HomeMy WebLinkAboutOrdinance 91- 1334, Flood hazard district, zoning
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ORDINANCE NO. 1334
AN ORDINANCE OF THE CITY COMMISSION OF THE CITY OF
BOZEMAN, MONTANA, ADOPTING REGULATIONS IN COMPLIANCE
WITH THE MONTANA FLOODPLAIN AND FLOODWAY MANAGEMENT
ACT.
Preamble
Pursuant to the authority found in Sections 76-5-101 through
76-5-406 and Section 7-1-4123, Montana Code An notated, this
ordinance is passed to promote public health, safety and welfare
by requiring compliance with the Montana Floodplain and Floodway
Management Act to ensure compliance with the requirements for
continued participation of the City of Bozeman in the National
Flood I nsurance Program,
NOW, THEREFORE, BE IT ORDAI NED by the City Commission of the
City of Bozeman, Montana as follows.
Section 1
Intent
This ordinance is passed in order to comply with the Montana Floodplain
and Floodway Management Act (Title 76, Chapter 5, Montana Code Annotated)
and to ensure compliance with the requirements for the continued participation
by the City of Bozeman, Gallatin County, Montana, in the National Flood I nsur-
ance Program. Land use regulations which are hereby adopted as Exhibit "A"
are to be appl ied to all identified 100-year floodplains within the City of
Bozeman's zoning jurisdictional area.
Section 2
Adoption
This ordinance adopts the set of comprehensive land use regulations, at-
tached hereto as Exhibit "A," and by this reference made a part hereof as if
fully set forth herein, for identified 100-year floodplains within the City of
Bozeman, Gallatin County, Montana, Identification of the 100-year floodplains is
based on the Flood Plain Management Study for the City of Bozeman, Gallatin
County, Montana, dated July 15, 1998,
Section 3
Savings Provision
This ordinance does not affect rights and duties that matured, penalties
that were incurred or proceedings that were begun before the effective date of
this ordinance,
Section 4
Severability
If any provision of this ordinance is declared unconstitutional, or the
applicability thereof to any person or circumstance is held invalid, the con-
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stitutionality of the remainder of the ordinance and applicability thereof to other
persons and circumstances shall not be affected thereby.
Section 5
Repea ler
That any ordinances and parts of ordinances in conflict with the provi-
sions or this ordinance are hereby repealed,
PROVISIONALL Y PASSED AND ADOPTED by the City Commission of the
City of Bozeman at a regular session thereof held on the 16th day of September
1991.
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ATTEST:
~ itrL//~
R IN L. ULLlVAN
Clerk of the Commission
FI NALLY PASSED AND ADOPTED by the City Commission of the City of ,,-
II.
Bozeman at a regular session thereof held on the 30th day of September, 1991. .;
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ROBt, ~r
ATTEST:
(2~ sci~
Clerk of the Commission
APPROVED AS TO FORM:
BRUCE E, BECKER
City Attorney
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EXHIBIT "A"
FLOOD HAZARD DISTRICT
Seo1:ioD 1 Ti1:1e
These regulations shall be known and cited as the Bozeman
Area Floodplain Regulations. These regulations are in
accordance with exercising the authority of the laws of the
state of Montana.
section 2 Puroo..
To promote the public health, safety, and general welfare,
to minimize flood losses in areas subject to flood hazards,
and to promote wise use of the floodplain. These
regulations have been established with the following
purposes intended:
A. To guide development of the lOO-year floodplain within the
Bozeman Zoning Jurisdiction consistent with the enumerated
findings by:
1. Recognizing the right and need of water courses to
periodically carry more than the normal flow of water;
2. Participating in coordinated efforts of federal, state,
and local management activities for lOO-year
floodplains; and
3. Ensuring the regulations and minimum standards adopted,
insofar as possible, balance the greatest public good
with the least private injury.
B. Specifically it is the purpose of these regulations to:
1. Restrict or prohibit uses that are dangerous to health,
safety, and property in times of flood, or that cause
increased flood heights and velocities;
2. Require that uses vulnerable to floods, including
public facilities, be provided with flood protection at
the time of initial construction;
3. Identify lands unsuitable for certain development
purposes because of flood hazards;
4. Minimize the need for rescue and relief efforts
associated with flooding undertaken at the expense of
the general public;
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5. Ensure potential buyers are notified that property is
within a lOO-year floodplain and subject to the
provisions of these regulations; and
6. Ensure that those who occupy lOO-year floodplains
assume responsibility for their actions.
section 3 Definitions .
Unless specifically defined below, words or phrases used in
these regulations shall be interpreted to give them the
meaning they have in common usage and to give these
regulations the most reasonable application.
A. Act -- Montana Floodplain and Floodway Management Act, 176-
5-101 through 406, MeA.
B. Alteration -- Any change or addition to a structure that
either increases its external dimensions or increases its
potential flood hazard.
C. Aooeal -- A request for a review of the Floodplain
Administrator's interpretation of any provisions of these
regulations or a request for a variance.
D. Area of Soecial Flood Hazard -- The land in the floodplain
within the community subject to inundation by a one percent
(1%) or greater chance of flooding in any given year, i.e.,
the lOO-year floodplain.
E. Artificial Obstruction - Develooment -- Any obstruction
which is not natural and includes any dam, diversion, wall,
riprap, embankment, levee, dike, pile, abutment, projection,
revetment, excavation, channel rectification, bridge,
conduit, culvert, building, refuse, automobile body, fill,
or other analogous structure or matter in, along, across, or
projecting into any 100-year floodplain which may impede,
retard, or alter the pattern of flow of water, either in
itself or by catching or collecting debris carried by the
water, or that is placed where the natural flow of water
would carry the same downstream to the damage or detriment
. of either life or property.
F. Base Flood -- A flood having a one percent (1%) chance of
being equalled or exceeded in any given year. A base flood
is the same as a 100-year flood.
G. Base Flood Elevation -- The elevation above sea level of the
base flood in relation to National Geodetic Vertical Datum
of 1929 unless otherwise specified in the flood hazard
study.
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H. Channelization Proiect -- The excavation and/or construction
of an artificial channel for the purpose of diverting the
entire flow of a stream from its established course.
I. Establish -- To construct, place, insert, or excavate.
J. Existing Manufactured Home Park or Subdivision -- A
manufactured home park or subdivision where the construction
of facilities for servicing the manufactured homes lots is
completed before the effective date of the floodplain
management regulations. This includes, at a minimum, the
installation of utilities, the construction of streets, and
either final site grading or the pouring of concrete pads.
K. lEMA -- The Federal Emergency Management Agency
L. Flood or Floodinq -- A general and temporary condition of
partial or complete inundation of normally dry lands from
the overflow of a stream, or the unusual and rapid
accumulation or runoff of surface waters from any source.
M. Flood Insurance Rate MaD -- The map on which FEMA has
delineated both the 100 year floodplains and the risk
premium zones.
N. Flood Insurance studY -- The report in which FEMA has
provided flood profiles, as well as the Flood
Boundary/Floodway Map and the water surface profiles.
O. Floodplain -- The areas sUbject to these regulations,
generally adjoining a stream, that would be covered by
floodwater of a base flood except for designated shallow
flooding areas that receive less than one foot of water per
occurrence. The floodplain consists of a floodway and
floodway fringe.
P. Floodway -- The channel of a stream and the adjacent
overbank areas that must be reserved in order to discharge a
base flood without cumulatively increasing the water surface
elevation more than one-half (1/2) foot.
Q. Floodway Frinqe -- That portion of the floodplain outside
the limits of the floodway.
R. Levee -- A man-made embankment, usually earthen, designed
and constructed in accordance with sound engineering
practices to contain, control, or divert the flow of water
to provide protection from temporary flooding.
S. Levee Svstem'-- A flood protection system that consists of a
levee, or levees, and associated structures, such as
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drainage and closure devices, which are constructed and
operated in accordance with sound engineering practices.
T. Lowest Floor -- Any floor used for living purposes, storage,
or recreation. This includes any floor that could be
converted to such a use.
U. Manufactured Home -- A structure that is transportable in
one or more sections, built on a permanent chassis, and
designed to be used with or without a permanent foundation
when connected to the required utilities. This does not
include "recreational vehicles."
V. Manufactured Home Park or Subdivision -- A parcel or
contiguous parcels of land divided into two or more
manufactured home lots for rent or sale.
W. Mean Sea Level -- The National Geodetic vertical Datum
(NGVD) of 1929 or other datum to which base flood elevations
are referenced.
x. New Construction -- Structures for which construction,
substantial improvement, or alteration commences on or after
the effective date of these regulations.
Y. Official Flood~lain Mans -- The Flood Insurance Rate Maps
and Flood Boundary/Floodway Maps provided by FEMA for the
City of Bozeman, Montana, dated July 15, 1988.
Z. Permit Issuing Authoritv -- Bozeman city Commission.
AA. Recreational Vehicle -- A vehicle which is (1) built on a
single chassis; (2) 400 square feet or less when measured at
the largest horizontal projections; (3) d~signed to be self-
propelled or permanently towabl.e by a light duty truck; and
(4) designed primarily for use as temporary living quarters
for recreation, camping, travel, or seasonal use, not for
use as a permanent dwelling.
BB. Ripra~ -- Stone, rocks, concrete blocks, or analogous
material that is placed along the banks or bed of a stream
to alleviate erosion.
DO. Start of Construction -- Commencement of Clearing, grading,
filling, or excavating to prepare a site for construction.
EE. structure -- A walled and roofed building, manufactured
home, a gas or liquid storage tank, bridge, culvert, dam,
diversion, wall, revetment, dike, or other projection that
may impede, retard, or alter the pattern of flow of water.
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FF. Substantial Damaae -- Damage sustained by a structure where
the cost of restoring the structure to its condition before
damage would equal or exceed 50 percent of the market value
of the structure before the damage occurred.
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GG. Substantial Imorovement -- Any repair, reconstruction, or
improvement of a structure, the cost of which equals or
exceeds fifty percent (50%) of the market value of the
structure either:
(1) before the improvement or repair is started, or
(2) if the structure has been damaged, and is being
restored, before the damage occurred. For the purposes
of this definition, substantial improvement is
considered to occur when the first construction to any
wall, ceiling, floor, or other structural part of the
building commences. The term does not include:
(a) any project for improvement of a structure to
comply with existing state or local health,
sanitary, or safety code specifications which are
solely necessary to assure safe living conditions,
or
(b) any alteration of a structure listed on the
National Register of Historic Places or State
Inventory of Historic Places.
HH. suitable Fill -- Fill material which is stable, compacted,
well graded, pervious, generally unaffected by water and
frost, devoid of trash or similar foreign matter, devoid of
tree stumps or other organic material, and is fitting for
the purpose of supporting the intended use and/or permanent
structure.
II. variance -- A grant of relief f~om the requirements of
these regulations that would permit construction in a manner
otherwise prOhibited by these regulations.
JJ. violation -- The failure of a structure or other development
to be fully compliant with these regulations. A structure
or other development without elevation certificate,
certification by a licensed engineer or architect of
compliance with these regulations, or other evidence of
compliance is presumed to be in violation until such time as
documentation is provided.
KK. 100-Year Flood -- A flood having a one percent (1%) chance
of being equalled or exceeded in any given year. A 100-year
flood has nearly a 23 percent chance of occurring in a
25-year period. A 100-year flood is the same as a base
flood.
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Section 4 Jurisdictional Area
These regulations shall apply to all lands within the zoning
jurisdiction of the city of Bozeman, State of Montana, shown on
the Official Floodplain Maps as being located within a 100-year
floodplain district.
Section 5 Ploodolain District Establishment
The floodplain districts established are defined by the base
flood elevations and 100-year floodplains as delineated in the
Flood Insurance study. The basis for the Flood Insurance study
is a scientific and engineering report entitled "The Flood
Insurance study for the city of Bozeman, Montana", dated July 15,
1988, with accompanying Flood Insurance Rate Maps and Flood
Boundary/Floodway Maps. The Official Floodplain Maps, together
with the Flood Insurance study are on file in the office of the
Floodplain Administrator.
section , Ploodolain Administrator
The city of Bozeman Floodplain Administrator has been designated
to be the city Engineer. The responsibilities of this position
are outlined in Section 14 of these regulations.
section 7 Rules for InterDretation of PloodDlain District
Boundari..
The boundaries of the 100-year floodway shall be determined by
scaling distances on the official floodplain maps and using the
floodway data table contained in the flood insurance study
report. The maps may be used as a quide for determining the 100-
year floodplain boundary, but the exact location of the
floodplain boundary shall be determined where the base flood
elevation intersects the natural ground.
Section 8 Comoliance
No structure or land use shall be located, extended, converted,
or structurally altered without full compliance with the
provisions of these regulations and other applicable regulations.
These regulations meet the minimum floodplain development
requirements as set forth by the Montana Board of Natural
Resources and Conservation and the National Flood Insurance
Program.
section 9 Abroaation and Greater Resoonsibilitv
It is not intended by these regulations to repeal, abrogate, or
impair any existing easements, covenants, deed restrictions, or
underlying zoning. However, where these regulations impose
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greater restrictions, the provisions of these regulations shall
prevail.
Section 10 Reaulation InterDretation
The interpretation and application of the provisions of these
regulations shall be considered minimum requirements and
liberally construed in favor of the governing body and not deemed
a limitation or repeal of any other powers granted by St~te
statute.
Section 11 Warnina and Disclaimer of Liabilitv
These regUlations do not imply that areas outside the delineated
floodplain boundaries or permitted land uses will always be
totally free from flooding or flood damages. these regulations
shall not create a liability or cause of action against Bozeman,
Montana, or any officer or employee thereof for flood damages
that may result from reliance upon these regulations.
Section 12 Severability
If any section, clause, provision, or portion of these
regulations is adjudged unconstitutional or invalid by a court of
competent jurisdiction, the remainder of these regulations shall
not be affected thereby.
Section 13 Disclosure provision
All owners of property in an identified lOO-year floodplain as
indicated on the Official Floodplain Maps must notify potential
buyers or their agents that such property is subject to the
provisions of these regulations.
Section 14 Administration
A. As provided in Section 6 of these regulations, the
Floodplain Administrator has been designated by the city
Commission, and has the responsibility of such position as
outlined in these regulations.
B. The Floodplain Administrator is hereby appointed with the
authority to review floodplain development permit
applications, proposed uses, and construction to determine
compliance with these regulations. The Floodplain
Administrator is required to assure all necessary permits
have been received from those governmental agencies from
which approval is required by federal and state law and
local codes, including Section 404 of the Federal Water
Pollution Control Act of 1972, 33 U.S.C. 1334, and under the
provisions of the Natural streambed and Land Preservation
Act.
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1. Additional Factors -- Floodplain development permits
shall be granted or denied by the Floodplain
Administrator on the basis of whether the proposed
establishment, alteration, or substantial improvement
of an artificial obstruction meets the requirements of
these regulations. Additional factors that shall be
considered for every permit application are:
a. the danger to life and property due to increased
flood heights, increased flood water velocities,
or alterations in the pattern of flood flow caused
by encroachments;
b. the danger that materials may be swept onto other
lands or downstream to the injury of others;
c. the proposed water supply and sanitation systems
and the ability of these systems to prevent
disease, contamination, and unsanitary conditions;
d. the susceptibility of the proposed facility and
its contents to flood damage and the effects of
such damage on the individual owner;
e. the importance of the services provided by the
facility to the community;
f. the requirement of the facility for a waterfront
location;
g. the availability of alternative locations not
subject to flooding for the proposed use;
h. the compatibility of the proposed use with
existing development and anticipated development
in the foreseeable future;
i. the relationship of the proposed use to the
comprehensive plan and floodplain management
program for the area;
j .. the safety of access to property in times of
flooding for ordinary and emergency services; and
k. such other factors as are in harmony with the
purposes of these regulations, the Montana
Floodplain and Floodway Management Act, and the
National Flood Insurance Program.
C. A floodplain development permit application is considered to
have been automatically granted 60 days after the date of
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receipt of the application by the Floodplain Administrator
unless the applicant has been notified that the permit is
denied, conditionally approved, or additional information
pertinent to the permit review process is required.
D. The Floodplain Administrator shall adopt such administrative
procedures as may be necessary to efficiently administer the
provision of these regulations.
E. The Floodplain Administrator shall maintain such files and
records as may be necessary to document nonconforming uses,
base flood elevations, floodproofing and elevation
certifications, fee receipts, the issuance of permits,
agenda, minutes, records of public meetings, and any other
matters related to floodplain management in the Bozeman
Zoning Jurisdictional Area. Such files and records shall be
open for public inspection. In matters of litigation, the
City Attorney may restrict access to specific records.
F. The floodplain administrator may require whatever additional
information is necessary to determine whether the proposed
activity meets the reqirements of these regulations.
Additional information may include hydraulic calculations
assessing the impact on base flood elevations or velocities;
level survey; or certification by a registered land
surveyor, professional engineer, or licensed architect that
the requirements of these regulations are satisfied.
G. Upon receipt of an application for a permit or a variance,
the Floodplain Administrator shall prepare a notice
containing the facts pertinent to the application and shall
publish the notice at least once in a newspaper of general
circulation in the area. Notice shall also be served by
first-class mail upon adjacent property owners and the DNRC
Floodplain Management section. The notice shall provide a
reasonable period of time, not less than 15 days, for
interested parties to submit comments on the proposed
activity.
H. Copies of all permits granted must be sent to the Department
of Natural Resources and Conservation in Helena, Montana.
I. In riverine situations, notification by the Floodplain
Administrator must be made to adjacent communities, the
Floodplain Management Section (DNRC), and FEMA prior to any
alteration or relocation of a stream. The flood-carrying
capacity within the altered or relocated portion Of any
stream must be maintained. Erosion control measures shall
be incorporated to ensure stability of altered channels and
stream banks.
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SectioD 15 permit ADDlicatioDS
A. Activities or uses that require the issuance of a permit,
including the expansion or alteration of such uses, shall
not be initiated, established, or undertaken until a permit
has been issued by the Floodplain Administrator.
B. Permit applicants shall be required to furnish the following
information as deemed necessary by the Floodplain
Administrator for determining the suitability of the
particular site for the proposed use.
1. plans in duplicate drawn to scale (including
dimensions) showing the nature, location, and elevation
of the lot; existing and proposed structure locations;
fill, storage, or materials site; flood-proofing
measures; mean sea level elevation of first floor of
proposed structures; and location of the channel
and limits of 100-year floodplain boundary.
2. A plan view of the proposed development indicating
external dimensions of structures, street or road
finished grade elevations, well locations, individual
sewage treatment and disposal sites, excavation and/or
fill quantity estimates, and site plan and/or
construction plans.
3. Specifications for flood-proofing, filling, excavating,
grading, riprapping, storage of materials, and location
of utilities.
4. A professional engineer's or registered architect's
design calculations and certification that the proposed
activity has been designed to be in compliance with
these regulations.
5. certification of flood-proofing and/or elevation shall
be provided on a standard form available from the
floodplain administrator.
C. To determine that the permit specifications and conditions
have been completed, applicants who have received permits
are required to furnish the following at the time of an
on-site conformance inspection.
1. certification by a registered professional engineer or
licensed land surveyor of the actual mean sea level
elevation of the lowest floor (including basement) of
all new, altered, or substantially improved buildings.
2. If flood-proofing techniques were used-for buildings,
the mean sea level elevation to which the flood
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proofing was accomplished must be certified by a
structural engineer or licensed architect in the same
manner.
3. certification shall also be required, for artificial
obstructions other than buildings, that the activity
was accomplished in accordance with these regulations
and the design plans submitted with the application for
the permit activity. ,This certification may.be wai'-"ed
by the floodplain administrator if it can be clearly
ascertained by a site inspection that the activity was
accomplished in accordance with these regulations.
4. certification of flood-proofing and/or elevation shall
be provided on a standard form available from the
floodplain administrator.
section 16 Emeraencv Waiver
A. Emergency repair and replacement of severely damaged public
transportation facilities, public water and sewer
facilities, and flood control works may be authorized.
Floodplain development permit requirements may be waived if:
1. Upon notification and prior to the emergency repair
and/or replacement, the Floodplain Administrator
determines that an emergency condition exists
warranting immediate action; and
2. The Floodplain Administrator agrees upon the nature and
type of proposed emergency repair and/or replacement.
B. Authorization to undertake emergency repair and replacement
work may be given verbally if the Floodplain Administrator
feels that such a written authorization would unduly delay
the emergency works. Such verbal authorization must be
followed by a written authorization describing the emergency
condition, and the type of emergency work agreed upon, and
stating that a verbal authorization had been previously
given.
sectioD 17 Reviev-Variances-ADDea1s
A. There is hereby created a local Floodplain Management Board
of Adjustment, the membership, administration, and rules of
procedure of which are identical to a zoning board of
adjustment.
B. The Board of Adjustment may, by variance, grant a permit
that is not in compliance with the minimum standards
contained in these regulations according to the following
procedures:
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1. Variances shall not be issued for areas within a
floodway if any additional increase in flood elevations
or velocities after allowable encroachments into the
floodway fringe would result;
2. Variances shall only be issued upon:
a. a showing of good and sufficient cause;
b. a determination that refusal of a permit due to
exceptional circumstances would cause a unique or
undue hardship on the applicant or community
involved;
c. a determination that the granting of a variance
will not result in increased flood hazards,
present additional threats to public safety, be an
extraordinary public expense, create nuisances,
cause fraud, victimize the public, or conflict
with existing state and local laws;
d. a determination that the proposed use would be
adequately flood-proofed;
e. a determination that a reasonable alternate
location outside the floodplain is not available;
f. a determination that the variance requested is the
minimum necessary to afford relief, considering
the flood hazard; and
g. approval of the Montana Department of Natural
Resources and Conservation, upon request from the
Permit Issuing Authority, prior to formally
approving any permit application that is in
variance to these regulations.
3. Variances shall be issued in writing from the Permit Issuing
Authority and shall notify the applicant that:
a. a specific variance is granted, and certain conditions
may be attached;
b. the issuance of a variance to construct a building
below the lOo-year floOdplain elevation will result in
increased premium rates; and
c. such construction below the 100-year flood elevation
increases risks to life and property. The Floodplain
Administrator shall maintain records of the variance
notification and actions, including justification for
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their issuance, and forward copies of all variance
actions to the Montana Department of Natural Resources
and Conservation and the Federal Emergency Management
Agency.
C. Appeal of any decision of the Permit Issuing Authority, its
officers, or agencies may be taken by an aggrieved person or
persons, jointly or separately, to a court of record.
section 18 Pees
Fees shall be established by resolution of the City Commission
and shall be submitted with each permit application.
section 19 violation Notice
The Floodplain Administrator shall bring any violation of these
regulations to the attention of the local governing body; its
legal council; and the Montana Department of Natural Resources
and Conservation.
Section 20 ComDliance
Any use, arrangement, or construction not in compliance as
authorized by permit, shall be deemed a violation of these
regulations and punishable as provided in section 21. An
applicant is required to submit certification by a registered
professional engineer, architect, land surveyor, or other
qualified person designated by the Floodplain Administrator that
finished fill and lowest building floor elevations, flood
proofing, hydraulic design, or other flood protection measures
were accomplished in compliance with these regulations.
Section 21 Penalties
violation of the provisions of these regulations or failure to
comply with any of the requirements, including permit approval
prior to development of flood prone lands and conditions and
safeguards established shall constitute a misdemeanor. Any
person who violates these regulations or fails to comply with any
of its requirements shall, upon conviction, be fined not more
than $100 or imprisoned in jail for not more than 10 days or
both. Each day's continuance of a violation shall be deemed a
separate and distinct offense.
section 22 Bmeraencv PreDaredness Plannina
In formulating community development goals, the community shall
consider the development of a plan for evacuating residents of
all manufactured home parks or subdivisions located within flood
prone areas. This plan should be developed, filed with, and
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approved by appropriate community emergency management
authorities.
section 23 ADDlications
The minimum floodplain development standards listed in this
chapter apply to the floodway and floodway fringe portions of the
100-year floodplain as delineated on the Flood Hazard Area Maps.
section 24 Ploo4wav
A. Uses Allowed without Permits. The following open-space uses
shall be allowed without a permit within the floodway,
provided that such uses conform to the provisions of
Sections 29 and 30 of these regulations; are not prohibited
by any other ordinance, resolution, or statute; and do not
require fill, excavation, permanent storage of materials, or
equipment or structures other than portable structures:
1. Agricultural uses;
2. Accessory uses such as loading and parking areas, or
emergency landing strips associated with industrial and
commercial facilities;
3. Private and public recreational uses such as golf
courses, driving ranges, archery ranges, picnic
grounds, boat-launching ramps, parks, wildlife
management and natural areas, game farms, fish
hatcheries, shooting preserves, target ranges, trap and
skeet ranges, hunting and fishing areas, and hiking or
horseback riding trails;
4. Forestry, including processing of forest products with
portable equipment;
5. Residential uses such'as lawns, gardens, parking areas,
and play areas;
6. Irrigation and livestock supply wells, provided that
they are located at least 500 feet from domestic water
supply wells;
7. Fences, except permanent fences crossing channels; and
8. Recreational vehicles provided that they be on the site
for fewer than 180 consecutive days, or 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 with wheels intact, is attached to
the site only by quick disconnect type utilities and
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security devices, and has no permanently attached
additions.
B. Uses Reauirina Permits. The following artificial
obstructions may be permitted in the floodway subject to the
issuance of a permit by the Floodplain Administrator: (-,
1. Excavation of material from pits and pools provided
that:
a. a buffer strip of undisturbed land is left between
the edge of the channel and the edge of the
excavation. This buffer strip must be of
sufficient width to prevent flood flows from
channeling into the excavation;
b. the excavation meets all applicable laws and
regulations of other local and state agencies; and
c. excavated material is disposed of or stockpiled
outside the floodway.
2. Railroad, highway, and street stream crossings provided
the crossings are designed to offer minimal obstruction
to flood flow. stream crossings shall not increase the
elevation of the 100-year flood more than one-half foot
nor cause a significant increase in flood velocities.
3. Limited filling for highway, street, and railroad
embankments not associated with stream crossings,
provided that:
a. reasonable alternate transportation routes outside
the designated floodway are not available; and
b. such floodway encroachment is located as far from
the stream channel as possible and shall not
result in a cumulative increase in base flood
elevations, after allowable encroachments into the
floodway fringe, exceeding one-half foot.
4. Buried or suspended utility transmission lines,
provided that:
a. suspended utility transmission lines are designed
so the lowest point of the suspended line is at
least 6 feet higher than the base flood elevation;
b. towers and other appurtenant structures are
designed and placed to withstand and minimally
. obstruct flood flows; and
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c. utility transmission lines carrying toxic or
flammable materials are buried to a depth of at
least twice the calculated maximum depth of scour
for a lOO-year flood. The maximum depth of scour
shall be determined by hydraulic engineering
methods acceptable to the Floodplain
Administrator.
5. storage of materials and equipment, provided that: ,t
a. the material or equipment is not subject to major
damage by flooding and is properly anchored to
prevent floatation or downstream movement; or
b. the material or equipment is readily movable
within the limited time available after flood
warning. storage of flammable, toxic, hazardous,
or explosive materials shall not be permitted.
6. Domestic water supply wells, provided that:
a. they are driven or drilled wells located on ground
higher than the surrounding ground to assure
positive drainage from the well;
b. well casings are water tight to a distance of at
least 25 feet below the ground surface;
c. water supply and electrical lines have a
watertight seal where the lines enter the casing;
d. all pumps, electrical lines, and equipment are
either submersible or adequately flood-proofed;
and
e. check valves are installed on main water lines at
wells and at all building entry locations.
7. Buried and sealed vaults for sewage disposal in
recreational areas, provided they meet applicable laws
and standards administered by the Montana Department of
Health and Environmental Sciences.
8. Public or private campgrounds, provided that:
a. access roads require only limited fill and do not
obstruct or divert flood waters; and
b. recreational vehicles and travel trailers are
licensed and ready for highway use. They are
ready for highway use if on wheels or jacking
system with wheels intact, are attached to the
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site with only quick disconnect type utilities and
securing devices, and have no permanently attached
additions.
9. structures accessory to the uses permitted in this
section such as boat docks, marinas, sheds, picnic
shelters, tables, and toilets provided that: .,
a. the structures are not intended for human
habitation:
b. the structures will have a low flood damage
potential:
c. the structures will, insofar as possible, be
located on ground higher than the surrounding
ground and as far from the channel as possible:
d. the flood-proofing standards of Sections 29 and 30
are met: and
e. the structures will be constructed and placed so
as to offer minimal obstruction to flood flows and
are anchored to prevent floatation.
10. Replacement of manufactured homes in an existing
manufactured home park or subdivision on a developed
site with servicing utilities. The replacement home
must be elevated on a permanent foundation so the
lowest floor is two feet above the base flood elevation
or 36 inches in height above grade. The foundation
must be reinforced concrete, reinforced mortared block,
reinforced piers, or other foundation elements of at
least equivalent strength. The manufactured home
chassis must be securely anchored to the foundation
system so that it will resist floatation, collapse, and
lateral movement. Methods of anchoring may include,
but are not limited to, use of over-the-top or frame
ties to ground anchors.
11- substantial improvements to any structure provided that
the provisions of section 25 (B)3, 25 (B)4, or 25(B)5
of these regulations are met. In the floodway the
structure must be floodproofed or elevated on a
permanent foundation rather than on fill.
12. All other artificial obstructions, substantial
improvements, or non-conforming uses not specifically
listed or prohibited by these regulations.
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C. Permits for Flood Control Works. Flood control works shall
be allowed within floodways subject to the issuance of a
permit by the Floodplain Administrator with the following
conditions:
1. Levees and floodwalls are permitted if:
a. the proposed levee or floodwall is designed and
constructed to safely convey a laO-year flood: and
b. the cumulative effect of the levee or floodwall
combined with allowable floodway fringe
encroachments does not increase the unobstructed
base flood elevation more than 0.5 foot. The
Floodplain Administrator may establish either a
lower or higher permissible increase in the base
flood elevation for individual levee projects only
with concurrence from the Montana Department of
Natural Resources and Conservation and the Federal
Emergency Management Agency based upon
consideration of the following criteria:
1) the estimated cumulative effect of any
anticipated future permissible uses: and
2) the type and amount of existing flood-prone
development in the affected area.
c. the proposed levee or floodwall, except those to
protect agricultural land, are constructed at
least 3 feet higher than the base flood elevation.
2. Riprap, except that which is hand-placed, if:
a. the riprap is designed to withstand a 100-year
flood:
b. the riprap does not increase the base flood
elevation; and
c. the riprap will not increase erosion upstream,
downstream, or adjacent to the riprap site.
3. Channelization projects if they do not significantly
increase the magnitude, velocity, or base flood
. elevation in the proximity of the project.
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4. Dams, provided that:
a. they are designed and constructed in accordance
with the Montana Dam Safety Act and applicable
safety standards: and ,-.
b. they will not increase flood hazards downstream,
either through operational procedures or improper
hydrologic/hydraulic design. ..'
D. Permits for Water Diversions. Permits for the establishment
of a water diversion or change in place of diversion shall
not be issued if, in the judgment of the Floodplain
Administrator:
1. the proposed diversion will significantly increase the
upstream base flood elevation to the detriment of
neighboring property:
2. the proposed diversion is not designed and constructed
to minimize potential erosion from a 100~year flood:
and
3. any permanent diversion structure crossing the full
width of the stream channel is not designed and
constructed to safely withstand a 100-year flood.
E. prohibited Uses. The following artificial obstructions and
non-conforming uses are prohibited within the floodway:
1. New construction of any residential, commercial, or
industrial structure including manufactured homes:
2. Encroachments including fill, new construction,
alterations, substantial improvements, and other
development within the adopted regulatory floodway that
would result in erosion of the embankment, obstruction
of the natural flow of waters, or increase in flood
levels within the community during the occurrence of
the 100-year flood:
3. The construction or permanent storage of an object
Subject to floatation or movement during flooding:
4. Solid and hazardous waste disposal, sewage treatment,
and sewage disposal systems:
5. Storage of toxic, flammable, hazardous, or explosive
materials: and
6. Alterations of structures unless it can be shown the
alteration won't raise flood heights.
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Section 25 F100dwav prinae
A. Uses Allowed Without Permits. All uses allowed in the
floodway, according to the provisions of section 24(A) of
these regulations, shall also be allowed without a permit in
the floodway fringe.' In addition, individual or multiple
family subsurface sewage disposal systems are allowed only
when they are reviewed and approved under laws and
regulations administered by the Department of Health and
Environmental Sciences.or the local health board.
B. Uses Reauirina Permits. All uses allowed in the floodway
subject to the issuance of a permit, according to the
provisions of Section 24(B), 24(C), and 24(D) of these
regulations, shall also be allowed by permit within the
floodway fringe. In addition, new construction, substantial
improvements, and alterations to structures are allowed by
permit. This includes but is not limited to residential,
commercial, and industrial construction and suitable fill to
be allowed by permit from the Floodplain Administrator,
SUbject to the following conditions:
1. Such structures or fill must not be prohibited by any
other statute, regulation, ordinance, or resolution;
2. Such structures or fill must be compatible with local
comprehensive plans;
3. The new construction, alterations, and substantial
improvements of residential structures including
manufactured homes must be constructed on suitable fill
such that the lowest floor elevation (including
basement) is two feet or more above the base flood
elevation. The suitable fill shall be at an elevation
no lower than the base flood elevation and shall extend
for at least fifteen feet, at that elevation, beyond
the structure(s) in all directions:
4. The new construction, alteration, and substantial
improvement of commercial and industrial structures can
be constructed on suitable fill as specified in Section
25(B)3 of these regulations. If not constructed on
fill, commercial and industrial structures must be
adequately flood-proofed to an elevation no lower than
two feet above the base flood elevation.
Flood-proofing must be certified by a registered
professional engineer or architect that the
flood-proofing methods are adequate to withstand the
flood depths, hydrodynamic and hydrostatic pressures,
velocities, impact, buoyancy, and uplift forces
associated with the lOO-year flood.
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a. If the structure is designed to allow internal
flooding of areas below the lowest floor, use of
this space shall be limited to parking, loading
areas, building access, and storage of equipment
or materials not appreciably affected by flood
waters. The floors and walls shall be designed
and constructed of materials resistant to flooding
to an elevation no lower than two feet above the
base flood elevation. Walls shall be designed to
automatically equalize hydrostatic forces by
allowing for entry and exit of floodwaters.
Openings may be equipped with screens, louvres,
valves, other coverings, or devices which permit
the automatic entry and exit of floodwaters.
b. structures whose lowest floors are used for a
purpose other than parking, loading, or storage of
materials resistant to flooding shall be flood-
proofed to an elevation no lower than two feet
above the base flood elevation. Flood-proofing
shall include impermeable membranes or materials
for floors and walls and watertight enclosures for
all windows, doors, and other openings. These
structures shall also be designed to withstand the
hydrostatic, hydrodynamic, and buoyancy effects of
a 100-year flood.
c. Flood-proofing of electrical, heating, and
plumbing systems shall be accomplished in
accordance with Sections 29 and 30 of these
regulations.
5. All manufactured homes placed in the floodway fringe
must have the chassis securely anchored to a foundation
system that will resist floatation, collapse, or
lateral movement. Methods of anchoring may include,
but are not limited to, over-the-top or frame ties to
ground anchors. The following conditions also apply:
a. When a manufactured home is 1) altered, 2)
replaced because of substantial damage as a result
of a flood, or 3) replaced on an individual site,
the lowest floor must be elevated two feet above
the base flood elevation. The home can be
elevated on fill or raised on a permanent
foundation of reinforced concrete, reinforced
mortared block, reinforced piers, or other
foundation elements of at least equivalent
strength.
.
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b. Replacement or substantial improvement of
manufactured homes in an existing manufactured
home park or subdivision must be raised on a
permanent foundation. The lowest floor must be at
least 36 inches above the ground or raised two
feet above the base flood elevation, whichever is
less. The foundation must consist of reinforced
concrete, reinforced mortared block, reinforced
piers, or other foundation elements of at least
equivalent strength.
c. Manufactured homes proposed for use as commercial
or industrial structures must be elevated and
anchored, rather than flood-proofed:
6. Fill material placed in the floodway fringe must be
stable, compacted, well graded, pervious, generally
unaffected by water and frost, devoid of trash or
similar foreign matter, devoid of tree stumps or other
organic material, and appropriate for the purpose of
supporting the intended use and/or permanent structure.
7. Roads, streets, highways, and rail lines shall be
designed to minimize increase in flood heights. Where
failure or interruption of transportation facilities
would result in danger to the pUblic health or safety,
the facility shall be located two feet above the base
flood elevation:
8. Agricultural structures that have a low damage
potential, such as sheds, barns, shelters, and hay or
grain storage structures must be adequately anchored to
prevent floatation or collapse and all electrical
facilities shall be placed above the base flood
elevation: and
9. Recreational vehicles, if they are on the site for more
than 180 consecutive days or are not ready for highway
use, must meet the elevating requirements of Section
25(B)3.
c. Prohibited Uses. The following artificial obstructions and
non-conforming uses are prohibited within the floodway
fringe:
1. Solid and hazardous waste disposal: and
2. Storage of highly toxic, flammable, hazardous, or
explosive materials. storage of petroleum products may
be allowed by permit if stored on compacted fill at
least two feet above the base "flood elevation and
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anchored to a permanent foundation to prevent
downstream movement.
s.c~ion 26 PloodD1ain Areas with P100d Blevations and No
Delineated Ploodwav
A. A development proposed for a 100-year floodplain, where
water surface elevations are available but no floodway is
delineated, may not significantly increase flood velocities
or depths or generally alter patterns of flood flow. The
provisions of Section 25 Floodway Fringe, shall apply to
these areas. The Floodplain Administrator may require a
permit applicant to furnish additional hydraulic data before
acting on a permit application for such a floodplain. The
data may include, but are not limited to, any of the
following:
1- a hydraulic study documenting probable effect on
upstream, downstream, or adjacent property owners
caused by the proposed development: or
2. the calculated increase in the 100-year flood water
surface profile caused by the proposed development.
B. Permits for such proposed development may be modified or
denied if the additional information shows that the proposed
use would cause an additional flood hazard to adjacent
property or significantly increase flood heights. A
significant increase in flood heights is one-half foot
unless existing or anticipated development in the area
dictates a lesser amount of allowable increase.
section 27 Shallow Ploodina fAO Zones)
A. Shallow flooding areas are delineated as AO Zone floodplains
on the Flood Insurance Rate Maps. The provisions of Section
25 Floodway Fringe, of these regulations shall apply to any
AO Zone floodplains. The depth of the 100 year flood is
indicated as the depth number on the Flood Insurance Rate
Maps. The lOa-year flood depth shall be referenced to the
highest adjacent grade or stream flow line in determining
which fill or flood-proofing heights to use in applying the
provisions of Section 25(B)3 and Section 25(B)4 of these
regulations. In the absence of depth or elevation
information, a minimum 2 foot flood depth shall be used.
B. Floodplain Boundarv Interoretation. The Floodplain
Administrator shall make interpretations where needed as to
the exact location of an AO Zone floodplain boundary when
there is a conflict between a mapped boundary and actual
field conditions.
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section 28 ADDlications
The minimum floodplain development standards listed in this
section apply to the lOO-year floodplains delineated by
approximate methods and identified as unnumbered A Zones on
the Flood Insurance Rate Maps.
A. Uses Allowed Without Permits. All uses allowed in ,_a
floodway, according to the provisions of section 24(A) of
these regulations, shall also be allowed without,a permit in
unnumbered A-Zone floodplains.
B. Uses Reauirinq Permits. All uses allowed in the floodway
and floodway fringe subject to the issuance of a permit,
according to the provisions of Section 25(8), shall require
permits from the Floodplain Administrator for unnumbered A-
Zone floodplains. Also, the provisions of Section 25(8)
apply to the A-Zone floodplains with no floodway delineated
or water surface profile computed. Since there are no
100-year flood water surface profiles computed for A-Zone
floodplains, the following conditions also apply:
1- Elevation data on the 100-year flood shall be provided
for subdivision proposals according to the definitions
and rules of the Montana Sanitation in Subdivisions
Act, MeA 76-4 Part 1 and the rules adopted by DHES
under this Act. These data shall be used in applying
Sections 25(B)3, 25(B)4, and 25(8)5 of these
regulations. Subdivision proposals shall also provide
for adequate drainage to minimize potential flood
hazards.
2. The Floodplain Administrator may obtain, review, and
reasonably use any base flood elevation and floodway
data available from federal, state, or other sources,
until such data have been provided by FEMA, to enforce
Section 25(B)3 and 25(B)4 of these regulations: and
3. The Floodplain Administrator may use historical flood
elevations to determine suitable fill or flood-proofing
elevations as required by Sections 25(B)3 and 25(B)4 of
these regulations:
4. If historical flood evidence is not available, then the
Floodplain Administrator shall determine, from a field
review at the proposed development site, an appropriate
fill or flood-proofing elevation to use in applying
Sections 25(B)3 and 25(8)4 of these regulations. In
the absence of depth or elevation information, a
minimum two-foot flood depth shall be used: and
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5. Proposed structures must be anchored to prevent
floatation or collapse and must be located as far from
stream channels as practicable.
c. Prohibited Uses. Those uses prohibited in the floodway
fringe, in accordance with Section 25(C) of these
regulations, shall also be prohibited within the A-Zone
floodplain boundaries.
D. FloodDlain Boundarv Interoretation. The Floodplain
. Administrator shall make interpretations where needed as to
the exact location of the unnumbered A-Zone floodplain
boundary when there is a conflict between a mapped boundary
and actual field conditions.
section 29 Certification
If the following flood-proofing requirements are to be
applied to a proposed structure, as stipulated by the
Floodplain Administrator in accordance with these
regulations, the methods used must be certified as adequate
by a registered professional engineer or architect.
Section 30 Conformance
Permitted flood-proof systems shall conform to the
conditions listed below--and the floOd-proofing standards
listed in Section 25(B)4 of these regulations for commercial
and industrial structures.
A. Electrical Systems
1- All incoming power service equipment, including all
metering equipment, control centers, transformers,
distribution and lighting panels, and all other
stationary equipment must be located at least two feet
above the base flood elevation:
2. Portable or movable electrical equipment may be placed
below the base flood elevation, if the equipment can be
disconnected by a single submersible plug-and-socket
assembly:
3. The main power service line shall have automatic or
manually operated electrical disconnect equipment
located at an accessible location outside the lOa-year
floodplain and above the base flood elevation: and
4. All electrical wiring systems installed at or below the
elevation of the lOa-year flood shall be suitable for
continuous submergence and may not contain fibrous
components.
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B. Heatina Systems
1. Float operated automatic control valves must be
installed in gas furnace supply lines so that the fuel
supply is automatically shut off when flood waters
reach the floor level where the furnace is located:
2. Manually operated gate valves must be installed in gas
supply lines. The gate valves must be operable from a
location above the elevation of the 100-year flood.
3. Electric heating systems must be installed in
accordance with the provisions of Section 30(A).
c. Plumbina sVstems
1- Sewer lines, except those to be buried and sealed in
vaults, must have check valves installed to prevent
sewage backup into permitted structures: and
2. All toilet stools, sinks, urinals, and drains must be
located so the lowest point of possible water entry is
at least two feet above the elevation of the 100-year
flood.
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