In all areas of special flood hazards the following provisions
are required for all new construction and substantial improvements:
(1) All new construction or substantial improvements shall be designed
(or modified) and adequately anchored to prevent flotation, collapse
or lateral movement of the structure resulting from hydrodynamic and
hydrostatic loads, including the effects of buoyancy;
(2) All new construction or substantial improvements shall be constructed
by methods and practices that minimize flood damage;
(3) All new construction or substantial improvements shall be constructed
with materials resistant to flood damage;
(4) All new construction or substantial improvements shall be constructed
with electrical, heating, ventilation, plumbing, and air-conditioning
equipment and other service facilities that are designed and/or located
so as to prevent water from entering or accumulating within the components
during conditions of flooding;
(5) All new and replacement water supply systems shall be designed to
minimize or eliminate infiltration of floodwaters into the system;
(6) New and replacement sanitary sewage systems shall be designed to
minimize or eliminate infiltration of floodwaters into the system
and discharge from the systems into floodwaters; and
(7) On-site waste disposal systems shall be located to avoid impairment
to them or contamination from them during flooding.
(Ordinance 2010-05 adopted 8/3/10; Ordinance
2024-3 adopted 1/8/2024)
When a residential or nonresidential structure is intended to
be constructed in an approximate A zone, a BFE must be determined
by using the same engineering standards and methods that are used
to develop BFEs in a flood insurance study (FIS). In all areas of
special flood hazards where base flood elevation data has been provided
as set forth in section 3.607, section 3.632(8), or section 3.653(c),
the following provisions are required:
(1) Residential construction.
New construction and substantial
improvement of any residential structure shall have the lowest floor
(including basement), elevated to a minimum of 12 inches or 1 foot
above the base flood elevation. A registered professional engineer,
architect, or land surveyor shall submit a certification to the floodplain
administrator that the standard of this subsection as proposed in
section 3.633(a)(1), is satisfied.
(A)
If a new or substantially improved residential structure is
constructed outside the SFHA but is within 1 foot of the centerline
of a known but unmapped watercourse (including an intermittent watercourse
on the community's FIRM, then it shall be elevated so that the
lowest floor (including basement) is a minimum of 12 inches or 1 foot
above the highest adjacent grade.
(B)
All residential structures that are constructed outside the
SFHA shall be elevated 12 inches or 1 foot above the highest adjacent
grade.
(2) Nonresidential construction.
New construction and substantial
improvements of any commercial, industrial or other nonresidential
structure shall either have the lowest floor (including basement)
elevated to a minimum of 12 inches or 1 foot above the base flood
elevation or together with attendant utility and sanitary facilities,
be designed so that below the base flood elevation level the structure
is watertight to a minimum level of 12 inches or 1 foot above the
BFE with walls substantially impermeable to the passage of water and
with structural components having the capability of resisting hydrostatic
and hydrodynamic loads and effects of buoyancy. A registered professional
engineer or architect shall develop and/or review structural design,
specifications, and plans for the construction, and shall certify
that the design and methods of construction are in accordance with
accepted standards of practice as outlined in this subsection. A record
of such certification which includes the specific elevation (in relation
to mean sea level) to which such structures are floodproofed shall
be maintained by the floodplain administrator.
(3) Enclosures.
New construction and substantial improvements,
with fully enclosed areas below the lowest floor that are usable solely
for parking of vehicles, building access or storage in an area other
than a basement and which are subject to flooding shall be designed
to automatically equalize hydrostatic flood forces on exterior walls
by allowing for the entry and exit of floodwaters. Designs for meeting
this requirement must either be certified by a registered professional
engineer or architect or meet or exceed the following minimum criteria:
(A)
A minimum of two openings on separate walls having a total net
area of not less than 1 square inch for every square foot of enclosed
area subject to flooding shall be provided.
(B)
The bottom of all openings shall be no higher than 1 foot above
grade.
(C)
Openings may be equipped with screens, louvers, valves, or other
coverings or devices provided that they permit the automatic entry
and exit of floodwaters.
(4) Manufactured homes.
(A)
Require that all manufactured homes to be placed within zone
A on a community's FHBM or FIRM shall be installed using methods
and practices which minimize flood damage. For the purposes of this
requirement, manufactured homes must be elevated and anchored to resist
flotation, collapse, or lateral movement. Methods of anchoring may
include, but are not limited to, use of over-the-top or frame ties
to ground anchors. This requirement is in addition to applicable state
and local anchoring requirements for resisting wind forces.
(B)
Require that manufactured homes that are placed or substantially
improved within zones A1-30, AH, and AE on the community's FIRM
on sites:
(i)
Outside of a manufactured home park or subdivision;
(ii)
In a new manufactured home park or subdivision;
(iii) In an expansion to an existing manufactured home
park or subdivision; or
(iv)
In an existing manufactured home park or subdivision on which
a manufactured home has incurred substantial damage as a result of
a flood;
be elevated on a permanent foundation such that the lowest floor
of the manufactured home is elevated to a minimum of 12 inches or
1 foot above the base flood elevation and be securely anchored to
an adequately anchored foundation system to resist flotation, collapse,
and lateral movement.
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(C)
Require that manufactured homes be placed or substantially improved
on sites in an existing manufactured home park or subdivision with
zones A1-30, AH and AE on the community's FIRM that are not subject
to the provisions of subsection (4) of this section be elevated so
that either:
(i)
The lowest floor of the manufactured home is elevated to a minimum
of 12 inches or 1 foot above the base flood level; or
(ii)
The manufactured home chassis is supported by reinforced piers
or other foundation elements of at least equivalent strength that
are no less than 36 inches in height above grade and be securely anchored
to an adequately anchored foundation system to resist flotation, collapse,
and lateral movement.
(5) Recreational vehicles.
Require that recreational vehicles
placed on sites within zones A1-30, AH, and AE on the community's
FIRM either:
(A)
Be on the site for fewer than 180 consecutive days; or
(B)
Be fully licensed and ready for highway use; or
(C)
Meet the permit requirements of section 3.633(a), and the elevation
and anchoring requirements for manufactured homes in subsection (4)
of this section.
A recreational vehicle is ready for highway use if it is on
its wheels or jacking system, is attached to the site only by quick
disconnect type utilities and security devices, and has no permanently
attached additions.
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(Ordinance 2010-05 adopted 8/3/10; Ordinance 2020-2 adopted 1/9/20; Ordinance 2024-3 adopted 1/8/2024)
(a) All subdivision proposals including the placement of manufactured
home parks and subdivisions shall be consistent with sections 3.602,
3.603, and 3.604 of this article.
(b) All proposals for the development of subdivisions including the placement
of manufactured home parks and subdivisions shall meet floodplain
development permit requirements of section 3.608, section 3.633; and
the provisions of this division.
(c) Base flood elevation data shall be generated for subdivision proposals
and other proposed development including the placement of manufactured
home parks and subdivisions which is greater than 50 lots or 5 acres,
whichever is lesser, if not otherwise provided pursuant to section
3.607 or section 3.632(8) of this article.
(d) All subdivision proposals including the placement of manufactured
home parks and subdivisions shall have adequate drainage provided
to reduce exposure to flood hazards.
(e) All subdivision proposals including the placement of manufactured
home parks and subdivisions shall have public utilities and facilities
such as sewer, gas, electrical and water systems located and constructed
to minimize or eliminate flood damage.
(Ordinance 2010-05 adopted 8/3/10; Ordinance
2024-3 adopted 1/8/2024)
Located within the areas of special flood hazard established
in section 3.607, are areas designated as shallow flooding. These
areas have special flood hazards associated with flood depths of 1
to 3 feet where a clearly defined channel does not exist, where the
path of flooding is unpredictable, and where velocity flow may be
evident. Such flooding is characterized by ponding or sheet flow;
therefore, the following provisions apply:
(1) All new construction and substantial improvements of residential
structures have the lowest floor (including basement) elevated to
a minimum of 12 inches or 1 foot above the base flood level or the
highest adjacent grade at least as high as the depth number specified
in feet on the community's FIRM (at least 2 feet if no depth
number is specified). They also shall have the ductwork, and exposed
plumbing and electrical components elevated 12 inches or 1 foot above
the BFE.
(2) All new construction and substantial improvements of nonresidential
structures:
(A)
Have the lowest floor (including basement) elevated to or above
the base flood elevation or the highest adjacent grade at least as
high as the depth number specified in feet on the community's
FIRM (at least 2 feet if no depth number is specified); or
(B)
Together with attendant utility and sanitary facilities be designed
so that below the base specified flood depth in an AO zone, or below
the base flood elevation in an AH zone, level the structure is watertight
with walls substantially impermeable to the passage of water and with
structural components having the capability of resisting hydrostatic
and hydrodynamic loads of effects of buoyancy.
(3) A registered professional engineer or architect shall submit a certification
to the floodplain administrator that the standards of this section,
as proposed in section 3.633(a)(3), are satisfied.
(4) Require within zones AH or AO adequate drainage paths around structures
on slopes, to guide floodwaters around and away from proposed structures.
(Ordinance 2010-05 adopted 8/3/10; Ordinance 2020-2 adopted 1/9/20; Ordinance 2024-3 adopted 1/8/2024)
Located within areas of special flood hazard established in
section 3.607 are areas designated as floodways. Since the floodway
is an extremely hazardous area due to the velocity of floodwaters
which carry debris, potential projectiles and erosion potential, the
following provisions shall apply:
(1) Fill material of any kind is prohibited within the regulatory floodway
as delineated on the community's FIRM.
(2) Encroachments are prohibited, including fill, new construction, substantial
improvements and other development within the adopted regulatory floodway
unless it has been demonstrated through hydrologic and hydraulic analyses
performed in accordance with standard engineering practice that the
proposed encroachment would not result in any increase in flood levels
within the community during the occurrence of the base flood discharge.
(3) If subsection
(1) above is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of this division.
(4) Under the provisions of 44 CFR chapter
1, section 65.12, of the National Flood Insurance Program regulations, a community may permit encroachments within the adopted regulatory floodway that would result in an increase in base flood elevations, provided that the community first completes all of the provisions required by section 65.12.
(Ordinance 2020-2 adopted 1/9/20; Ordinance
2024-3 adopted 1/8/2024)