City Hall Building
801 Crawford Street, 4th floor
Portsmouth, VA 23704
Phone (757) 393-8836
Fax (757) 393-5223
International Building Code 2000
Within flood hazard areas as established in Section 1612.3, all
new construction of buildings, structures and portions of
buildings and structures, including substantial improvements and
restoration of substantial damage to buildings and structures,
shall be designed and constructed to resist the effects of flood
hazards and flood loads.
The following words and terms shall, for the purposes of this
section, have the meanings shown herein.
BASE FLOOD. The flood having a 1-percent chance
of being equaled or exceeded in any given year.
BASE FLOOD ELEVATION. The elevation of the base
flood, including wave height, relative to the National Geodetic
Vertical Datum (NGVD), North American Vertical Datum (NAVD) or
other datum specified on the flood insurance rate map (FIRM).
BASEMENT. The portion of a building having its
floor subgrade (below ground level) on all sides.
DESIGN FLOOD. The flood associated with the
greater of the following two areas:
1. Area with a floodplain subject to a
1-percent or greater chance of flooding in any year; or
2. Area designated as a flood hazard area on a community’s flood
hazard map, or otherwise legally designated.
DESIGN FLOOD ELEVATION. The
elevation of the “design flood,” including wave height,
relative to the datum specified on the community’s legally
designated flood hazard map.
DRY FLOODPROOFING. A combination of design
modifications that result in a building or structure, including
the attendant utility and sanitary facilities, being watertight
with walls substantially impermeable to the passage of water and
with structural components having the capacity to resist loads
as identified in ASCE 7.
EXISTING CONSTRUCTION. Any buildings and
structures for which the “start of construction” commenced
before the effective date of the community’s first floodplain
management code, ordinance or standard. “Existing construction”
may also be referred to as “existing structures.”
EXISTING STRUCTURE. See “Existing
FLOOD or FLOODING. A general and temporary
condition of partial or complete inundation of normally dry land
1. The overflow of inland or tidal waters.
2. The unusual and rapid accumulation or runoff of surface
waters from any source.
FLOOD DAMAGE-RESISTANT MATERIALS.
Any construction material capable of withstanding direct and
prolonged contact with floodwaters without sustaining any
damage that requires more than cosmetic repair.
FLOOD HAZARD AREA. The greater of the following
1. The area within a floodplain subject to a
1-percent or greater chance of flooding in any year.
2. The area designated as a flood hazard area on a community’s
flood hazard map, or otherwise legally designated.
FLOOD HAZARD AREA SUBJECT TO HIGH
VELOCITY WAVE ACTION. Area within the flood hazard
area that is subject to high velocity wave action, and shown on
a Flood Insurance Rate Map or other flood hazard map as Zone V,
VO, VE, or V 1-30.
FLOOD INSURANCE RATE MAP (FIRM). An official
map of a community on which the Federal Emergency Management
Agency has delineated both the special flood hazard areas and
the risk premium zones applicable to the community.
FLOOD INSURANCE STUDY. The official report
provided by the Federal Emergency Management Agency containing
the Flood Insurance Rate Map, the Flood Boundary and Floodway
Map (FBFM), the water surface elevation of the base flood and
supporting technical data.
FLOODWAY. The channel of the river, creek, or
other watercourse and the adjacent land areas that must be
reserved in order to discharge the base flood without
cumulatively increasing the water surface elevation more than a
LOWEST FLOOR. The floor of the lowest enclosed
area, including basement, but excluding any unfinished or
flood-resistant enclosure, usable solely for vehicle parking,
building access, or limited storage provided that such enclosure
is not built so as to render the structure in violation of this
SPECIAL FLOOD HAZARD AREA. The land area
subject to flood hazards and shown on a Flood Insurance Rate Map
or other flood hazard map as Zone A, AE, A1-30, A99, AR, AO, AH,
V, VO, VE, or V1-30.
START OF CONSTRUCTION. The
date of permit issuance for new construction and substantial
improvements to existing structures, provided the actual start
of construction, repair, reconstruction, rehabilitation,
addition placement, or other improvement is within 180 days
after the date of issuance. The actual start of construction
means the first placement of permanent construction of a
building (including a manufactured home) on a site, such as the
pouring of a slab or footings, installation of pilings or
construction of columns.
Permanent construction does not include land preparation (such
as clearing, excavation, grading, or filling), or the
installation of streets or walkways, or excavation for a
basement, footings, piers or foundations, or the erection of
temporary forms, or the installation of accessory buildings such
as garages or sheds not occupied as dwelling units or not part
of the main building. For a substantial improvement, the actual
“start of construction” means the first alteration of any wall,
ceiling, floor, or other structural part of a building, whether
or not that alteration affects the external dimensions of the
SUBSTANTIAL DAMAGE. Damage of any origin
sustained by a structure whereby the cost of restoring the
structure to its before damaged condition would equal or exceed
50 percent of the market value of the structure before the
SUBSTANTIAL IMPROVEMENT. Any
repair reconstruction, rehabilitation, addition, or improvement
of a building or structure, the cost of which equals or exceeds
50 percent of the market value of the structure before the
improvement or repair is started. If the structure has sustained
substantial damage, any repairs are considered substantial
improvement regardless of the actual repair work performed. The
term does not, however, include either:
1. Any project for improvement of a building required to correct
existing health, sanitary or safety code violations identified
by the building official and that are the minimum necessary to
assure safe living conditions.
2.Any alteration of a historic structure provided that the
alteration will not preclude the structure’s continued
designation as a historic structure.
16123 Establishment of flood hazard areas.
To establish flood hazard areas, the governing body shall adopt
a flood hazard map and supporting data. The flood hazard map
shall include, at a minimum, areas of special flood hazard as
identified by the Federal Emergency Management Agency in an
engineering report entitled “The Flood Insurance Study for
[INSERT NAME OF JURSDICTION]’ dated [INSERT DATE OF ISSUANCE],
as amend or revised with the accompanying Flood Insurance Rate M
(FIRM) and Flood Boundary and Floodway Map (FBFM) a related
supporting data along with any revisions thereto. T adopted
flood hazard map and supporting data are herd adopted by
reference and declared to be part of this section.
1612.4 Design and construction.
The design and construction of buildings and structures located
in flood hazard areas, including flood hazard areas subject to
high velocity wave action, should be designed and constructed in
accordance with ASCE 24.
1612.5 Flood hazard certificates.
The following certifications shall be submitted to the building
1. For construction in flood hazard areas not
subject high-velocity wave action:
1.1. As part of the lowest floor elevation
inspection required in Section 109.3.3, certification of the
elevation of the lowest floor, including basement
1.2. For fully enclosed areas below the design flood elevation
where provisions to allow for the automatic entry and exit of
floodwaters do not m~ the minimum requirements in Section 2.6.1
ASCE 24, certification by a registered design, professional that
the design will provide I equalization of hydrostatic flood
forces in accordance with Section 18.104.22.168, ASCE 24.
1.3. For dry flood-proofed nonresidential building certification
by a registered design professional that the dry flood-proofing
is designed in accordance with ASCE 24.
2. For construction in flood hazard areas
subject to high velocity wave action:
2.1. As part of the lowest floor elevation
inspection required in Section 109.3.3, a certification of
elevation of the lowest horizontal structure member.
2.2. A certificate prepared by a registered design professional
that the building is designed in acc dance with ASCE 24,
including that the pile column foundation and building or
structure to attached thereto is designed to be anchored to
resist flotation, collapse and lateral movement d to the effects
of wind and flood loads acting simultaneously on all building
components, a other load requirements of Chapter 16.
2.3. For breakaway walls designed to resist a nominal load of
less than 10 pounds per square foot (0. kN/m2) or more than 20
pounds per square foot (0.96 kN/m2), a certificate prepared by a
registered design professional that the breakaway wall is
designed in accordance with ASCE 24.