In all areas of special flood hazards the following standards
are required:
A. Anchoring.
1. All
new construction and substantial improvements shall be 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 manufactured homes shall meet the anchoring standards of Section
15.28.200.
B. Construction
Materials and Methods. All new construction and substantial improvement
shall be constructed:
1. With
flood resistant materials as specified in FEMA Technical Bulletin
TB 2-93, and utility equipment resistant to flood damage;
2. Using
methods and practices that minimize flood damage;
3. 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; and if
4. Within
zones AH or AO, so that there are adequate drainage paths around structures
on slopes to guide floodwaters around and away from proposed structures.
C. Elevation and Floodproofing. (See Section
15.28.050 definitions for basement, lowest floor, new construction, substantial damage and substantial improvement.)
1. Residential
construction, new or substantial improvement, shall have the lowest
floor, including basement:
a. In an AO zone, elevated above the highest adjacent grade to a height
equal to or exceeding the depth number specified in feet on the FIRM,
or elevated at least two feet above the highest adjacent grade if
no depth number is specified. (The state of California recommends
that in AO zones without velocity the lowest floor be elevated above
the highest adjacent grade to a height exceeding the depth number
specified in feet on the FIRM by at least two feet, or elevated at
least four feet above the highest adjacent grade if no depth number
is specified.)
b. In an A zone, elevated to or above the base flood elevation; such base flood elevation shall be determined by one of the methods in Section
15.28.150(B). (The state of California recommends the lowest floor be elevated at least two feet above the base flood elevation, as determined by the community.)
c. In all other zones, elevated to or above the base flood elevation.
(The state of California recommends the lowest floor be elevated at
least two feet above the base flood elevation.)
Upon the completion of the structure, the elevation of the lowest
floor including basement shall be certified by a registered professional
engineer or surveyor, and verified by the community building inspector
to be properly elevated. Such certification and verification shall
be provided to the floodplain administrator.
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2. Nonresidential
construction, new or substantial improvement, shall either be elevated
to conform with Section 15.28.170(C)(l) or together with attendant
utility and sanitary facilities:
a. Be floodproofed below the elevation recommended under Section 15.28.170(C)(l)
so that the structure is watertight with walls substantially impermeable
to the passage of water;
b. Have structural components capable of resisting hydrostatic and hydrodynamic
loads and effects of buoyancy; and
c. Be certified by a registered professional engineer or architect that
the standards of this section are satisfied. Such certification shall
be provided to the floodplain administrator.
3. All
new construction and substantial improvement with fully enclosed areas
below the lowest floor (excluding basements) that are usable solely
for parking of vehicles, building access or storage, 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 floodwater.
Designs for meeting this requirement shall follow the guidelines
in FEMA Technical Bulletins TB 1-93 and TB 7-93, and must exceed the
following minimum criteria:
a. Have a minimum of two openings having a total net area of not less
than one square inch for every square foot of enclosed area subject
to flooding. The bottom of all openings shall be no higher than one
foot above grade. Openings may be equipped with screens, louvers,
valves or other coverings or devices provided that they permit the
automatic entry and exit of floodwater; or
b. Be certified by a registered professional engineer or architect.
4. Manufactured homes shall also meet the standards in Section
15.28.200.
(Ord. 388, 1987; Ord. 770, 2001)
A. All
new and replacement water supply and sanitary sewage systems shall
be designed to minimize or eliminate:
1. Infiltration
of floodwaters into the systems, and
2. Discharge
from the systems into floodwaters.
B. On-site
waste disposal systems shall be located to avoid impairment to them,
or contamination from them during flooding.
(Ord. 388, 1987; Ord. 770, 2001)
A. All
preliminary subdivision proposals shall identify the special flood
hazard area and the elevation of the base flood.
B. All
subdivision plans will provide the elevation of proposed structure(s)
and pad(s). If the site is filled above the base flood elevation,
the lowest floor and pad elevations shall be certified by a registered
professional engineer or surveyor and provided to the floodplain administrator.
C. All
subdivision proposals shall be consistent with the need to minimize
flood damage.
D. All
subdivision proposals shall have public utilities and facilities such
as sewer, gas, electrical and water systems located and constructed
to minimize flood damage.
E. All
subdivisions shall provide adequate drainage to reduce exposure to
flood hazards.
(Ord. 388, 1987; Ord. 770, 2001)
A. All
manufactured homes that are placed or substantially improved, within
zones Al-30, AH, and AE on the community's flood insurance rate map,
on sites located:
1. Outside
of a manufactured home park or subdivision,
2. In
a new manufactured home park or subdivision,
3. In
an expansion to an existing manufactured home park or subdivision,
or
4. In
an existing manufactured home park or subdivision on a site upon 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 of the manufactured home is elevated to or above the
base flood elevation (the state of California recommends at least
two feet above the base flood elevation) and be securely fastened
to an adequately anchored foundation system to resist flotation, collapse,
and lateral movement.
B. All manufactured homes that are placed or substantially improved on sites located within zones Vl-30, V, and VE on the community's flood insurance rate map will meet the requirements of Section
15.28.200(A).
C. All
manufactured homes to be placed or substantially improved on sites
in an existing manufactured home park or subdivision within zones
Al-30, AH, AE, V1-30, V, and VE on the community's flood insurance
rate map that are not subject to the provisions of paragraph 15.28.200(A)
will be securely fastened to an adequately anchored foundation system
to resist flotation, collapse, and lateral movement, and be elevated
so that either the:
1. Lowest
floor of the manufactured home is at or above the base flood elevation
(the state of California recommends at least two feet above the base
flood elevation), or
2. Manufactured
home chassis is supported by reinforced piers or other foundation
elements of at least equivalent strength that are no less than thirty-six
inches in height above grade.
Upon the completion of the structure, the elevation of the lowest
floor including basement shall be certified by a registered professional
engineer or surveyor, and verified by the community building inspector
to be properly elevated. Such certification and verification shall
be provided to the floodplain administrator.
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(Ord. 388, 1987; Ord. 770, 2001)
Located within areas of special flood hazard established in Section
15.28.070 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 apply:
A. Prohibit
encroachments, including fill, new construction, substantial improvement,
and other new development unless certification by a registered professional
engineer is provided demonstrating that encroachments shall not result
in any increase in (the base) flood elevation during the occurrence
of the base flood discharge.
B. If Section
15.28.220(A) is satisfied, all new construction, substantial improvement, and other proposed new development shall comply with all other applicable flood hazard reduction provisions of Article IV.
(Ord. 388, 1987; Ord. 770, 2001)