The Legislature of the State of Texas has in 16.311 V.T.C.S.
delegated the responsibility to local governmental units to adopt
regulations designed to minimize flood losses.
(1995 Code of Ordinances, Chapter 3, Article 3.1200,
Section 3.1201)
(a)
The
flood hazard areas of the City of DeSoto 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.
(1995 Code of Ordinances, Chapter 3, Article 3.1200,
Section 3.1202)
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 flood-prone areas in such a manner as to minimize future flood
blight areas; and
(7)
Insure
the potential buyers are notified that property is in a flood area.
(1995 Code of Ordinances, Chapter 3, Article 3.1200,
Section 3.1203)
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
protection 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 flood waters or which may increase flood hazards to other land.
(1995 Code of Ordinances, Chapter 3, Article 3.1200,
Section 3.1204)
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.
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.
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.
means a request for a review of the floodplain administrator’s
interpretation of any provisions of this article or a request for
a variance.
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.
means the land area that would be inundated by the 1-percent-annual
chance (100-year) flood based on future conditions hydrology.
means a designated AO, AH, or VO zone on a community’s
flood insurance rate map (FIRM) with a one percent (1%) or greater
annual chance of flooding to an average depth of one (1) to three
(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.
is the land in the floodplain within a community subject
to a one percent (1%) 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 ratemaking has been completed in preparation
for publication of the FIRM, zone A usually is refined into zones
A, AE, AO, AH, A1-99, VO, V1-30, VE or V.
means the flood having a one-percent chance of being equaled
or exceeded in any given year.
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.
means any area of the building having its floor subgrade
(below ground level) on all sides.
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.
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.
means any manmade change to improved or unimproved real estate,
including but not limited to, buildings or other structures, mining,
dredging, filling, grading, paving, excavation, or drilling operations.
means a nonbasement building:
Built, in the case of a building in zones A1-30, AE, A, A99,
AO, 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 (post and piers),
or shear walls parallel to the floor of the water; and
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 A1-30, AE, A, A99, AO, AH, B, C, X, 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 floodwaters. 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 meet the standards of Section
60.3(e)(5) of the National Flood Insurance Program regulations.
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 l, 1975, for FIRMs effective
before that date. “Existing construction” may also be
referred to as “existing structures.”
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.
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).
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.
see flood elevation study.
means a general and temporary condition of partial or complete
inundation of normally dry land areas from:
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 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.
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.
shall mean the moving of any material within a floodplain
which alters the existing surface configuration, i.e., the moving
of existing soils or other materials from one area of the floodplain
to another area within the floodplain.
shall mean the transportation of soil or other materials
from outside to within the floodplain.
means any land area susceptible to being inundated by water
from any source (see definition of flooding).
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.
see regulatory floodway.
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 shipbuilding
and ship repair facilities, but does not include long-term storage
or related manufacturing facilities.
means the highest natural elevation of the ground surface
prior to construction next to the proposed walls of a structure.
means any structure that is:
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;
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
[of the Interior] to qualify as a registered historic district;
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
Individually listed on a local inventory of historic places
in communities with historic preservation programs that have been
certified either:
means a manmade 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.
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.
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.
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.
For floodplain management purposes the term “manufactured home”
also includes park trailers, travel trailers, and other similar vehicles
placed on a site for greater than one hundred eighty (180) consecutive
days. For insurance purposes the term “manufactured home”
does not include park trailers, travel trailers, and other similar
vehicles.
means a parcel (or contiguous parcels) of land divided into
two or more manufactured home lots for rent or sale.
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.
means, for floodplain management purposes structures for
which the “start of construction” commenced on or after
the effective date of a floodplain management regulation adopted by
a community.
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.
means a vehicle which is:
Built on a single chassis;
400 square feet or less when measured at the largest horizontal
projections;
Designed to be self-propelled or permanently towable by a light
duty truck; and
Designed primarily not for use as a permanent dwelling but as
temporary living quarters for recreational, camping, travel, or seasonal
use.
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.
means relating to, formed by, or resembling a river (including
tributaries), stream, brook, etc.
see area of special flood hazard.
(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,
placement, or other improvement was within one hundred eighty (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.
means a walled and roofed building, including a gas or liquid
storage tank, that is principally above ground, as well as a manufactured
home.
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.
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:
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
Any alteration of a “historic structure,” provided
that the alteration will not preclude the structure’s continued
designation as a “historic structure.”
is a grant of relief to a person from the requirements of
this article when specific enforcement would result in unnecessary
hardship. A variance, therefore, permits construction or development
in a manner otherwise prohibited by this article. (For full requirements
see Section 60.6 of the National Flood Insurance Program (NFIP) regulations.)
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 NFIP is presumed to be in violation until such time
as that documentation is provided.
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.
(1995 Code of Ordinances, Chapter 3, Article 3.1200,
Section 3.1205; Ordinance 1982-14 adopted 7/15/14)
(a)
Lands
to Which These Provisions Apply.
These provisions shall
apply to all areas of special flood hazard within the jurisdiction
of the city.
(b)
Basis
for Establishing the Areas of Special Flood Hazard.
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 Dallas County,
Texas and Incorporated Areas,” dated July 7, 2014, with accompanying
flood insurance rate maps (FIRMs) dated July 7, 2014, and any revisions
thereto are hereby adopted by reference and declared to be a part
of this article.
(c)
Establishment
of Development Permit.
(1)
A development permit shall be required to ensure conformance with
the provisions of this article. This permit requirement shall apply
to any development, as previously defined, within the floodplain.
(2)
The development permit fee shall be two hundred dollars ($200.00)
plus twenty dollars ($20.00) per acre.
(d)
Compliance.
No structure or land shall hereafter be subdivided, located,
altered, or have its use changed without full compliance with the
terms of this article and other applicable regulations including,
but not limited to, the zoning ordinance, official maps, health codes,
subdivision ordinance, building codes, and other regulations which
apply to uses within the jurisdiction of this article.
(e)
Abrogation
and Greater Restrictions.
This article is not intended
to repeal, abrogate, or impair any existing easements, covenants,
or deed restrictions. However, where this article and another conflict
or overlap, whichever imposes the more stringent restrictions shall
prevail.
(g)
Warning
and Disclaimer of Liability.
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 manmade 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 city or any
official or employee thereof for any flood damages that result from
reliance on these provisions or any administrative decision lawfully
made thereunder.
(1995 Code of Ordinances, Chapter 3, Article 3.1200,
Section 3.1206; Ordinance 1982-14 adopted 7/15/14)
(a)
Designation
of the Floodplain Administrator.
The city engineer is
hereby appointed the floodplain administrator to administer and implement
the provisions of this article and other appropriate sections of 44
CFR (National Flood Insurance Program Regulations) pertaining to floodplain
management.
(b)
Duties
and Responsibilities of the Floodplain Administrator.
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 application to determine whether proposed building
site 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 Texas Water Commission, 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 3.1206(b) 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 Section 3.1208.
(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 (1) foot
at any point within the community.
(c)
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 locations,
dimensions, and elevation of proposed landscape alterations, existing
and proposed structures 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;
(B)
Elevation in relation to mean sea level to which any nonresidential
structure shall be floodproofed;
(C)
A certificate from a registered professional engineer or architect that the nonresidential floodproofed structure shall meet the floodproofing criteria of Section 3.1208(b)(2);
(D)
Description of the extent to which any watercourse or natural drainage
will be altered or relocated as a result of proposed development;
and
(F)
The floodplain administrator may require the developer to submit
three (3) cross sections, if it is determined this information is
necessary to properly evaluate the application, and may include, but
is not limited to:
(G)
The floodplain administrator shall evaluate the proposed project
in relation to flood heights and velocities; the seriousness of flood
damage to the use, and the adequacy of the plans for protection. Other
technical information may be required by the city engineer to properly
evaluate the site and shall be furnished by the developer upon request
by the city as follows:
(i)
Estimate the discharge of the base flood;
(ii)
Determine the specific flooding threat at the site of the proposed
subdivision and determine whether the subdivision is located in a
floodway or flood fringe area by:
a.
Calculation of water surface elevations and flood protection
elevations based upon a hydraulic analysis of the capacity of the
stream channel and overbank areas to convey the base flood. Flood
protection elevations shall be two (2) feet above the water surface
elevations of the base flood; and
b.
Computation of the floodway required to convey the flood without
increasing flood heights upstream or downstream without damage to
existing or reasonably anticipated future development.
(H)
The developer or property owner may be required to prepare all documentation
and technical data for submittal by the city to the Federal Emergency
Management Agency (FEMA) for issuance of a letter or map revision
removing the land or structure from the area of special flood hazard.
(2)
Approval or denial of a development permit by the floodplain administrator
shall be based on all of the provisions of this article 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 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;
(G)
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;
(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;
(J)
The relationship of the proposed use to the comprehensive plan for
that area.
(d)
Variance
Procedures.
(1)
The appeal board as established by the community shall hear and render
judgment on requests for variances from the requirements of this article.
(2)
The appeal board 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.
(3)
Any person or persons aggrieved by the decision of the appeal board
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 the state inventory of historic places, without regard to
the procedures set forth in the remainder of this article.
(6)
Variances may be issued for new construction and substantial improvements to be erected on a lot of one-half (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 subsection (c)(2) above have been fully considered. As the lot size increases beyond the one-half (1/2) acre, the technical justification required for issuing the variance increases.
(7)
Upon consideration of the factors noted above and the intent of this article, the appeal board may attach such conditions to the granting of variances as it deems necessary to further the purpose and objectives of Section 3.1203 of this article.
(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:
(i)
A showing of 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, extraordinary
public expense, create nuisances, cause fraud on or victimization
of the public, or conflict with existing local laws or ordinances;
and
(C)
Any applicant to whom a variance is granted shall be given written
notice that the structure will be permitted to be built with a 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.
(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:
(1995 Code of Ordinances, Chapter 3, Article 3.1200,
Section 3.1207; Ordinance 1982-14 adopted 7/15/14)
(a)
General
Standards.
In all areas of special flood hazards the
following provisions are required for all new construction and substantial
improvements:
(1)
All new construction and 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 discharges 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.
(8)
No development shall be permitted within the floodplain fringe or
floodway that requires the use of off-site fill material.
(b)
Specific
Standards.
In all areas of special flood hazards where base flood elevation data has been provided as set forth in Sections 3.1206(b), 3.1207(b)(8), and 3.1208(c)(3), the following provisions are required:
(1)
Residential Construction.
New construction or substantial improvement of any residential structure shall have the lowest floor, including basement, elevated 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 these standards as proposed in Section 3.1207(c)(1)(A), are satisfied.
(2)
Nonresidential Construction.
New construction or substantial
improvement of any commercial, industrial, or other nonresidential
structure shall either have the lowest floor, including basement,
elevated 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
method 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 subject
to flooding shall be designed to automatically equalize hydrostatic
flood forces on exterior walls by allowing for the entry and exit
of floodwaters. Designs for meeting this requirement must either be
certified by a registered professional engineer or architect or meet
or exceed the following minimum criteria:
(A)
A minimum of two (2) openings having a total net area of not less
than one (1) square inch for every square foot of enclosed area subject
to flooding shall be provided.
(B)
The bottom of all openings shall be no higher than one (1) foot above
grade.
(C)
Openings may be equipped with screens, louvers, valves, or other
coverings or devices provided that they permit the automatic entry
and exit of floodwaters.
(4)
Manufactured Homes.
(A)
Require that all manufactured homes to be placed within zone A, shall
be installed using methods and practices which minimize flood damage.
For the purpose 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 be placed or substantially improved on sites in an existing manufactured home park or subdivision with zones A1-30, AH and AE on the community’s FIRM that are not subject to the provisions of subsection (4) of this section be elevated so that either:
(i)
The lowest floor of the manufactured home is at or 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.
(c)
Standards
for Subdivision Proposals.
(3)
Base flood elevation data shall be generated for subdivision proposals and other proposed development including manufactured home parks and subdivisions which is greater than two (2) lots or two (2) acres, whichever is lesser, if not otherwise provided pursuant to Section 3.1206(b) or Section 3.1207(b)(8) of this article. Base flood elevation data may be required by the floodplain administrator for small subdivisions if necessary to determine the potential flood hazard for the development.
(4)
All subdivision proposals including manufactured home parks and subdivisions
shall have adequate drainage provided to reduce exposure to flood
hazards.
(5)
All subdivision proposals including 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.
(6)
Building sites, residences, motels, resorts, and similar uses for
human occupancy shall not be permitted in floodway areas. Sites for
these uses may be permitted outside the floodway if the sites are
elevated to a height of at least two (2) feet above the elevation
of the base flood or provisions otherwise made for elevation or adapting
structures to achieve the same result. No soil or other fill material
may be transported from outside of the floodplain to within the floodplain.
Required fill areas must extend fifteen (15) feet beyond the limits
of intended structures. Residential structures must have the lowest
floor of the structure basement two (2) feet above the elevation of
the base flood.
(d)
Standards
for Areas of Shallow Flooding (AO/AH Zones).
Located within the areas of special flood hazard established in Section 3.1206(b) are areas designated as shallow flooding. These areas have special flood hazards associated with base flood depths of one (1) to three (3) feet where a clearly defined channel does not exist and where the path of flooding is unpredictable and where velocity flow may be evident. Such flooding is characterized by ponding or sheet flow; therefore, the following provisions apply:
(1)
All new construction and substantial improvements of residential
structures 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 (2') if no
depth number is specified).
(2)
All new construction and substantial improvements of nonresidential
structures shall:
(A)
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 (2') if no depth
number is specified); or
(B)
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 or 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 3.1207(c)(1)(A) are satisfied.
(4)
Require within zones AH and AO, adequate drainage paths around structures
on slopes, to guide floodwaters around and away from proposed structures.
(e)
Floodways.
Floodways located within areas of special flood hazard established in Section 3.1206(b), 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 section.
(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.
(1995 Code of Ordinances, Chapter 3, Article 3.1200,
Section 3.1208; Ordinance 1982-14 adopted 7/15/14)
