The legislature of the state has, in the Flood Control Insurance
Act, Texas Water Code, section 16.315, delegated the responsibility
to local governmental units to adopt regulations designed to minimize
flood losses. This article is adopted pursuant to that authority.
(Ordinance 1162, sec. 1 (3.1601),
adopted 9/10/19)
(a) The
flood hazard areas of the city are subject to periodic inundation,
which results in loss of life and property, health and safety hazards,
disruption of commerce and governmental services, and extraordinary
public expenditures for flood protection and relief, all of which
adversely affect the public health, safety and general welfare.
(b) These
flood losses are created by the cumulative effect of obstructions
in floodplains which cause an increase in flood heights and velocities,
and by the occupancy of flood hazard areas by uses vulnerable to floods
and hazardous to other lands because they are inadequately elevated,
floodproofed or otherwise protected from flood damage.
(Ordinance 1162, sec. 1 (3.1602),
adopted 9/10/19)
It is the purpose of this article to promote the public health,
safety and general welfare and to minimize public and private losses
due to flood conditions in specific areas by provisions designed to:
(1) Protect
human life and health;
(2) Minimize
expenditure of public money for costly flood control projects;
(3) Minimize
the need for rescue and relief efforts associated with flooding and
generally undertaken at the expense of the general public;
(4) Minimize
prolonged business interruptions;
(5) Minimize
damage to public facilities and utilities such as water and gas mains,
electric, telephone and sewer lines, streets and bridges located in
floodplains;
(6) Help
maintain a stable tax base by providing for the sound use and development
of floodprone areas in such a manner as to minimize future flood blight
areas; and
(7) Insure
that potential buyers are notified that property is in a flood area.
(Ordinance 1162, sec. 1 (3.1603),
adopted 9/10/19)
In order to accomplish its purposes, this article uses the following
methods:
(1) Restrict
or prohibit uses that are dangerous to health, safety or property
in times of flood, or cause excessive increases in flood heights or
velocities;
(2) Require
that uses vulnerable to floods, including facilities which serve such
uses, be protected against flood damage at the time of initial construction;
(3) Control
the alteration of natural floodplains, stream channels, and natural
protective barriers, which are involved in the accommodation of floodwaters;
(4) Control
filling, grading, dredging and other development which may increase
flood damage;
(5) Prevent
or regulate the construction of flood barriers which will unnaturally
divert floodwaters or which may increase flood hazards to other lands.
(Ordinance 1162, sec. 1 (3.1604),
adopted 9/10/19)
Unless specifically defined below, words or phrases used in
this article shall be interpreted to give them the meaning they have
in common usage and to give this article its most reasonable application.
Alluvial fan flooding
means flooding occurring on the surface of an alluvial fan
or similar landform which originates at the apex and is characterized
by high-velocity flows; active processes of erosion, sediment transport,
and deposition; and unpredictable flow paths.
Apex
means a point on an alluvial fan or similar landform below
which the flow path of the major stream that formed the fan becomes
unpredictable and alluvial fan flooding can occur.
Appurtenant structure
means a structure which is on the same parcel of property
as the principal structure to be insured and the use of which is incidental
to the use of the principal structure.
Area of shallow flooding
means a designated AO, AH, AR/AO, AR/AH, or VO zone on a
community’s flood insurance rate map (FIRM) with a 1 percent
or greater annual chance of flooding to an average depth of 1 to 3
feet where a clearly defined channel does not exist, where the path
of flooding is unpredictable and where velocity flow may be evident.
Such flooding is characterized by ponding or sheet flow.
Area of special flood hazard
is the land in the floodplain within a community subject
to a 1 percent or greater chance of flooding in any given year. The
area may be designated as zone A on the flood hazard boundary map
(FHBM). After detailed rate-making has been completed in preparation
for publication of the FIRM, zone A usually is refined into zones
A, AO, AH, A1-30, AE, A99, AR, AR/A1-30, AR/AE, AR/AO, AR/AH, AR/A,
VO, V1-30, VE or V.
Base flood
means the flood having a 1 percent chance of being equaled
or exceeded in any given year.
Base flood elevation (BFE)
means the elevation shown on the flood insurance rate map
(FIRM) and found in the accompanying flood insurance study (FIS) for
zones A, AE, AH, A1-A30, AR, V1-V30, or VE that indicates the water
surface elevation resulting from the flood that has a 1% chance of
equaling or exceeding that level in any given year, also called the
base flood.
Basement
means any area of the building having its floor subgrade
(below ground level) on all sides.
Breakaway wall
means a wall that is not part of the structural support
of the building and is intended through its design and construction
to collapse under specific lateral loading forces, without causing
damage to the elevated portion of the building or supporting foundation
system.
Critical feature
means an integral and readily identifiable part of a flood
protection system, without which the flood protection provided by
the entire system would be compromised.
Development
means any man-made change to improved and unimproved real
estate, including but not limited to buildings or other structures,
mining, dredging, filling, grading, paving, excavation or drilling
operations or storage of equipment or materials.
Elevated building
means, for insurance purposes, a non-basement building,
which has its lowest elevated floor raised above ground level by foundation
walls, shear walls, posts, piers, pilings, or columns.
Existing construction
means, for the purposes of determining rates, structures
for which the “start of construction” commenced before
the effective date of the FIRM or before January 1, 1975, for FIRMs
effective before that date. “Existing construction” may
also be referred to as “existing structures.”
Existing manufactured home park or subdivision
means a manufactured home park or subdivision for which
the construction of facilities for servicing the lots on which the
manufactured homes are to be affixed (including, at a minimum, the
installation of utilities, the construction of streets, and either
final site grading or the pouring of concrete pads) is completed before
the effective date of the floodplain management regulations adopted
by a community.
Expansion to an existing manufactured home park or subdivision
means the preparation of additional sites by the construction
of facilities for servicing the lots on which the manufactured homes
are to be affixed (including the installation of utilities, the construction
of streets, and either final site grading or the pouring of concrete
pads).
Flood or flooding
means a general and temporary condition of partial or complete
inundation of normally dry land areas from:
(1)
The overflow of inland or tidal waters.
(2)
The unusual and rapid accumulation or runoff of surface waters
from any source.
Flood elevation study
means an examination, evaluation and determination of flood
hazards and, if appropriate, corresponding water surface elevations,
or an examination, evaluation and determination of mudslide (i.e.,
mudflow) and/or flood-related erosion hazards.
Flood insurance rate map (FIRM)
means 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.
Floodplain management
means the operation of an overall program of corrective
and preventive measures for reducing flood damage, including but not
limited to emergency preparedness plans, flood control works and floodplain
management regulations.
Floodplain management regulations
means zoning ordinances, subdivision regulations, building
codes, health regulations, special purpose ordinances (such as a floodplain
ordinance, grading ordinance and erosion control ordinance) and other
applications of police power. The term describes such state or local
regulations, in any combination thereof, which provide standards for
the purpose of flood damage prevention and reduction.
Floodproofing
means any combination of structural and non-structural additions,
changes, or adjustments to structures which reduce or eliminate flood
damage to real estate or improved real property, water and sanitary
facilities, structures and their contents.
Flood protection system
means those physical structural works for which funds have
been authorized, appropriated, and expended and which have been constructed
specifically to modify flooding in order to reduce the extent of the
area within a community subject to a “special flood hazard”
and the extent of the depths of associated flooding. Such a system
typically includes hurricane tidal barriers, dams, reservoirs, levees
or dikes. These specialized flood-modifying works are those constructed
in conformance with sound engineering standards.
Functionally dependent use
means a use which cannot perform its intended purpose unless
it is located or carried out in close proximity to water. The term
includes only docking facilities, port facilities that are necessary
for the loading and unloading of cargo or passengers, and ship building
and ship repair facilities, but does not include long-term storage
or related manufacturing facilities.
Highest adjacent grade
means the highest natural elevation of the ground surface
prior to construction next to the proposed walls of a structure.
Historic structure
means any structure that is:
(1)
Listed individually in the National Register of Historic Places
(a listing maintained by the Department of the Interior) or preliminarily
determined by the Secretary of the Interior as meeting the requirements
for individual listing on the National Register;
(2)
Certified or preliminarily determined by the Secretary of the
Interior as contributing to the historical significance of a registered
historic district or a district preliminarily determined by the Secretary
to qualify as a registered historic district;
(3)
Individually listed on a state inventory of historic places
in states with historic preservation programs which have been approved
by the Secretary of the Interior; or
(4)
Individually listed on a local inventory of historic places
in communities with historic preservation programs that have been
certified either:
(A)
By an approved state program as determined by the Secretary
of the Interior; or
(B)
Directly by the Secretary of the Interior in states without
approved programs.
Levee
means a man-made structure, usually an earthen embankment,
designed and constructed in accordance with sound engineering practices
to contain, control, or divert the flow of water so as to provide
protection from temporary flooding.
Levee system
means a flood protection system which consists of a levee,
or levees, and associated structures, such as closure and drainage
devices, which are constructed and operated in accordance with sound
engineering practices.
Lowest floor
means the lowest floor of the lowest enclosed area (including
basement). An unfinished or flood-resistant enclosure, usable solely
for parking of vehicles, building access or storage in an area other
than a basement area is not considered a building’s lowest floor,
provided that such enclosure is not built so as to render the structure
in violation of the applicable non-elevation design requirement of
section 60.3 of the National Flood Insurance Program regulations.
Manufactured home
means a structure transportable in one or more sections,
which is built on a permanent chassis and is designed for use with
or without a permanent foundation when connected to the required utilities.
The term “manufactured home” does not include a “recreational
vehicle.”
Mean sea level
means, for purposes of the National Flood Insurance Program,
the North American Vertical Datum (NAVD) of 1988 or other datum, to
which base flood elevations shown on a community’s flood insurance
rate map are referenced.
New construction
means, for the purpose of determining insurance rates, structures
for which the “start of construction” commenced on or
after the effective date of an initial FIRM or after December 31,
1974, whichever is later, and includes any subsequent improvements
to such structures. For floodplain management purposes, “new
construction” means structures for which the “start of
construction” commenced on or after the effective date of a
floodplain management regulation adopted by a community and includes
any subsequent improvements to such structures.
New manufactured home park or subdivision
means a manufactured home park or subdivision for which
the construction of facilities for servicing the lots on which the
manufactured homes are to be affixed (including, at a minimum, the
installation of utilities, the construction of streets, and either
final site grading or the pouring of concrete pads) is completed on
or after the effective date of floodplain management regulations adopted
by a community.
Recreational vehicle
means a vehicle which is (i) built on a single chassis;
(ii) 400 square feet or less when measured at the largest horizontal
projections; (iii) designed to be self-propelled or permanently towable
by a light duty truck; and (iv) designed primarily not for use as
a permanent dwelling but as temporary living quarters for recreational,
camping, travel, or seasonal use.
Regulatory floodway
means the channel of a river 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 designated height.
Riverine
means relating to, formed by, or resembling a river (including
tributaries), stream, brook, etc.
Start of construction
(for other than new construction or substantial improvements
under the Coastal Barrier Resources Act (Pub. L. 97-348)) includes
substantial improvement and means the date the building permit was
issued, provided the actual start of construction, repair, reconstruction,
rehabilitation, addition, placement, or other improvement was within
180 days of the permit date. The actual start means either the first
placement of permanent construction of a structure on a site, such
as the pouring of slab or footings, the installation of piles, the
construction of columns, or any work beyond the stage of excavation;
or the placement of a manufactured home on a foundation. Permanent
construction does not include land preparation, such as clearing,
grading and filling; nor does it include the installation of streets
and/or walkways; nor does it include excavation for basement, footings,
piers or foundations or the erection of temporary forms; nor does
it include the installation on the property of accessory buildings,
such as garages or sheds not occupied as dwelling units or not part
of the main structure. 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 building.
Structure
means, for floodplain management purposes, a walled and
roofed building, including a gas or liquid storage tank, that is principally
above ground, as well as a manufactured home.
Substantial damage
means 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 damage occurred.
Substantial improvement
means any reconstruction, rehabilitation, addition, or other
improvement of a structure, the cost of which equals or exceeds 50
percent of the market value of the structure before “start of
construction” of the improvement. This term includes structures
which have incurred “substantial damage,” regardless of
the actual repair work performed. The term does not, however, include
either:
(1)
Any project for improvement of a structure to correct existing
violations of state or local health, sanitary, or safety code specifications
which have been identified by the local code enforcement official
and which are the minimum necessary to assure safe living conditions;
or
(2)
Any alteration of a “historic structure,” provided
that the alteration will not preclude the structure’s continued
designation as a “historic structure.”
Variance
means a grant of relief by a community from the terms of
a floodplain management regulation. (For full requirements see section
60.6 of the National Flood Insurance Program regulations.)
Violation
means the failure of a structure or other development to
be fully compliant with the community’s floodplain management
regulations. A structure or other development without the elevation
certificate, other certifications, or other evidence of compliance
required in section 60.3(b)(5), (c)(4), (c)(10), (d)(3), (e)(2), (e)(4),
or (e)(5) [of the National Flood Insurance Program regulations] is
presumed to be in violation until such time as that documentation
is provided.
Water surface elevation
means the height, in relation to the North American Vertical
Datum (NAVD) of 1988 (or other datum, where specified), of floods
of various magnitudes and frequencies in the floodplains of coastal
or riverine areas.
(Ordinance 1162, sec. 1 (3.1605),
adopted 9/10/19)
This article shall apply to all areas of special flood hazard
within the jurisdiction of the city.
(Ordinance 1162, sec. 1 (3.1606),
adopted 9/10/19)
The areas of special flood hazard identified by the Federal
Emergency Management Agency in the current scientific and engineering
report entitled “The Flood Insurance Study (FIS) for Tarrant
County, Texas and Incorporated Areas,” dated March 21, 2019,
with accompanying flood insurance rate maps dated March 21, 2019,
and any revisions thereto are hereby adopted by reference and declared
to be a part of this article.
(Ordinance 1162, sec. 1 (3.1607),
adopted 9/10/19)
A floodplain development permit shall be required to ensure
conformance with the provisions of this article.
(Ordinance 1162, sec. 1 (3.1608),
adopted 9/10/19)
No structure or land shall hereafter be located, altered, or
have its use changed without full compliance with the terms of this
article and other applicable regulations.
(Ordinance 1162, sec. 1 (3.1609),
adopted 9/10/19)
This article is not intended to repeal, abrogate, or impair
any existing easements, covenants, or deed restrictions. However,
where this article and another ordinance, easement, covenant, or deed
restriction conflict or overlap, whichever imposes the more stringent
restrictions shall prevail.
(Ordinance 1162, sec. 1 (3.1610),
adopted 9/10/19)
In the interpretation and application of this article, all provisions
shall be:
(1) Considered
as minimum requirements;
(2) Liberally
construed in favor of the governing body; and
(3) Deemed
neither to limit nor repeal any other powers granted under state statutes.
(Ordinance 1162, sec. 1 (3.1611),
adopted 9/10/19)
The degree of flood protection required by this article is considered
reasonable for regulatory purposes and is based on scientific and
engineering considerations. On rare occasions greater floods can and
will occur and flood heights may be increased by man-made or natural
causes. This article does not imply that land outside the areas of
special flood hazards or uses permitted within such areas will be
free from flooding or flood damages. This article shall not create
liability on the part of the community or any official or employee
thereof for any flood damages that result from reliance on this article
or any administrative decision lawfully made hereunder.
(Ordinance 1162, sec. 1 (3.1612),
adopted 9/10/19)
The city manager or his designee is hereby appointed the floodplain
administrator to administer and implement the provisions of this article
and other appropriate sections of 44 CFR (Emergency Management and
Assistance, National Flood Insurance Program Regulations) pertaining
to floodplain management.
(Ordinance 1162, sec. 1 (3.1613),
adopted 9/10/19)
Duties and responsibilities of the floodplain administrator
shall include, but not be limited to, the following:
(1) Maintain
and hold open for public inspection all records pertaining to the
provisions of this article.
(2) Review
permit applications to determine whether to ensure that the proposed
building site project, including the placement of manufactured homes,
will be reasonably safe from flooding.
(3) Review,
approve or deny all applications for development permits required
by adoption of this article.
(4) Review
permits for proposed development to assure that all necessary permits
have been obtained from those federal, state or local governmental
agencies (including section 404 of the Federal Water Pollution Control
Act Amendments of 1972, 33 U.S.C. 1334) from which prior approval
is required.
(5) Where
interpretation is needed as to the exact location of the boundaries
of the areas of special flood hazards (for example, where there appears
to be a conflict between a mapped boundary and actual field conditions),
the floodplain administrator shall make the necessary interpretation.
(6) Notify,
in riverine situations, adjacent communities and the state coordinating
agency, which is the state water development board (TWDB), and also
the state commission on environmental quality (TCEQ), prior to any
alteration or relocation of a watercourse, and submit evidence of
such notification to the Federal Emergency Management Agency.
(7) Assure
that the flood-carrying capacity within the altered or relocated portion
of any watercourse is maintained.
(8) When base flood elevation data has not been provided in accordance with section
3.09.007, the floodplain administrator shall obtain, review and reasonably utilize any base flood elevation data and floodway data available from a federal, state or other source, in order to administer the provisions of this article.
(9) When
a regulatory floodway has not been designated, the floodplain administrator
must require that no new construction, substantial improvements, or
other development (including fill) shall be permitted within zones
A1-30 and AE on the community’s FIRM, unless it is demonstrated
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 point within the community.
(10) Under the provisions of 44 CFR chapter
1, section 65.12, of the National Flood Insurance Program regulations, a community may approve certain development in zones A1-30, AE, [and] AH, on the community’s FIRM which increases the water surface elevation of the base flood by more than 1 foot, provided that the community first completes all of the provisions required by section 65.12.
(Ordinance 1162, sec. 1 (3.1614),
adopted 9/10/19)
(a) Application
for a floodplain development permit shall be presented to the floodplain
administrator on forms furnished by him/her and may include, but not
be limited to, plans in duplicate drawn to scale showing the location,
dimensions, and elevation of proposed landscape alterations, existing
and proposed structures, including the placement of manufactured homes,
and the location of the foregoing in relation to areas of special
flood hazard. Additionally, the following information is required:
(1) Elevation (in relation to mean sea level) of the lowest floor (including
basement) of all new and substantially improved structures;
(2) Elevation in relation to mean sea level to which any nonresidential
structure shall be floodproofed;
(3) A certificate from a registered professional engineer or architect that the nonresidential floodproofed structure shall meet the floodproofing criteria of section
3.09.018(2);
(4) Description of the extent to which any watercourse or natural drainage
will be altered or relocated as a result of proposed development;
(5) Maintain a record of all such information in accordance with section
3.09.014(1);
(b) Approval
or denial of a floodplain development permit by the floodplain administrator
shall be based on all of the provisions of this article and the following
relevant factors:
(1) The danger to life and property due to flooding or erosion damage;
(2) The susceptibility of the proposed facility and its contents to flood
damage and the effect of such damage on the individual owner;
(3) The danger that materials may be swept onto other lands to the injury
of others;
(4) The compatibility of the proposed use with existing and anticipated
development;
(5) The safety of access to the property in times of flood for ordinary
and emergency vehicles;
(6) The costs of providing governmental services during and after flood
conditions including maintenance and repair of streets and bridges,
and public utilities and facilities such as sewer, gas, electrical
and water systems;
(7) The expected heights, velocity, duration, rate of rise and sediment
transport of the floodwaters and the effects of wave action, if applicable,
expected at the site;
(8) The necessity to the facility of a waterfront location, where applicable;
(9) The availability of alternative locations, not subject to flooding
or erosion damage, for the proposed use.
(Ordinance 1162, sec. 1 (3.1615),
adopted 9/10/19)
(a) The
board of adjustment shall hear and render judgment on requests for
variances from the requirements of this article.
(b) The
board of adjustment shall hear and render judgment on an appeal only
when it is alleged there is an error in any requirement, decision,
or determination made by the floodplain administrator in the enforcement
or administration of this article.
(c) Any
person or persons aggrieved by the decision of the board of adjustment
may appeal such decision in the courts of competent jurisdiction.
(d) The
floodplain administrator shall maintain a record of all actions involving
an appeal and shall report variances to the Federal Emergency Management
Agency upon request.
(e) Variances
may be issued for the reconstruction, rehabilitation or restoration
of structures listed on the National Register of Historic Places or
the state inventory of historic places, without regard to the procedures
set forth in the remainder of this article.
(f) Variances may be issued for new construction and substantial improvements to be erected on a lot of 1/2 acre or less in size contiguous to and surrounded by lots with existing structures constructed below the base flood level, providing the relevant factors in section
3.09.015 of this article have been fully considered. As the lot size increases beyond the 1/2 acre, the technical justification required for issuing the variance increases.
(g) Upon
consideration of the factors noted above and the intent of this article,
the board of adjustment may attach such conditions to the granting
of variances as it deems necessary to further the purpose and objectives
of this article.
(h) Variances
shall not be issued within any designated floodway if any increase
in flood levels during the base flood discharge would result.
(i) Variances
may be issued for the repair or rehabilitation of historic structures
upon a determination that the proposed repair or rehabilitation will
not preclude the structure’s continued designation as a historic
structure and the variance is the minimum necessary to preserve the
historic character and design of the structure.
(j) Prerequisites
for granting variances:
(1) Variances shall only be issued upon a determination that the variance
is the minimum necessary, considering the flood hazard, to afford
relief.
(2) Variances shall only be issued upon: (i) showing a good and sufficient
cause; (ii) a determination that failure to grant the variance would
result in exceptional hardship to the applicant, and (iii) a determination
that the granting of a variance will not result in increased flood
heights, additional threats to public safety, or extraordinary public
expense, create nuisances, cause fraud on or victimization of the
public, or conflict with existing local laws or ordinances.
(3) Any applicant to which a variance is granted shall be given written
notice that the structure will be permitted to be built with the lowest
floor elevation below the base flood elevation, and that the cost
of flood insurance will be commensurate with the increased risk resulting
from the reduced lowest floor elevation.
(k) Variances
may be issued for new construction and substantial improvements and
for other development necessary for the conduct of a functionally
dependent use provided that:
(1) The criteria outlined in subsections
(a) through
(i) of this section are met; and
(2) The structure or other development is protected by methods that minimize
flood damages during the base flood and create no additional threats
to public safety.
(Ordinance 1162, sec. 1 (3.1616),
adopted 9/10/19; Ordinance adopting
2021 Code)
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 1162, sec. 1 (3.1617),
adopted 9/10/19)
In all areas of special flood hazards where base flood elevation data has been provided as set forth in section
3.09.007, section
3.09.014(8), or section
3.09.019(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 two (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
3.09.015(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 two (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 FHBM or FIRM shall be installed using methods
and practices which 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 two (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 being placed or substantially improved
on sites in an existing manufactured home park or subdivision within
zones A1-30, AH and AE on the community’s FIRM that are not
subject to the provisions of subsection (4)(A) or (4)(B) of this section
be elevated so that either:
(i) The lowest floor of the manufactured home is at two (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.
(5) Recreational vehicles.
Require that recreational vehicles placed on sites within zones A1-30, AH, and AE on the community’s FIRM either (i) be on the site for fewer than 180 consecutive days, or (ii) be fully licensed and ready for highway use, or (iii) meet the permit requirements of section
3.09.015(a) and the elevation and anchoring requirements for “manufactured homes” in subsection
(4) of this section. A recreational vehicle is ready for highway use if it is on its wheels or jacking system, is attached to the site only by quick-disconnect type utilities and security devices, and has no permanently attached additions.
(Ordinance 1162, sec. 1 (3.1618),
adopted 9/10/19)
(a) All subdivision proposals including the placement of manufactured home parks and subdivisions shall be consistent with sections
3.09.002,
3.09.003, and
3.09.004 of this article.
(b) All proposals for the development of subdivisions including the placement of manufactured home parks and subdivisions shall meet the floodplain development permit requirements of section
3.09.008 and section
3.09.015 and the provisions of sections
3.09.017,
3.09.018,
3.09.019,
3.09.020, and
3.09.021 of this article.
(c) Base flood elevation data shall be generated with [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
3.09.007 or section
3.09.014(8) 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 1162, sec. 1 (3.1619),
adopted 9/10/19)
Located within the areas of special flood hazard established in section
3.09.007 are areas designated as shallow flooding. These areas have special flood hazards associated with flood depths of 1 to 3 feet where a clearly defined channel does not exist, 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
have the lowest floor (including basement) elevated to two (2) feet
above the base flood elevation or the highest adjacent grade at least
as high as the depth number specified in feet on the FIRM (at least
2 feet if no depth number is specified).
(2) All
new construction and substantial improvements of nonresidential structures:
(A) Have the lowest floor (including basement) elevated to two (2) feet
above the base flood elevation or the highest adjacent grade at least
as high as the depth number specified in feet on the community’s
FIRM (at least 2 feet if no depth number is specified); or
(B) Together with attendant utility and sanitary facilities be designed
so that below the base specified flood depth in an AO zone, or below
the base flood elevation in an AH zone, 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
3.09.015, are satisfied.
(4) Require
within zones AH or AO adequate drainage paths around structures on
slopes, to guide floodwaters around and away from proposed structures.
(Ordinance 1162, sec. 1 (3.1620),
adopted 9/10/19)
Located within areas of special flood hazard established in section
3.09.007 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 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 Program 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 completes all of the provisions required by section 65.12.
(Ordinance 1162, sec. 1 (3.1621),
adopted 9/10/19)