guide to coastal hazards

[From the U.S. Government Printing Office, www.gpo.gov]

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Michael S. Dukakis, Governor
Commonwealth of Massachusetts

James S. Hoyte, Secretary
Executive Office of Environmental Affairs

Richard F. Delaney, Director
Massachusetts Coastal Zone Management

Property of CoS Library

U.S. DEPARTMENT OF COMVMERCF NQM
COASTAL SERVICES CENTER
2234 SOUTH HOBSON ~VENiF
CHARLESTON, SC ant05- ,

A Guide to Coastal Hazards

Volume 1: Manomet Point, Plymouth, to Sandy Neck, Barnstable

March, 1983
Massachusetts Coastal Zone Management
c.> Massachusetts Coastal Zone Management

Preface Acknowledgements
The coastal zone of Massachusetts is a suggestions on this document are wel- The preparation of this publication was
unique blend of sandy beaches, pro- come. Please feel free to contact the funded by the Office of Coastal Zone
ductive estuaries, urban ports and pro- Coastal Zone Management Office at Management, National Oceanic and
tected harbors. Many of our coastal (617) 727-9530 with any questions or Atmospheric Administration, U.S.
communities were founded on mari- for assistance. Department of Commerce, under a
time-related activities and commercial program implementation grant to the
fishing, tourism and energy-related Sincerely, Commonwealth of Massachusetts.
activities continue to support the social fl
and economic growth of out coast. 4a t C9 The Provincetown Center for
Today, over 40% of the Common- Coastal Studies provided an original
wealth's population live in coastal Richard F. Delaney, Director draft of this guidebook authored by
communities. Massachusetts Coastal Zone Graham Geise, Joan McElroy and
Management Program ~Eugene Peck. Additional assistance was
With increasing popularity comes MaaeetPormprovided by Mark Mello. Staff of the
increasing pressure to develop available Massachusetts Coastal Zone Manage-
real estate. Continued development, ment Program reviewed and com-
however, brings with it very real prob- mented on subsequent drafts including
lems. Water quality, wastewater treat- Lester B. Smith Jr., Gary Clayton and
ment and refuse disposal are but a few Jeff Benoit.
of the problems coastal cities and
towns are now encountering. Foremost Special recognition is given to
among the immediate problems Denise Leonard who helped coordinate
attending coastal development is the and carry out much of the field work
susceptibility of roads, dwellings and in the Towns of Plymouth and Bourne.
infrastructure to damage or destruction Bill Taylor, Town Engineer of Sand-
caused by coastal storms. Areas subject wich, and members of the Massachu-.
to flooding and storm wave action, setts Department of Public Works
shoreline retreat, and shifting beach assisted with the land surveying.
and dune areas create situations that, if
ignored, can endanger not only finan- Russel Bramni was the designer.
cial investments, but human lives as
well. jean Mills of the Plymouth His-
torical Society, Russell Lovell, Jr., of
This publication is intended to the Sandwich Historical Society,
help the general public better under- Barbara Gill of East Sandwich, and
stand the natural hazards existing Broadsider newspaper contributed val-
along the shoreline. It is the first in a uable historical photographs and infor-
series of regional guidebooks to coastal mation.
hazards of the Massachusetts shoreline,
and describes the shoreline between
Sandy Neck, Barnstable and Manomet
Point, Plymouth. Your comments and

Publication of this document approved by
John Manton State Purchasing Agent. Each
copy costs $3.23.

How to Use This Guide Contents
This guidebook describes the coastal Chapt er Three discusses planning Evolution Of The Coast
hazards associated with the Cape Cod and management schemes necessary to Geological Past 4
Bay shoreline between Sandy Neck, minimize or eliminate coastal hazards. Coastal Forces: winds, waves, tides and storms -6
Barnstable and Manomnet Point, This chapter presents several alterna- Coastal Environments 9
Plymouth. Included are portions of t ives to accomodate development in Coastal Hazards
shoreline in the towns of Plymouth, otherwise hazardous areas.
Bourne, Sandwich, and Barnstable. Coastal Land Use 17
These hazards, which can result in Finally, the Appendix of this Coastal Engineering Structures 26
costly storm damage, include flooding, guidebook contains several items to Coatal Management
wave damage, shoreline retreat and the further aid the reader in dealing with Eitn osa aaeetFaeok__2
shifting of beach and dune areas. coastal hazards. A list of references and Planning forstalMaaemn Futraewr 28
selected readings is included as well as Conclusions 29
This guidebook is designed to sources of additional technical assis-
provide town boards, public officials tance or information. Appendices
and private citizens with a better References and Selected Readings 3
understanding of shoreline processes Glossary 32
and potential hazards resulting from Sources of Assistance 3
indiscriminate development along the Shoreline Change Maps 3
coast. The information contained in
this guidebook offers the basis for
establishing substantive long term
planning criteria, improved project
review, and the saving of money, prop -
erty and lives. The guidebook contains
three chapters and appendices.

Chapter One presents an overview
of the geology of the area, past and
present. Before future changes can be
adequately assessed, how the shoreline
was initially formed and what forces
continue to act upon it must first be
understood.

Chapter Two describes the hazards
associated with development activities
which do not adequately consider the
natural processes described in chapter
One. Improper placement of dwell-
ings, piers or inlets can create unneces-
sary and costly problems for the
taxpayer.

177

Geological Past
Most of the coastal upland bordering As the ocean formed, the edge of By the time the ice had retreated
southwestern Cape Cod Bay was left the continent slowly sank and layers of to this area, its front had taken the
much as it appears today by the sediment were deposited one on top of form of three vast lobes, referred to
retreating glaciers of the last great Ice another. Often deposition was fol- (from west to east) as the Buzzard's
Age. There is more to it than that, of lowed by erosion as the level of the sea Bay lobe, the Cape Cod Bay lobe and
course, for the surface materials overlie fluctuated. The top layer of sediment the Great South Channel lobe. The ice
ancient rocks, worn survivors of former was added about 15,000 years ago by front remained relatively stationary in
mountain ranges, now separated by the final retreat of the vast ice sheet this area releasing in bands large vol-
thousands of miles from their counter- that had once covered the northern umes of materials which had been
parts across the Atlantic Ocean which part of the continent as far south as carried by the ice to form glacial
began forming almost 200 million the present location of Long Island in moraines. The Sandwich moraine
years ago. New York. formed at the front of the Cape Cod
Bay glacial lobe when its rate of ad-
vance was essentially balanced by melt-
'~~~~~~~

.'~- ing. This moraine forms the high
"backbone" of the Cape, running east
,,,omt Po Cod through Sandwich and Barnstable.
The highest elevation on Cape Cod is
found on this moraine at Telegraph
Hill in Sandwich, which has an eleva-
tion of 295 feet above sea level.
The complex glacial history of
northern portions of this area is still
poorly understood. It is generally ac-
knowledged that the deposits found
here represent a region where two of
the great lobes of glacial ice, the
Buzzards Bay and Cape Cod Bay lobes,
met and shifted back and f orth.

1.Location map. T h e a rea cover ed i n this
Guidebook.

Following the period of the pebbles and cobbles forming'"ventri - are generally agreed upon: first, the
Sandwich moraine, the Cape Cod Bay facts" or wind faceted stones - ctom- land in this area has been gradually
lobe retreated a short distance further monly found in the surface soil today. flooded by the sea from the time it was
northward and again paused. The melt Finally, about 12,000 years ago, a freed of ice until the present; the sec-
waters formed a long, narrow lake with milder climate melted the permafrost ond, relative sea level is now rising at a
banks formed by the Sandwich and ended the cutting of stream val- rate of about one foot per century.
moraine on the south, the Cape Cod leys. The remaining buried ice blocks Later in the guide it will be demon-
Bay lobe on the north, the South melted, forming kettle holes and strated how important this rise in sea
Channel lobe on the east, and high leaving the landscape much as it level is in determining shoreline
land south of Plymouth on the west. appears today.* changes.
At one time the level of this lake
reached a height of 50 feet above pres-
ent sea level - a fact demonstrated by
lake delta deposits found at that
elevation on Scorton Neck in Sandwich
and in the Manomet area. Similar lake
deposits have been identified on
Spring Hill and Town Neck Hill in
Sandwich. This ancient lake - which
has been named Lake Shaler after the
geologist who first suggested its
existence - had, as its principal out-
let, Monument Valley, presently the
site of the Cape Cod Canal. As Lake
Shaler drained, it eroded Monument From that time until the present,
Valley and as a result, the lake level sea level has risen, submerging the
was lowered. However, final drainage deposits left by the ice. For geologists,
only took place when the ice front "sea level" means "relative sea level"
finally retreated north of the outer arm - the level of the sea with respect to
of Cape Cod. the level of the land at some particular
For several thousand years follow- place. It is often difficult to determine
ing the retreat of the glacial front from whether the sea is flooding the land
Cape Cod Bay, Cape Cod experienced because the sea is actually rising, or
a cold and windy "periglacial" (or because the land is sinking. There is no
near glacial) climate. The ground doubt that much of the rise in our area
remained "permafrost," that is, frozen has been caused by actual sea level rise
year - round so that surface water, un- due to the water released by melting
able to percolate into the soil as it does glacial ice, but there is strong evidence
today, flowed swiftly and cut stream that the sinking of the land is also a
valleys. Strong winds easily transported contributing factor. Despite the uncer-
the loose sediment, and the finer tainties of how much of the rise is con-
materials "sand blasted" the surface of tributed by each process, two things

2. Ice margin during the deposition of the Sandwich 3. The changing shoreline of Cape Cod: a) 12, 000
Moraine. years ago, b) 6, 000 years ago.
*From Robert N. Oldale, 1974, whose writings have
been freely used in this section.

Coastal Forces: Winds, s,

Winds Waves
Winds are very important to coastal When a wave reaches shallow water, it and backwash of water on the seaward
processes because they produce ocean breaks, generally at a depth approxi- face of the beach is called "swash.'
waves which contribute to the charac- mately equal to the wave height, Waves rarely come ashore exactly
teristics of the coastline. The size of though the actual point at which it parallel to the shoreline. Even when
the waves produced is dependent on breaks is dependent in large part on the wind is directly onshore variations
the wind's strength, duration, and the slope and topography of the bot- in the shape of the shoreline and near-
fetch which is the distance of open tom. After breaking, waves reform and shore topography cause waves to bend
water over which winds blow to build continue moving landwards eventually or refract as they approach the shore.
waves. Figure 6 shows that the direc- breaking for the first time on the Figure 8 is a diagram of the refraction
tion of maximum fetch for most of the beach face. Sometimes wave height pattern of a northeast swell approach-
guide area is toward the northeast, the and water depth are such that the ing the portion of coast covered in this
same direction from which blow the incoming waves break for the first time guidebook. This figure has been drawn
strongest onshore winds. directly on the beach face. The uprush for illustrative purposes from aerial

4. Changes in sea level along the Atlantic 6. Direction of maximum wave fetch in the Guide
Continental Shelf Area.
S. Mean Sea Level changes on the northern east
coast of the United States.
~~~~~~~~~i~~~~~~~~g~~~~~~~~E~~~~~~~~~~~~~~~~~~~~~~~~~f~! ~i~~

111811111 ~~~~~~~~~~:::~~

coast of the United States.

photographs and shows the distribu-
tion of wave energy along the
shoreline.i
Waves striking the coastline at an
angle cause a movement of water and lil-.' Vi ~ L
sediment along the shore in the direc-
tion of travel of the incoming waves.
The alongshore movement of sediment
is called "littoral drifting." The rate of 7
littoral drifting is dependent on wave
height and the angle of wave ap-
proach. As would be expected from
the direction of maximum wave fetch,
the dominant direction of littoral drift-
ing for this area is from Manomet
toward Sandy Neck. This is evident
from the buildup of sand on the
northern (updrift) sides of all groins in Tides
the area and the corresponding loss of
sand on the downdrift sides. These The major daily variations in water (perigee) coincidentally with a new
effects are discussed more fully in the level in Cape Cod Bay are due to astro- or full moon. At these times, the
fectine ditcousal orefine trhe
section on coastal engineering nomical tides. Astronomical tides are tidal range is extremely high due to
structures. the result of the gravitational pull of the added gravitational effect result-
.. . the moon and sun on the earth's ing from the moon's proximity to
.... : .. ...... ..oceans. Of the two, the effect of the the earth.
moon is much greater than that of the
.74. . :u..~ : ~ 44 sun. Between Sandy Neck and
Manomet Point, high and low tides
occur twice a day (approximately 50
minutes later each day), and they have
an average range of 9/2� feet.
�i~~ ~~;q~ --The changing positions of the
moon, sun and earth cause varying
'~?~ ranges of astronomical tides. Spring
--::.7~ '�-.'-,-~,.tides - those with high ranges-
occur near the time of the new and full
moon, when the moon, earth and sun
are all aligned. Neap tides, with low
tidal ranges, occur near the first and
last quarters of the moon. Perigean
spring tides appear twice a year, when
the moon is closest to the earth

7. Waves breaking at an angle to the coastline 8. The general wave refraction pattern for the Guide
produce littoral drifting. Area.

Storms produce dramatic changes
to the shoreline both because of the
flooding due to storm surges and
- . ~~because of the enormous energy of

.~~~~~~~~~ ds
.. .-..*. *. str ae...etw'yesosom
des, cause goe tha e enorus nld ofath

suhrcosofNew England.aehriae n
Thea greaest storm damage awong
.o winch. Englandutesshore oft lae tCod Boayth
not us lewyErnd duen hurricanes, bn

'" ~ ~~~~ ~~~~~~~rte to northeast ers. (or ricantes astrke

Astandreatme. These sormsginautefo
St'"'~ k~yhore~,~_'mds low pressure systems inorthi-

The ~~~~~~~~~~~~~~~~~~~~tides, arineendgentowaerwally ovrtecasta wnater off the es
level ch~~~~~~~~~~~~~~~~~~angsscacusedymteoolgia coasto h Urngitettshng sotherl
co~~~~~~~~~~~~~~~~~~~~~wnditos, which canost beverelydffcte syteaprhes e nln t
easoutern coast ofctn d rringa in
canreach greatest mamage ald
hei dutgust and Sfore tf Caei ay iori

re~~~~~~~~~~~~~~~~~~~~~~aslon arecle stomsurges.i isysanrmthem inotes tow lthe
otues a enersually ea sts cicaned nofth
cominoes wich eastersly (o no'acs the as
southern coast bycof anrew ong
The predato t storm dattme loing hs
hae sthweset storm results from the
phermsilow pressureswhich accompanyin-smultaneous moccurrnef north-ast
the sre sto r. Worthe coastronomicaoreasters and theeast

,twhide combinthe predwith storm upraes New thits

hangreach essive (and stoms r from amag e
hihS drn tormsan for thissuire msyses moving tenortheAtantchst

9s The ciding "stom surgtides arelindenracnt of wate northeast to the as
Storm changes caused ofte mtheoresltogical costofuthwest cUsnite Sutaines. Whnorth-

cnditionshore winds (r ted tosywin apprough New England. i
set-up''),vand the ise ofnthersea daragein
sunrface inpresponse ton loesruied atcolmois-rqetl areut from themaimecl
teighsedrn storms. Whnd larg atrooica eastrl gales andveritheNotAlantc spring
tieascombine withe "storm surges. a iisdwnfo the notideast.oh
hirmsugeaeofnthersut oflaoutwetdcuing andtained north-

9.Tecomincidiong of effetronoincaludiengen tideseasterlyecteds trak bof hraneos thahve passe
adssandonshore winds (refre o as"iduarea.Etrm flooding thrugh New occurred

hihsalodn nd storm damage.

Coastal Environments
In order to assess the role of winds,
waves, tides and storms on the shore-
line, imagine the coast as it would ap-
pear today without any of these forces.
As sea level rose, it would have slowly
submerged the glacial deposits. Valleys
would have been flooded, creating
coastal embayments such as Ellisville
Harbor. The shoreline southeast of
Scusset Beach would have had the
form of the boundary of the primary
(upland) deposits. The shoreline
north of Scusset Beach would have
had a similar form, but it would have
extended far seaward of the present
coast.
That the actual shoreline is quite
different from our hypothetical one, is
primarily due to the effect of waves. As
previously stated in the Coastal Forces
Section, waves generate a "littoral
drifting" from Manomet Point toward
Sandy Neck. This section of coast rep-
resents a distinct coastal processes unit:
sediment eroded from the exposed
A 'primary" glacial deposits of the
northwestern section is transported
south then east where it is deposited to
form the barrier beaches or "secondary
deposits" of the southeastern section.
The barrier beaches provide protected
landward estuarine areas where "ter-
tiary" salt marsh deposits form.
Waves, tides and winds, interacting
with the coast, produce a wide variety
of shoreline forms and coastal habitats
through the processes of sediment
removal, transportation and
deposition.

1I. Two characteristic northeast storm patterns. Low pressure systems draw air form the North Atlantic,
causing sustained high winds from the Northeast to blow over New England.
12. Coastal deposits in the Guide Area. [] Primary Deposits, Upland
* Secondary Deposits, Beaches and Dunes
I Tertiary Deposits, Marshes

IM iil... . IilSil,,-. .l..... -i :.

Primary Deposits
Perhaps the most striking of the pri- The loose glacial deposits scoured from from place to place. They depend on
mary deposits are the high coastal cliffs these cliffs are the major source of the the balance of many factors, chief
(or bluffs or banks, as they are also sediment which forms the offshore among which are the geological com-
called) which line much of the coast bars, beaches and dunes, the "second- position of the cliffs and the amount
from Manomet south to Sagamore ary" deposits. of wave energy that they receive.
Highlands. These cliffs are formed The rate of cliff erosion, and the
as waves, mostly storm waves, cut into types of materials supplied to shore
the hills left by the glaciers. systems by erosion vary considerably

13. The cliffs of Sagamore Highlands are typical of eroding primary deposits.

The complex geological history of
the mid-Plymouth area, where there
exist coastal cliffs, has produced de-
posits with a wide variety of charac-
teristics. Generally, the headland areas
- Manomet, State, Indian Hill and
Center Hill points - are composed of
unstratified glacial "till," which con-
sists of materials with a wide range of
sizes, varying from large boulders to
fine clay particles. In some areas till
deposits were left in place by the ice
without much further transportation
by streams or wind.
The cliffs composed of glacial till
are relatively resistant to wave attack in
part because their past erosion has left
a residual apron of boulders on the A comparison of shoreline posi-
shore in front cf them. Too massive tions on Figure 15 indicates that
to be moved by waves, these boulders between 1866 and 1956, the shoreline
break up much of the force of of the embayment south of Stage Point
incoming surf, and consequently the retreated a maximum of about 125
partially protected cliffs have not feet. Between 1916 and 1956, rapid
eroded as fast as adjacent cliffs com- erosion averaging about 450 feet
posed of fine grained material. As a occurred south from Ellisville Harbor,
result, Manomet, Stage, Indian Hill around Lookout Point to Peaked Cliff.
and Center Hill points have undergone It should be emphasized that cliff
relatively little erosion. In contrast the erosion is due chiefly to sea level rise
areas between the headlands have and wave action. However, the result-
eroded rapidly. ing cliff forms are also modified by
several other mechanisms. Strong on-
?M : , , shore winds in dry weather move finer
sediments both up and down the cliff
face. Frost action, the alternate freez-
ing and thawing of water-soaked sedi-
ments, loosens grains which then may
fall or blow away more easily. Drainage,
from groundwater and surface water
runoff may cause considerable localized
erosion, as may be seen in the cliffs
southwest of Stage Point and near
Indian Hill.

14. Center Hill Point. Glacial till has eroded from the 15. Rapid erosion of the shoreline at Sagamore 16. Near Stage Point. An example of localized
headland. Rubble in the middleground is slowing Highlands 1866-1956. erosion caused by groundwater runoff
further erosion of the cliff and is producing
secondary deposition.

Secondary Deposits
Cliff erosion tends to be periodic and The protection is not perfect for a extend along the entire shore from
local, rather than constant. Of course number of reasons, important among Manomet to Sandy Neck. These bars
very severe storms such as the which are continuing sea level rise, and serve to protect the beach during
"Blizzard of 1978," cause widespread sediment loss offshore and alongshore. storms by causing the high waves to
cutting of the cliff face; but in general Yet the movements of sediment serve break offshore and lose much of their
the amount of erosion depends upon protective functions also. The onshore destructive energy. The waves which
the degree of protection afforded the and offshore movement of sand adjusts remain, or reform, continue on to the
cliffs by the adjacent beaches and off- the form of the beach to the conditions beach; but the foreshore has been
shore sand bars. The cliffs themselves, of the sea. When waves are low and far changed to a gently sloping plane
through their erosion, provide the apart and storms are few - as during and the remaining storm waves
materials to form the beaches and bars the summer - the beach develops a break over its broad surface. Only
which then protect them from further steep foreshore and wide backshore. when the tide level is very high will
erosion. Such "feedback" systems, During the stormy periods, how- storm waves reach the cliff and cut a
producing - or rather approaching - ever, high steep waves cut into the nearly vertical scarp into the base of
stability, are common in nature. beach, carrying sand offshore where it the cliff, causing it to slump down
is deposited to form elongated subma- under its own weight. When the storm
rine sand bars. With the exception of waves subside, they are replaced by
Manomet Point and some of the other longer, lower waves which transport
headland areas, offshore sand bars back to the beach some of the sand
which had been stored in the bar.

17. Cedarville Landing. The cliff was undercut by the 19. Beach Form. a) Pre-storm conditions b) Storm conditions c) Post-storm conditions.
waters of the 1978 blizzard.
18. Mated'al from eroding cliffs build beaches and
bars that slow further erosion.

Sand moving along the shore as ., 4 .
littoral drift performs other protective h 4 t&~f$ '
functions. By removing sediment from
some stretches and adding it to others, V
waves can model the shoreline into
smooth forms which ''face" the direc- ~ vYh
tion from which the waves arrive. Since ~
the amount of sediment moved along t�~ePeo 4#2t sz~
the shore decreases as the direction of
wave attack becomes more directly on-
shore, the shoreline develops an in-A
creasingly stable form. Again the feed- 2ttk %$
back mechanism: the shoreline changes
in such a way as to decrease the tt~.~&#v~t
amount of change.itAgo4AfQN
There are some good examples of t h ; 4WN\ A X 4
this process in this area. The shoreline Mh,
between Cape Cod Canal to Sandy
Neck faces the direction of maximum
wave fetch and has a stable form.
However the coastal embayment south ~44 A<
of Stage Point does not face the maxi- $~$Q
mum fetch direction. The zone of
erosion south of Stage Point was men- k� '*
tioned earlier. At a point about haif-vttLs4 .:mAW
way frm Stae Poit to ndianBrookWaves move Sand along the coast, coast, are Ellisville Beach; Sagamore
wyfoStage erosiont stopsdiand Bromtapokn creating shorelines with increasingly Beach; Town, Spninghill and East
sothe ersotops andia frook that shoreint stable forms. Stability is always ap - Sandwich Beaches; and Sandy Neck -
souitht Indianroo the asmuhoasefintee proached, but because sea level is ris- a string of four barrier beaches extend-
buitween 86awad 1956 ahse mchangs fiteting, it is never achieved. In places, the ing downdrift from the northwest to
aretwe-iectng 186ad15Thes charlngestwr beaches which are formed by these the southeast, each larger than its pre-
the direction of maximum fetch. processes extend out past what would decessor, each extending further off-
otherwise be the shoreline. The shore. The source of sand for them all
Similarly, south of Lookout Point beaches are called barrier beaches, is the eroding cliff line north to
to Peaked Cliff rapid erosion occurred because they act as barriers against Manomet.
between 1916 and 1956. However, open sea waves, thus protecting salt Barrier beaches are extremely
southward from Peaked Cliff, the marshes, lagoons and quiet bays be- dynamic features, changing continually
amount of erosion decreased, until, at tween themselves and the upland. in response to the forces acting on
Scusset Beach, erosion and accretion Small barrier beaches connect head- them, including sea level rise. Figure
were about equal. Again, by means of lands at Center Hill Pond and Ship's 20 illustrates the lateral downdrift
sediment exchange, a shoreline is re- Pond. The largest ones, which together growth of Sandy Neck in response to
orienting toward a more stable form. account for more than half of the outer wave produced littoral drifting. Waves

20. The evolution of/Sandy Neck.
1Sand
- lnr ntridlMarh
UUpl.d U High Marh

also assist barrier beach growth and
their landward shift in response to sea-
level rise - by means of overwash.
During overwash, storm waves carry
sediment across the lower portions of
the barriers and deposit it on the inner Barrier beaches also change in source, they also provide storm protec-
side. response to the action of tides. Tidal tion to the inner shore.
Much of the bulk and protective inlets through barrier beaches, such as It is this inner shore, the shore of
function of barrier beaches is provided those at Ellisville Sandwich and Scorton the uplands, which makes up most of
by dunes, which are formed by sand Harbors, and at the Cape Cod Canal, the actual length of the shoreline. It
moved landward from the beach by which is a man-made inlet, stay winds in around valleys and out
onshore winds. Above the spring high open as the result of the tidal currents around hills, and because its seaward
tide line this sand is "caught" by which scour their channels. Deltas tend slope is relatively steep, the retreat of
beach grass and other salt-resistant veg- to form inside the inlets (flood tidal the inner shoreline due to rising sea
etation. The vegetation grows upward deltas) and outside of them (ebb tidal level is very slow. It is protected from
through the accumulating sand causing deltas). the sea by the bars, beaches and dunes
the dune crest to reach elevations well of the barrier beaches, and by the
above the highest waves. Dunes pro- Tertiary Deposits marshes and flats which lie behind
vide storm wave and flood protection The tertiary deposits - those carried them. It is at this point that a true
not only by means of their elevation, inside the barriers by winds, waves and terrestrial environment begins.
but also because they store sediment tides - form the substrate for the
which is returned to the beach system growth of salt marsh vegetation which
when storm waves have eroded the thrives in protected intertidal areas.
beach to-the point that the dunes are Not only do the marshes form an
* cut, oi "scarped" by wave action. important biologically productive re-

21. Landward shift of a barrier beach through 22. A scarped dune.
ovenvash.

'---'

~- - -Xym-5MCSp1.V

?: v:::? ,/iaTe o.
. 1952-55 sho:eline

23. a) Ellisville Inlet, 1980. b) Shoreline changes at Elli/ville Inlet. Accretion
24. a) Sandwich Inlet, 1980. b) Shoreline changes at Sandwich Inlet. Erosion
25. a) Scorton Inlet, 1980. b) Shoreline changes at Scorton Inlet.
26. a) The Cape Cod Bay entrance to the Cape Cod b) Shoreline changes at the canal entrance.
Canal in 1950.

Coastal Land Use
The history of this coastal area reflects
a number of different uses by man,
ranging from cattle grazing to off-road
vehicle recreation. Each of these uses
reflects the differing values of the in-
habitants, as well as their degree of
knowledge of the natural systems.
Indians, the first human inhabi-
tants of our coast, left little evidence of
their presence and seem to have lived
compatibly with the coast.
The first white settlers established
Plymouth in 1620. Sustained by farm-
ing and fishing, these early residents
utilized the abundant resources of the
land and sea. The virgin forests pro-
vided the lumber for building homes
and ships. Clay discovered in the Cliffs roof homes and utilized as insulation These early settlers were wary of
at Manomet Point and Ship Pond was for their homes as well as fertilizer for situating their homes and structures
mined for pottery. their crops. The sheltered creeks and too close to the coast. They had ob-
In 1624, ten men received permis- inlets served as harbors and navigation served tidal flooding along the coast
sion from the court in Plymouth to channels for coastal trading. Disputes during storms.
venture south to take advantage of the often erupted between the farmers and The town of Sandwich prospered
great salt marshes at Sandwich and the fishermen with respect to the use during the 1800's. In 1825 the famous
Barnstable for grazing animals. Follow- of the marsh areas. The farmers valued Sandwich Glass Factory was established
ing an old Indian trail, they settled in the land for farming and grazing adjacent to Mill Creek, which was used
an area now known as Sandwich. The cattle, but the fishermen valued it for to transport goods in and out through
vast marshes provided abundant feed eels and shellfish as well as access to Sandwich Inlet.
for their cattle. Salt marsh grass and fishing grounds in Cape Cod Bay. By the 1830's small settlements
seaweed were also gathered for thatch- such as Ellisville dotted the coastline.

27. Fishing shacks and workboats near Sandwich, ca.
1900-1910.

1 7

These tiny communities had developed Massachusetts, which along with New An important event promoting
a prosperous coastal trade. Ellisville Jersey, led the nation in cranberry pro- the development of the coastal region
Harbor became an outlet for trading of duction around the turn of the was the completion of the railroad in
timber from the surrounding forests century. 1848. Railroad beds were constructed
and "bog iron" from the numerous In 1914 the building of the Cape across the great marshes, cutting off
nearby wetlands. These were trans- Cod Canal was completed. A wide daily tidal flushing and flow of
ported to Plymouth Center and Boston man-made waterway was cut through nutrients to the coastal waters. The
via small coastal packets. Scusset marsh and the dredged mate- railroad provided a means for trans-
The bogs were eventually depleted rial was deposited in the adjacent porting goods which eventually phased
as a source of iron by the 1800's but marsh. jetties were constructed at the out coastal trading by boat. The rail-
another resource - cranberries - entrance to the canal to inhibit shoal- road also provided Bostonians with
gained in importance. Plymouth i ng by sand transported alongshore by convenient access to the scenic coastal
became a major producer in littoral drifting, areas of Cape Cod.

28. The Sandwich Glass Works, ca. 1910.

In the early 1900's shorefront ment trends of the Guide Area from settlement patterns and built in areas
development increased as these areas prior to 1865 to 1977. that would have been considered un-
developed into resorts, a trend acceler- Unlike the early coastwise resi- suitable by the early settlers. By the
ated by the rising popularity of the dents, summer dwellers and vacation- 1950's the edges of the cliffs and dunes
automobile. Finally local, state and ers often unfamiliar with the natural had become such valuable real estate
federal development of public access processes of the coast disregarded early that most of these areas had been de-
areas further increased popularity of ~ ..~~~veloped. This resulted in problems that
beaches for recreation. Numerous prviu generations hdnot
~~W>�

pedestrian pathways now weave across ecutrd
the dunes at Scusset, Sagamore and :i ! '? ,. '
Springhill Beaches. Parking lots and ~.......
roads to waterfront homes also occupy
areas of beach and dune areas. Sandy
Neck became a popular recreational
area for off-road vehicles. An intricate
system of roads developed through the
dunes along the entire length of Sandy
Neck. Figure 35 illustrates the develop-

29, Oc eanfront cottages at Sagamore Beah, ca. 1916. 30. The Beach Road Bridge in 1911.
duses on Ea t Sandwich Beach are on the
horizon,

35. Development trends of the Guide Area,

Development Prior to 1865

"mi Development from 1865 to 1953
Development from 1953 to 1977
1 2 3
O~~~ I I~~~~~~~~~~ , IMiles
SOURCE: USGS

North

='_k
Scorln .' '7, H

to structures within its reach. The
highest tide reported since 1851
washed a wall of water 4' high over
the lowlands. Overwash of the beach
Coastal Flooding occurred in three places between
Coastal Flooding Sandwich and Springhill. Many areas
Shortly after their arrival to the New What these early inhabitants were ex- of the railroad were destroyed where it
World the early white settlers were periencing was their first hurricane. crossed the marsh. The main street
beset by the disaster of coastal flood- This early encounter perhaps taught in Sandwich was inundated to a
ing. William Bradford accounts in them of the effects of a storm on coast- depth of 3' as 60-80 M.P.H. winds
1635 of, al areas and the resulting flooding that whipped the coast. More recently
"a might storm of wind and accompanies these events. the storm of December 29, 1959
rain ... it came with a violence, to Similar storms were to follow. In caused major flooding in Barnstable
the amazement of many ... The 1722 a northeaster struck the coast of and Sandwich. Tidal flood water en-
signs and marks of it will remain for New England causing the water level gulfed all coastal areas and waves bat-
100 years in these parts where it was to rise 15' above normal. tered man-made seawalls and other
sorest." (Wood, 1976) Severe flooding occurred in structures. The great "Blizzard of 78"
The storm described by another, Sandwich during the storm of 1851 a nor'easter not soon to be forgotten,
". .. blew down houses and vessels when a gale pushed tide water up to battered the coast with 92 M.P.H.
were lost at sea ... It caused the flood the Sandwich Glass Factory 25 winds. The severe flooding and wave
sea to swell in some places to the years after it was established, and to damage to coastal areas caused loss of
southward of Plymouth to 20' . . . the north Minot's Lighthouse was par- life, property, and evacuation of
It began in the southeast ... the tially destroyed. 11,000 persons in New England.
greates force of it at Plymouth con- The Portland Gale of 1898, the Figure 40 summarizes characteristics
tinuing for 5 to 6 hours." (Wood, most damaging storm ever to hit of the major storms affecting
1976). Sandwich, caused extreme destruction Cape Cod.

36. Damage from the Portland Gale of 1898 in Sandwich. The railroad bed in the mid ground was totally 3 7. Sandwich houses damaged by the Gale.
wreckedand the house in the foreground was knocked off its foundation.

g i i W ! l ! , ; m S m

..... it UI~ is ~? i]? ': i'i~ ~~~ .....

38. Severe erosion near Ship2s Pond caused by the 1978 blizzard.
39. A cliff side house severely undercut by wavae action :from the blizzard,

Figure 40 Table of Historic

August 15, 1635 Water level rose 20' A hurricane, it was described by William Bradford
as the first recorded storm in New England. It coin-
cided with the perigean spring tide.

February 24, 1722 Water level rose 15 '4" above low The storm was a northeaster.
water

January 1, 1778 It was called the "Magee Storm" and had the
highest tide reported in fifty years. The storm's
rising water pushed ice floes into the marshes and
destroyed the marsh hay stock structures.

April 17, 1851 Water level was 14 '9" above mean Called "Minot's Gale", it produced extensive
low water coastal flooding. In Sandwich, the tide waters
reached the Glass Works.

April 12-24, 1888 The "Blizzard of 88" was a northeaster with
extremely high winds.

November 26, 1898 The water level rose 14' above The "Portland Gale" was the most destructive
mean low water storm in the history of Sandwich. Its 60-80mph
winds pushed a wall of water four feet high over
the marshes and destroyed parts of the dike and
railroad bed. Main and River Streets in Sandwich
were flooded. The passenger ship The Portland was
lost off the coast of Cape Cod.

December 26, 1909 At Barnstable, the water rose 5' The storm was a northeaster.
above mean low water.
March 3-4, 1927 A perigean spring tide, it coincided with onshore
winds of 21-49 mph.

September, 1938 The water level rose 5' above This devastating hurricane took 187 lives and
mean high water caused record flooding throughout New England.
Winds of 186 mph were recorded.

February, 1940 This northeaster undermined beach front homes
and caused shoaling in Sandwich Harbor.

Storms affecting the Guide Area

April 21, 1940 The water level rose 13 '8" above This storm combined 31 hours of 30 + mph winds
mean high water with a perigean spring tide.

September 14-15, 1944 This hurricane had 80-104 mph winds.
November 28-30, 1945 The water level rose 12 '5" above This storm, like the storm of April 21, 1940, had
mean low water sustained onshore winds with a perigean spring
tide. There was much damage to shorefront
property and erosion of as much as 15'

April 31-September 1, 1954 Hurricane Carol's 100 + mph winds caused much
damage to the south shore.

September 11, 1954 Hurricane Edna, closely following Carol, had winds
of 100 + mph and caused additional damage to the
South Shore.

December 29, 1959 The water level rose 15' above This storm had ENE winds of 25 mph with strong
mean low tide and in Boston was gale forces. Its tidal flood waters engulfed all
21/2' above normal coastal areas, battering sea walls and causing flood-
ing to within 50 yards of Main Street in Barnstable.
13 houses were inundated there.

September 12-13, 1960 Hurricane Donna.

November 28, 1967 This storm was another example of a perigean
spring tide coinciding with sustained onshore
winds.

January 8-9, 1978 This storm occurred on a higher than normal tide
and caused flooding and severe coastal erosion.

February 6-7, 1978 The "Blizzard of 78" was a northeaster with record
snowfall, flooding and erosion. An estimated total
of 180 million dollars of damage in the most
destructive storm of recent times.

E 5 5 F -Gus-B y 7 - w _ _ 7 _

Coastal Engineering Structures
Man's response to the loss or potential
loss of property built within the reach
of coastal processes has been the de-
velopment of various coastal engineer-
ing structures. These include groins,
jetties, seawalls, revetments and bulk-
heads. Each is designed to act either as
a barrier to trap sediment being trans-
ported alongshore, or as a wall to pro-
tect cliffs and dunes from destructive
wave action.
Examples of typical coastal engi-
neering structures will be discussed in
the following sections. A complete in- ing sand to be deposited updrift of the jetty must reach seaward to deep water
ventory of structures, including photo- groin and widening the beach. When beyond the littoral zone. As a result,
graphs, was completed for the stretch the updrift side of the groins is filled, sand nourishment to beaches down-
of shoreline discussed in this guide- sand may move around the groin, often drift on the inlet is severely restricted
book. The inventory is available for
b o ok. The inventory is available for into deeper water where it is lost from or cut off altogether causing starvation
review or use at the Coastal Zone the littoral drift. and rapid erosion.
Management Office.
Management Office. Jetties The long jetty on the northwest
Groins Jetties are elongate structures similar to side of the Cape Cod Canal traps much
Groins are elongate structures usually groins except that they are built at the of the sand which reaches it, causing
oriented perpendicular to the shoreline seaward side of a coastal inlet or severe erosion of the beaches of the
and commonly constructed of rock, harbor. Their purpose is two-fold: to canal. The small inlets such as Ellisville,
concrete, wood or different combina- stabilize the inlet and to prevent shoal- Sandwich and Scorton Harbors have
tions of the three. Groins are designed ing of the inlet by sand carried by lit- short jetties which do not completely
to alter the shoreline by disrupting and total drifting. To completely halt trans- disrupt littoral sand transport and
slowing littoral drifting, thereby caus- port of sand into the inlet, the updrift sand can naturally bypass the inlet.

41. A groin. Littoral drifting is from right to left. 42. A groin field on Sandy Neck near Beach Point.

Terracing
Another method of coastal bank stabi-
lization is the terracing and planting of
Seawalls, Bulkheads and Revetments the bank. The aim of this method is to
The most common structures found sand particularly at their base. Acceler- prevent loss through slumping and
along the shoreline are seawalls, revet- ated scour is commonly observed on gullying. However, it cannot prevent
ments and bulkheads. These structures the ends of the structures. Over- wave cut erosion of a bank. Cliff-
are placed on or behind the beach in topping waves may scour away the terracing can give the cliff face a stair-
an orientation parallel to the shoreline. earth backing these structures, leading case relief by the construction of a
While distinctions between these struc- to their premature failure. A more series of wood or steel retaining walls.
tures are not always clear, they are long term effect is the reduction of These reduce the speed of rain water
designed to prevent erosion by wave sediment supply to the beach. running down the cliff face, thereby
attack. Without cliff and dune erosion the holding the cliff sediment in place.
The adverse impacts of these beaches are not provided nourishment This can also be achieved by planting
structures arise from their rigidity. and cannot fully replenish losses from vegetation, usually grass and shrub-
Beaches naturally absorb wave energy. storms or longshore drifting. bery, whose roots systems bind the
However, these rigid structures reflect sediment in place. Thorny shrubbery
incoming waves, causing turbulence or poison ivy can be used to discourage
which scours and removes the beach pedestrian traffic on the banks.

43. A typicalseawal construction. 45. A wooden bulkhead. 46. Cliffterracing.
44. A stone revetment.

"7~~~~~~~~~A

:Existing Coastal Management Framework
Until the 1960's, engineering struc- damage prevention and flood control. east of the canal. Lesser, but still
tures were perceived as the optimum A "Guide to the Coastal Wetlands significant effects will result from the
solution to coastal hazards. With in- Regulations" is available to assist con- existing seawalls, harbor jetties, and
creased recognition of the natural pro- servations commissions and applicants groins throughout the area. In
cesses governing coastal change came in interpreting and applying these planning for the future the protective
public pressure to preserve the features regulations. The appendix provides characteristics of coastal features can be
which provide the natural protection of information on obtaining additional best preserved by:
the coast. Local conservation commis- sources of assistance. a) not adding to existing
sions were established to review pro- disturbances, and
posed alterations of coastal systems. Planning for the Future b) removing or minimizing
The Massachusetts Wetland Pro- An adequate coastal management pro- disturbances.
tection Act of 1972 provided these con- gram should include 1) planning for Disturbances to the supply of pri-
servation commissions with an impor- future development based on existing mary coastal sediment include the
tant tool to further protect coastal areas knowledge of coastal systems, and 2) a building of coastal engineering struc-
"significant to the interests of storm program of research and education to tures at the base of coastal cliffs. The
damage prevention and flood control." increase knowledge of those systems. placement of buildings should be
During the same year Congress passed An introduction to the existing knowl- planned with recognition of the natu-
the Coastal Zone Management Act edge of the coast from Manomet Point ral cliff retreat rate. A reasonable "set-
which eventually made available to the to Sandy Neck is provided in this back" distance may be derived by
Commonwealth funds for the estab- guidebook. Future changes may be reference to the shoreline change maps
lishment of a state Coastal Zone Man- approximated from past changes, ex- (see Appendix) and the desired period
agement (CZM) Program. Working cept where processes have been altered between movement of the building.
together with the CZM Program, the by engineering structures or other Care should be taken to provide for a
Department of Environmental Quality man-made alterations. The major man- sufficient area inland from such build-
Engineering in 1978 provided the con- made obstacle to sediment transporta- ings to accomodate movings. Efforts
servation commissions with coastal wet- tion is the Cape Cod Canal and its should be made to encourage town
lands regulations. The regulations jetties, which (unless corrective action and state funding or tax benefits to
identify the particular characteristics of is taken) can be expected to continue help defray the expense of such moves.
coastal wetlands which should be pro- producing accretion of Scusset Beach Disturbances to the transport of
tected because they provide storm and erosion of the Sandwich shoreline coastal sediment and to the features

formed by deposition of such sedi- verse effects when possible, and by not It is clear that most historical and pres-
ment, include the jetties and groins repairing or replacing them when they ent day coastal hazards are in reality
mentioned above as well as other coast- are damaged or destroyed. Periodic natural processes which adversely affect
al engineering structures such as sea- beach renourishment with suitable man because of improper development
walls and breakwaters. Adding to such sediment may in some cases lessen the of coastal areas. In an attempt to
disturbances would include increasing adverse effects of such structures. In reduce these hazards man has built
the size of existing structures as well as the barrier areas, existing buildings, coastal engineering structures which
adding new ones. Any further con- once destroyed, should not be rebuilt. have in many areas diminished or
struction of buildings on the barrier Disturbances to vegetation may be re- destroyed the coast's natural defensive
beaches would disturb their protective duced by use of appropriately designed system. These structures have had a
characteristics. walk-ways for pedestrians and by limit- compounding negative effect by
Methods of improving currently ing access to off-road vehicles. Snow- creating an illusion of security which
disturbed coastal cliff areas include the fences can temporarily stabilize dis- has promoted further coastal develop-
revegetation of the cliff face and the turbed dune areas while revegetation ment. The best way to be spared of the
use of light, removable steps on the efforts are underway. Revegetation of "hazards" is to avoid developing in
cliff face. Disturbances due to coastal disturbed marsh areas has also been areas which are subject to predictable
engineering structures may be reduced successful. change due to coastal forces and
by modifying them to reduce their ad- processes.

References and Selected Readings

Bascom, W., 1964. Waves and Beaches, Doubleday and Co., Inc. N.Y.

Boston Herald American, 1959 Wed., Dec. 30

Bird, E.C.F., 1969. Coasts, M.I.T. Press, Cambridge, MA

Cape CodIndependent, Sandwich, Cape Cod Scrapbook, Dec. 12, 1973

Coastal Resources Center, Rhode Island Barrier Beaches, University of Rhode Island, Marine Technical Report #4

Department of Environmental Quality Engineering, 1978, A Guide to the Coastal Wetlands Regulations, available
from Mass. Cooperative Extension Service, Bulletin Center, Cottage A, Thatcher Way, Univ. of Mass., Amherst, MA
01003

Dolan, R., 1972. Beach Erosion and Beach Nourishment, Cape Hatteras, North Carolina, U.S. Department of the
Interior, National Park Service, Dune Stabilization Study #5

Ellis, E.C., 1973, Reminiscence of Ellisville

Earson, R.H., 1977. The Cape Cod Canal, Wesleyan Univ. Press

Giese, G.S. and Smith, L.B., Jr., 1980. "Coastal Wetland Regulations Based on Physical Coastal Processes," in
Resource Allocation issues in the Coastal Environment, Proceedings of the Fifth Annual Conference of the Coastal
Society. pp. 217-225

Hansen, D.V., 1977. Circulation, N.Y. Sea Grant Institute

Hicks, S.D., 1972. Vertical Crustal Movements form Sea Level Measurements along the East Coast of the United
States, Univ. of Geophysical Research, Vol. 77, No. 30, p. 5930-5934.

Humphries, S.M. and Benoit, J.R., 1980. Barrier Beach Protection In Massachusetts Proceedings of Coastal Zone 80.
pp. 1809-1829.

Ketchum, B. 1972. The Water's Edge: Critical Problems of the Coastal Zone, M.I.T. Press, Cambridge, MA

King, C.A.M., 1972. Beaches and Coasts, Edward Arnold Publishing Ltd., London
King, Storey, 1974. Use of Economic-Environmental Input-Output Analysis for Coastal Planning with Illustration for the
Cape Cod Region, Water Resources Research Center, Univ. of Mass., Amherst, MA

Komar, P., 1976. Beach Processes and Sedimentation, Prentice-Hall Publishing Co.
Leatherman, S.P., 1979. Barrier Island Handbook, National Park Service
Massachusetts Water Resources Commission, 1963. Coastal Flooding in Barnstable County
New England River Basins Commission, 1976. The Ocean's Reach, Digest of a workshop on identifying coastal flood
hazard areas and associated risk zones

Oldale, R.N., 1974. Geologic map of the Hyannis Quadrangle, Barnstable County, Massachusetts. Map GQ-1158,
U.S. Geological Survey, Reston, VA

Oldale, R.N., 1975. Geologic map of the Sandwich Quadrangle, Barnstable County, Cape Cod, Massachusetts. Map
GQ-1222, U.S. Geological Survey, Reston VA

Peck, E.E. and Leonard, D.A., 1980. Coastal Engineering Structures of Southeast Massachusetts Bay, Manomet to
Sandy Neck, Massachusetts, Office of Coastal Zone Management

Redfield, A.C., 1972. "Development of a New England Salt Marsh," from EcologicalMonographs, Vol. 42, No. 2,
pp. 201-237

Strahler, A.N., 1976. A Geologist's View of Cape Cod, The Natural History Press, N.Y.

U.S. Army Corps of Engineers, 1959. Shore Between Pemberton Point and Cape Cod Canal, Mass., Beach Erosion
Control Study, House document No. 272/86/Z

U.S. Army Corps of Engineers, 1971. Shore Protection Guidelines, National Shoreline Study

U.S. Army Corps of Engineers, 1977. Beach Changes Caused by the Atlantic Coast Storm of 17 Dec. 1970, Coastal
Engineering Research Center, Technical paper no. 77-1

U.S. Army Corps of Engineers, 1978. Massachusetts Coastal Study

U.S. Dept. of the Interior, Geological History of Cape Cod., Mass., Geological Survey

Yasso, W.E., Hartman, E.M., Jr., Beach Forms and Coastal Processes, N.Y. Sea Grant Institute, N.Y. 1976

Wood, F.J., 1976. The Strategic Role of Perigean Spring Tides, U.S. Dept. of Commerce

Woodworth, J.B. Wigglesworth, E., 1934. Geography and Geology of the Region including Cape Cod, the
Elizabeth Islands, Nantucket, Martha's Vineyard, No Mans Land and Block Island, Memoirs of the Museum of
Comparative Zoology, Harvard College, Vol. 62

Glossary
Accretion - The gradual addition of new land by the deposition of sediment carried by wave action.

Backshore - Upper shore zone, beyond the reach of ordinary waves and tides.

Barrier Beaches - A narrow low-lying strip of land generally consisting of coastal beaches and coastal dunes extending
roughly parallel to the trend of the coast. It is separated from the mainland by a narrow body of fresh, brackish or
saline water or a marsh system. A barrier beach may be joined to the mainland at one or both ends.

CoastalBank - The seaward face or side of any elevated landform, other than a coastal dune, which lies on the
landward edge of a coastal beach or wetland.

Downdrift - The direction of predominant movement of littoral materials.

Erosion - The gradual wearing away of land through wind and wave action or runoff from the bank.

Embayment - An indentation in a shoreline forming an open bay.

Fetch - The continuous area of water over which sustained winds blow.

Foreshore - The lower shore zone, between ordinary low and high tide ranges.

Glacial Till - Unsorted sediment carried or deposited by a glacier.

Groin - A shore protection structure constructed perpendicular to the beach to trap sand being transported in the
longshore current.

Groundwater - Water below ground level in the zone of saturation.

Headland - Glacial or preglacial landforms which project into the sea.

Littoral Drifting - Movement of sediment, including sand and gravel, along the 'coast caused by waves and currents.

Moraine - Ridges or mounds of material deposited at the margins of retreating glaciers.

Offshore Bar - An accumulation of sand in the form of a ridge, built at some distance from shore under water
resulting chiefly from wave action.

Onshore Wind - A wind blowing landward over the coastal area.

Overwash - The transport and deposition of water and material over and through a dune system during periods of
storm elevated water levels.

Periglacial - Refers to areas, conditions, processes, and deposits adjacent to the margin of a glacier.

Permafrost - Permanently frozen ground.

Seawalls - Man-made wall or structure built parallel to the shore.

Sediment - Solid material, both mineral and organic, that is either in suspension, is being transported, or has been
moved from its site of origin by air, water, or ice and has come to rest on the earth's surface either above or below sea
level.

Storm Surge - A local rise in sea level along the coast due to the stress of high winds and reduced atmospheric
pressure.

Swash - Rush of water up the beach face following the breaking of a wave.

Tidal Inlet - An opening maintained by tidal flow which connects a bay or lagoon with a larger body of water.

Tidal Range - The vertical difference between the level of water at high tide and low tide.

Source of Assistance Shoreline Change Maps

Local

Conservation Commission Coastal Zone Management has, in the
Planning Board course of preparing this guide pro-
Building Inspector 41duced a set of maps that delineate the
Natural Resource Officer shoreline changes of the Study Area.
Overlain on appropriate USGS
Regional 1:25,000 scale orthophotograph* sheets
are delineations of historic shorelines
Regional Planning Authority dating from 1899 to 1977. Diazo prints
County Extension Service of these maps are available from CZM
Sea Grant Programs for those interested.
The historic positions were com-
State piled using maps, charts and aerial
photographs supplied by the National
Department of Environmental Quality Engineering - Wetlands Division Ocean Survey. Digital Graphics Inc. of
Department of Environmental Management - Wetlands Restrictions Rockville, Maryland processed the
Program, Natural Heritage Program material. jet Barely and Peter Gibson
Coastal Zone Management of National Ocean Survey provided
Department of Public Works - Photogrammetry Section additional technical assistance.
FEMA/ State Assistance Flood Mitigation Program The maps give a reliable determi-
nation of how the shoreline has
Federal changed in the past. From this infor-
mation general shoreline change trends
Federal Emergency Management Agency can be identified and applied to future
U.S. Army Corps of Engineers changes. It is recommended that these
National Ocean Survey maps be used when planning, design-
Soil Conservation Service ing or reviewing projects in the Guide
U.S. Geological Survey areas.

Other organizations which provide advice on coastal hazards

Several universities, non-profit research organizations, and private consultants in
S.E. Massachusetts provide site-specific information on coastal processes and
hazards. Information concerning these organizations may be obtained from the
CZ M O f f i c e . ~~~~~~~~~~~~~~*Orthophoto maps combine a surveyed
coordinate grid system with the detail
of aerial photographs. At the scale of
1:25,000, one inch equals 2,083 feet.

MsJoan McElroy 22, 23,I24, 25, 39

Ms Barbara Gill, (Collection) 27, 28, 30, 32,33,
Mr Ben Harrison 18
Mr Stan Humphries 38
S ~ ~ ~ ( 7.

; f :~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~I

Kelsey Aerial Photo 34, 42
Mr Eugene Peck 13, 14, 16, 48, 49, 50, 51

Sandwich Historical Commission 26, 29, 31, 36, 37
~~~~~~~~~~~~~~~~~~~~~~~-a''Mr Les Smith 17
f aa a''aa,,a,. 0 at "", a ,a iSA Xa~aafa; ,aN _.,,

a- aA - f a

;" 4' (a " "'""a"" "!'a" <""i ' aa} ,,ta

0~~~~ at -a"/jaa-(-a 0 ,'aa ;a ��'a, 94

: , L,, fi; D'V0,0i ' S " '>a-~a a"
Photographic Sources "a " a
Ms Joan McElroy 22, 23, 24, 25, 39

Ms. Barbara Gill, (Collection) 27, 28, 30, 32,33,

Mr. Ben Harrison 18
Mr Stan Humphries 38

Kelsey Aerial Photo 34, 42
Mr. Eugene Peck 13, 14, 16, 48, 49, 50, 51
Sandwich Historical Commission 26, 29, 31, 36, 37

Mr. Les Smith 17