INSTRUCTIONS FOR CREATING YOUR COMMUNITY’S ORDINANCE
1) PROVIDE COMMUNITY SPECIFIC INFORMATION AS REQUESTED IN
BRACKETS
This model ordinance contains references in {red brackets} that must be replaced with
community specific information such as your community's name, address, or name of the
responsible party.
2) UPDATE CROSS REFERENCES
Cross references to other sections are shown in red throughout this document to facilitate
location for ensuring changes are made to match actual numbering used by your
community and are not intended to reflect a suggested final format.
3) DETERMINE IF YOUR COMMUNITY WANTS TO ADOPT HIGHER
STANDARDS RECOMMENDED BY THE STATE OF NEVADA
This model ordinance meets the minimum standards required to participate in the
National Flood Insurance Program. Community adoption of higher standards can be
applied towards credit under the Community Rating System (CRS) program and result in
reduced premiums for the entire community. The State of Nevada recommends:
Daily Fine – Appendix 2.0 A recommends a substantial daily fine for each day
violation continues.
Determining BFE’s in Unnumbered A Zones - Appendix 2.0 B requires, in the
absence of any other sources, that the community develop base flood elevations
using FEMA 265 guidance (Managing Floodplain Development in Approximate
Zone A Areas, A guide for Obtaining and Developing Base (100-year) Flood
Elevations, 1995).
Limiting Increase in Base Flood Elevation – Appendix 2.0 C decreases the
allowable increase in base flood elevations due to cumulative development from
one (1) foot to one-half (1/2) foot.
Freeboard – - Appendix 2.0 D increases the required elevation and floodproofing
requirement from zero (0) to two (2) feet above base flood elevation or depth
indicated on the FIRM.
Determining Market Value of Existing Structures – Appendix 2.0 E defines a
specific method for determining Market Value of existing structures.
Increased Cost of Compliance (ICC) Coverage—Repetitive Loss Provisions –
Appendix 2.0 F provides the required definition of Substantial Damage to make
Increased Cost of Compliance flood insurance coverage available in repetitive
loss situations.
Non-conversion of Enclosed Areas Below the Lowest Floor – Appendix 2.0 G
provides the community a mechanism to ensure that areas below the lowest floor
will not be converted to living space without first becoming fully compliant with
floodplain management regulations.
5) DETERMINE IF YOUR COMMUNITY HAS SPECIAL REQUIREMENTS
Alluvial Fan Advisory – Appendix 1.0 provides a description of alluvial fan
flooding and specifies in writing that FEMA will not approve a Letter of Map
Revision based on Fill (LOMR-F) for structures on an alluvial fan.
Crawlspace Construction – Appendix 3.0 A defines construction criteria from
Technical Bulletin 11-01 (Crawlspace Construction for Buildings Located in
Special Flood Hazard Areas, 2001) to allow for crawlspace construction that will
not be considered a violation of Federal floodplain management regulations.
Without this language, a crawlspace constructed within special flood hazard areas
was considered by FEMA to meet the definition of “basement” (subgrade on all
sides) and was therefore a violation.
Garages and Accessory Structures – Appendix 3.0 B contains the definition for
accessory structures and construction requirements to allow for permitting of an
accessory structure within special flood hazard areas without a variance.
Appendix 3.0 B also provides specific language for attached and unattached
garages to allow for permitting of an unattached garage within special flood
hazard area without a variance.
Mudslide (i.e., mudflow) Prone Areas (Zone M) – Appendix 3.0 C provides
definitions and development requirements when Mudslide Prone Areas (Zone M)
have been identified in a community.
Erosion Prone Areas (Zone E) – Appendix 3.0 D provides definitions and
development requirements when Erosion Prone Areas (Zone E) have been
identified in a community.
6) PRIOR TO ADOPTION, SUBMIT DRAFT TO:
Other community departments, including Attorney’s office.
State Floodplain Manager, Nevada Division of Water Resources or FEMA
Region IX for review and approval.
7) AFTER ADOPTION SEND:
A copy of the adopted ordinance, with signature page(s), certified by the
City/County Clerk to FEMA Region IX
A copy of the adopted ordinance, with signature page(s) to the State Floodplain
Manager, Nevada Division of Water Resources.
MODEL
FLOODPLAIN MANAGEMENT
ORDINANCE
FOR
NEVADA COMMUNITIES
by
Nevada Floodplain Management Program
Nevada Division of Water Resources
901 South Stewart Street, Suite 2002, Carson City, Nevada 89701
July 2009
FLOODPLAIN MANAGEMENT
ORDINANCE
SECTION 1.0
STATUTORY AUTHORIZATION,
FINDINGS OF FACTS, PURPOSE AND METHODS
1.1
STATUTORY AUTHORIZATION
The legislature of the State of Nevada in Nevada Revised Statutes 278.020, 244A.057, and
543.020 confers upon local government units authority to adopt regulations designed to
promote the public health, safety, and general welfare of its citizenry. Therefore, the
{governing body} of {county or municipality} does hereby adopt the following floodplain
management regulations.
1.2
1.3
FINDING OF FACT
A.
The flood hazard areas of {county or municipality} are subject to periodic
inundation which results in loss of life and property, health and safety hazards,
disruption of commerce and governmental services, extraordinary public
expenditures for flood protection and relief, and impairment of the tax base, all of
which adversely affect the public health, safety and general welfare.
B.
These flood losses are caused by structures that are inadequately elevated,
floodproofed, or protected from flood damage. The cumulative effects of
obstructions in areas of special flood hazards, which increase flood heights and
velocities, also contribute to flood losses.
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:
A.
Protect human life and health;
B.
Minimize expenditure of public money for costly flood control projects;
C.
Minimize the need for rescue and relief efforts associated with flooding and
generally undertaken at the expense of the general public;
D.
Minimize prolonged business interruptions;
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1.4
E.
Minimize damage to public facilities and utilities such as water and gas mains,
electric, telephone and sewer lines, and streets and bridges located in areas of
special flood hazards;
F.
Help maintain a stable tax base by providing for the sound use and development of
areas of special flood hazard so as to minimize future blighted areas caused by
flood damage;
G.
Ensure potential buyers are notified of property located in areas of special flood
hazards;
H.
Ensure those who occupy the areas of special flood hazards assume responsibility
for their actions; and
I.
Maintain qualifying standards for participation in the National Flood Insurance
Program.
METHODS OF REDUCING FLOOD LOSSES
To accomplish its purposes, this ordinance includes methods and provisions to:
A.
Restrict or prohibit uses which are dangerous to health, safety, and property due to
water or erosion hazards, or which result in damaging increases in erosion or flood
heights or velocities;
B.
Require that land uses vulnerable to floods, including facilities which serve such
uses, be protected against flood damage at the time of initial construction;
C.
Control the alteration of natural floodplains, alluvial fans, stream channels, and
natural protective barriers, which help accommodate or channel flood waters;
D.
Control filling, grading, dredging, and other development which may increase flood
damage; and
E.
Prevent or regulate the construction of flood barriers which will unnaturally divert
floodwaters or which may increase flood hazards in other areas.
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SECTION 2.0
DEFINITIONS
Unless specifically defined below, words or phrases used in this ordinance shall be interpreted so
as to give them the meaning they have in common usage and to give this ordinance it’s most
reasonable application. A local ordinance need only include definitions of words actually used in
the ordinance.
Accessory Use
A use which is incidental and subordinate to the principal use of the parcel
of land on which it is located.
Alluvial Fan
A geomorphologic feature characterized by a cone or fan-shaped deposit of
clay, silt, sand, gravel, and boulders that have been eroded from mountain
slopes, transported by flood flows, and deposited on the valley floor.
Alluvial Fan
Flooding
Flooding occurring on the surface of an alluvial fan or similar land
form which originates at the apex and is characterized by high-velocity
flows: active processes of erosion, sediment transport, deposition, and
unpredictable flow paths.
Anchoring
A series of methods used to secure a structure to its footings or foundation
wall so that it will not be displaced by flood or wind forces.
Apex
The highest 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.
Appeal
A request for a review of the local Floodplain Administrator's interpretation
of any provisions of this ordinance.
Area of Shallow
Flooding
Designated Zones AO and AH 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.
Area of Special
Flood Hazard
See "Special Flood Hazard Area."
Base Flood
A flood which has a one percent chance of being equaled or exceeded in
any given year. (Also called the "100-year flood").
Base Flood
Elevation
The height in relation to mean sea level expected to be reached by
the waters of the base flood at pertinent points in the floodplain of riverine
areas.
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Basement
Any area of the building having its floor subgrade (below ground level) on
all sides. A sub grade crawlspace is considered a basement unless it meets
the minimum technical requirements defined in FEMA Technical Bulletin
11-01 (Crawlspace Construction for Buildings Located in Special Flood
Hazard Areas, 2001) and the community has adopted the standards of
Building
See structure.
Community
Any state or area or political subdivision thereof, or any Indian tribe or
authorized tribal organization, or authorized native organization, which has
authority to adopt and enforce flood plain management regulations for the
areas within its jurisdiction.
Community Rating A program developed by FIA to provide incentives for those
System (CRS)
communities in the Regular Program that have gone beyond the minimum
floodplain management requirements to develop extra measures to provide
protection from flooding.
Conditional Letter A letter from FEMA stating that a proposed structure that is not to
of Map Amendment be elevated by fill would not be inundated by the base flood if built
(CLOMA)
as proposed.
Conditional Letter
of Map Revision
(CLOMR)
Procedures by which contractors, developers and communities can
request review and determination by the Federal Insurance
Administrator of scientific and technical data for a proposed project, when
complete and functioning effectively would modify the elevation of
individual structures and parcels of land, stream channels, and floodplains
on the FIRM.
Conditional Letter
of Map Revision
(Based on Fill)
(CLOMR-F)
A letter from FEMA stating that a parcel of land or proposed
structure that is to be elevated by fill would not be inundated by
the base flood if fill is placed on the parcel as proposed or the
structure is built as proposed.
Critical Structures Any structure for which even a slight chance of flooding would reduce or
eliminate its designed function of supporting a community in an emergency.
Fire stations, hospitals, municipal airports, police stations, communication
antennas or towers, elder care facilities (retirement homes) fuel storage
facilities, schools designated as emergency shelters, fresh water and sewage
treatment facilities are some examples of critical structures.
Date of
Construction
The date that the building permit was issued provided the actual
start of construction, repair, reconstruction, or improvement was within 180
days of the permit date.
Designated
Floodway
The channel of a stream and the portion of the adjoining floodplain
designated by a regulatory agency to be kept free of further development to
provide for unobstructed passage of flood flows.
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Development
Any man-made 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 or storage of equipment
or materials located within the area of special flood hazard.
Digital Flood
Insurance Rate
Map (DFIRM)
The official map, in digital format, on which the Federal Emergency
Management Agency or Federal Insurance Administration has delineated
both the areas of special flood hazards and the risk premium zones
applicable to the community. The DFIRM is the legal equivalent of the
FIRM in communities where a DFIRM is available (see Flood Insurance
Rate Map).
Dry Floodproofing A floodproofing method used to design and construct buildings so as to
prevent the entrance of floodwaters.
Elevation
Certificate
The Elevation Certificate is required in order to properly rate postFIRM buildings, which are buildings constructed after publication of the
Flood Insurance Rate Map (FIRM), for flood insurance Zones A1-A30, AE,
AH, A (with BFE), VE, V1-V30, V (with BFE), AR, AR/A, AR/AE,
AR/A1-A30, AR/AH, and AR/AO. The Elevation Certificate is not
required for pre-FIRM buildings unless the building is being rated under the
optional post-FIRM Flood insurance rules.
Enclosure
That portion of an elevated building below the lowest elevated floor that is
either partially or fully shut-in by rigid walls.
Encroachment
The advance or infringement of uses, plant growth, excavation, fill,
buildings, permanent structures or development, storage of equipment and
materials, or any other physical object placed in the floodplain, that hinders
the passage of water or otherwise affects flood flows.
Erosion
The process of the gradual wearing away of any landmass. This peril is not
per se covered under the program. (See Flood-related erosion).
Existing
Manufactured
Home (mobile
Home) Park
Or Subdivision
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 a
Manufactured
Home (mobile
Home) Park
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,
construction of streets, and either final site grading or the pouring of
concrete pads).
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Federal Emergency The federal agency under which the National Flood Insurance
Management
Program (NFIP) is administered.
Agency (FEMA)
Federal Insurance
Administration
(FIA)
The government unit, a part of Federal Emergency Management
Agency (FEMA), that administers the National Flood Insurance
Program (NFlP).
Flash Flood
A flood that crests in a short period of time and is often characterized by
high velocity flows. It is often the result of heavy rainfall in a localized
area.
Flood, Flooding
Or Flood Waters
A general and temporary condition of partial or complete
inundation of normally dry land areas from the overflow of floodwaters; the
unusual and rapid accumulation or runoff of surface waters from any source
and mudslides (i.e., mudflows) and the condition resulting from floodrelated erosion.
Flood Control
Keeping flood waters away from specific developments or populated areas,
areas by the construction of flood storage reservoirs, channel alterations,
dikes and levees, bypass channels, or other engineering works.
Flood Hazard
Boundary
Map (FHBM)
An official map of a community, issued by the
Administrator, where the boundaries of the flood, mudslide
(i.e., mudflow) related erosion areas having special hazards have been
designated as Zones A, M, and /or E.
Flood Insurance
Rate Map (FIRM)
Official map on which the Federal Emergency Management
Agency or Federal Insurance Administration has delineated both the areas
of special flood hazards and the risk premium zones applicable to the
community. Includes Digital Flood Insurance Rate Map (DFIRM) in
communities where a DFIRM is available (see Digital Flood Insurance Rate
Map).
Flood Insurance
Study (FIS)
The official report provided by the Federal Insurance
Administration that includes flood profiles, the Flood Insurance Rate Map,
and the water surface elevation of the base flood.
Floodplain and
Flood-Prone Area
Any land area susceptible to being inundated by waters from
any source. (See Flooding).
Floodplain
Administrator
The community official designated by title to administer and enforce the
floodplain management regulations. The Floodplain Administrator for
{community, governing body} is defined in Sub-section 4.1 (Designation of
the Local Floodplain Administrator) of this ordinance to be the {position
title}.
Floodplain
Management
The operation of an overall program of corrective and
preventive measures for reducing flood damage and preserving and
6
enhancing, where possible, natural resources in the floodplain, including but
not limited to emergency preparedness plans, flood control works and
floodplain management plans, regulations and ordinances.
Floodplain
Management
Regulations
This ordinance, and any federal, state or local regulations
plus community zoning ordinances, subdivision regulations,
building codes, health regulations, special purpose ordinances (such as a
grading and erosion control) and other applications of police power which
control development in flood-prone areas to prevent and reduce flood loss
and damage.
Floodproofing
Any combination of structural and nonstructural additions, changes, or
adjustments to structures which reduce or eliminate flood damage to real
estate or improved property, water and sanitary facilities, structures and
their contents. Refer to FEMA Technical Bulletins TB-1 (Openings in
Foundation Walls and Walls of Enclosures, 2008), TB-3 (Non-residential
Floodproofing – Requirements and Certification, 1993), and TB-7(Wet
Floodproofing Requirements, 1993) for Guidelines on dry and wet
floodproofing.
Floodway
The channel of a river or other watercourse and the adjacent land area that
must be reserved in order to discharge the base flood without cumulatively
increasing the water surface elevation. Also referred to a "Regulatory
Floodway."
Flood Insurance
Risk Zone
Designations
The zone designations indicating the magnitude of the flood
hazard in specific areas of a community. See Special Flood Hazard Area.
Zone A
Special Flood Hazard Areas inundated by the 100-year flood; base
flood elevations are not determined.
Zone A1-30
and Zone AE
Special Flood Hazard Areas inundated by the 100-year
flood; base flood elevations are determined.
Zone AO
Special Flood Hazard Areas inundated by the 100-year flood; with
flood depths of 1 to 3 feet (usually sheet flow on sloping terrain);
average depths are determined. For areas of alluvial fan flooding,
velocities are also determined.
Zone AH
Special Flood Hazard Areas inundated by the 100-year flood; flood
depths of 1 to 3 feet (usually areas of ponding); base flood
elevations are determined.
Zone AR
Special Flood Hazard Areas that result from the decertification of a
previously accredited flood protection system that is in the process
of being restored to provide a 100-year or greater level of flood
protection.
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Zones AR / A1-30,
AR / AE, AR / AH,
AR / AO, and
AR / A
Special Flood Hazard Areas that result from the
decertification of a previously accredited flood protection
system that is in the process of being restored to provide a
100-year or greater level of flood protection. After restoration is
complete, these areas will still experience residual flooding from
other flooding sources.
Zone A99
Special Flood Hazard Areas inundated by the 100-year flood to be
protected from the 100-year flood by a Federal flood protection
system under construction; no base flood elevations determined.
Zone B and
Zone X (shaded)
Areas of 500-year flood; areas subject to the 100-year flood
with average depths of less than 1 foot or with contributing drainage
area less than 1 square mile; and areas protected by levees from the
base flood.
Zone C and
Areas determined to be outside the 500-year floodplain.
Zone X (unshaded)
Zone D
Areas in which flood hazards are undetermined.
Footing
The enlarged base of a foundation wall, pier, or column, designed to spread
the load of the structure so that it does not exceed the soil bearing capacity.
Foundation
The underlying structure of a building usually constructed of concrete that
supports the foundation walls, piers, or columns.
Foundation Walls
A support structure that connects the foundation to the main portion of the
building or superstructure.
Fraud/
Victimization
Related to Variances of this ordinance, the variance granted must
not cause fraud on or victimization to the public. In examining this
requirement, the {community, governing body} will consider the fact that
every newly constructed building adds to government responsibilities, and
remains a part of the community for fifty to one hundred years. Buildings
permitted to be constructed below the base flood elevation are subject
during all those years to increased risk of damage from floods, while future
owners of the property and the community as a whole are subject to all the
costs, inconvenience, danger, and suffering that those increased flood
damages bring. Additionally future owners may be unaware of the risk
potential to the property due to flood damage and the extremely high rates
for flood insurance.
Freeboard
A margin of safety usually expressed in feet above a flood level for
purposes of flood plain management. Freeboard tends to compensate for the
many unknown factors that could contribute to flood heights greater than
the height calculated for selected size flood and floodway conditions, such
as wave action, bridge openings, and the hydrological effect of urbanization
of the watershed.
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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
marina facilities, port facilities that are necessary for the loading and
unloading of cargo or passengers, and boat building and boat repair
facilities, but does not include long-term storage or related manufacturing
facilities.
Governing Body
The local governing unit, county or municipality that is empowered to adopt
and implement regulations to provide for public health, safety and general
welfare of its citizenry.
Hardship
Related to Variances of this ordinance. The exceptional hardship would
result from a failure to grant the requested variance. The {governing body}
requires the variance be exceptional, unusual, and pertain only to the
property involved. Mere economic or financial hardship alone is not
exceptional. Inconvenience, aesthetic considerations, physical handicaps,
personal preferences, or the disapproval of one's neighbors likewise cannot,
as a rule, qualify as an exceptional hardship. All of these problems can be
resolved through other means without granting a variance, even if the
alternative is more expensive, or requires the property owner to build
elsewhere or put the parcel to a different use than originally intended.
Highest Adjacent
Grade
The highest natural elevation of ground surface prior to construction next
to the proposed walls of a structure.
Historic Structure
Any structure that is:
Hydraulics
1.
Listed individually in the National Register of Historic Places (a
listing maintained by the Department of 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 Interior; or
4.
Individually listed on a local inventory of historic places in
communities with historic preservation programs that have been
certified either by an approved State program as determined by the
Secretary of the Interior or directly by the Secretary of the Interior in
states without approved programs.
The science that deals with practical applications of water in motion.
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Hydrodynamic
Loads
Forces imposed on structures by floodwaters due to the impact of
moving water on the upstream side of the structure, drag along its sides, and
eddies or negative pressures on its downstream side.
Hydrology
The science of the behavior of water in the atmosphere, on the earth's
surface and underground.
Hydrostatic
Loads
Forces imposed on a flooded structure due to the weight of the
water.
Letter of Map
Amendment
(LOMA)
The procedure by which any owner or lessee of property who
believes his property has been inadvertently included in a Special
Flood Hazard Area can submit scientific and technical information to the
Federal Insurance Administrator for review to remove the property from
said area. The Administrator will not consider a LOMA if the information
submitted is based on alteration of topography or new hydrologic or
hydraulic conditions since the effective date of the FIRM.
Letter of Map
Revision (LOMR)
An official revision to a currently effective FIRM. A LOMR
officially changes flood zone, floodplain and floodway designations, flood
elevations and planimetric features.
Letter of Map
A letter from FEMA stating that an existing structure or parcel of
Revision (Based
land that has been elevated by fill would not be inundated by the
On Fill) (LOMR-F) base flood.
Levee
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
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 the enclosure does
not violate applicable non-elevation design requirements.
Manufactured
Home (mobile
home)
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 attached to the required utilities. The term
"manufactured home" does not include "recreational vehicles”.
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Manufactured
Home Park or
Subdivision
A parcel or contiguous parcels of land divided into two or more
manufactured home lots for rent or sale.
Market Value
For the purposes of determining substantial improvement, market value
pertains only to the structure in question. It does not pertain to the land,
landscaping or detached accessory structures on the property. For
determining improvement, the value of the land must always be subtracted.
Acceptable estimates of market value can be obtained from the following
sources:
1.
Independent appraisals by a professional appraiser.
2.
Detailed estimates of the structure's Actual Cash Value (used as a
substitute for market value based on the preference of the
community).
3.
Property appraisals used for tax assessment purposes (Adjusted
Assessed Value: used as a screening tool).
4.
The value of buildings taken from NFIP claims data (used as a
screening tool).
5.
"Qualified estimates" based on sound professional judgment made
by staff of the local building department or local or State tax
assessor's office.
As indicated above, some market value estimates should only be used as
screening tools to identify those structures where the substantial
improvement ratios are obviously less than or greater than 50% (e.g., less
than 40% or greater than 60%). For structures that fall between the 40%
and 60% range, more precise market value estimates should be used.
Mobile Home
Having the same meaning as manufactured home.
North American
Vertical Datum
(NAVD)
A vertical control used as a reference for establishing various elevations
within the floodplain based upon the General Adjustment of the North
American Datum of 1988. Flood elevations on Digital Flood Insurance
Rate Maps for Nevada communities are referenced to NAVD 88.
National Geodetic
Vertical Datum
(NGVD)
As corrected in 1929, is a vertical control used as a reference for
establishing various elevations within the floodplain. Flood elevations on
Flood Insurance Rate Maps published for Nevada communities prior to
2007 were typically referenced to NGVD 29.
Natural Grade
The grade unaffected by construction techniques such as fill, landscaping,
or berming.
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New Construction
Buildings 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, including any subsequent improvements.
New Manufactured A manufactured home park or subdivision for which the
Home (mobile home) construction of construction of facilities for servicing the lots on
Subdivision
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 these floodplain management regulation adopted by
{community or governing body}.
Non-Residential
Includes, but is not limited to: small business concerns, churches, schools,
farm buildings (including grain bins and silos), poolhouses, clubhouses,
recreational buildings, mercantile structures, agricultural and industrial
structures, warehouses, and hotels or motels with normal room rentals for
less than 6 months duration.
Obstruction
Includes, but is not limited to, any dam, wall, wharf, embankment, levee,
dike, pile, abutment, protection, excavation, channelization, bridge, conduit,
culvert, building, wire, fence, rock, gravel refuse, fill, structure, vegetation
or other material in, along, across or projecting into any watercourse which
may alter, impede, retard or change the direction and or velocity of the flow
of water, or due to its location, its propensity to snare or collect debris
carried by the flow of water, or its likelihood of being carried downstream.
One-Hundred
Year-flood
Having the same meaning as base flood.
Physical Map
Revisions (PMR)
A reprinted NFIP map incorporating changes to floodplains,
floodways, or flood elevations. Because of the time and cost involved to
change, reprint, and redistribute an NFIP map, a PMR is usually processed
when a revision reflects large scope changes.
Ponding Hazard
A flood hazard that occurs in flat areas when there are depressions in the
ground that collect “ponds” of water. The ponding hazard is represented by
the zone designation AH on the FIRM.
Post-FIRM
Construction
Construction or substantial improvement that started on or after the
effective date of the initial Flood Insurance Rate Map (FIRM) of the
community or after December 31, 1974, whichever is later.
Pre-FIRM
Construction
Construction or substantial improvement which started on or
before December 31, 1974 or before the effective date of the initial Flood
Insurance Rate Map (FIRM) of the community, whichever is later.
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Principal Residence A single family dwelling in which at the time of loss, the named insured or
the named insured’s spouse has lived for either (1) 80 percent of the
calendar year, or (2) 80 percent of the period of ownership, if less than 1
year.
Principal Structure A structure used for the principal use of the property as distinguished from
an accessory use.
Program Deficiency A defect in a community’s floodplain management regulations or
administrative procedures that impairs effective implementation of those
floodplain management regulations.
Proper Openings
For Enclosures
(Applicable to
Zones A, A1-A30,
AE, AO, AH, AR,
and AR Dual)
All enclosures below the lowest floor must be designed to
automatically equalize hydrostatic flood forces on exterior walls by
allowing for the entry and exit of floodwaters. A minimum of two
openings, with positioning on at least two walls, having a total net
area of not less than 1 square inch for every square foot of
enclosed area subject to flooding must be provided. The
Public Safety/
Nuisance
Related to Variances of the ordinance. The granting of a variance
must not result in anything which is injurious to safety or health of the
entire community or neighborhood, or any number of persons, or
unlawfully obstructs the free passage or use, in the customary manner, of
any navigable lake, or river, bay stream, canal, or basin.
Recreational
Vehicle
A vehicle built on a single chassis, 400 square feet or less when
measured at the largest horizontal projection, designed to be self-propelled
or permanently towable by a light-duty track, and designed primarily not for
use as a permanent dwelling but as temporary living quarters for
recreational, camping, travel, or seasonal use.
Riverine
Relating to, formed by, or resembling a river including tributaries, stream,
brook, etc.
Sheet Flow Area
Having the same meaning as Area of Shallow Flooding.
Special Flood
Hazard Area
(SFHA)
Darkly shaded area on a Flood Hazard Boundary Map (FHBM) or
a Flood Insurance Rate Map (FIRM) that identifies an area that has
a 1- percent chance of being flooded in any given year (100-year
floodplain). Over a 30-year period, the life of most mortgages, there is at
least a 26 percent chance that this area will be flooded. The FIRM
identifies these shaded areas as FIRM Zones A, AO, AH, A1-A30, AE,
A99, AR, AR/A, AR/AE, AR/A1-A30, AR/AH, AR/AO, V, V1-V30, and
VE. See Flood Insurance Risk Zone Designations.
Start of
Construction
Includes substantial improvement and other proposed new
development 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 from the
13
date of the permit. 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 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.
Structure
A walled and roofed building that is principally above ground and includes
gas or liquid storage tanks and manufactured homes.
Substantial
Damage
Damage of any origin sustained by a structure whereby the cost of
restoring the structure to its before damage condition would equal or exceed
50 percent of the market value of the structure before the damage occurred.
Substantial
Improvement
Any reconstruction, rehabilitation, addition, or other proposed new
development of a structure, the cost of which equals or exceeds 50 percent
of the market value of the structure before the "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
a 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
A grant of relief from the requirements of this ordinance which permits
construction in a manner that would otherwise be prohibited by this
ordinance.
Violation
The failure of a structure or other development to be fully compliant with
this ordinance. A structure or other development in a special flood hazard
area, without an elevation certificate, other certifications or other evidence
of compliance required in this ordinance is presumed to be in violation until
such time as that documentation is provided.
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Water Surface
Elevation
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.
Watercourse
A lake, river, creek, stream, wash, arroyo, channel or other topographic
feature on or over which waters flow at least periodically. Watercourse
includes specifically designated areas in which substantial flood damage
may occur.
15
SECTION 3
GENERAL PROVISIONS
3.1
LANDS TO WHICH THIS ORDINANCE APPLIES
This ordinance shall apply to all areas of special flood hazards within the jurisdiction of
county or municipality.
3.2
BASIS FOR ESTABLISHING AREAS OF SPECIAL FLOOD HAZARD
The areas of special flood hazard identified by the Federal Insurance Administration (FIA)
of the Federal Emergency Management Agency (FEMA) in the Flood Insurance Study
(FIS) dated date and accompanying Flood Insurance Rate Maps (FIRM) and Flood
Boundary and Floodway Maps (FBFM), dated date, and all subsequent amendments and
or revisions, are hereby adopted by reference and declared to be a part of the ordinance.
The FIS and attendant mapping is the minimum area of applicability of this ordinance and
may be supplemented by studies for other areas which allow implementation of this
ordinance and which are recommended to the governing body by the Floodplain
Administrator. The FIS, FIRMs and FBFMs are on file at address, City Hall, County
Administration Building, Department of Public Works, or other.
3.3
COMPLIANCE
No structure or land shall hereafter be constructed, located, extended, converted, or altered
without full compliance with the terms of this ordinance and other applicable regulations.
Violations (including violations of conditions and safeguards established in connection
with conditions) shall constitute a {type of offense}. Nothing herein shall prevent the
{governing body} from taking such lawful action as is necessary to prevent or remedy any
violation.
3.4
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 other ordinances,
easement, covenant, or deed restriction conflict or overlap, whichever imposed the more
stringent restrictions or that imposing the higher standards, shall prevail.
3.5
INTERPRETATION
The interpretation and application of this ordinance, all provisions shall be:
C.
A.
Considered as minimum requirements;
B.
Liberally construed in favor of the governing body; and
Deemed neither to limit nor repeal any other powers granted under state statutes.
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3.6
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. Larger
floods can and will occur on rare occasions. 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 within such areas will be free from flooding or flood damages.
This ordinance shall not create liability on the part of {governing body}, any officer or
employee thereof, the State of Nevada, or the Federal Insurance Administration, Federal
Emergency Management Agency, for any flood damages that result from reliance on this
ordinance or any administrative decision lawfully made hereunder.
3.7
DECLARATION OF PUBLIC NUISANCE.
Every new structure, building, fill, excavation or development located or maintained
within any area of special flood hazard after {date of first FIRM} in violation of this
ordinance is a public nuisance per se and may be abated, prevented or restrained by action
of this political subdivision.
3.8
ABATEMENT OF VIOLATIONS
Within 30 days of discovery of a violation of this ordinance, the Floodplain Administrator
shall submit a report to the {governing body} which shall include all information available
to the Floodplain Administrator which is pertinent to said violation. Within 30 days of
receipt of this report, the {governing body} shall either:
3.9
A.
Take any necessary action to effect the abatement of such violation; or
B.
Issue a variance to this ordinance in accordance with the provisions of Section 6.0
(Variance Procedures) herein; or
C.
Order the owner of the property upon which the violation exists to provide
whatever additional information may be required for their determination. Such
information must be provided to the {administering body} within 30 days of such
order, and he shall submit an amended report to the Floodplain board with 20 days.
At their next regularly scheduled public meeting, the governing body shall either
order the abatement of said violation or they shall grant a variance in accordance
with the provisions of Section 6.0 (Variance Procedures) herein.
D.
Submit to the Administrator of Federal Insurance Administration a declaration for
denial of insurance, stating that the property is in violation of a cited statute or local
law, regulation or ordinance, pursuant to section 1316 of the National Flood
Insurance Act of 1968 as amended.
UNLAWFUL ACTS
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A.
It is unlawful for any person to divert, retard or obstruct the flow of waters in any
watercourse whenever it creates a hazard to life or property without securing the
written authorization of the {administering body}. Where the watercourse is a
delineated floodplain, it is unlawful to excavate or build any structure affecting the
flow of waters without securing written authorization of the Floodplain
Administrator.
B.
Any person violating the provisions of this section shall be guilty of a class 2
misdemeanor.
3.10 SEVERABILITY
This ordinance and the various parts thereof are hereby declared to be severable. Should
any section of this ordinance be declared by the courts to be unconstitutional or invalid,
such decisions shall not affect the validity of the ordinance as a whole, or any portion
thereof other than the section so declared to be unconstitutional or invalid.
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SECTION 4
ADMINISTRATION
4.1
DESIGNATION OF THE LOCAL FLOODPLAIN ADMINISTRATOR
{Name of administrator and title} is here by appointed Local Floodplain Administrator to
administer and implement this local ordinance by granting or denying floodplain
development permits in accordance with its provisions.
4.2
ESTABLISHMENT OF DEVELOPMENT PERMIT
A floodplain development permit is hereby established for all construction and other
development to be undertaken in areas of special flood hazard in {county or municipality}
for the purpose of protecting its citizens from increased flood hazards and ensuring new
development is constructed in a manner that minimizes its exposure to flooding. It shall be
unlawful to undertake any development in an area of special flood hazard, as shown on the
Flood Insurance Rate Map enumerated in Sub-section 3.2 (Basis for Establishing Areas of
Special Flood Hazard), without a valid floodplain development permit. Applications for a
permit shall be made on forms furnished by the Local Floodplain Administrator and may
include, but not be limited to: plans in duplicate drawn to scale showing the nature,
location, dimensions, and elevation of the area in question, existing or proposed structures,
fill, storage of materials, drainage facilities, and the location of the foregoing.
4.3
PERMIT APPLICATION
The applicant shall provide at least the following information, where applicable.
Additional information may be required on the permit application forms.
A.
The proposed elevation in relation to mean sea level, of the lowest floor (including
basement) of all residential and non-residential structures whether new or
substantially improved to be located in Zones A, Al-A30, AE, and AH, if base
flood elevations data are available.
B.
In Zone AO the proposed elevation in relation to mean sea level, of the lowest floor
(including basement) and the elevation of the highest adjacent grade of all
residential and nonresidential structures whether new or substantially improved.
C.
The proposed elevation in relation to mean sea level, to which any new or
substantially improved non-residential structure will be floodproofed.
D.
A certificate from a licensed professional engineer or architect in the State of
Nevada that any utility floodproofing meets the criteria in Sub-section 5.2
(Standards for Utilities).
E.
A certificate from a licensed professional engineer or architect in the State of
Nevada that any non-residential floodproofed structures meet the criteria in Subsection 5.1.5 (Nonresidential Floodproofing Requirements).
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4.4
F.
When a watercourse will be altered or relocated as a result of the proposed
development, the applicant must submit the maps, computations, and other
materials required by the Federal Emergency Management Agency (FEMA) to
process a Letter of Map Revision (LOMR) and pay any fees or other costs assessed
by FEMA for processing the revision.
G.
A technical analysis, by a professional engineer licensed in the State of Nevada,
showing the proposed development located in the special flood hazard area will not
cause physical damage to any other property.
H.
When there is no base flood elevation data available for Zone A from any source,
the base flood elevation data will be provided by the permit applicant for all
proposed development of subdivisions, manufactured home and recreational
vehicle parks in the special flood hazard areas, for all developments of 50 lots or 5
acres, whichever is less.
DUTIES AND RESPONSIBILITIES OFTHE LOCAL FLOODPLAIN
ADMINISTRATOR
Duties and responsibilities of the Local Floodplain Administrator shall include, but not
limited to the following:
4.4.1 PERMIT APPLICATION REVIEW
The floodplain development permit will not be issued by the Local Floodplain
Administrator until the following has been accomplished:
A.
Review all applications for completeness, particularly with the requirements of
Sub-section 4.3 (Permit Application), and for compliance with the provisions and
standards of this ordinance.
B.
Review all subdivision and other proposed new development, including
manufactured home and recreational vehicle parks to determine whether the
proposed development site will be reasonably safe from flooding. When the
proposed building site is located in the Special Flood Hazard Area, all new
construction and substantial improvements will meet the applicable standards of
Sub-section 5.1 (Standards of Construction).
C.
Determine whether any proposed development in the Special Flood Hazard Area
may result in physical damage to any other property to include stream bank erosion
and any increase in velocities or that it does not adversely affect the carrying
capacity of the areas where base flood elevations have been determined but a
floodway has not been designated. For purposes of the ordinance, "adversely
affects" means the cumulative effect of the proposed development when combined
with all other existing and anticipated development will increase the water surface
elevation of the base flood more than one foot at any point. To assist the Local
20
Floodplain Administrator in making this determination, the permit applicant may
be required to submit additional technical analyses.
D.
Ensure all other required State and Federal permits have been received.
E.
For construction on an existing structure, determine if proposed construction
constitutes substantial improvement or repair of a substantially damaged structure.
4.4.2 USE OF OTHER FLOOD DATA
A.
When the Federal Emergency Management Agency has designated Special Flood
Hazard Areas on the community's Flood Insurance Rate Maps (FIRM) but has
neither produced water surface elevation data nor identified a floodway, the Local
Floodplain Administrator shall attempt to obtain, review and reasonably utilize any
base flood elevation and floodway data available from a Federal, State or other
source, including data developed pursuant to Paragraph 4.4.6.I (Retaining
Floodplain Development Documentation), as criteria for requiring new
construction, substantial improvements or other proposed development meets the
requirements of this ordinance.
B.
When base flood elevations are not available, the Local Floodplain Administrator
may use flood information from any other authoritative source, such as historical
data, to establish flood elevations within the Special Flood Hazard Areas. This
information shall be submitted to the governing body} for adoption.
4.4.3 ALTERATION OF WATERCOURSES
Prior to issuing a permit for any alteration or relocation of watercourse the Local
Floodplain Administrator must:
A.
Have processed Letter of Map Revision (LOMR).
B.
Notify all adjacent communities, Nevada's National Flood Insurance Program
Coordinator, and submittal of evidence of such notification to the Federal Insurance
Administration, and the Federal Emergency Management Agency.
C.
Determine that the potential permit recipient has provided for maintenance within
the altered or relocated portion of said watercourse so that the flood carrying
capacity is not diminished.
4.4.4 INSPECTIONS
The Local Floodplain Administrator or designee shall make periodic inspections
throughout the period of construction to monitor compliance with the requirements of the
floodplain development permit or any variance provisions.
4.4.5 STOP WORK ORDERS
21
The Local Floodplain Administrator shall issue, or cause to be issued, a stop work for any
floodplain development found non-compliant with the provisions of this ordinance or
conditions of the development permit and all development found ongoing without a
floodplain development permit. Disregard of a stop work order shall subject the violator to
the penalties described in Sub-section 3.3 (Compliance) of this ordinance.
4.4.6 RETAINING FLOODPLAIN DEVELOPMENT DOCUMENTATION
The Local Floodplain Administrator shall obtain and retain for public inspection and have
available for the National Flood Insurance Program coordinator or the Federal Emergency
Management Agency representative conducting a Community Assistance Visit, the
following:
A.
Floodplain development permits and certificates of compliance.
B.
Elevation Certificates with record of certification required by Sub-section 5.1.4
(Lowest Floor Certification Requirements).
C.
Certifications required by Sub-section 5.1.5(Nonresidential Floodproofing
Requirements).
D.
Elevation Certificates with record of certification required by Sub-section 5.1.6
(Requirements for Areas Below the Lowest Floor)
E.
Elevation Certificates with record of certification of elevation required by Subsection 5.3 (Standards for Subdivisions).
F.
Certification required by Sub-section 5.7 (Floodways)
G.
Variances issued pursuant to Section 6.0 (Variance Procedures).
H.
Notices required under Sub-section 4.4.3 (Alteration of Watercourses).
4.4.7 MAP DETERMINATIONS
The Local Floodplain Administrator may make map interpretations where needed, in
writing with appropriate documentation, as to the exact location of the boundaries of the
areas of special flood hazard and where there appears to be a conflict between a mapped
boundary and actual field conditions.
4.4.8 APPEALS
The {governing body} of {county or municipality} shall hear and decide appeals 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.
22
4.4.9 SUBMISSION OF NEW TECHNICAL DATA TO FEMA
When {community or municipality} base flood elevations either increase or decrease
resulting from physical changes affecting flooding conditions, as soon as practicable, but
not later than six months after the date such information becomes available, {community or
municipality} will submit the technical or scientific data to FEMA. Such submissions are
necessary so that upon confirmation of the physical changes affecting flooding conditions,
risk premium rates and flood plain management requirements will be based upon current
data.
23
SECTION 5
PROVISIONS FOR FLOOD HAZARD REDUCTION
5.1
STANDARDS OF CONSTRUCTION
In all areas of special flood hazard areas the following standards are required.
5.1.1 ANCHORING
A.
All new construction and substantial improvements shall be adequately anchored to
prevent flotation, collapse or lateral movement of the structure resulting from
hydrodynamic and hydrostatic loads, including the effects of buoyancy.
B.
All manufactured homes shall meet the anchoring standards of Sub-section 5.5
(Standards for Manufactured Homes).
5.1.2 CONSTRUCTION MATERIALS AND METHODS
All new construction and substantial improvements shall be constructed;
A.
With materials and utility equipment resistant to flood damage;
B.
Using methods and practices that minimize flood damage;
C.
Ensure electrical, heating, ventilation, plumbing, air conditioning equipment and
other service facilities are designed or located so as to prevent water from entering
or accumulating within the components during conditions of flooding;
D.
Within Zones AH or AO, so that there are adequate drainage paths around
structures on slopes to guide flood waters around and away from proposed
structures.
5.1.3 ELEVATION REQUIREMENTS FOR LOWEST FLOOR
Residential construction, new or substantial improvements, shall have the lowest floor,
including basement;
A.
In Zone AO, elevated above the highest adjacent grade to a height equal to or
exceeding the depth number specified in feet on the FIRM, or elevated at least two
feet above the highest adjacent grade if no depth number is specified.
B.
In Zone A, elevated to or above the base flood elevation, as determined by this
community.
C.
In all other zones, elevated to or above the base flood elevation.
5.1.4 LOWEST FLOOR CERTIFICATION REQUIREMENTS
24
Upon completion of the structure, the elevation of the lowest floor including basement
shall be certified by a registered professional engineer or surveyor and verified by the
community building inspector to be properly elevated. The certification shall be provided
to the Floodplain Administrator using the current FEMA Elevation Certificate.
5.1.5 NONRESIDENTIAL FLOODPROOFING REQUIREMENTS
Nonresidential construction shall either be elevated to conform with Sub-section 5.1.3
(Elevation Requirements for Lowest Floor) or together with attendant utility and sanitary
facilities;
A.
Will be floodproofed below the elevation recommended under Sub-section 5.1.3
(Elevation Requirements for Lowest Floor) so that the structure is watertight with
walls substantially impermeable to the passage of water:
D.
Will have the structural components capable of resisting hydrostatic and
hydrodynamic loads and effects of buoyancy:
C.
Will be certified by a registered professional engineer or architect that the standards
of Sub-section 5.1.3 (Elevation Requirements for Lowest Floor) are satisfied. The
certification shall be provided to the Floodplain Administrator.
5.1.6 REQUIREMENTS FOR AREAS BELOW THE LOWEST FLOOR
All new construction and substantial improvements with fully enclosed areas below the
lowest floor (excluding basements) that are usable solely for parking of vehicles, building
access or storage, and which are subject to flooding, shall be designed to automatically
equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of
floodwaters. Designs for meeting this requirement shall follow the guidelines in FEMA
Technical Bulletins TB-1 (Openings in Foundation Walls and Walls of Enclosures, 2008)
and TB-7 (Wet Floodproofing Requirements, 1993) and must either be certified by a
licensed professional engineer or architect to meet or exceed the following minimum
criteria;
A.
Must have a minimum of two openings having a total net area of not less than one
square inch for every square foot of enclosed area subject to flooding;
B.
The bottom of all such openings will be no higher than one foot above the lowest
adjacent finished grade.
Openings may be equipped with louvers, valves, screens or other coverings or devices
provided they permit the automatic entry and exit of floodwaters.
5.2
STANDARDS FOR UTILITIES
A.
All new and replacement water supply systems shall be designed to minimize or
eliminate infiltration of floodwaters into the system.
25
5.3
B.
All new and replacement sanitary sewage systems shall be designed to minimize or
eliminate infiltration of flood waters or discharge from the systems into flood
waters. Sanitary sewer and storm drainage systems for buildings that have
openings below the base flood elevation shall be provided with automatic backflow
valves or other automatic backflow devices that are installed in each discharge line
passing through a building's exterior wall.
C.
On-site waste disposal systems shall be located to avoid impairment to them or
contamination from them during flooding.
STANDARDS FOR SUBDIVISIONS
A.
All preliminary subdivision proposals shall identify the flood hazard area and the
elevation of the base flood.
D.
All subdivision plans will provide the elevation of proposed structures and pads. If
the site is filled above the base flood, the final lowest floor and pad elevation shall
be certified by a registered professional engineer or surveyor and provided to the
Floodplain Administrator.
E.
All subdivision proposals shall be consistent with the need to minimize flood
damage.
All subdivision proposals shall have public utilities and facilities such as sewer,
gas, electrical and water systems located and constructed to minimize flood
damage.
D.
E.
All subdivisions shall provide adequate drainage to reduce exposure to flood
hazards.
F.
Additionally all subdivision proposals will demonstrate, by providing a detailed
hydrologic and hydraulic analyses that 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
5.2.1 STANDARDS FOR CRITICAL STRUCTURES
Critical structures are not authorized in a Special Flood Hazard Area, unless:
A.
All alternative locations in Flood Zone X have been considered and rejected.
B.
All alternative locations in Flood Zone Shaded X have been considered and
rejected.
If the floodplain manager determines the only practical alternative location for the
development of a new or substantially improved critical structure is in a Special Flood
Hazard Area he must:
26
A.
5.5
Give public notice of the decision and reasons for the elimination of all alternative
locations.
STANDARDS FOR MANUFACTURED HOMES
A.
All manufactured homes that are placed or substantially improved, within Zones A,
AH, AE, and on the community's Flood Insurance Rate Map, on sites located:
1.
Outside of a manufactured home park or subdivision;
2.
In a new manufactured home park or subdivision;
3.
In an expansion to an existing manufactured home park or subdivision; or
4.
In an existing manufactured home park or subdivision on a site upon which
a manufactured home has incurred "substantial damage" as a result of a
flood:
a.
B.
Shall be elevated on a permanent foundation so that the lowest floor
will be elevated to or above the base flood elevation and be securely
anchored to an adequately anchored foundation system to resist
flotation, collapse and lateral movement. Methods of anchoring may
include, but are not to 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.
All manufactured homes to be placed or substantially improved on sites in an
existing manufactured home park or subdivision within Zones A, AH, and AE on
the community's Flood Insurance Rate Map that are not subject to the provisions of
Sub-section 5.4 (Standards for Critical Structures) will be elevated so that either
the:
1.
The bottom of structural frame or the lowest point of the manufactured
home is at or above the base flood elevation; or
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 securely anchored to an adequately
anchored foundation system to resist flotation, collapse, and lateral
movement.
C.
Within Zone A, when no base flood elevation data is available, new and
substantially improved manufactured homes shall have the floor elevated at least
three feet above the highest adjacent grade.
G.
Within Zone AO, the floor for all new and substantially improved manufactured
homes will be elevated above the highest adjacent grade at least as high as the
depth number specified on the Flood Insurance Rate Map, or at least two feet if no
27
depth number is specified. Upon the completion of the structure, the elevation of
the lowest floor including basement shall be certified by a registered professional.
5.6
STANDARDS FOR RECREATIONAL VEHICLES
All recreational vehicles placed on sites within the floodplain on the community's Flood
Insurance Rate Map will either;
5.7
A.
Be on the site for fewer than 180 consecutive days;
B.
Be fully licensed and ready for highway use. 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, or:
C.
Will meet the permit requirements of Sub-section 4.3 (Permit Application) and the
elevation and anchoring requirements for manufactured homes in Sub-section 5.5
(Standards for Manufactured Homes).
FLOODWAYS
Since the floodway is an extremely hazardous area due to the velocity of floodwaters,
which carry debris, potential projectiles, and erosion potential, the following provisions
apply.
A. If a floodway has not been designated within the special flood hazard areas established
in Sub-section 3.2 (Basis for Establishing Areas of Special Flood Hazard), no new
construction, substantial improvement, or other development (including fill) shall be
permitted within Zones A1-30 and AE, unless it has been 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.
B. In designated floodways located within the special flood hazard areas established in
Sub-section 3.2 (Basis for Establishing Areas of Special Flood Hazard) encroachment
shall be prohibited, including fill, new construction, substantial improvements,
