In all areas of special flood hazard, 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 systems;
(6) New
and replacement sanitary sewage systems shall be designed to minimize
or eliminate infiltration of floodwaters into the systems 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.
(1971 Code, sec. 7 1/2-39)
In all areas of special flood hazard where base flood elevation data has been provided as set forth in section
3.12.007, section
3.12.032(8), or subsection (3) of this section, 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 one (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
3.12.033(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 or 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 (2) openings having a total net area of not less
than one (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 one (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.
(1971 Code, sec. 7 1/2-40)
Located within the areas of special flood hazard established in section
3.12.007 are areas designated as shallow flooding. These areas have special flood hazards associated with base flood depths of one (1) to three (3) feet where a clearly defined channel does not exist and 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
shall have the lowest floor (including basement) elevated one (1)
foot (minimum) above the base flood elevation highest adjacent grade,
which shall be at least as high as the depth number specified in feet
on the community’s FIRM (at least two (2) feet if no depth number
is specified). A registered professional engineer, architect, or land
surveyor shall submit a certification to the Town Engineer that the
standard of this section is satisfied.
(2) All
new construction and substantial improvements of nonresidential structures:
(A) Shall have the lowest floor (including basement) elevated at or above
the highest adjacent grade, which shall be at least as high as the
depth number specified in feet on the community’s FIRM (at least
two (2) feet if no depth number is specified); or
(B) Shall 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 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
3.12.033(a)(1), are satisfied.
(4) Require
within zone AH or AO adequate drainage paths around structures on
slopes, to guide floodwaters around and away from proposed structures.
(1971 Code, sec. 7 1/2-41)
Located within areas of special flood hazard established in section
3.12.007 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) 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.
(2) If subsection
(1) above is satisfied, all new construction and substantial improvements shall also comply with all applicable flood hazard reduction provisions of this article.
(3) Under the provisions of 44 CFR, chapter
1, section 65.12, of the National Flood Insurance 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 applies for a conditional FIRM and floodway revision through FEMA.
(1971 Code, sec. 7 1/2-42)