HomeMy WebLinkAboutOrdinance 82- 1097 Amends prior code Ch. 18.66, flood hazard district
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ORDINANCE NO. 1097
AN ORDINANCE OF THE CITY COMMISSION OF THE
CITY OF BOZEMAN, MONT ANA, AMENDING CHAPTER
18.66 OF THE BOZEMAN MUNICIPAL CODE PROVIDING
FOR A FLOOD HAZARD DISTRICT IN THE CITY OF
I BOZEMAN, MONT ANA.
BE IT ORDAINED BY THE CITY COMMISSION OF THE CITY OF BOZEMAN:
SECTION 1
That Chapter 18.66 of the Bozeman Municipal Code be, and the same is hereby
amended to read as follows:
SECTION 2
18.66.010 Intent
This Chapter shall be known and ci ted as the Bozeman Area Flood Hazard District. Its
provisions are in accordance with exercising the authority of the laws of the State of Montana.
The purpose of this Chapter is 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
flood plain. The provisions of this Chapter have been established with the folhwing purposes
intended:
l. To guide development of the 100-year flood plain areas within Bozeman's Jurisdictional
Zoning Area and make it consistent with the enumerated findings by:
a. Recognizing the right and need of water courses to periodically carry more than
the normal flow of water;
I b. Participating in coordinating efforts of federal, state, and local management
activities for 100-year flood plains;
c. Insuring the regulations and minimum standards adopted, insofar as possible,
balance the greatest public good with the least private injury.
2. Specifically it is the purpose of this Chapter to:
a. Restrict or prohibit uses which are dangerous to health, safety of property in
times of flood, or cause increased of flood heights or velocities;
b. Require that uses vulnerable to floods, including public facilities which serve
such uses, be provided with flood protection at the time of initial construction;
c. Utilize information which identifies lands which are unsuited for certain develop-
ment purposes because flood hazards;
d. Minimize the need for rescue and relief efforts associated with flooding and
generally undertaken at the expense of the general public;
e. Ensure that potential buyers are notified that property is within a 100-year
flood plain and subject to the provisions of this Chapter; and
f. Ensure that those who occupy 100-year flood plains assume responsibility for
their actions.
18.66.020 SPECIAL DEFINITIONS
Unless specifically defined below, words or phrases used in this Chapter shall be governed
by Chapter 18.06.
I l. Alteration
Any change or addition to a structure that increases its external dimensions.
2. A ppeal
A request for a review of the interpretation by the Flood Plain Administrator of any
provision of this Chapter or a request for a variance.
3. Area of Specific Flood Hazard
The land in the flood plain within the community subject to inundation by a one
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percent (1%) or greater chance of flood in any given year; i.e., the 100-year flood
plain.
4. Artificial Obstruction--Development
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 I
other analogous structure or matter in. along. across or projecting into any 100-year
flood plain. 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. that is placed
where the natural flow of water would carry the same downstream to the damage or
detriment of either life of property.
5. Base Flood
A flood having a one percent (1%) change of being equalled or exceeded in any given
year.
6. Channelization Project
The excavation and/or construction of an artificial channel for the purpose of diverting
the entire flow of a stream from its established course.
7. Establish
To construct. place, insert, or excavate.
8. Flood or Flooding
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
to surface waters from any source.
9. Flood Plain
The areas adjoining a stream which would be covered by floodwater.
10. Floodway I
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.
II. Floodway Fringe
That portion of the flood plain outside the limits of the flood way .
12. Flood Insurance Rate Map
The map on which the Federal Insurance Administration has delineated both the
100-year flood plains and the risk premium zones.
13. Flood Insurance Study
The report in which the Federal Insurance Administration has provided flood profiles.
as well as the Flood Boundary and Floodway Map and the Water Surface Profiles.
14. Lowest Floor Elevation
Any fbor usable. or which could be converted to a use for living purposes. storage.
or recreation.
15. New Construction
Structures for which the start of construction, substantial improvement or alteration
commences on or after the effective date of this Chapter.
16. Official Flood Plain Maps
The Flood Insurance Rate Maps and Flood Boundary--Floodway Maps provided by the I
Federal Insurance Administration for Bozeman. Montana. dated March 15. 1982.
17. Riprap
Stone. rocks, concrete blocks, or analogous material that is placed along the banks
or bed of a stream for the purpose of alleviating erosion.
18. Start of Construction
The first placement of permanent construction of a structure (other than a mobile
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home) on a site, such as pouring of slabs or footings or any work beyond the state
of excavation. 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 the excavation for a basement, footings, piers or
foundation or the erection of a temporary form; nor does it include the installation
on the property of accessory buildings, such as garages or sheds not occupied as
dwelling units or not as part of the main structure. For a structure (other than
a mobile home) without a basement or poured footings, the start of construction
I includes the first permanent framing or assembly of the structure or any part thereof
on its piling or foundation. For mobile homes not within a mobile home park or mobile
home subdivisions, start of construction is the date on which the construction of
facilities for servicing the site on which the mobile home is to be affixed to (including,
at a minimum, the construction of streets, either final site grading or the pouring of
concrete pads, and the installation of utilities) is completed.
19. Substantial Improvement
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:
a. before the improvement or repair is started; or
b. 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. A substantial improvement differs from the alteration of a
structure in that it is not defined to include increasing or affecting the external
dimensions of the structure. The term also does not include either:
(1) 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
(2) Any alteration of a structure listed on the National Register of Historic Places
or State Inventory of Historic Places.
I 20. Suitable Fill
Fill material which is stable, compacted, well graded, pervious, generally unaffected
by water and frost, devoid of trash or similar foreign matter, and tree stumps or
other organic material; and is fitted for the purpose of supporting the intended use
and/or permanent structure.
18.66.030 DISTRICT BOUNDARIES AND DELINEATION
The provisions of this Chapter shall apply to all lands within the Zoning Jurisdiction of the
City of Bozeman, State of Montana, shown on the Official Flood Plain Maps as being heated
within a 100-year flood plain district.
18.66.031 FLOOD PLAIN DISTRICT ESTABLISHMENT
The flood plain districts established are defined by the 100-year flood plains as delineated
in the Bozeman Area 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 September 15, 1981, with accompanying Flood Insurance Rate
Maps and Flood Boundary and Floodway Maps. The Official Flood Plain Maps, together with
the Flood Insurance Report, are on file in the Office of the Bozeman Flood Plain Admini-
strator.
18.66.032 CITY OF BOZEMAN FLOOD PLAIN ADMINISTRATOR
The Flood Plain Administrator for the City of Bozeman and its jurisdictional area has been
I designated to be the City Engineer. The responsibilities of this position are outlined in
Section 18.66.040 of this Chapter.
18.66.033 RULES FOR INTERPRETATION OF FLOOD PLAIN
DISTRICT BOUNDARIES
The boundaries of the 100-year flood plain and flood way shall be determined by scaling
distances on the Official Flood Plan Maps. Where there appears to be a conflict between
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a mapped flood plain boundary and the actual field conditions, the Bozeman Flood Plain
Administrator may determine that the area is not to be included within the lOO-year flood
plain. The property owner or developer would then not have to satisfy the provisions of
the Chapter.
18.66.034 COMPLIANCE
No structure or land use shall be located, extended, converted or structurally altered I
without full compliance with the provisions of this Chapter and other applicable regulations.
The divisions established within this Chapter meet the minimum flood plain development
requirements as set forth by the Montana Board of Natural Resources and Conservation
and in the National Flood Insurance Program Regulations.
18.66.035 ABROGATION AND GREATER RESPPONSIBILITY
It is not intended by the provisions of this Chapter to repeal, abrogate or impair any
existing easements, covenants, deed restrictions, or underlying zoning. However, where
this Chapter imposes greater restrictions, the provisions of this Chapter shall prevail.
18.66.036 REGULATION INTERPRETATION
In their interpretation and application, the provisions of this Chapter shall be held to be
minimum requirements and shall be liberally construed in favor of the governing body and
shall not be deemed a limitation or repeal of any other powers granted by State Statute.
18.66.037 WARNING AND DISCLAIMER OF LIABILITY
The provisions of this Chapter does not imply that areas outside the delineated flood plains
boundaries or permitted land uses within such areas will always be totally free from
flooding or flood damages. These provisions shall not create a liability on the part of, or
cause of action against the City of Bozeman or any officer or employee thereof for any
flood damages that may result from reliance upon the provisions of this Chapter or
Regulations.
18.66.038 DISCLOSURE PROVISION I
All owners of property in an identified 100-year flood plan as indicated on the Official
Flood Plain Maps must notify potential buyers or their agents that such property is subject
to the provisions of this Chapter. Upon resale of property, the lending institution must
notify potential buyers ten (10) days prior to closing that the property is located within
a special flood hazard area. The lender must also notify potential buyers whether, in the
event of a flood disaster, federal disaster relief would be available to the property.
18.66.040 ADMINISTRATION
As provided in Section 18.66.032 of this Chapter, the Bozeman Flood Plain Administrator
has been designated by the City Commission and has the responsibility of such position as
outlined in this Chapter.
The Flood Plain Administrator is hereby appointed with the authority to review flood plain
development permit applications and proposed uses or construction to determine compliance
with the provisions of this Chapter and 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 D.S.C. 1334.
1. Addi tional Factors
Flood Plain Development Permits shall be granted or denied by the Flood Plain
Administrator on the basis of whether the proposed establishment, alteration, or
substantial improvement of an artificial obstruction or nonconforming use meets the
requirements of this Chapter. 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 I
water velocities or alterations in the pattern of flood flow caused by encroach-
ments;
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 ahility of these systeT"'s
to prevent disease, contamination and unsanitary conditions;
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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 water front location;
g. The availability of alternative locations not subject to flooding for the proposed
I use;
h. The compatability 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 flood plain
management for the area;
j . The safety of access to property in times of fhoding for ordinary and emergency
services; and,
k. Such other factors as are in harmony with the intent of this Chapter, the Montana
Flood Plain and Floodway Management Act and the National Flood Insurance
Program.
A flood plain development permit application is considered to have been automatically
granted sixty (60) days after the date of receipt of the application by the Flood Plain
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.
The Flood Plain Administrator shall adopt such administrative procedures as may be necessary
to efficiently administer the provisions of this Chapter.
The Flood Plain Administrator shall maintain such files and records as may be necessary to
document nonconforming uses, flood elevations, fee receipts, the issuance of permits, agendas,
minutes, records of public meetings, and any other matters related to flood plain management
in the Bozeman Jurisdictional Zoning Area. Such files and records shall be open for public
inspection. In matters of litigation, the Bozeman City Attorney may restrict access to
specific records.
I Copies of all permits granted must be sent to the Department of Natural Resources and
Conservation in Helena, Montana.
In riverine situations, notification by the Flood Plain Administrator must be made to adjacent
communities, the Flood Plain Management Section (DNRC) and the Federal Insurance
Administration, 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.
18.66.050 PERMIT APPLICATIONS
l. Activities or uses which 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 Flood Plain Administrator.
2. Permit applicants may be required to furnish any of the following information as is
deemed necessary by the Flood Plain Administrator for determining the suitability of
the particular site for the proposed use:
a. Plans in duplicate drawn to scale with dimensions shown, showing the nature,
location and elevation of the lot, existing and proposed structure locations, fill,
storage or materials site, flood proofing measures, first floor of proposed
structures in mean sea leavel elevation and location of the channel; and
b. A plan view of the proposed development indicating external dimensions of
structures, street or road finished grade elevations, well location, individual
sewage treatment and disposal site, excavation and/or fill quantity estimates, site
plan and/or construction plans.
c. Specifications for fhod proofing, filling, excavating, grading, riprapping, storage
of materials and utilities location.
I 3. Applicants who have received permits are required to furnish the folhwing, at the
time of an on-site conformance inspection, for determining that the permit specifications
and conditions have been complied with:
a. Certification by a registered professional engineer or licensed land surveyor the
actual mean sea leavel elevation of the lowest floor (including basement) of all
new, altered or substantially im!'lroven structures. If flood proofing techniques
were utilized for the above described structures, then the mean sea level elevation
to which the fhod proofing was accomplished must be similarly certified.
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18.66.060 EMERGENCY WAIVER
Emergency repair to and/or replacement of severely damaged public transportation facilities,
public water and sewer facilities and flood control works may be authorized and flood plain
development permit requirements waived if:
l. Upon notification and prior to the emergency repair and/or replacement, the Flood
Plain Administrator determines that an emergency condition warranting immediate action I
exists; and
2. The Flood Plain Administrator agrees upon the nature and type of proposed emergency
repair and/or replacement. Authorization to undertake emergency repair and/or
replacement work may be given verbally if the Flood Plain Administrator feels that
such a written authorization would unduly delay the emergency works. Such verbal
authorization must be followed by a written authorization stating the emergency condition,
the type of emergency work agreed upon, and a notation that a verbal authorization
had been previously given.
18.66.070 REVIEW-- V ARIANCES--APPEALS
Appeals and variances may be granted by the Board of Adjustment in accordance with the
provisions of Chapter 18.93 of this Zoning Code, but only according to the following
procedures:
l. Variances shall not be issued for areas wi thin a flood way if any increase in flood
elevations or velocities 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 would, because of exceptional
circumstances, 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
heights, additional threats to public safety, extraordinary public expense, create I
nuisances, cause fraud on or victimization of the public, or conflict with existing
state or local laws;
d. A determination that a proposed use would be adequately flood proofed;
e. A determination that a reasonable alternative location outside the flood plain is
not available;
f- A determination that the variance requested is the minimum necessary, considering
the flood hazard, to afford relief; and
g. An approval of the Montana Department of Natural Resources and Conservation is
obtained upon request from the Board of Adjustment prior to formally approving
any permit application which is in variation to this Chapter.
3. Variances shall be issued in writing from the Board of Adjustment and shall notify
the applicant that:
a. The specific variance that is granted, along with any conditions attached thereon;
b. The issuance of a variance to construct a structure below the 100-year flood
plain elevation will result in increased premium rates for flood insurance up to
amounts as high as twenty-five dollars ($25) for one hundred dollars ($100)
of insurance coverage; and
c. Such construction below the 100-year flood elevation increases risks to life and
property. The Flood Plain Administrator shall maintain the records of variance
notification, variance actions, including justification for their issuance and forward
copies of all variance actions to the Montana Department of Natural Resources
and Conservation.
4. Appeals from any decision of the Board of Adjustment or its officers or agencies may I
be taken by an aggrieved person or persons, jointly or separately aggrieved, to a
court of record.
18.66.080 FEES
A processing fee of twenty-five dollars ($25) shall be submitted with each permit application.
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18.66.090 VIOLATION NOTICE
The Flood Plain Administrator shall be responsible for citing for any violation of this
Chapter and shall notify the Bozeman City Attorney and the Montana Department of Natural
Resources and Conservation of any violations.
I 18.66.100 COMPLIANCE
Any use. arrangement or construction not in compliance with that authorized shall be deemed
a violation of these Regulations, and punishable as provided in Section 18.99.020. An
applicant may be required to submit certification by a registered professional engineer,
architect or other qualified person designated by the Flood Plain Administrator that finished
fill and building floor elevations, flood proofing or other flood protection measures were
accomplished in compliance with the provisions of this Chapter.
18.66.110 SPECIFIC STANDARDS
The minimum flood plain development standards listed in this Chapter apply to the
floodway Ifloodway fringe portions of the 100-year flood plain as delineated on the Bozeman
Area Floodway and Flood Boundary Maps, and also correspond to the numbered A Zones
depicted on the Bozeman Flood Insurance Rate Maps.
18.66.111 FLOODWA Y
1. Uses Allowed Without Permits
The following open space use shall be allowed without a permit anywhere within the
floodway. provided that such uses conform to the provisions of Section 18.66.120 of
this Chapter, 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:
a. Agricultural uses;
I b. Accessory uses such as loading or parking areas. or emergency landing strips
associated with industrial commercial facilities;
c. Private and public recreational uses such as golf courses, driving ranges, archery
ranges, picnic grounds, boat launching ramps, parks. wildlife management and
na tural areas, game farms. fish hatcheries, shooting preserves, target ranges,
trap and skeet ranges, hunting and fishing areas, and hiking or horseback riding
trails;
d. Forestry, including processing of forest products with portable equipment;
e. Residential uses such as lawns. gardens, parking areas and play areas;
f. Irrigation and livestock supply wells. provided that they are located at least
five hundred (500) feet from domestic water supply wells; and
g. Fences, except permanent fences crossing channels.
2. Uses Requiring Permits
The following artificial obstructions and nonconforming uses may be permitted in the
floodway subject to the issuance of a permit by the Flood Plain Administrator.
a. Excavation of material from the pits and pools provided that:
(1) A buffer strip of undisturbed land of sufficient width to prevent flood
flows from channeling into the excavation is left between the edge of the
channel and the edge of the excavation;
(2) The excavation meets all applicable laws and regulations of other local and
state agencies; and.
I (3) Excavated material is stockpiled outside the flood way .
b. Railroad, highway and street stream crossings provided the crossings are designed
to offer minimal obstruction to flood flow.
c. Limited filling for highway. street and railroad embankments not associated with
stream crossings provided that:
(1) Reasonable alternative transportation routes outside the designated flood way
are not available; and
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(2) Such flood way encroachment is located as far from the stream channel as
possible.
d. Buried or suspended utility transmission lines, provided that:
(1) Suspended utility transmission lines are designed such that the lowest point
of the suspended line is at least six (6) feet higher than the elevation of the
flood of 100-year frequency; I
(2) Towers and other appurtenant structures are designed and placed to
withstand and offer minimal obstruction to flood flows; and.
(3) 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
flood of 100-year frequency. The maximum depth of scour may be determined
from any of the accepted hydraulic engineering methods, but the final
calculated figure shall be subject to approval by the Flood Plain Administrator.
e. Storage of materials and equipment provided that:
(1) The material or equipment is not subject to major damage by flooding and
is properly anchored to prevent flotation or downstream movement; or
(2) The material or equipment is readily removable within the limited time
available after flood warning. Storage of flammable. toxic or explosive
ma terials shall not be permi tted.
f. Domestic water supply wells provided that:
(1) They are driven or drilled wells located on ground higher than the
surrounding ground to assure positive drainage from the well;
(2) Well casings are water tight to a distance of at least twenty-five (25) feet
below the ground surface;
(3) Water supply and electrical lines have a watertight seal where the lines
enter the casing;
(4) All pumps. electrical lines and equipment are either of the submersible or I
are adequately flood proofed; and.
(5) Check valves are installed on main water lines at wells and all building entry
loca tions.
g. Buried and sealed vaults for sewage disposal in recreational areas provided that
they meet applicable laws and standards administered by the Montana Department
of Health and Environmental Sciences.
h. Public or private campgrouds provided that:
(1) Access roads require only limited fill and do not obstruct or divert flood
waters; and
(2) No dwellings or permanent mobile homes are allowed.
i. Structures accessory to the uses permitted in this Section such as boat docks.
marinas. sheds, picnic shelters. tables and toilets provided that:
(1) The structures are not intended for human habitation;
(2) The structures will have a low flood damage potential;
(3) The structures will. insofar as pOSSible, be located on ground higher than
the surrounding ground and as far from the channel as possible;
(4) The flood proofing standards of Section 18.66.130 are met; and,
(5) The structures will be constructed and placed so as to offer a minimal
obstruction to flood flows and also are anchored to prevent flotation.
j. Replacement of mobile homes within an existing mobile home park or mobile home I
subdivision provided that the mobile homes are anchored to resist flotation,
collapse or lateral movement by providing over-the-top frame ties. Special
requirements shall be that:
(1) Over-the-top ties be provided at each of the four (4) corners of the mobile home,
with two (2) additional ties per side at intermediate locations. with mobile homes
less than fifty (50) feet long requiring one (1) addi tional tie per side;
(2) Frame ties to be provided at each corner of the home with five (5) additional
ties per side at intermediate point, with mobile homes less than fifty (50) feet
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long requiring four (4) additional ties per side;
(3) All components of the anchoring system be capable of carrying a force of 4.800
pounds;
(4) Any additions to the mobile home must be similarly anchored; and,
I (5) Adequate surface drainage and access for a hauler are provided.
k. Substantial improvements to any structure provided that the provision of Section
18.66.112, Items 2c and 2d of this Chapter are met.
1. All other artificial obstructions. substantial improvements or nonconforming uses
not specifically listed in or prohibited by this Chapter.
3. Permits for Flood Control Works
Flood control works shall be allowed within floodways subject to the issuance of a
permit by the Flood Plain Administrator and to the following conditions:
a. Levees and flood walls are permitted if:
(1) The proposed levee or flood wall is designed and constructed to safely convey
a flood of 100-year frequency; and
(2) The cumulative effect of the levee or fhodwall combined with allowable flood way
fringe encroachments does not increase the unobstructed elevation of the flood
of 100-year frequency. The Flood Plain Administrator may establish either a
lower or higher permissible increase in the elevation of the flood of 100-year
frequency for individual levee projects. with concurrence of the Montana
Department of Natural Resources and Conservation and the Federal Insurance
Administration based upon the following criteria:
(a) The estimated cumulative effect of other reasonable anticipated future
permissible uses; and
(b) The type and amount of existing flood-prone development in the affected
area.
I (3) The proposed levee or floodwall. except those to protect agricultural land only.
are constructed at least three (3) feet higher than the elevation of a flood of
100-year frequency.
b. Riprap. except that which is hand-placed. if:
(1) The riprap is designed to withstand a flood of IOO-year frequency;
(2) The riprap does not increase the elevation of flood of 100-year frequency; and
(3) The riprap will not increase erosion upstream. downstream, or adjacent to the
riprap site.
c. Channelization projects if they do not significantly increase the magnitude. velocity or
elevation of the flood of IOO-year frequency in the proximity of the project.
d. Dams provided that:
(1) They are designed and constructed in accordance with approved safety standards;
and.
(2) They will not increase flood hazards downstream. either through operational
procedures or improper hydrologic design.
4. 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 Flood Plain Administrator:
I a. The proposed diversion will increase the upstream elevation of the f.lood of
100-year frequency;
b. The proposed diversion is not designed and constructed to minimize potential erosion
from a flood of 100-year frequency; and.
c. Any permanent diversion structure crossing the full width of the stream channel
is not designed and constructea to safely withstand ll~ to a flood of 100-year
frequency.
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5. Prohibi ted Uses
The following artificial obstructions and nonconforming uses are prohibited within the
floodway:
a. New construction and alterations of any structure;
b. Encroachments, including fill, new construction, substantial improvements, and
other development within the adopted regulatory flood way that would result in I
erosion of embankment, obstruction of the natural flow of waters, or increase in
flood levels within the community during the occurrence of the flood of 100-year
frequency.
c. The construction of permanent storage of an object subject to flotation or movement
during the flood level periods;
d. Mobile homes, except in an existing mobile home park or mobile home subdivision;
e. Solid waste disposal, water distribution systems, and sewage treatment and/or
disposal systems except as allowed or approved under the laws and standards
administered by the Montana Department of Health and Environmental Sciences;
and,
f. Storage of highly toxic, flammable or explosive materials.
18.66.112 FLOODW A Y FRINGE
1. Uses Allowed Without Permits
All uses allowed in the fbodway, according to the provisions of Section 18.66.111.1 of
this Chapter shall also be allowed without a permit in the flood way fringe.
2. Uses Requiring Permits
All uses allowed in the fJoodway subject to the issuance of a permit, according to the
provisions of Section 18.66.111, Items 2, 3, and 4, of this Chapter, shall also be
allowed by permit within the flood way fringe. In addition, new construction,
substantial improvements and alterations to structures including, but not limited to I
residential, commercial and industrial, and suitable fill shall be allowed by permit
from the Flood Plain Administrator subject to the following conditions:
a. Such structures of fill must not be prohibited by a statute, regulation, ordinance
or resolution;
b. Such structures or fill must be compatible with local comprehensive plans;
c. The new construction, alterations and substantial improvements of
residential structures must be constructed on suitable fill such that the lowest
floor elevations. (including basement) are two (2) feet or more above the elevation
of the flood of 100-year frequency and shall extend for at least fifteen (15) feet
at that elevation beyond the structures in all directions;
d. The new construction, alteration and substantial improvement of commercial and
industrial structures must be either constructed on suitable fill as specified in
paragraph 2c of this Section or be adequately flood proofed to an elevation no
lower than two (2) feet above the elevation of the flood of 100-year frequency.
Flood proofing shall be accomplished in accordance with Section 18.66.130 of this
Chapter and shall further include impermeable membranes or materials for floors,
walls, and watertight enclosures for all windows, doors, and all other openings,
and be certified by a registered professional engineer or architect that the flood
proofing methods are adequate to withstand the fbod depths, pressures, velocities,
impact and uplift forces associated with the flood of 100-year frequency;
e. A development proposed for a 100-year flood plain, where surface elevations are
available but no flood way is delineated, may significantly increase flood velocities
or depths or generally alter patterns of flood flow. The Flood Plain Administrator
may require a permit applicant to furnish additional hydraulic data before acting
on a permit application for such a flood plain. The data may include, but is not
limited to, any of the following: I
(I) A hydraulic study documenting probable effect on upstream or downstream
property owners caused by the proposed development; or,
(2) The calculated increase in the lOO-year frequency water surface profile
caused by the proposed development.
Permits for such proposed development may be modified or denied if the
additional information shows that the proposed use would cause an additional
OBOINANCE NO. 1097
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flood hazard to adjacent property or significantly increase flood heights.
A significant increase in flood heights is to be one-half (1/2) foot unless
existing or anticipated development in the area dictates a lesser value of
allowable increase.
Also , 100-year water surface profile data shall be provided for subdivision
proposals and other proposed development which contain at least fifty (50)
lots or five (5) acres (whichever is less);
I f. Mobile home stands on lots are elevated on compacted fill so that the lowest floor
of the mobile home will be two (2) feet above elevation of the 100-year flood.
(1) Adequate surface drainage and access for a hauler are provided.
g. Mobile homes proposed for use as a residential, commercial, or industrial structure
must meet the anchoring requirements of Section 18.66.111, Item 2, of this Chapter.
h. Roads, streets, highways, and rail lines shall be designed to minimize increases
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
(2) feet above the elevation of the flood of 100-year frequency; and
i. Agricultural structures that have a low flood damage potential, such as sheds,
barns, shelters, and hay or grain storage structures must be adequately anchored
to prevent flotation or collapse.
3. Prohibited Uses
The following artifical obstructions and nonconforming uses are prohibited with the
floodway fringe:
a. Solid waste disposal, water distribution systems, and sewage treatment andlor
disposal systems except as allowed or approved under the laws and standards
administered by the Montana Department of Health and Environmental Sciences;
and,
b. Storage of highly toxic, flammable, or explosive materials. Storage of petroleum
products may be allowed by permit if buried in tightly sealed and contained
containers or is stored on compacted fill at least two (2) feet above the elevation
I of the flood of 100-year frequency.
18.66.120 GENERAL STANDARDS
The minimum floodplain development standards listed in this Section apply to the 100-year
flood plains delineated by approximate methods and identified as unnumbered A Zones on
the City of Bozeman Flood Insurance Rate Maps.
l. Uses Allowed Without Permits
All uses allowed in a flood way , according to the provisions of Section 18.66.111, Item 1,
of this Chapter, shall also be allowed without a permit in the flood way fringe.
2. Uses Requiring Permits
All uses allowed in the flood way fringe subject to the issuance of a permit, according
to the provisions of Section 18.66.102, Item 2, shall require permits from the Flood
Plain Administrator for Zone A flood plains. Also, the provisions of Section 18.66.112,
Item 2e, apply to Zone A flood plains with no floodway delineated or water surface
profile computed. Since there are no 100-year frequency water surface profiles
computed for Zone A flood plains, the following conditions also shall apply:
a. Elevation data on the 100-year frequency flood shall be provided for subdivision
proposals and other proposed development which contain at least fifty (50) lots
or five (5) acres (whichever is less) and be utilized in applying Section 18.66.112,
Items 2c and 2d of this Chapter, and;
b. Obtain, review, and reasonably utilize any 100-year flood elevation data available
from a Federal, State or other source, until such data has been provided by the
I Federal Insurance Administration to enforce Section 18.66.112, Items 2c and 2d of
this Chapter, and,
c. Historical flood elevations may be used by, the Flood Plain Administrator in deter-
mining suitable fill or flood proofing elevations to be achieved, and used in
accordance to Section 18.66.112, Items 2c and 2d of this Chapter;
d. If historical flood evidence is not available, then the Flood Plain Administrator
shall determine. from a field review at the nroposed development site. an
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approximate fill and/or flood proofing elevation to be utilized in applying Section
18.66.111, Items 2c and 2d of this Chapter; and
e. Proposed structures must be anchored to prevent flotation or collapse and must
be located as far from stream channels as practical.
3. Prohibited Uses
Those uses prohibited in the fhodway fringe, in accordance with Section 18.66.112, I
Item 3, of this Chapter, shall also be prohibited within the Zone A flood plain
boundaries.
Flood Plain Boundary Interpretation
4.
The Flood Plain Administrator shall make interpretations where needed, as to the exact
location of the Zone A flood plain boundary where there appears to be a conflict
between a mapped boundary and actual field conditions.
18.66.130 FLOOD PROOFING REQUIREMENTS
l. Certification
If the following flood proofing requirements are to be utilized for a proposed structure
as stipulated by the Flood Plain Administrator in accordance with this Chapter, the
methods used must be certified as adequate by a registered professional engineer or
archi tect.
2. Conformance
Permitted flood proof systems shall conform to the conditions below:
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 (2) feet above the elevation
of the flood of 100-year frequency provided that the equipment can be
disconnected by a single plug and socket assembly of the submersible type; I
(2) Portable or movable electrical equipment may be placed below the elevation
of the flood of 100-year frequency provided that the equipment can be
disconnected by a single plug and socket assembly of the submersible type;
(3) The main power service line shall have automatically operated electrical
disconnect equipment or manually operated electrical disconnect equipment
located at an accessible remote location outside the flood plain of 100-year
frequency and above the elevation of the flood of 100-year frequency; and,
(4) All electrical wiring systems installed at or below the elevation of the fhod
of 100-year frequency shall be suitable for continuous submergence and
may not contain fibrous components.
b. Heating Systems
(1) Float operated automatic control valves must be installed in supply lines to
gas furnaces so that the fuel supply is automatically shut off when flood
waters reach the floor level where the furnaces are located;
(2) Manually operated gate valves that can be operated from a location above
the elevation of the flood of 100-year frequency shall also be provided in gas
supply lines; and,
(3) Electrical heating systems must be installed in accordance with the provisions
of Section 18.66.130, Item 2a.
c. Plumbing Systems
(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, I
(2) All toilet stools, sinks, urinals and drains must be located such that the
lowest point of possible water entry is at least two (2) feet above the
eleva tion of the fhod of 1 DO-year frequency.
ORDINANCE NO. 1097
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SECTION 3
This ordinance shall be in full force and effect from and after thirty (30) days after
its adoption.
PASSED, ADOPTED AND APPROVED BY THE CITY COMMISSION of the City of Bozeman,
I Montana, this 3rd day of February 1982.
ALFRED M. STIFF, MA YOR
ATTEST:
ROBIN L. SULLIVAN
Clerk of the City Commission
State of Montana )
County of Gallatin )
Ci ty of Bozeman )
I, Robin L. Sullivan, Clerk of the City Commission of the City of Bozeman, do
hereby certify that the foregoing Ordinance No. 1097. was published in the Bozeman Daily
Chronicle, a newspaper of general circulation printed and published in said City of Bozeman
I in the issue dated the 8th day of February 1982.
IN WITNESS WHEREOF I hereunto set my hand and affix the corporate seal of my
office this 15th day of April 1982.
Cler k of the City Commission
I
ORDINANCE NO. 1097
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