12-86 ORDIllANCE NO, 12-86
AN ORDINANCE OF THE CITY COUNCIL OF TEE CITY OF
DELRAY BEACH, FLORIDA, AMENDING CHAPTER 9; 'BUILD-
INGS AND CONSTRUCTION', OF THE CODE OF ORDINANCES OF
THE CITY OF DELRAY BEACH, FLORIDA, BY ENACTING A NEW
ARTICLE IX, 'COASTAL CONSTRUCTION CODE', TO PROVIDE
A TITLE, TO PROVIDE A GENERAL PURPOSE, TO PROVIDE
THE APPLICABILITY AND SCOPE' OF THE COASTAL CONSTRUC-
TION CODE, TO PROVIDE POR THE APPLICABILITY TO
EXISTING STRUCTURES, TO PROVIDE FOR THE APPLICA-
BILITY TO MULTI-ZONE STRUCTURES, TO PROVIDE FOR
EXEMPTION OF CONSTRUCTION WHICH EXTENDS SEAWARD OF
THE MEAN HIGH WATER LINE, TO PROVIDE FOR APPLICA-
TIONS FOR PERMITS, TO PROVIDE FOR DEFINITIONS, TO
PROVIDE GENERALLY FOR COASTAL CONSTRUCTION REQUIRE-
MENTS, TO PROVIDE FOR STRUCTURAL REQUIREMENTS FOR
MAJOR STRUCTURES, TO PROVIDE FOR STRUCTURAL REQUIRE-
MENTS FOR NONHABITABLE MAJOR STRUCTURES, TO PROVIDE
FOR STRUCTURAL REQUIREMENTS FOR MINOR STRUCTURES, TO
PROVIDE FOR LOCATION OF CONSTRUCTION, TO PROVIDE FOR
PUBLIC ACCESS, AND TO PROVIDE REFERENCES FOR
ASSISTANCE IN DETERMINING DESIGN PARAMETERS AND
METHODOLOGIES FOR COMPLIAHCE~ PROVIDING A GENERAL
REPEALER~ PROVIDING A SAVING CLAUSE~' PROVIDING AN
EFFECTIVE DATE.
WHEREAS, the City Council of the City of Delray Beach, Florida
wishes to implement those provisions of the 'Coastal Zone Protection Act
of 1985'~ and,
WHEREAS, the Department of Community Affairs has developed a
model coastal construction code which fulfills the requirements of the
new law~ and,
WHEREAS, each. affected local government must adopt its own
coastal building code prior to March 1, 1986~ and,
WHEREAS, this model code is the product of a working group
comprised of engineering, architectural, and construction interests,
local government interests, commercial interests, state agencies,
environmental interests, and others~ and,
WHEREAS, although the Coastal Zone Protection Act of 1985 may
undergo some slight revision in the upcoming Legislative session, this
model code is the e~bodiment of the best implementation of the Act at
this time for all concerned interests.
NOW, THEREFORE, BE IT ORDAINED BY THE CITY COUNCIL OP THE CITY
OP DELRAY BEACH, FLORIDA, AS FOLLOWS:
~F, JL~. That Chapter 9, 'Buildings and Construction', of
the Code of Ordinances of the City of Delray Beach, Florida, be and the
same is hereby amended by enacting a new Article IX, 'Coastal Construc-
tion Code' to read as follows:
ARTICLE IX. cOASTAL CONSTRUCTION CODE
Sec. 9-590. Title.
The provisions contained herein shall constitute the Coastal
Construction Code for construction within the coastal building zone the
City of Delray Beach, Florida, and shall be referred to as the 'Coastal
Construction Code.'
Sec. 9-591. General purpose.
The purpose of the Coastal Code is to provide minimum standards for
the design and construction of buildings and structures to reduce the
harmful effects of hurricanes and other natural disasters occurring
along the coastal areas of which front on the Atlantic Ocean. These
standards are intended to specifically address design features which
affect the structural stability of the beach, dunes, and topography of
adjacent properties. The Coastal Code is site specific to the coastal
building zone as defined herein and is not applicable to other
locations. In the event of a conflict between this chapter and other
chapters of this code, the requirements resulting in more restrictive
design shall apply. No provisions in this chapter shall be construed to
permit any construction in any area prohibited by local city, county or
state regulation.
Sec. 9-592. Applicability and scope.
The requirements of this Coastal Code shall apply to the following
types of construction in the coastal building zone in the City of Delray
Beach, Florida.
(a) The new construction of, or improvement of major structures,
nonhabitable major structures, and minor structures as defined herein.
(b) Construction which would change or alter the character of the
shoreline (e.g. excavation, grading, paving). The Coastal Code does not
apply to minor work in the nature of normal beach cleaning or debris
removal.
Sec. 9-593. Applicability to existing structures.
The requirements of this chapter shall not apply to existing
structures, structures under construction, or structures for which a
valid an unexpired municipal or county building permit was issued prior
to the adoption of the Coastal Code.
Sec. 9-594. Multi-Zone structures.
For structures located partially in the coastal building zone, the
requirements of the Coastal Code shall apply to the entire structure.
Sec. 9-595. Construction seaward of mean high water.
Structures or construction extending seaward of the mean high water
line which are regulated by Section 161.041, Florida Statutes, (e.g.,
groins, jetties, moles, breakwaters, seawalls, revetments, beach
nourishment, inlet dredging, etc.), are specifically exempt from the
provisions of this chapter. In addition, the Coastal Code does not
apply to piers, pipelines, or outfalls which are regulated pursuant to
the provisions of Section 161.053, Florida Statutes.
Sec. 9-596. Applications for permits.
Applications for building permits for all construction in the
coastal building zone and on coastal barrier islands, if not of normal
or usual design as determined by the Building Official, shall be
certified by an architect or professional engineer registered in the
State of Florida. Such certification shall state that the design plans
and specifications for the construction are in compliance with the
criteria established by this Coastal Code.
sec. 9-597. Definitions.
The following terms are defined for general use in the Coastal
Code.
2 ORD. NO. 12-86
(a) 'Beach' means the zone of unconsolidated material that extends
landward from the mean low water line to the place where there is marked
change in material or physiographic form, or to the line of permanent
vegetation, usually the effective limit of storm waves. 'Beach' is
alternatively termed 'shore.'
(b) 'Breakaway wall' or frangible wall' means a partition indepen-
dent of supporting structural members that will withstand design wind
forces, but will fail under hydrostatic, wave, and runup forces
associated with the design storm surge. Under such conditions, the wall
shall fail in a manner such that it breaks up into components that will
minimize the potential for damage to life or adjacent property.
(c) 'Building Support Structure' means any structure which
supports floor, wall or column loads, and transmits them to the founda-
tion. The term shall include beams, grade beams, or joists, and
includes the lowest horizontal structural member exclusive of piles,
columns, or footings,
(d) 'Coastal Barrier Islands' means geological features which are
completely surrounded by marine waters that front upon the open waters
of the Gulf of Mexico, Atlantic Ocean, Florida Bay, or Strait of Florida
and are composed of quartz sands, clays, limestone, oolites, rock,
coral, coquina, sediment, or other material, including soil disposal,
which features lie above the line of mean high water. Mainland areas
which were separated from the mainland by artificial channelization for
the purpose of assisting marine commerce shall not be considered coastal
barrier islands.
(e) "Coastal Building Zone" means the land area from the seasonal
high water line to a line 1500 feet landward of the coastal construction
control line established pursuant to Section 161.053, Florida Statutes.
For those coastal cities and counties for which no coastal construction
control line has been established, the "coastal building zone" is
defined as that land area 3000 feet landward from the mean high water
line. On coastal barrier islands, the "coastal building zone" is
defined as the area 5000 feet landward from the coastal construction
control line or the entire island whichever is less. On barrier islands
for which no coastal construction control line has been established the
"coastal building zone" is the area 5000 feet landward from the mean
high water line or the entire island, whichever is less.
(f) "Column Action" means the potential elastic instability in
piles or columns resulting in axial or lateral bending of the member due
to compressive stress.
(g) "Construction" means the carrying out of any building, clear-
ing, filling, or excavation or the making of any material change in the
size or use of any structure or the appearance of any land. When
appropriate to the context, "construction" refers to the act of
construction or the result of construction.
(h) "Dune" means a mound or ridge or loose sediments, usually
sand-sized, lying landward of the beach, and deposited by natural or
artificial means.
(i) "Major Structure" includes but is not limited to residential
buildings including mobile homes, commercial, institutional, industrial,
and other construction having the potential for substantial impact on
coastal zones.
(j) "Mean High Water Line" means the intersection of the tidal
plane of mean high water with the shore. Man high water is the average
height of high waters over a 19-year period. (See Section 177.27(15),
F.S.).
3 ORD. NO. 12-86
(k) 'Minor Structure' includes but is not limited to
pile-supported, elevated dune and beach walkover structures~ .beach
access ramps and walkways~ stairways~ pile-supported elevated viewing
platforms, gazebos, and boardwalks~ lifeguard support stands~ public
and private bathhouses~ sidewalks, driveways, parking areas, shuffle-
board courts, tennis courts, handball courts, racquetball courts, and
other uncovered paved areas~ earth retaining walls, sand fences, privacy
fences, ornamental walls, ornamental garden structures, aviaries, and
other ornamental construction. It shall be a characteristic of minor
structures that they are considered to be expendable under design wind,
wave, and storm forces.
(1) 'Nonhabitable Major Structure' includes but is not limited to
swimming pools~ parking garages~ pipelines~ piers~ canals, lakes,
ditches, drainage structures, and other water power plants, transmission
and distribution lines, transformer pads, vaults, and substations~
roads, bridges, streets, and highways~ underground storage tanks~
communications buildings and towers~ flagpoles and signs over 15 feet in
height.
(m) 'NGVD' means National Geodetic Vertical Datum - a geodetic
datum established by the National Ocean Services and frequently referred
to as the 1929 Mean Sea Level Datum.
(n) 'Seasonal high water line~ means the line formed by the
intersection of the rising shore and the elevation of 150 percent of the
local mean tidal range above local mean high water.
Sec. 9-598. Coastal construction requirements generally.
Construction within the coastal building zone and on coastal
barrier islands shall meet the requirements of this chapter. All
structures shall be designed so as to minimize damage to life, property,
and the natural environment. Assistance in determining the design
parameters to minimize such damage may be found in the reference docu-
ments listed in Section 9-604.
Sec. 9-599. Structural requirements for major structures.
(a) Foundations
All major structures shall be anchored to their foundations in such
a manner as to prevent flotation, collapse, or lateral displacement.
Foundation design and construction shall consider all anticipated
loads resulting from design storm conditions, including wave, hydro-
dynamic, hydrostatic, and wind loads acting simultaneously with dead
loads. Erosion computations for foundation design shall account for all
vertical and lateral erosion and scour-producing forces, including
localized scour due to the presence of structural components.
1. Pile Foundations - shall be required for buildings
located in Federal Emergency
Management ~gency Flood Insurance
Rate Map 'V' (velocity) zones or
where impacted by wave action.
(A) Pile dimensions, spacing and embedment shall be
designed consistent with the requirements of the
site, taking into account all vertical, lateral,
erosion and scour-producing forces.
(B) Piles shall be driven to a penetration'which
achieves adequate bearing capacity taking into
consideration the anticipated loss of sot1 above
the design grade.
4 ORD. NO. 12-86
(C) In addition to the normal foundation analysts, the
pile foundation analysis shall consider piles in
column action, where appropriate, from the bottom
of the support structure to the design grade.
(D) Consideration shall also be given to the degree of
exposure to wave attack and the resulting impact
loads on lateral or diagonal bracing between piles.
2. Conventional or Monolithic Foundations - may be permitted in
Federal
Emergency Management Agency
Flood Insurance Rate Map
"A" or "B" zones or in
locations not impacted by
wave action.
(A) Conventional or monolithic foundations may be used if
soil conditions permit and if located at an elevation
which minimizes their effect on the beach and
adjacent properties. Due consideration shall be
given to their vulnerability to erosion under
design storm conditions.
(B) In the event that a conventional or monolithic foundation is
used, the maximum elevation of the top of the footing slab
is to be below the design scour depth (see Chapter 5.28,
Shore Protection Manual, U.S. Army Crops of Engineers, 4th
edition, 1984} unless positive methods are provided to
prevent scour.
(C) Other types of spread footings such as running footers or
pads may be permitted when positive methods are provided to
prevent scour or when the top of the footings are at or
below design scour depth.
(b) Understructures
No substantial walls or partitions shall be constructed below the
level of the first finished floor. This does not preclude the construc-
tion of=
1. Stairways;
2. Shearwalls essentially perpendicular to breaking waves;
3. Shearwalls essentially parallel to breaking waves which do not
exceed a maximum of 20% of the building length;
4. Wind or sand screens constructed of fabric or wire mesh;
5. Light open lattice partitions with individual wooden lattice
strips no greater than 3/4" thick or 3" wide;
6. Elevator shafts;
7. Breakaway or frangible walls; or
8. Substantial walls constructed above the wave action and storm
surge expected under design storm conditions.
(c) Building and Floor Elevations
The minimum elevation for the underside of the building support
structure (excluding foundation) shall be above the elevation of the
design breaking wave crests or wave uprush superimposed on the storm
5 ORD. NO. 12-86
surge with dynamic wave setup expected under design storm conditions.
The elevation of the storm surge with dynamic wave setup shall be either
the elevation established by the Florida Department of Natural Resources
Coastal Construction Control Line Study for that portion east of the
coastal construction control line or the base flood elevation for the
specific area established by the Federal Emergency Management Agency as
determined by the design engineer and as indicated on the flood
insurance rate map.
(d) Erosion and Design Grade
The elevation of the soil surface to be used in the design of
foundations, calculation of pile reactions and bearing capacities shall
not be greater than that which would result from the erosion reasonably
anticipated as a result of design storm conditions. Calculation of the
design grade shall take into account localized scour due to the presence
of structural components. Erosion computations for foundation design
shall consider all vertical and lateral erosion and scour-producing
forces.
(e) Wave Force Design
1. Calculations for wave forces resulting from design storm
conditions on building foundations and superstructures may be based upon
the minimum criteria and methods prescribed in the Naval Facilities
Engineering Command Design Manual, NAVFAC DM26, U.S. Department of Navy~
Shore Protection Manual U.S. Department of the Army Corps of Engineers~
U.S. Department of the Army Coastal Engineering Research Center Tech-
nical Papers and Reports~ the Technical and Design Memoranda of the
Division of.Beaches and Shores, Florida Department of Natural Resources~
or other professionally recognized methodologies which produce equiva-
lent design criteria.
2. Breaking, broken, and nonbreaking waves shall be considered as
applicable. Design wave loading analysis shall consider vertical uplift
pressures and all lateral pressures to include impact as well as dynamic
loading and the harmonic intensification resulting from repetitive
waves.
(f) Hydrostatic Loads
Calculations for hydrostatic loads shall consider the maximum water
pressure resulting from a fully peaked, breaking wave superimposed upon
the design storm surge with dynamic wave setup. Both free and
hydrostatic loads shall be considered. Hydrostatic loads which are
confined shall be determined using the maximum elevation to which the
confined water would freely rise if unconfined. Vertical hydrostatic
loads shall be considered both vertically downward and upward on
horizontal or inclined surfaces of major structures (e.g., floors,
slabs, roofs, walls). Lateral hydrostatic loads shall be considered as
forces acting horizontally above and below grade on vertical or inclined
surfaces. Hydrostatic loads on irregular or curved geometric surfaces
shall be determined by considering the separate vertical and horizontal
components acting simultaneously under the distribution of the
hydrostatic pressures.
(g) Hydrodynamic Loads
Hydrodynamic loads shall consider the maximum water pressures
resulting from the motion of the water mass associated with the design
storm. Full intensity loading shall be applied on all structural
surfaces above the design grade which would affect the flow velocities.
(h) Design Conditions - General
6 ORD. NO. 12-86
1. Foundations for all major structures shall be designed for the
horizontal and vertical pressures generated by wave forces between the
elevation of the design breaking wave crests or wave uprush superimposed
upon the storm surge and the stable soil elevation of the site.
2. All major structures, except mobile homes, shall be designed
to withstand 140 mph windspeeds. Horizontal wind velocity pressures
shall not be less than the values given below:
BASIC WIND VELOCITY DESIGN PRESSURE
(Pounds per Square Foot)
Standard Building Code
Height Pressure
0-30 41
31-50 54
51-100 65
101-200 79
201-300 92
301-400 101
401-500 109
501-800 121
801-1000 133
over 1000 137
*The above table is based upon the formula P =.00256 X V X
(H/30) 2/7, where: P = pressure in pounds/square foot V ~ 140 mph
H = height above grade in feet
3. Appropriate shape factors shall be applied for resistance
against overturning and uplift as required elsewhere in this code and as
further described in the Standard Building-Code. Internal pressures on
internal walls, ceilings and floors resulting from damaged windows or
doors shall also be considered in the design unless the specific windows
and doors have been tested by an approved testing agency and have been
shown to be capable of withstanding the design pressures required
herein.
4. Mobile homes shall conform to the Federal Mobile Home
Construction and Safety Standards of the Uniform Standards Code ANSI
book Allg.1, pursuant to s. 320.823, Florida Statutes, in addition to
the other requirements contained in this chapter.
Sec. 9-600. Structural requirements for nonhabitable major structures.
Nonhabitable major structures need not meet the specific structural
requirements of Section 9-599, except that they shall be designed to
produce the minimum adverse impact on the beach and dune system and
shall comply with the applicable standards of construction found
elsewhere in this code and as required by the Standard Building Code.
All sewage treatment and public water supply systems shall be
flood-proofed to prevent infiltration of surface water anticipated under
design storm conditions. Underground utilities, excluding pad trans-
formers and vaults, shall be flood-proofed to prevent infiltration of
surface water expected under design storm conditions or shall otherwise
he'designed to function when submerged under such storm conditions.
Sec. 9-601. Structural requirements for minor structures.
7 ORD. NO. 12-86
Minor structures need not meet the specific structural requirements
of Section 9-599, except that they shall be designed to produce the
minimum adverse impact on the beach and dune system and shall comply
with the applicable standards of construction found elsewhere in this
code and as required by the Standard Building Code.
Sec. 9-602. Location of construction.
Construct.ion, except for elevated walkways, lifeguard support
stands, piers, beach access ramps, gazebos, and coastal or shore protec-
tion structures, shall be located a sufficient distance landward of the
beach to permit natural shoreline fluctuations and to preserve dune
stability. Construction, including excavation, may occur to the extent
that the natural storm buffering and protection capability of the dune
is not diminished.
Sec. 9-603. Public access.
Where the public has established an accessway through private lands
to lands seaward of mean high tide or water line by prescription,
prescriptive easement, or any other legal means, development or
construction shall not interfere with such right of access unless a
comparable alternative accessway is provided. The developer shall have
the right to improve, consolidate, or relocate such public accessways so
long as they are:
(a) Of substantially similar quality and convenience to
the publicl
(b) Approved by the local government~ and
(c) Consistent with he coastal management element of
the local comprehensive plan adopted pursuant to
Section 163.3178, Florida Statutes.
Sec. 9-604. References.
Assistance in determining the design parameters and methodologies
necessary to comply with the requirements of this chapter may be
obtained form:
Shore Protection Manual, U.S. Army Corps of Engineers, 4th
edition, 1984.
U.S. Department of the Army, Coastal Engineering Research
Center's Technical Papers and Reports.
Florida Department of Natural Resources, Division of
Beaches and Shores Technical and Design Memoranda.
Naval Facilities Engineering Command Design Manual, NAVFAC
DM-26, U.S. Department of the Navy.
~. That all ordinances or parts of ordinances which
are in conflict herewith are hereby repealed.
~. That should any section or provision of this
ordinance or any portion thereof, any paragraph, sentence, or word be
declared by a court of competent jurisdiction to be invalid, such
decision shall not affect the validity of the remainder hereof as a
whole or part thereof other than the part declared to be invalid.
~. That this ordinance shall become effective on
March 1, 1986.
8 ORD. NO. 12-86
PASSED ARD ~O~ED in regular session on second and final
reading on this the 25th day of Feb~~1986___~.
'-~A~O~
A~EST ~
City~erk
First Reading February 11, 1986
Second Reading February 25, 1986
9 ORD. NO. 12-86