The following standards apply to new development, including new and substantially improved structures, in the areas of special flood hazard shown on the Flood Insurance Rate Map designated in § 93-6.
The following standards apply to all new subdivision proposals
and other proposed development in areas of special flood hazard, including
proposals for manufactured home and recreational vehicle parks and
subdivisions:
A.
Within Zones A1-A30 and AE, on streams without a regulatory floodway,
no new construction, substantial improvements or other development,
including fill, shall be permitted unless:
(1)
The applicant demonstrates that the cumulative effect of the proposed
development, when combined with all other existing and anticipated
development, will not increase the water surface elevation of the
base flood more than one foot at any location; or
(2)
The Village of Livonia agrees to apply to the Federal Emergency Management
Agency (FEMA) for a conditional FIRM revision, FEMA approval is received,
and the applicant provides all necessary data, analyses and mapping
and reimburses the Village for all fees and other costs in relation
to the application. The applicant must also provide all data, analyses
and mapping and reimburse the Village of Livonia for all costs related
to the final map revision.
B.
On streams with a regulatory floodway, as shown on the Flood Boundary and Floodway Map or the Flood Insurance Rate Map adopted in § 93-6, no new construction, substantial improvements or other development in the floodway, including fill, shall be permitted unless:
(1)
A technical evaluation by a licensed professional engineer shows
that such an encroachment shall not result in any increase in flood
levels during occurrence of the base flood; or
(2)
The Village of Livonia agrees to apply to the Federal Emergency Management
Agency (FEMA) for a conditional FIRM and floodway revision, FEMA approval
is received, and the applicant provides all necessary data, analyses
and mapping and reimburses the Village of Livonia for all fees and
other costs in relation to the application. The applicant must also
provide all data, analyses and mapping and reimburse the Village of
Livonia for all costs related to the final map revisions.
A.
Anchoring. New structures and substantial improvement to structures
in areas of special flood hazard shall be anchored to prevent flotation,
collapse or lateral movement during the base flood. This requirement
is in addition to applicable state and local anchoring requirements
for resisting wind forces.
B.
Construction materials and methods.
(1)
New construction and substantial improvements to structures shall
be constructed with materials and utility equipment resistant to flood
damage.
(2)
New construction and substantial improvements to structures shall
be constructed using methods and practices that minimize flood damage.
(3)
Enclosed areas.
(a)
For enclosed areas below the lowest floor of a structure within
Zones A1-A30, AE or AH, and also Zone A if base flood elevation data
are available, new and substantially improved structures shall have
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 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 licensed professional engineer or architect
or meet or exceed the following minimum criteria:
(b)
Openings may be equipped with louvers, valves, screens or other
coverings or devices provided they permit the automatic entry and
exit of floodwaters. Enclosed areas subgrade on all sides are considered
basements and are not permitted.
C.
Utilities.
(1)
Machinery and equipment servicing a building must either be elevated
to or above the base flood level or designed to prevent water from
entering or accumulating within the components during a flood. This
includes heating, ventilating, and air-conditioning equipment, hot-water
heaters, appliances, elevator lift machinery and electrical junction
and circuit breaker boxes. When located below the base flood elevation,
a professional engineer's or architect's certification of
the design is required.
(2)
New and replacement water supply systems shall be designed to minimize
or eliminate infiltration of floodwaters into the system.
(3)
New and replacement sanitary sewage systems shall be designed to
minimize or eliminate infiltration of floodwaters. Sanitary sewer
and storm drainage systems for buildings that have openings below
the base flood elevation shall be provided with automatic backflow
valves or other automatic backflow devices that are installed in each
discharge line passing through a building's exterior wall.
(4)
On-site waste disposal systems shall be located to avoid impairment
to them or contamination from them during flooding.
A.
Elevation. The following standards, in addition to the standards in § 93-15, Subdivision proposals, and § 93-16, Encroachments, and § 93-17, Standards for all structures, apply to structures located in areas of special flood hazard as indicated.
(1)
Within Zones A1-A30, AE and AH, and also Zone A if base flood elevation
data are available, new construction and substantial improvements
shall have the lowest floor (including basement) elevated two feet
or more above the base flood level.
(2)
Within Zone A, when no base flood elevation data are available, new
and substantially improved structures shall have the lowest floor
(including basement) elevated at least three feet above the highest
adjacent grade.
(3)
Within Zone AO, new and substantially improved structures shall have the lowest floor (including basement) elevated above the highest adjacent grade at least as high as the depth number specified in feet on the community's Flood Insurance Rate Map enumerated in § 93-6 (at least two feet if no depth number is specified).
(4)
Within Zones AH and AO, adequate drainage paths are required to guide
floodwaters around and away from proposed structures on slopes.
The following standards apply to new and substantially improved commercial, industrial and other nonresidential structures, in addition to the requirements in § 93-15, Subdivision proposals, and § 93-16, Encroachments, and § 93-17, Standards for all structures.
A.
Within Zones A1-A30, AE and AH, and also Zone A if base flood elevation
data are available, new construction and substantial improvements
of any nonresidential structure, together with attendant utility and
sanitary facilities, shall either:
(1)
Have the lowest floor, including basement or cellar, elevated two
or more feet above the base flood elevation; or
(2)
Be floodproofed so that the structure is watertight below the base
flood level with walls substantially impermeable to the passage of
water. All structural components located below a level two feet above
the base flood level must be capable of resisting hydrostatic and
hydrodynamic loads and the effects of buoyancy.
B.
Within Zone AO, new construction and substantial improvements of
nonresidential structures shall:
(1)
Have the lowest floor (including basement) elevated above the highest
adjacent grade at least as high as the depth number specified in feet
on the community's FIRM (at least two feet if no depth number
is specified); or
C.
If the structure is to be floodproofed, a licensed professional engineer or architect shall develop and/or review structural design, specifications and plans for construction. A floodproofing certificate or other certification shall be provided to the local administrator that certifies the design and methods of construction are in accordance with accepted standards of practice for meeting the provisions of Subsection A(2), including the specific elevation (in relation to mean sea level) to which the structure is to be floodproofed.
D.
Within Zones AH and AO, adequate drainage paths are required to guide
floodwaters around and away from proposed structures on slopes.
E.
Within Zone A, when no base flood elevation data are available, the
lowest floor (including basement) shall be elevated at least three
feet above the highest adjacent grade.
The following standards in addition to the standards in § 93-14, General standards, and § 93-17, Standards for all structures, apply as indicated, in areas of special flood hazard to manufactured homes and to recreational vehicles which are located in areas of special flood hazard.
A.
B.
A manufactured home that is placed or substantially improved in Zones
A1-A30, AE and AH that is on a site either: outside of an existing
manufactured home park or subdivision as herein defined; in a new
manufactured home park or subdivision as herein defined; in an expansion
to an existing manufactured home park or subdivision as herein defined;
or in an existing manufactured home park or subdivision as herein
defined on which a manufactured home has incurred substantial damage
as the result of a flood shall be elevated on a permanent foundation
such that the lowest floor is elevated two feet or more above the
base flood elevation and is securely anchored to an adequately anchored
foundation system to resist flotation, collapse and lateral movement.
Elevation on piers consisting of dry stacked blocks is prohibited.
Methods of anchoring may include, but are not limited to, use of over-the-top
or frame ties to ground anchors.
C.
A manufactured home to be placed or substantially improved in Zone
A1-A30, AE and AH in an existing manufactured home park or subdivision
that is not to be placed on a site on which a manufactured home has
incurred substantial damage shall be:
(2)
Elevated such that 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 the lowest
adjacent grade and are securely anchored to an adequately anchored
foundation system to resist flotation, collapse or lateral movement.
Elevation on piers consisting of dry stacked blocks is prohibited.
D.
Within Zone A, when no base flood elevation data are available, new
and substantially improved manufactured homes shall be elevated such
that 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 the lowest adjacent grade
and are securely anchored to an adequately anchored foundation system
to resist flotation, collapse or lateral movement. Elevation on piers
consisting of dry stacked blocks is prohibited.
