HomeMy WebLinkAboutOrdinances (O-00-1231)-08/15/2000
ORDINANCE 0-00-1231
AN ORDINANCE REPLACING ORDINANCE 0-95-990 AND ORDINANCE 0-95-998,
AMENDING CHAPTER 50, ARTICLE II, FLOOD HAZARD REGULATIONS, OF THE
COLLEYVILLE CODE
WHEREAS, the City Council deems it is in the best interest of the City to modify its
flood area hazard regulation as provided herein.
NOW, THEREFORE, BE IT ORDAINED BY THE CITY COUNCIL OF THE CITY OF
COLLEYVILLE, TEXAS:
FLOOD HAZARD AREA REGULATIONS
A. STATUTORY AUTHORIZATION
The Legislature of the State of Texas has in statutes delegated the
responsibility of local governmental units to adopt regulations designed to
minimize flood losses. Therefore, the City Council of the City of Colleyville,
Texas does ordain as follows:
B. FINDINGS OF FACT
(1) The flood hazard areas of the City of Colleyville are subject to
periodic inundation which may result 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.
(2) 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 hazards areas by
uses vulnerable to floods and hazardous to other lands because
they are inadequately elevated, f1oodproofed or otherwise protected
from flood damage.
c. STATEMENT OF PURPOSE
It is the purpose of this ordinance 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:
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(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 flood-prone 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.
D. METHODS OF REDUCING FLOOD LOSSES
In order to accomplish its purposes, this ordinance 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 flood waters;
(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.
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E. DEFINITIONS
Unless specifically defined below, words or phrases used in this ordinance
shall be interpreted to give them the meaning they have in common usage
and to give this ordinance its most reasonable application.
(1) Appeal-means a request for a review of the Floodplain
Administrator's interpretation of any provisions of this ordinance or
a request for a variance.
(2) 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.
(3) 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.
(4) Area of Shallow Flooding-means a designated AO, AH, or VO
zone on a community's Flood Insurance Rate Map (FIRM) with a
one percent or greater annual chance of flooding to an average
depth of one to three 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.
(5) Area of Special Flood Hazard-is the land in the floodplain within a
community subject to a one-percent or greater chance of flooding in
any given year.
(6) Base Flood-means the flood having a one-percent chance of being
equaled or exceeded in any given year.
(7) Basement-means any area of the building having its lowest floor
subgrade (below ground level) on all sides.
(8) 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.
(9) Development-means any man-made change in improved and
unimproved real estate, including but not limited to buildings or
other structures, mining, dredging, filling, grading, paving,
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excavation or drilling operations or storage of equipment or
materials.
(10) Elevated Building-means a non basement building (i) built, in the
case of a building in Zones A 1-30, AE, A, A99, AD, AH, B, C, X,
and D, to have the top of the elevated floor, or in the case of a
building in Zones V1-30, VE, or V, to have the bottom of the lowest
horizontal structure member of the elevated floor elevated above
the ground level by means of pilings, columns (posts and piers), or
shear walls parallel to the floor of the water and (ii) adequately
anchored so as not to impair the structural integrity of the building
during a flood of up to the magnitude of the base flood. In the case
of Zones A 1-30, AE, A, A99, AD, AH, B, C, X, and D, "elevated
building" also includes a building elevated by means of fill or solid
foundation perimeter walls with openings sufficient to facilitate the
unimpeded movement of flood waters. In the case of Zones V1-30,
VE, or V, "elevated building" also includes a building otherwise
meeting the definition of "elevated building," even though the lower
area is enclosed by means of breakaway walls if the breakaway
walls met the standards of Section 60.3 (e)(5) of the National Flood
Insurance Program regulations.
(11) 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 I, 1975, for
FIRMs effective before that date, "existing construction" may also
be referred to as"existing structures."
(12) 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.
(13) 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).
(14) Flood or Flooding-means a general and temporary condition of
partial or complete inundation of normally dry land areas from:
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(a) the overflow of inland or tidal waters.
(b) the unusual and rapid accumulation or runoff of
surface waters from any source.
(15) Flood Hazard Boundary Map (FHBM)-means an official map of a
community, issued by the Federal Insurance Administration, where
the areas within the boundaries of special flood hazards have been
designated as Zone A.
(16) Flood Insurance Rate Map (FIRM)-means an official map of a
community, on which the Federal Emergency Management Agency
has delineated both the areas of special flood hazards and the risk
premium zones applicable to the community.
(17) Flood Insurance Study-is the official report provided by the
Federal Emergency Management Agency. The report contains
flood profiles, water surface elevation of the base flood, as well as
the Flood Boundary-Floodway Map.
(18) Floodplain or Flood-Prone Area-means any land area susceptible
to being inundated by water from any source (see definition of
flooding).
(19) Floodplain Manaaement-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.
(20) Floodplain Administrator-means, for the purposes of the City of
Colleyville's Floodplain Management Ordinance, the City
Engineer.
(21) Flood Plain Manaaement Reaulations-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.
(22) 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 areas within a community subject
to a "special flood hazard" and the extent of the depths of
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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.
(23) Flood ProofinQ-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.
(24) Floodwav (ReQulatorv Floodwav)-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 (one foot) a
designated height.
(25) Functionallv 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.
(26) HiQhest Adiacent Grade - means highest natural elevation of the
ground surface prior to construction next to the proposed walls of a
structure.
(27) Historic Structure-means any structure that is:
(a) Listed individually in the National Register of Historic
Places (a listing maintained by the Department of
Interior) or preliminarily determined by the Secretary
of Interior as meeting the requirements for individual
listing on the National Register;
(b) Certified or preliminarily determined by the Secretary
of 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;
(c) Individually listed on a state inventory of historic
places in states with historic preservation programs
which have been approved by the Secretary of
Interior; or
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(d) Individually listed on a local inventory of historic
places in communities with historic preservation
programs that have been certified either:
(i) By an approved state program as determined by
the Secretary of Interior or;
(ii) Directly by the Secretary of Interior in states
without approved programs.
(28) 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.
(29) Levee System-means a flood protection system which consists of
a levee, or levees, and associated structure, such as closure and
drainage devices, which are constructed and operated in
accordance with sound engineering practices.
(30) Lowest Floor-means the lowest floor of the lowest enclosed area
(including basement). An unfinished or flood resistant enclosure,
used solely for parking or 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.
(31) 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".
(32) Manufactured Home Park or Subdivision-means a parcel (or
contiguous parcels) of land divided into two or more manufactured
home lots for rent or sale.
(33) Mean Sea Level-means, for purposes of the National Flood
Insurance Program, the National Geodetic Vertical Datum (NGVD)
of 1929 or other datum, to which base flood elevations shown on a
community's Flood Insurance Rate Map are referenced.
(34) 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
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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.
(35) 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.
(36) 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.
(37) Start of Construction- means for other than new construction or
substantial improvements under the Coastal Barrier Resources Act
(Pub. L. 97-348), includes substantial improvements 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 a
permanent construction of a structure on a site, such as the pouring
of a 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 a 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.
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(38) Structure-means a walled and roofed building, including a gas or
liquid storage tank, that is principally above ground, as well as a
manufactured home.
(39) Substantial Damaae- 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 damage occurred.
(40) 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
includes structures which have incurred "substantial damage",
regardless of the actual repair work performed. The term does not,
however, include either: (a) 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 enforcement official and which are the minimum
necessary conditions or (b) Any alteration of a "historic structure",
provided that the alteration will not preclude the structure's
continued designation as a "historic structure."
(41) Variance- is a grant of relief to a person from the requirement of
this ordinance when specific enforcement would result in
unnecessary hardship. A variance, therefore, permits construction
or development in a manner otherwise prohibited by this ordinance.
(For full requirements see section 60.6 of the National Flood
Insurance Program regulations.)
(42) 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 is presumed to be in violation until such time as that
documentation is provided.
(43) Water Surface Elevation-means the height, in relation to the
National Geodetic Vertical Datum (NGVD) of 1929 (or other datum,
where specified), of floods of various magnitudes and frequencies
in the floodplains of coastal or riverine areas.
F. LANDS TO WHICH THIS ORDINANCE APPLIES
This ordinance shall apply to all areas of special flood hazard within the
jurisdiction of the City of Colleyville, Texas.
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G. BASIS FOR ESTABLISHING THE AREAS OF SPECIAL FLOOD
HAZARD
The areas of special flood hazard identified by the Federal Emergency
Management Agency in a scientific and engineering report entitled, "The
Flood Insurance Study for tho City of Colloyvillo Tarrant County", dated
June 1, 1982, August 23, 2000 with accompanying Flood Insurance Rate
Maps and Flood Boundary- Floodway Maps (FIRM and FBFM) and any
revisions thereto are hereby adopted by reference and declared to be part
of this ordinance.
H. ESTABLISHMENT OF DEVELOPMENT PERMIT
A Development Permit shall be required to ensure conformance with the
provisions of this ordinance.
I. COMPLIANCE
No structure or land shall hereafter be located, altered, or have its use
changed without full compliance with the terms of this ordinance and other
applicable regulations.
J. ABROGATION AND GREATER RESTRICTIONS
This ordinance is not intended to repeal, abrogate, or impair any existing
easements, covenants, or deed restrictions. However, where this
ordinance and another ordinance, easement, covenant, or deed restriction
conflict or overlap, whichever imposes the more stringent restrictions shall
prevail.
K. INTERPRETATION
In the interpretation and application of this ordinance, 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.
L. WARNING AND DISCLAIMER OF LIABILITY
The degree of flood protection required by this ordinance 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 ordinance does not imply that land outside the areas of
special flood hazards or uses permitted such areas will be free from
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flooding or flood damages. This ordinance shall not create liability on the
part of the City of Colleyville, Texas, or any officer or employee thereof for
any flood damages that result from reliance on this ordinance or any
administrative decision lawfully made thereunder.
M. DESIGNATION OF THE FLOODPLAIN ADMINISTRATOR
The City Engineer is hereby appointed to administer and implement the
provisions of this ordinance and other appropriate sections of 44 CFR
(National Flood Insurance Program Regulations) pertaining to floodplain
management.
N. DUTIES AND RESPONSIBILITIES OF THE FLOODPLAIN
ADMINISTRATOR
Duties and responsibilities of the Floodplain Administrator shall include,
but not be limited to:
(1) Maintain and hold open for public inspection all records pertaining
to the provisions of this ordinance.
(2) Review permit application to determine whether proposed building
sites, 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 ordinance.
(4) Review permits for proposed development to assure that all
necessary permits have been obtained from those Federal, State,
and 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. The person contesting the location of
the boundary shall be given a reasonable opportunity to appeal the
interpretation as provided in subsection P. (2) of this ordinance.
(6) Notify, in riverine situations, adjacent communities and the State
Coordinating Agency, which is the Texas Natural Resource
Conservation Commission, prior to any alteration or relocation of a
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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 subsection G, 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 subsection a. of this
ordinance.
(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 A 1-30 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 provisions of 44 CFR Chapter 1, Section 65.12, of the
National Flood Insurance Program regulations, a community may
approve certain development in Zones A 1-30, AE, AH, on the
community's FIRM which increases the water surface elevation of
the base flood by more than one foot, provided that the community
first applies for a conditional FIRM revision through FEMA.
O. PERMIT PROCEDURES
(1) Application for a 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.
(a) Elevation (in relation to mean sea level), of the lowest
floor (including basement) of all new and substantially
improved structures;
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(b) Elevation in relation to mean sea level to which any
nonresidential structure shall be flood-proofed;
(c) A certificate from a registered professional engineer,
registered in the State of Texas, that the
nonresidential flood-proofed structure shall meet the
flood proofing criteria of subsection Q (2)(b);
(d) Description of the extent to which any watercourse or
natural drainage will be altered or relocated as a
result of proposed development
(e) Maintain a record of all such information in
accordance with subsection N. (1) of this ordinance.
(2) Approval or denial of a Development Permit by the Floodplain
Administrator shall be based on all of the provisions of this
ordinance and the following relevant factors:
(a) The danger to life and property due to flooding or
erosion damage;
(b) The susceptibility of the proposed facility and its
contents to flood damage and the effect of such
damage on the individual owner;
(c) The danger that materials may be swept onto other
lands to the injury of others;
(d) The compatibility of the proposed use with existing
and anticipated development;
(e) The safety of access to the property in times of flood
for ordinary and emergency vehicles;
(f) The cost 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;
(g) The expected heights, velocity, duration, rate of rise
and sediment transport of the flood waters and the
effects of wave action, if applicable, expected to the
site;
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(h) The necessity to the facility of a waterfront location,
where applicable;
(i) The availability of alternative locations, not subject to
flooding or erosion damage, for the proposed use;
U) The relationship of the proposed use to the
comprehensive plan for that area.
P . VARIANCE PROCEDURE
(1) The Zoning Board of Adjustment as established by the community
shall hear and render judgement on requests for variances from the
requirements of this ordinance.
(2) The Zoning Board of Adjustment shall hear and render judgement
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
ordinance.
(3) Any person or persons aggrieved by the decision of the Zoning
Board of Adjustment may appeal such decision in the courts of
competent jurisdiction.
(4) 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.
(5) Variances may be issued for the reconstruction, rehabilitation or
restoration of structures listed on the National Register of Historic
Places or State Inventory of Historic Places, without regard to the
procedures set forth in the remainder of this section.
(6) Variances may be issued for new construction and substantial
improvements to be erected on a lot of one-half 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 subsection O. (2) of this ordinance have been fully
considered. As the lot size increases beyond the one-half acre, the
technical justification required for issuing the variance increases.
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(7) Upon consideration of the factors noted above and the intent of this
ordinance, the Zoning Board of Adjustment may attach such
conditions to the granting of variances as it deems necessary to
further the purpose and objectives of this ordinance (subsections C.
and D. of this ordinance).
(8) Variances shall not be issued within any designated floodway if any
increase in flood levels during the base flood discharge would
result.
(9) 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.
(10) Prerequisites for granting variances:
(a) Variances shall only be issued upon a determination
that the variance is the minimum necessary,
considering the flood hazard, to afford relief.
(b) Variances shall only be issued upon, (1) showing a
good and sufficient cause; (2) a determination that
failure to grant the variance would result in
exceptional hardship to the applicant, and (3) a
determination that granting of a variance will not result
in increased flood heights, additional threats to public
safety, extraordinary public expense, create
nuisances, cause fraud on or victimization of the
public, or conflict with existing local laws or
ordinances.
(c) Any application to whom a variance is granted shall
be given written notice that the structure will be
permitted to be built with the lowest floor elevation no
more than 3 feet 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.
(11) Variances may be issued by a community for new construction and
substantial improvements and for other development necessary for
the conduct of a functionally dependent use provided that (i) the
criteria outlined in subsection P. (1 )-(9) are met, and (ii) the
structure or other development is protected by methods that
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minimize flood damages during the base flood and create no
additional threats to public safety.
Q. PROVISIONS FOR FLOOD HAZARD REDUCTION
(1) General Standards
In all areas of special flood hazards the following provisions are required
for all new construction and substantial improvements.
(a) 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;
(b) All new construction or substantial improvements shall be
constructed by methods and practices that minimize flood damage;
(c) All new construction or substantial improvements shall be
constructed with materials and utility equipment resistant to flood
damage;
(d) 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;
(e) All new and replacement water supply systems shall be designed to
minimize or eliminate infiltration of flood waters into the system;
(f) New and replacement sanitary sewage systems shall be designed
to minimize or eliminate infiltration of flood waters into the system
and discharge from the systems into flood waters; and,
(g) On-site waste disposal systems shall be located to avoid
impairment to them or contamination from them during flooding.
(2) Specific Standards
I n all areas of special flood hazards where base flood elevation data has
been provided as set forth in (i) subsection G., (ii) subsection N. (8), or (iii)
subsection a. (4) (c), the following provisions are required:
(a) Residential Construction-New construction or substantial
improvement of any residential structure shall have the lowest floor
(including basement), elevated 2 feet above, or as otherwise
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determined by the Floodplain Administrator, the base flood
elevation. A registered professional engineer or registered land
surveyor, registered in the State of Texas, shall submit a
certification to the Floodplain Administrator that the standard of this
subsection as proposed in subsection O. (1) (a), is satisfied.
(b) 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, registered in the State of Texas, 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 ordinance. A record of such certification
which includes the specific elevation (in relation to mean sea level)
to which structures are flood proofed shall be maintained by the
Floodplain Administrator.
(c) 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:
(i) 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 shall be
provided.
(ii) The bottom of all openings shall be no higher than
one foot above grade.
(iii) Openings may be equipped with screens, louvers,
valves, or other coverings or devices provided that
they permit the automatic entry and exit of
floodwaters.
Ordinance 0-00-1231
Page 18 of 22
(d) Manufactured Homes-
(i) 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 not be 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.
(ii) Require that manufactured homes that are placed
or substantially improved within Zones A1-30, AH,
and AE on the community's FIRM on sites (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 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 2 feet above, or as otherwise
determined by the Floodplain Administrator, the
base flood elevation and be securely anchored to
an adequately anchored foundation system to
resist flotation, collapse, and lateral movement.
(iii) Require that manufactured homes be placed or
substantially improved on sites in an existing I
manufactured home park or subdivision within
Zones A1-30, AH, AE on the community's FIRM
that are not subject to the provisions of subsection
a. (2) (d) "Manufactured Homes" of this ordinance
be elevated so that either:
(1) the lowest floor is 2 feet above, or as
otherwise determined by the Floodplain
Administrator, the base flood elevation, or
Ord ihance 0-00-1231
Page 19 of 22
(2) 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.
(e) Recreational Vehicles-Require that recreational vehicles placed on
sites within Zones A 1-30, AH, and AE on the community's FIRM
either (1) be on the site for fewer than 180 consecutive days, (2) be
fully licensed and ready for highway use, or (3) meet the
requirements of subsection O. (1), and the elevation and anchoring
requirements for "manufactured homes" in subsection a. (2) (d) of
this ordinance. 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.
(3) STANDARDS FOR SUBDIVISION PROPOSALS
(a) All subdivision proposals including the placement of manufactured
home parks and subdivisions shall be consistent with subsections
B., C., and D. of this ordinance.
(b) All proposals for the development of subdivisions including the
placement of manufactured home parks and subdivisions shall
meet Development Permit requirements of subsection H., 0., and
a. of this ordinance.
(c) Base flood elevation data shall be generated 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 subsection G., or subsection N. (8) of this
ordinance.
(d) All subdivision proposals including the placement of manufactured
home parks and subdivisions shall have adequate drainage
provided to reduce exposure to flood hazards.
(e) 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 0-00-1231
Page 20 of 22
(4) STANDARDS FOR AREAS OF SHALLOW FLOODING AO/AH ZONES
Located within the areas of special flood hazard established in subsection
G., are areas designated as shallow flooding. These areas have special
flood hazards associated with base flood depths of 1 to 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:
(a) All new construction and substantial improvements to
residential structures 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).
(b) All new construction and substantial improvements to
nonresi-dential structu res;
(i) 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;
(ii) together with attendant utility and sanitary facilities
be designed so that below the base flood level the
structure is watertight with the 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.
(c) A registered professional engineer, registered in the
State of Texas, shall submit a certification to the
Floodplain Administrator that the standards of this
Section, as proposed in subsection O. (1) (a) are
satisfied.
(d) Require within Zones AH or AO adequate drainage
paths around structures on slopes, to guide
floodwaters around and away from proposed
structures.
Ordinance 0-00-1231
Page 21 of 22
(5) FLOODWAYS
Floodways located within areas of special flood hazard established in
subsection G., 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:
(a) 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.
(b) If subsection a. (5) (a) above is satisfied, all new
construction and substantial improvements shall
comply with all applicable flood hazard reduction
provisions of subsection a.
(c) 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.
AND IT IS SO ORDERED.
public hearing being conducted on the
,2000.
The '2t",;~d rei'ding and public hearing being conducled on the JS-tb
~ ~5-r , 2000.
21}..d
day of
day of
Ordinance 0-00-1231
Page 22 of 22
ATTEST:
CITY OF COLLEYVILLE
J~
k~~
Mayor
Jea arris, TRMC, CMC
City Secretary
Ross T. Foster
City Attorney