HomeMy WebLinkAboutGoldsmith Inlet Jetty Shoreline ImpactGOLDSMITH INLET JETTY
SHORELINE IMPACT STUDY
SUFFOLK COUNTY
NEW' YORK
.~1~ Greenman-Pedersen, Associates, P.C.
CONSULTING ENGINEERS
REPORT ON THE SHORELINE IMPACTS
OF THE GOLDSMITH INLET JETTY
TABLE OF CONTENTS
Introduction
Analysis of Shoreline
Results
Discussion of Results
Impact of Storms
References
Figures
Tables
Dynamics
1
3
4
5
8
9
REPORT ON THE SHORELINE IMPACTS
OF THE GOLDSMITH INLET JETTY
Introduction
Goldsmith Inlet is located along the north shore
of Southold, on the Long Island Sound, which is about
of the Town
13 miles
wide at this point. This report presents the results and discus-
sion of a shoreline analysis conducted to determine the possible
relationship between the stone Jetty at Goldsmith Inlet and the
erosion of Kenneys Road Beach (Figure 1). Specifically, the
study area extends from approximately 2000 feet west of the Inlet
to Morton Point, which is approximately 13,000 feet east of the
Inlet. The study area is characterized by a quartz sand beach,
backed in most areas by one or more rows of dunes. West of
Goldsmith Inlet, however, and at Horton Point, the beach is
backed by bluffs of 40 and 80 feet, respectively. Between these
bluffs, the study area appears to have formed, in the geologic
past, as a prograding shoreline resulting from the infilling of
an embayment between two headlands.
The Goldsmith Inlet Jetty was constructed in 1964 by New
York State to alleviate the erosion problem at Peconic Sound
Shores, west of the inlet, and to aid in maintaining a tidal
channel through the inlet. At some time between 1962 and 1966, a
private groin was constructed approximately 3400 feet east of the
inlet. Within the past several years, numerous additional
private groins were constructed along Kenneys Road Beach.
Shoreline erosion on the north shore of Long Island has been
classified as "critical" by the U.S. Army, Corps of Engineers
(1), which means that the area is "undergoing significant erosion
where action to halt erosion may be Justified."
-2-
Other studies (e.g. 2) have confirmed this long term trend
towards shoreline recession in the study area. As a result of
this trend, numerous erosion control devices, including the
Goldsmith Inlet Jetty, have been constructed. Jetties and groins
function in a similar manner (Jetties being those structures
located at inlets) in interrupting the longshore movement of
sediment, which is predominantly from west to east in the study
area. The result is a building up of the beach on the "updrift"
side and erosion on the "downdrift" side. There is no estab-
lished guideline for determining the extent of the downdrift
"erosion shadow" associated with a littoral barrier. The rate
and extent of erosion depend on many factors, including beach
characteristics, offshore profiles, frequency of storms, and
shoreline orientation. Previous studies (3 and 4) have deter-
mined that groins on the North Shore of Long Island elicit shore-
line responses similar to those on other sedimentary coasts.
In addition to being the location at which the subject Jetty
was constructed, Goldsmith Inlet is situated near a point of
major shoreline orientation change, which can significantly
affect the relevant coastal processes (5). The shoreline to the
west of the study area trends more towards an east-west direc-
tion, while the study area shoreline trends more northeast-
southwest.
-3-
Analysis of Shoreline Dynamics
Shoreline position and configuration are constantly changing
in response to storms, normal wave activity, and engineering
works. The analysis of these changes can best be done through
the use of sequential data covering an appropriate time span to
study the problem at hand. The best source for this data is
vertical aerial photography (6). For the purpose of performing
the quantitative analysis, selected aerial photographs were blown
up to a scale of l" = 400', using shoreline cultural features as
control. Data collection and analysis was then performed using a
variation of the orthogonal grid-address system (6) developed by
Dr. Robert Dolan et. al. A transparent topographic map was
prepared which contained all of the cultural features used for
control, at the scale of the photographs. A baseline was estab-
lished on this transparent overlay and perpendicular transects
then placed at 300' increments. Data gathering consisted of
overlaying the topographic map on each aerial photograph and
carefully measuring the distance along each transect to the high
water shoreline. Nigh water shoreline is generally recognizable
on black and white aerial photography as a discernable boundary
between damp and dry sand (7)- The data was then input for
computer analysis. Programs were prepared to calculate changes
of shoreline position, rates of change and standard deviations.
The change in the landward/seaward position of the shoreline at
any one point (transect) can be expressed as the mean rate of
erosion/accretion, and by the standard deviation of this mean
rate. The standard deviation is a particularly useful parameter,
as it indicates the variability of the mean, and, thus, the
stability, or predictability, of the mean at any point.
-4-
Result__~____~s
The results of the shoreline analysis are presented in
Figures 2-11 and Tables 1-10. Figures 2-6 are illustrations of
the rate of historical shoreline change for varioUS time periods,
with an envelope of one standard deviation. The transect numbers
refer to the baseline location of individual transects and are
identified on Figure 1. Figures 7-11 are computer printouts of
the data from Figures 2-6, and include tabulations of the
statistics for the individual transects. Tables 1 through 9 are
statistical summarieS, broken down into several ,,reacheS" based
variously on geomorphology, proximity to erosion control devices,
and developed areas. These displays provide the means to analyze
the shoreline behavior both spatially and temporally-
-5-
Discussion of Results
Between 1955 and 1962, erosion dominated in the study area,
as seen on Figure 3 and Table 1. Severe erosion occured west of
the Goldsmith Inlet Jetty, at a rate of nearly 18 feet per year
between 1959 and 1962. It is quite likely that this severe
erosion, measured on the March 24, 1962, photography, reflects
the impact of the severe northeaster of March 6-8 of ~hat year,
the most severe extratropical storm on record. This may have
been the major impetus for construction of the Jetty. During
this erosion dominated period, several limited areas of shoreline
did experience accretion (Fig. 3). Most notable among these was
the 1000 ft. section immediately east of the Goldsmith Inlet.
However, the extreme variability of the shoreline movement on
both sides of the inlet, as expressed by the high standard de-
viations in this area, indicate that this
shoreline, a condition, incidently, which
shorelines near tidal inlets.
From 1962 to 1978, erosion dominated
was a very unstable
is characteristic of
in the study area
(Fig. 4), with the exception of the Peconic Sound Shores area,
which, being updrift of the Jetty, which was constructed in 1964,
experienced dramatic accretion. During this period, a private
groin was also constructed near transect 151. The extent of the
erosion shadow from the Goldsmith Inlet jetty is obscured on Fig.
4 by this private groin. Fig. 5 shows the shoreline movement
from 1962 to 1972. This is the period during which the Goldsmith
Inlet Jetty was accreting sand on its updrift side and would have
had its severest impact on the downdrift beaches. By the end of
this period, 1972, the Goldsmith Inlet jetty had reached its
impoundment capacity, and was effectively bypassing sand.
-6-
Discussion of Results (Continued)
As shown on Fig. 5, the erosion downdrift of both the Goldsmith
Inlet Jetty and the private groin extended only as far east as
transect 184. From this point to the east, the shoreline under-
went accretion. It is apparent from Fig. 5 that the maximum
extent of the Goldsmith Inlet erosion shadow is transect 184. If
the private groin were absent, it is likely that the impact would
not reach even this far east.
As stated above, by 1972, the Goldsmith Inlet Jetty was
filled to capacity and bypassing sand. This bypassing has
necessitated dredging of the inlet to allow for a tidal flow.
Figure 6 shows the shoreline movement between 1972 and
1978. As indicated on this figure, and in all of the tables,
extensive erosion occurred throughout the study area during this
period. The shoreline west of the Goldsmith Inlet Jetty, which
had experienced dramatic accretion between 1962 and 1972~ eroded
at rates comparable to the remainder of the study area. This
erosion of the Peconic Sound Shores beach accounts for the high
variability for this area indicated on Fig. 4. When the 1972-
1978 data is removed from Fig. 4, the standard deviation envelope
becomes much narrower, as displayed on Fig. 5- It is apparent
that the dramatic erosion, shown on Fig. 6, dominates the 1962-
1978 data (Fig. 4). In other words, although the period from the
construction of the Goldsmith Inlet Jetty up to 1978 was charac-
terized by erosion throughout much of the study area, most of
this erosion occurred after 1972, when the Goldsmith Inlet Jetty
had already attained its impoundment capacity and was bypassing
sand. It should be noted that, on Fig. 6, the standard deviation
-7-
Discussion of Results (Continued)
values are zero because the rates are computed on the basis of
two sets of photography, giving one rate, and, thus, no
variability for this period.
It is apparent from Fig. 5 that the Goldsmith Inlet Jetty
and the private groin combined to produce downdrift erosion,
which extended eastward to about transect 184. The erosion
downdrift of the Goldsmith Inlet Jetty confirms a previous study
(2, page ?4). The relative responsibility of each structure
cannot be determined from the data, but it is apparent that the
eastern limit of the erosion is determined by the private groin.
The highest erosion rates within the period of study occurred
between 1972 and 1978, after the Goldsmith Inlet Jetty had begun
bypassing sand. The cause of the accelerated erosion during this
period is not apparent from the data.
-8-
Impact of Storms
Although normal, fair-weather, waves cause day-to-day
changes in the position and configuration of beaches, storms are
the major agent of shoreline changes. This is due both to the
steepness of the storm waves and the elevated water levels, which
allow wave attack above the normally active beach zone. There
have been no major storms affecting the study area since 1962.
Moderately sized northeasters have occured nearly every winter
since, however, and are probably responsible for a large
percentage of the observed shoreline change. Evidence collected
for the Cape Hatteras area (8) indicates that the recent
(1970-1974) trend towards increasing erosion may be related to
secular cha~ges in the length of the storm season and the
frequency and duration of high wave activity during this season.
If, indeed, the winter storm wave season has lengthened in the
northeast, it could relate to the observed increase in erosion in
the study area from i972 to 1978. The erosion experienced on
both sides of the Goldsmith Inlet Jetty during this period (Fig.
6) indicates that the sediment was moved offshore rather than
alongshore, which points to the turbulent activity of storm
waves.
-9-
REFERENCES
U.S. Army, Corps of Engineers. "National Shoreline Study",
Regional Inventory Report, North Atlantic Region. Volume I,
1971.
Davies, D.S., et. al. "Erosion of the North Shore of Long
Island". Technical Report Series #18, Marine Sciences
Research Center, Stony Brook, N.Y., 1973.
Omholt, Thore. "Small Groins on the Shores of Long Island
Sound". Shore and Beach, April 1974, pg. 11-13.
Omholt, Thore. "Effects of Small Groins on Shoreline Changes
on the North Shore of Suffolk County, New York". New York
Ocean Science Laboratory Technical Report No. 0028, April
1974.
Dolan, R., et. al. "Shoreline Forms and Shoreline Dynamics",
Science. Volume 197, pg. 49-51, July 1, 1977.
Dolan, R., et. al. "Atlas of Environmental Dynamics,
Assateague Island National Seashore". National Park Service
Natural Resource Report #11, Charlottesville, Va., October,
1977.
Dolan, R., et. al. "The Reliability of Shoreline Change
Measurements from Aerial Photographs", Shore and Beach,
October, 1980, pg. 22-29.
Hayden, Bruce. "Storm Wave Climates at Cape Hatteras, North
Carolina: Recent Secular Variations", Science, December 5,
1975, pgs. 981-983.
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Greenman-Pedersen !
Associates, PC
SUFFOLK
COUNTY, NEW
GOLDSMITH
SHORELINE
INLET
IMPACT
DRAWING NO ] SCALE:
80376 I
400'
/
YORK
JETTY
STUDY
DATE: TI SHEET NO.
DEC. t980 i FIGURE
88o
STUDY AREA AND TRANSECT LOCATION.~
187
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· ' $OUncl
" Shores
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30
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145
140
10,3 IO~
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RATE OF
WITH
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SHORELINE MOVEMENT (FT./YR.) 1955 -197F_.
ENVELOPE OF ONE STANDARD DEVIATION
(~ 0
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Greenman-Pedersen
Associates, PC
CONSULTING ENGINEERS
SUFFOLK COUNTY, NEW YORK
GOLDSMITHINLETJETTY
SHORELINE
IMPACTSTUDY
DRAWING NO. SCALE: DATE: SHEET NO.
100 West Main ~treet,
Babylon, NY 11702 80376 IIl I
= 400 DEC. 1980 FIGURE 2
IO3 I0~1
Sh~
RATE OF
WITH
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iL
, SHORELINE MOVEMENT (FT./YR
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.)
1962 -197I
DEVIATION
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0 ~\ ~
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Associates, PC
CONSULTING ENGINEERS GOLDSM~EH
~ SHORELI
SUFFOLK COUNTY, NEW YORK
DRAWING NO. SCALE:
100 West Main Street.
Babylon, NY 11702
INLET
IMPACT
JETTY
STUDY
DATE: SHEET NO.
80376 I" = 400' DEC. 1980 FIGURE 4
40
40,
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RATE OF
WIT'
130
~
/~o
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SHORELINE
ENVELOPE
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OF ONE STANDARD DEVIATION
at Po d
72
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...... ..... I iGOLDSMITH INLET ,JETTY
: 80376 FIGURE 5
0
115
130
RATE OF
WITH
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SHORELINE MOVEMENT (FT./YR.)1972 -197~
ENVELOPE OF ONE STANDARD DEVIATION
0
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DRAWIHG NO.
80576
SCALE:
= 400'
DATE: SHEET NO.
DEC. 1980 FIGURE 6
G reenma n- Pedersen
Associates, PC
CONS'ULTING ENGINEERS
GOLDSMITH
SHORELINE
INLET
IMPACT
JETTY
STUDY
SUFFOLK COUNTY, NEW YORK
~0.
~0'
~0'
/0'
~0~
tl~ Sh,..:.. $,. Golds~ith I~let' Jetty
RATE OF
WlTF;
130 133 ~
14, g
145
157
0
SHORELINE MOVEMENT (FT./YR
ENVELOPE OF ONE STANDARD
.) 1955 -196;
DEVIATION
0 ~\ ~
Great Pond
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.
'~ Greenman Pedersen ~
..i' ' I SUFFOLK ~COUNTY, NEW YORK
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~: I i D.~W~.G .o. I sc^IL, I I DATE, I S.EET .O.
.: "°,°,bw~,~,'/,~'~s",',~;" 80376 I" =', 400' DEC. 1980 FIGURE 3
GJLD~;IIITH IHLET JETTY EROSION STUDY- TOT;J5 STATISTICAL S~,~MARY
- = L~i'~I~.'!ARD HIGRATION (F2t0SION) + = SEAUARD MIGRATION (ACCRETION)
. MAX.~AC- = MAX~. ~I~_SEA~J^~I].I.LIGRATION (O = NO ACC~I~oTION)
~:AX.ER. MAXIMUM LAND:'~ARD MIGRATION (0 = NO EROSION)
STATISTICS FOR TR~3~SECTS 103
THROUGH 244
FROM: 5/55 5/55 6/59 3/62 5/66 5/72
To : . 3/78 6/59 3/62 5/66 5/72 3/78
'fEARS: 22.83 4.08 2.75 4.17 6.00 5.83
TOTAL CHANGE IN StIORELINE (PEET)
~ : -69 5 -18 -2 7 -62
ST.DEV ........ 9~ 25 19 44 50 24
M~[.AC. 230 65 10 175 150 20
~.~X.ER. -220 -65 -70 -65 -70 -1OO
RATE OF CIL~NGE IN SHORELII~ (FEET/YR)
IiE~N : -3.0 1.3 -6.6 -0.4 1.2 -10.6
[~'~ .D~V. 4.1 6.1 6.9 10.5 8.4 4.1
II;Z'.. AC. 10.1 15.9 3.6 42.0 25.0 3.4
I.[AX.ER. -9.6 -15.9 -25.5 -15.6 -11.7 -17.2
GOLDSHITH INLET JETTY L~oolON STUDY- iDTAL STATISTICAL SUI'$IARY
- = L~,~DI'~A~ MIGRATION (EROSION) + = S~AW~m MIGRATION (tCOR~TIoN)
~.~2[.~0. = M~I~ SEAU~D MIGRATION (0 = NO ACCRETION)
I.I~,~.~R. =_I,I~II,E.~ L~g~D,';~ 1,IIGRA~ION (0 = NO EIIOSION)
~'ATISTICS FOR ~ "~ '"
FRJM : 5/55 5/55 6/59 3/62 5/66 5/72
To : 3/78 6/59 3/62 5/66 5/72 3/78
YEf~Ro . 22.83 4.08 2.75 4.17 6.00 5.85
TOTAL CHAHGE ii! CItORELINE (FEET)
~,E~AN : 86 -4 -49 99 99 -59
ST .DEV. 132 39 14 45 53 17
Ilf~[.AC. 230 25 0 175 150 O
I~X.ER. -85 -65 -70 0 O -80
I,/~.1:, OF CIIAHGE
IN SHORELI~.~, (F]~T/YR)
I~AN : 3.2 -1.0 -17.8 23.7 16.5 -10.1
ST.DEV. 5.8 9.5 5.2 10.9 8.8 2.9
I.L~{.~C. 10.1 6.1 0.0 42.0 25.0 0.0
N.~(.ER. -3.7 -15.9 -25.5 0.0 0.0 -13.7
GuLDSMITH IIILET JETTY EROSION STUDY- 'A3TAL STATISTICAL SUMMARY
- = I,AND'JARD IlIGRATION (F~0SION) + = SEAWARD MIGRATION
HP2[.AC. - M~I~,~-SBAW~D--MIGRATION (0 = NO ACCRETION)
M;J[.ER. = M~[I}.~4 L.~IDWA~ MIGRATION (0 = NO E~OSION)
;;YV~Y'ISTIOS FOR TRA/ISEOTS 118 THROUGH 148
/
FRJM : 5/55 5/55 6/59 3/62 5/66 5/72
TO - : ..... 5/78 6/59 3/62 .... 5/66 5/72 3/78
YEARS: 22.83 4.08 2.75 4.17 6.00 5.83
fluiV~L CIt~q,IGE IH SHORELINE (FEET)
RATE OF CIIANGE IN SHORELIIIE (FEET/YR)
Ii,~AiI : -5.1 5.2 -7.9 -11.0 -3.0 -9.0
ST.DEV. 2.5 7.3 4.6 3.5 3.1 5.7
II;ZC,.AC. 0.0 15.9 0.0 0.0 1.7 3.4
II~.X.ER. -8.1 -2.5 -16.4 -15.6 -8.3 -15.4
(ACCRETION)
G~i',DSMIWI! INL'.M JETTY E~oSION STUDY- TO~AL STATISTIOAL SU~.~.~Y
= LANDUAI~ MIGRATION (F~OSION) + = SEAFOOD MIGRATION (ACCRETION)
~.UO[.,~._~= I.~_XII~.i SEAW~D MIGRATION (O = NO ACCRETION)
MA.~.ER. = IIA,~I[~M L~i~D,f~RD MIGRATION (0 = NJ ERJSIOU)
STATISTICS FOR TRanSECTS 118 TtIROUGH 196
FR0i! : 5/55 5/55 6/59 3/62 5/66 5/72
TJ ; ...... 3/78 6/59 3/62 5/66 5/72 3/78
Y ,~i~o. 22.83 4.08 2.75 4.17 6.00 5.83
'f3T;.L CHANGE IN SItJRE]',INE (F,,,,~)
~ ?'?.I! : -116 9 -16 -25 -20 -65
:;~..Dt]V ......... 70 27 13 ..... 22 34 28
;;;._':.AC. 0 65 10 10 45 20
; ~.;[. :,',R. -220 -30 -45 -65 -70 -100
CHANGE
o HOR.,LlrYE (FEET/YR)
~;~'. DqV. 3.1 6.7 4.7 5.5 5.7 4.9
I.b_,,. AC. 0.0 15.9 3.6 2.4 7.5 3.4
I-L~.ER. -9.6 -7.4 -16.4 -15.6 -11.7 -17.2
GJLDSI.IITII Il]LET JETTY EROSIOII STUDY- TOT/U, STATISTICAL SU~.~AiIY
..... - .,,~,~A;~iON tEROSION) + - SEA%i~D MIGRATION (ACCRETION)
~.~.AC. = M~{I~M SEA¥[~ MIGRATION
MAX~ER~ '~"M~XI~'~'i~ L~Wfl~ MIGRATION (0 = NO EROSION)
,';iL~TISTIO$ FOR TR~ISECTS 151 TImOUGH 196
Fll~f.l : 5/55 5/55 6/59 3/62 5/66 5/72 '
ZO : 3/78 6/59 3/62 5/66 5/72 3/78
Y"B,,,ARS~ ..... 22T83 4.08' 2.75 4.17 6.00 5.83
TJTAl] CHANGE 117 SHORELII'~ (FEET)
~AI! : -116 1 -12 -10 -21 -74
S2.DEV. ~D 23 12 13 4.2 22
~£(.AC; 0 ~5 10 ' ' 10 45 0
!L~[.ER. -2 20 -30 -25 -40 -70 -100
RASJE OF OItANGE 117 SHORELINE (FEET/YR)
IIE,,A!!" ..... Z5.1 O. 2 -4 · 2 -2.5 -3.4. -1 2.7
ST.DEV. 5.5 5.5 4.2 3.1 7.0 3.7
MAX.DC. 0.0 11 .0 3.6 2.4 7.5 0.0
It/IX.ER. -9.6 -7.4 -9.1 -9.6 -11.7 -17.2
FOR TII.il]SECTS 151 TIIROUGtI 244
5/55 5/55 6/59 3/62 5/66 5/7~
- 5/78 6/59 3/62 5/66 5/72 3/78
22.83 4.'08 2.75 4.17 6.00 5.83
To2'/I, CIIAIIGM III ,.,IIOR:,LII! ,,
Ii']AU : -77 1 -12 -2 2 -66
ST. I)~;:V. 71 18 17 16 42 21
MJ£t. AC. 5 45 10 35 65 0
[L^C£. ER. -220 -30 -60 -40 -70 -100
RATE OF CIIAHGE IN SHORELINE (FEET/YR)
MEAl: : -3.4 0.3 -4.4 -0.5 0.3 -11.3
,~ .DPV. 3.1 4.5 6.0 3.8 6.9 3.6
~L~[. AC. 0.2 11.0 3.6 8.4 10.8 0.0
I~b~.ER. -9.6 -7.~ -21.8 -9.6 -11.7 -17.2
GoLDSHITH IHLET JETTY EROSION S~I3DY- TOTAL STATISTICAl, SUMMARY
- '= LA}~DWARD MIGRATION (F~ROSION) . + = SEAWA~ MIGRATION (ACCRETION)
~ MAX.A~ ..... MAXt~M-EEAW~D.-MIGRATION (O = NO ACCRETION)
~.~,X.ER. = M~[I~.~,I L~'{D%';~D MIGI~I~N (0 = NO EROSION)
STATISTICS FOR TRanSECTS 178 ~ILROUGH 196
FROM : 5/55 5/55 6/59 3/62 5/66 5/72
TO : .... 3/78 6/59- 3/62 5/66 5/72 3/78
Y~,~%/S: 22.83 4.08. 2.75 4.17 6.00 5.83
CHANGE Iil SHoRELII~ (FEE, T)
Ill,AU : -56 14 -10 -2 12 -70
ST.D~V.- .......48 19 15 8 21 16
H~{.AC. 0 45 10 10 45 .0
:~[.ER. -115 -15 -25 -15 -15 -95
RATE OF CHANGE Iii SHORELINE (FEET/YR)
MIEAII : -2.5 3.3 -3.6 -0.5 2.0 -12.0
ST. DEV. 2.1 4.7 5.5 1.8 3.5 2.8
MAX. AC. 0.0 11.0 3.6 2.4 7.5 0.0
MAX.ER. -5.0 -3.7 -9.1 -3.6 -2 5 -16.3
]~LD~3MI'i~{ INLET JETTY EROSION STUDY- ~OTAL STATISTIC;J~ SUGARY
- = LANDWARD MIGRATION (EROSION) + = SEAWARD MIGRATION
MAX.AC. = MAXIMUM SEAWARD MIGRATIOI~ (0 = NO ACCRETION)
MAX.ER. M~XIMUM LANDWARD MIGRATION (0 -- NO EROSION)
STATISTICS FOR TRANSECTS 178 THROUGH 226
FROM : 5/55 5/55 6/59 3/62 5/66 5/72
TO : 3/78 6/59 3/62 5/66 5/72 $/78
YEfd~o . 22.83 4.08 2.75 4.17 6.00 5.83
T~TAL CHANGE IN SHORELINE (FEET)
~'~A~! : -38 9 -6 6 11 -58
ST.DEV. 38 14 12 13 21 19
MAX.AC. 5 45 10 35 45 0
MAX.SR. -115 -15 -25 -15 -25 -95
(ACCRETION)
R~TE OF CHANGE
IN SHORELINE (FEET/IR)
;~E;. N : -1.6 2.2 -2.1 1.4 1.9 -9.9
ST.DEV. 1.7 3.4 4.2 3.2 3.5 3.3
M~_X. AC. 0.2 11.0 3.6 8.4 7.5 0.0
M3tX. ER. -5.0 -3.7 -9.1 -3.6 -4.2 -16.3