Coastal construction practices

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

January 1982 MAP-23

COASTAL
CONST TION
TICES
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- - - - - - - - - -

Edited by
Christopher P. Jones
and
Leigh Taylor Johnson

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.F532 Cooperative Extension
no. 23 @clvisory Bulletin

COASTAL CONSTRUCTION PRACTICES

Edited by

Christopher P. Jones
Coastal Engineer
Florida Sea Grant College Program

and

Leigh Taylor Johnson
Brevard County Extension Marine Agent

U . 5 . DEPARTMENT OF COMMERCE NOA A
COASTAL SERVICES CENTER
2234 SOUTH HOBSON AVENUE
CHARLESTON, SC 29405-2413

Project No. A/MAP-l
r1r) Grant.No. NA80AA-D-00038

co Marine Advisory Bulletin MAP-23
Florida Sea Grant College Program

Property of CSC Library

TABLE OF CONTENTS

Introduction . . . . . . . . . . . . . . . . . . . . . . . . .

Problems Encountered by the Building Industry
in Coastal Areas . . . . . . . . . . . . . . . . . . . . . .

Building in Coastal Areas: Siting, Design and
Construction Practices . . . . . . . . . . . . . . . . . . . 4

Protecting Upland Property and Structures . . . . . . . . . . 6

Technical Aspects of Design as Related to the
Coastal Construction Control Line . . . . . . . . . . . . . 11

The Federal Flood Insurance Program . . . . . . . . . . . . . 13

How the City of Cocoa Beach Manages its Shoreline . . . . . . 14

For More Information . . . . . . . . . . . . . . . . . . . . . 16

Florida Sea Grant Marine Advisory Publications . . . . . . . . 18

INTRODUCTION

Coastal construction and development concern us all, especially in
areas where development continues at a rapid pace. Between 1970 and 1980, the
number of households in Florida's coastal counties increased from 1.8 million
to 3.0 million. This continuing growth of coastal areas and the concentration
of people near the ocean's edge indicates a need for up-to-date information on
the problems and technology of building in the coastal zone.

This bulletin contains information from papers presented at a Coastal
Construction Practices Seminar held at Satellite Beach, Florida, on April 12,
1980. The seminar was sponsored by the Brevard County Beach Erosion Control
District, the City of Satellite Beach, the Florida Cooperative Extension
Service and the Florida Sea Grant Program. Although the seminar was organized
to provide a public forum for the citizens of the area to discuss coastal
hazards and coastal construction, the infonnation is applicable to other coastal
areas as well.

Speakers included Dr. Val Villanyi Hausner, consulting engineer,
Orlando; Byron Spangler, professor of civil engineering and Chris Jones, Florida
Sea Grant coastal engineering specialist, both at the University of Florida;
James Balsillie, engineering geologist, Bureau of Beaches and Shores, Florida
Department of Natural Resources, Tallahassee; Jim Smith, Federal Flood Insurance
Program, Federal Emergency Management Agency, Atlanta, Georgia; Ray Murray,
city engineer, Cocoa Beach.

As a supplement to this bulletin, videotapes of the talks by Spangler,
Jones, Balsillie and Smith are available through the Marine Advisory Program.

Leigh Taylor Johnson

Brev ard County Extension Marine Agent

PROBLEMS ENCOUNTERED BY THE
BUILDING INDUSTRY IN COASTAL AREAS

During recent years various regulations have been implemented to pro-
tect Florida's coastal areas. These regulations are based in part upon studies
by the U.S. Amy Corps of Engineers, the Florida Department of Natural Resources,
Universities, local government engineering and building officials and others.

The studies and regulations have addressed two basic problems encountered
in coastal areas:

1. minimizing structural damage to new construction
from wind, surge and wave forces during storms.

2. protecting existing construction against these same
forces.

New construction can, for the most part, be designed to resist hurricane
forces, using existing building codes, flood insurance regulations, setback line
requirements and other available design guidance. Because many existing buildings
were not designed with these requirements and guidance, they cannot be rendered
as storm resistant as new buildings. However, shore protection structures can
be used to prevent a major cause of structural damage and collapse, namely
foundation failure.

Minimizing Damage-to New Construction

From a structural and construction viewpoint, any basic construction
material (wood, masonry, reinforced concrete) can be used for buildings along
the coast provided they are designed properly.

Wood can be an excellent material for lowrise (one and two story) build-
ings as long as it is pressure treated. But the most important requirement for
wood frame construction is that its connections, anchorages and fasteners be
analyzed and designed by a structural engineer to withstand lateral and uplift
wind forces; plywood or wood plank sheeting should cover the stud walls to with-
stand racking forces due to wind pressure. The wood structure itself should be
securely anchored to the foundation.

Masonry construction enables engineers to safely design low to midrise
buildings (eight story maximum). The block walls are reinforced with horizontal
and vertical steel bars spaced at required intervals in concrete filled block
cells. When constructed properly, these buildings will resist vertical gravity
loads and wind loads. Problems do arise, however, when the quality of construc-
tion is substandard. There have been numerous instances where the steel bars
were left out or where the block cells were not filled with concrete, thus
pointing out the need for effective construction inspection.

Reinforced concrete and protected steel buildings can be constructed
to very tall heights and still resist hurricane forces. These are generally con-
structed with shear walls (thick, reinforced concrete walls designed to withstand
hurricane wind forces) that are placed strategically throughout the buildings.
These buildings are generally supported on pilings or other erosion resistant
foundations.

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Regardless of the construction materials used, there are special
consi.derations involved when buil.ding along the coast. The importance of an
adequate foundation and strong connections between structural elements have
already been mentioned. Another important consideration is the specification
of hurricane resistant door, frames, window frames and storTn shutters. Failure
of exterior windows and doors due to wind pressure, suction or projectiles can
lead to other damages.

Protection of Existing Construction

In many cases buildings have been located too close to the shoreline
and are now threatened by erosion. While beach restoration or relocation of the
buildings may be desireable from a geological point of view, these alternatives
may not be feasible or acceptable to the property owners. The only remaining
way to protect existing buildings is with shore protection structures such as
seawalls and revetments.

Many seawalls are really sheet pile bulkheads that serve only as
retaining walls. They can protect against some storms, but numerous failures
have been observed during severe storms. For this reason the term seawall will
be used to describe heavy, structural walls resting on deep foundations, such
as the bayshore seawall protecting the City of Tampa. These walls are very
expensive, frequently costing $400 to $600 or more per linear foot of shoreline.

Riprap revetments are the next best solution and are more affordable,
ilthough they do not provide the same degree of protection. They consist of
one or more layers of natural stone or boulders, concrete rubble or bags filled
with sand-cement grout, placed on a gentle slope. Revetments can be constructed
in front of existing sheet pile walls (to improve wall stability) or by them-
.selves.

The size of the riprap units is determined by the height of the storm
waves expected and the vertical dimensions of the revetment are determined by
the expected stonn surge water level . Design guidance is available in the U.S.
Army, Corps of Engineers Shore Protection Manual.

Dr. Val Villanyi Hausner, consulting engineer, Orlando.

BUILDING IN COASTAL AREAS:
SITING, DESIGN AND CONSTRUCTION PRACTICES

When discussing coastal structures, three topics should be addressed:
siting, design, and construction practices. All three are important in coastal
areas because of the threat of storms and the damage they cause.

A special concern of government officials is the apathy demonstrated by
many coastal citizens. For -instance, although people were evacuated during
Hurricane David in 1979, the storm caused little damage. Next time, those people
may not evaucate. But it is important for them to realize that not all storms
will be like David -- a minimal storm whose track was parallel to the coastline.
In the past, severe hurricanes have come ashore and have caused extensive damage.
It can happen again.

Design maps show that the wind speed corresponding to the 50-year
recurrence interval is approximately 110 miles per hour for most of Florida. The
wind speed corresponding to the 100-year interval is approximately 120 miles
per hour. Two 100-year storms have occurred in the vicinity of Florida since
1934; many storms have exceeded the 50-year design wind speed in that same
period. Thus, severe storms can strike frequently, unlike recent years where
storm activity has been mild.

This becomes important when locating structures along the coastlines.
The relatively mild conditions that have prevailed recently are not always the
case. People who knock down sand dunes in order to build very close to the
beach destroy nature's protective barrier and often replace it with another type
of barrier which is not nearly as resistant to a storm's forces. These forces
include not only wind-, but the more serious storm surge and wave attack.

05114

All of these forces must be considered when designing a structure
for coastal areas. Examples of poor design practices, unfortunately, become
apparent only after a storm -- when the damage has already been done. Hurricanes
Camille (Mississippi, 1969), Eloise (Florida, 1975), and Frederic (Alabama-
Florida, 1979) revealed the following'examples of poor design: inadequate ties
between walls and brick veneers; inadequate fastening of roofs to structures;
insufficient concrete cover over reinforcing steel which allows the steel to
corrode and the structure to be weakened; short wing walls which allow material
to be washed out from behind seawalls; and the use of spread footing foundations
in areas where scour and erosion are expected.

Construction practices are frequently no better. In numerous instances,
reinforcing steel and mesh are not pulled up into the concrete when slabs are
cast. In one case, a support beam was left out when a slab was cast. One of
the most serious deficiencies was uncovered by Hurricane Eloise at a 14-story
condominium under construction at the time of the storm. Approximately one-third
of the pilings beneath the building were exposed by the storm and had no concrete
between the tops of the piles and the bottoms of the grade beams. The building
was resting on the reinforcing steel, which had corroded and lost up to one-half
its cross-section. Another building, through surveying or construction error,
was built so that the bearing walls and pilings were misaligned by six to twelve
inches.

In summary, three specific things need to be considered when building
in coastal- areas. (1) Siting. Buildings should be placed so that they will be
safe during storms. Knocking down sand dunes in order to construct near the
beach is certainly not good practice. (2) Design. Many times designers come
from inland locations where storm surge and wave forces need not be considered.
Not only should these be taken into account, but building code requirements
should be reviewed for often these are inadequate. (3) Finally, construction
must follow designs precisely. Too often short cuts are taken that lead to the
failure of a structure during a storm. Better inspection during construction
is a must.

Byron Spangler, professor of Civil engineering, University of Florida.

PROTECTING UPLAND PROPERTY AND STRUCTURES

Methods of protecting upland property and structures can be divided into
three categories:

I. Management Techniques
II. Non-Structural Techniques
III. Structural Techniques

The first category, Management Techniques, includes such methods
as coastal construction control lines, coastal construction codes, flood in-
surance regulations, etc. These are all aimed at regulating both-the location
and types of construction in the coastal zone; hence, they are most effective
in undeveloped areas.

The Non-Structural Techniques include methods whereby the natural
beach'.and dune system are preserved, enhanced or extended. These techniques
inclVde the beach restoration projects and dune vegetation and stabilization
programs. Structural Techniques include the construction of revetments, sea-
walls and other erosion control structures.

Management Techniques

Coastal construction control lines are established to separate those
portions of the beach and dune system that are susceptible to erosion and other
fluctuations based upon a 100-year ston-n surge, from those portions that are
not. The state must review any construction seaward of the line but has no
authority to regulate construction behind the line.

Coastal construction codes have been established in Lee and Pinellas
Counties in lieu of control line. The coastal area is divided into zones, each
of which has ininimum design standards for construction. The standards are
increasingly stringent as you get closer to the beach, since the potential for
damage increases in the same sense. One advantage of the establishment of codes
(as opposed to a control line) is that the program can be administered locally.

Flood insurance regulations ensure that coastal communities enact
flood plain management guidelines and that construction in flood prone areas
meets minimum requirements (elevation of first habitable floor, structural
support, etc.).

Non-Structural T@@chjjAu(@s

Beach restoration projects involve the dredging of suitable sandy
materials from offshore borrow areas or tidal inlets for placement on adjacent

beaches. The projects usually extend thousands of feet along the shoreline, and
are expensive. As an example, the cities of Hollywood and Hallandale restored
over five miles of beach in 1979, using approximately 2 million cubic yards of
material, at a cost of over $7 million.

Dune vegetation and stabilization programs can be carried out on a
much smaller scale than restoration projects. Basically, the programs involve
the planting of vegetation as a means of stabilizing dunes and sand areas. While
the presence of beach and dune vegetation will not halt erosion, it can
accelerdte the growth of dunes and stablize them. This not only prevents the
loss of windblown sand to inland areas, but acts as a rleans of protecting the
uplands during storms.

Structural Techniques

Structural techniques of protecting upland property and structures
consist mainly of the construction of revetments and seawalls. Their basic func-
tions are to protect against wave attack and to stabilize the position
of the shoreline. Unless properly designed, however, they will not function
as intended, and can have a detrimental effect on the beach, both in front of
and adjacent to the structure.

Revetment and seawall design require an understanding of the following
topics:

1. shoreline dynamics
2. construction materials and structural analysis
3. soil mechanics
4. wave-structure-soil interactions
5. modes of failure

This understanding is necessary to prevent detrimental effects to
adjacent areas and to design the protective structures in a cost-effective manner.

Seawalls

A seawall is usually a vertical wall built of concrete, timber or
steel, which acts'as a retaining wall, holding the material behind it in place,
,qhile resisting wave forces and erosion. Even if a wall remains standing after
a storm, but has failed to prevent the loss of material from behind the wall,
then it has not served its purpose. If the wall itself suffers structural damage
and material is lost, then it has failed.

Seawall failures can generally be divided into five categories, although
a wall may fail in more than one way during storm conditions. Each of these is
discussed below (refer to Figure 1).

1. Loss of Backfill: Material behind a seawall can be lost in
several ways. If joints between the seawall slabs are not tight and if
a filter is not present behind the joints, then the fill can wash through
the joints. If the penetration of the wall into the ground is not

'adequate the material can be washed out beneath the wall Finally, if
the return walls (walls extending landward from the ends of the seawall)
are not long enough, then material can be lost around the ends of the
return walls during storm conditions.
2. Rotation of Wall/Cap: If a seawall is not designed and constructed
to resist the outward-acting forces of the fill behind the wall, then
the top of the wall -will rotate (lean outward).
3. Anchor Failure: If the dead-man or dead-pile anchors behind a
wall fail, the wall will be susceptible to rotation, as discussed
above. Anchors can fail in a number of ways, including: corrosion of
the tie back rod; insufficient development length of the rod into the
cap, in which case it will pull out; if the dead-inan is placed at too
shallow a depth, then it can be pulled through the soil as the wall
rotates.
4. Insufficient Toe Penetration: If the bottom, of the wall does not
have adequate penetration into the ground, then it cannot develop the
resistance necessary to keep the outward-acting forces of the fill
behind the wall from forcing the bottom of the wall outward.
5. Poor Materials, Construction or Design: Deficiencies in materials,
construction techniques or inadequate design can lead to those types of
seawall failures listed above. For example, porous concrete or insuffi-
cient concrete cover over reinforcing steel can lead to corrosion and
spalling, thus reducing the strength of the wall and increasing the
possibility of failure.

LOSS OF BACKFILL ROTATION OF WALL/ CAP

INSUFFICIENT TOE PENETRATION ANCHOR FAILURE

Figure 1: Seawall Failures

Proper design and construction of seawalls can ensure that those
failures mentioned above do not take place. Some general design guidelines for
concrete sheet pile seawalls are mentioned below (refer to Figure 2):

1. Have the seawall designed by a professional engineer.
2. Ensure that construction inspection is provided.
3. Check the design to see that.it provides: adequate concrete cover
over all reinforcing steel in the wall and cap; adequate embedment of
the wall into the cap; adequate penetration of the wall into the ground;
protection of the tie back rod against corrosion; adequate development
length of the tie back rod into the cap; anchors that develop enough
resistance to keep the wall in place.

Provide Adequate Development
Length of Tie Back into Cap

Provide Adequate Embedment
of Wall into Cap

Provide Adequate Concrete Cover
Over Reinforcing Steel in Cap
Place Anchors to Protect Tie Back and Slabs
Develop Maximum Against Corrosion
Pull

hind
Place Filter Cloth Be
Joints in Wall Provide Adequate Toe
Penetration

Figure 2: Seawall Design Considerations anchored
concrete sheet pile seawall

Revetments

Revetments are gradually sloping structures built of stone, inter-
locking blocks and other materials, that are designed to dissipate wave energy
and stabilize the shoreline. They are most effective on low energy coasts and
bay shorelines where wave heights are not large.

Revetment failures can be divided into three categories:

1. Loss of Supporting Material: Revetments depend upon the underlying
material for support. When that material is lost the revetment will
settle and it's effectiveness will be diminished or destroyed.
Anchors tTo@otect Tie B*ackZ""

2. Stones too Small: In the case of a rubble or stone revetment,
failures will occur if the stones are too small and are dislodged by
attacking waves. The size of the ston--s needed increases roughly with
the cube of the ':ave height.
3. Revetment Not Low, High Enough: If the bo-ctcm, of the revetment is
too high, then waves can attack the soil in front of the revetment,
leading to its collapse. If the top of the revetment is too low, then
waves can overtop it easily and erode Lie soil behind the revetment.

Proper design of revetwents includes the following considerations
(refer to Figure 3):

1. Have the revetment designed by a professional engineer.
2. Provide construction inspection.
3. Check the design to ensure that the slope c)f the revetment is not
too steep, that a filter cloth is placed below the stones, that
the stones are of adequate size and weight, and that the vertical
dimensions of the revetment will protect the uplands.

Provide Stone of Adequate
Ensure that pl@ Size and Density
Vertical Dimensions Place Gravel
of Revetment are Layer Over
Adequate Filter Cloth

Grade Soil to
Desired Slope Place Filter Cloth
Under Revetment

Figure 3: Revetment Design Considerations -- Rubble Revetment

Christopher P. Jones, Sea Grant coastal engineering specialist,
University of Florida.

TECHNICAL ASPECTS OFDESIGN AS RELATED TO THE
COASTAL CONSTRUCTION CONTROL LINE

In 1970 the Florida Legislature recognized the need to regulate
coastal construction, both for the protection of that construction and for the
protection of the beach and adjacent property. It enacted section 161.052 of
the Beach and Shore Preservation Act and by doing so prohibited c.onstruction
closer than 50 ft. to the line of mean high water. Because of problems in the
enforcement of section 161.052 (due to the difficulties in delineating the line
of ;nean high water) the legislature enacted 161.053 in 1971, establishing a
coastal construction setback line (CCSBL) on a county by county basis. Once
the line was established all construction and excavation seaward of the line
was prohibited.

In 1978, the setback line program was changed to the Coastal Con@
struction Control Line (CCCL) program, whereby those beach and dune areas subject
to severe fluctuations based upon a 100-year storm surge, or other predictable
weather conditions, were identified. In those areas subject to fluctuation it
was recognized that special structural and design considerations must be applied
before construction or excavation could be allowed. Hence, the CCCL program
does not prohibit construction seaward of the control line, but instead, ensures
that such construction can withstand the forces acting in that region, and
ensures that such construction will not adversely affect the beach or adjacent
property.

In order to properly design structures for those areas seaward of
the control line it is instructive to look at the existing desi.gn guidance (avail-
able in the form of books, reports and technical memoranda) and at the design
event, with its associated design forces.

Currently,books and reports exist providing design guidance for
navigation structures (jetties), shore protection structures (groins, seawalls
and revetments), beach nourishment and revegetation projects, and for non-
protective coastal structures (dune walk-overs, piers, etc.). An example of a
report giving the design information for many of those items mentioned above
is the U. S. Army, Corps of Engineers, Shore Protection Manual.

Unfortunately, there are no comprehensive sources of design guidance
for homes, condominiums and other habitable structures when they are located on
the shoreline. It is hoped that guidelines can be developed in the future
through the Bureau of Beaches and Shores, and be distributed in the fom of
technical memoranda.

The design event commonly used is the 100-year storm, that is, the
story.i that will produce a storm surge that will be exceeded, on the average,
once every 100 years. Identifying the forces associated with this event are
difficult; however, once they are identified the engineering and design work to
be done are relatively straightforward. The forces to be reckoned with include
wind, surge and wave forces.

Wind Force

With regard to the wind forces, the Bureau of Beaches and Shores,
Technical Report No. 78-1, "Design Hurricane Generated Winds," recommends using
a minimum sustained wind of 140 mph for the design of habitable shorefront
construction. A study in Texas indicated that this would increase the cost of
construction from only 0 to 3 percent.

Storm Surge

When a storm approaches the shoreline across shoaling water it experi-,
ences a rise in nearshore water levels due to wind stresses. This departure
from the normal water level is termed the storm surge still water level , or
simply, the storm surge. This rise in water level can lead to flood damage
due to inundation and hydrostatic pressures. Currents occurring within the
storm surge water column can also produce significant hydrodynamic pressures
on structures and result in scour, leading to structural damage. The storm
surge is also very important, since it is the superelevated surface across
which the unusually high storm-generated waves propagate.

Wave Forces

Wave forces are difficult to measure or estimate analytically because
of the complex nature of the water surface and the flow-field beneath the waves,
especially during storm conditions. However, it is known that breaking wave
forces are much greater than those forces from non-breaking or broken waves.
When breaking waves impact directly on a structure the horizontal force can be
approximated by
F = 450 Hb
where F is the horizontal impact force (lbs/ft2) and H is the wave height at
breaking (ft). As you can see, these forces can easil9 reach thousands of
pounds per square foot. Waves can also exert tremendous uplift forces when
they "peak up" just before breaking beneath a structure. Thus, it is necessary
to elevate structures to reduce both the horizontal and vertical forces.

Other effects of waves and surge include the scour of material from
around and beneath structures, horizontal recession of the beach profile (when
the profile is not completely inundated) and vertical recession of the profile
(when it is inundated).

Jim Balsillie, engineering geologist, Bureau of Beaches and Shores, Florida
Department of Natural Resources.

THE FEDERAL FLOOD INSURANCE PROGRAM

Despite early efforts at flood control programs, the amount of federal
disaster assistance for flood damages continued to rise during the 1940's, 1950's
and 1960's. In 1968 Congress enacted the National Flood Insurance Program and
has modified the program several times since then. As the program stands now,
local communities are required to enact flood plain management guidelines, and
any federally regulated lending institution must require that those persons
borrowing money from that institution for construction in flood prone areas
obtain flood insurance.

Flood insurance may be written by any licensed insurance agent, but
all policies are serviced by Electronic Data Systems in Maryland, who act as a
subcontractor to the Flood Insurance Program. Approximately $40 billion in
flood insurance is written in Florida, representing about 30 percent of the
nationwide total .

Once insurance rates are established for an area, they cannot be
increased unless the entire program rate structure is increased (this has
occurred only once in the history of the program). If the base flood elevation
for a particular area is raised, the rates cannot be raised for thatarea alone,

Those areas susceptible to flooding are divided into zones, with
a division between "A" zones and "V" zones. "A" zones are those areas in in-
land or riverine regions where flooding can occur but where high velocity
waters from, waves or currents are not expected. "V" zones, or velocity zones,
are those areas where waves and current occur.

Some "V" zone regulations:

1. All new construction must be landward of the line7of mean high water.
2. As of 1976, fill cannot be used for structural support in a velocity
zone.
3. The lowest supporting member of the first habitable floor must be at
or above the 100-year flood elevation; the area below that must be either
open or enclosed by breakaway-type walls.
4. Man-made alternation of dunes and mangrove stand in the "V" zones
are prohibited if such alterations can increase potential flood damages.
5. All new construction must be on adequately anchored piles or columns,
with the structure fastened to those piles such that the lowest support-
ing member is at or above the flood elevation. In addition, the adequacy
of the structure must be certified by a licensed architect or engineer.
6. Flood Insurance regulations, effective October 1981, require that wave
height be added to the static surge level to determine the base flood
elevation.

Jim 5-nith, Federal Flood Insurance Program, Federal Emergency Management
Agency, Atlanta, Georgia.
13

Editor's Note:

Since the talk by Mr. Smith, there have been soine important changes
in the Flood Insurance Program. Two changes to "V zone regulations,
effective October 1, 1981, are:

(1) All new construction of substantial improvements will receive
cheaper insurance rates if the area below the first habitable
floor either remains completely open or is enclosed by a light,
see-through wooden lattice rather than being enclosed by solid
breakaway walls. This is to discourage past practices of con-
verting the space enclosed by breakaway walls into habitable
space.

(2) Wave height is being added to the static surge level to deter-
mine the elevation of the first habitable floor.

Another change to the program will occur in October 1983, after
which no new flood insurance will be written for un6eveloped barrier
islands.

HOW THE CITY OF COCOA BEACH MANAGES ITS SHORELINE

The city of Cocoa Beach is located on a barrier island, with about
six miles of oceanfront, between Cape Canaveral and Patrick Air Force Base. The
population increases from 12,000 to 22,000 during the tourist season.

The city has taken advantage of rules and regulations provided and
practiced by other communities in developing ordinances regulating coastal con-
struction. Examples of ordinances taken from others, and those formulated by
the city are discussed below.

1. In 1975, the city of Cocoa Beach established a building setback line
co-terminus with the State Coastal Construction Setback Line. Language in
the city ordinance allows for the automatic adoption of any changes in the
state's line. Maps showing the setback line are available for use at the
city building department.
2. All structures in the velocity zone must be constructed on adequately
designed piles, with the design certified by a registered architect or
engineer. All piles must penetrate to at least -4 ft. msl.
3. The density of multi-family developments along the coast was reduced from
40 units per acre to 15 units per acre.
4. In 1978, an ordinance was adopted requiring all new multi-family con-
struction of three or more units to construct dune walkover structures. A
three-year grace period was given to existing multi-family units for their
construction of walkovers.
5. The city participates in the National Flood Insurance Program. The
elevation of the first habitable floor must be at the elevation designated
by the flood insurance program, or one foot above the elevation of the
access road leading to the structure, whichever is higher. The city
engineer may grant a variance to the one-foot rule mentioned, above, but
only for flood management purposes.
6. The city adopted a dune preservation ordinance requiring the replacement-
and revegetation of any dunes damaged during construction on adjacent upland
property.

With regard to enforcement of these ordinances all new construction
must be approved by a site plan review process. Plans must be submitted for
comments by the city and the public (during city planning commission meetings),
and all work must be certified in compliance with plans, specifications and
local ordinances before a certificate of occupancy will be issued.

The area seaward of the setback (control) line is to be handled by
the State of Florida; however, if city inspectors note violations seaward of the
line, the state will be notified.

The city has 40 public beach access points, approximately half of
which have dune walkover structures. Some of these access points are equipped
with viewing decks and handicap ramps.

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The city requested and received funding from the state (a two-year grant
totalling $110,000) for the construction of additional walkovers, revegetation,
etc. Spanish bayonets are usually planted near the walkovers as a means of
controlling pedestrian traffic.

Ray Murray, city engineer, Cocoa Beach, Florida.

FOR MORE INFORMATION

For Information On Contact

Local Ordinances City or County Building and Zoning
Departments

Florida's Coastal Construction Bureau of beaches and Shores
Control Line Program and Permits Florida Department of Natural Resources
for Erosion Control 3900 Commonwealth Blvd.
Tallahassee, FL 32303
(904) 488-3180

Dredge and Fill; Construction Florida Department of Environmental
Seaward of the Mean High Waterline Regulation
2600 Blair Stone Road
Tallahassee, FL 32301
(904) 488-0130

and

U.S. Amy Corps of Engineers
P.O. Box 4970
Jacksonville, FL 32232
(904) 791-3697

Flood Insurance Local Building Department

Federal Emergency Management Agenty
Insurance and Mitigation Division
Suite 77b
1375 Peachtree Street, N.E.
Atlanta, GA 30309
(404) 881-2391

Corps of Engineers Publications U.S. Corps of Engineers
(request a list) Coastal Engineering Research Center
Kingman Bldg.
Ft. Belvoir, VA 22060

For Information On Contact

Florida Sea Grant Publications Local Marine Extension Agent
(See list page 18) and
Assistance or

Florida Sea Grant
BI dg. 803, Room 5
University of Florida
Gainesville, FL 32611
(904) 392-5870

Christopher Jones
Coastal Engineering Specialist
336 Weil Hall
University of Florida
Gainesville, FL 32611
(904) 392-2460; 392-1436

Florida Sea Grant Marine Advisory Public ations

Copies still in print.may be obtained free of charge on a single copy
basis from your local marine extension agent or from:

Marine Advisory Program
G022 McCarty Hall
University of Florida
Gainesville, FL 32611

Fact Sheets

Building Construction on Shoreline Property. Construction guidelines
and considerations for owners, designers and builders of shore area
buildings.

Stabilizing Beaches and Dunes with Vegetation in Florida. MAFS-1. Provides
information on the use of vegetation to stabilize beaches and dunes. Ex-
tracted from Sea Grant Report No. 7, Stabilization of Beaches and Dunes by
Vegetation in Florida, by John H. Davis,'Jr.

Florida Coastal and Environmental Information. MAFS-8. Lists sources of
coastal and environmental information including Coastal Engineering Archives,
Environmental Data Index, Oceanic and Atmospheric Scientific Information
Center, University of Florida computer searches, etc.

Bulletins

hurricane-Resistant Construction for Homes. MAP-16 (Formerly SUSF-SG-76-005).
31 pp. Discusses hurricane Winds and the implication of probability concepts
on 'home design in hazardous areas. Federal and local guidelines are reviewed
including the National Flood Insurance Program, the Florida Coastal Construc-
tion Setback Line, and county building codes.

Beach Dune Walkover Structures. MAP-18 (Formerly SUSF-SG-76-006). 13 pp.
Information and instructions for building walkover structures in areas where
sand dunes are threatened by human-traffic.

Reports

Seawall and Revetment Effectiveness, Cost and Construction. Report No. 6.
52 pp. Explains the types of shore protection structures commonly available
and the relative merits and costs of each.

Stabilization of Beaches and Dunes by Vegetation in Florida. Report No. 7.
52 pp. Provides coastal strand property owners and managers with guidelines
for use of vegetation in the protection and restoration of Florida beaches.,

Seawall Design on the Open Coast. Report No. 29. 24 pp. Provides insight into
effects which seawalls have on the beach system, and proper design considera-
tions for seawall construction on the open coast.

Florida Sea Grant College is supported by award of the Office of Sea
Grant, National Oceanic and Atmospheric Administration, U. S. Depart-
ment of Commerce, grant number NA80AA-D-00038, under provisions of the
National Sea Grant College and Programs Act of 1966. This information
is published by the-Marine Advisory Program which functions as a com-
ponent of the University of Florida Cooperative Extension Service,
John T. Woeste, dean, in conducting Cooperative Extension work in
Agriculture, Home Economics, and Marine Sciences, State of Florida,
U.S. Department of Agriculture, U.S. Department of Commerce, and
Boards of County Commissioners, cooperating. Printed and distributed
in furtherance of the Acts of Congress of May 8 and June 14, 1914.
The Florida Sea Grant College is an Equal Employment Opportunity-
Affirmative Action employer authorized to provide research, educational
information and other services only to individuals and institutions that
function without regard to race, color, sex, or national origina.

1/1.5M/82

DATE DUE

ervice

This public documen 58 or 2j
cents per cop ns inter-
ested in coastal cdI

GAYLORD No. 2333 PRINTED IN U.S.A.

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