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OCR for page 44
3
Management and Approaches
INT1lODUCTION
Any attempt to formulate national policies to address coastal ero-
sion hazards confronts a task of substantial complexity. This chapter
reviews some of the elements that contribute to this complexity:
.
political);
types of diversity (e.g., physical, settlement morphology, and
types of private and public participants in coastal manage-
ment,
. methods available for erosion hazard reduction (engineered
projects) and building and land use management; and
~ institutional variation of federal approaches to coastal man-
agement.
TYPES OF DIVERSITY
Federal resource management programs inevitably confront the
dilerru~na of how to reconcile the need for uniform national policy
objectives with regional diversity of geographic conditions. This issue
arises, for instance, with respect to air and water quality standards,
ocean dumping and disposal of dredged spoils, wetland regulations,
and floodplain management. The nation's coastlines are diverse in
44
OCR for page 45
MANAGEMENT AND APPROACHES
45
several respects: physical, settlement, and political. Each of these
classes of diversity is reviewed briefly below.
Physical Diversity
Coastal shorelines differ markedly in physical characteristics and
in vulnerability to erosion, as discussed in Chapter 2. Principal types
of shorelines and examples of their locations include:
crystalline bedrock (e.g., central and northern Maine);
eroding bluff (e.g., outer Cape Cod, Great Lakes);
pocket beach (e.g., southern New England, California, Ore-
gon);
strandplain beach (e.g., Myrtle Beach, South Carolina, and
Holly Beach, Louisiana);
barrier beach (e.g., New York and Texas);
coral reef and mangrove (e.g., South Florida); and
coastal wetland (e.g., Louisiana).
Erosion hazards can affect each of the above except for bedrock
shorelines. Erosion, as compared to accretion or stability, and its
rate over time at a given point along the shoreline depend on factors
such as (1) direction of littoral drift, (2) inlet dynamics, (3) sand
supply, (4) short- and long-term climate fluctuations, (5) gradient of
submerged ocean or lake bottom, (6) relative mean sea level, and (7)
human actions affecting shoreline processes (see Table 2-1~.
Settlement Diversity
Shorelines differ dramatically in their human settlement char-
acteristics. Extensive areas of the nation's coastlines essentially are
undisturbed, and much of the shore remains in a relatively undis-
turbed condition (e.g., national seashores, national forests, parks,
wildlife refuges, military bases and recreation areas, state and local
parks, and nature preserves owned by the Nature Conservancy and
comparable organizations). Shorelines within such facilities gener-
ally are uninhabited except for private inholdings, which are com-
mon in several of the major national seashores (e.g., Cape Cod,
Massachusetts; Fire Island, New York; Assateague Island, Virginia
and Maryland; and Cape Hatteras, North Carolina) and national
lakeshores (Indiana Dunes and Sleeping Bear Dunes). Substantial
areas of shoreline remain in private hands but undisturbed because
OCR for page 46
46
MANAGING COASTAL EROSION
of lack of access, distance to population centers, physical unsuitabil-
ity for development, or personal preference of the owner.
At the other extreme, shorelines may be developed extensively
with port facilities or lined with commercial, industrial, or high-
density residential and resort buildings. Such urbanized shorelines
often are hardened by protective riprap, seawalis, or other engineered
structures, which may substantially reduce or eliminate the threat of
erosion to the protected area.
Efforts to protect certain segments of shoreline, however, can in
some circumstances induce increased erosion on nearby unprotected
shorelines. For instance, groins or jetties can deprive downdrift areas
of natural sand supply. On the other hand, groin fields filled by beach
nourishment have been successful.
Between the two extremes of undeveloped and highly urban-
ized shorelines, coastal settlement types vary widely. In the past,
settlements on the shorelines were categorized into four types: (1)
village, (2) urban, (3) summer, and (4) empty places (Burton et
al., 1968~. Today, these classifications are blurred as former summer
colonies become winterized for year-round use, high-rise condomini-
ums replace the "village" atmosphere of former small communities
like Ocean City, Maryland, and major development corporations re-
shape the coastal landscape an at Hilton Head, South Carolina, or
Amelia Island, Florida (Platt et al., 1987~.
During the 1970s and 1980s, many former low-density resort
communities experienced rapid structural and demographic growth.
This growth was accompanied by the development of infrastructure
in the form of sewer lines, water lines, access routes, and beach
protection and nourishment projects, largely subsidized by the federal
government. Furthermore, the availability of federal flood insurance
has been identified as at least a marginal incentive to further coastal
development (U.S. General Accounting Office, 19823.
Political Diversity
The nation's shorelines also show a diversity in the nature and
form of political jurisdictions. Nonfederal units of public and quasi-
public authority operating in coastal areas include private home-
owners' associations, incorporated municipalities, special districts,
counties, and states. Of course, all U.S. shorelines are subject to
state jurisdiction, but the nature of that role differs considerably
from one state to another. Furthermore, most regions of the nation
OCR for page 47
MANAGEMENT AND APPROACHES
47
differ In terms of substate political authority. The coast of New Eng-
land, for instance, is occupied entirely by incorporated towns and
cities. The unknot civil divisions of New York State include incor-
porated villages, towns, cities, and counties. New Jersey has all of
those as well as boroughs. Local government functions in Maryland
and Virginia are largely provided at the county level, except for self-
governing cities such as Baltunore and Virginia Beach. Elsewhere,
privately owned shorelines may be subject to municipal or county
jurisdiction, depending on whether or not the location in question is
within an incorporated municipal unit. Furthermore, in the case of
coastal barriers, local political units may be self-governing (i.e., lim-
ited to the barrier itself) or appendant (i.e., part of a larger mainland
jurisdiction).
The efficacy of coastal management is related in part to the
political geography of minor civil divisions of particular shorelines.
Many local units tend to ignore external effects on their neighbors in
their choice of approach to the management of coastal erosion (Platt
et al., 1987~.
These three kinds of diversity—physical, settlement, and politi-
cal serve to complicate the shaping of national policy on coastal
erosion management. They suggest that no single approach is am
propriate or inappropriate everywhere. Public planners and decision
makers should avoid basing policies on stereotypes or preconcep-
tions as to "typical" shorelines and their state of development and
governance.
There is precedent for the administration of a national policy
that is geographically selective. For example, the Coastal Barrier
Resources Act (CBRA) of 1982 (discussed later In this chapter)
prohibits further federal flood insurance coverage and other federal
incentives to development for undeveloped and unprotected coastal
barriers. This act is selective In its coverage, according to the physical
character of the shoreline (coastal barrier), settlement type (undevel-
oped), and legal status (nonpublic and protected). The CBRA thus
is one way to conduct selective implementation of federal policies
designed to mitigate future losses caused by coastal erosion.
PRIVATE AND PUBLIC PARTICIPANTS IN
COASTAL MANAGEMENT
The use of coastal land involves diverse private and public de-
cision makers and other participants. The exact mix of parties and
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48
MANAGING COASTAL EROSION
their respective roles and influence over the development of coastal
property vary from one location to another. The types of diver-
sity discussed in the preceding section physical, settlement, and
political are major factors in determining the interested parties
for any given location and development situation. Management of
coastal erosion and flood hazards must recognize the variation in the
interests and the varied roles of relevant parties.
Priorate Sector
Among private sector parties
ment and use are
.
i:
coastal property owners,
developers and builders,
evolved in coastal land develop-
o homeowner associations,
. neighbors or other residents affected by the use of a particular
site,
lenders, and
. realtors.
Private property owners are vested with substantial but not
exclusive authority to determine the use of their land. Riparian
rights traditionally entitle the waterfront land owner to embark upon
the water; but the state, sometimes in conflict with those rights, is
custodian of a public trust to control the use of the water and the
land under it for the benefit of all. Property owners are typically
the initiators of land use change (e.g., from an open to a developed
condition or from one development form to another). Private owners
are constrained in the exercise of this prerogative in several respects:
.
Nuisance laws protect neighboring property owners and the
public at large from harm caused by unreasonable use of private
property, as considered in the case of Lummis v. Lily, 429 N.E.2d
1146, 1982. This case involved a stone groin on Cape Cod, Mas-
sachusetts, and lists the factors to be applied in determining if the
structure was "reasonable" and therefore immune from a damage
claim by a neighbor.
_ . ~ ~ ~ . . ..
Covenants and deed restrictions can arise through private
terms of a subdivision instrument of conditions, through retention
of certain rights by a prior seller that "run with the land" or by
other means. Such private restrictions, when legal in purpose and
OCR for page 49
MANAGEMENT AND APPROACHES
49
recorded properly, are enforceable against private owners whose land
is thereby encumbered. These restrictions include
municipal/county zoning and subdivision regulations;
state building codes, wetland and floodplain regulations,
and coastal zone management regulations; and
~ federal environmental regulations.
Developers/builders may or may not hold an ownership interest
in the site in question. They may operate in partnership with the
owner and/or with other investors. Professional developers/builders
are held to a higher level of responsibility with respect to the
quality and safety of the resulting structure than nonprofessional
owners. The possibility of professional liability affecting the devel-
oper/builder and professional advisors (e.g., architects, engineers,
and lawyers) may be a constraint on unwise construction in erosion-
prone locations.
Homeowner associations are private nonprofit corporations es-
tablished by a developer to own and manage the common facilities
of a particular residential subdivision. An association also can serve
as "watchdog" to enforce subdivision deed restrictions. The mem-
bership of the association consists of the owners of all lots in the
subdivision. In coastal areas homeowner associations may own and
manage beach and shoreline property on behalf of the subdivision lot
owners.
Neighbors and other residents have a voice in the local zoning
process through mandatory public notice and hearing provisions of
state law.
Lenders include banks, savings and loan associations, pension
funds, insurance companies, and other institutions that finance land
development. Lenders that are "federally related" (e.g., insured or
regulated by federal agencies) are required to ascertain and inform
borrowers as to whether a site is located within a "special flood
hazard area" identified by the National Flood Insurance Program
(NF1P). If so, the borrower is required to purchase flood insurance
for the acquisition or improvement of structures on such a site (42
USC Section 4104a). This requirement could be extended to erosion-
prone areas not now included in flood hazard zones.
Realtors have a professional duty to disclose flood or erosion
hazards known to them or ascertainable from published maps of the
NF1P. Like developers, realtors can be held liable to a buyer for
concealing or failing to ascertain the existence of such hazards.
OCR for page 50
so
MANAGING COASTAL EROSION
Public Sector
Public participants in coastal land development and management
include
.
incorporated municipalities (e.g., villages, boroughs, towns,
cities);
counties;
special districts;
states; and the
federal government.
The roles performed by various tiers and units of government
differ from one state and location to another, as discussed in the
preceding section. Briefly, the principal roles of public entities that
relate to development in erosion-prone coastal areas are the following:
land ownership (e.g., national, state, local parks);
police power (e.g., zoning, subdivision, environmental, and
hazard mitigation regulations);
. infrastructure funding and/or operation (e.g., roads, bridges,
causeways, sewer and water lines); and
~ development (e.g., convention centers, cultural facilities,
sports complexes).
Not all of these roles pertain to each tier of public authority.
The following matrix suggests, in general terms, the functions of
respective types of governmental units, although these vary among
states and localities (Table 3-1~. This matrix suggests that the role
common to all levels of government is the funding and/or opera-
tion of the physical infrastructure. This function typically requires
multilevel participation In the form of funding, design, licensing,
operation, and inspection of facilities.
A national program for coastal erosion management must ad-
dress the siting and design of public infrastructure that encourages
development in erosion hazard areas. (Eroding shores within desig-
nated units of the Coastal Barrier Resource System already are off
limits to federal infrastructure funding and flood insurance under the
CBRA of 1982.)
In summary, the development and management of land subject
to coastal erosion are influenced by the actions of diverse private
and public participants. A national policy on coastal erosion must
acknowledge this complexity and seek to achieve erosion/flood loss
reduction through multiple approaches involving different classes of
OCR for page 51
MANAGEMENT AND APPROACHES
TABLE 3-1 Functions of Governmental Units
51
Infrastructure
Coastal Police Provider/ Land Use
Landowner Power Funding Developer Planning
Municipality x x x x x
Special district o x x
County o x* x* x o
S rate x x x x
Federal x x x o
NOTE: x, major role in most states; o, minor role in most states; and - , not a role
in most states.
Primarily for unincorporated areas.
participants and actions (e.g., local planning and zoning, public land
acquisition, withholding of infrastructure funding, and clarification
of professional duties of lenders, developers, and realtors). All ap-
proaches require improved public understanding of the nature and
implications of coastal erosion.
RELEVANT FEDERAL PROGRAMS
Since the 1930s, Congress has created a variety of programs
and initiatives relating to management of coastal areas, including
the Great Lakes. These have pursued a number of objectives, some
of them in conflict with others (e.g., navigation, national defense,
public recreation, riparian rights, public trust for underwater lands,
protection of fish and wildlife resources, economic development, miti-
gation of pollution, and reduction of losses owing to natural hazards,
including coastal erosion). Federal constitutional powers involved
in these efforts have included spending power, taxation power, in-
terstate commerce power, and regulatory police power. Approaches
taken have varied widely from one program to another. Those of
primary importance to this discussion are the following:
1. U.S. Army Corps of Engineers: coastal protection works,
navigation improvements, and regulation of dredge and fill.
2. U.S. Department of the Interior: acquisition of national parks
and national wildlife refuges.
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52
MANAGING COASTAL EROSION
3. U.S. Environmental Protection Agency: regulation of ocean
dumping, discharges into waters of the United States, research on
sea level rise, etc.
4. National Oceanic and Atmospheric Administration/Office of
Ocean and Coastal Resource Management: funding and technical
assistance to support state coastal zone management programs.
5. Federal Emergency Management Agency/Federal Insurance
Administration: mapping of coastal hazard areas and administration
of the NF1P.
6. Coastal Barriers Resources Act of 1982.
The following sections briefly review these programs, followed by
a more detailed discussion of the coastal aspects of the NF1P.
U.S. Arnold Corps of Engineers
The Army Corps of Engineers (COE) has been engaged in nav-
igation improvements of the nation's waterways, both intracoastal
and inland, since 1824. The Intracoastal Waterway extending from
Texas to New Jersey began prior to World War IT and has con-
tributed to the public enjoyment and economic development along
the Atiantic and Gulf coastlines. COE river and harbor projects,
such as channel dredging and inlet stabilization, have similarly pro-
moted economic and recreational usage of estuarine areas, bays, and
harbors along the nation's ocean and Great Lakes shorelines.
COE coastal erosion activities have included the construction of
seawalIs, jetties, and groin fields and beach restoration and nour-
ishment projects. These projects have been approved by Congress
with varying cost-sharing ratios. The nonfederal percentage of to-
tal project costs varies depending on local interest; however, many
project costs are shared on a 50/50 basis. Since 1970 the National En-
vironmental Policy Act has required that an Environmental Impact
Statement be prepared for COE coastal protection and navigation
projects, which are deemed to be "major federal actions significantly
affecting the human environment."
In addition to its civil works functions, the COE administers
several permit programs regulating the discharge of material into
navigable waters and all construction therein. Of particular rele-
vance to the management of coastal areas subject to erosion and sea
level rise, COE administers (except in Michigan where the state has
assumed 404 administrative authority) the "dredge and fill" permit
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MANAG~ENT AND APPROACHES
53
program under Section 404 of the Federal Clean Water Act. Pur-
suant to guidelines established by the U.S. Environmental Protection
Agency (EPA), COE must approve any proposed construction includ-
ing dredge or fill in "waters of the United States," including wetlands
bordering navigable waters (Platt, 19873. In cooperation with EPA,
COE thus plays a critical role in relicensing of large- or small-scare
development in coastal and estuarine wetlands. This encompasses
much of the ongoing development in areas subject to coastal floods
and erosion.
U.S. Department of the Interior
The National Park Service (NPS) and the Fish and Wildlife
Service (FWS) of the Department of the Interior (DON) own and
manage substantial land holdings along the nation's eroding coast-
lines. Each agency controls extensive areas of open coast shorelines,
coastal barriers, estuarine wetlands, zones of fish migration, and
eroding shorelines on the Great Lakes.
Most NPS areas subject to coastal erosion are located within the
nation's 10 national seashores and four national lakeshores. These
were established during the 1960s and 1970s, beginning with the
authorization of the Cape Cod National Seashore in 1961 (Cape
Hatteras was designated a national park in 1937~. Coastal erosion
has adversely affected many of these facilities, notably Cape Cod,
where a single winter storm in 1978 destroyed parking lots, access
roads, visitor facilities, and a national landmark, the "Outermost
House." The Cape Hatteras Lighthouse is another major national
historic landmark managed by the NPS that is threatened by coastal
erosion. An NRC study of options to preserve that lighthouse recom-
mended that it be moved landward rather than constructing shore
protection structures (National Research Council, 1988~. Another
NPS area threatened by severe coastal erosion is Indiana Dunes Na-
tional Lakeshore. Jetties built during the 1970s have interfered with
sediment transport and caused the loss of most of the area's once
impressive sand beach. (In 1989, some beach has reappeared with
lower lake levels.)
FWS administers the National Wildlife Refuge System, along
with several dozen units in coastal areas. In some cases, such as
Assateague Island (Maryland and Virginia), FWS manages a wildlife
refuge directly adjacent to an NPS facility. Wildlife refuges by def-
inition have few human-made artifacts to be threatened by coastal
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54
MANAGING COASTAL EROSION
erosion. Nevertheless, the gradual submergence of existing wetland
habitat ~ an important long-term issue for the FWS.
U.S. Environmental Protection Agency
The EPA promulgates guidelines for the adrn~nistration of the
Section 404 Dredge and Fid Program for coastal and inland wet-
lands. An important provision of these guidelines is that non-water-
dependent uses are disfavored in wetlands. The COE cannot issue
a Section 404 dredge and fill perrrut for such an activity if an am
propriate upland site is available. The burden of proof lies with the
applicant to demonstrate that such a site ~ not available.
To obtain parrots in Unprotected areas, the applicant must
provide Mitigation" of adverse impacts through appropriate design,
location, and, in some cases, restoration or creation of other wetlands.
Building techniques designed to mitigate harm to wetlands also may
be useful in averting threats to the same structures from storm surge
and shore erosion. EPA is also conducting a series of studies of major
embayments under the National Estuary Program.
National Oceanic and Atmospheric Administration
The Coastal Zone Management (CZM) Act of 1972 established a
joint federal-state process for coastal zone planning and management.
The federal CZM program is administered by the Office of Ocean and
CoastalResource Management (OCRM) of the National Oceanic and
Atmospheric Administration (NOAA). The act declared a national
policy favoring better management of coastal land and water re-
sources, cited the need for federal-state collaboration in planning
for nonfederal portions of the coastal zone, and authorized funds
to assist states in developing and administering their own coastal
management plans.
The federal CZM program does not set mandatory federal stan-
dards, nor does it require the issuing of fecleral licenses or permits by
OCRM. Instead, the program facilitates state and local coastal zone
planning through funding and technical assistance. To be eligible
for OCRM funding, a state plan must address a number of pub-
lic policy issues, such as navigation, habitat protection, economic
development, public recreation and access to shorelines, scientific
research, energy development, and natural hazard mitigation. As of
1989, 29 of the 35 eligible states and territories bordering oceans and
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60
MANAGING COASTAL EROSION
profile after construction of a seawall is similar to the preconstruction shape if
a sediment supply exits, showing the same number of bars with approximately
the same volumes and relative locations. The form of the erosional response
to storms at seawalls is typically different. Limited evidence indicates that the
subaqueous nearshore profile on a sediment-deficient coast with seawalls does
not steepen indefinitely, but approaches an equilibrium configuration compatible
with the coarser-grained particles comprising the bottom sediment.
As pointed out by Dean (1986), the only principle that is def-
initely established is the one of "sediment conservation." Coastal
armoring (e.g., a riprap or seawall) neither adds to nor removes sand
from the sediment system but may be responsible for the redistri-
bution of sand and can prevent sand from entering the system. Al-
though armoring can cause additional localized scour during storms,
both in front of and at the ends of the armoring, there are no fac-
tual data to support claims that armoring causes profile steepening,
increased longshore transport, transport of sand to a substantial
distance offshore, or delayed poststorm recovery.
Low-profile seawalIs or dikes can be used to retain a beach or
fillet of sand above the normal beach profile level. Such structures
are referred to as perched beaches and may exist as single-level or
terraced structures.
OFFSHORE BREAKWATERS
Offshore or detached breakwaters typically are constructed from
rock or concrete armor units and protect the shoreline by reducing
wave energy reaching it. They also promote sediment deposition
leeward of the structures. Most offshore breakwaters built for shore
protection are segmented and detached; thus, they provide substan-
tial protection to the shoreline without completely stopping Tong-
shore sand transport. They do not deflect and relocate currents, like
breakwaters that project from the land. Unlike seawalIs, revetments,
or bulkheads, breakwaters aid in the retention of the beach because
they reduce wave energy. A main disadvantage is that they are more
expensive to build than land-based structures.
Segmented, detached breakwaters have been used successfully
to protect shorelines from erosion in many countries such as Japan,
Spain, Italy, and Israel. The use of these structures in the United
States has been limited to a few sites in Massachusetts, Ohio, Penn-
sylvania, Virginia, and Hawaii. Submerged breakwaters, or artificial
reefs, have been used in many parts of the world, notably in Italy but
recently in Florida. They may be composed of sunken barges or ships
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MANAGEMENT AND APPROACHES
61
or any heavy objects that break up wave action. The costs can be
much less then for breakwaters that project above the water surface
because they do riot have to absorb the full wave impact, but merely
cause storm waves to break and spill their energy in turbulence.
SAND BYPASSING
Inlets, navigation channels, and harbor entrances all interrupt
the natural flow of sediment transport along the shoreline. The
interrupted flow of sand is diverted either offshore in ebb tide shoals,
into bays or lagoons in flood tide shoals, or in navigation channels.
They generally cause shoaling and downdrift migration of channels,
which require frequent dredging in order to maintain safe navigation.
As a result, erosion occurs downdrift of the interrupted coastline.
Sand bypassing, by either a fixed or floating pumping system, restores
the natural flow of sand to the downdrift shorelines and reduces the
need for channel dredging. Successful operations of this type exist
in many countries such as Australia, Japan, and South Africa. In
Florida the use of two fixed bypassing plants for a period of 30 years
suggests the feasibility of such systems to alleviate human-induced
erosion downdrift from inlet control structures. Floating dredge
(temporary) bypass operations also have been used in the United
States. One example is a federal project at Channel Islands Harbor,
California, where over 1 million cubic yards of sand is bypassed on a
biennial basis past two harbor entrances to restore eroding downdrift
beaches (Herron and Harris, 1966~.
DUNE BUILDING
Natural sand dunes are formed by winds blowing onshore over
the beach, transporting sand landward. Grass and sometimes bushes
grow on sand dunes, creating a natural barrier against sea attack.
The dunes provide a reservoir of beach sand during severe storms
and thus help prevent flood and wave damage to adjacent property.
In areas where substantial dunes exist, the poststorm beach width
can be greater than the prestorm width.
Attempts have been made to mimic nature by promoting the for-
mation of artificial dunes. Artificial dunes have been created in many
countries around the world, as well as in the United States. States
where large-scale dune construction has occurred include North Car-
olina, Texas, Florida, and New Jersey.
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62
MANAGING COASTAL EROSION
Building and [and Use Management
Since the advent of the NF1P in 1968, legal and institutional
~ "nonstructurally ~ measures have become unport ant mechanisms used
to reduce the vulnerability of coastal and riverine structures to flood
and erosion losses. Planners have often seen engineered responses to
coastal erosion as unsuitable from an economic and environmental
perspective, especially when used to protect privately owned, lower
density residential development. One prorn~sing approach to coastal
management Is to influence the location, elevation, and design of new
or substantially redeveloped structures through public building and
land use controls.
The NF1P in particular has fostered the adoption of floodplain
management standards by some 1200 coastal communities nationally,
containing an estimated 43 million people (Congressional Research
Service, 1987~. Like their counterparts along inland floodplains,
these communities must require minimum elevation of new structures
above estimated Midyear flood ("base flood") levels that include the
effect of wave heights. These land clevelopment restrictions generally
have been held to be constitutional (KusTer, 1982~.
SETBACK REQUIREMENTS
Coastal construction standards under the NF1P have emphasized
elevation rather than horizontal displacement. New buildings on
substantial pilings up to 20 feet above grade are a familiar site
in recently built communities along the AtIantic and Gulf coasts.
But horizontal displacement is required under the flood insurance
program's minimum standards, only to the extent that new buildings
in coastal high-hazard zones (V-zones) (see Figure 3-2) must be
"located landward of the reach of mean high tides and must not
alter dunes or mangrove stands (44 CFR Section 60.3(e)~. Even
these minimal requirements do not apply to coastal A zones (e.g.,
bayside or other non-open ocean shorelines). Where either V-zone
or A-zone coastal shores are experiencing erosion, further horizontal
displacement of new or rebuilt structures is needed.
A number of coastal states have established horizontal setbacks
for new construction at the individual state level (Hildreth, 1980;
Maloney and O'Donnell, 1978~. According to an unpublished NOAA
memorandum (Houlahan, 1988), there are three basic approaches
states have taken: (1) natural resource protection statutes, (2) fixed
setback lines, and (3) average annual recession rate setbacks. The
