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HomeMy WebLinkAboutOrdinance 75- 953, Establishes flood hazard district; repeals Ord. 952. I I I 351 ORDINANCE NO. 953 AN ORDINANCE OF THE CITY OF BOZEMAN, MONTANA, ESTABLISHING A FLOOD HAZARD DISTRICT, DEFINING ITS BOUNDARIES, PROVIDING FOR THE ISSUANCE OF SPECIAL PERMITS, PROHIBITING SPECIFIC USES, DESIGNATING FLOOD- PROOFING REQUIREMENTS, PROVIDING FOR APPEALS AND VARIANCES, AND REPEALING ORDINANCE NO. 952 AND ALL ORDINANCES IN CONFLICT HEREWITH. BE IT ORDAINED BY THE CITY COMMISSION OF THE CITY OF BOZEMAN, MONTANA, AS FOLLOWS, 'ID WIT: Section 1 In ten t The Flood Hazard District is an area subject to periodic inundation from flood waters which may overflow from local streams and rivers. In order to avoid hazard to health, safety, and public and personal property, this section has been designed to restrict or prohibit uses which are vulnerable to flood damage or loss or which may cause increased flood heights or velocities. Sec tion 2 Special Definitions 1. "Alteration" means any change or addition to an artificial obstruction that either increases the size of the artificial obstruction or increases its potential flood hazard. Maintenance of an artificial obstruction is not an alteration. However, the repair, reconstruction, or improvement of an artificial obstruction, the cost of which equals or exceeds fifty (50) percent of the replacement cost of the artificial obstruction either (a) before the improvement is started, or (b) if the arti- ficial obstruction has been damaged and is being restored, before the damage occurred, is an altera- tion and not maintenance. 2. "Channelization project" means the excavation and construction of an artificial channel for the purpose of diverting the entire flow of a watercourse or drainway from its established course. 3. "Flood Fringe" means that portion of a designated floodplain outside the limits of a designated f100dway. 4. "Floodplain" means the area adjoining the watercourse or drainway which would be covered by the flood water of a flood of one hundred (100) year frequency. 5. "F1oodway" means the channel of a watercourse or drainway and those portions of the flood- plain adjoining the channel which are reasonably required to carry and discharge the flood water of any watercourse or drainway. 6. "Riprap" means stone, rock, concrete block, or analogous material that is placed along the banks or bed of a watercourse or drainway for the purpose of alleviating erosion. Section 3 District Boundaries and Delineations 1. The Boundaries of this district for the zoning jurisdiction outside of the city limits shall be as designated in the East Gallatin River and Upper Tributary Flood Hazard Analysis as prepared by the United States Department of Agriculture, Soil Conservation Service. The boundaries of this district within the city limits shall be as designated on the Flood Hazard Area Map as prepared by the U. S. Department of Housing and Urban Development. 2. The mapping of the Flood Hazard District does not delineate the boundary between the "FIGlod. way" and the "Flood Fringe". Until such a delineation has been officially made, the requirements of this section shall be uniform for the entire floodplain. 3. The requirements of this section are to be applied as an overlying district in addition to those contained in the basic underlying zone. Section 4 Procedure In addition to the requirements of the Zoning Code for building and land use permits, the follow- ing procedure shall be followed in the Flood Hazard District: 1. Where a special permit to allow a new use in the Flood Hazard District is required under the terms of this section, an application form may be obtained from the office of the City Building Official. 2. The application shall be filled out and attached to the building or land use permit application when submitted to the Building Official's office for approval. 3. The Building Official shall issue the special permit if, in his opinion, the requirements of this section and of the underlying district have been met. Note: for the purpose of enforcing these requirements, the Building Official may require a land survey with elevations be submitted by a land surveyor licensed by the state to practice as such. ORDINANCE No. 953 352 Section 5 Uses Not RequirinK A Special Permit A special permit is not required in the Flood Hazard District for the following uses, provided they do not require structures (other than portable structures) fill, or permanent storage of mat- erials or equipment. l. Agricultural uses; 2. Industrial-commercial uses, such as loading areas, parking areas, and emergency landing strips; 3. Private and public recreational uses, such as golf courses, driving ranges, archery ranges, picnic grounds, boat launching ramps, swimming areas, parks, wildlife management and natural areas, game farms, fish hatcheries, shooting preserves, target ranges, trap and skeet ranges, hunting and fishing areas, and hiking and horseback riding trails; 4. Forestry, including processing of forest products with portable equipment; and, 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 five hundred (500) feet from domestic supply wells; and, 7. Fences, except permanent fences crossing channels. Section 6 Uses requiring A Special Permit A special permit shall be required for the alteration, location or construction of all uses other than those uses listed in Section 5, subject to the following conditions: 1. Residential structures and customary accessory buildings shall be constructed such that the lowest finished floor elevation (including basement) are two (2) feet or more above the elevation of the flood of one hundred (100) year frequency. Footings and foundations may be built by any method permitted by the current issue of the Uniform Building Code. The fill shall be at an elevation no lower than the elevation of the flood of one hundred (100) year frequency and shall extend for at least fifteen feet at that elevation beyond the structure in all directions, and shall meet the standards set forth in Chapter 70 of the Uniform Building Code. Where existing streets, utilities, or lot dimensions make strict compliance with this provision impossible, the City Building Official may authorize through the permit a lesser amount of fill or alternative f1oodproofing measures. The City Building Official shall notify the Department of Natural Resources, State of Montana, and receive its approval prior to approving any lesser fill or alternative f10odproofing for residential structures; 2. New commercial and industrial structures shall be either constructed as specified in the preceding subparagraph or be adequately f1oodproofed up to an elevation no lower than two (2) feet above the elevation of the flood of one hundred (100) year frequency. Floodproofing shall be accom- plished in accordance with Section 8 and shall further include the following: (a) If the structure is designed to allow internal flooding of the lowest floor, use of the floor shall be limited to such uses as parking, loading areas, and storage of equipment or materials not appreciably affected by flood water. Further, the floors and walls shall be designed and constru- cted of materials resistant to flooding up to an elevation of two (2) or more feet above the elevation of the flood of one hundred (100) years frequency; and, (b) Structures whose lowest floors are used for purposes other than parking, loading, or storage or materials resistant to flooding shall be waterproofed up to an elevation no lower than two (2) feet above the elevation of the flood of one hundred (100) year frequency. Waterproof- ing shall include impermeable membranes or materials for floors and walls and watertight enclosures for all windows, doors, and other openings. These structures shall be designed to withstand the hydrostatic pressures resulting from a flood of one hundred (100) year frequency. 3. Flood control levees and floodwalls shall be designed and constructed to safely convey a flood of one hundred (100) year frequency; the cumulative effect of the levees and floodwa11s com- bined with allowable flood plain encroachments shall not increase the unobstructed elevation of a flood of one hundred (100) year frequency more than five-tenths (0.5) foot at any point, and the proposed levees and floodwal1s, except those to protect agricultural land only, shall be constructed at least three (3) feet higher than the elevation of a flood of one hundred (100) year frequency ORDINANCE NO. 953 I I I I I I where the flood level is increased more than five-tenths (0.5) foot at any point. The City Engineer may establish either a lower or higher permissable increase in the elevation of the flood of one hundred (100) year frequency for individual levee projects, based on the following criteria; (a) The estimated cumulative effect of other reasonably anticipated future permissible uses; and, (b) The type and amount of existing flood prone development in the affected a rea. 4. Riprap, except that which is hand placed, shall be placed so that: (a) The riprap will withstand a flood of one hundred (100) year frequency; (b) The rip rap does not increase the elevation of the flood of one hun- dred (100) year frequency; and, (c) The riprap will not increase erosion upstream, downstream, or across stream from the riprap site. 5. Channelization projects if they do not significantly increase the magnitude, velocity, or elevation of the flood of one hundred (100) year frequency downstream from such projects. 6. Dams shall be designed: (a) In accordance with approved safety standards; and, (b) Shall not increase flood hazards downstream, either through operational proceedures or improper hyd~ologic design. 7. Proposed structures must be anchored to prevent flotation or collapse and must be located as far from stream channels as is practicable; and, 8. Where a proposed development within such designated floodplain may significantly increase flood velocities or depths, additional hydraulic and survey information may be required of the permit applicant before a permit application is acted upon. This information may include but not be limited to any of the following: (a) Valley Cross Sections of the watercourse and adjoining floodplain; (b) Certification by a qualified professional engineer that floodproof- ing measures are reasonably adequate to protect against major flood damages; or, (c) A hydrologic study documenting probable effect on upstream or downstream property owners. Section 7 Prohibited Uses The following uses are prohibited in the Flood Hazard District: 1. Solid waste disposal and soil absorption sewage systems, except as allowed or approved under laws and standards administered by the 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 tfghtly sealed and constrained containers or if stored on com- pacted fill at least two (2) feet above the elevation of the flood of one hundred (100) year frequency. Section 8 Floodproofing Requirements. I. All electrical service materials, equipment, and installation for uses permitted with or without a special permit in the Flood Hazard District shall conform to the following conditions: (a) All incoming power service equipment, including all metering equip- ment, control centers, transformers, distribution and lighting panels, and all other and all other stationary equipment must be located at least two (2) feet above the elevation of the flood of one hundred (100) year frequency with the eKception: Portable or movable electrical equipment may be placed below the elevation of the flood of one hundred (100) year frequency, provided that the equip- ment can be disconnected by a single plug-and-socket assembly of the submersible type; 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 designated flood- plain and above the elevation of the flood of one hundred (100) year frequency; and, ORDINANCE NO. 953 353 354 All electrical wiring systems installed below the elevation of the flood of one hundred (100) year frequency shall be suitable for contin- uous submergence and may not contain fibrous components. 2. Heating systems for permitted Flood Hazard District uses shall conform to the following conditions: (a) Float operated automatic control valves, autom~tic pilots, or other alternatives shall 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; (b) Manually operated valves that can be operated from a location above the elevation of the flood of one hundred (100) year frequency shall also be provided in gas supply lines; and, (c) Electric heating systems must be installed in accordance with item one (1) of this section. 3. Plumbing systems for permitted Flood Hazard District uses shall conform to the following conditions; (a) Sewer lines, except those to buried and sealed vaults, shall have check valves installed to prevent sewage backup into permitted struc- tures; and, (b) All toilet stools, sinks, urinals, and drains shall be located such that the lowest point of possible water entry is at least two (2) feet above the elevation of the flood of one hundred (100) year frequency. Section 9 Additional Factors In addition to the other requrements of this section, the following additional factors shall be reviewed by the City Engineer before a special permit is granted or denied: 1. The danger to life and property from backwater or diverted flow caused by the obstruction; 2. The danger that the obstruction will be swept downstream to the injury of others; 3. The availability of alternative locations; 4. The construction of alteration of the obstruction in such a manner as to less the danger; 5. The permanence of the obstruction; 6. The anticipated development in the foreseeable future of the area which may be affected by the obstruction; and, 7. Such other factors as are in harmony with the purposes of these rules. Section 10 Appeals and Variance Requests Appeals and variance requests from the use requirements may be granted by the Board of Adjust- ment in accordance with the provisions of Section 31 of the Bozeman Area Zoning Code, and only if: 1. Approval is first given by the Department of Natural Resources and Conservation of the State of Montana; 2. Refusal of a permit would, because of exceptional circumstances, cause a unique or undue hardship on the applicant or community involved; 3. The proposed use is adequately flood proofed; and, 4. Reasonable alternative locations outside the designated floodplain are not available. Appeals related to the boundary delineation of the Flood Hazard District shall be made to the Department of Natural Resources and Conservation of the State of Montana; where an area originally designated sa, being included in the floodplain is oficia11y deleted or the floodplain is otherwise amended by the Department of Natural Resources and Conservation, the boundaries of the Flood Hazard District shall be automatically amended to reflect these changes. Section 11 Time Period for Approval A special permit application is considered to have been automatically granted sixty (60) days after receipt of the application, unless the Building Official notifies the applicant before the sixtieth (60th) day that the permit is denied, granted, or must receive approval from the Depart- ment of Natural Resources and Conservation of the State of Montana. ORDINANCE NO. 953 I I I I I I Section 12 EMERGENCY REPAIR AND/OR REPLACEMENT Emergency repair to and/or replacement of severly damaged public transportation facilities, public water and sewer facilities, and flood control works shall be authorized under the supervis- ion of the City Engineer if: 1. Upon notification and prior to the emergency repair and/or replacement, the City Engineer determines that an emergency condition warranting immediate action exists; and, 2. The City Engineer agrees upon the nature and type of proposed emergency repair and/or replacement; 3. Authorization to undertake emergency repair and/or replacement work may be given verbally if the City Engineer feels that a written authorization would unduly delay the emergency work. Such verbal authorization shall be followed by a written authorization stating the emergency con~ dition, the type of work agreed upon, and a notation that verbal authorization had been previously given. Sec tion 13 Warning and Disclaimer of Liability The degree of flood protection required by this ordinance is considered reasonable for regulat- ory purposes and is based on needs and conditions. Floods larger than anticipated by this ordinance may occur on rare occasion or a flood may be increased by man-made or natural causes, such as ice jams and bridge openings restricted by debris. Neither this section nor this ordinance implies that areas outside the flood hazard district boundaries or land uses within the district will be free from flooding or flood damage. And, neither this section nor this ordinance shall create liability on the part of the City of Bozeman, or any officer or employee thereof for any flood damages that result from reliance upon this ordinance or any administrative decision lawfully made thereunder. Section 14 Repeal Ordinance No. 952 of the City of Bozeman, and all ordinances and parts of ordinances in con- flic~ herewith are hereby expressly repealed. PASSED, ADOPTED, AND APPROVED by the City Commission of the City of Bozeman this 16th day of April, 1975. EDMUND P. SEDIVY, SR., Mayor ATTEST: ~~~~~~ Clerk of the City Comm1ssion State of Montana ) County of Gallatin : City of Bozeman ) I, Erna V. Harding, Clerk of the Commission of the City of Bozeman, do hereby certify, that the foregoing Ordinance No. 953 was published by Title and Number in the Bozeman Daily Chronicle, a newspaper of general circulation printed and published in Bozeman in the issue of the 20th day of April 1975, and due proof of such publication is on file in my office. IN WITNESS WHEREOF I hereunto set my hand and affiK the corporate seal of my office this 1st day of May 1975. p <"' ,/ c:::,-: /" ~c /~... /' " C:2'-zc~k~ ERNA V. HARDING, Clerk of ~he City Commission ORDINANCE NO. 953 355