HomeMy WebLinkAboutOrdinance No. 1063
ORDINANCE N0. 1063
AMENDING SECTION 15.48.010 OF THE LAUREL
MUNICIPAL CODE, FLOODPLAIN REGULATIONS
IT IS HEREBY ORDAINED by the City Council of the City of
Laurel, Montana, that Section 15.48.010 of the Laurel Municipal
Code is amended as follows:
Section 15.48.010. Floodplain regulations- purpose.
1. This ordinance is passed in order to comply with
the Montana Floodplain and Floodway Management
Act (Montana Code Annotated Title 76 Chapter 5)
and to insure compliance with the requirements
for the continued participation by the City of
Laurel in the National Flood Insurance Program.
Land use regulations which are hereby adopted
are to be applied to all identified 100 year
floodplains within the City's jurisdiction and
are attached as Exhibit A and fully incorporated
as part of this ordinance by this reference.
2. This ordinance and the attached Exhibit A,
Floodplain Regulations, are adopted under the
authority of Montana Code annotated Title 76,
Chapter 5, part 3.
3. This ordinance adopts the set of comphrehensive
land use regulations attached as Exhibit A for
identified 100 year Floodplains within the City
of Laurel. Identification of 100 year Floodplains
is based on the Federal Emergency Management Agencies
Flood Insurance study for the City of Laurel dated
July 26, 1982, the Flood Insurance rate map, and the
Flood Boundary and Floodway map.
All other Ordinance's are hereby repealed to the extent
that they conflict herewith.
Introduced at a regular meeting of the City Council on
this 5th day of January 1993, by Alderman Kilpatrick
PASSED and ADOPTED .by the City Council of the City of
Laurel, Montana, this 19th day of January 1993.
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APPROVED by the Mayor this :20th day of Januar
1993.
City of Laurel
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Charles G. Rod ers Mayor
~ST:
Donal ackmann, City Clerk
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(revised 1/9/90)
(amended 2-25-91)
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FLOODPLAIN AND FLOODWAY MANAGEMENT ORDINANCE
FOR COMMUNITIES WITH DESIGNATED FLOODWAYS
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TABLE OF CONTENTS
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Page
Intent ................................................................................101
Statutory Authority ....................................................................101
Adoption .............................................................................101
L 15t1e and Purpose ...................................................................102
II, DetSnitions .........................................................................103
III. General Provisions ................................................................106
3.01 Jurisdictional Area ............................................................. 106
3.02 Floodplain District Establishment ................................................. 106
3.03 Floodplain Administrator ........................................................106
3.04 Rule for Interpretation of Floodplain District Boundaries ............................. 106
3.05 Compliance ....................................................................106
3.06 Abrogation and Greater Responsibility . ............................................ 106
3.07 Regulation Interpretation ........................................................106
3.08 Warning and Disclaimer of Liability ............................................... 107
3.09 Severability ...................................................................107
3.10 Disclosure Provision ............................................................ 107
• IV. Administration ....................................................................108
4.01 Administration ................................................................108
4.02 Permit Applications ............................................................109
4.03 Emergency Waiver .............................................................110
4.04 Review-Variance- Appeals ..................................................... 111
4.05 Fees .........................................................................112
4.06 Violation Notice ............................................................... 112
4.07 Compliance ...................................................................112
4.08 Penalties .....................................................................112
4.09 Emergency Preparedness Planning ............................................... 112
V. Specific Standards .............. ...................................................113
5.01 Applications ...................................................................113
5.02 Floodway ................................
A Uses Allowed Without Permits....... .
B. Uses Requiring Permits ............. .
C. Permits for Flood Control Works...... .
D. Permits for Water Diversions ........ .
E. Prohibited Uses ................... .
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5.03 Floodway Fringe ...............................................................117
• A Uses Allowed Without Permits .............................................117
B. Uses Requiring Permits ...................................................117
C. Prohibited Uses .........................................................118
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5.04 Floodplain Areas with Flood Elevations and No Delineated Floodway .................... 118
5.05 Shallow Flooding (AO Zones) ..................................................... 119
Vl. General Standards ................................................................120
6.01 Applications ...................................................................120
A Uses Allowed Without Permits .............................................120
B. Uses Requiring Permits ...................................................120
C. Prohibited Uses .........................................................120
D. Floodplain Boundary Interpretation .........................................120
VII. Flood-proofing Requirements ......................................................121
7.01 Certification ...................................................................121
7.02 Conformapce ..................................................................121
A Electrical Systems .......................................................121
B. Heating Systems ........................................................121
C. Plumbing Systems ....................................................... 121
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CHAPTER II
DEFDVITION3
2.01 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 roason-
able application.
ACL -Montana Floodplain and Floodway Management Act, X76-5-101 through 406, MCA.
Alteration -Any change or addition to a structure that either increases its external dimensions or
increases its potential flood hazard.
Ap~,Sl - A request for a review of the Floodplain Administrator's interpretation of any provisions of
these regulations or a request for a variance.
Ar „ of Special Flood H ward -The land in the floodplain within the community subject to inunda-
tion by a one percent (1%) or greater chance of flooding in any given year, i.e., the 100-year flood-
plain.
Artifici 1 Obs . , .;on - D v lonm n . -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 analo-
gous structure or matter in, along, across, or projecting into any 100.year floodplain which may im-
pede, 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 down-
stream to the damage or detriment of either life or property.
•~ Base Flood - A flood having a one percent (1%) chance of being equalled or exceeded in any given
year. Abase flood is the same as a 100.year flood.
Base Flood F.leva .ion -The elevation above sea level of the base flood in relation to National Geo-
detic Vertical Datum of 1929 unless otherwise specified in the flood hazard study.
Ch nn .li ation Projer -The excavation and/or construction of an artificial channel for the purpose
of diverting the entire flow of a stream from its established course.
F'i51S}d1811- To construct, place, insert, or excavate.
F.xic+;ne Mam,fac+. ,r d Hom Park or S ,bdi~r ion -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 installa-
tion of utilities, the construction of streets, and either final site grading or the pouring of concrete
pads.
FEMA -The Federal Emergency Management Agency
Flood or Flooding - A general and temporary condition of partial or complete inundation of nor-
mally dry lands from the overflow of a stream, or the unusual and rapid accumulation or runoff of
surface waters from any source.
Flood Ina ,ran RA+p Man -The map on which FEMA has delineated both the 100 year floodplains
and the risk premium zones.
• Flood Ina ,ran t„dv -The report in which FEMA has provided flood profiles, as well as the Flood
Boundary/Floodway Map and the water surface profiles.
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Floodnlain -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.
Eloodwav -The channel of a stream and the adjacent overbank areas that must be reserved in or-
der to discharge a base flood without cumulatively increasing the water surface elevation more than
one-half (1/2) foot.
Floodwav Frinee -That portion of the floodplain outside the limits of the floodway.
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.
Levee System - A flood protection system that consists of a levee, or levees, and associated struc-
tures, such as drainage and closure devices, which are constructed and operated in accordance with
sound engineering practices.
Lowest Floor -Any floor used for living purposes, storage, or recreation. This includes any floor
that could be converted to such a use.
Manufactured Home - A structure that is transportable in one or more sections, built on a perma-
nent chassis, and designed to be used with or without a permanent foundation when connected to the
required utilities. This does not include `4ecreational vehicles."
Manufactured Home Park or Subdivision - A parcel or contiguous parcels of land divided into two
or more manufactured home lots for rent or sale.
Mean Sea Level -The National Geodetic Vertical Datum (NGVD) of 1929 or other datum to which ;•
base flood elevations are referenced.
New Construction -Structures for which construction, substantial improvement, or alteration com-
mences on or after the effective date of these regulations.
Official Floodplain Mans -The Flood Insurance Rate Maps and Flood Boundary\Floodway Maps
provided by FEMA for Laurel, Montana dated
(City, Town or County Name)
Permit Issuing Authority - Laurel , Montana
(City/Pown CounciUCounty Commissioners)
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) designed to be self-propelled or permanently
towable 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.
]tinran -Stone, rocks, concrete blocks, or analogous material that is placed along the banks or bed
of a stream to alleviate erosion.
Start of Construction -Commencement of clearing, grading, filling, or excavating to prepare a site
for construction.
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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~'nbatantial Daman -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.
C ,h ential Imorov m n --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.
The term does not include:
(i} 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
(ii) any alteration of a structure listed on the national register of historic places or state
inventory of historic places.
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.
Vari n e - A grant of relief from the requirements of these regulations that would permit construc-
tion in a manner otherwise prohibited by these regulations.
Violation -The failure of a structure or other development to be fully compliant with these regula-
. tions. A structure or other development without elevation certificate, certification by a licensed engi-
neer 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.
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-
yearflood is the same as a base flood.
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GENERAL PROVISIONS
3.01 .T +ri di .ional ma
These regulations shall apply to all lands within the jurisdiction of r.a ~rP~ . M ntana
(City, Town or County Name)
Stateof Montana, shown on the Official Floodplain Mape as being located within a 100-year flood-
plain district.
3.02 Flno main District F.sta_hlishment
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 Fleod Insurance Study is a scientific
and engineering report entitled, 'fihe Flood Insurance Study for Laurel ,Montana,"
dated .with accompanying Flood Insurance Rate Maps and Flood Boundary/
Floodway Mape. The Official Floodplain Maps and Study are on file in the office of the Floodplain
Administrator.
3.03
The Laurel, Montana Floodplain Administrator
(City, Town, or County Name)
has been designated to be the
(Title of Floodplain Administrator)
The responsibilities of this position are outlined in Chapter IV of these regulations.
3.04 Rules for Interpretation of Floodplain District Boundaries
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 maybe used as a guide far 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. For unnumbered A Zones and AO Zone floodplains, where there is a conflict be-
tween amapped floodplain boundary and actual field conditions, the Floodplain Administrator may
interpret the location of the 100-year floodplain boundary based on field conditions or available his
torical flood information.
3.06 Cmm~liance
No structure or land use shall be located, extended, converted, or structurally altered without full
compliance with the pmviaions of these regulations and other applicable regulations. These regula-
tiona meet the minimum floodplain development requirements as set forth by the Montana Board of
Natural Resources and Conservation and the National Flood Insurance Program.
3.06 Ahro¢ation and (=rester Responsibility
It is not intended by these regulations to repeal, abrogate, or impair any existing easements, cov-
enants, deed restrictions, or underlying zoning. However, where these regulations impose greater
restrictions, the provisions of these regulations shall prevail.
3.07 Re¢ulation Interoretation
The interpretation and application of the provisions of these regulations shall be considered mini-
mum requirements and liberally construed in favor of the governing body and not deemed a limita-
tion or repeal of any other powers granted by State statute.
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3.08 W rnin~ and Dis laim r of T.iahility
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 cre-
ate aliability or cause of action against Laurel . Montana
(City, Town, or County Name)
or any officer or employee thereof for flood damages that may result from reliance upon these rogula-
tiona.
3.08 RevPrability
If any section, clause, provision, or portion of these regulations is adjudged unconstitutional or in-
valid by a court of competent jurisdiction, the remainder of these regulations shall not be affected
thereby.
s.lo T~IRC108Lrq prOVlsiOL
All owners of property in an identified 100-year floodplain as indicated on the Official F7oodplain
Maps must notify potential buyers or their agents that such property ie subject to the pravisiona of
these regulations.
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CAAPTF.R.IV
ADMINISTRATION
4.01
A Aa provided in Section 3.03 of these regulations, the Floodplain Administrator has been designated
by the Laurel . Montana .and has the responsibility of such position as outlined
(City/Pown Council/County Commissioner)
in these regulations.
B. The Floodplain Administrator is hereby appointed with the authority to review floodplain develop-
ment permit applications, proposed uses, and construction to determine compliance with these regu-
lations. The Floodphun 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.
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 regula-
tions. 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 maybe 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 de-
velopment in the foreseeable future;
the relationship of the proposed use to the comprehensive plan and floodplain man-
agement program for the area;
j. the safety of access to property in times of flooding for ordinary and emergency ser-
vices; and
k. such other factors as are in harmony with the purposes of these regulations, the Mon-
tana Floodplain and Floodway Management Act, and the National Flood Insurance
Program.
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C. A floodplain development permit application is considered to have been automatically granted 60
days after the date of receipt of the application by the Floodplain Administrator unless the applicant
has been notified that the permit is denied, conditionally approved, or additional information perti-
nent 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 docu-
mentnonconforming uses, base flood elevations, floodproofing and elevation certifications, fee re-
ceipts, the issuance of permits, agenda, minutes, records of public meetings, and any other matters
related to floodplain managementin Laurel, Montana .Such files and records
(City, Town, or County)
shall be open for public inspection. In matters of litigation, the T~aurel . Montana
(City, Town, or County)
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 regirements 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 Conserva-
tion in Helena, Montana
I. In riverine situations, notification by the Floodplain Administrator must be made to adjacent cem-
munitiea, the Floodplain Management Section (DNRC), and FEMA prior to any alteration or reloca-
tion 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.
4.02 p .rmi . ~linatione
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 Flood-
plain 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.
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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 offlood-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 sub-
stantially improved buildings.
2. Ifflood-proofing techniques were used for buildings, the mean sea level elevation to which
the flood 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 submit-
ted with the application for the permit activity. This certification maybe waived 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 offlood-proofing and/or elevation shall be provided on a standard form available
from the floodplain administrator.
4.03 F.m ._w nev Wai .r
A Emergency repair and replacement of severely damaged public transportation facilities, public water
and sewer facilities, and flood control works maybe authorized. Floodplain development permit
requirements may be waived if:
1. Upon notification and prior to the emergency repair and/or replacement, the Floodplain Ad-
ministrator determines that an emergency condition exists warranting immediate action;
and
2. The F7oodplain 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 emer-
gencycondition, and the type of emergency work agreed upon, and stating that a verbal authoriza-
tionhad been previously given.
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4.04 RPView-Variances•Apneals
~A. There is hereby created a local Floodplain Management Board of Adjustment, the membership, ad-
ministration, 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 mini-
mum standards contained in these regulations according to the following procedures:
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 haz-
ards, 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 maybe attached;
b. the issuance of a variance to construct a building below the 100-year floodplain eleva-
tion will result in increased premium rates; and
c. such construction below the 100-year flood elevation increases risks to life and prop-
erty. The Floodplain Administrator shall maintain records of the variance notifica-
tion and actions, including justification for 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 persona, jointly or separately, to a court of record.
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4.05 Fees
A processing fee of shall be submitted with each permit application.
4.06 Violation Notice
The Floodplain Administrator shall bring any violation of these regulations to the attention of the
local governing body; its legal council; and and the Montana Department of Natural Resources and
Conservation.
4.07 Comnlian . .
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 4.08. 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 eleva-
tions, flood proofing, hydraulic design, or other flood protection measures were accomplished in com-
pliance with these regulations.
4.08 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 fta requirements shall, upon conviction, be fined not more than $100 or impris-
oned 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.
4.09 Emer¢enev Preparedness Plannin¢
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 approved by appropriate community
emergency management authorities.
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(',AAPTF.R V
SPECIFIC STANDARDS
5.01 Applications
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 Mapa.
6.02 Ejnodwav
A. j,jges Allowed WithoLt Permits. The following open-space uses shall be allowed without a permit
within the floodway, provided that such uses conform to the provisions of Chapter VII of these regu-
lations; are not prohibited by any other ordinance, resolution, or statute; and do not require fill, exca-
vation, 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 security devices, and has no permanently attached addi-
tions.
B. Uses ltaau;ring P rmi .s, The following artificial obstructions may be permitted in the floodway sub-
ject 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.
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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 sus-
pendedline 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
c. utility transmission lines carrying toxic or flammable materials are buried to a depth
of at least twice the calculated maximum depth of scour fora 100.year flood. The
maximum depth of scour shall be determined by hydraulic engineering methods ac-
ceptable to the Floodplain Administrator.
5. Storage of materials and equipment, provided that:
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 pampa, 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 loca-
tions.
Buried and sealed vaults for sewage disposal in recreational areas, provided they meet appli-
cable laws and standards administered by the Montana Department of Health and Environ-
mental Sciences.
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- i •
S. 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 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;
a the structures will, insofar as possible, be located on ground higher than the sur-
roundingground and as far from the channel as possible;
d. the flood-proofing standards of Chapter VII 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. Substantial improvements to any structure provided that the provisions of Section 5.03-B.3
,
5.03-B.4, or 5.03-B.5 of these regulations are met. In the floodway the structure moat be
floodproofed or elevated on a permanent foundation rather than on fill.
11. All other artificial obstructions, substantial improvements, ornon-conforming uses not spe-
cifically listed or prohibited by these regulations.
C. Perm ;te 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 100-
yearflood; 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 con-
strutted at ]east 3 feet higher than the base flood elevation.
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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
Bite.
3. Channelization projects if they do not significantly increase the magnitude, velocity, or base
flood elevation in the proximity of the project.
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 proce-
dures or improper hydrologic/hydraulic design.
D.
E.
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 de-
signed and constructed to safely withstand a 100-year flood.
prohibited Usea. The following artificial obstructions and non-conforming uses are prohibited within
the floodway:
1. New construction of any residential, commercial, or industrial structure;
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;
7. Manufactured homes.
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5.03 Flondwav FrinQ'e
.A LTa llow d Wi .hou . P rmits, All uses allowed in the floodway, according to the provisions of Sec-
tion 5.02 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. i ar ~aniring P rmi a, A11 uses allowed in the floodway subject to the issuance of a permit, accord-
ing to the provisions of Section 5.02 B, C, and D of these regulations, shall also be allowed by permit
within the floodway fringe. In addition, new construction, substantial improvements, and alter-
ations to structures are allowed by permit. This includes but is not limited to residential, commer-
cial, and industrial construction and suitable fill to be allowed by permit from the Floodplain Admin-
istrator, 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 r aid .n .iel c . . ~ a
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 suit-
able 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 .omr m r ia1 and j~jSl
atn±c*~ra=can be constructed on suitable fill as specified in Section 5.03-B.3 of these regula-
tions. 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-
proofingmust be certified by a registered professional engineer or architect that the flood-
proofingmethods are adequate to withstand the flood depths, hydrodynamic and hydrostatic
pressures, velocities, impact, buoyancy, and uplift forces associated with the 100-year flood.
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 stor-
age 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 de-
signed to automatically equalize hydrostatic forces by allowing for entry and exit of
floodwaters. Openings may be equipped with screens, louvres, valves, other cover-
ings, 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 im-
permeable 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.
G Flood-proofing of electrical, heating, and plumbing systems shall be accomplished in
accordance with Chapter VII of these regulations.
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5. All manufactured homes placed in the floodway fringe must have the chassis securely an-
chored 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 permanentfoundation of reinforced concrete, reinforcedmortsred block,
reinforced piers, or other foundation elements of at least equivalent strength.
b. Replacement or subatantiel improvement of manufactured homes in an existing
manufactured home park or subdivision moat be raised on a permanent foundation.
The lowest floor must be two feet above the base flood elevation. The foundation
must consist of reinforced concrete,reinforcedmortared block,reinforcedpie:s, or
other foundation elements of at least equivalent strength.
c. Manufactured )fig proposed for use ae 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 eleva-
tion;
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 5.03-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 anchored to a permanent foundation to prevent downstream movement.
6.04 Flnndnlain Areas with Flood Elevations and No Delineated Floodwav
A. A development proposed fora 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 5.03, Fooodway Fringe, shall apply to these areas.
The Floodplain Administrator may require a permit applicant to famish 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: •
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1. a hydraulic study documenting probable effect on upstream, downstream, or adjacent prop-
erty 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 signifi-
cantlyincrease flood heights. A significant increase in flood heights isone-half foot unless e~dsting
or anticipated development in the area dictates a lesser amount of allowable increase.
fi.0fi Shallow Floodin¢ (AO nn .a1
A Shallow flooding areas are delineated as AO Zone floodplains on the Flood Insurance Rate Maps.
The provisions of Section 5.03, Floodway Fringe, of these regulations shall apply to any AO Zane
floodplains. The depth of the 100-year flood is indicated as the depth number on the Flood Insurance
Rate Maps. The 100-year flood depth shall be referenced to the highest adjacent grade or stream
flow line in determining which fill orflood-proofing heights to use in applying the provisions of Sec-
tion 5.03-B.3 and Section 5.03-B.4 of these regulations. In the absence of depth or elevation informa-
tion, aminimum 2 foot flood depth shall be used.
B. ~oodpla;n Bo ,Lndarv In . ror .a .+oo_ The Floodplain Administrator shall make interpretations
where needed as to the enact location of an AO Zone floodplain boundary when there is a conflict
between a mapped boundary and actual field conditions.
•
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CFIAPTER VI
GENERAL STANDARDS
6.01 A~lications •
The minimum floodplain development standards listed in this chapter apply to the 100-year flood-
plains delineated by approximate methods and identified as unnumbered A Zones on the Flood In-
surance Rate Mape.
A. Uses Allowed Without Permits. All uses allowed in a floodway, according to the provisions of Section
5.02-A of these regulations, shall also be allowed without a permit in unnumbered A-Zone flood-
plains.
B. s s .grinQ Permits. All uses allowed in the floodway and floodway fringe subject to the issu-
ance of a permit, according to the provisions of Section 5.03-B, shall require permits from the Flood-
plain Administrator for unnumbered A-Zone floodplains. Alsa, the provisions of Section 5.03-B apply
to the A Zone floodplains with no floodway delineated or water surface profile computed. Since there
are no lOp-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, MCA 76-4 Part 1
and the rules adopted by DHSS under this Act. These data shall be used in applying Sec-
tions 5.03-B.3, 5.03-B.4, and 5.03-B.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 eleva-
tion and floodway data available from federal, state, or other sources, until such data have
been provided by FEMA, to enforce Section 5.03-B.3 and 5.03-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 5.03-B.3 and 5.03-B.4 of these regulations;
4. If historical flood evidence is not available, then the Floodplain Administrator shall deter-
mine, from a faeld review at the proposed development site, an appropriate fill or flood-proof
ing etevation to use in applying Sections 5.03-B.3 and 5.03-B.4 of these regulations. In the
absence of depth or elevation information, a minimum two-foot flood depth shall be used; and
5. Proposed structures must be anchored to prevent floatation or collapse and must be located
as far from stream channels as practicable.
C. Prohibi pd is ,Those uses prohibited in the floodway fringe, in accordance with Section 5.03-C of
these regulations, shall also be prohibited within the A-Zone floodplain boundaries.
D. Floodnlain Boundary Interpretation. 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.
C~
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(',AAPTF.R V I
FLOOD-PROOFING REQUIREMENTS
7.01 rtifica .ion
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.
7.02 Conformance
Permitted flood-proof systems shall conform to the conditions liatedbelow-and the flood-proofing
standards listed in Section 5.03-B.4 of these regulations for commercial and industrial structures.
A F.lectrica] 4ys ems
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 100-year floodplain and above the
base flood elevation; and
4. All electrical wiring systems installed at or below the elevation of the 100-year flood shall be
suitable for continous submergence and may not contain fibrous components.
• B. H -a .i v . ma
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 7.02-
A.
C. P1LmbingyCys m
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.
121