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RES 1986-08 FLOODPLAIN ACT r / RESOLUTION NO. Intent This resolution is passed in order to comply with the Montana Floodplain and Floodway Management Act (Chapter 5, Title 76- M.C.A.) and to ensure compliance with the requirements for the continued participation by Jefferson County in the National Flood Insurance Program. Land -use regulations which are hereby adopted are to be applied to all identified 100 -year floodplains within Jefferson County and are attached as Appendix A. Statutory Authority Floodplain and Floodway Management Act, 76 -5 MCA allows counties to adopt land use regulations for floodplains designated by the Board of Natural Resources and Conservation. County Planning and Zoning, Title 76 -2 MCA authorizes counties to adopt land -use regulations to protect the health, safety and welfare of constituents. Adoption This Resolution adopts the set of comprehensive land -use regulations attached as Appendix A for identified 100 -year floodplains within Jefferson County. Identification of 100 -year floodplains is based on the Big Pipestone Creek Floodplain Management Study, dated September 1984 and Jefferson County Flood Hazard Boundary Maps dated June 17, 1986. All other resolutions are hereby repealed to the extent of the inconsistency only. y 1 ATTEST: 1� 11 t.�_, 1. By: Clerk & Recor er I Douglas K. sc itz, Chairman Jeffers n County Board of C66missioners APPENDIX A CHAPTER I TITLE AND PURPOSE 1.01 Title These Regulations shall be known and cited as Jefferson County Floodplain Regulations. These Regulations are in accordance with exercising the authority of the laws of the State of Montana. 1.02 Purpose To promote the public health, safety, and general welfare, to minimize flood losses in areas subject to flood hazards, and to promote wise use of the floodplain. These Regulations have been established with the following purposes intended: 2 S a A. To guide development of the 100 -year floodplain areas of Jefferson Coubty consistent with the enumerated findings by: 1. recognizing the right and need of water courses to periodically carry more than the normal flow of water; 2. participating in coordinating efforts of federal, state and local management activities for 100 -year floodplains; and, 3. insuring the regulations and minimun standards adopted, insofar as possible, balance the greatest public good with the least private injury. B. Specifically it is the purpose of these Regulations to: 1. restrict or prohibit uses which are dangerous to health, safety or property in times of flood, or cause increased flood heights or velocities; 2. require that uses vulnerable to floods, including public facilities which serve such uses, be provided with flood protection at the time of initial construction; 3 3. utilize information which identifies lands which are unsuited for certain development purposes because of flood hazardsl 4. minimize the need for rescue and relief efforts associated with flooding and generally undertaken at the expense of the general public; S. insure that potential buyers are notified that property is within a 100 -year floodplain and subject to the provisions of these Regulationsl and, 6. insure that those who occupy 100 -year floodplains assume responsibility for their actions. 4 CHAPTER II DEFINITIONS 2.01 12efinitions Unless specifically defined below, words or phrases used in these Regulations shall be interpreted so as to give them the meaning they have in common usage and to give these Regulations their most reasonable application. Alteration - Any change or addition to a structure that increases its external dimensions. 8gRl, - A request for a review of the interpretation of the Floodplain Administrator of any provision of these Regulations a request for a variance. Area of Special Flood Hazard - The land in the floodplain within the community subject to inundation by a one percent (1%) or greater chance of flood in any given year, i.e. the 100 -year Floodplain. 5 Ae C Arti icial Ob truction - Develop )ment - Any obstruction which is not natural and includes any dam, diversion, wall, riprap, embankment, levee, dike, pile, abutment, projection, revetment, excavation, channel rectification, bridge, conduit, culvert, building, refuse, automobile body, fill or other analogous structure or matter in, along, across or projecting into any 100 -year floodplain which may impede, retard or alter the pattern of flow of water, either in itself or by catching or collecting debris carried by the water, or that is placed where the natural flow of water would carry the same downstream to the damage or detriment of either life or property. Base Flood - A flood having a one percent (1 %) chance of being equalled or exceeded in any given year. hannelization 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. stablish - To construct, place, insert or excavate. 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 of surface waters from any source. 6 Floodplain - The areas adjoining a stream which would be covered by floodwater. Floodwav 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. F ;rrinae - That portion of the floodplain outside the limits of the floodway. Flood Insurance state Map - The map on which the Federal Insurance Administration has delineated both the 100 -year floodplains and the risk premium zones. 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. Lowest Floor Elevation - Any floor usable, or that could be converted to a use, for living purposes, storage or recreation. Mobile Home - A structure that is transportable in one or more sections, built on a permanent chassis and designed to 7 be used with or without a permanent foundation when connected to the required utilities. It does not include recreational vehicles or travel trailers. ]34161 Constry -ction - Structures for which the start of construction, substantial improvement or alteration commences on or after the effective date of these Regulations. ]ion- Conforming - 11gg - A land use not in accordance with these Regulations. Official Floodplain JAps - The Flood Insurance Rate Maps and provided by the Federal Insurance Administration for T _ff _rSnn County dat June 17 - 1986 and Big Pipestone Creek Floodplain Management Study dated September 1984 provided by the Soil Conservation Service. Permit Issuing Authority - Jefferson County Q mmc� iaajg a rs Rinran - Stone, rocks, concrete blocks or analogous material that is placed along the banks or bed of a stream for the purpose of alleviating erosion. Stan ,gf Construction The first placement of permanent construction of a structure (other than a mooile home) on a site, such as pouring of slabs or footings or any work beyond 8 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 walkwayal nor does it include the excavation for a basement, footings, piers or foundation or the erection of temporary formsf 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 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 subdivision, 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 (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. Structure - A walled and roofed building, mobile home, or a gas or liquid storage tank, that is principally above ground. 9 SubatAntiAl Im rooygent - Any repair, reconstruction, or improvement of a structure, the cost of which equals or exceeds fifty percent (50 %) of the market value of the structure either: (1) before the improvement or repair is started, or (2) if the structure has been damaged, and is being restored, before the damage occurred. For the purposes of this definition, substantial improvement is considered to occur when the first construction to any wall, ceiling, floor or other structural part of the building commences. A substantial improvement differs from the alteration of a structure in that it is not dearined 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 soley 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. 10 c ' 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. Va�iancg - A grant or relief from the requirements of these Regulations which would permit construction in a manner that would otherwise be prohibited by these Regulations. CHAPTER III GENERAL PROVISIONS 3.01 jurisdictional Area These Regulations shall apply to all lands within the jurisdiction of Jeffer .qc5n C`nnnty , State of Montana, shown on the Official Floodplain Maps as being located within a 100 -year floodplain district. 11 1 I 3.02 Floodplain District Establishment The floodplain districts established are defined by the 100 -year floodplains as delineated in the Big Pipestone Creek Floodplain Management Study and by the Flood Insurance Rate Maps. The Official Floodplain Maps, together with the Floodplain Management Study are on file in the Office of the Jefferson County Floodplain Administrator. 3.03 Floodplain Administrator The Jefferson County Floodplain Administrator has been designated to be the Jefferson County Sanitarian . 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 floodplain and floodway shall be determined by scaling distances on the Official Floodplain Maps. Where there appears to be a conflict between a mapped floodplain boundary and actual field conditions, 12 the Jefferson County Administrator may determine that the area is not to be included within the 100 -year floodplain. The property owner or developer WoHld then not have to satisfy the provisions of these Regulations. 3.05 Compliance No structure or land use shall be located, extended, converted or structurally altered without full compliance with the provisions of these Regulations and other applicable regulations. These Regulations meet the minimum floodplain development requirements as set forth by the Montana Board of Natural Resources and Conservation and in the National Flood Insurance Program regulations. 3.06 A brogation and Greater Responsibility It is not intended by these Regulations to repeal,, abrogate or impair any existing easements, covenants, deed restrictions or underlying zoning. However, where these Regulations impose greater restrictions, the provisions of these Regulations shall prevail. 13 7 3.07 Regulation Tnte nratatign In their interpretation and application, the provisions of these Regulations 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. 3.08 NjIgning and ]2iggJaimer of iabklity These Regulations do not imply that areas outside the delineated floodplain boundaries or permitted land uses within such areas will always be totally free from flooding or flood damages. These regulations shall not create a liability on the part of, or a cause of action against Jefferson County , or any officer or employee thereof for any flood damages that may result from reliance upon these Regulations. 3.09 Severability If any section, clause, provision or portion of these Regulations is adjudged unconstitutional or invalid by a court of competent jurisdiction, the remainder of these Regulations shall not be affected thereby. 14 3.10 Digg o ure Provision All owners of property in an identified 100 -year floodplain as indicated on the Official Floodplain Maps must notify potential buyers or their agents that such property is subject to the provisions of these Regulations. Upon resale of property, the lending institution must notify potential buyers ten 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. CHAPTER N Administration 4.01 Administration A. As provided in Section 3.03 of these Regulations, the JgfZerson _Caunfy Floodplain Administrator has been designated by the Jefferson County Commissioners___ and has the responsibility of such position as outlined in these Regulations. 15 r, B. The Floodplain Administrator is hereby appointed with the authority to review floodplain development permit applications and proposed uses or construction to determine compliance with these Regulations, 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 U.S.C. 1334. 1. Additional Factors W 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 or non - conforming use meets the requirements of these Regulations. Additional factors that shall be considered for every permit application are: a, the danger to life and property due to increased flood heights, increased flood water velocities or alterations in the pattern of flood flow caused by encroachments; b. the 4anger that materials may be swept onto other lands or downstream to the injury of others; 16 r Y 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 water -front location; g* the availability of alternative locations not subject to flooding for the proposed use; h. the compatibility of the proposed use with existing development and anticipated development in the foreseeable future; i. the relationship of the proposed use to the comprehensive plan and floodplain management for the area; 17 j. the safety of access to property in times of flooding for ordinary and emergency services; and, k. such other factors as are in harmony with the purposes of these Regulations, the Montana Floodplain and Floodway Management Act and the National Flood Insurance Program. C. A floodplain development permit application is considered to have been automatically granted 60 days after the date of receipt of the application by the Floodplain Administrator, unless the applicant has been notified that the permit is denied, conditionally approved or additional information pertinent to the permit review process is required. D. The Floodplain Administrator shall adopt such administrative procedures as may be necessary to efficiently administer the provision of these Regulations. E. The Floodplain Administrator shall maintain such files and records as may be necessary to document nonconforming uses, flood elevations, fee receipts, the issuance of permits, agendas, minutes, records of public meetings, and any other matters related to Floodplain management in Jefferson County shah files and records shall be open for public inspection. In matters of 18 litigation, Jefferson County Attorney may restrict access to specific records. F. Copies of k1l permits granted must be sent to the Department of Natural Resources and Conservation in Helena, Montana. G. In riverine situations, notification by the Floodplain Administrator must be made to adjacent communities, the Floodplain 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. 4.02 Pprmit ApJ21igati A. 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 Floodplain Administrator. B. Permit applicants may be required to furnish such of the following as is deemed necessary by the Floodplain Administrator for determining the suitability of the particular site for the proposed use: 19 1. 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 sites, flood -- proofing measures, first floor of proposed structures in mean sea level elevation and location of the channel; 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, site plan and /or construction plans; and, 3. Specifications for flood - proofing, filling, excavating, grading, riprapping, storage of materials and utilities location. C. Applicants who have received permits are required to furnish the following, at the time of an on --site conformance inspection, for determining that the permit specifications and conditions have been complied with: 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 20 all new, altered or substantially improved structures. 2. If flood - proofing techiques were utilized for the above described structures, then the mean sea level elevation to which the flood proofing was accomplished must be similarity certified. 4.03 ergency Waiver A. 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 Floodplain development permit requirements waived if: 1. upon.notification and prior to the emergency repair and /or replacement, the Floodplain Administrator determines that an emergency condition warranting immediate action exists; and 2. the Floodplain Administrator agrees upon the nature and type of. proposed emergency repair and /or replacement. B. Authorization to undertake emergency repair and /or 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 stating the 21 emergency condition, the type of emergency work agreed upon, and a notation that a verbal authorization had been previously given. 4.04 Review - Variances- Appeals A. There is hereby created a _ Floodplai management Board of Adjustment, the membership, administration and rules of procedure of which are identical to and the same as the Planning a nd Zo ning Board of Adjustment. B. The - County Commissioners may, by variance, grant a permit that is not in compliance with the minimum standards contained in these Regulations according to the following procedures: 1. Variances shall not be issued for areas within a floodway if any increase in flood elevations or velocities would result; 2. Variances shall only be issued upon: a. a showing of good and sufficient causer b. a determiniation that refusal of a permit would, because of exceptional circumstances, cause a unique or undue hardship on the applicant or community involved; 22 i c. a determination that the granting of a variance will not result in increased flood heights, present additional threats to public safety be an extraordinary public expense, create 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 floodplain is not available; f. a determination that the variance requested is the minimum necessary, considering the flood hazard, to afford relief; and g. approval of the Montana Department of Natural Resources and Conservation, upon request from the County c , prior to formally approving any permit application which is in variation to these Regulations. 3. Variances shall.be issued in writing from the and shall notify the applicant that: 23 a. a'specific variance is granted, and that certain conditions may be attached, b. the issuance of a variance to construct a structure below the 100 -year floodplain elevation will result in increased premium rates for flood insurance up to amounts as high as $25 for $100 of insurance coverage; and C, such construction below the 100 -year flood elevation increases risks to life and property. The Floodplain 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. C. Appeals of any decision of the County Commissioners or its officers or agencies may be taken by an aggrieved person or persons, jointly or separately, to a court of record. 4.05 fees A processing fee of $25.00 - shall be submitted with each permit application. 24 a � 4.06 Violati n Xgtice The Floodplain Administrator shall bring any violation of these Regulations to the Attention of Jefferson County Commissioners , the Jefferson County Attorney and the Montana Department of Natural Resources and Conservation. 4.07 Qmplfance Any use, arrangement or construction not in compliance with that authorized shall be deemed a violation of these Regulations and punishable as provides in Section 4.08. An applicant may be required to submit certification by a registered professional engineer, architect or other qualified person designated by the Floodplain Administrator that finished fill and building floor elevations, flood proofing or other flood protection measures were accomplished in compliance 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 floodprone lands and conditions and safeguards established in connection with 25 variances, shall consititute a misdemeanor. Any person who violates these Regulations or fails to comply with any of its requirements shall, upon conviction thereof, be fined not more than $100 or be imprisoned in jail for not more that 10 days or be both so fined and imprisoned. Each day's continuance of a violation shall be deemed a separate and distinct offense. CHAPTER V Specific Standards 5.01 Application The minimum floodplain development standards listed in this chapter apply to the floodway / floodway fringe portions of the 100 -year floodplain as delineated on the maps in the Big, Pipestone Creek Fl oodplain Management` "Study. 26 5.02 Flood., A. Uses A Without Permits. The following open space uses shall be allowed without a permit anywhere within the floodway, provided that such uses conform to the provisions of Chapter VII of these Regulations, are not prohibited by any other ordinance, resolution or statute and do not require fill, excavation, permanent storage of materials or equipment or structures other than portable structures; 1. Agricultural uses; 2. Accessory uses such as loading or parking areas, or emergency landing strips associate with industrial - 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 projects with portable equipment; 27 r 7, 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; and 7. Fences, except permanent fences crossing channels. B. lIggs Requiring Permits The following artificial obstructions and non - conforming uses may be permitted in the floodway subject to the issuance of a permit by the Floodplain Administrator: 1. Excavation of material from the pits and pools provided that: a. a buffer strip of undisturbeu 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; b. the excavation meets all applicable laws and regulations of other local and state agencies; and, 28 c. excavated material is stockpiled outside the floodway. 2. Railroad, highway and street stream crossings provided the crossings are designed to offer minimal obstruction to flood flow. 3. Limited filling for highway, street and railroad embankments not associated with stream crossings, provided that: a. reasonable alternative transportation routes outside the designated floodway are not available; and b. such floodway encroachment is located as far from the stream channel as possible.. 4. Buried or suspended utility transimission lines, provided that: 29 f T. a. suspended utility transmission lines are designed such that the lowest point of the suspended line is at least 6 feet higher than the elevation of the flood of 100 -year frequency; b. towers and other appurtenant structures are designed and placed to withstand and offer minimal obstruction to flood flows; and, c. utility transmission lines carrying toxic or flammable materials are buried to a depth at least twice the calculated maximum depth of scour for a flood of 100 -year frequence. 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 F'loodplain Administrator. 5. Storage of materials and equipment, provideu tnat: a. the material or equipment is not subject to major damage by flooding and is properly anchored to prevent flotation or downstream movement; or, b. the material or equipment is readily removable within the limited time available after flood warning. Storage of flammable, toxic or exp! ,, -) i; materials shall not be permitted. 30 6. Domestic water supply wells, provided that: a. they are driven or drilled wells located on ground higher than the surrounding ground to assure positive drainage from the well; b. well casings are water tight to a distance of at least 25 feet below the ground surface; c, water supply and electrical lines have a watertight seal where the lines enter the casing; d. all.pumps, electrical lines and equipment are either of the submersible type or are adequately flood - proofed; and, e. check valves are installed on main water lines at wells and all building entry locations. 7. Buried and sealea 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. 8. Public or private campgrounds, provided that: 31 a. access roads require only limited fill and do not obstruct or divert flood waters; and b. no dwellings or permanent mobile homes are allowed. 9. Structures accessory to the uses permitted in this Section such as boat docks, marinas, sheds, picnic shelters, tables and toilets, provided that: a. the structures are not intended for human habitation; b. the structures will have a low flood damage potential; c. the structures will, insofar as possible, be located on ground higher than the surrounding ground and as far from the channel as possible; d. the flood - proofing standards of Chapter VII are met; and, e. the structures will be constructed and placed so as to offer a minimal obstruction �u flood flows and are anchored to prevent flotation. 32 10. Replacement of mobile homes within an existing mobile home park or mobile home 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: a. over --the -top ties be providea at each of the four corners of the mobile home, with two additional ties per side at intermediate locations Mobile homes less than 50 feel long require one additional tie per side; b. frame ties be provided at each corner of the home with five additional ties per side at intermediate points Mobile homes less than 50 feet long require four additional ties per side; c. all components of the anchoring system be capable of carrying a force of 4,800 pounds; d. any additions to the mobile home must be similarily anchored; and, e. adequate surface drainage and access for a hauler are provided. 33 11. Substantial improvements to any structure providea that the provisions of Section 5.03 -B.3. and Section 4.03 -B.4. of these Regulations are met. 12. All other artificial obstructions, substantial improvements or non - conforming uses not specifically listed in, or prohibited by, these Regulations. G. Permits;.for Flood Control 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 flood of 100 -year frequency; and, b. the cumulative effect of the levee or floodwall combined with allowable floodway fringe encroachments does not increase the unobstructed elevation of the flood of 100 -year frequency. The Floodplain Administator 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 34 Montana Department of Natural Resources and Conservation and the Federal Insurance Administration based upon the following criteria: 1. the estimated cumulative effect of other reasonable anticipated future permissable 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 only, are constructed at least 3 feet higher that the elevation of a flood of 100 --year frequency. 2. Riprap, except that which is hand - placed, if: a. the riprap is designed to withstand a flood of 100 -year frequency; b. the . riprap does not increase the elevation of the flood of 100 -year frequency; and, c. the riprap will not increase erosion upstream, downstream, or adjacent to the riprap site. 35 Y 3. Channelization projects if they do not significantly increase the magnitude, velocity or elevation of the flood of 100 -year frequency in the proximity of the project. 4. Dams, provided that: a. they are designed and constructed in accordance with approved safety standards= and, b. they will not increase flood hazards downstream, either through operational procedures or improper hydrologic design. D. Permilp for Water Diyggr Permits for the establishment of a water diversion or change in place of diversion shall not be issued if, in the judgement of the Floodplain Administrator: 1. the proposed diversion will increase the upstream elevation of the flood of 100 -year frequency; 2. the proposed diversion is not designed and constructed .to minimize potential erosion from a flood of 100 --year frequency) and, 36 Y 3. any permanent diversion structure crossing the full width of the stream channel is not designed and constructed to safely withstand up to a flood of 100 -year frequency. E. Prohiaited_Uges The following artificial obstructions and non - conforming uses are prohibited within the floodway: 1. New construction and alterations of any structure; 2. Encroachments, including fill, new construction, substantial improvements, and other development within the adopted regulatory floodway that would result in 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. 3. The construction or permanent storage of an object subject to flotation or movement during flood level periods,; 4. Mobile homes, except in an existing. mobile home park or mobile home subdivisions 37 5. 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, 6. Storage of highly toxic, flammable or explosive materials. 5.03 Floodway Fringg A. Uses'A lowed Without Permitg All uses allowea in the floodway, according to the provisions of Section 5.02 A of these Regulations, shall also be allowea without a permit in the floodway fringe. B. Uses Requiring Permits All uses allowea in the floodway subject to the issuance of a permit, according to the provisions of Section 5.02 B and Section 5.02 C of these Regulations, shall also be allowed by permit within the floodway fringe. In addition, new construction, substantial improvements and alterations to structures, including but not limited to residential, commercial and industrial construction, and suitable fill shall be allowed by permit from the Floodplain Administrator subject to the following conditions: 38 1. Such structures or fill must not be prohibited by any other statute, regulation, ordinance or resolution; 2. Such structures or fill must be compatible with local comprehensive plans; 3. The new construction, alterations and substantial improvements of residential stKMgtures must be constructed on suitable fill such that bottom floor elevations (including basement) are two feet or more above the elevation of the flood of 100 --year frequency. The suitable fill shall be at an elevation no lower than the elevation of the flood of 100 --year frequency and shall extend for at least fifteen feet, at that elevation, beyond the structures in all directions; 4. The new construction, alteration and substantial improvement of commercial and industrial structures must be either constructed on suitable fill, as specified in Section 5.03 -B.3. of these Regulations, or be adequately flood - proofed to an elevation no lower than two feet above the elevation of the flood of 100 --year frequency. Flood-proofing shall be accomplished in accordance with Chapter VII of these Regulations and shall further include impermeable membranes or materials for floors and walls, 39 water -tight enclosures for all windows, doors, and other openings, and be certified by a registered professional engineer or architect that the flood - proofing methods are adequate to withstand the flood depths, pressures, velocities, impact and uplift forces associated with the flood of 100 --year frequency; 5. A development proposed for a 100- -year floodplain, where water surface elevations are available but no floodway is delineated, may not significantly increase flood velocities or depths or generally alter patterns of flood flow. The Floodplain Administrator may require a permit applicant to furnish additional hydraulic data before acting on a permit application for such a floodplain. The data may include, but are not limited to, any of the following: a. a hydraulic study documenting probable effect on upstream or downstream property owners caused by the proposed development; or, b. the calculated increase in the 100 -year frequency water surface profile caused by the proposed development. 40 Permits for such proposed development may be modified or denied if the additional information shows that the proposed use would cause an additional flood hazard to adjacent property or significantly increase flood heights. A significant increase in flood heights is to be one-half 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 developments that contain at least 50 lots or 5 acres (whichever is less); 6. Mobile home stands on lots are elevated on compacted fill so that the lowest floor of the mobile home will be two feet above the elevation of the 100 --year flood. a. Adequate surface drainage and access for a hauler are provided for. 7. Mobile homes proposed for use as a residential, commercial or industrial structure must meet the anchoring requirements of Section 5.02 -B.10. of these Regulations; 41 8. 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 feet above the elevation of the flood of 100 -year frequency; , and, 9. 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 flotation or collapse. C. Prohibited Uses The following artificial obstructions and non -- conforming uses are prohibited within the floodway fringe: 1. 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, 2. Storage of highly toxic, flammable, or explosive materials. Storage of petroleum products may be allowed by permit if buried in tightly seoled and contained containers or if stored on compacted fill at least two feet above the elevation of the flood of 100 -year frequency 42 CHAPTER VI GENERAL STANDARDS 6.01 Applications The minimum floodplain'development.-standards listed in this chapter apply to the 100 -year floodplains delineated -by approximate methods and identified as unnumbered A Zones on the Jefferson County Flood Insurance Rate Maps. A. Use§ Allowed Without_ Permits All uses allowea in a floodway, according to the provisions of Section 5.02 -A of these Regulations, shall also be allowed without a permit in the floodway fringe. B. Uses R auiring Permits All uses allowed in the floodway fringe subject to the issuance of a permit, according to the provisions of Section 5.03 -B, shall require permits from the Floodplain Administrator for Zone A floodplains. Also, the provisions of Section 5.03 -B.5. apply to the Zone A floodplains with no floodway delineated or water surface profile computed. Since there are no 100 -year frequency r 43 r surface profiles computed for Zone A floodplains, the following conditions also shall apply: 1. Elevation data on the 100 -year frequency flood shall be provided for subdivision proposals and other proposed developments which contain at least 50 lots or 5 acres (whichever is less) and used in applying Sections 5.03 -B.3 and 5.03 -B.4 of these Regulations; 2. Obtain, review, and reasonably utilized any 100 -year flood elevation data available from a Federal, State, or other source, until such data has been provides by the Federal Insurance Administration to enforce Section 5.03 B.3 and 5.03 B.4 of these Regulations, and; 3. Historical flood elevations may be used by the Floodplain Administrator in determining suitable fill or flood - proofing elevations to be achieved, and used in accordance with Section 5.03 -B.3. and Section 5.03 -B.4. of these Regulations; 4. If historical flood evidence is not available, then the Floodplain Administrator shall determine, from a field review at the proposed development site, an appropriate fill and /or flood-proofing elevation to be utilized in applying Sections 5.03 -B.3. and 5.03 -B.4. of these Regulations; 44 a 5. Proposed structures must be anchored to prevent flotation or collapse and must be located as far from stream channels as practicable. C. Prohibited Uses Those uses prohibited in the Floodway Fringe, in accordance with Section 5.03 -C. of these Regulations, shall also be prohibited within the Zone A floodplain boundaries. D. Flogdplain Boundiry Interpretation The Floodplain Administrator shall make interpretations where needed, as to the exact location of the Zone A floodplain boundary when there appears to be a conflict between a mapped boundary and actual field conditions. 45 CHAPTER VII FLOOD-PROOFING REQUIREMENTS 7.01 Cgrtificati n If the following flood- proofing requirements are to be utilized for 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 listed below: A. Electrical Systems 1. All incoming power service equipment, including all metering equipment, control centers, transfoarmers, distribution and lighting panels and all other stationary equipment must be located at least two feet above the elevation of the flood of 100 -year frequency; 46 2. Portable or movable electrical equipment may be placed below the elevation of the flood of 100 -year frequency, if 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 floodplain of 100 -year frequency and above the elevation of the flood of 100 --year frequency; 4. All electrical wiring systems installed at or below the elevation of the flood 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; 47 1 2. Manually operated gate valves that can be operated from a location above the elevation of the flood of 100 -year frequency also shall be provided in gas supply lines; 3. Electric heating systems must be installed in accordance with the provisions of Section 7.02 A. 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; , 2. All toilet stools, sinks, urinals and drains must be located such that the lowest point of possible water entry is at least 2 feet above the elevation of the flood of 100 -year frequency. 48