HomeMy WebLinkAboutLocal Erosion Management Plan Draft Aug 95 I
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TO WN OF SO UTHOLD
Southold, New York
Prepared for:
Town of Somhold
Town Hall
Southold, New York 11971
Prepared by:
Allee King Rosen & Fleming, Inc.
117 East 29th Street
New York, New York 10016-8022
(212) 696-0670
August 1995
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SOUTHOLD EKOSION IdANAGEHENT PLAN
August 1995
Prepared for: Town of Southold
Prepared by: Allee King Rosen & Fleming, Inc.
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SOuTHOLD EROSION MANAG~OU~T PLAN
TABLE OF CONT~qTS
ACKNO~2.EDGI~I~.NT S
~X~C~IvK S111414AR~
~APTER I. COASTAL PROCESS AND SHORELINE EVOI/]TION
A. COASTAL GEOMORPHOLOGY
COASTAL PROCESSES
Winds
Waves
Water Levels
Astronomical Tides
Storm Surges
Sea Level Rise
Currents
Sediment Characteristics and Supply
Storms
Human Activity and Land Use
Dredging
Hardened Structures
Soft Engineering Solutions
Land Use
Flood-Prone Areas
C. SUMMARY
~AI~ II.
A,
B. REACH 1:
C. REACH 2:
D. REACH 3:
E. REACH 4:
F. REACH 5:
G. REACH 6:
H. REACH 7:
I. REACH 8:
II~v~AITORY OF SOuTaOLD BY REACH
LONG ISLAND SOUND SIDE OF THE TOWN OF SOUTHOLD
TOWN LINE TO DUCK POND POINT
DUCK POND POINT TO HORTON POINT
HORTON POINT TO ROCKY POINT
ROCKY POINT TO ORIENT POINT
ORIENT POINT TO YOUNGS POINT (GREENPORT)
FANNING POINT TO FOUNDERS LANDING
FOUNDERS LANDING TO INDIAN NECK
INDIAN NECK TO DOWNS CREEK
J. REACH 9: DOWNS CREEK TO THE TOWN LINE
K. REACH 10: FISHERS ISLAND
Page
Number
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GIIAPT[.Jt III. COMMON M~NADI~IEN~ DNITS
A. INTRODUCTION
LONG ISLAND SOUND COAST
Jetty Areas
Areas of Low Bluffs and Dunes
Areas of High Bluffs
PECONIC BAY SIDE OF SOUTHOLD
Creek Mouths
Exposed Shores
Protected Shores
Flood Prone Areas
IV. PROPOSED E~OSION HANAO~NT POLICIES
A. PREAMBLE
POLICY STANDARDS
Policies Reflecting State Laws and for Setting
Priorities In Erosion Control Structures
Natural Protective Features
Policy to Protect Public and Public Trust Lands
Policy on Water-Dependent Uses
Policy on Expenditure of Public Funds for Erosion Control
Policy on Limiting Damage in the Coastal Area
C~A~r,.~ V. POST STOS.H RECOv~.~Y POLICIES
POST STORM RECOVERY
Introduction
Post Storm Recovery Goals by Common Management Unit
Long Island Sound Side
Jetty Areas
Low Bluffs and Dunes
Areas of High Bluffs
Peconic Bay Side
Emergency Permits
Cg&PT~VI. IH~T.~mTATION OPTIONS
IMPLEMENTATION OPTIONS
Studies
Capital Projects
Long-Term Coordination
LONG ISLAND SOUND EI~OSION HANAG~(NT POLICIES
III-1
III-1
III-1
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III-2
III-3
111-4
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~Ou'J.'aOLD EI~OSION ~.A..NAGE:M]~/~ I~I.A.N
T.T~T OF TABLES
I-1 Long Island Extreme Wind Velocity Records
I-2 Southold Area Fetch Distances
I-3 Southold Tidal Ranges
I-4 Historical Storms Affecting the New York Coast
I-5 Summary of the Volumes of the Sand Removed from
the Area West of Jetties of the Mattituck Inlet
I-6 Summary of Town of Southold Dredging Projects
~a~e l~mber
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1-14
1-16
1-17
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~hapter I
I-1
I-2
I-3
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I-7
~ROSION MAI~G~ pT~I~
LIST OF FIGURES
Typical Bluff-Backed Beach Profile
Typical Spit and Tombolo Formations
Storm-Induced Profile Erosion Schematic
Wave Height Estimates
Wave Period Estimates
High Tide Frequency -- New London, Connecticut
High Tide Frequency -- Willets Point, New York
Chapte~ II
II-1
II-2
II-3
I1-4
II-5
II-6
II-7
Southold Reaches
Geographic Names
Deduced Direction of Littoral Drift
Natural Shoreline Features
Environmental Sensitivity
Structural Shoreline Protection
Land Use
~hapter III
III-1 Common Management Units
Following
Page len~nber
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ACKNOWLEDGMENTS
This report is the synthesis of input and support from a large number of
people. Ruth Oliva, Town Deputy Supervisor, has spent long hours chairing
meetings with elected officials, agency personnel, and local citizens. Ruth
has been the main force behind producing this report and has been very support-
ive throughout the process. Town employees Valarie Scopaz, Town Planner, and
Jim McMahon, Community Development Director, have provided valuable resources
in developing the information base. They have collected information from nu-
merous sources, scouted out reports and other data~ and guided us on field
trips. Steve Ridler, Fred Anders, and John Novak of New York State Department
of State have provided technical guidance throughout our work and have provided
many insights on statewide policy concerns. We look forward to their review
and comments on this draft report.
A number of Southold residents have given of their time and shared their
knowledge with us. Many have submitted reports, photographs, and written re-
cords of their observations and comments on the effects of coastal processes in
Southold. Their help supplied the local knowledge that is vital to this type
of analysis. They include Donald Stanton, Reach 2; Whitney Booth, Reaches 2
and 3 (Horton Point); David S. Corwin, Reach 3; Louis Emmanuele, Reach 4;
William W. Wetmore, Jr., Reach 6 (Conkling Point); Judith Phiney, Reach 7 (Town
and Jockey Creeks); Ronnie Wacker, Reach 8 (Nassau Point); Joe MacKay, Reach 8;
Joe Gold, Reach 8; Harry P. Taylor, Reach 9 (Deep Hole and Downs Creeks); and
Norman Wamback, Rick Curcio, and Eugene Bozzo, Reach 9 (James Creek). We thank
each of them for their help, but reserve all errors and/or omissions in this
report to ourselves.
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EXECUTIVE S UHI~RY
CAUSES OF EROSION
The Long Island Sound Shoreline
The primary cause of erosion on Southold's Long Island Sound side is lit-
toral drift caused by wave action. When waves break on Southold's shore at an
angle, the water moves in the direction of the wave angle, taking sand with it
in a natural ongoing process called littoral drift. In Southold, the predomi-
nate direction of littoral drift is eastward, but major storms -- which can
generate waves higher than 6 feet -- often move the sand from east to west.
Generally, the cycle of beach building and erosion takes place over long
periods of low winds and waves action when the sand moves slowly west to east
and builds up a gently sloping beach. During the large winter storms, the sand
moves quickly from east to west and off-shore. These storms remove the sand
and leave behind a stone and cobble beach.
As long as the bluffs remain in a natural condition, the beaches heal
themselves over the summer and Southold's shoreline erodes slowly over time.
Points form around the areas with large rocks and cemented sands in the bluffs.
Areas with low bluffs and clayey soils become embayments. Although Southold's
Long Island Sound shoreline is eroding slowly, overall it is stable. However,
jetties to keep inlets open and groins and bulkheads to keep the bluffs from
eroding have, in places, taken the system out of equilibrium.
Because of the bluffs, coastal flooding is localized along this shoreline.
Very high tides rise to the toe of the bluff, but the houses are not flooded.
In certain low-lying areas, such as the east side of Mattituck Inlet, localized
flooding does occur.
The Peconic Bays Shoreline
The causes of erosion on Southold's Peconic Bays are more complex. Litto-
ral drift dominates in areas exposed to waves. Going from west to east, the
bays become smaller, and therefore the bay waves are smaller. The shoreline on
either side of James Creek is fully exposed to waves from Great Peconic Bay,
where the waves can reach a height of almost 5 feet. Robins Island affords
some protection to Cutchogue Harbor and the west side of Nassau Point, but the
east side of Nassau Point is exposed to Little Peconic and Hog Neck Bays.
Southold Bay and its waves are smaller. At the far east end of Southold, Hal-
lock Bay is almost totally enclosed. However, the Peconic shore, unlike the
Long Island Sound side, has no high bluffs. Therefore, when a storm causes
erosion, the shoreline quickly moves long distances landward. In addition,
flooding is common along the shore. To protect these low flat shores, over the
years property owners have built many groins to hold the beaches and bulkheads
to raise the ground level.
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CHAPTER I. COASTAL PROCESSES AND SHORELINE EVOLUTION
This chapter summarizes and is an introduction to coastal processes and
their interaction with Southold's shoreline. The intent of this chapter is to
present an overview of the coastal processes affecting Southold. Chapter II
contains the detailed, reach-by-reach description of Southold. As an introduc-
tion to the physical processes governing the evolution of the coastal environ-
ment and their complexity, the following is from the U.S, Army Corps of Engine-
ers' Shore Protection Manual (1984):
.... The beach and nearshore zone of a coast is the region
where the forces of the sea react against the land. The
physical system within this region is composed primarily of
the motion of the sea, which supplies energy to the system,
and the shore, which absorbs this energy. Because the
shoreline is the intersection of the air, land, and water,
the physical interactions which occur in this region are
unique, very complex, and difficult to fully understand.
As a consequence, a large part of the understanding of the
beach and nearshore physical system is simply descriptive
in nature.
A general discussion describing the physical coast with emphasis on the
Southold region is presented below. Included are the evolution of Long Island,
the forces that act on the shore, and its reaction to these forces. The chap-
ter is divided into three sections: 1) Coastal Geomorphology -- development of
Long Island and existing coastal landforms; 2) Coastal Processes -- forces
affecting shoreline change; and 3) Southold Coastal Conditions -- response to
normal and storm-induced conditions along the project shoreline (e.g., flooding
and beach and bluff erosion). A glossary of pertinent coastal engineering and
coastal geology-related terms is included for further reference. Primary ref-
erences used throughout this document include:
Governor's Coastal Erosion Task Force, Final Report, Volume II, Long-
Term Strategy (GTFII 1994);
o Shore Protection Manual, U.S. Army Corps of Engineers (USACE 1984);
North Shore of Long Island, Suffolk County, New York, Beach Erosion
Control and Interim Hurricane S~udy (Survey) (USACE 1969); and
Erosion of the North Shore of Long Island by Davies, Axelrod, and
O'Connor (Davies et al., 1973).
A. COASTAL GEOMORPHOLOGY
The marine coastline of the Town of Southold includes the shorelines along
the northern shore of Long Island from the western Town boundary (Mattituck
Hills) to Orient Point; the southern coastal areas fronting Gardiners Bay,
Orient Harbor, Shelter Island Sound, Hog Neck Bay, the Peconics (Little Peconic
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and Great Peconic Bays), and Flanders Bay: and Fishers Island in Block Island
Sound. Southold~s shorefront features include beaches, bluffs, dunes, wet-
lands, and barrier landforms. Topographic character and sediment composition
of the area determine the manner in which these landforms interact with the
marine environment, thus affecting coastal erosion and flooding. This section
summarizes the development of the Long Island coastal complex, including the
evolution of the shoreline and its landforms to the current configuration.
To fully understand the physical environment and its dynamic character,
its development must be examined historically. The following paragraphs, from
GTFII (1994), discuss the areats geologic history.
.... Glacial advance during the Pleistocene epoch generally
ended at the approximate centerline of what is now Long
Island (Fuller 1914). Seaward of the glaciers, extensive
outwash plains of sand and gravel were deposited on top of
pre-existing sediments and the gently seaward sloping At-
lantic Coastal Plain. Glacial termination along an east-
west front resulted in the present east-west orientation of
the south shore. Outwash glaciation resulted in sand depo-
sition on the adjacent continental shelf.
.... gently seaward sloping rocks of the Atlantic Coastal
Plain are buried beneath more recent semi-consolidated and
unconsolidated sediment. Pleistocene sediment deposited
over the last 2 million years was greatly modified during
the last glacial episode. Surficial sediment of Long Is-
land is composed of a variety of loosely consolidated gla-
cial material deposited primarily as moraine or outwash.
Further modification by rising seas over the past 15,000
years has resulted in the present geomorphic landforms.
About 20,000 years ago, the final period of glaciation, known as the Wis-
consian, glaciers stopped extending southward and started to retreat. This was
not a smooth, one-way process, but involved several advances and retreats.
Along Southold~s Long Island Sound shore, a ridge of glacial materials -- com-
prising clay, sand, cobbles, and boulders -- was deposited. This landform is
called a recessional moraine, and the Harbor Hill recessional moraine forms the
bluffs of the current shoreline. This recessional moraine contains highly
variable sediments that cause the changes in beach character along Southoldts
Long Island Sound shoreline.
Coastal areas are typically described both in profile and plan. A sche-
matic beach profile is depicted in Figure I-1 (refer to the glossary for defi-
nitions of specific terms). This profile is valid for almost all of the Long
Island Sound side of Southold. On the Peconic Bay side, it is valid without
the bluff for shoreline away from the creek mouths. Specific landforms common
along the Southold coastal region include beaches, dunes, bluffs, spits, tom-
bolos, inlets, and tidal and non-tidal wetlands. These landforms are defined
in the glossary included at the end of this report section, and are summarized
below.
Beaches. Along the seashore and acted on by waves, tides, and cur-
rents, the zone of unconsolidated material that extends landward from
the Iow water line to the place where there is a marked change in
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m, ,-- m ---- mm m m m m m m m m m m m .m m m
Coast Beach or shore Nnormhare ;off9 ~
'~ ~ (deflnnm nreu of nearmhore currents)
Backeharn _ r~emhorE~ _ Inshore or Ihorlfacl ~ _Offlhorl
~ - ~ (~xtendm through breaker zon~) ' ~
Bluff Surf Zone ~
Beach m~rp~ ~ I~ ~
Crest of berm /' -- ~~ {
Plunge point ~1
Bottom
Source: U.S. Army Corps of Engineers, Shore Protection Manual, 1984 '
Figure I- 1
Beach Profile and Definitions
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material or physiographic form, or to the line of permanent vegeta-
tion. Figure I-1 depicts the interaction of the sea with a typical
beach profile backed by bluffs. Beaches are found along the whole
length of Southoldts Long Island Sound shore.
Dunes. Ridges or mounds of loose, unconsolidated sand, that back the
beach, providing added protection against wave attack and flooding
during storm events. Dunes are found adjacent to Mattituck and Gold-
smith inlets and at Horton Lane Beach.
Bluffs. A high steep bank or cliff. Deposited during glacial move-
ment, these coastal landforms are highly susceptible to erosion and
collapse because of their steep seaward slope. Bluffs line much of
Southoldts Long Island Sound shore and the east side of Little Hog
Neck.
O
Spits. Formed when the dominant waves and currents carry sediment
into an elongated subaerial depositional feature, extending away from
a headland. Generally oriented parallel to the shoreline, with sedi-
ments transported along the trunk of the spit to its end in deeper
water, thus permitting the spit to grow longer. Spits grow in a
variety of shapes depending on local bathymetry, sediment supply,
tidal conditions, and wave climate. Spit growth often forms shore-
line features, such as cuspate bars and baymouth barriers. These are
commonly found on the Peconic Bay side of Southold. Typical examples
are the mouths of Town and Mill Creeks, as well as the elongation of
Nassau Point.
Inlets. A short narrow waterway connecting a bay, lagoon, or similar
body of water with a large parent body of water. Inlets are highly
dynamic with natural tendencies toward movement and closure, and
subsequent openings of more efficient inlets. They are often stabi-
lized for navigation requirements. The Peconic Bay shore of Southold
has many inlets, while only Mattituck and Goldsmith Inlets exist on
Southold's Long Island Sound shore.
Tidal and non-tidal wetlands. Tidal and non-tidal wetlands are low-
lying areas subject to frequent inundation by tidal flows or storm
tides, or merely having a relatively high water content. These areas
are established in locations with little wave energy, allowing vege-
tation to establish itself away from destructive wave energy. Along
Long Beach Bay, for instance, the protected shorelines have allowed
the establishment of extensive wetland areas.
Shorelines fronting Long Island Sound are characterized by nearly continu-
ous bluffs composed of loosely consolidated glacial outwash (primarily sand)
and moraine material, which is a mix of clay, silt, cobble, and boulder. The
glacials expanded from the north, carrying this mixture of sediments with it.
When the climate warmed, the advance of the glacier slowed, then stopped with
back-and-forth shudders. During this process, the morainal materials were de-
posited in a long ridge shape along the face of the glacier. As the glacier
retreated with the warming climate, sand was deposited in outwash plains. This
stopping and retreating formed what later became Southold~s bluffs, dunes, and
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beaches. Material eroded from the bluffs enter the littoral system, contribut-
ing to beaches of varying width, slope, and sediment character. Beaches front-
ing Southold consist of sediments ranging from sand to cobble, with widths
ranging from 25 to 100 feet. Portions of the coast are backed by dunes (e.g.,
east of Goldsmith's Inlet) and tidal wetlands, while some locations represent
low-lying coastal barriers (e.g., Truman Beach).
Shorelines fronting the Peconics are irregular and indented by numerous
inlets and bays. Coastal areas east of Shelter Island fronted by Gardiners Bay
are exposed to a moderate wave climate, while those west of Shelter Island and
along Long Beach Bay have minimal wave energy. The wave energy becomes greater
in Little Peconic Bay and greater still in Great Peconic. However, the fetches
(length of open water where wind waves can form) are longer in Gardiners Bay
than the Peconics. Beaches are generally narrow and sandy and predominate
along the eastern shoreline, with the exception of the wetland areas along Long
Beach Bay. Bluffs are relatively low and infrequent along the Peconics.
Shorelines backed by dunes are limited and specific to Orient Point State Park,
which is a spit formation. Tidal wetlands predominate along the western low-
energy shorelines, which are the result of the presence of Shelter Island.
Numerous barrier spits and shoals exist along the entire bayfront region.
B. COASTAL PROCESSES
Shoreline configuration is constantly changing as a result of varying hy-
drodynamic (water motion, water level, and other forces) and sediment process-
es. The evolution of a shoreline can be discussed both in the across-the-beach
profile and along the beach, which is often called longshore. This evolution
occurs during both normal low wave conditions and storms. During the storms,
the more spectacular changes occur, but the normal weather conditions act over
longer periods of time and are important in understanding beach evolution.
The movement of a beach in response to waves is referred to as littoral
transport, defined as the alongshore movement of sediments in the nearshore
zone by waves and currents. Transport direction is mostly determined by wave
steepness, sediment characteristics, and beach slope. Longshore transport of
sediments results from the initiation of sediment motion by incoming waves and
continued movement due to longshore currents. The magnitude and direction of
longshore transport is dictated by the angle of wave approach to the shoreline,
sediment characteristics and supply, and available wave energy. Direction and
magnitude of longshore sediment transport is highly variable from day to day.
Differences in longshore transport result in either accretion or erosion of the
shoreline, and are responsible for many of the current erosion hazards along
the project coast. Interruption of this longshore movement -- e.g. headlands,
inlets, and shore protection structures -- can result in significant impacts on
shoreline position. At Mattituck Inlet, for example, jetty construction and
channel dredging to reduce shoaling of the inlet channel resulted in erosion on
the east as the sediment supply was interrupted.
The across-the-beach profile (Figure I-l) continually adjusts to dissipate
the incoming wave energy. Beach response during normal conditions is subtle,
as wave energy is easily dissipated by the beach's natural protective features.
The beach will accrete sand from the littoral transport and become wider and
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6°¢$
,~i~e Crest
P o 'e - .or o o,,, aero. "'::':.':.~. ..~..~_
.... .-~:..::~
/~ ", :..':'..'~:.;:.;.: :i. : : i:.~:.;.::i.~.:: ~: : i.. : : ~:: !~.~.~; .:~.:.:~
.re,i[, 8 -~.i.o, attack et .... '<~_":'~
storm waves ~' "~"~ M L W
'Profile A
~...... ~,..~..:.~. ;.~-.---------------~
R eCc?sssti o n I.~. ACCR r..~~
'z."'~'~:'. ~l
· "'.'..?..~
/ '"~"2."2)[:;':.:::::'..'...:.::..;?...~.~.:.~''~ ~ ~
· ' ........... "'~'""' "~" M W
Profile D - After storm wave o ac~, "~.'...:~.L~
normal wave action ~ -"~'~'~;!'~
ACCRETION / -~'~
'Profile A "~
Source: U.S. Army Corps of Engineers, Shore Protection Manual, 1984
Figure I-2
Beach Response During a Storm
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higher. At the end of a summer, a beach will normally have stored a large
volume of sand. During storm conditions, however, the coast responds to in-
creased amounts of wave energy, often leading to the loss of significant quan-
tities of beach, dune, and/or bluff material. Figure I-2 illustrates a beach
response to wave attache during a storm. The foreshore is eroded and the back-
shore is often lost. During large storms, the dune system or bluffs are also
eroded. The beach slopes become flatter. Some of the eroded sand is deposited
in an offshore bar, and much can be lost offshore. These losses are sometimes
(but not always) temporary, except in the case of bluff erosion, which is a
permanent change to the coastal configuration.
~'inds
Winds over coastal regions result in coastal changes through three primary
mechanisms: 1) wind-generated waves, 2) wind-induced storm surges, and 3)
aeolian (wind-induced) sediment transport.
Generation of wind waves depends on the fetch (the distance over water
that the wind blows without interruption) and wind conditions (duration and
speed). During storm events when extreme wind speeds persist, water elevations
at coastal sites may increase as water piles up against the coastline. This
effect is a component of storm surge, which often causes flooding and extreme
wave attack damages. Aeolian sediment transport is a primary mechanism respon-
sible for either the growth or deflation of coastal dunes. Strong winds (gen-
erally exceeding 15 miles per hour) must be present to cause significant sedi-
ment movement by aeolian transport. Themagnitude of aeolian transport is
highly dependent on the presence of vegetation and/or moisture, both of which
reduce the movement of sediment. A wide beach is also necessary for dune for-
mation. Dunes are found in the vicinity of Mattituck and Goldsmith Inlets, but
the Town does not have the large dune systems that are found on Long Island's
Atlantic shore.
Wind data for long periods of record are available from observations at
the Brookhaven National Laboratory at Upton, the Suffolk County Department of
Public Works and Highways at Westhampton Beach, and the U.S. Weather Bureau at
La Guardia Airport for New York City. Short-term data are also available from
the U.S. Weather Bureau at Calverton Airport.
Average wind conditions for the northeast, southeast, northwest, and
southwest quadrants were estimated from the records at the four wind stations.
With minor exceptions for the station located at La Guardia, the wind direction
distribution for Long Island can be summarized as northeast, 20 percent; south-
east, 17 percent; northwest, 30 percent; and southwest, 33 percent. (Wind di-
rections refer to the direction from which the wind is blowing.) Winds from
the northern quadrant dominate during the winter, and winds from the southern
quadrant dominate during the summer. The wind velocity and storm duration
during the winter tend to be higher than during the summer. In the summer, the
percentage of calm conditions is over 10 percent, while calm conditions drop to
under 3 percent during the winter. These values summarize wind conditions in
the Long Island vicinity, but may not be directly applicable to Southold
because of their distance (La Guardia Airport) and different topographic set-
tings (Upton and Westhampton). Because wind data are not available for coastal
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areas along the north shore of Long Island, these data must be considered
representative.
In addition to long-term wind records, wind observations during storm
events are important for evaluating coastal changes. Data obtained during
storms were available for several locations, including Montauk Point, Block
Island, and La Guardia Airport. Table I-1 contains the pertinent maximum re-
corded wind velocities for some major storm events. The fastest mile and
5-minute average data are typically used to conduct wave estimates. The most
applicable information for Southold are records from nearby open-coast weather
stations. Block Island and Montauk Point data, therefore, are suggested for
use at Southold; La Guardia wind data are used to augment the records.
Table I-1
LONG ISLAND
~.x.r~g~.~D VELOCITY RECORDS
Velocity Type of
Location Date (mDh) Record
21 September 1938 82
21 September 1938 91
21 September 1938 96
Block Island
Block Island
Eastern End of Long Island
Block Island
Block Island
La Guardia Airport
Block Island
Block Island
Block Island
Block Island
Montauk Point
Montauk Point
Montauk Point
14 September 1944 88
14 September 1944 100+
25 November 1950 94
6-7 November 1953 95
6-7 November 1953 98
31 August 1954 105
31 August 1954 135
12 September 1960 105
12 September 1960 120
6-8 March 1962 68
5-minute average
Gust
US Weather Bureau
wind pattern
Fastest mile
Gust
Gust
Fastest mile
Gust
Fastest mile
Gust
5-minute average
Gust
Gust
Waves are created by wind blowing across the water with energy transferred
to the water surface. This energy transfer creates perturbations in the water
surface commonly referred to as wind waves (see Figure I-3 for a definition of
wave characteristics). The waves then travel across water until reaching land,
where they expend their remaining energy on the shore. Waves generated by
local winds blowing on shore typically reach the shore as steep (i.e., wave
length to wave height ratio is small) erosive waves called seas. Waves gener-
ated at great distances (hundreds to thousands of miles) prior to reaching the
shore will decay into long low waves referred to as swell.
The height, length, and period of wind waves at a coastal site are deter-
mined by the fetch, wind characteristics, decay distance, and water depth. In
general, increases in fetch, wind speed, and duration result in larger wind
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6*95
Direclion of Wave Travel
Region ------Trough L englh-----~ Level
Region d = Deplh
Ocean Bollom ~ / ~-
Source: U.S. Army Corps of Engineers, Shore Protection Manual, 1984
Figure 1-3
Wave Characteristics
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waves. Water depth, if shallow enough compared with the wave height and peri-
od, will affect wave characteristics, with wave breaking beginning when the
wave height is roughly 80 percent of the water depth. Waves generated by wind
are characterized by many combinations of height, period, and direction. This
combination of waves is referred to as the wave spectrum, which is often char-
acterized by representative wave parameters (wave height and period). Wave
conditions at any given location over a period of time can be described through
use of a wave spectrum, where characteristic wave conditions are referred to as
the wave climate.
Wave data for the north shore of Long Island have never been rigorously
collected. Waves that affect the shore are generated by local winds, as Long
Island and Block Island stop ocean swells from entering Long Island Sound
(Davies et al., 1973). Given the orientation of the Southold Long Island Sound
shoreline, winds from the northern quadrant and the west are primarily respon-
sible for wind waves along the coast. In the Peconics, the fetch is limited
compared with the Long Island Sound side, but waves large enough to cause ero-
sion can occur except within the creeks. Fishers Island is somewhat exposed to
ocean wave conditions from the southeast; however, waves traveling from the
ocean are affected by Montauk Point and Block Island. In general, the wave
climate at shorelines along Long Island Sound (Fishers Island) are moderate,
whereas shorelines along the Peconics and the majority of Gardiners Bay are
less energetic. USACE (1969) summarized fetch distances for the Long Island
Sound coast, that were augmented with approximations for the Peconics and Fish-
ers Island. Estimates for these locations are for the maximum single fetch
distance rather than the average distances used in wave calculations. The
fetch distance for Fishers Island corresponds to the breadth of Block Island
Sound, and excludes the narrow opening to the open ocean. These fetch dis-
tances are summarized in Table I-2. Wave heights and periods for shallow water
waves (waves interacting with local bathymetry) were hindcast using techniques
given in the Shore Pro~ection Manual (1984). Information used for these compu-
tations included water depths of 50 (no symbol) and 100 feet (with symbols),
fetch distances from 10 to 70 miles, and wind speeds from 10 to 120 mph. The
results are shown in Figures I-4 and I-5. While these results are not applica-
ble to any particular location along the project shoreline, they are represen-
tative of the relationships between various wave generation parameters.
~ater Levels
Elevation of the water surface can be considered as a long-term average
dependent on the volume of water contained in glacial form or as a short-term
change in water elevations as a result of astronomical tides, storm impacts,
and precipitation and ice melt (for rivers and small bays). The fluctuations
resulting from the combined effects of astronomical tides and storm surges, and
the effect of sea level rise on global ocean levels are of primary importance
for this report.
Astronomical Tides
Tides are created by the gravitational forces exerted by the moon and, to
a lesser extent, the sun. These forces of attraction -- coupled with the fact
that the sun, moon, and earth are always in motion relative to one another --
cause oceans to be set in motion. These tidal motions are very long period
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3S
3O
~5
15
I0
0
I0
20 30 40 50 60 70 80 90 100 110 120
WIND VELOCITY (mph)
-- 10 mdes
...... 70 redes
· 10 miles
-- · -- 40 redes
- - J-.70miles
Figure I-4
Estimated Wave Heights
-= m m m m m m ,m m m m m m mm m m m mm ,m
6*95
2
10
2O 3O
4O ~0 60 70 8O 00 100
WIND YFLOCITY (mph)
120
Figure I-5
Estimated Wave Period
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Location
Wildwood
Mattituck Inlet
Hashamomuck Beach
Orient Point
Fishers Island*
East Shelter Island
Little Peconic
Great Peconic
Table 1-2
SOu'£uOLD ARE~ FETCH DISTANCES
Fetch Distance (miles)
Northwest Northeast Southwest Southeast
27 30
50 20
49 14
17 11
45
6
10
2O
Fetch
(miles)
30
50
49
17
20
45
6
10
* To the Race that restricts short period wind waves but not swells
waves, and result in the periodic rise and fall of water levels along the
coast. The phasing of high and low tides is variable and important to the
level of wave attack along the shoreline. High tides in conjunction with
strong onshore winds, for example, cause increased shoreline erosion as large
waves break closer to shore in deeper water, thus exerting greater forces on
the shoreline.
Tides in Long Island Sound are semi-diurnal (occurring twice a day), and
the height increases from east to west due to the narrowing of the Sound, as
the area of the Sound lessens and the volume of water remains unchanged. Tidal
ranges for points within Southold are shown in Table I-3. Tides are given as
spring and mean tide for each location. The mean tide is the average tidal
range, and the spring tide is the tide that occurs at or near the time of the
new or full moon, which rises the highest and falls the lowest from mean sea
level.
Table
SOuTuOLD TIDAL HANCES
Tidal Range
(feetl
Location Mean SDrin=
Mattituck Inlet 5.0 5.8
Horton Point 4.0 4.6
Truman Beach 3.4 3.9
Orient Point 2.5 3.0
Southold 2.3 2.7
New Suffolk 2.6 3.1
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Storm Surges
Hurricanes and tropical storms are large wind fields, driven by central
low pressures and temperature gradients. These storms cause the water eleva-
tion at the shoreline to rise and flood the land. Several factors are in-
volved: wind stress, wave setup, barometric pressure reduction, and the Corio-
lis force. In response to the earth's rotation, the Coriolis force causes
water currents to deflect to the right in the northern hemisphere. These fac-
tors have caused increases in water elevations in excess of 13 feet above nor-
mal in Long Island Sound.
Wind stress and barometric tide are of primary importance to the magnitude
of storm surge. Height of the wind stress depends on wind speed and direction,
fetch, bathymetry, and nearshore slope. Basically, the wind drives the water
into the shore faster than it can return to open water. Either the water piles
up until the wind reduces in force, or the water reaches such height that grav-
ity forces it to return to open water. The barometric tide is the increase in
water surface elevation within the storm's low-pressure system. The higher
barometric pressure outside of the storm forces water in toward the lower baro-
metric pressure at the center of the storm. A Coriolis water level rise occurs
when the storm forces currents to flow along the shoreline. This component of
storm surge occurs in Long Island Sound, but is not particularly large. Howev-
er, it can also reduce the storm surge when the current direction causes the
Coriolis force to be directed toward Connecticut. The final component is the
wave set-up, which occurs in the surf zone when wave momentum transfers from
the waves to the water column. This component is important for large storm
waves where wave set-up may be as much as 20 percent of the breaking wave
height.
Factors that eventually determine the magnitude of the storm surge are the
stage of the astronomical tide (storm surge is superimposed on top of the tide
level), storm intensity, forward storm speed, and angle of storm track to the
shoreline. Shoreline configuration is also important in determining surge
elevations, much as shoreline configuration affects astronomical tides. This
effect is simply the funneling of water that occurs when there is a constric-
tion between two land masses. This occurs in Long Island Sound, causing water
levels in the western portion of the Sound to exceed those in the eastern sec-
tion. Increased fetch distances for wind setup also contribute to this effect.
Storm surge frequency relationships, available for many locations, are
either compiled and estimated from historical data or obtained through predic-'
tire techniques. These frequency relationships describe the annual probability
of occurrence for any particular water level event. The highest tidal height
ever observed was 13.3 feet above Mean Sea Level (MSL) at Willets Point during
the hurricane on September 21, 1938. At Port Jefferson Harbor during the hur-
ricane of August 31, 1954, a water surface elevation of 9.45 feet above MSL was
recorded. No extreme water level predictions have been prepared for the Town
of Southold, but extreme water level predictions for London, Connecticut are
considered to be representative for the Long Island Sound shore of Southold.
This is shown in Figure I-6. The highest predicted water level is 14 feet
above MSL, close to the physical maximum that can occur. The more commonly
used 100-year flood level is 10.7 feet above MSL. Although this is called the
100-year flood, it is a statistical measure, and that water level has never
been measured in Southold. Additionally, if it does occur, water could rise to
this level more than once in a given year. Having this storm surge once does
not mean that it will not occur for another 100 years.
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6,95
FREQUENCY IN YEARS
DESIGN HURRICANE TIDE EL, 14.0
/ 1938 ADJUSTED FROM A 229 YEAR PERIOD
/' 1. TO A 146 YEAR PERIOD
~ I [ 1954 ADJUSTED FROM A 225 YEAR PERIOD
~- ..... u , 1.TO A 146 YEAR PERIOD
HIGH SPRING TIDE
I I I
~ MEAN HiGH WATER 1
PERCENT CHANCE OF OCCURRENCE PER YEAR
Elevation Based on Recording Tide Gage Reading
or High Water Marks Referred to a 225 Year Period,
July 1938-December 1960, Inclusive
Elevation Based on High Water Marks Referred to a
146 Year Period, 1815-1960, Inclusive
Curve prepared by
New England Division, Corps of Engineers
Tewn ef gn.thold
Figure I-6
Extreme Water Level Predictions
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Sea Level Rise
Sea level rise can be separated imto two categories: 1) eustatic rise
(change in ocean elevation) and 2) relative rise (change in ocean level rela-
tive to adjacent land). Relative rise includes changes in both ocean and land
levels, thus including eustatic sea level changes. Causes of sea level rise
include changes in sea floor spreading, ocean and land area changes, tectonic
plate movement changes, thermal effects, ocean sedimentation, glacial charac-
teristics, hydro-isostasy, sediment isostasy and compaction/subsidence, ocean
surface topography and temperature/salinity effects, changes in the geoid,
geological faulting, and climatic effects (GTFII 1994).
Scientific evidence suggests that water levels during the peak of the ice
age were at least 450 feet lower than they are now, because of water contained
in glaciers. As the glaciers melted, sea levels rose about 0.3 inches per
year. Along the New York coastal region, the relative sea level rise over the
last 100 years (accounting for land rebound and sediment accumulation) is esti-
mated to have been from 0.04 to 0.14 inches per year. Historical sea level
rise rates are anticipated to continue, but there is much uncertainty about the
possibility of an increase. The effect of excess fossil fuel emissions, which
leads to global warming, would be to accelerate glacial melting. Past esti-
mates have been for sea level increases from 2 to 7 feet in the next century:
more recently, these estimates have been revised to less than 2 feet. Further
research is required to refine these estimates; thus, use of non-historical sea
level rise rates is highly subjective.
Despite the difficulties associated with predicting sea level rise, espe-
cially accelerated rates, it is an important factor in determining future ero-
sion patterns. As sea levels increase, low-lying areas become more subject to
flooding; magnitude of wave attack on previously protected shoreline locations
increases; and wetland areas could become inundated, exposing current inland
locations. These conditions are important in the Southold region for several
reasons. First, the bases of bluffs are particularly susceptible to sea level
increases, as current protective beaches would be rendered ineffective in pro-
tecting against wave attack. Once bluffs are exposed to more direct wave at-
tack, bluff recession would proceed at a relatively rapid rate. Therefore, the
rate of bluff erosion and shoreward migration along Southold's Long Island
Sound shore is likely to increase in the future. In addition, development in
low-lying areas along the Town shoreline, such as Fishermans Beach, would be
subject to increased flooding and landward movement or destruction of coastal
beach and dune systems. Finally, current protective measures -- e.g. bulk-
heads, revetments, and groins -- would be destroyed or at least rendered less
effective, and current Federal Emergency Management Agency Flood Insurance Rate
Map boundaries would be affected.
Nearshore currents play an important role in the evolution of coastal en-
vironments. Currents are driven by four mechanisms: 1) spatial differences in
water surface elevations, 2) wind, 3) angled wave approach to the shoreline,
and 4) river discharge. Significant currents can be generated by tides at
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inlets to bays or lagoons or at entrances to harbors. Currents at these con-
stricted entrances flow inland when the tide is rising (flood tide), and flow
outward as the tide falls (ebb tide). USACE (1969) reports that maximum cur-
rents along the north shore of Long Island typically range from 0.5 to 3.5
knots during floodtide and 0.6 to 4.3 knots on the ebbtide. Average currents
along Southold were reported as 1) Terry Point -- 2.7 knots (flood) and 3.2
knots (ebb); 2) Mulford Point -- 1.9 knots (flood) and 2.3 knots (ebb); and
3) Plum Gut -- 3.5 knots (flood) and 4.3 knots (ebb). High river discharges or
strong winds can alter these velocities, which can be seen in Long Island Sound
when strong winds from the west slow the ebb tide and allow the flood tide to
bring additional water and subsequent extreme water surface elevations into the
Sound.
Currents are created as wind blows over the water's surface, and stress on
the surface initiates movement in the direction of the wind. When the surface
current reaches a barrier, such as a coast, water piles up against the land.
This piling up of water, which is called wind setup and is a component of storm
surge, can create significant increases in water elevation when it occurs dur-
ing storms.
Another important mechanism in the nearshore region is the generation of
alongshore currents caused by waves approaching the shoreline at an angle.
This results in a gradient in nearshore surface elevations and induced cur-
rents, which tend to dominate during calm periods. Tidal current velocities
rapidly decrease as the shoreline is approached, and therefore, any littoral
movement is usually the result of wave action. This holds true for Long Island
Sound shorelines east of Port Jefferson, whereas the western areas are subject
to increased tidal ranges, which cause higher tidal current velocities.
Sediment ~haracteristics and Supply
Shoreline condition, in general, is affected by the amount of sediment
entering and leaving an area. Sediment supply is a major factor in determining
whether a coastal region is eroding, accreting, or stable. Along the Southold
coastal front, the primary sediment source is the glacial bluffs. Sediments on
most beaches range from fine sands to cobbles, with occasional large boulders.
Wave erosion of these bluffs -- along with the impacts of surface drainage,
rainfall, ground water seepage, and vegetative cover, and subsequent bluff
failure -- introduces large amounts of sediment to the littoral environment.
This material is then transported alongshore to other shoreline reaches at a
rate referred to as the longshore sediment transport.
The direction of longshore transport can often be deduced from the study
of existing landform. As sediment is transported in the nearshore and beach,
human structures can interrupt this flow. Sediment is deposited on the updrift
side, and the downdrift side suffers a loss of sediment. Sand can also be lost
offshore into deeper water because of these human structures. On the Long
Island Sound shore of Southold, the predominant direction of longshore trans-
port is toward the east. The jetties at Mattituck and Goldsmith Inlets inter-
rupt this flow, leading to accretion on the west side of the inlets and erosion
on the east side. Along the rest of the Long Island Sound shoreline, the head-
lands and points interrupt the flow during low wave periods, forming cells
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between the points. During storms, longshore transport occurs around the
points, primarily from west to east. This storm movement is thought to be the
dominant force in determining the direction of longshore transport on South-
old's Long Island Sound shoreline. On the Peconic Bay shoreline, the direction
of longshore transport varies greatly. The orientation of the shoreline dif-
fers by up to 180°. Therefore, one storm causes longshore transport in two or
more different directions on the Peconic Bay shore. Additionally, the many
inlets, with and without jetties, interrupt the longshore transport. The Pe-
conic Bay shore has many small cells for longshore transport, and cannot be
described in general as the Long Island Sound shore can.
The volume of sediment transported is an important parameter, and its
analysis requires a large amount of data. The problem needs to be studied in
all three dimensions to determine how many cubic yards of sediment are con-
tained in a foot of beach. Several seasons are needed over which to obtain
these data beach profiles. The profiles can be supplemented with aerial photo-
graphs to determine changes in form, but the photographs do not show elevation
changes. Without collecting and analyzing these data, only the most general
estimates of sediment volume and change in the longshore transport can be made.
Shoreline changes result from both day-to-day coastal processes and storm-
induced coastal processes. It is not certain which of these change mechanisms
is most important over the long term; however, it is clear that both play an
important role in coastal conditions. While shoreline changes under normal
conditions are nearly imperceptible, those that take place during a storm event
are often distinct.
As discussed earlier, storm winds typically generate high, steep waves in
conjunction with the storm surge. Increasing water levels expose higher por-
tions of the beach to wave attack, and allow large waves to pass over the near-
shore without breaking. At the point where the breaking occurs, which is often
close to shore, the remaining surf zone is insufficient to dissipate the in-
creased wave energy. This excess energy then causes erosion of the beach,
berm, dune, or bluff. The eroded material is carried offshore in large quanti-
ties and is deposited in a bar formation that grows to the point where the
large storm waves break farther offshore, spending their energy in the surf
zone. Ultimately, these storm-induced processes establish an offshore bar that
provides protection from storm wave energy.
Eroded beach material will often return to the beach berm during normal
conditions when waves assume an accretional character. This stage is referred
to as post-storm recovery. This recovery is fairly slow in Long Island Sound
because there are few long period swells to move sand from deeper water onto
the beach. Erosion of dunes is more severe, requiring re-establishment through
aeolian processes. Bluff erosion is most problematic because it is permanent
-- no post-storm recovery is possible. Although post-storm recovery does take
place, each storm removes some amount of beach material, decreasing its protec-
tive capabilities. Finally, storm waves and water levels can also damage coas-
tal structures and flood low-lying areas. Although damage resulting from these
mechanisms is more immediately evident and financially harmful, erosion of the
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coastal region is the avenue through which other storm-induced damages are
initiated.
Along the coastline of New York State, two types of storm events are of
significance: 1) tropical storms (originating in the tropics) typically affect
the New York area from July to October, and 2) extratropical storms (originat-
ing outside of the tropics), which are primarily less intense winter storms.
Hurricanes are the most powerful tropical storms to reach the New York
area, with wind speeds in excess of 74 mph. Historically, New York has been
hit by a number of hurricanes; 24 storms have been recorded in the New York
coastal region. Table I-4 lists several hurricanes. Because of the cold water
in the New York region, hurricanes move faster in the forward direction, which
increases the apparent wind speed. Many meteorologists also believe that it is
improbable that the New York area could be subject to a hurricane more powerful
than Class 4 (winds from 131 to 155 mph). Damage from this class of hurricane,
coupled with high forward speeds, would be tremendous. Alternatively, the high
forward speeds and relatively limited size of hurricanes reduce damages as a
smaller area is impacted and storm duration is limited. Furthermore, storm
damage magnitudes can be traced to the concurrence of high astronomical tides
and the storm surge, which act together to allow large waves to penetrate far-
ther inland, resulting in extreme erosion and flooding. The relatively short
duration of hurricanes often results in reduced damages, as water levels are
reduced by storm impact at a low tidal level. Recent hurricanes along the New
York coastal region have not resulted in significant erosion and flooding be-
cause maximum storm surges have coincided with low tide, as opposed to recent
extratropical storms that have occurred with high tides.
Extratropical storms originate outside of the tropics, usually in the mid-
to upper-latitudes during winter months. More commonly referred to as north-
easters, these storms are less intense than hurricanes but have localized winds
that often reach hurricane strength. Extratropical storms cover large areas
and are slow moving; typical storm durations last for a period of days. USACE
(1969) states that 65 moderate to severe northeasters have impacted the New
York coastal region over the 100-year period before 1965. More recently, a
series of severe northeasters has impacted the New York coastal region in Octo-
ber 1991, December 1992, March 1993, and December 1994. Table I-4 lists the
severe extratropical storms that have had significant impacts on the New York
coastlines.
Northeasters are similar to hurricanes in that damage to coastal areas oc-
curs from erosion and flooding stemming from high winds, large waves, and in-
creased water levels. Although wave heights and storm surges from extratropic-
al storms are less severe than from hurricanes, erosion and flooding can equal
or exceed hurricane-induced levels. Increased storm duration is the primary
factor that causes large coastal damages during northeasters. Because they
last days rather than hours, northeasters persist over numerous tidal cycles,
continually attacking coastal areas with several peak water elevations. In
addition, continued strong winds can trap much of the ebb tidal flow within
Long Island Sound, allowing flooding tides to augment existing high water and
cause extreme water elevations.
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Table I-4
HISTORICAL STORMS AFFKCTING T~l NE~ YOP~K COAST
Date
September 14, 1904
September 8, 1934
September 21, 1938
September 14, 1944
August 31, 1954
September 12, 1960
August 6, 1976
September 27, 1985
August 19, 1991
March 3, 1931
November 17, 1935
November 25, 1950
November 6~ 1953
March 6, 1962
February 6, 1978
March 28, 1984
October 30, 1991
December 11, 1992
Hurricane
Hurricane
Hurricane
Hurricane
Extratropical
Extratropical
Extratropical
Extratropical
Extratropical
Extratropical
Extratropical
Extratropical
Extratropical
Carol
Donna
Belle
Gloria
Bob
Damage from hurricanes and northeasters is highly dependent on storm in-
tensity and duration. However, the location of a storm relative to Long Is-
land's north shore is another major factor. Storm location is linked to storm
characteristics that determine where, relative to the storm movement, the most
severe conditions exist. Tropical cyclones are characterized as small fast-
moving storms consisting of a counter-clockwise spiral about the center (the
"eye") of the storm. This forward speed increases the apparent wind speed.
Winds to the right of the eye are most severe and are parallel to and rein-
forced by the forward storm speed. Therefore, since tropical storms travel in
a general northerly direction, south-facing coastlines are usually subject to
the greatest hurricane forces. North-facing coastlines, however, are somewhat
protected from the strongest storm impacts.
Similarly, extratropical storms are characterized by a counter-clockwise
spiral directed toward a central low pressure center. Wind direction and ve-
locity at a given coastal location depend on the relative location of the storm
track. The course of a northeaster to the east of the Sound is the most impor-
tant factor for the north shore of Long Island, where winds blow initially from
the northeast. Wind direction changes with storm movement to north-northwest
winds as the storm passes, and produces large wave heights and wind setup along
the north shore. Northeasters, with winds from the east occurring through
numerous tidal cycles, have historically had the greatest effect on the Long
Island Sound coastal region because of their long duration.
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Activity and Land Use
Dredming
Construction of shoreline structures and dredging operations are a major
factor affecting coastal erosion and flooding. Engineered structures -- e.g.
groins, jetties, bulkheads, breakwaters, and seawalls -- can halt, slow, or
exacerbate coastal erosion. Structures introduced to the coastal environment
to alleviate one problem often cause more severe problems, because the struc-
tures may have multiple influences on coastal processes. Other efforts, in-
cluding beach nourishment and dredged material placement, can be undertaken to
augment the coastal system by introducing additional littoral materials to the
coastal system without adversely affecting other locations. As beach erosion
and accretion, inlet opening and closing, bluff erosion, bay and wetland envi-
ronmental changes, and other changes to the coastal regime are natural and
ongoing processes, any alteration to the natural system will affect its dynamic
stability. To show the amount of effort and money expended to maintain an
engineered approach, Table I-5 presents the dredging that has been performed at
Mattituck Inlet. Human intervention in the coastal environment -- for the pre-
vention of flooding and erosion, reduction of inlet shoaling, or land develop-
ment -- is a short-term attempt to engineer a solution to a problematic coastal
condition. These interventions are often poorly engineered and fail to accom-
modate the dynamic nature of the coastal environment.
Construction of either hardened coastal structures (e.g. bulkheads,
groins, jetties, or seawalls) or soft methods (beach nourishment, vegetation,
or dune building) are attempts to stabilize beaches, bluffs, inlets, or barrier
landforms. Placement of hardened structures requires periodic maintenance and
mitigation, and often results in significant negative impacts. These can in-
clude downdrift erosion and loss of sediment offshore. Navigational needs also
lead to large disturbance of natural systems. Table I~6 lists the number of
projects and dredging volume performed out by the Town of Southold in Goldsmith
Inlet and on the Peconic Bay side.
Soft structures -- which are preferable and have less impact on the natu-
ral system -- may require frequent maintenance and could provide less protec-
tion against the problem in question. These soft solutions to erosion may not
be feasible for individuals, as large construction may be required for proper
performance. Although feasible and practical engineering of the coastal envi-
ronment is possible, construction must consider the range of impacts resulting
from such solutions. As discussed below, placement of dredged materials on
adjacent beaches is an important soft engineering approach in Southold.
Hardened Structures
Bulkheads, revetments, and seawalls are common along the coast of New
York, especially the northern shorelines of Long Island. The function of these
shore-parallel structures is to retard erosion of the upland while sacrificing
the beach and nearshore areas. The p,o_tent~ml ~ ~m~t{~rm im~act~ from thene
struct_qres_is apnmr~t my mmnv ]m~mn~. However, placement at sites with
a~equate~s~e(riment supplies can mitigate these impacts. The jetties at Matti-
tuck Inlet have caused erosion on the east side, which has lessened as sediment
has bypassed the inlet.
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S~ARy OF T~- VOLUMES OF THE SAND REMOVED
T~U~ Aero4 ~KST OF JETTIES OF THE NATTITUCK 1-NLKT:
1960-1975
Yards
Removed
1975 3,965
1974 364
1973 3,356
1972 9,502
1971 8,532
1970 7,208
1969 6,482
1968 15,914
1967 24,914
1966 25,808
1965 26,534
1964 20,032
1963 36,098
1962 14,734
1961 17,694
1960 23.214
TOTAL 244,351
Source: New York Sea Grant Service.
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Table I-6
SU~aKY OF TO~N OF SOu'l'UOLD DREDGING PROJECTS
Reach
1
Pro~ect Name
Mattituck Creekd
Cubic
Dates Yards
Dredged Dredged
1955 1,595,400
1
2
Long Creek 1967 13,000
(part of Matti-
tuck Creek)
Goldsmith Inletb 1977 4,000
1980 3,700
1982 6,000
1985 2,640
1987 4,800
Subtotal 16,340
North Sea 1992 12,~80
Gull Pond 1959 177~200
1960 28,500
1970 29,000
1979 23,300
1983 1,000
Subtotal 259,000
Sterling Basind 1959 163,900
1963 129,200
1976 12,000
1992 4,490
Subtotal 305,590
Mill Creek 1963 66,300
1968 2,700
1975 6,000
1979 4,000
1981 4,500
Subtotal 83,500
Town Creek/Harborc 1959 23,200
1959 93,400
1976 9,000
Subtotal
Jockey Creekc
Subtotal
Goose Creekb
Subtotal
125,600
1959 23,200
1959 93,400
1976 9,000
125,600
1959 46,700
1967 75,200
1968 11,100
1976 6,000
139,000
Method of Soil
Displacement
Upland site of Matti-
tuck Creek and Long
Creek
Beach nourishment
Beach nourishment be-
tween Gull Pond and
Sterling Basin
Formerly used wetlands
by cemetery, now use
back side of inlet for
beach nourishment
Upland on island to the
west
Beach nourishment to
the west
Beach nourishment to
the west
Formerly upland by Bay-
view Avenue, now beach
nourishment
Types of Hater
Dependent
Facilities
3 marinas and
park district
boat slips and
ramp
Matt-A-Mar
Marina is at
intersection
None
Town beach,
docking and
boat ramps
4 marinas and
a sailing club
3 marinas
Marina near
mouth of creek
and town ramp
on bay
Marina
Ramp
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Table I-6 (Continued)
SUMMARY OF T0~N OF SOuTuOL~ DP~DGINC PROJECTS
Reach
7
Project Name
Cedar Beach
Subtotal
7 Corey Creekb
Dates
Dredged
1979
1980
1981
1982
1983
1984
1985
1986
1987
1963-64
1967
1972
1981
1983
1984
1986
1987
Subtotal
7 Richmond Creek '
1959
1964
1967
1972
1983
1995
Subtotal
8 Broadwater Covea
1966
1976
1982
Subtotal
Cubic
Yards
Dredged
12,400
1,900
9,700
1,700
1,700
1,900
1,440
2,880
1,920
35,540
345,600
23,900
7,600
10,200
800
3,500
18,600
5,040
315,240
123,000
82,800
25,100
5,500
15,300
20.000
271,700
434,400
11,000
10,200
455,600
Method of Soil
Displacement
Types of Water
Dependent
Facilities
Beach nourishment to
the west
Marine Tech-
nology Dept.
of Suffolk
County Commu-
nity College
Formerly upland and now Ramp
beach nourishment
Beach nourishment on
beth sides of inlet
None
Upland disposal adja-
cent to creek
Formerly upland on 2
sites, now beach nour-
ishment to the west of
inlet
Marina
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Table I-6 (Continued)
SUHNA~Y OF TO~IN OF SOUTHOLD DREDGING PROJECTS
Reach Proiect Name
8 Little Creekb
8 Mud Creeka
Subtotal
Subtotal
8 East Creeka
Cubic
Dates Yards
DredKed DredKed
1967 51,000
1968 3,700
1975 5,000
1976 40,000
1978 4,000
1979 5,000
1980 2,400
1981 2,400
1981 5,500
1982 7,000
1983 2,400
1983 2,300
1984 2,400
1984 6,000
1985 3,120
1986 5,760
1987 8,400
1991 4,000
1992 4,740
1993 5,000
170,120
1966 434,400
1976 11~000
1982 10,200
1987 6~600
1992 2.910
465,110
1966 434,400
1976 11,000
1982 10~200
Subtotal
8 Wickham Creek
Subtotal
8 Schoolhouse Creek
455,600
1966 48,300
1972 10,000
1979 3,600
1981 1,700
1982 2,200
1983 1,900
1984 1,400
1985 1,440
1986 2,640
1987 2,640
1992 1,500
77,320
1976 12,000
Method of Soil
Displacement
Beach nourishment on
both sides of inlet
~es of Water
Dependent
Facilities
Ramp/Moorings
Formerly upland on 2
sites, no beach nour-
ishment to the west of
inlet
None
Formerly upland on 2
sites, now beach nour-
ishment to the west of
inlet
None
Beach nourishment to
the west
Marina
Beach nourishment
Marina
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Table I-6 (Continued)
SU~WARY OF TO~N OF SOuT~OLD DREDGING PROJECTS
Pro~ect Name
New Suffolk
Reach
8
Subtotal
West Creekb
Subtotal
Halls Creekc
Subtotal
Deep Hole Creek
Subtotal
9 James Creek
Subtotal
Dates
DredKed
1977
1979
1980
1981
1982
1983
1984
1985
1986
1987
1993
1966
1976
1982
1979
1980
1964-65
1972
1975
1976
1980
1980
1982
1983
1987
1991
1993
1964-65
1979
1980
1983
1985
1986
Cubic
Yards
DredKed
4,000
1,500
1,000
2,000
3,300
1,000
1,800
2,500
1,250
1,500
2,000
21,850
92,500
9,000
2,800
101,800
17,400
4,200
21,600
243,500
21,100
4,000
14,000
5,000
10,000
8,800
6,300
7,680
4,600
10.600
33S,580
272,500
3,000
6,700
9,400
5,250
1,570
298,420
Method of Soil
Displacement
Types of ~ater
Dependent
Facilities
Beach nourishment on Boat ramp
town beach to the south
Beach nourishment on
both sides of inlet
Ramp
Beach nourishment to None
the east
Beach ~ourishment on None
both sides of inlet
Formerly upland to the
east, now beach nour-
ishment on both sides
of inlet
2 marinas
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Table I-6 (Continued)
SU~WA~Y OF TO~N O~ SOuTuOLD DREDCINC PROJECTS
Cubic
Dates Yards Hethod of Soil
Reach Project Name Dredged Dredged Displacement
9 Brushs Creek 1966 86,400 Beach nourishment on Marina
1975 7,500 both sides of inlet
1979 5,000
1980 1,900
1981 5,800
1983 1,500
1984 4,800
1985 6,750
1986 3,000
1991 3,000
1992 1.530
Subtotal 127,180
10 West Harbor 1971 43,100 Dumped at sea
(Fishers Island,
channel connect-
ing to federal
project)
-- Wunneweta Lagoon 1991 2,700
1993 1,000
46,800
Subtotal
Types of ~ater
Dependent
Facilities
TOTAL 5,875,470
Hotes:
Broadwater Cove, Mud Creek, and East Creek were dredged as one project in 1966,
1976, and 1982.
The Suffolk County Department of Health Services has determined that dredging
Goldsmith Inlet was necessary in 1985 to protect the public health.
Jockey Creek and Town Creek/Harbor were dredged as one project in 1959 and 1976.
Mattituck Creek and Sterling Basin are federally authorized projects.
Analysis of Dredging and Spoil Disposal Activity Conducted by Suffolk
County, County of Suffolk, New York, Historical Perspective and a Look
to the Future, Suffolk County Planning Department, October 1985; Annual
Environmental Report, Office of the Suffolk County Executive, 1987,
1988, 1992, 1993, 1994,
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To illustrate possible negative impacts, a structure placed at a location
that experiences chronic long-term erosion is analyzed here. The structure
essentially removes the upland sediments from the coastal regime, thereby pin-
ning the shoreline to a given location. Under natural conditions, the upland
would provide the sediment necessary to maintain a protective beach, but would
result in permanent loss of the upland. The structure pins the shoreline posi-
tion but does not alleviate the erosional condition. Nature often finds an
alternative sediment source, which results in accelerated erosion of the beach
directly in front of and adjacent to the structure. Following or prior to the
loss of protective beach, beach nourishment is necessary as a mitigation ef-
fort. Should the situation not be mitigated, the beach might totally disap-
pear, resulting in direct wave attacks on the structure. This condition often
leads to structural failure and severe erosion of the upland that can even
exceed that which would have occurred had no protective measures been
constructed.
Breakwaters are hard structures that are offshore and parallel to the
shoreline and that act to reduce the wave energy behind the breakwater before
it reaches the coast. By reducing the wave energy, breakwaters allow littoral
materials to deposit, which leads to the formation of a protective beach. Ac-
cumulation of beach material behind the breakwater reduces the littoral mate-
rial available for other shoreline reaches unless beach nourishment or other
mitigation measures are undertaken. The very large rocks that can be found on
Southold's beaches or just offshore serve as breakwaters on a very small scale.
Accretion occurs just behind them.
Shore-connected and perpendicular structures, called groins, are used
along many shorelines. These structures intercept littoral material, which
results in the accumulation of a beach updrift of the groin. Downdrift of the
groin, however, the littoral material is reduced, which often leads to erosion.
As with other coastal structures, beach nourishment can mitigate this impact.
One mitigation method is a series of groins, with beach nourishment filling in
the groin compartments. Since the groin compartments are at capacity, long-
shore sediments can bypass to downdrift beaches, thus minimizing negative im-
pacts on the littoral supply. However, the groins must not be constructed in
such a way that the sand is transported offshore and lost from the littoral
system. This distance offshore is related to the width of the surf zone under
normal conditions, which -- in an area like both sides of Southold -- can
strictly limit the allowable groin length. The groins on the Peconic Bay shore
of Southold provide illustrations of every type of groin field imaginable.
Stone, concrete, steel, and wood have all been used as construction materials.
The length, height, and spacing of the groins have varied from very short, low,
and closely spaced, to a single high groin sticking out into the middle of the
bay. These groin fields are described in the next chapter, where their effec-
tiveness is [partially] assessed. However, each set of groins would have to be
individually studied to accurately estimate their usefulness and their effect
on neighbors.
Jetties are another shore-perpendicular structure used to stabilize inlet
positions and reduce channel shoaling. Littoral material is intercepted by
jetties in a manner similar to groins. However, the negative effects of jet-
ties on the downdrift shorelines relative to natural inlets and frequent chan-
nel dredging are of greater magnitude. Jetty-stabilized inlets intercept a
great deal of sand, and a series of jetties increases this effect, decreasing
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the volume of sand traveling in the downdrift direction. Inlet stabilization
also appears to deposit larger volumes of sediments in ebb and flood tidal
shoals compared with natural inlets. In natural inlets, sand is distributed
along the ocean and bay shorelines as the inlet migrates alongshore, which
reduces the volume of material trapped by the inlet. Natural inlets allow more
material to bypass to downdrift sections; therefore, whether jetties are pres-
ent or maintenance dredging alone is used, inlet maintenance leads to downdrift
sand deficits. Many jetties have been built at the mouths of the inlets on the
Peconic Bay shore. These jetties are described in the next chapter, where some
assessment of their effectiveness is given. However, each inlet needs to be
individually studied to accurately estimate its effects.
Soft Engineering Solutions
Soft structures are often preferable to hardened structures, and represent
an attempt to work with the natural system by augmenting its natural defenses.
Soft engineering solutions include beach nourishment (placement of beach sedi-
ments to create a larger protective beach and dune system), beach shaping, sand
fencing (to help the dune-building process), and vegetation (to stabilize ex-
isting dunes or trap additional wind-blown sand). Beach nourishment is accom-
plished by delivering sand to the beach or dune from either an offshore or up-
land site. This is a temporary solution to erosion and flooding problems,
since the placed material is sacrificial and only offsets existing erosion
problems. Although this method requires frequent maintenance, it has few
detrimental environmental consequences. Large-scale beach nourishment is often
augmented with coastal structures, when there is severe long-term erosion
(greater than 3 feet per year, typically). Beach nourishment is usually less
expensive than hardened structures; however, should insufficient material
sources be unavailable or projects be undertaken by local interests, costs may
increase. Beach nourishment is an effective mitigation technique, whether or
not combined with coastal structures or inlet dredging and stabilization. At
inlets, bypassing of materials from either updrift beaches or channel dredging
operations to downdrift beaches is an effective and feasible solution to reduc-
ing downdrift erosion. Beach nourishment -- sometimes combined with breakwa-
ters, bulkheads, or groins -- may also lessen the impacts of these structures
by introducing additional material to the littoral system.
Beach scraping augments dune profiles and beach berm widths to provide
additional recreational beaches and protection against flooding. The technique
consists of removing sand from the nearshore and scraping it up on either the
berm or dune. It has been questioned whether beach scraping is an effective
means of preventing erosion. Although increasing the volume of the dune pro-
file is a practical way to create additional flood protection, the steepening
of the beach face may actually increase erosion and loss of beach material dur-
ing storms. Beach scraping has also been described as an effective tool for
dune building that, when properly conducted, leads to no significant negative
impacts. However, it introduces no additional beach material to the system,
and its effectiveness in providing protection in eroding areas is therefore
limited.
Sand fencing and establishment of vegetation are other techniques used to
provide additional flood protection by increasing dune volumes. These attempts
at dune restoration use wind-driven sediment transport to capture necessary
sediments. This approach seems to have been successful at New Suffolk. Since
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this is an environmentally sound and low-cost effort, many communities under-
take dune restoration projects. Increased dune volume protects upland areas
from flooding during storm events and reduces beach erosion by acting as reser-
voirs of additional beach material. Because of frequent erosion of the dune
during storm events, the success of dune building projects depends on continued
effort and vigilance.
Land Use
Human activity brings additional forces into the coastal area that often
cause erosion. At its simplest, dunes that store sand are stabilized by shal-
low-rooted vegetation. People walking across the dunes break the root systems,
weakening the plants and leading to their destruction. Without the vegetation,
the dune is easily eroded and the sand is lost to the beach system. A public
beach draws a large number of people who require parking and amenities, such as
changing rooms and food supply. These requirements mandate that the shoreline
must be managed and not allowed to vary greatly in its width or position. This
management can range from restricting times of year when the beach is open to
constructing large-scale, hard structures, including groins and breakwaters.
Beach nourishment using sand from other areas is an intermediate approach that
is often used.
Unless large buffer distance is available, residential use creates the
same situation. If the shoreline erodes, improvements on a lot, such as hous-
es, become endangered. Some type of shoreline stabilization is demanded to
protect homes. Because home owners usually have limited financial resources,
stabilization projects taken on by individuals tend to be small. Public use
includes roadways, which have public investment and are needed for public safe-
ty and emergency services. Therefore, large, heavy structures are built to
protect the road. These often disrupt the beach system and lead to further
erosion which leads to further construction. Commercial activities, such as
motels and restaurants, make similar demands and their approach tends to be an
intermediate one, between private residential uses and public facilities.
Boating, with its need for vertical bulkheads and deep water next to the
shore, also affects erosion. In Southold, the marinas' private moorings are in
inlets where erosion is not a major concern. However, inlets naturally shoal,
close, and change position, none of which are acceptable to boaters and marina
owners. Boating leads to the demand for dredging, which has been discussed
above.
Flood-Prone Areas
The danger from large storms is not limited to erosion from wave action;
flooding from elevated water levels damages properties, some far inland. As
discussed earlier, the maximum water level expected in the Long Island Sound
shore of Southold is about 14 feet above MSL, and the 100-year flood level is
about 10.7 feet. These levels are lower on the Peconic Bay side. Because of
the bluffs, most of the inhabited areas of the Long Island Sound shore are
above these elevations. The four exceptions are the mouth of Mattituck Inlet,
Goldsmith Inlet to Kenneys Road Beach, Hashamomuck Beach, and Truman Beach. On
the Peconic Bay side, much of the shoreline and inlets is subject to flooding.
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There are fewer areas above flood elevations than areas that are subject to
flooding. With the exception of Little Hog Neck, almost all of the shoreline
is just about or slightly more than 10 feet above MSL. While most houses do
not flood regularly, such areas as Fishermans Beach and Marratooka Point flood
several times a year.
C. SUMMAKY
This report describes the evolution of existing coastal landforms and the
specific processes that govern the continuous landform changes. Where explana-
tions were necessary, the processes were presented in cause-and-effect rela-
tionships -- e.g. the relationship between wind and waves and erosion of
beaches. The section provides a concise frame of beach and water interactions
and the physical problems that apply to Southold, as well as the reasons for
problem areas. In sum~mary, the primary concerns within the Southold area in-
clude long-term and storm-induced beach/dune and bluff erosion, and the flood-
ing and erosion of low-lying areas associated with storm events.
Beaches are composed of loosely compacted sediments, usually sand or
gravel. The beach profile shape depends on the incident wave energy and sedi-
ment size. Beaches are dynamic; most change annually due to varying wave cli-
mates. During the summer months, relatively long-period waves of low height
persist, causing the subaerial (above-water) beach to be at its maximum width.
As winter approaches, waves become steeper and tend to move material to an
offshore bar that reduces wave energy on the beach face. This offshore move-
ment reduces the subaerial beach width, yet represents an equilibrium with the
winter storm climate. The cycle is repetitive, as summer approaches with the
onshore movement of beach material from the offshore bar. A noteworthy feature
of this cycle is the change in beach composition from season to season as the
finer beach material is more readily transported, which causes a sandy summer-
time beach to be primarily cobble during winter months.
During storm events, this cycle is amplified as larger waves erode the
beach face and carry more sediment to an offshore bar. With the attendant in-
creased water levels, waves attack and erode dunes and bluffs, and deposit
material offshore. The growing bar in turn reduces the magnitude of wave at-
tack on the beach face, dunes, and bluffs, thus providing a natural defense
system. After the storm, the normal wave climate moves material onshore to the
beach and re-establishes the normal seasonal profile. Problems occur when
eroded bluff and dune materials are not returned to their pre-storm locations,
but only reach elevations of maximum wave uprush on the subaerial beach. Dur-
ing severe storms, beach material is moved beyond the point of sediment motion
under normal conditions, which effectively removes the material from the near-
shore coastal environment. Dune and bluff erosion occur through these proc-
esses, requiring human intervention to mitigate the losses.
Glacial bluffs are a prominent feature along the Long Island Sound shore-
line; understanding the processes that cause bluff recession is critical.
These bluffs, which can approach 100 feet, are composed of unconsolidated sand.
Roughly 75 percent of these bluffs are vegetated (stable), while the remainder
are uncovered and actively eroding (Tanski, 1980). Some bluff areas are esti-
mated to erode at rates as high as 6 feet per year. Erosional sections are
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mostly storm related and are caused by undercutting of the bluff by waves or
tidal currents. Groundwater seepage, overland runoff, vegetation density, and
bluff geometry and composition are other factors that affect bluff erosion.
Once bluff erosion is initiated, the bluff steepens beyond a stable value,
which is subsequently followed by slope failure and marked recession. Although
bluff erosion is complex and difficult to predict, it is easily monitored and
readily stabilized through engineered means. These stabilization efforts, how-
ever, often fail to recognize the importance of maintaining the bluffs as a
component in the littoral environment. In addition, they are expensive to
construct and maintain.
Bluff erosion is particularly noteworthy along the Southold shorelines,
where a high percentage of the total coast is fronted by glacial bluffs. Ero-
sion processes are different from beach and dune erosion because bluffs serve
as the major reservoir of sediment along the shoreline. As beaches are inun-
dated and move landward, bluff material is introduced to the littoral environ-
ment. This material is then transported alongshore or offshore, resulting in
further erosion of the bluff. The continuous process is a natural equilibrium
in which the bluff sacrifices a volume of material to the beach to prevent
further bluff erosion. Unfortunately, bluff erosion (unlike dunes) is perma-
nent, which leads to efforts to stabilize bluff faces against further erosion.
The flooding of low-lying areas that results from overtopping of beaches,
dunes, and coastal structures occurs along the Peconic Bay shoreline. Flooding
alone causes a significant amount of damage to coastal communities, but also
results in the loss of beach material as flood waters carry large volumes of
sediments to backshore areas. This problem is particularly severe on barrier
beaches and islands, and represents the natural tendency for these systems to
move onshore.
The continued alongshore movement of sand that is dependent on wave direc-
tion and height is superimposed on cross-shore movement of sand on the beach.
Gradients in this alongshore movement erode or accrete beaches. Long-term
erosion up to 2 feet per year and annual accretion rates of nearly 2 feet have
been estimated along the Long Island Sound shoreline in Southold (Davies et
al., 1973). In general, the shoreline is erosive with sparse accretional
shoreline sections. Significant problems occur when littoral material is in-
tercepted by coastal structures or inlets -- e.§., at Goldsmith's and Mattituck
Inlets. At Mattituck Inlet, for example, annual updrift shoreline changes
reflect roughly 3 feet per year of accretion, and downdrift erosion rates ex-
ceed 1 foot per year. Downdrift erosion is a particular problem of stabilized
inlets and groins and results in steep narrow beaches that are unable to pro-
vide necessary storm protection.
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CHAPTER II. INVENTORY OF SOUTHOLD BY REACH
This chapter provides a reach-by-reach description of the coastal process-
es and landforms. This inventory is general in nature and is intended to give
some insight to the conditions. Each reach needs a detailed study to provide
specific recommendations for a parcel or groups of data in an area.
The inventory is summarized in seven sketches that provide an overview of
existing conditions in Southold. Figure II-1 shows the reaches and major
shoreline configurations. Geographic names in the narrative are presented in
Figure II-2. Figures II-3 through II-5 indicate major natural considerations,
including deduced littoral drift, natural features, and environmental sensitiv-
ity. Results of human activities are featured in Figures II-6 and II-7.
A. LONG ISLAND SOUND SIDE OF THE TOI~ OF SOUTHOLD
This side of the Town of Southold is exposed to the waves of Long Island
Sound from 9 to more than 20 miles fetch, generating waves from up to 6 to more
than 9 feet in 75 mile-per-hour, hurricane-force winds. Wind-generated waves
are the primary cause of coastal erosion; certain individual areas are greatly
affected by their orientation toward the waves. During the 1990's, points fac-
ingrth~m~have been heavily eroded by four major storms: Hurricane Bob,
the~a~i-i-6~een storm, and the storms of December 12, 1993, and December 24,
1994. Shorelines with a more northerly exposure have not been as affected in
the 1990's. Bluff composition and height are also very important factors in
calculating erosion levels. The silty-clayey sediments in Pettys Bight have
been heavily eroded while the rocky points, such as Horton Point, have resisted
erosion forces more successfully. H~ffs, such as those east of Nattituck
Inlet, have supplied ]mrna vnl ..... of smmd to thm ~hmre]ine. Low bluffs or
dunces do not provide the necessary volume of sand; and the do~es
B. REACH 1: TOWN LINE TO DUCK POND POINT
The coastal erosion processes in Reach 1 are dominated by the jetties at
Mattituck Inlet, which block the normal littoral drift. Because of this block-
age, the shoreline has changed over a period of time. The predominate drift
direction is from wm~t to east, but waves from large storms often come from the
northeast and move~the sand from the east toward the west. Reach 1 east of
Mattituck Inlet appears to have stabilized due to the jetties. The area next
to the west jetty has filled with sand, which is migrating around the end of
the jetty into the channel. The shoreline from the town line to the west jetty
is smooth.
The east side of Mattituc~Inlet does not appear to have stab,~lized. Just
east of th~e--i'n£%t"i the beach ~s eroding and the l~w dunes nave not been able to
supply sufficient sand to replenish the volume blocked by the jetties. The
bluff, which rises to between 80 to 100 feet at Oregon Hills, has been attacked
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6,95
LONG ISLAND SOUND
ORIENT
~'] HARBOR
PLUM
ISLAND
ISLAND
[] Reach Number
LITTLE
HO~ NECK
NOYACK
SPRINGS
0 2 MILES
SCALE
Figure I1-1
Southold Reaches
7.95
PLUM
ISLAND
SPRINGS
NORTH SEA
0 2 MILES
[] Reach Number
Figure 11-2
Geographic Names
m mm m m .m mm m mm m m m m m m m mm mm m
7'95
ISLAND
PLUM
ISLAND
MAi iiiUCK
ROBINS
ISLAND
GREAT
PECONIC
BAY
// NOYACK
/
/
SPRINGS
0 2 MILES
SCALE
[] Reach Number
--" Deduced direction Figure 11-3
Deduced Direction of Littoral Drift
7*95
[] Reach Number
~!;~:ii~:iii::i'i;~;: Inlets
............. High bluffs
...................... Low bluffs
~.~. Flood prone
0 2 MILES
SCALE
Figure 11-4
Natural Shoreline Features
m m m m m m m m m mm m m m m m m mmm m m
8,95
SPRINGS
· NOR111 SEA
0 2 MILES
SCALE
[] Reach Number Marsh
~.~ Bird Nesting Figure 11-5
Environmental Sensitivity
7'95
HOG NEC~
MATTITUCK
.R-ANDER$
BAY
[] Reach Number
Town of Snu~h;ld
PECONIC
BAY
NEW SUFFOLK
PECONIC
BAY
/
/
/
/
/
/
· NORTH SEA
Heavily structural
Medium structural
Light or non-structural
NOYACK
SPRINGS
0 2 MILES
SCALE
Figure 11-6
Structural Shoreline Protection
7e95
ISLAND
PECONIC
BAY
[] Reach Number ......... Public usos
~" Sma//lots m Commercial uses
LONG IS~ND SOUND
ORIENT
PLUM
ISLAND
~E
PECONIC ~
u,~ BAY
ROIMN$ ~/ NOYACKe
~,.,l~sL~D /
/
/
/
/
· NORTH SEA
ISLAND
0 2 MILES
SCALE
Figure 11-7
Land Use
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at the toe and has slumped in a number of locations. These slumps have been
supplying sand along this reach. Because of erosion, the foundations of a
hotel constructed on the beach at the end of Duck Pond Road have been under-
mined.
C. PEACH 2: DUCK POND POINT TO HOKTON POINT
The bluff is 40 to 60 feet high east of Duck Pond Point for about 7,500
feet. About 2,000 feet of various bulkheads have been built along the stretch.
The bluff then drops to about 20 to 40 feet high, and ends at Goldsmith Inlet.
Jetties were built at Goldsmith Inlet in the 1960's as part of a New York State
plan for a marina in the park, but the marina was never built and the inlet is
not navigable. It would probably close except that the Town dredges it yearly
for the sand. The shoreline west of the jetties has come back into equilibrium
with the coastal dynamics. The shoreline to the east, however, does not re-
ceive sufficient sand and is eroding, despite the construction of several
groins and bulkheads. The problem is most severe at the easterr~ost beaches,
where oversized groins disrupt the littoral drift and may cause the sand to be
lost offshore. The low dunes do not store sufficient sand to compensate for
the erosion. The easternmost stretch has not experienced much erosion; accord-
ing to long-time residents, it has actually accreted sand. Horton Point pro-
trudes far enough into Long Island Sound to provide protection from most
storms. The angle of Horton Point makes the waves diffract around it, weaken-
ing their energy before they break on the shoreline.
D. REACH 3: HORTON POINT TO ROCRY POINT
The conditions along Reach 3 are variable. While portions of the shore-
line are stable, others remain unstable, causing damage to several houses. At
Horton Point, the bluff is high, and the shoreline has smoothed out over the
past 60 years. Although some erosion has occurred, there has been no property
damage. After about 4,500 feet, there are protective shoreline structures even
though the high bluff continues for about another 3,000 feet. Various types of
structure and building materials have been used in this 3,000-foot length of
shoreline west of Town Beach, but they have either been ineffectual or in-
creased erosion. The Town Beach has been eroding; to the east, the shoreline
has experienced severe erosion. The December 1994 storm led to the condemna-
tion of two houses, and County Road 48 is threatened in several areas. About
7,000 feet east of Town Beach, the bluffs reemerge and the shoreline is gener-
ally stable through Inlet Point. Because Inlet Pond sits between the bluffs
and Long Island Sound, exceptionally high tides can result in water overwashing
the beach at Inlet Point. From Horton Point to Inlet Point, the predominate
drift direction is from west to east. The bluffs are very steep from Inlet
Point to Rocky Point, and the beaches are generally stable and very rocky.
E. REACH 4: ROCKY POINT TO OKIENT POINT
The first 4,000 feet of Reach 4 extends almost due east-west and has a
steep bluff. This very rocky area has been fairly stable. The bluffs then
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give way to a smooth embayment that includes Truman Beach; East Marion Orient
Park -- an area that has eroded over the years -- is to the east. From Terry
Point to Mulford Point, the shoreline is rocky and backed by a steep bluff. The
area from Mulford Point to Orient Point, known as Pettys Bight, has recently
experienced severe erosion. Although no erosion problems were reported for 30
to 40 years, the five major storms in the 1990's have caused large-scale ero-
sion. The area around Orient Point also narrowed during these storms.
F. REACH 5: ORIENT POINT TO YOUNGS POINT (GREENPORT)
Like all of the Bay side shoreline, Reach 5 has a wide range of erosion
potential and causes. Orient Point is fully open to Gardiners Bay and experi-
ences waves similar to those on the Long Island Sound shoreline. The beach is
all stone and cobbles, with three rock groins between the Orient Point ferry
slips and Orient Point. Orient and Long Beaches, west of the ferries, are also
fully exposed to Gardiners Bay. They form a long spit extending to the west-
southwest. The roadway was breached during the December 14, 1994 storm, and
now ltas in pieces under water. The roadway has since been rebuilt north of
its old location. The beach is a mixture of rock and sand, except at the pub-
lic bathing areas, where it is all sand. There are about 10 groins in various
state of repair along the beach, where the predominate direction of littoral
drift is from east to west. Long Beach Point is reported to change its orien-
tation from season to season. The spit protects Long Beach Bay, which is lined
with intertidal marshes. Long Beach Bay is not exposed to wave-generated ero-
sion, but some tidal currents have affected the shoreline. A channel was
dredged and then lined with bricks to give access around Peters Neck and Browns
Point. Although it has changed the circulation pattern, it does not seem to
have caused erosion.
Orient Harbor is an open bay, protected by Long Beach on the southeast and
Sheltar Island on the southwest from the waves of Gardinars Bay. Between the
end of Ring Street and Peters Neck Point, there are almost 20 groins along the
beach, where the predominate direction of littoral drift is to the south. The
predominate drift direction changes to the north near Ring Street. A number of
groins, bulkheads, and the Orient Yacht Club pier line the shoreline up to the
tidal marshes at the head of Orient Bay; the shoreline is then armored with
stone to protect the road. The land is less than 1,000 feet wide in this area.
At Dam Pond, there are only two thin strands of land, Truman Beach and Main
Road. The shoreline from Dam Pond to Spring Pond is lined with more than 20
groins and many bulkheads; the predominate direction of littoral drift is from
the northeast to the southwest. The mouth of Spring Pond is kept open by a
pair of Jetties. The shoreline from Gull Pond to Cleaves Point contains many
erosion-control structures. The Gull Pond Inlet was first dredged in 1959,
when 177,200 cubic yards of sand were removed. It is dredged about every 10
years; about 20,000 to 25,000 cubic yards of sand are removed. It is currently
kept open by jetties. Overall, Orient Harbor is heavily protected by struc-
tures. Although Oriant Harbor is only a little wider than 2 miles, wave action
is sufficient to be the main cause of erosion and beach movement. Tidal cur-
rents are important in shaping the shoreline around Peters Neck and Long Beach
Points.
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The stretch of coast from Cleaves Point past Gull Pond to Youngs Point is
well protected by Shelter Island and does not experience high wave action.
However, the shoreline is heavily protected with structures cf various types.
The direction of sand movement seems to be from east to west, but can be highly
variable. At the mouth of Gull Inlet, tidal currents predominate in the forma-
tion of shoals, both inside and just outside the inlet. These shoals act as
sink for the sand, removing it from the beach system.
REACH 6: FANNING POINT TO FOUNDERS LANDING
Pipes Cove spans Fanning Point to Conkling Point. Tucked behind Shelter
Island, the cove is about 5,000 feet wide. The two sides of the cove are pro-
tected by structures, and the head is the mouth of two creeks, Moores Drain and
drainage for Arshamonaque. There are tidal wetlands at the mouth of the creek
and freshwater wetlands farther inland. The beaches have been fairly stable,
overwashing during storms but building back fairly rapidly. The high developed
land along the east side of Conkling Point is protected by bulkheads for its
whole length, and almost 20 groins have been built along this area. Because of
the bulkheads and limited fetch to build waves, movement of sand is predomi-
nantly controlled by currents, although storms move sand depending on the wind
direction. The general direction of drift is north on the north half of the
shoreline and south on the south half. Gonkling Point itself has been accret-
ing sand and has expanded to the southwest.
The west side of Conkling Point, facing Brick Cove, is also heavily bulk-
headed with more than 15 groins. At the northwest end, the shoreline turns
toward an east-west orientation. There are dredged basins near the turn, which
were initially dredged in 1959 (163,900 cubic yards) and redredged in 1963
(129,200 cubic yards). They are protected by stone and metal jetties. Just
west of these basins, Mill Creek -- the entrance to Hashamomuck Pond and cur-
rently the entrance to the Port of Egypt marina -- has been dredged regularly
since 1963. The old entrance on the west side of marina at Budds Pond has been
closed off, and the offshore bar in front of Port of Egypt is maintained by
dredging. This area is open to waves from the south across Southold Bay, and
the fetch is about 10,000 feet, allowing for waves as high as about 3 to 4
feet. Storm waves and tidal currents at the mouth of the inlets have led to
erosion, but structures and dredging have been the major forces in shaping the
current shoreline.
At Budds Pond, there shoreline has a north-south orientation. The predom-
inate direction of littoral drift is to the south, and the shore is open to
waves from the east. These waves can reach 3 to 4 feet in height. The shore-
line is heavily bulkheaded with almost 20 groins, and the mouth to Bfexedon is
protected by two large jetties.
H. PEACH 7: FOUNDERS LANDING TO INDIAN NECK
The confluence of Town and Jockey Creeks at Harpers Point has complex
tidal currents and is exposed to waves from the east. The mouth of the creeks
has been dredged for many years, further complicating the situation. A shoal
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has protected the mouth for many years with the channel on the east side of the
shoal. The shoal is connected to the shore line, just north of the mouth of
Goose Creek, which is part of the tidal mouth complex. The east end of the
shoal was bulkheaded to prevant sand from depositing in the creek and to hold
the shoal in place. The bulkhead was destroyed in the December 1992 storm and
has not been replaced. The shoal has eroded, exposing Harpers Point to wave
action. The lee side of the shoal is next to the dredged channel into Jockey
Creek, and when waves overtop the shoal, sand is deposited in the channel. The
shape of the shoreline is controlled to a large degree by dredging and tidal
currents, but east winds, which cause westward traveling waves, contribute to
erosion of the area.
The north shore of Great Hog Neck is open to waves from a north and north-
east storm. The shoreline is heavily bulkheaded. Small boat basins have
dredged into Great Hog Neck. The predominant direction of littoral drift ap-
pears to be to the east. According to baymen, the tidal currents run east
during both the flood and ebb. This could be caused by a tidal gyre setting up
in Southold Bay. The tidal currents appear to be causing the elongation of
Paradise Point.
Between Paradise and Cedar Beach Points, Cedar Beach is open to waves
across Shelter Island Sound. The shoreline is bulkheaded and has about 20
groins protecting it. The shoreline appears to he eroding due to wave action.
However, some accretion is occurring around Cedar Beach Point, and the tidal
currents at Cedar Beach Creek form shoals around its mouth. The south shore of
Great Hog Neck is open to waves from the south across Little Peconic Bay, a
distance of 30,000 feet. Although winds from the south typically blow in the
summer and are usually low speed, the back side of a storm can cause high winds
from the south. The shoreline is bulkheaded and has more than 40 groins, espe-
cially towards the east end of this stretch.
Corey Creek ends the south side of Great Hog Neck, and Richmond Creek is
at the head of Hog Neck Bay. These form the apex of the bay, which is open to
waves traveling towards the northwest. Similar to the waves that affect Cedar
Beach, these are normally small, but the backside of storms can generate ero-
sion-causing waves. Corey Creek was first dredged in 1963-1964 (345,600 cubic
yards) and has been maintenance dredged regularly since. Richmond Creek was
first dredged in 1959 (123,000 cubic yards) and is regularly dredged. The
dredged materials have been used for various purposes and placed in different
locations. In January 1995, about 20,000 cubic yards was dredged and mounded
in the beach at Emerson Park. The dredged material was bulldozed into sur-
rounding vegetated areas to smooth it out. The bars at the mouths of the
creeks overwash during storms, but normally rebuild quickly. The tidal cur-
rents form shoals inside and outside of the mouths of the creeks. The dredging
and tidal currents are the major forces shaping the shoreline.
REACH B: INDIAN NECK TO DOWNS CKEEK
The shoreline curves around Indian Neck to a north/south orientation along
Little Hog Neck. This curve is interrupted by one inlet at Little Creek that
is dredged yearly. The shoreline from the public beach south to Nassau Point
is bulkheaded along its whole length with many groins. This shoreline is
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backed by a very steep bluff that quickly rises to more than 50 feet. This
bluff has eroded in places from groundwater seeps that are not associated with
coastal erosion. The fetch across Hog Neck Bay to Jeesup Neck is about 20,000
feet, and the waves come directly from the east. The direction of littoral
drift is very sensitive to wave direction and can reverse many times during a
year. According to baymen, the tidal current along this shoreline always sets
towards the south. Nassau Point seems to be elongating in response to littoral
drift and the tidal current.
The west side of Little Hog Neck is punctuated by two natural inlets for
Hog Creek and one dredged basin. The shore is open to waves from the south-
west, but Robins Island provides shelter. The coast is protected by a number
of bulkheads and groins. The shoreline is not as steep and high as the east
side. South of the Hog Creek inlets, the land rises to about 20 feet. From
the inlets north, the land is low lying. Meadow Beach, which is a Nature Con-
servancy preserve, is a small blunt spit formed by placement of dredged mater-
ials. The small boat channel between Meadow Beach and Little Hog Neck was
dredged, but has generally maintained its depth without additional dredging.
According to local residents, Meadow Beach has not eroded for at least the past
thirty years.
North of Meadow Beach spit, an inlet serves as the mouth of three creeks,
East Creek, Mud Creek, and Baywater/Broadwater Coves. This inlet was first
dredged in 1966 (434,000 cubic yards) and now is maintenance dredged every one
to two years. The beach on the west side lengthens to the east and into the
channel, requiring dredging. The channel used to run in front of Fishermans
Beach, but now runs straight out from the inlet. A large shoal, not attached
to the shoreline, has formed on the west side of the channel, and a smaller
shoal, attached to Fishermans Beach, is forming. The beaches on either side of
the inlet regularly overwash and flood the houses. The beaches have eroded
back about 20 feet in the past 20 years. The shoreline of Fleets Neck is ex-
posed to waves traveling west/northwest from little Peconic Bay. It is bulk-
headed, and the beach is primarily fashioned from placement of dredged mater-
ials. The bluffs behind the beach rise to about 50 feet.
Wickham Creek was first dredged in 1966 (48,300 cubic yards) and is now
dredged regularly. Between Wickham Creek and Schoolhouse Creek, the shoreline
is partially bulkheaded with heavier bulkheading towards Wickham Greek. This
shoreline is open to waves coming from the east across Cutchoque Harbor.
Schoolhouse Creek is dredged occasionally. Sand accretes in the vicinity of
New Suffolk Marina and the Robbins Island ferry slip, which is dredged yearly.
The groin for the New Suffolk point was recently rebuilt, and the New York
State Department of Environmental Conservation has installed a sand trapping
system.
The Town Beach is open to waves from the south coming across Great Peconic
Bay, a distance of about 37,000 feet. According to local residents, however,
the beach has not eroded, but has been stable. The shoreline is backed by a
low bluff. Based on the spit at Kimogener Point, littoral drift is general
from east to west. West Creek was dredged in 1966 (92,500 cubic yards) and is
dredged regularly. At least since the 1950's, the shoreline from West Creek to
Downs Creek has been eroding except when dredged materials have been placed on
it. Several deteriorating groins are located along this beach.
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J. PEACH 9: DOWNS CREEK TO THE TOWN LINE
The reach is fully open to the Great Peconic Bay, and the shoreline is
shaped by two large embayments or bights (gentle concave curve between two
points). The first bight is between Kimogener and Marratooka Points, distance
of about 6,000 feet, and the second between Marratooka and Brushs Points, a
distance of about 16,000 feet. Based on an open water fetch of 32,500 feet
across Great Peconic Bay, a hurricane force wind (75 miles per hour) can
generate waves up to about 4 to 5 feet high. This wave height is somewhat
limited because the bay is only 20 to 25 feet deep. The shallow water retards
wave growth.
Downs Creek is not regularly dredged and shoals form at its mouth. Place-
ment of dredged materials from Halls and Deep Hole Creeks provide sand, that is
then shifted by the wave and current action. Since the 1950's, six groins have
been built between Downs and Halls Creeks. Bulkheading started in the 1920's,
and the shoreline is now heavily bulkheaded. Halls Creek was first privately
dredged in the 1920's. In 1965, deep channels were dredged from Halls and Deep
Hole Creeks (243,000 cubic yards) to a joint channel about M-mile offshore.
The channels are maintenance dredged regularly with the sand placed on the
beaches. The spit in front of Deep Hole Creek is accreting towards the east,
indicating a west to east general littoral drift. Between the two creeks, two
deteriorated groins do not prevent erosion of the shoreline.
The shoreline between Deep Hole and James Creeks is heavily bulkheaded
with many groins. The predominate direction of the littoral drift is west to
east. The mouth of James Creek is protected by Jetties. When the channel was
first dredged in the 1940's, a layer of cohesive peat and clay acted as a jetty
to a certain extent. This layer has been eroded, and a shoal formed in the
channel, about 300 feet into the creek. During the 1950's when no jetties
existed, the eastern shore eroded back about 1,000 feet. In 1964 two Jetties
were built to stabilize the channel and the shoreline. As a result, the wes-
tern shoreline is about 1,000 feet bayward of the eastern shoreline at the
mouth of James Creek. The channel is dredged about every three years, and the
dredged material is normally placed on the eastern shoreline. The jetty on the
west is usually filled with sand. Between James and Brushs Creeks, the shore-
line is heavily bulkheaded with about 70 groins. Brushs Creek was first
dredged in 1966 (86,400 cubic yards) and is maintenance dredged regularly. The
dredged material is placed on either side of the inlet depending on the degree
of erosion. The shoreline between Brushs Creek and the town line is heavily
bulkheaded and has about 10 groins.
K. REACH lO: FISHEES ISLAND
Because of its location, land use patterns, and geology, erosion at Fish-
ers Island is very different from the rest of Southold. The island is mostly
elevated and rocky. Very few erosion protective structures have been built
along the shoreline. The south side of the island is exposed to Block Island
Sound, although the narrow opening at the Race acts as a constriction on the
wave energy striking the island. The cliffs have been eroded and only the
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largest stones remain in place. The beaches are made up of cobbles approxi-
mately 3 inches in size. This situation has minimized ongoing erosion. The
houses have been built on the cliffs and set back from the edges. Therefore,
erosion does not seem to cause problems on the south side of the island.
The north side of Fishers Island faces Connecticut, approximately 2M miles
across Fishers Island Sound. The north side of Fishers Island experiences much
lower wave energy. Most of the north side is also elevated and the houses are
not endangered by erosion. However, several houses in West Harbor have been
built in a low-lying area, and the home owners have built groins to protect the
houses. These structures have had some success.
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CHAPTEI~ III. C01~ON I{ANAGEI~ENT UNITS
A. INTRODUCTION
Although the Town of Southold's shoreline is highly variable and various
coastal processings are shaping different glacial landforms, certain commonal-
ities emerge. The natural common elements relate to wave exposure, proximity
to tidal inlets, bluff height and stability, and flooding. The human elements
include land use, lot size and shape, marine-related activity supported in the
area, and already constructed erosion measures. When these factors are com-
bined, they form common management units where certain coastal processes are
dominant, and certain erosion protection policies are most applicable. Figure
III-1 presents the common management units. On the Peconic Bay shoreline,
these units overlap, and more policies need to be considered. Particularly on
the Peconic Bay side of Southold, the boundaries are not definitive, and fur-
ther study is required to precisely characterize the unit and define its
boundaries.
B. LONG ISLAND SOUND COAST
Three common management units make up the Long Island Sound coast of
Southold; these are: areas directly affected by the two Jetties, areas of low
bluffs and dunes, and areas of high bluffs. These features are shown in Figure
II-3 and II-4.
JetL-yAreas
The Jetties at Mattituck and Goldsmith Inlets dominate the coastal pro-
cesses and responses in the area. The direct effects of Mattituck Inlet are
felt about i mile tv the west and about N of a mile to the east,. On the west,
sand has been trapped by the jetty, and the shoreline has built out. The west
Jetty is close to completely full, and sand is being lost, either offshore or
into the channel. As long as the Jetty is functioning, the west side of Matti-
tuck Inlet will be protected from erosion. However, sand that would help ero-
sion on the east side of the jetty is being lost into the channel and offshore.
III-1
LONG ISLAND SOUND
IS~ND
PLUM
ISLAND
LITTLE
" PECONIC
NE'&SUFFOLK
~ BAY /'
~S ~ ~ SPRINGS
I~ ~ ~OYACK
0 2 MILES
Long Island Sound
"'"'"'"'"' High Bluff
Peconic Bay
Creek Mouth
........... Exposed Area
Figure II1-1
,,,,,,,,,,,,,,,,,,,,,, Low Bluff ~ Protected Area
............ FIoodPro.e Common Management Units
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The east side of the jetty has experienced severe erosion and loss of
dunes. As discussed in Chapter I, these dunes act as sand ~banks;" during
severe storms, sand is withdrawn and used to help the beach recover. The two
jetties and the channel intercept the flow of littoral drift and hold the sand
on the west side of the inlet. The eastern shoreline has recovered to some
degree, but not completely. The major factor limitin~ the downdrift erosion is
the presence of Oregon Hills, which acts as a l~. ~nd source feed~n~ the
beaches further downdrift.
The beach between the east jetty and Oregon Hills has eroded because of
the lack of sand. Some sand has been added to the beach, both by natural by-
passing and some human activity. The beach has responded by flattening its
slope. This means that the added sand has not moved the normal high water line
further seaward, but that the sand is being deposited just offshore, creating a
shallow beach. The sand is slowly filling the area behind the jetty. This
process does not rebuild the dunes until the triangle of sand in the shadow of
the jetty is exposed to the air where the wind can blow the sand landward. At
the current rate, dunes will not start re-forming for many years.
The jetties at Goldsmith Inlet do not have an updrift effect as large as
at Mattituck, primary because they are shorter. The__qpdrtft influence is about
The downdrift effects have been greater because of the low elevation
of the land. Unlike the high bluffs of Oregon Hills, Horton Lane Beach is low
lying with a bluff located well inland of the water line. The effects of Gold-
smith Inlet jetties are felt ~9; mmv. ~- 1~ m~l~. dn~v~ft. Horton Lane
Beach regularly erodes and requires replenishment.
Erosion protection policies are discussed in the next chapter, but the
major factor in applying them in the vicinity of the jetties is the effect on
the downdrift side, which is threatened by erosion. Methods should be applied
wherever possible to have the sand by-pass the Jetties. This by-passing has
the double advantage of preventing sand from being lost offshore and supplying
it immediately to an area prone to erosion.
Areas of Lov Bluffs and Dunes
Areas of low bluffs and dunes include Horton Lane Beach (discussed above),
Hashamomuck Beach, and Pettys Bight. These areas are characterized by the lack
of high bluffs next to the shore. The bluff can be inland or non-existent.
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Some dunes may be found behind the beach. In Pettys Bight, the bluff is gener-
ally less than 20 feet high. To a certain degree, these areas also coincide
with small building lots. These lots do tend to be narrow and deep, allowing
houses to be set back from erosion danger.
The dunes are the only place on Southold's Long Island Sound coast where
flooding occurs landward of the shoreline. Excluding the jetties at the two
inlets, few shore protection structures are found on Southold's Long Island
Sound coast, but they are found along these areas. Each of the structures has
been built to protect a single lot or a small area, and no overall plan has
been developed. Along the areas of low bluffs and dunes, s~d
Rnl¥ be allowed when a house is in dan~er, and no othmr a~ternative will save
the house. One alternative to be considered entails moving the house. The
policy recommendations in the next chapter for set backs and native seaside
vegetative plantings are especially applicable in these areas.
Axeas of H~,h Bluffs
High bluffs constitute much of the Southold's Long Island Sound coast.
The bluffs are from 40 feet to nearly 100 feet high and consist of unconsol-
idated sediment. The sediment ranges from sand and gravel to huge boulders.
These bluffs are the source of much of the sand and gravel that form Southold's
beaches. Therefore, they are very important in slowing the erosion of the
shoreline.
Few erosion protection structures are currently found in the areas of high
bluffs. The lack of structures has allowed the shoreline to erode very slowly,
and natural headlands, such as Morton Point, to emerge. If hard structures are
built in these areas, this dynamic would change. The hard structures would try
to become the new headlands. I~is very likel~ that th~ structures would cause
an overall increase i~_the rate of ero~on as the shoreline tries to come into
e qui~ib r ium.
A problem on bluffs in the presence of clay lenses. The only area with
large__is Pett~s Bight (a low bluff area), but some are also found
in the high bluffs. Clay layers can cause erosion of the bluffs. The clay
tends to be impervious to water, and the water migrates along its upper sur-
face. If a large source of water, such as a septic system for a restaurant, is
located above the clay, the water will flow out to the bluffs. This creates a
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wet area where internal pressure from the water can be greater than the fric-
tion holding the sediment together. When this happens, the sediment slips and
the bluff slumps.
C. PECONIC BAY SIDE OF SOUTHOLD
The coastal dynamics of the Peconic Bay side of Southold are more varied
than the Long Island Sound side. As described more fully in Chapter II, many
inlets, marshes, varying wave exposures, and opposing tidal currents character-
ize the shoreline. Generally four common management units emerge: creek
mouths; wave exposed shorelines; wave protected shorelines; and flood prone
areas. Certain locations may have two of these characteristics, and therefore
policy decisions will involve weighing the management objectives. An example
is Fishermans Beach, which floods regularly and is at the outlet of three
creeks.
Creek l~)uths
Creek mouths act as a funnel for tidal currents, speeding the water flow
and carrying sediment in and out of the creeks. When the current reaches the
wider areas inside and outside of the mouth, the current slows down and some of
the sediment is deposited. These deposits form the shoals around the creek.
Almost all of the creeks are used for navigation, and the shoals need to be
dredged to provide sufficient navigation depth. The dredging and use of the
dredged materials is the key management objective in these areas. This dredged
sand is a valuable resources that needs to he used wisely to prevent erosion
and to build beaches. The most beneficial use of the sand varies from inlet to
inlet, and will vary at the same inlet in different years. The storm direction
and its attendant waves change; one storm moving sand to the east, and the next
moving the sand to the west. Each decision concerning where to place the sand
will depend on the storm pattern that most recently affected the inlet.
Within this management unit, the length of jetties to stabilize the inlets
is important. At Mattituck Inlet, the west jetty is 200 feet long while the
east jetty is 50 feet long. This length has stabilized an offset inlet with
the west side seaward of the east side. The east side erodes and requires
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periodic beach fill while the west side has trapped all the sand that it can
hold. When jetties are proposed, careful thought about the relative length and
placement is required.
E~posed Shores
The Peconic Bay Side of Southold has several shores exposed to waves com-
ing across Great Peconic Bay, Hog Neck Bay, and Gardiners Bay. For the most
part, these shorelines have been heavily protected with bulkheads and groins
(see Figure II-6). The low lying nature of some of the shoreline and easily
eroded sediment in the bluffs led to the early use of erosion protection struc-
tures. Because so much of these shores have been protected by erosion-control
structures, 'the few remaining unprotected lots are eroding. Therefore, it
would be very difficult to refuse permission to one homeowner to protect the
property when all the surrounding houses have bulkheads. However, standard
designs can be developed that will minimize effects on updrift and downdrift
properties. Groins are particularly important and should be thought of as
groin fields, not as individual groins. When a groin field is designed as a
whole, specific lengths, heights, angles, and spacing can be developed so that
all of the groins act as a unit and provide the most benefit to all of the
homeowners.
Protected Shores
Protected shores include Hallock Bay, Pipes Cove, Conkling Point, and
parts of Southold Bay and Cutchoque Harbor. These areas are also heavily pro-
tected with bulkheads and some groins. Flooding has led to most of the bulk-
head construction so that a house can be raised above the flood plain. In
these areas, the granting of permits should not be automatic, especially for
groins. Wave action is not the major cause of erosion, but groins can exacer-
bate the effects of waves. The problem that the structure would solve should
be clearly defined and the use of non-structural measures analyzed. In many
cases, beach filling can solve or at least ameliorate the problem.
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Flood l~one Areas
Many areas on the Peconic Bay side of Southold are flood prone. The prob-
lem with flooding is not the flooding itself, which is an inconvenience, but
the damage to houses and property. The traditional method of preventing dam-
age has been to protect them with bulkheads. This raises the ground out of the
floodplain. Another method used in other areas consists of building the house
on piles with the bottom of the floor above the floodplain. When a flood oc-
curs, the water goes under the house but does not damage it. While this method
would not work for existing houses already protected by bulkheads, it would
work for new houses.
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CHAPTEK IV, PROPOSED EROSION 14ANAGEHENT POLICIES
Southold's shoreline is more than 26 linear miles long, and when the em-
bayments, inlets, and spits are included, the coast stretches to more than 163
miles. This diverse shoreline attracts a wide variety of human and natural
activities. Almost 1,000 acres of protected tidal wetlands and more than 1,400
acres of shellfish beds are encompassed in this coastal area. Miles of beaches
and shore parkland attract visitors and residents. Homes and summer houses
line the shore. Marine businesses, including fishing, shell fishing, transpor-
tation, recreational boating, and construction, are vital to the economic well
being of Southold and its residents.
To stabilize and protect these shores for human uses, myriad structures
have been built over a period spanning many years. These include groins, Jet-
ties, bulkheads, and revetments. To improve navigation for both business and
pleasure, channels have been dredged through the inlets, and the dredged mate-
rials used to make new land or added to beaches. Each construction project
took place with a view to achieving its own goals, whether protection of one
landowner's beach or the creation of a navigable channel for a particular mari-
na. These projects were often undertaken without regard to the overall effects
on the coastal processes. The dredging and building of Jetties at Mattituck
Inlet have served the marina businesses and boaters well, but have led to loss
of beach east of the inlet. One of the main purposes of the coastal erosion
policies is to ensure that the consequences of building an erosion control
facility are understood before the structure is constructed.
Erosion control structures often contribute to erosion both on- and off-
site due to poor design and siting. Increased erosion, aesthetic impairments,
loss of public recreational resources, loss of habitats, and water quality
degradation can result from poorly placed or designed erosion control struc-
tures. The cumulative impact of a number of individual structures can be even
more damaging. Therefore, the purpose and function of erosion control struc-
tures must be defined, and the consequences and potential impacts, both on- and
off-site, need to be analyzed, before permission is granted for building a
structure.
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As discussed earlier, the number and type of erosion control structures
differ greatly between the Long Island Sound and the Peconic Bay shores. On
the Long Island Sound shore, few structures have been built and bluffs back
almost all of its length, preventing flooding. The Peconic Bay coast has been
hardened by many structures, and long lengths of it are low in elevation and
prone to flooding. Therefore, proposals for erosion control structures on
these two shores of Southold need to be evaluated separately.
The Long Island Sound shoreline generally has few structures and the
houses are well above flooding elevation. Hard engineering solutions should be
discouraged, and where erosion has recently become a problem, such as Pettys
Bight, a soft solution should be encouraged. The soft solutions include set-
backs from the top of bluff, setbacks from the high water line, natural vegeta-
tive buffer, and beach restoration. In areas of high public use, such as
ton Lane Beach, beach filling should be used to maintain the recreation values.
If erosion threatens property downdrift of the two sets of jetties, sand by-
passing or off-shore mining of sand should be considered.
With the existing heavy construction along the Pecontc Bay shore, rebuild-
ing of existing structures and building of new structures will be required into
the foreseeable future. Unprotected properties could erode and be subjected to
damaging floods. However, permits should not be granted automatically. Before
granting a permit, sound engineering analysis of the effects of the individual
structure within the surrounding structures, such as whole groin fields, is
necessary. Soft solutions, such as the use of dredged materials for beach
fill, should be the preferred approach and always included as an alternative.
The soft solutions' inability to achieve the structure goals must be demon-
strated before granting permission for the structure.
For both shores of Southold, whole reach or length of similar processes'
analyses should be required. Consideration must go beyond a single structure
or a single piece of property, and the effect of updrift and downdrift on prop-
erties should he evaluated. As discussed in Chapter V, removing and rebuilding
whole groin fields should be considered. This approach would go beyond amelio-
rating a single person's problem. Further, by considering whole groin fields
at a time, an entire community's problem would be addressed.
Appendix A contains the text of Policy 5 Minimize loss of life, struc-
tures, and natural resources from floodinf and erosion from the Long Island
Sound Coastal Management Plan. The proposed Policy 5 of Southold's Local Wa-
terfront Revitalization Plan follows the same format. The following section
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in the low bluff and dune areas on Southold's Long Island Sound coast. The
flood plain management requires that habitable space be located above the 100
year floodplain. On the Peconic side it is recommended that the code specific-
ally include building on ~iles rather than ustn~ bulkheads. For the property
owner, raising the building rather than the ground would be less expensive. A
bulkhead that could affect nearby neighbors would not be required.
The hierarchy to erosion control measures given above has not been
adopted, and it is recommended that it be included in the application require-
ments for a waterfront construction permit. Each applicant would have to
demonstrate why the structure cannot be located outside of a flooding or ero-
sion area; why vegetative or other non-structural measures would not protect
the applicant's property; and why natural protective features are not suffi-
cient before a permit could be granted. Thes~e measures should be included in
both the Board of Trustees hv-l~ws and in the Town of Southold Building Code.
As discussed in Chapter III, using this hierarchy is particularly important on
Southold's Long Island Sound high bluff areas and needs to be seriously consid-
ered in all low bluff areas.
Specifically, Section 100-239.4 of the Town Code should be amended so that
the set back be 150 feet from the top of bluff or mean high water, whichever
is more landward, on the Long Island Sound side. The same distance should be
used on the Peconic Bay side where the shore has not been bulkheaded. Addi-
tionally, natural vegetation cannot be removed beyond 75 feet from the top of
bluff or mean high water, whichever is more landward. The only exceptions
include accessory structures for .changing clothing, and less than 100 square
feet that could be located between the 75-foot vegetative buffer and the 150-
foot setback.
Hatural Protectiwe Features
5.4 Policy to protect and restore natural protective features
Natural protective features, such as bluffs and dunes, are found through-
out the Town and must be protected to minimize erosion and flooding. The Town
of Southold should adopt the same definition of natural protective features
found in New York State regulations. They specifically include the nearshore
area, beaches, bluffs, primary and secondary dunes, wetlands, and natural vege-
tation. The alteration of natural protective features "might reduce or destroy
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the protection afforded other lands against erosion or high water, or lower the
reserves of sand or other natural materials available to replenish storm losses
through natural processes.# It is recommended that these be added to the zon-
ing code, along with a prohibition on removing or lessening natural protective
features' effectiveness, without a permit from the Town.
Policy to Protect Public and Public Trust Lands
5,5 Protect public lands and public tr~st lands and use of these lands when
undertaking all erosion or flood control projects.
Parts of Southold's shoreline are in public ownership and other parts,
such as~ea~ow Beach Preserve are held by the Trust for Public Lands (Trust), a
private organization that holds and protects ecologically valuable land. Those
areas of shoreline in public ownership must be kept for use of Town residents
and visitors. The Town should work with the Trust to preserve valuable natural
lands, such as marches and wetlands. The Trust will often set up trades where
a developer will deed a valuable natural site to them in return for another
site that would be easier to develop. This private sector entity can raise
funds to protect natural protective features and ecologically significant
sites, where the Town could not. By working with the Trust, the Town would
have an instrument to direct development and protect sites on a smaller scale
than can normally be achieved through zoning or other regulation.
Policy on Water-Dependent Uses
5.6 Site Water-dependent uses and manage navigation infrastructure to limit
adverse impacts on coastal processes.
On the coast line exposed to erosion, the majority of the sites are either
in public or residential hands. Marinas and other water-dependent users tend
to locate in the protected creeks on the Peconic Bay side and in the two inlets
on the Long Island Sound side of Southold. On the Long Island Sound side,
three sites are zoned resort/residential and one site zoned MII. The MII site
is no longer used and an undermined ramp remains from a fishing station. On
the Peconic Bay side, Orient Point is zoned MII for the ferries. Areas zoned
as marinas are located in Orient Harbor, Cleves Point, Mills Creek area (2),
Town Creek, and New Suffolk. Four areas zoned resort/residential are also
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found on the Peconic Bay side. Fishers Island contains two MII zones, and the
rest of its shoreline is zoned residential. The marine-zoned areas should
allow only water-dependent uses, such as marinas, fishing stations, and boat
repair yards. The areas zoned resort/residential should be encouraged to de-
velop as commercial ventures with public access. Residential use prevents
public access, and many resort type uses, such as conference centers and res-
taurants, provide water-enhanced experiences for the users.
Policy on Expenditure of Public Funds for Erosion Control
5.7 Expend public funds for management or control of flooding or erosion only
in areas of the coast which well result in proportionate public benefit.
Although most of the property that is threatened by erosion is privately
owned, protection of that property is in the public's interest. However, the
public benefits must be carefully weighed when considering expenditure of pub-
lic funds. Within the jetty areas on the Long Island Sound side of Southold,
the federal government is making large expenditures to protect navigation for
fishing and commercial fleets, as well as for some recreational boating. The
U.S. Army Corps of Engineers have made detailed benefit cost analyses and have
found that the benefits outweigh the cost. However, the use of the drmd~md
mater~ials and the cost of installing a sand bypass system need to be investi-
g~ed. ~ sand bypass system could speed the recovery of the beach on the east
side of the-inlet, leading to more public use of the area with its tourist
benefits. The sand bypass system would also reduce the cost of dredging be-
cause the sand would no longer move around the end of the jetty and deposit in
the channel; it would be bypassed and deposited on the beach. The same anal-
ysis is needed for Goldsmith Inlet.
On the Peconic Bay side, the same analyses should be done for dredged
materials from creek mouths. Suffolk County bears the cost of this dredging,
and the greatest public benefit should be derived from that expenditure. The
analyses to date have focused on the navigational aspects, and the erosion and
erosion protection benefits have not been fully included. On the exposed
areas, the cost of developing the approach to gin field design wm~ld bring
public benefits. Existing erosion problems could be solved or ameliorated, and
future problems avoided. Groin fields covering whole lengths of shoreline
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could be laid out and their height, length, and spacing specified. This ap-
proach would benefit all owners sharing a given part of the shoreline, not just
one property owner.
Policy on Limiting D-m-ge in the Coastal Area
5.8 Limit potential loss of life and structural damage in all development in
the coastal area.
Many of the residences and buildings on the Peconic Bay side of Southold
are subject of water damage and flooding. The building code recognizes these
dangers and has incorporated the applicable standards from the Federal Emer-
gency Management Agency and the Uniform Building Code. These standards need to
be vigorously enforced. As discussed above, the use of pile supported struc-
tures, rather than building bulkheads, would limit structural damage without
the drawbacks of bulkheads.
In addition, the amount of debris that can break loose during a storm
needs to be limited. The Town Code should have a r~uiremeqt for
and cleaning up debris after a stor~_. This includes walkways, docks, piers,
and other structures that were dislodged during the storm. These materials
could cause further damage to other buildings, especially if a second storm
closely follows the first.
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CHAPTER V. POST STORH RECOFERY POLICIES
A, POST STORlt RECOVERY
Tntroduct ion
The common tendency after a damaging storm is to return to the same situa-
tion as before the storm, whether or not that situation was desirable. The
post storm rebuilding should be aimed at preventing and minimizing erosion and
flooding. The approach will vary by the type of damage inflicted by the storm
and by the goals of each of the common management units. In addition, the
permitting procedures may constrain or delay certain actions in the rebuilding
process. This chapter discusses the approach to be taken in each of the common
management units, and how existing permitting procedures may be used to achieve
the goals of the units.
Post Storm Recovery Goals by Com~c~ M=-=gement Unit
Long Island Sound Side
On Southold's Long Island Sound coast, the major cause of damage during a
storm is wave action leading to erosion of the bluffs and loss of the dunes.
The storm could also seriously damage the jetties at Mattituck and Goldsmith
Inlets. Inundation of large inland areas does not typically occur.
Jetty Areas
A storm could flank the jetties, causing the inlet to migrate out of its
present channel. In this case, the flanked area should be filled so that the
protected channel is returned. A migrating channel could lead to erosion of
previously protected property and instability in the inlet.
The storm could seriously damage or destroy the Jetties. If Mattituck
Inlet jetties are destroyed, they should be rebuilt. The economic hardship on
businesses in Mattituck Inlet would be unbearable, and they would either relo
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cate or close~ In either case, Southold would lose jobs from its economic base
and part of its maritime tradition. Therefore, rebuilding of the jetties to
protect the inlet and its uses should be done as quickly as possible.
For Goldsmith Inlet, the decision is not as straightforward. The original
purpose of the jetties -- a public park -- is no longer envisioned, and the
jetties are causing erosion along Horton Lane Beach, which is heavily used by
the public. Serious study and consideration should be given to removal of the
jetties if they are destroyed or damaged during a storm. The effects on the
downdrift beaches need to be analyzed prior to making this decision. The wa-
ters that are now drained by the inlet would become formally connected tidal
wetlands that have their own unique habitat value. Ways to protect these wet-
lands and to prevent them from becoming a public hazard or nuisance would have
to be developed. Based on these studies, the most beneficial course of action
in the case of heavy damage to the jetties can be selected.
The final situation around the jetties is severe erosion of the downdrift
beaches and loss of dunes. In both areas, the beach should be refilled with
sand, from the updrift side of the jetties if possible. These beaches are
valuable and heavily used by the public. The beaches would accrete sand slowly
after being damaged, but this could lead to further downdrift erosion because
of the lack of sand. Therefore, refilling the beach is warranted. At Mattl-
tuck Inlet, the erosion of the beach could also cause a breach, and the inlet
would migrate to outside of the current channel. The new channel would proba-
bly not be navigable by the fishing boats and could cause the same type of
dislocation as loss of the jetties.
Low Bluffs and Dunes
During large storms, the waves erode the bluffs at their toe, which leads
to slumping. The slumping brings some new sediment to the beaches. The damage
is normally loss of bluff and encroachment into a yard area. This excludes
those cases where the principal residences are endangered, as is discussed
below under Emergency Procedures. In the dune areas, flooding often occurs
during the storm, eroding the dunes and causing water damage to personal
property.
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The management objective in the low bluffs and dunes common management
areas is to reduce the number of hard erosion protection structures and en-
courage soft approaches, such as vegetative cover. However, existing struc-
tures that are either grandfathered or permitted can be rebuilt as-of-right.
Some of the erosion protective structures will undoubtable be rebuilt almost
immediately.
However, the Town and the Board of Trustees' focus here should not be on
rebuilding everything immediately -- including erosion protection structures --
but on how the current damage to homes can be corrected and future damage mini-
mized. Applications for new structures should be carefully reviewed rather
than granted quickly. The effects of new structures on surrounding properties
must be shown by the applicant. If a permit is granted, the conditions should
include meeting the setback requirements for the principal structure and the
full width of native vegetation planting. The construction work, if permitted,
would have to include meeting these requirements and not be done at a later
time.
As part of the rebuilding, the Buildings Department needs to examine the
condition of the house and its likelihood of being damaged again in the next
storm before issuing its permit. If a house could be damaged in the next
storm, the owner should be required to rebuild it so that the damage would not
occur again. This could include moving the house further away from the shore-
line or installing a new foundation. In a dune area, raising the house above
the flood area would be appropriate.
Areas of High Bluffs
The toe of high bluffs is eroded during a storm, and then the bluffs slump
down because of the lack of support. The slumping of the high bluffs supplies
large volumes of sand and gravel to the beaches. Each linear foot of a 50-
foot-high bluff supplies about 2 cubic yards of sediment for each landward foot
of erosion. These bluffs are of great importance in maintaining the beaches
and protecting the areas of low bluffs and dunes, which are more susceptible to
landward erosion that threatens homes. The management objective of this common
management unit is to prevent the building of groins and erosion protection
structures to the extent possible, without causing loss of property. There-
fore, the post storm recovery approach should be the same as during the normal
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permitting process; the overwhelming need for erosion protection structure must
be demonstrated by the applicant before a permit is issued. Emotional appeals
of the property owners who feel their lands are in danger can be persuasive,
but the overall needs of the shoreline must be considered first. Measures,
such as planting vegetation along the shoreline, must be analyzed first, and
the permit for an erosion protection will be issued only when such methods are
shown to be infeasible.
Peconfc Bay ~de
On the Peconic Bay side of Southold, where almost all of the shoreline is
heavily protected, the focus of post storm recovery policies is to focus on
segment or reach long analysis, rather than on individual structures. If a
whole length of similar shoreline is considered as one, solutions that protect
all property owners can be developed and implemented. The aggregate cost for
protecting a whole length of shoreline will probably be less than the sum to-
tals that the property owners would pay.
While the Town and the Board of Trustees do not have the direct power to
cause a group of properties to act in concert, the post storm review process
can lend itself to this approach. If a group of neighbors submitted a joint
application, the effects of the proposed structures on neighbors would already
have been demonstrated, whereas if a single property owner submits an applica-
tion, the effects of the proposed structure on neighbors would still need to be
demonstrated.
Using this group approach would help achieve the management objectives in
all co--on management units on the Peconic Bay shoreline, except for flood-
prone areas. These areas have an additional goal of preventing further flood
damage. Therefore, the Buildings Department should not issue permits unless
flood-proofing can be demonstrated. As discussed above, raising the building
on piles rather than raising the land behind a bulkhead is the preferred
approach.
Emergency Permits
The above recommendations apply when a structure is not in imminent danger
of collapse or significant structural damage. Certain storms will cause damage
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that must be repaired under emergency conditions. Homes and principal resi-
dences must sometimes be immediately repaired or they will collapse or become
permanently damaged. This can be caused by falling trees, trucks striking the
house, and coastal erosion. An emergency situation for a house or principal
residence is often defined as when 25 percent of the floor area is close to
collapse or permanent structural damage as certified by a professional engineer
or licensed architect. This is a situation that is handled by the Buildings
Department, and they have proper procedures in place.
Shore protection structures can generally be mended temporarily while a
decision on the type and extent of the final restoration is being made. The
heavy construction materials and type of structural supports make this delay
possible. An existing erosion protection structure that is properly permitted
or grandfathered can be repaired without a permit. However, many groin fields,
especially on the Peconic Bay shoreline, are not truly functioning structures.
Therefore, if erosion control structures are being emergency repaired, the
building inspector or an independent should inspect the site and certify that
it was an a functioning structure. If the structure was not functional, the
work should be halted. As discussed in Chapter VI, "Implementation Options,"
an inventory of functioning structures should be mapped and photographed in the
future. Trying to determine if a structure was functioning after having been
damaged is likely to lead to disputes. This inventory would address that
issue.
The only true emergency situation that would require a discretionary per-
mit is when the sole public access to a group of houses is about to be de-
stroyed or when a vital public utility, such as water or electricity, is about
to he severed. Then, the only way to protect the sole access or utility from
the next storm would be to build an erosion control structure. In cases such
as this, the State Environmental Quality Review Act (SEQRA) lists the action as
exempt, and the New York State Department of Environmental Conservation (DEC)
has emergency procedures for permitting under its regulations. The Corps of
Engineers has similar procedures. Therefore, an emergency permit should only
be issued for protection of sole access ways and vital utilities, and existing
regulatory emergency procedures should be used.
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CHAPTE~ VI. IMPLEMENTATION OPTIONS
A. IMPLEMENTATION OPTIONS
S~udies
Because of the breadth and variety of Southold's shoreline, the recommen-
dations contained in this report are general in nature. To fully implement
these recommendations, detailed study of each of the reaches and common manage-
ment units is recommended. The scope of work for the first reach -- Duck Pond
Point to Horton Point -- has been developed, and the study is to begin as soon
as funding is available.
Another important task that can be done almost immediately is to develop
an inventory of functioning erosion protection structures. Functioning coastal
erosion structures that are damaged in a storm can be repaired without a per-
mit. As part of the post storm recovery approach, restrictions on rebuilding
erosion control structures have been recommended. At the current time, no
inventory of functioning structures exists, and disputes could arise if post
storm judgements are made on the functionality of structures. This inventory
should mapped, photographed, and videotaped; it will be important in the imple-
mentation of this post storm recovery policy.
The Jetties at Mattituck Inlet have caused downdrift erosion and have
threatened the dunes between the inlet and Oregon Hills. However, the commer-
cial and recreational uses in Mattituck Inlet are an essential part of the
character and economic life of Southold, and the jetties are necessary for
navigation. A sand bypassing could address the erosion problem and reduce the
expense of dredging the channel. A study of the feasibility and cost of a sand
bypassing system is recommended.
In Chapter V, "Post Storm Recovery Policies," the problem of rebuilding
the jetties at Goldsmith Inlet if they are damaged in a storm was discussed.
These jetties have led to erosion at heavily used public beaches. The effects
of removing the jetties and closing the inlets could be studied prior to a
damaging storm, forcing a decision without sufficient study. This particular
study would rely on the findings of the detailed reach study of Duck Pond Point
to Horton Point.
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Cap~ta~ l~ojects
Without the studies discussed above, no capital projects can be recom-
mended at this time. Prior to committing to capital development, the public
benefits need to be more firmly established and the costs estimated in detail.
Southold could implement several demonstration projects with its own resources.
These include a natural vegetation nursery to determine which plantings do well
and provide the best erosion protection. The Town could erect sand fencing,
such as DEC is doing at New Suffolk, on public dune areas.
Long-Term Coordination
Two long-term coordination with the state level of government will benefit
the Town of Southold. The first is the current coordination with the Division
of Coastal Resources and Waterfront Revitalization in the Department of State.
This division has been providing important guidance and funding to Southold for
the development and protection of the coastal area. This relationship should
continue.
The second long-term coordination is with Suffolk Gounty and DEC for the
use and placement of dredged materials. Thousand of cubic yards of sand are
dredged every year on the Peconic Bay shore, and Southold has had little, if
any, input into the placement of that sand. The dredged material is a very
important resource that can address many of the erosion problems in the creek
mouths and along the exposed shoreline. A three-part committee should be set
up to review the upcoming dredging projects and decide where to place the sand.
These decisions will have to made yearly because the erosion patterns change
based on the direction and severity of the storms. This committee could be the
most important tool available to Southold for use of the dredged materials to
alleviate its erosion problems along the Peconic Bay shores.
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COASTAL ENGINEERING GLOSSAI~Y (FROM SHORE PROTECTION MANUAL, 1984)
A¢CP~ETION. Buildup of land on a beach either by action of the forces of nature
or an act of man.
AKOT.TAN SANDS. Sediment of sand size or smaller that have been transported by
winds.
ALONGSHORE. Parallel to and near the shoreline (LONGSHOP~).
AP~ORDNIT. Relatively large quarrystone or concrete shape that is used for
wave protection structures.
A'r£zNUATION. The lessening of the amplitude of a wave with distance from the
origin or through structural or landform interference.
BAGKSHORE. Zone of the shore or beach lying between the foreshore and coast-
line. Acted on by waves only during extreme storm events.
BA,~. Submerged or emerged embankment of sand, gravel, or other unconsolidated
material built on the sea floor in shallow water by waves and currents.
BAP, HIE~ BEACH. A bar parallel to the shore, the crest of which is above normal
high water level.
LAGOON. A bay separated from the open ocean by barrier islands.
The measurement of depths of water in oceans, seas, and lakes.
BAYffOUTM BA~. A bar extending partly or entirely across the mouth of a bay.
BEACH. The zone of unconsolidated material that extends landward from the Iow
water line to the place where there is a marked change in material of
physiographic form, or to the line of permanent vegetation. Consists of a
FORESHORE and BACKSHOP~.
BEACH BEP~. Nearly horizontal part of a beach or backshore formed by the depo-
sition of material by wave action.
BEACH ~OSION. The removal of beach materials by wave action, tidal currents,
littoral currents, or winds.
BEACH FILL (NOURIS~NT). Material placed on a beach to renourish an eroding
beach, or the act of beach replenishment either naturally or artificially.
BEACH P~OFILE. The intersection of the ground surface with a vertical plane;
may extend from the top of the dune line to a seaward limit of sand
movement.
BEACH SCARP. An almost vertical slope along the beach caused by erosion due to
wave action.
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BEACH ~IDTH. The horizontal dimension of the beach measured normal to the
shoreline.
BLufF (ESCA]~n~T). A high steep bank or cliff.
BBP~F-F~R. A wave breaking on a shore, over a reef, etc.
BBF~k'~A'I'~J~. A structure protecting a shore area, harbor, anchorage, or basin
from waves.
BUL~M~B. A structure that retains or prevents sliding of the land, and pro-
tects the upland from wave action.
BYPASSING, SAND. Hydraulic or mechanical movement of sand from the accreting
updrift side to the eroding downdrift side of an inlet or harbor entrance.
CWaRT (TIDAL) DATUI~. The plane or level to which soundings, elevations, or
tide heights are referred.
COAST. A strip of land of indefinite width that extends from the shoreline
inland to the first major change in terrain features.
COASt. Line separating the coast and the shore; more commonly, the boun-
dary between land and water.
~. A flow of water, typically generated by wave action, tidal fluctua-
tions, or winds.
CUSPATE BA~. A crescent-shaped bar uniting with the shore at each end.
DECAY ON ~AVKS. The change waves undergo after leaving a generating area and
passing through a calm or region of lighter winds.
D~P ~Ax~. Water deep enough that waves are not affected by the ocean bottom.
DEFLATION. The removal of loose material from a beach or other land surface by
wind action.
DEI~I~t. The vertical distance from a specified tidal datu~ to the sea floor.
DAF~SACTION. The phenomenon by which energy is transmitted laterally along a
wave crest. In a coastal sense, it occurs when a wave train is inter-
rupted by a structure or seafloor elevations differences in such a way
that waves are propagated into the sheltered region of the structure.
DIUBIqAL TIDE. A period or cycle of approximately one tidal day.
DO~IqDB.I~. The direction of predominant movement of littoral materials.
DU~ES. Ridges or mounds of loose, unconsolidated material, usually sand.
~q~q~E/Tf. An indentation into the shoreline forming an open bay.
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ESCAPA~T. A line of cliffs or steep slopes facing in one general direction
that are caused by erosion or faulting.
ESTUARY. Portion of river that is affected by tides or region of a river mouth
in which fresh and salt water mix.
~A'£KAT]IOPI~AL STOP~. Storms that develop in the mid-latitudes in response to
the interaction of warm and cool air masses, commonly referred to as
northeasters.
FETCH. The area in which seas are generated by wind having a fairly constant
direction and speed. The horizontal distance (in the direction of the
wind) over which a wind generates seas.
FORESHORE. The part of the shore lying between the crest of the seaward berm
and the ordinary low-water mark.
GKO~O~,.I:'HOLOGY. That branch of both physiography and geology that deals with
the form of the earth, the general configuration of its surface, and the
changes that take place in the evolution of landform.
Rate of change with respect to winds, currents, or wave heights.
GROIN. A shore protection structure built perpendicular to the shore to trap
littoral material or retard erosion of the shore.
high steep-faced promontory extending into the sea.
HIgH TIDE (HIGH ~A'£~). Maximum elevation reached by each rising tide.
HI~.Ku HIGH VAT~. The higher of the two high waters of any tidal day.
HINDC~STING, ~AFE. The use of historic synoptic wind charts to calculate char-
acteristics of waves that occurred at some past time.
UU~CA_-NE. An intense tropical cyclone in which winds tend to spiral inward
toward a core of low pressure. Maximum surface wind velocities equal or
exceed 75 miles per hour for several minutes or longer at some point.
Am,-~T. A short narrow waterway connecting a bay, lagoon, or similar body of
water with a large parent body of water.
J-~'~-~'X. On open seacoasts, a structure extending into a body of water that is
designed to prevent shoaling of a channel by.littoral materials.
shallow body of water usually connected to the sea.
LITTORAL. Of or pertaining to a shore, especially of the sea.
LITTOnaT. H%-£~wJ3~L (DRIFT). The sedimentary material moved in the littoral zone
under the influence of waves and currents.
LIT~OP~LTHANSPORT. The movement of littoral drift in the littoral zone by
waves and currents.
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I,ITTO~AT. THANSPORT RATE. Rate of transport of sedimentary material either
parallel or perpendicular to the shore.
LONGSHOHE CUIIHENT. A current moving essentially parallel to the shore, usually
generated by waves breaking at an angle to the shoreline.
LOg TIDE (LOg WATRa). Minimum elevation reached by each falling tide.
LOw~ LOg WA'fKa. The lower of the two low waters of any tidal day.
~ SEA 1.~-v~L. The average height of the surface of the sea for all stages of
the tide over a 19-year period.
~,~-AN (HIC~l~HIGB, HIGH, LOg, LOw, LOW) WAT~,~. Average height of the (higher
high, high, low, lower low) waters over a 19-year period.
MOP~KII~E. A ridge, mound, or irregular mass of boulders, gravel, sand, and
clay, carried in or on a glacier. A deposit of such a material left on
the ground by a glacier.
I~-2~RSHOP~E ZONE. An indefinite zone extending seaward from the shoreline well
beyond the breaker zone.
NECK. A narrow strip of land connecting a peninsula with the mainland.
OPTSHOP~E. The comparatively flat zone of variable width, extending from the
breaker zone to the seaward edge of the Continental Shelf.
OFFSHORE/ONSHOP~E ~. A current directed offshore/onshore of the shore.
POCKET BRACH. A beach, usually small, located between two littoral barriers.
~vmT141~T. A facing of stone, concrete, etc., built to protect erosion by wave
action or currents.
Sma~. Waves caused by wind at the place and time of observation.
SEAWa?J.. A structure separating land and water areas, typically designed to
prevent erosion or other damage due to wave action.
SI~4TDAo*tNALTIDE. A tide with two high and two low waters in a tidal day.
S~aTJ~W WA'f~-~. Water of such depth that surface waves are noticeably affected
by bottom topography.
SHOAL. (N) A detached elevation of sea bottom, composed of any material except
rock or coral, that may endanger surface navigation. (V) To become shal-
low gradually or to proceed from a greater to a lesser depth of water.
SHOR~. The narrow strip of land in immediate contact with the sea.
SHO~FACE (INSHORE ZONE). The narrow zone seaward from the low tide SHORELI)EE,
covered by water, over which the Beach sands and gravels actively oscil-
late with changing wave conditions.
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SHOP,~[NE. The intersection of a specified plane of water with the shore or
beach (typically taken as mean high water or mean higher high water).
SOIL CTA~SIFICATION. An arbitrary division of a continuous scale of grain
sizes.
SPIT. A small point of land or a narrow shoal projecting into a body of water
from the shore.
STO~ S~CE. A rise above normal water level on the open coast due to the ac-
tion of wind stress on the water surface or atmospheric pressure differen-
tials associated with storm events.
ZONE. The area of breaking waves.
Wind-generated waves that have traveled out of their generating area.
TIDAL DAY. The time of the rotation of the earth with respect to the moon, or
the interval between two successive upper transits of the moon over the
meridian of a place, approximately 24.84 solar days.
TIDAL RANGE. The difference in height between consecutive high and low waters.
TIDE. The periodic rising and falling of the water that results from the gra-
vitational attraction of the moon and sun and other astronomical bodies
acting on the rotating earth.
TONEOLO. A bar or spit that connects an island to the mainland or to another
island.
TOPO(~IAI~{Y. The configuration of a surface, including its relief and the posi-
tions of its streams, roads, buildings, etc.
~OPI~ STD~[~. A tropical cyclone with maximum winds less than 75 miles per
hour.
~D~F£. The direction opposite that of the predominant movement of littoral
materials.
~A~ CLImATe. The combination of waves of different heights, periods, and
directions.
~A~E ~EST. The highest point on a wave.
~A~ DI]I~TION. The direction from which a wave approaches.
~A~ ~I~. The vertical distance between a crest and the preceding trough.
~A~ ?~GT~. The horizontal distance between similar points on two successive
waves measured perpendicular to the wave crests.
PE~_IOD. The time for a wave crest to traverse a distance equal to one
wave length.
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WAVE PROPAGATION. The transmission of waves through water.
WAVE P~FRACTION. The process by which the direction of a wave moving in shal-
low water is altered as the part of the wave advancing in shallower water
moves more slowly, causiDg the wave crest to bend toward the shallower
water.
WAVE T~%TN. A series of waves from the same direction.
Waves being formed and built up by the wind.
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Policy 5
5.1
5.2
5.3
5.4
5.5
5.6
5.7
5.8
APPENDIX A: LONG ISLAND SOUND EROSION HANAGEHENT POLICIES
LONG ISLAND SOUND COASTAL HANAGEHENT PLAN
Minimize loss of life, structures, and natural resources from flood-
inE and erosion.
Comply with the Coastal Erosion Hazard Area statutes and re~mlations in
identified erosion hazard areas.
Goiply with Floodplain Hanagement statutes and re&mlations im identified
flood hazard areas.
Minimize losses of h-m-- life and structures from flooding and erosion
hazards by using the follovtn~ management neasures which are presented in
order of priority:
Protect and restore natural protective features.
Protect public lands and public trust lands and nae of these lands when
undertaking all erosion or flood control projects.
Site water-dependent uses and m~e navigation ~rastruc~ure to limit
adverse impacts on coastal processes.
Expend public funds for management or control of floodtn~ or erosionhaz-
ards only in areas of the coast which will result in proportionate public
benefit.
l.tmit potential loss of life and structural ~m~se in all development in
the coastal area.
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Policy 5 Hinimize loss of life, stzcuctu=es, and na~ncal resources from flood-
~ and eros[on.
Within the Long Island Sound coastal area, there are presently more than
8,200 buildings and other structures located in special flood hazard areas, and
over 1,200 buildings and other structures seaward of the present coastal ero-
sion hazard area boundary. In response to existing or perceived erosion and
flood hazards, many landowners have constructed erosion control structures.
Approximately 50 percent of the Sound shoreline has been armored with erosion
control structures, and the trend is continuing. In Suffolk County, for exam-
ple, only 8.96 miles cf 132.5 miles of the Sound shoreline was engineered with
riprap, bulkheads, or seawalls in 1969. Today, 43.7 miles of the county's
shoreline are hardened. This significant increase in the miles cf hardened
shoreline is not associated with water-dependent uses in Maritime Centers, but
rather for uses that do not have a functional relationship to coastal waters.
There are many erosion control structures located within the Long Island Sound
coastal area that are not necessary for erosion protection.
Erosion control structures often contribute to erosion both on and off the
site due to poor design and siting and lack of downdr£ft remediation. In-
creased erosion, aesthetic impairments, loss of public recreational resources,
loss of habitats, and water quality degradation can result from individual
hardening cf the shoreline. The cumulative impact of these structures is
potentially large. Before a permit is granted to allow construction of hard
erosion control structures, the purpose, function, impact, and alternatives to
the project need to be carefully evaluated to determine that the structures are
necessary and to avoid adverse impacts.
Although the Long Island Sound shoreline has been heavily fortified, there
are significant stretches of the coast that remain in a natural state. The
natural shoreline has an inherent natural, social, and economic value that
should be respected to ensure continuing benefits to the state and the region.
Consequently, those portions of the Sound shoreline that are not fortified
should generally remain in a natural conditlon to respond to coastal processes.
Where feasible and appropriate, portions of the shoreline that have been hard-
ened should be returned to a natural condition.
Development and redevelopment in hazard areas need to be managed to reduce
exposure to coastal hazards. Hardening of the shoreline is to be avoided,
except when alternative means, such as soft engineering alternatives, beach
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nourishment, revegetation, offshore bar building, or inlet sand bypassing, are
impractical to protect principal structures or extensive public investment
(land, infrastructure, facilities). Areas of extensive public investment in-
clude City Island and the Throgs Neck in the Bronx, the Cross Island Parkway
section of Queens, Bayville, the Asharoken tombolo, Sunken Meadow State Park,
portions of the identified Areas for Concentrated Development, and the ten
Maritime Centers.
Barrier landforms that protect significant public investment or natural
resources should be maintained. Soft structural protection methods are to be
used to conform with the natural coastal processes. Barrier beach landforms
should be maintained by using clean compatible dredge material when feasible,
for beach nourishment, offshore bar building, or marsh creation projects.
In suitable locations and where appropriate, interpretative materials
could be considered to enhance the public's understanding of natural coastal
processes.
This policy seeks to protect life, structures, and natural resources from
flooding and erosion hazards throughout the Long Island Sound coastal area.
The policy reflects state flooding and erosion regulations, and provides mea-
sures for reduction of hazards and protection of resources.
Policy standards are divided into eight sections. The first two sections
reflect state flooding and erosion regulations. Section 3 presents standards
directed at protection of life and property, including measures for minimizing
losses from flooding and erosion arranged in order of priority, ranging from
avoidance to hard structural approaches. Section 4 addresses natural protec-
tive features. Section 5 addresses protection of public funds or public trust
lands. Measures for water-dependent uses and navigation are provided in sec-
tion 6. Section 7 establishes conditions for expenditure of public funds for
management of flood and erosion hazards contingent on public benefit. Section
8 addresses reduction of hazards through emergency planning and building con-
struction standards.
Policy Standards
5.1 Comply with the Coastal Erosion Hazard Area statutes and regulations in
ident~4:ied erosion hazard areas.
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5.2 Comply with Floodplain Hanagement statutes and regulations in identified
flood hazard areas.
5.3
llintmize losses of b,m-u life and structures from floodinS and erosion
hazards by using the following management measures which are presented in
order of priority:
Coastal Barrier Resource Area is any one of the designated and mapped areas
under the Coastal Barrier Resources Act of 1982, (P.L. 97-348), and any areas
designated and mapped under the Coastal Barrier Improvement Act of 1990 (P.L.
101-591), as administered by the U.S. Fish and Wildlife Service, and any future
designations that may occur throuEh amendments to these laws.
Coastal Erosion Hazard Area is any coastal area included within the Erosion
Hazard Area as designated by the State Department of Environmental Conservation
pursuant to the Coastal Erosion Hazard Areas Act of 1981 (Article 34 of the
Environmental Conservation Law), and any coastal area included within a V-zone
as designated on Flood Insurance Rate Maps prepared by the Federal EmerEency
ManaEement AEency pursuant to the National Flood Insurance Act of 1968 (P.A.
90-4~8) and the Flood Disaster Pro¢ection Act of 1973 (P.L. 93-234).
Natural protective features are beaches, dunes, shoals, bars, spits, barrier
islands, bluffs and wetlands; and associated natural veEetation.
Minimize potential loss and damage by locating development and structures
away from flooding and erosion hazards.
1. Avoid developing new structures and uses or reconstruction of struc-
tures damaged by 50% or more of their value in areas which are likely
to be exposed to hazards unless:
a. the structure or use functionally requires a location on the
coast or in coastal waters, or
b. the new development would be located in an area of substantial
public investment, or
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c. the new structure or use is necessary for shoreline development
which:
(1) reinforces the role of Maritime Centers in concentrating
water-dependent uses, and
(2) would not result in impairment of natural resources
2. Locate new structure which are not functionally dependent on a loca-
tion on or in coastal waters, are not in areas of substantial public
investment, or do not reinforce the role of a Maritime Center, as far
away from flooding and erosion hazards as possible.
a. No development is permitted in natural protective feature areas,
except for artificial beach nourishment and coastal structures
including docks, piers, wharves, groins, jetties, seawalls,
bulkheads, breakwaters, and revetments.
b. Locate new development away from coastal hazards associated with
inlet areas.
c. Avoid hazards by siting structures to maximize the distance from
Coastal Erosion Hazard Areas.
d. Provide sufficient lot depth to allow relocation of structures
and maintenance of required setbacks over a period of thirty
years.
3. Where practical, moving existing structures and development which are
exposed to hazards away from the hazards is preferred over maintain-
ing structures and development in place. Maintaining existing devel-
opment and structures in hazard areas may be warranted for:
a. structures which functionally require a location on the coast or
in coastal waters, or
water-dependent uses which, by the nature of the use, cannot
avoid exposure to hazards, or
c. sites in areas with extensive public investment, public infra-
structure, or major public facilities, or
d. sites where relocation or an existing structure is not practical
4. Provide public infrastructure in or near identified high velocity
flood zones, structural hazards areas or natural protective features
only if the infrastructure:
a. will not promote new development or expansion of existing devel-
opment in a Coastal Barrier Resource Area or a Coastal Erosion
Hazard Area
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b. is designed in a manner which will not impair protective capaci-
ties of natural protective features, and
c. is designed to avoid or withstand damage from flooding and
erosion.
Use vegetative non-structural measures which have a reasonable probability
of managing flooding and erosion based on shoreline characteristics in-
cluding exposure, geometry, and sediment composition. Use vegetative
measures to increase protective capacities of natural protective features
at every opportunity.
Enhance existing natural protective features and use non-structural mea-
sures which have a reasonable probability of managing erosion.
1. Enhance the protective capabilities of beaches by using fill, artifi-
cial nourishment, dredge disposal, or by restoring coastal processes
according to the following standards:
a. Use only clean sand or gravel with a grain size equivalent to or
slightly larger than the native material at the project site.
b. Design criteria for enhancing the protective capabilities of
beaches should not exceed the level necessary to achieve protec-
tion from a 30 year storm, except where there is an overriding
public benefit.
c. Provide for sand by-passing at engineered inlets or other shore
protection structures to maintain coastal processes and protec-
tive capabilities of beaches.
2. Protect and enhance existing dunes or create new dunes using fill,
artificial nourishment, or entrapment of windborne sand.
a. Use only clean sand with a grain size equivalent or slightly
larger than native dune material
b. Design criteria for created dunes should not exceed the overtop-
ping height defined by the 30 year storm, except where there is
an overriding public benefit.
c. Enhance existing or created dunes using snow fencing and dune
vegetation.
d. Construct and provide for use of walkovers to prevent pedestrian
damage to existing and enhanced dunes.
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5.4
A.
Increase protective capacity of natural protective features using
practical vegetative measures in association with all other enhance-
ment efforts.
Use hard structured erosion protection measures for control of erosion
only where:
1. Avoidance of the hazard is not practicable because a structure is:
functionally dependent on a location on or in coastal waters; located
in an area of extensive public investment; or reinforces the role of
Maritime Centers.
2. Vegetative approaches to controlling erosion are not effective.
3. Enhancement of natural protective features would not prove practical
in providing erosion protection.
4. Construction of a hard structure is the only practical design consid-
eration and is essential to protecting the principal use.
5. The proposed hard structural erosion protection measures:
a. are limited to the minimum scale necessary
b. are based on sound engineering practices
6. Practical vegetative methods have been included in the project design
and implementation.
7. Adequate mitigation is provided and maintained to ensure that there
is no adverse impact to adjacent property, to natural coastal pro-
cesses and natural resources, and, if undertaken by a private proper-
ty owner, does not incur significant direct or indirect public costs.
P~otect and zesto;e natural p;otective features.
Maximize the protective capabilities of natural protective features by:
1. avoiding alteration or interference with shorelines in a natural
condition
2. enhancing existing natural protective features
3. restoring the condition of impaired natural features wherever
practical
4. using practical vegetative approaches to stabilize natural shoreline
features
5. managing activities to limit damage to, or reverse damage which has
diminished, the protective capacities of the natural shoreline
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5.5
A.
B.
C.
providing relevant signage or other educational or interpretative
material to increase public awareness of the importance of natural
protective features
Minimize interference with natural coastal processes.
1. Provide for natural supply and movement of unconsolidated materials
and for water and wind transport.
2. Limit intrusion of structures into coastal water.
3. Limited interference with coastal processes may be allowed where the
principal purpose of the structure is necessary to:
simulate natural processes where existing structures have al-
tered the coast, or
b. provide necessary public benefits for flooding and erosion pro-
tection, or
c. provide for the efficient operation of water-dependent uses, and
provided that
d. mitigation is provided and maintained to ensure that there is no
adverse impact to adjacent property, to natural coastal pro-
cesses and natural resources, and, if undertaken by a private
property owner, does not incur significant direct or indirect
public costs
Protect lmblic lands and public trust lands and use of these lands when
undertaking all erosion or flood control projects.
Retain ownership of public trust lands which have become upland areas due
to fill or accretion resulting from erosion control projects.
Avoid losses or likely losses of public trust lands or use of these lands,
including public access along the shore, which can be reasonably attrib-
uted to or anticipated to result from erosion protection structures.
Provide and maintain compensatory mitigation of unavoidable impacts to
ensure that there is no adverse impact to adjacent property, to natural
coastal processes and natural resources or, to public trust lands and
their use.
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5.6 Site rater-dependent uses and manage navisation ~nfrastruct~te to l~nit
adverse ~mpacts on coastal processes.
Except in Maritime Centers, site new water-dependent uses in erosion haz-
ard areas only if the use could not practicably be located outside the
hazard area.
Manage navigation channels to limit adverse impacts on coastal processes:
1. Design channel construction and maintenance to protect and enhance
natural protective features and prevent destabilization of adjacent
areas by:
a. using dredging setbacks and slopes from established channel
edges
b. locating channels away from erodible features, where feasible
c. preventing adverse alteration of basin hydrology
d. including by-passing methods to maintain navigability and reduce
frequency of dredging
2. Use clean dredged material as beach nourishment whenever the grain
size of the dredged material is the same size or slightly larger than
the grain size of the potential recipient beach.
Manage stabilized inlets to limit adverse impacts on coastal processes
1. Include sand bypassing at all engineered or stabilized inlets which
interrupt littoral processes.
2. Manage flood and ebb tidal deltas to simulate natural processes.
3. Avoid extending Jetties when it will increase disruption of coastal
processes.
5.7
Expend public funds for management or control of floodtnE or erosion haz-
ards only in areas of the coast vhtch viii result in proportionate public
benefit.
Give priority in expenditure of public funds to actions which protect public
health and safety, mitigate past flooding and erosion problems, protect areas
of intensive development, and protect substantial public investment (land,
infrastructure, facilities).
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Expenditure of public funds for flooding or erosion control projects;
1. is limited to those circumstances where public benefits clearly ex-
ceed public costs
2. is prohibited for the exclusive purpose of flooding or erosion pro-
tection for private development, and
3. may be apportioned among each level of participating governmental
authority according to the relative public benefit accrued.
Factors to be used in determining public benefit attributable to the pro-
posed flood or erosion control measure include:
1. economic benefits derived from protection of public infrastructure
and investment and protection of water-dependent commerce, or
2. protection of significant natural resources and maintenance or resto-
ration or coastal processes, or
3. integrity of natural protective features, or
4. extent of public investment, or
5. extent of existing or potential use
Application of these factors indicate that public expenditure for erosion and
flood control projects may be warranted in: City Island and the ThroEs Neck in
the Bronx, the Cross Island Parkway section of Queens, Bayville, the Asharoken
tombolo, Sunken Meadow State Park, Wildwood State Park, portions of the identi-
fied Areas for Concentrated Development, and the Maritime Center of Port
Chester, Mamaroneck Harbor, New Rochelle-Echo Bay, City Island, Port
Washington-Manorhaven, Glen Cove, HuntinEton Harbor, Northport Harbor, Port
Jefferson, and Mattituck Inlet.
5.8 Limit potential loss of life amd st~t~xal ~m~e im all de~l~pment in
the coastal area.
Comply with the provisions of any municipal erosion management plan, con-
sistent with the provisions of this policy.
Construct buildings to meet applicable FEMA and New York State Uniform
Building and Fire Protection Code standards.
1. Minimize additional hazards caused by storm-driven debris resulting
from damage to buildings and other structures:
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a. locate structures away from hazard areas to limit generation of
water-borne debris
b. limit the amount of break-away structures including decks, walk-
ways and walls below the 100 year flood level
2. Limit the public cost of repair and cleanup resulting from damages to
moveable structures within structural hazard areas:
a. ensure that property owners recover debris resulting from damage
to movable structures in structural hazard areas
b. remove debris from public lands and waters within 60 days of
damaging events
3. Include sea level rise calculations in siting and design of all major
projects having more than a thirty year design life
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