(7,511)

(8,532)

(10,521)

(11,299)

(11,442)

(12,409)

(13,688)

(15,916)

(21,483)

(27,455)

(32,940)

(36,865)

(39,371)

(41,378)

(43,747)

(47,088)

(51,325)

(52.196)

(53,911)













P.E.P. Reef Monitoring Volumetric changes between survey lines dated July 1992 and April 1993 (continued).

SDistance b/I Distance to Lenght of I Volume Change (cu. yards/linear foot)
ProfileLne U nes (ft) I Reef (ft) Cells (ft) st Cell 2nd Cell 3rd Cell 4th Ce thCell 5thCellh Cell 7th


Cell 8th Cell


InnerVolume Inner Cumul. Outer Volume Outer Cumul. Total Cumul.
Total Change(cu.yds) Change (cu.yds) Change (cu.yde) Change (cu.yde) Change (cu.yds)

S^


52

40

46

50

53

54

228 57

228 57

240 60

260 65

27 689

72

60

60

00

80

60

60

80

60

60


60 3.22 6.23

60 3.28 9.74

60 4.75 3.86

60 4.04 5.58


-1.01 -2.49 -0.79

0.48 -0.78 -3.72

-0.49 -1.68 -2.74

-0.42 -1.11 -0.74

0.52 -1.08 -1.90

1.00 0.07 -2.32

0.83 0.16 2.68

3.23 5.35 8.19

4.73 5.53 5.05

4.54 5.52 0.96

1.93 2.76 6.37

1.27 3.25 2.87

1.84 -0.98 0.45

2.12 -0.00 -3.92

-3.01 -3.27 -1.77

2.01 -0.22 -1.02

-2.11 -1.50 -2.79

-2.44 -2.52 -2.14

1.90 0.69 -1.66

1.92 0.71 0.21

3.73 -0.39 -1.93

1.58 0.52 1.24

1.49 0.51 -0.51

-0.25 0.48 0.78

1.10 0.66 -0.08


53 -2.81 -1.04 -1.4S -2.37 -2.-


60 2.27 2.10 0.26 -1.39 -1.05 -0.92 -2.54 -2.55 -3.83

-6.16 0.64 -29.78 -22.29 -18.58 -42.27 -50.83 -34.27 -203.53


Vertical double lines Indicate location of reef structure at time of monitoring survey
Revised: 1/19/94


-0.45 00 5 0 05

2.84 0.24 -1.52

-2.00 -1.00 -1.40

-0.32 0.17 0.52

-0.79 -0.20 -0.12

-0.90 -1.52 -0.60

-1.13 0.13 0.90

0.74 -2.01 -2.10

0.25 -0.45 0.25

-0.81 -0.67 0.04

1.29 2.82 3.51

4.33 -2.08 -0.57

2.17 -2.49 -1.02

-1.78 -4.97 -3.03

-4.81 -4.12 -1.68

-4.11 -3.22 -3.33

-2.06 -2.29 -3.04

-8.24 -8.70 -6.57

-2.50 -0.15 1.78

-3.07 -2.93 0.05

-1.59 0.77 1.21

-4.76 -2.32 -1.59

-2.39 -1.91 0.23

-2.41 -3.03 -2.84

-1.50 -1.98 0.38

-3.18 -5.14 -2.20


(1,293)

(621)

(346)

(580)

(377)

31

449

2,107

2,084

2,274

1,962

1,766

2,334

1,930

714

814

1,465

298

1,604

3,134

3,325

2,740

2,854

2,384

2,083

1,522


(50,653)

(51,274)

(51,620)

(52,200)

(52,577)

(52,545)

(52,096)

(49,989)

(47,906)

(45,832)

(43,670)

(41,904)

(39,570)

(37,640)

(38,926)

(36,112)

(34,647)

(34,351)

(32,748)

(29,614)

(26,289)

(23,550)

(20,895)

(18,511)

(16,429)

(14,907)


(203)

(808)

(841)

(317)

(508)

(550)

(311)

555

493

909

1,131

479

(586)

(1.788)

(2,021)

(1,563)

(3,270)

(2,740)

(1,072)

(701)

(1,000)

(1,345)

(1,143)

(1,092)

(1,293)

(1,767)


(4,754)

(5,562)

(0,403)

(0,720)

(7,228)

(7,778)

(8,089)

(7,535)

(7,042)

(6.132)

(5,001)

(4,522)

(5,108)

(0,896)

(8,918)

(10,480)

(13,750)

(18,489)

(17,581)

(18,202)

(19,202)

(20,806)

(21,749)

(22,841)

(24,135)

(25,902)


101C


" ` '


(55,407)

(56,836)

(58,023)

(58,920)

(59,804)

(80,323)

(80,185)

(57,524)

(54,948)

(51,764)

(48,.71)

(48,426)

(44,678)

(44,536)

(45,843)

(46,591)

(48,397)

(50,840)

(50,309)

(47,876)

(45,551)

(44,156)

(42,644)

(41,353)

(40,564)

(40,809)













P.E.P. Reef Monitoring Volumetric changes between survey lines dated April 1993 and August 1993.

Distance b/ Distance to Lenght of Volume Change (cu. yards/linear toot Inner Volume I nner Cumul. OuterVolumeI OuterCuul. I Total Cumul.
Profile Una Uines (ft) Reef ft) Cells (ft) 1st Cel 2nd Cell 3rd Cell 4th Cell 5th Cell 6th Cell 7th Cell 8th Cell Total Change(cu.ds) Change (cu.yds) Change (cu.yds) Change (cu.yds) Change (cu.yds)


60 -1.72 0.32 -0.08

00 -0.39 -6.18 -9.73

60 -0.27 -8.07 -14.10

60 -0.03 -7.47 -14.97

80 0.10 0.34 5.99

60 1.94 -3.07 -2.36

60 2.86 -0.14 -1.10

60 -0.23 2.32 -2.97

80 1.10 0.92 -0.90

80 0.44 2.09 1.58

60 0.04 2.12 -0.10

60 0.16 1.56 3.67

60 -0.05 0.50 -1.20

60 -0.64 1.00 0.11

60 2.42 2.54 0.27

60 1.27 2.62 0.01

60 -0.56 1.23 1.13

320 80 1.21 5.04 0.92

320 60 2.80 4.94 0.28

60 1.00 2.87 -0.04

60 0.08 1.49 -1.26

140 35 -0.47 -0.56 -0.39

208 52 0.74 -0.15 -1.05

236 59 2.98 -2.03 -2.60

200 50 2.61 -1.39 -2.18

212 53 2.44 -0.49 -1.48

224 56 2.10 -1.45 -2.20

212 53 0.44 -2.10 -1.24


-2.27 -2.86 -3.54 -2.36 1.42 -11.09


-4.08 -4.29 -3.50

-6.08 -3.38 -1.04

-8.12 -0.19 1.32

1.55 -0.51 -0.51

-0.03 -0.07 -0.14

-0.30 0.15 -0.54

-2.01 -0.55 -0.51

-1.95 0.85 0.94

-0.10 0.76 3.11

0.12 -0.14 -0.61

0.92 -0.73 0.52

0.12 0.71 0.66

-0.37 -0.93 -0.04

-0.96 0.83 -0.02

0.10 -0.21 0.41

1.82 -0.78 -0.95

3.268 1.14 0.29

3.85 0.30 1.48

1.32 1.55 -0.01

-0.65 -1.43 0.52

0.30 -1.25 -0.63

-0.58 0.27 0.09

0.98 0.15 0.06

-1.87 0.21 -0.09

-0.93 1.23 0.81

-0.67 1.13 -3.08

-1.62 0.03 0.24


-2.67 1.10

3.40 4.47

-2.67 -2.64

0.51 0.56

-1.31 -1.22

-1.01 0.01

-0.50 -0.96

-0.12 1.15

4.22 3.96

-0.18 -0.26

0.30 -0.30

0.16 0.08

0.82 0.66

-2.31 -3.70

1.72 0.64

0.21 2.21

2.52 1.89

2.07 1.55

1.63 -0.02

0.65 1.79

-0.21 0.63

-0.44 0.31

0.09 -1.81

0.17 -0.79

1.23 1.77

-5.06 -5.52

0.15 -0.86


(4,C..Z)

(4,890)

(5,912)

(2,262)

445

(220)

(158)

(365)

483

463

637

508

(113)

219

413

381

702

1,672

1,276

380

(110)

(217)

(172)

(349)

(327)

(534)

(673)

(716)


(4,8.2)

(9,716)

(15,628)

(17,890)

(17,444)

(17,664)

(17,820)

(18,185)

(17,702)

(17,239)

(16,602)

(16,094)

(16,206)

(15,988)

(15,575)

(15,194)

(14,492)

(12,820)

(11,544)

(11,184)

(11,294)

(11,512)

(11,683)

(12,032)

(12,359)

(12,893)

(13,566)

(14,283)


(3,3W)

(585)

(67)

(413)

(269)

(413)

(390)

10

2,200

814

(105)

141

213

(235)

(132)

162

326

843

641

350

6

(121)

(128)

(201)

453

(1,500)

(1,297)

(89)


(3,340)

(3,925)

(3,992)

(4,405)

(4,674)

(5,086)

(5,476)

(5,466)

(3,266)

(2,452)

(2.557)

(2,417)

(2,203)

(2,438)

(2,570)

(2,408)

(2,083)

(1,240)

(599)

(249)

(243)

(384)

(492)

(694)

(241)

(1,741)

(3,038)

(3,127)


(13.641)

(19,620)

(22,284)

(22,118)

(22,751)

(23,207)

(23,651)

(20,968)

(19,691)

(19,159)

(18,510)

(18,410)

(18,426)

(18,145)

(17,603)

(16,574)

(14,060)

(12,144)

(11,433)

(11.537)

(11,876)

(12,175)

(12,725)

(12.599)

(14,634)

(16,805)

(17,410)


Vertical double lines indicate location of reef structure at time of monitoring survey.













P.E.P. Reef Monitoring Volumetric changes between survey lines dated April 1993 and August 1993 (continued).


Profile Une Lines (f Reef (ft Cells (it)


Volume Change (cu. yards/linear foot)
1st Cell 2nd Cell 3rd Cell 4th Cell 5th Cell 8th Cell 7th Cell 8th


212 53 0.52 -1.2S


208 52

184 46

184 46

200 50

212 53

216 54

228 57

228 57

240 80

260 65

276 69

288 72

60

60

60

60

80

60

60

60

80

60

60

6o


00 1.42 1.23

60 0.94 2.62


-1.27 -0.63 0.55

-0.63 0.98 -0.08

-1.18 -0.29 0.79

-0.53 -0.53 0.94

-0.32 -0.12 -0.22

-0.93 0.17 -0.51

-0.71 -1.54 -0.50

-0.07 2.10 1.93

-0.98 -0.83 -0.70

-1.39 -1.42 -0.56

-1.51 -1.84 -0.57

-0.95 -0.73 -0.81

-2.18 -3.49 -0.68

-2.64 -1.59 -2.57

-2.94 -1.35 0.77

2.83 1.55 -1.23

-1.89 -1.16 -0.93

2.07 1.81 2.81

0.81 1.58 2.62

-0.77 -0.44 0.14

0.59 -0.83 0.74

-2.41 -1.31 -1.14

-0.85 -0.93 -0.11

-0.30 -1.60 -1.91

0.67 -0.59 -2.64


O.C3

-1.33

0.41


-2.34 -0.12

0.95 0.55

-0.14 -0.16

0.68 0.33

0.70 0.20

-1.40 -1.93

1.81 -0.36

0.74 0.44

0.14 -0.67

-0.99 -1.48

1.00 0.46

1.35 2.14

1.02 0.01

0.77 -0.50

-0.67 0.70

0.80 -0.02

4.48 2.60

-0.33 -0.39

1.13 0.03

-1.49 -0.21

1.50 0.58

0.73 0.40

1.42 1.39

0.01 0.54


Inner Volume Inner Cumul. Outer Volume Outer Cumul. Total Cumul.
Cell Total Change(cuyds) Change (cu.yds) Change (cu.yds) Change (cu.yds) Change (cu.yd)
ilmm


-3.15

1.35


-2.21 -0.78 -1.92 -0.23 1.40 1.34


0.02 -0.34 0.32


1.14 3.42 1.91 10.03


(195)

(64)

(63)

104

41

(190)

168

417

(88)

(144)

(78)

(287)

(785)

(781)

403

032

526

1,184

333

(03)

(535)

(573)

(78)

607

607

291


(14,477)

(14,542)

(14,804)

(14,501)

(14,460)

(14,650)

(14,482)

(14.085)

(14,131)

(14,275)

(14,350)

(14,837)

(15,422)

(18,202)

(15,800)

(15,188)

(14,642)

(13,458)

(13,125)

(13,218)

(13,753)

(14,326)

(14,404)

(13,796)

(13,189)

(12,898)


(430)

(115)

258

120

23

(380)

70

597

(78)

(268)

(125)

221

48

73

197

(189)

1,143

1,577

514

154

332

519

235

(319)

(328)

738


(3,557)

(3,872)

(3,414)

(3,284)

(3,271)

(3,851)

(3,581)

(2,983)

(3,061)

(3.329)

(3,454)

(3,233)

(3,185)

(3,112)

(2,915)

(3,104)

(1,980)

(384)

130

284

818

1,134

1,370

1,050

722

1,481


(18,034)

(18,213)

(18,018)

(17,794)

(17,731)

(18.301)

(18.063)

(17,049)

(17,193)

(17,804)

(17,805)

(17,870)

(18,807)

(19,314)

(18,715)

(18,272)

(16,802)

(13,841)

(12,995)

(12,934)

(13.137)

(13,192)

(13,034)

(12,746)

(12,467)

(11.437)


55.56 1.56 -65.27 -32.18 -13.65 1.96 17.24 13.77 -21.02

Vertical double lines Indicate location of reef structure at time of monitoring survey.
Revised: 1/19/94





03.. 0 ..













P.E.P. Reef Monitoring Volumetric changes between survey lines dated August 1993 and December 1993.

I Distance b/I Distance to I Lenght of Volume Change (cu. yardslinear foot)
Profile Un I Unes (ft) I Reef (t) Cells (ft I 1st Cell 2nd Cell 3rd Cell 4th Cell 5th Cell 6th Cell 7th Cell 8th Cell


92F 6 0 .40 0.58 -4.71 -3.99 -2.12
403
93B 60 0.51 9.95 9.32 -1.90 -3.23
200
93C 80 0.22 12.42 19.11 11.68 1.90
200
93D 60 -0.41 7.99 21.36 12.90 2.41
200
93E 60 0.45 1.71 -6.40 -4.93 -2.54
200
94A 0 -1.37 6.91 0.85 -1.13 -1.43
200
94B 60 2.16 2.01 -2.84 -1.55 -0.19
200
94C 60 4.92 0.02 1.74 0.24 -0.23
200
94D 0 6.22 3.82 0.41 -0.51 0.43
300
94F 60 5.83 -0.19 -3.85 -1.54 -2.91
150
94G 60 3.02 2.55 -0.51 -0.89 0.69
150
94H 60 -0.11 -2.36 -6.54 -5.33 -4.67
200
94J 0 0.57 5.88 8.79 -1.88 -3.20
200
OSA 10 0.92 -1.04 -1.49 -3.51 -2.45
0, 100
958 80 1.97 -3.32 -1.03 -0.63 -0.20
100
95C 0 0.44 -3.31 -0.40 -0.32 -0.77
100
950 60 0.48 -0.48 -0.18 0.62 0.70
100
95E 320 80 -0.03 -1.51 2.09 -6.37 -5.50
150
95F 320 80 0.73 -3.10 -5.84 -9.27 0.08
150
96A 60 3.78 2.36 -0.53 -4.09 -2.90
150
96B 60 4.90 14.89 12.37 4.07 5.04
150
96C 140 35 4.29 1.38 -2.38 -0.81 0.21
200
960 208 52 0.12 -4.03 -2.03 0.03 0.80
200
96E 236 59 -3.55 -1.89 -0.91 -3.52 2.19
200
96F 200 50 -16.17 -5.79 -3.19 -0.15 0.79
200
96G 212 53 -5.25 -8.29 -4.87 -1.68 0.35
400
97A 224 56 -3.21 -5.68 -4.51 -3.87 1.07
200
97B 212 53 2.24 -0.98 -5.25 -1.82 0.52
200

Vertical double lines Indicate location of reef structure at time of monitoring survey.


-2.52 0.38 -0.57

-1.99 -1.43 -2.89

-0.02 0.26 -4.83

-2.46 1.42 3.02

-0.49 -0.87 -0.87

0.99 1.25 -0.41

-0.38 0.13 -0.12

-1.31 -0.57 -0.85

1.26 0.24 -0.34

-2.07 -1.37 -0.43

-0.24 0.48 0.80

-2.41 -1.99 -0.68

-1.57 -1.36 -1.03

-2.20 -1.35 -0.78

-0.48 0.79 2.00

-0.48 -0.91 -1.54

-0.48 -0.60 -0.51

-0.54 -1.88 -1.81

-0.37 -1.20 -0.08

0.15 0.17 1.42

0.18 -1.18 -1.46

0.88 1.16 0.96

-0.11 -0.75 -1.03

-0.20 -0.64 0.72

1.22 -0.02 0.78

-0.87 -0.79 -0.89

2.69 4.09 4.60

0.61 -2.84 -0.05


InnerVolume InnerCumul. Outer Volume Outer Cumul. Total Cumui.
Total Changecu.yds Chane (cu.yds) Change cu.yds Chane (cu.yds) Change (cu.yds)

3,233 3,233 i2,873) 12,873 60,
8.34
8,131 9,384 (1,217) (4,090) 5,273
40.79


48.23

-13.93

11.87

-0.78

4.18

11.54

-6.73

5.90

-24.09


8,527

3,267

210

1,105

670

1,887

1,500

316

(763)

(298)

1,223

(107)

(330)

(159)

(270)

(1,748)

(1,198)

2,831

2,903

(432)

(1,867)

(3,517)

(4,319)

(7,029)

(2,306)

(1,475)


17,890

21,158

21,368

22,473

23,143

24,830

26,329

26,648

25,883

25,585

26,808

26,700

26,370

28,212

25,942

24,194

22,997

25,828

28,731

28,298

26,831

23,113

18,795

11,766

9,460

7,985


(323)


175

(38)

(437)

(16)

(332)

(117)

(778)

(379)

(602)

(1,691)

(1,392)

(232)

(78)

(230)

(521)

(829)

(203)

104


(3,915)

(3,953)

(4,300)

(4,406)

(4,738)

(4,856)

(5,634)

(6,012)

(6,614)

(8,305)

(9,097)

(9,929)

(10,007)

(10,237)

(10,758)

(11,587)

(11,790)

(11,685)

(11,255)

(11,045)

(10,953)

(10,476)

(10,399)

(8,308)

(7,238)

(7,561)


13,975

17,204

16,978

18,068

18,404

19.974

20,895

20,633

19,269

17,280

17,110

1.,771

18,383

15,974

15,184

12,607

11,207

14,142

17,478

17,253

15,077

12,637

8,396

3,458

2,222

424













P.E.P. Reef Monitoring Volumetric changes between survey lines dated August 1993 and December 1993 (continued).

I I Distance bl Distance to Lenght of Volume Change (cu. yards/linear foot)
SProfileLine ne (ft) I Reef (f I Cell (ft) lst Cell 2nd Cell 3rd Cell 4th Cell 5th Cell 6th Cell 7thCell 8th Cell Total


] Inner Volume InnerCumul. Outer Volume Outer Cumul. Total Cumul.
SChange(cu.yds) Chang (cu.yd) (cuyd Change (cu.yds) Change (cu. Chn u.yds)


212 53 0.64 -3.99 -4.09

208 52 0.58 -4.07 -4.41

184 44 0.73 -2.55 -5.18

184 46 -0.42 -1.97 -6.29

200 50 -2.47 -5.83 -5.97

212 53 -0.24 -3.42 -4.57

210 54 0.80 -3.01 -5.56

228 57 0.13 -1.12 -3.76

228 57 -0.03 2.17 -0.83

240 60 1.77 0.96 -3.06

280 65 1.69 2.65 -0.88

2708 8 0.94 7.20 0.75

288 72 3.11 8.87 1.73

60 1.65 7.07 5.02

60 0.93 5.19 6.95

60 1.16 2.85 3.78

60 0.25 0.59 8.55

60 0.36 0.22 0.76

60 0.99 1.97 2.85

60 0.73 1.53 5.21

80 0.58 1.02 3.18

60 -0.01 1.14 4.49

80 0.19 1.59 4.40

80 -1.55 -0.54 4.68

60 -2.79 -3.43 1.20

80 -3.44 -0.15 4.38


-1.51 -0.85 -1.05

-3.28 0.25 -1.62

-2.25 -0.22 -1.39

-3.37 -1.20 -0.54

-2.53 -0.58 -0.70

-1.01 0.04 0.25

-2.12 1.77 0.39

-4.37 -0.30 -0.13

-3.64 -1.69 -2.32

-0.53 -1.79 1.68

-1.57 -0.28 1.79

-0.56 -0.30 0.21

0.93 0.39 0.02

1.27 1.18 1.06

1.37 -2.87 -4.71

-0.05 -1.21 -2.38

3.22 2.08 0.51

-0.78 -2.32 -4.45

-1.12 -5.17 -3.48

1.94 1.17 0.34

1.80 -0.74 -0.91

2.42 -0.72 -0.82

2.09 0.78 -0.00

3.04 3.96 -0.79

0.54 -0.17 1.37

2.07 0.06 -1.66


27.48 39.54 32.33 -42.36 -21.79 -32.44 -24.92 -20.71 -42.88

Vertical double lines indicate location of reef structure at time of monitoring survey.
Revised: 1/19/94


0.09 0.33


-10.42

-13.24

-13.28

-14.83

-17.85

-12.12

-4.66

-10.58

-9.73

-0.64

8.25

8.99

12.72

16.26

4.87

-1.00

7.95

-9.21

-1.84

9.91

3.75

6.74

5.58

5.36

-4.06

0.11


(2,012)

(2,043)

(1,598)

(2,164)

(2,021)

(1,502)

(1,901)

(1,145)

(459)

(248)

511

1,048

2.119

2.254

1,663

1,376

1,120

528

1,410

1,599

1,481

1,831

1,389

114

(163)

(655)


5,973

3,929

2,331

167

(1,854)

(3,355)

(5,256)

(6,400)

(6,859)

(7,107)

(6,596)

(5.547)

(3,429)

(1,175)

488

1,864

2,984

3,512

4,922

6,521

7,983

9,613

11,003

11,117

10,954

10,299


(354)

(609)

(510)

(287)

(227)

243

378

(885)

(359)

328

351

37

54

(669)

(1,373)

(855)

(1,246)

(1,032)

(803)

(233)

(413)

(400)

(296)

15

(233)

(337)


(7,015)

(8,523)

(9,034)

(9,320)

(9,547)

(9,304)

(8,926)

(9,811)

(10,170)

(9,842)

(9,492)

(9,454)

(9,400)

(10,070)

(11,443)

(12,297)

(13,543)

(15,175)

(15,779)

(16,012)

(18,424)

(18,824)

(17,120)

(17,104)

(17,337)

(17,674)


(1,942)

(4,594)

(6,703)

(9,154)

(11.401)

(12,680)

(14,182)

(16.211)

(17,030)

(16,949)

(16,087)

(15.002)

(12.829)

(11,245)

(10,955)

(10,433)

(10.558)

(11,3)

(10,856)

(9,490)

(8,442)

(7,211)

(6,117)

(5,987)

(6,383)

(7.375)


Go -4.65 -5.91 -1.51 2.67 2.02 -0.0 -1i.80 -0.79 -10.02












P.E.P. Reef Monitoring Volumetric changes between survey lines dated July 1992 and December 1993.

Distance b/ Distance to Lenght of Volume Change (cu. yards/llnear oot Inner Volume IInner Cumul. Outer Volume I Outer Cumul. I Total Cumul.
Profile Unei Unes (ft) Ree (ft) Cells (ft) 1t Cell 2nd Cell 3rd Cell 4th Cell 5th Cell 6th Cell 7th Cell 8th Cell Total Chane(cu.yds) Chan (. angCe (cu.yda) Change (cu.yds) Change (cu.yd)
92F 60 0.77 -4.99 -5.26 -5.01 -3.74 -4.27 -3.81 -3.57 -29.89
400 (4,171) (4.171) (4,D4 ) (4,845) 4(,0i5)
93B 60 0.69 -1.56 -0.20 -5.30 -6.01 -2.90 -0.76 0.84 -15.19
200 1,455 (2,716) (1,288) (6,113) (8,828)
93C 60 1.48 0.65 10.21 8.57 -0.14 -0.02 0.71 -4.40 17.06
200 4,301 1,585 497 (5,616) (4,030)
93D 60 0.38 -0.82 12.49 10.05 1.55 -0.79 3.28 4.78 30.93
200 523 2,108 316 (5,300) (3,191)
93E 60 0.86 -1.15 -10.12 -6.46 -2.29 -1.09 -1.01 -1.28 -22.54
200 (1,175) 933 (166) (5,486) (4,532)
94A 60 -1.09 1.25 5.93 -0.97 -1.07 2.10 2.03 0.96 9.13
200 (500) 433 607 (4,859) (4,425)
94B 60 -3.80 -2.49 -3.23 -0.60 -0.30 0.38 1.04 0.94 -8.06
200 (866) (433) 59 (4,800) (5,232)
94C 60 1.39 0.28 -0.21 -0.02 0.18 -1.09 -0.18 -0.41 -0.01
200 719 287 (703) (5,502) (5,216)
940 60 2.37 4.33 -0.04 -0.91 1.45 0.30 -3.19 -4.18 0.18
300 1,436 1,722 (2.501) (8,003) (8,281)
94F 60 3.63 1.31 -0.60 -0.46 -1.83 -3.27 -3.28 -2.73 -7.28
150 596 2.319 (884) (8,888) (0,589)
94G 60 1.34 4.48 -0.58 -1.11 0.07 -0.39 -0.43 0.08 3.45
150 (1,550) 769 (304) (9,191) (8,423)
94H 60 0.20 -4.92 -13.31 -6.70 -2.46 -0.32 -0.82 0.23 -28.17
200 (2,317) (1,548) (1,012) (10,204) (11,752)
94J 00 0.13 1.46 1.66 -1.62 -1.65 -1.45 -2.83 -0.83 -5.13
200 (524) (2,072) (323) (10,527) (12,599)
95A 60 0.13 -3.68 -1.56 -1.75 -0.43 0.28 1.37 2.30 -3.34
100 (761) (2,833) 263 (10,254) (13,097)
00 95B 60 -1.50 -4.24 -0.98 -1.65 -0.72 -0.71 0.85 2.33 -6.62
100 (743) (3,576) (352) (10,616) (14,191)
95C 60 -1.18 -4.42 -0.46 -0.43 -1.39 -0.99 -1.63 -4.77 -15.27
100 (501) (4,077) (623) (11,239) (15,316)
950 00 -0.90 -0.99 -0.77 -0.88 0.02 -0.45 -1.35 -1.90 -7.22
100 (1,048) (5,124) (943) (12,182) (17,306)
95E 320 80 1.88 -4.35 -6.63 -8.32 I-7.77 -3.43 -2.15 -1.81 -32.58
150 (4,353) (9,477) (1,258) (13,439) (22,916)
95F 320 60 -1.46 -13.76 -14.71 -10.690 -2.98 -1.86 0.82 2.40 -42.22
150 (4,828) (14,305) (647) (14,087) (28,392)
96A 60 1.35 -3.84 -11.90 -9.37 -7.10 -1.96 1.00 1.04 -30.79
150 (969) (15,274) (870) (14,957) (30,231)
96B 60 3.53 7.08 2.41 -2.18 -0.20 -1.08 -1.73 -1.56 6.27
150 380 (14,895) (895) (15,852) (30,748)
96C 140 35 1.30 -0.55 -4.12 -2.42 -3.24 -1.63 -1.39 -1.09 -13.14
200 (2,004) (18,898) (1,244) (17.096) (33,994)
96D 206 52 -2.26 -4.98 -4.51 -2.50 -1.35 -0.45 -1.13 -2.15 -19.34
200 (3,895) (20,793) 12 (17,083) (37,876)
96E 240 60 -7.02 -7.82 -4.79 -5.06 1.31 0.74 1.96 1.21 -19.48
200 (5,881) (26,674) (77) (17,161) (43,835)
96F 200 50 -18.27 -8.15 -5.00 -2.71 -0.95 -2.11 -2.26 -0.66 -40.10
200 (6.314) (32,988) (1,142) (18,303) (51,291)
96G 212 53 -8.80 -9.29 -6.45 -4.48 -0.33 -1.42 -1.67 -2.02 -34.46
400 (12,754) (45,742) 1,544 (16,759) (62,501)
97A 224 56 -7.51 -10.72 -9.08 -7.46 0.71 3.15 5.00 4.30 -21.59
200 (5,732) (51,474) 1,654 (15,105) (60,578)
97B 212 53 -1.97 -5.67 -8.30 -6.63 -1.94 0.76 2.15 2.42 -19.19
200 (4,184) (55,658) (134) (15,239) (70,897)

Vertical double lines indicate location of reel structure at time of monitoring survey.













P.E.P. Reef Monitoring Volumetric changes between survey lines dated July 1992 and December 1993 (continued).


I Distance b/ Distance toI Lenght of Volume Change (cu. yards/inear foot)
Profile Una Unes ft I Reef if I Calls (ftl 1st Cell 2nd Cell 3rd Cell 4th Cell 5th Cell 6th Cell 7th Cell 8th Cell Total


Inner Volume Inner Cumul. Outer Volume Outer Cumul. Total Cumul.
Chanqe(cu.vds) Change (cu.yds) I Change (cu.yds) I Change (cu.yds) I Change (cu.yds)


2

2

11

11

2

2

2

2

2

2

2

2

2


12 53


-1.00 -0.m


-8.02


08 52 0.79 -5.66 -8.00

84 40 1.33 -3.70 -5.89

94 40 1.46 -3.75 -7.31

00 50 -2.10 -7.45 -6.71

12 53 0.75 -4.37 -4.98

16 54 2.03 -3.98 -5.21

28 57 4.08 -1.07 -3.00

28 57 8.99 4.57 1.43

40 60 11.40 6.04 0.27

60 65 12.39 5.71 2.15

76 70 10.67 11.74 1.73

88 72 11.80 11.64 0.84

80 7.52 12.90 4.83

60 4.92 10.42 6.14

60 3.37 10.44 3.60

60 2.20 10.19 7.77

60 3.28 5.57 0.72

80 4.73 7.07 1.22

80 4.33 9.03 0.34

60 5.91 10.43 5.69

60 2.78 9.30 5.82

00 3.72 8.64 5.33

60 2.20 10.28 5.88

80 3.19 5.53 1.62

60 2.62 6.65 3.26

60 -1.44 -1.19 -1.23


-4.51 -3.25 -1.40 0.35 -0.42

-4.79 -0.59 -0.12 -2.45 -1.98

-3.32 -3.15 -3.04 -2.20 -1.78

-5.58 -3.00 -0.76 -0.50 -0.15

-3.76 -1.54 -1.42 0.46 0.48

-2.79 -2.37 -1.60 -2.03 -1.45

-3.59 -1.05 -1.41 0.00 0.78

-2.10 4.31 2.63 -1.27 -2.60

0.88 3.80 -1.78 -1.59 -0.82

-2.41 2.70 -0.35 -0.38 -0.48

2.11 6.11 3.06 4.82 4.09

1.47 15.4 4.24 -0.56 0.12

0.69 2.58 3.28 -0.43 0.08

-1.30 -0.95 -3.02 -5.26 -2.71

-0.05 -6.02 -6.35 -4.13 -3.37

-1.77 -4.22 -6.88 -6.85 -5.02

1.84 0.13 -2.32 -5.03 -4.77

-0.45 -2.50 -8.07 -7.09 -4.08

-2.05 -4.70 -4.51 0.58 2.41

2.19 -0.35 -2.30 -2.23 -0.50

1.88 0.22 -1.72 -0.07 -0.83

0.73 -3.79 -3.01 -0.75 -0.85

1.68 1.88 -1.73 -2.07 -1.93

1.95 1.53 -3.43 -3.79 -2.50

0.44 -2.03 -1.91 -1.44 -0.41

1.97 -1.94 -5.07 -4.25 -1.50

0.94 1.29 0.17 -0.92 -1.44


78.88 41.74 -62.72 -96.83 -54.03 -72.75 -58.51 -41.21 -267.43

Vertical double lines Indicate location of reef structure at time of monitoring survey.
Revised: 1/19/94


-20.87

-21.74

-19.60

-22.05

-18.85

-12.45

0.99

15.48

18.80

40.24

34.85

30.45

12.02

1.57

-7.14

10.01

-12.62

4.75

17.11

21.50

10.20

15.52

12.11

4.98

1.75

-3.82


(3,499)

(2,729)

(2.007)

(2,641)

(2,358)

(1,660)

(1,284)

1,379

1,559

1,882

2,397

2,528

3,688

3,403

2,780

2,822

3,111

2,008

3,347

4,840

4,251

3,797

3,968

3,106

2,527

1,158


(59,157)

(801,888)

(63,893)

(68,534)

(68,890)

(70,551)

(71,834)

(70,455)

(88,896)

(67,014)

(64.617)

(62,088)

(58,421)

(55,018)

(52,238)

(49,418)

(46,305)

(44,297)

(40,950)

(35,310)

(32,059)

(28,282)

(24,296)

(21,191)

(18,664)

(17,505)


(987)

(1,531)

(1,003)

(483)

(712)

(887)

137

267

55

970

1,357

737

(483)

(2.384)

(3,197)

(2,807)

(3,372)

(2,795)

(1,181)

(780)

(1,081)

(1,226)

(1,203)

(1,397)

(1,854)

(1,366)


(16,228)

(17.757)

(18,851)

(19,334)

(20,048)

(20,733)

(20,596)

(20,329)

(20,273)

(19,304)

(17,947)

(17,210)

(17,693)

(20,077)

(23,274)

(25,881)

(29,253)

(32,048)

(33,210)

(33,990)

(35,071)

(38,296)

(37,499)

(38,896)

(40,750)

(42,118)


(75,383)

(79,844)

(82,744)

(85,868)

(88,936)

(91,284)

(92,430)

(90,784)

(89,170)

(88,318)

(82,563)

(79,298)

(78,114)

(75,094)

(75,512)

(75,296)

(75,558)

(78,345)

(74,190)

(70,300)

(87,130)

(84,558)

(81,795)

(60,088)

(59,413)

(58.021)


~''~'










APPENDIX IV



P.E.P. Reef

Top of Structure

Elevation Data










-2


3 .--- --.- ..... .......- -- ...................... ----------------- -
-- ++ +++ + 4+++
>t + + ++
+ -++ +3 1 + t-
-%-+ --- +
4 ... ............... ...... .... ..... .... .........



o 5 - - - - - - - - - - - - - ----- . ~ . . o o o .
c o



^ <- ',. . ......... .. .. ... .. ... ..


+ Design
S0 o o 9/920 0
0 1 92

7 -------- ---- ----- A 12/ 92 -----------
S4/93
8/93
N v 12/93
0 10 20 30 40 50 60
unit #

Figure IV-1 Top of Structure Elevations Original 57 Units.


IV-2










- 4 ...................................................... ....................


-5F ---


- 7 -.........................................................


-8'
5


3


unit #


Figure IV-2 Top of Structure Elevations Units 50-100.


-7


- I


100


110


120


unit #


130


140


Figure IV-3 Top of Structure Elevations Units 100-150.


IV-3


............................. r ... ...... -.--- -
0

. .


o as-built
* 8/93
v 12/93
. l I


100


S I I I I I I I I I I III I 9 '




d O OCoP Oo o d0d
0 0 0 o 0

-00 O O 0 OE
-o D o o c o
S........... ......... ......... o .......

-P ... .V.V *.. 99 : -,-,_

- VV V
VV


0 as-built
8/93
v 12/93
-NI I I I I
i v i I *, I t i I ,


150


I I II 1 1 1 1 I I 1 1 I I I I I


I I I II _l l i l l I


llI


I II I


NI
I


(
























7 ...........................


--8I
15


160 170 180


170 180
unit #


Sas-built
S8/93
12/93
i i i I '


Figure IV-4 Top of Structure Elevations Units 150-200.


I.


0
0

C PO
... ......... ...... --- ..................... E ... a -


,ooe oo_ vVVVV
S... .... .... .....-E.....-- .. ..... ..... .. V..
VV V V -
V V V 7 V 7


-6 V
- 6 .................. . . . .. . . . .


- 7 .............................................. .............


210 220 230


220 230
unit #


o as-built
* 8/93
v 12/93
* 'sisi240


250


Figure IV-5 Top of Structure Elevations Units 250-300.


IV-4


q- 00

r E 0 00 ED. E
oP L-o 0 0 OOOoU-o []
. v.. ..............
VV
V V Vv
v q V V VV


SI N
, ' I


200


-81
20


N
, *I n n n


I.. . I I I I


. .VV.V ...
V vW


-6 -..-.


150


190


160


I '


I I I .


)0


240


210











4


SV vv.y V vv
: V

-7 -


-81
25


260


270 280
unit #


290


Figure IV-6 Top of Structure Elevations Units 250-300.


300


310


320 330
unit #


340


Figure IV-7 Top of Structure Elevations Units 300-330.


IV-5


--11 111 11ll III I II


...... ..................................^ ,........... .. ............

; ErCUb Ormff

S.........*. ...-...
-* d- *.0 00 _.v


v. .


o as-built
8/93
v 12/93
- . I .


I I I I I I I I I I


300


ID i 0 00Wm 0
*.*.**..*V ..................




V







N N v 12/93
.. ... I ..............................
v




o design
8/9a
N N -- "-- N v 12/93
. I : i i n I i u I v I i


-R I


350


I N NI II .


-N


50


- V










APPENDIX V


Scour Rod Data Table











PEP Reef Scour Rod Monitoring Program

Dates measured: 7/29/93 8/14/93


Days: 20


Rod Initialized Measured Change in Rate of
Depth (in) Depth (in) Depth (in) I Change (in/day)


12.0
16.0
13.3
14.5
11.5
14.5
15.5
10.8
15.8
7.3
9.3
14.8
10.5
13.3
13.8
10.0
11.0
10.0
10.5
15.3
9.0
8.8
9.0
9.0
12.3
6.5
9.3
7.3


13.0
16.3
13.3
18.5
16.0
19.5
22.1
11.0
19.0
9.0
11.0
15.0
12.3
12.3
13.3
12.2
11.5
12.0
12.0
16.5
12.0
7.6
9.6
10.3
12.5
9.5
9.5
8.5


-1.0
-0.3
0.0
-4.0
-4.5
-5.0
-6.6
-0.3
-3.3
-1.8
-1.8
-0.3
-1.8
1.0
0.5
-2.2
-0.5
-2.0
-1.5
-1.3
-3.0
1.2
-0.6
-1.3
-0.3
-3.0
-0.3
-1.3


0.05
0.01
0.00
0.20
0.23
0.25
0.33
0.01
0.16
0.09
0.09
0.01
0.09
-0.05
-0.03
0.11
0.03
0.10
0.08
0.06
0.15
-0.06
0.03
0.06
0.01
0.15
0.01
0.06


Dates measured: 8/14/93 12/15/93


Days: 123


S Rod Initialized Measured Change in Rate of
Depth (in) Depth (in) Depth (in) Change (in/day)


12.0
15.1
11.8
16.5
15.5
19.5
22.1
8.5
16.0
8.8
10.0
12.8
12.0
13.0
13.0
7.5
9.3
10.1
10.0
16.0
11.5
9.5
10.5
7.0
9.3
7.0
6.3
5.3


26.5
28.0
22.0
n/a
n/a
n/a
n/a
19.0
23.0
n/a
n/a
n/a
n/a
n/a
n/a
24.0
20.5
24.0
25.0
40.0
34.0
28.0
26.0
37.0
34.5
n/a
25.0
21.4


-14.5
-12.9
-10.3
n/a
n/a
n/a
n/a
-10.5
-7.0
n/a
n/a
n/a
n/a
n/a
n/a
-16.5
-11.3
-13.9
-15.0
-24.0
-22.5
-18.5
-15.5
-30.0
-25.3
n/a
-18.8
-16.2


0.12
0.10
0.08
0.00
0.00
0.00
0.00
0.09
0.06
0.00
0.00
0.00
0.00
0.00
0.00
0.13
0.09
0.11
0.12
0.20
0.18
0.15
0.13
0.24
0.21
0.00
0.15
0.13


c:\qpro\mrd\scour.wql
revised: 2/17/94




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