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HomeMy WebLinkAboutOrdinance 87- 1237 Repeals and replaces Ord. 1097, floodplain regulations 2Y9 ORDINANCE NO. 1237 AN ORDINANCE OF THE BOZEMAN CITY COMMISSION REPEALING THE FLOOD HAZARD DISTRICT ESTABLISHED BY ORDINANCE NO. 1097 AND AS CODIFIED IN CHAPTER 18.44 OF THE BOZEMAN MUNICIPAL CODE AND ADOPTING THE BOZEMAN AREA FLOOD PLAIN REGULATIONS IN ITS STEAD. INTENT I This Ordinance is passed in order to comply with the Montana Floodplain and Floodway Management Act (Title 76, Chapter 5-MCA) and to ensure compliance with the requirements for the continued participation by the City of Bozeman, Montana in the National Flood Insurance Program. Land-use regulations which are hereby adopted are to be applied to all identified 100-year floodplains within local zoning jurisdiction. REPEAL Ordinance No. 1097 is hereby repealed. BOZEMAN AREA FLOODPLAIN REGULATIONS TITLE AND PURPOSE 1.01 Title - These Regulations shall be known and cited as The Bozeman Area Floodplain Regulations. These Regulations are in accordance with exercising the authority of the laws of the State of Montana. 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: A. To guide development of the 100-year floodplain area within the Bozeman Zoning Jurisdiction area 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; I 2. Participating in coordinated efforts of federal, state, and local management activities for 100-year floodplains; and 3. Ensuring the regulations and minimum standards adopted, insofar as possible, balance the greatest public good with the least private injury. B. Specifically it is the purpose of these Regulations to: 1. Restrict or prohibit uses which are dangerous to health, safety, and property in times of flood, or cause increased flood heights and velocities; 2. Require that uses vulnerable to floods, including public facilities, be provided with flood protection at the time of initial construction; 3. Utilize information which identifies lands unsuitable for certain development purposes because of flood hazards; 4. Minimize the need for rescue and relief efforts associated with flooding undertaken at the expense of the general publ ic; 5. Ensure that potential buyers are notified that property is within a 100-year floodplain and subject to the provisions of these Regulations; and 6. Ensure that those who occupy 100-year floodplains assume responsibility for their actions. DEFINITIONS 2.01 Definitions 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 I Regulations the most reasonable application. Alteration--Any change or addition to a structure that increases its external dimensions. Appeal--A request for a review of the Floodplain Administrator's interpretation of any provisions of these Regulations or 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 flooding in any given year, i. e. the 100-year floodplain. Artificial Obstruction - Development--Any obstruction which is not natural and includes any dam, diversion, wall, riprap, embankment, levee, dike, pile, abutment, projection, ORDINANCE NO. 1237 250 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 I any given year. A base flood is the same as a 100-year flood. Channelization Project--The excavation and/or construction of an artificial channel for the purpose of diverting the entire flow of a stream from its established course. Establish--To construct, place, insert, or excavate. Flood or Flooding--A general and temporary condition of partial or complete inundation or normally dry lands from the overflow of a stream, or the unusual and rapid accumulation or runoff of surface waters from any source. Floodplain-- The areas generally adjoining a stream which would be covered by floodwater. It consists of a floodway and flood way fringe. Floodway-- The channel of a stream and the adjacent overbank areas that must be reserved in order to discharge a base flood without cumulatively increasing the water surface elevation more than one-half (1/2) foot. Floodway Fringe-- That portion of the floodplain outside the limits of the floodway. Flood Insurance Rate Map--The map on which the Federal Emergency Management Agency has delineated both the 100-year floodplains and the risk premium zones. Flood Insurance Study--The report in which the Federal Emergency Management Agency has provided flood profiles, as well as the Flood Boundary - Floodway Map and the water surface profiles. Levee--A man-made structure, usually earthen embankment, designed and constructed in accordance with sound engineering practices to contain, control, or divert the flow of water so as to provide protection from temporary flooding. I Levee System--A flood protection system which consists of a levee, or levees, and associated structures, 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 permanent chassis, and designed to be used with or without a permanent foundation when connected to the required utilities. For floodplain management purposes it also includes park trai lers, travel trai lers, and other simi lar vehicles placed on a site for greater than 180 consecutive days. 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 the start of construction, substantial improvement, or alteration commences on or after the effective date of these Regulations. Non-Conforming Use--A land use not in accordance with these Regulations. Official Floodplain Maps-- The Flood I nsurance Rate Maps and Flood Boundary-Floodway Maps provided by the Federal Emergency Management Agency for Bozeman, Montana dated March 15,1982. Permit Issuing Authority--Bozeman City Commission. I Riprap--Stone, rocks, concrete blocks, or analogous material that is placed along the banks or bed of a stream for the purpose of alleviating erosion. Start of Construction-- The first placement of permanent construction of a structure on a site, such as pouring of slabs or footings or any work beyond the state' of excavation. Permanent construction of residential structures does not include land preparation, such as clearing, grading, and filling, nor does it include the installation of streets, and/or walkways; nor does it include the excavation for a basement, footings, piers, or foundation or the erection of temporary forms; nor does it include the installation on the ORDINANCE NG. 1237 251 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 manufactured 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 pi ling or foundation. For manufactured homes or within a manufactured home park or subdivision, start of construction is the completion date of construction of facilities for servicing the I manufactured home site. At a minimum this includes the construction of streets, either final site grading or the pouring of concrete pads, and the installation of utilities. For manufactured homes being replaced in an existing park or subdivision, start of construction means placement of the home on the foundation. Structure--A walled and roofed building, manufactured home, or a gas or liquid storage tank, that is principally above ground. Substantial Improvement--Any repair, reconstruction, or improvement of a structure, the cost of which equals or exceeds fifty percent (50%) of the market value of the structure either: ( 1 ) before the improvement or repair is started, or (2) if the structure has been damaged, and is being restored, before the damage occurred. For the purposes of this definition, substantial improvement is considered to occur when the first construction to any wall, ceiling, floor, or other structural part of the building commences. The term does not include: ( 1 ) any project for improvement of a structure to comply with existing state or local health, sanitary, or safety code specifications which are solely necessary to assure safe living conditions, or (2) any alteration of a structure listed on the National Register of Historic Places or State I nventory of Historic Places. Suitable Fill--Fill material which is stable, compacted, well graded, pervious, generally I unaffected by water and frost, devoid of trash or simi lar foreign matter, tree stumps, or other organic material; and is fitting for the purpose of supporting the intended use and/or permanent structure. Variance--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. Violation-- The fai lure of a structure or other development to be fully compl iant with these regulations. A structure or other development without elevation certificate, certification by a licensed engineer or architect, 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 1 DO-year flood is the same as a base flood. GENERAL PROVISIONS 3.01 Jurisdictional Area These Regulations shall apply to all lands within the zoning jurisdiction of the City of Bozeman, State of Montana, shown on the Official Floodplain Maps as being located within a 100-year floodplain district. 3.02 Floodplain District Establishment The floodplain districts established are defined by the 100-year floodplains as a delineated in the Flood I nsurance Study. The basis for the Flood I nsurance Study is a scientific and engineering report entitled, liThe Flood Insurance Study for Bozeman, Montana", dated I September 15, 1981, with accompanying Flood Insurance Rate Maps and Flood Boundary - Floodway Maps. The Official Floodplain Maps, together with the Flood Insurance Study are on file in the office of the Floodplain Administrator. 3.03 Floodplain Administrator The Bozeman Floodplain Administrator has been designated to be the City Engineer. 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 dista'nces on the official floodplain maps. For unnumbered A Zones and AO Zone floodplains, ORDINANCE NO. 1237 252 where there is a confl ict between a mapped floodplain boundary and actual field conditions, the Floodplain Administrator may determine that the area is not to be included within the 100- year floodplain. The property owner or developer then does not have to satisfy the provisions of these Regulations. 3.05 Compliance No structure or land use shall be located, extended, converted, altered or substantially improved without full compliance with the provisions of these Regulations and other applicable I 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 I nsurance Program regulations. 3.06 Abrogation and Greater Responsibility It is not intended by these Regulations to repeal, abrogate, or impair any existing easements, convenants, deed restrictions, or under lying zon ing. However, where these Regulations impose greater restrictions, the provisions of these Regulations shall prevai I. 3.07 Regulation Interpretation The interpretation and application of the provisions of these Regulations shall be considered minimum requirements and liberally construed in favor of the governing body and not deemed a limitation or repeal of any other powers granted by State statute. 3.08 Warning and Disclaimer of Liability These Regulations do not imply that areas outside the delineated floodplain boundaries or permitted land uses wi II always be totally free from flooding or flood damages. These regulations shall not create a liability or cause of action against Bozeman, Montana, or any officer or employee thereof for flood damages that may result from rei iance upon these Regulations. 3.09 Severability I f 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. 3.10 Disclosure Provision I All owners of property in an identified 100-year floodplain as indicated on the Official Floodplain Maps must notify potental buyers or their agents that such property is subject to the provisions of these Regulations. ADMINISTRATION 4.01 Administration A. As provided in Section 3.03 of these Regulations, the Floodplain Administrator has been designated by the City Commission, and has the responsibility of such position as outlined in these Regulations. B. The Floodplain Administrator is hereby appointed with the authority to review floodplain development permit applications, proposed uses, and construction to determine compliance with these Regulations. The Floodplain Administrator is required to assure all necessary permits have been received from those governmental agencies from which approval is required by federal and state law and local codes, including Section 404 of the Federal Water Pollution Control Act of 1972, 33 U. S. C. 1334. 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 development 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 I caused by encroachments; b. the danger that materials may be swept onto other lands or downstream to the injury of others; c. the proposed water supply and sanitation systems and the abi lity 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; ORDINANCE NO. 1237 . ? 5" _ 0 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 I anticipated development in the foreseeable future; i. the relationship of the proposed use to the comprehensive plan and floodplain management program for the area; j . the safety of access to property in times of flooding for ordinary and emergency services; and k. such other factors as are in harmony with the purposes of these Regulations, the Montana Floodplain and Floodway Management Act, and the National Flood Insurance Program. C. A floodplain development permit application is considered to have been automatically granted sixty (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 fi les and records as may be necessary to document nonconforming uses, flood elevation, floodproofing and elevation certification, fee receipts, the issuance of permits, agendas, minutes, records of publ ic meetings, and any other matters related to floodplain management in the Bozeman Zoning Jurisdictional Area. Such files and records shall be open for public inspection. In 'matters of litigation the City Attorney may restrict access to specific records. I F. Copies of all 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 Emergency Management Agency 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. Permit Applications 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 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, fi II, storage or materials site, flood-proofing measures, mean sea level elevation of first floor of proposed structures, location of the channel and I imits of 100-year floodplain boundary. 2. A plan view of the proposed development indicating external dimensions of structures, street or road finished grade elevations, well locations, individual I 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 location of utilities. 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: ORDINANCE NO. 1237 25Li- 1. Certification by a registered professional engineer or licensed land surveyor of the actual mean sea level elevation of the lowest floor (including basement) of all new, altered, or substantially improved structures. 2. I f flood-proofing techniques were used for structures, the mean sea level elevation to which the flood proofing was accomplished must be certified in the same manner. 4.03 Emergency Waiver I A. Emergency repair and/or replacement of severely damaged public transportation facilities, public water and sewer facilities, and flood control works may be authorized. Floodplain development permit requirements may be waived if: 1. Upon notification and prior to the emergency repair and/or replacement, the Floodplain Administrator determines that an emergency condition exists warranting immediate action; and 2. The Floodplain Administrator agrees upon the nature and type of proposed emergency repair and/or replacement. B. Authorization to undertake emergency repair and/or replacement work may be given verbally if the Floodplain Administrator feels that written authorization would unduly delay the emergency works. Such verbal authorization must be followed by a written authorization stating the emergency condition, the type of emergency work agreed upon, and a notation that a verbal authorization had been previously given. 4.04 Review-Va riances-Appea I s A. There is hereby created a local Floodplain Management Board of Adjustment, the membership, administration, and rules of procedure of which are identical to a board of adjustment. B. The Board of Adjustment may, by variance, grant a permit that is not in compliance with the minimum standards contained in these Regulations according to the following procedures: 1. Variances shall not be issued for areas within a floodway if any increase in I flood elevations or velocities would result; 2. Variances shall on Iy be issued upon: a. a showing of good and sufficient cause; b. a determination that refusa I 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 heights, present additiona I 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 Bozeman City Commission, prior to formally approving any permit application which is in variance to these Regulations. 3. Variances shall be issued in writing from the Permit I ssuing Authority and I shall notify the applicant that: a. a specific variance is granted, and certain conditions may be attached; b. the issuance of a variance to construct a structure below the 100-year floodplain elevation wi II result in increased premium rates; and c. such construction below the 100-year flood elevation increases risks to life and property. The Floodplain Administrator shall maintain records of the variance notification and actions, including justification for their ORD I NANCE NO. 1237 . 25b issuance, and forward copies of all variance actions to the Montana Department of Natural Resources and Conservation and the Federal Emergency Management Agency. C. Appeal of any decision of the Permit Issuing Authority, its officers, or agencies may be taken by an aggrieved person or persons, jointly or separately, to a court of record. I 4.05 Fees - A processing fee of FIFTY DOLLARS ($50.00) 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; the City Attorney; and the Montana Department of Natural Resources and Conservation. 4.07 Compl iance 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, 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 fai lure to comply with any of the requirements, including permit approval prior to development within the floodplain boundaries and conditions and safeguards established in connection with variances, shall constitute a misdemeanor. Any person who violates these Regulations or fails to comply with any of its requirements shall, upon conviction, be fined not more than ONE HUNDRED DOLLARS ($100) or imprisoned in jai I for not more than ten (10) days or both. Each day1s continuance of a I violation shall be deemed a separate and distinct offense. 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 Boundary-Floodway Maps, and also correspond to the numbered A or AE zones depicted on the Flood I nsurance Rate Maps. 5.02 Floodway A. Uses Allowed Without Permits. The following open space uses shall be allowed without a permit within the floodway, provided that such uses conform to the provisions of Chapter VII of these Regulations, are not prohibited by any other ordinance, resolution, or statute and do not requi re fill, excavation, permanent storage of materia Is, 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 faci lities; 3. Private and public recreational uses such as golf courses, driving ranges, archery ranges, picnic grounds, boat-launching ramps, parks, wi Id/ife 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; I 4. Forestry, including processing of forest products with portable equipment; 5. Residential uses such as lawns, gardens, parking .areas, and play areas; 6. I rrigation and livestock supply wells, provided that they are located at least Five Hundred (500) feet from domestic water supply wells; and B. Uses 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: ORDINANCE NO. 1237 255 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 stockpiled outside the floodway. I 2. Rai Iroad, highway, and street stream crossings provided the crossings are designed to offer minimal obstruction to flood flow and do not increase elevation of the 100-year flood more than one-half foot. 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. 4. Buried or suspended utility transmission lines, provided that: a. suspended utility transmission lines are designed so the lowest point of the suspended line is at least six (6) feet higher than the elevation of the 100-year flood; 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 for a 100-year flood. 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 Floodplain Administrator. 5. Storage of materials and equipment, provided that: I 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 movable within the limited time available after flood warning. Storage of flammable, toxic, 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 form the well; b. well casings are water tight to a distance of at least twenty-five (25) feet below the ground su rface; c. water supply and electrical lines have a watertight seal where the lines enter the casing; d. all pumps, electrical lines, and equipment are either submersible or adequately flood~proofed; and e. check valves are installed on main water lines at wells and at all bui Iding 'entry locations. 7. Buried and sealed vaults for sewage disposal in recreational areas, provided they meet applicable laws and standards administered by the Montana Department of Health and Environmental Sciences. 8. Public or private campgrounds, provided that: a. access roads require only limited fill and do not obstruct or divert I flood waters; and b. manufactured homes, including travel trai lers and park trai lers, are not in place more than one-hundred eighty (180) consecutive days. 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 wi II have a low flood damage potential; ORDINANCE NO. 1237 251 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 minimal obstruction to flood flows and a re anchored to prevent flotation. 10. Fences, except permanent fences crossing channels. I 11. Substantial improvements to any structure provided that the provisions of Section 5.03-B.3 and Section 5.03-B.4 of these Regulations are met. 12. All other artificial obstructions, substantial improvements, or non-conforming uses not specifically I isted or prohibited by these Regulations. C. Permits for Flood Control Works. Flood control works shall e allowed within floodways subject to the issuance of a permit b;y 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-year flood; and b. the cumulative effect of the levee or floodwall combined with allowable flood way fringe encroachments does not increase the unobstructed elevation of the 1 OO-yea r flood. The Floodplain Administrator may establish either a lower or higher permissible increase in the elevation of the 100-year flood for individual levee projects. Any change must be in concurrence with the Montana Department of Natural Resources and Conservation and the Federal Emergency Management Agency based upon the following criteria: 1 ) the estimated cumulative effect of any anticipated future reasonable permissible uses; and 2) the type and amount of existing flood-prone development in the I affected area. c. the proposed levee or floodwall, except those to protect agricultural land, are constructed at least three (3) feet higher than the elevation a 100-year flood. 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 elevation of the 100-year flood; and c. the riprap will not increase erosion upstream, downstream, or adjacent to the riprap site. 3. Channelization projects if they do not significantly increase the magnitude, velocity, or elevation of the 100-year flood 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. 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 elevation of the 100-year flood to the detriment of neighboring property; I 2. the proposed diversion is not designed and constructed to minimize potential erosion from a 100-year flood; and 3. any permanent diversion structure crossing the full width of the stream channel is not designed and constructed to safely withstand up to a 100-year flood. E. Prohibited Uses. The following artificial obstructions and non-conforming uses are prohibited within the floodway: 1. New construction, substantial improvements, and alterations of any residential, commercial, or industrial structure; ORDINANCE NO. 1237 258 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 flotation or movement during flood level periods; I 4. New Construction, replacement, substantial improvements, and alterations of manufactured homes. 5. Solid waste disposal, sewage treatment, and sewage disposal systems, except as al lowed 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 Fringe A. Uses Allowed Without Permits. All uses allowed in the floodway, according to the provisions of Section 5. 02A of these Regulations, shall also be allowed without a permit in the floodway fringe. B. Uses Requiring Permits. All uses allowed in the floodway subject to the issuance of a permit, according to the provisions of Section 5.028 and Section 5. 02C of these Regulations, shall also be allowed by permit within the floodway fringe. In addition, new construction, substantial improvements, and alterations to structur-es are allowed by permit. This includes but is not limited to residential, commercial, and industrial construction, and suitable fill to be allowed by permit from the Floodplain Administrator and 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 I residential structures including manufactured homes must be constructed on suitable fill such that the lowest floor elevation (including basement) is two feet or more above the elevation of the 100-year flood. The suitable fill shall be at an elevation no lower than the elevation of the 100-year flood and shall extend for at least fifteen feet, at that elevation, beyond the structure(s) in all directions; 4. The new construction, alteration, and substantial improvement of commercial and industrial structures can be constructed on suitable fill as specified in Section 5.03-B.3 of these Regulations. I f not constructed on fill, commercial and industrial structures must be adequately flood-proofed to an elevation no lower than two (2) feet above the elevation of the 100-year flood. Flood-proofing must be certified by a registered professional engineer or architect that the flood-proofing methods are adequate to withstand the flood depths, hydrodynamic and hydrostatic pressures, velocities, impact, buoyancy, and uplift forces associated with the 100-year flood; a. if the structure is designed to allow internal flooding of the lower floor, use of the lowest floor shall be limited to parking, loading areas, and storage of equipment or materials not appreciably affected by flood waters. The floors and walls shall be designed and constructed of materials resistant to flooding to an elevation no lower than two feet above the 100-year flood elevation. Walls shall be designed to equalize hydrostatic forces by allowing for entry and exit of floodwaters. Openings may be I equipped with screens, louvres, valves, other coverings, or devices which permit the automatic entry and exit of floodwaters. b. structures whose lowest floors are used for a purpose other than parking, loading, or storage of materials resistant to flooding shall be waterproofed to an elevation no lower than two (2) feet above the 100-year flood elevation. Waterproofing shall include impermeable membranes or materials for floors and walls and watertight enclosures for all windows, ORDI NANCE NO. 1237 2 S C' , ,-::I doors, and other openings. These structures shall be designed to withstand the hydrostatic, hydrodynamic, and buoyancy effects of a 100-year flood. c. flood-proofing shall also be accomplished in accordance with Chapter VII of these Regulations. 5. Manufactured homes must be elevated on suitable compacted fill so that the I lowest floor of the manufactured home will be two (2) feet above the 100-year flood elevation. This includes new construction, substantial improvement, alteration, or replacement of manufactured homes within an existing manufactured home park or subdivision and manufactured homes on individual sites. The manufactured home must be anchored according to specifications prepared by a professional engineer to resist flotation, collapse, or lateral movement. Methods of anchoring may include, but are not limited to, use of over-the-top or frame ties to ground anchors; 6. Manufactured homes proposed for use as a commercial or industrial structure must be anchored and elevated, rather than flood-proofed; 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 (2) feet above the elevation of the 100-year flood; 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 flotation or collapse; C. Prohibited Uses: The following artificial obstructions and nonconforming uses are prohibited within the floodway fringe: 1. Solid waste disposal, sewage treatment, and sewage disposal systems, except as allowed or approved under the laws and standards administered by the I Montana Department of Health and Environmental Sciences; and 2. Storage of high Iy toxic, flammable, or explosive materials. Storage of petroleum products may be allowed by permit if buried in tightly sealed impermeable containers or if storaged on compacted fill at least two feet above the elevation of the 100-year flood and anchored to prevent downstream movement. 5.04 Floodplain Areas with Flood Elevations and No Delineated Floodway A. A development proposed for a 100-year floodplain, where water surface elevations are available but no floodway is delineated, may not significantly increase food velocities or depths or generally alter patters of flood flow. The provisions of Section 5.03, Floodway Fringe, shall apply to these areas. The Floodplain Administrator may require a permit applicant to furnish additional hydraulic data before acting on a permit application for such a floodplain. The data may include, but are not I imited to, any of the following: 1. a hydraulic study documenting probable effect on upstream or downstream property owners caused by the proposed development; or 2. the calculated increase in the 100-year flood frequency water surface profi Ie caused by the proposed development. B. Permits for such proposed development may be modified or denied if the additional information shows that the proposed use would cause an additional flood hazard to adjacent property or significantly increase flood heights. A significant increase in flood heights is one-half foot unless existing or anticipated development in the area dictates a I lesser amount of allowable increase. 5.05 Shallow Flooding (AO Zones) 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 Zone floodplains. The depth of the 100-year flood is indicated as the depth number on the Flood I nsurance Rate Maps. The 100-year flood depth shall be referenced to the highest adjacent grade or stream flow line in determining fill or flood-proofing heights which are to be utilized in applying the provisions of Section 5.03-B.3 and Section 5.03-B.4 of these Regulations. In the absence of depth or elevation information a two-foot (2') flood depth should be used. ORDINANCE NO. 1237 2bU 1. Floodplain Boundary Interpretation. The Floodplain Administrator shall make interpretations where needed as to the exact location of an AO Zone floodplain boundary when there is a conflict between a mapped boundary and actual field conditions. GENERAL STANDARDS 6.01 Applications The minimum floodplain development standards listed in this chapter apply to the 100-year I floodplains delineated by approximate methods and identified as unnumbered A Zones on the Flood Insurance Rate Maps. A. Uses Allowed Without Permits. All uses allowed in a floodway, according to the provisions of Section 5. 02-A of these Regulations, shall a Iso be allowed without a permit in the floodway fringe. B. Uses Requiring 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 apply to the Zone A floodplains with no floodway delineated or water surface profi Ie computed. Since there are no 100-year frequency water surface profiles computed for Zone A floodplains, the following conditions also apply: 1. Elevation data on the 100-year flood shall be provided by the applicant for subdivision proposals, manufactured home parks, 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 utilize any 100-year flood elevation and floodway data avai lable from federal, state, or other sources, until such data have been provided by the Federal Emergency Management Agency 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 utilized in applying I 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 determine, from a field review at the proposed development site, an appropriate fill or flood-proofing elevation to be utilized in applying Sections 5.03-B.3 and 5.03-B.4 of these Regulations; and 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. Floodplain Boundary Interpretation. The Floodplain Administrator shall make interpretations where needed as to the exact location of the Zone A floodplain boundary when there is a conflict between a mapped boundary and aetual field conditions. FLOOD-PROOFI NG REQU I REMENTS 7.01 Ce rti ficat ion 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 belowhand the flood-proofing standards listed in Section 5. 03-B. 4 of these Regulations for commercial and I industrial structures. A. Electrical Systems 1. All incoming power service equipment, including all metering equipment, control centers, transformers, distribution and lighting panels, and all other stationary equipment must be located at least two feet above the elevation of the 100-year flood; 2. Portable or movable electrical equipment may be placed below the elevation of the 100-year flood, if the equipment can be disconnected by a single submersi ble plug-and-socket assembly; ORDINANCE NO. 1237 . . 2Gl 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 elevation of the 100-year flood; and 4. All electrical wiring systems installed at or below the elevation of the 100-year flood shall be suitable for continuous submergence and may not contain fibrous components. I B. Heating Systems 1. Float operated automatic control valves must be installed in gas furnace supply lines so that the fuel supply is automatically shut off when flood waters reach the floor level where the furnace is located; 2. Manually operated gate valves must be installed in gas supply lines. The gate valves must be operable from an accessible 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. 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 so the lowest point of possible water entry is at least two- feet above the elevation of the 1 OO-yea r flood. ORDI NANCE REPEALED 8.01 Ordinance Repealed All other ordinances and parts of ordinances in confl ict with these provisions are hereby repealed. SAVINGS PROVISION 9.01 Savings Provision I This ordinance does not affect rights and duties that matured, penalties that were incurred or proceedings that were begun before the effective date of this ordinance. SEVERAB I L1TY 10.01 Severability I f any provision of this ordinance is declared unconstitutional, or the applicability thereof to any person or circumstances is held invalid, the constitutionality of the remainder of the ordinance and applicability thereof to other persons and circumstances shall not be affected thereby. PROVISIONALLY PASSED AND ADOPTED by the City Commission of the City of Bozeman, Montana, this 6th day of July 1987. JUDITH A. MATHRE Mayor ATTEST: ROBIN L. SULLIVAN Clerk of the Commission I FINALLY PASSED AND ADOPTED by the City Commission of the City of Bozeman, Montana, this 20th day of July 1987, and effective thirty (30) days after said date. JUDITH A. MATHRE Mayor ATTEST: ROBIN L. SULLIVAN Clerk of the Commission ORDINANCE NO. 1237 262 State of Montana ) County of Gallatin : ss City of Bozeman ) I, Robin L. Sullivan, Clerk of the City Commission of the City of Bozeman, do hereby certify that the foregoing Ordinance No. 1237 was published by title number in the Bozeman Daily Chronicle, a newspaper of general circulation printed and published in said City, in the issue dated the 23rd day of July, 1987, and said proof of such publication is on file in my office. IN WITNESS WHEREOF, I hereunto set my hand and affix the corporate seal of my I office. ROBIN L. SULLIVAN Clerk of the Commission I I ORDINANCE NO. 1237 ~