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 adopted 1/12/10)
In all areas of special flood hazards where base flood elevation data has been provided as set forth in section 3.06.006, section 3.06.042(8) or section 3.06.073(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 2 feet 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 3.06.043(a)(1), is satisfied.
(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 2 feet above the base flood level or together with attendant
utility and sanitary facilities, be designed so that below the base
flood 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 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 FIRM shall be installed using methods and practices
that 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 2 feet above the base
flood elevation and be securely anchored to an adequately anchored
foundation system to resist flotation, collapse, and lateral movement.
(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 at 2 feet above the
base flood elevation; 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.
(Ordinance adopted 1/12/10)
(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 3.06.006 or section 3.06.042 of this article.
(d)
Base
flood elevation data shall be generated by a detailed engineering
study for all zone A areas, within 100 feet of the contour lines of
zone A areas, and other streams not mapped by FEMA, as indicated on
the community’s FIRM.
(e)
All
subdivision proposals including the placement of manufactured home,
parks and subdivisions shall have adequate drainage provided to reduce
exposure to flood hazards.
(f)
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 adopted 1/12/10)
