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HomeMy WebLinkAboutOrdinance-1978-0255INTRODUCED BY COUNCILPERSON CAVARRA ORDINANCE NO. 255 Series of 1978 TITLE: AN ORDINANCE AMENDING APPENDIX B, FLOOD PLAIN ZONING ORDINANCE, OF THE CODE OF LAWS OF THE CITY OF WHEAT RIDGE, COLORADO, 1976 EDITION AS AMENDED, AS FOLLOWS: BE IT ORDAINED BY THE CITY COUNCIL OF THE CITY OF WHEAT RIDGE, COLORADO THAT: Appendix B, Flood Plain Zoning Ordinance, of the Code of Laws of the City of Wheat Ridge is amended as follows: APPENDIX B. FLOOD PLAIN ZONING ORDINANCE. As to planning commission, see Sections 2-15 to 1-27 of this Code. As to board of adjustment, see Sections 2-18 to 2-24. Sec. 1.0 Sec. 2.0 Sec. 3.0 Sec. 4.0 Sec. 5.0 Sec. 6.0 Sec. 7.0 Sec. 8.0 Sec. 9.0 Sec. 10.0 Sec. 11.0 Sec. 12.0 Purposes General provisions. Nonconforming uses. Flood regulatory district. Exemptions. Administration. Certificate of compliance. Enforcement and penalties. Amendments. Definitions. Severability. Effective date. Sec. 1.0. Purposes. To promote the public health, safety and general welfare, to minimize flood losses in areas subject to flood hazards, and to promote wise use of the "flood plain," this Flood Plain Zoning Ordinance has been esta- blished with the following purposes intended: 1.1 To reduce the hazard of floods to life and property through: A. Prohibiting certain uses which are dangerous to life or property in time of flood. B. Restricting uses which would be hazardous to the public health in time of flood. C. Restricting uses which are particularly susceptible to flood damage, so as to alleviate hardship and reduce demands for public expenditures for relief and protection. ORD. NO. 255 Series of 1978 D. Requiring permitted flood plain uses, including public facilities which serve such uses, to be protected against floods by providing "flood proofing" and general flood protection at the time of initial construction. 1.2 To protect flood plain occupants from a flood which is or may be caused by their own, or other, land use and which is or may be undertaken without full realization of the danger, through: A. Regulating the manner in which structures designed for human occupancy may be constructed so as to prevent danger to human life within such structures. B. Regulating the method of construction of water supply and sanitation systems so as to prevent disease, contamination and unsanitary conditions. C. Delineating and describing areas that could be inundated by floods so as to protect individuals from purchasing flood plain lands for pur- poses which are not in fact suitable. 1.3 To protect the public from the burden of extraordinary financial expenditures for flood control and relief. A. Regulating all uses within the flood plain district so as to pro- duce a method of construction and a pattern of development which will minimize the probability of damage to property and loss of life or injury to the inhabitants of the flood hazard areas. 1.4 To protect the "storage capacity of flood plains" and to assure retention of sufficient "floodway" area to convey flood flows which can reasonably be expected to occur by: A. Regulating filling, dumping, dredging and alteration of channels by deepening, widening or relocating. B. Prohibiting unnecessary encroachments. C. Encouraging uses such as agriculture, recreation and parking. 1.5 To protect the hydraulic characteristics of the small watercourses, including the gulches, sloughs and artificial water channels used for conveying flood waters, which make up a portion of the urban major drainage system. A. Regulating filling, dumping and channelization so as to maintain natural storage capacity and slow flow characteristics. B. Prohibiting encroachment into the small watercourses to maintain their water carrying capacity. C. Encouraging uses such as greenbelt, open space, recreation and riding trails. Sec. 2.0. General provisions. 2.1 Jurisdiction. The jurisdiction of the ordinance includes all lands, adjacent to any watercourse within the City of Wheat Ridge, Colorado, that would be inundated by the "100-year flood" for that watercourse as defined in the Definitions, Section 10.23 of this ordinance. 2.2 Interpretation. In their interpretation and application, the pro- visions of this ordinance 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 Colorado Statutes. - 2 - ORD. NO. 255 Series of 1978 2.3 Warning and disclaimer of liability. The degree of flood protection intended to be provided by this ordinance is considered reasonable for regulatory purposes and is based on engineering and scientific methods of study. Larger floods may occur on occasions or the flood height may be in- creased by man-made or natural causes, such as ice jams and bridge openings restricted by debris. This ordinance does not imply that areas outside flood plain zoning district boundaries or land uses permitted within such districts will always be totally free from flooding or flood damages. Nor shall this ordinance create a liability on the part of or a cause of action against the City of Wheat Ridge or any officer or employee thereof for any flood damages that may result from reliance on this ordinance. 2.4 Adoption of official maps. The location and boundaries of Clear Creek and Lena Gulch Flood Areas established by this ordinance are shown on the "Flood Plain Zoning Map of the City of Wheat Ridge" and on the "Flood Insurance Rate P1ap (FIRM) I-01", revised July 22, 1977, by the Department of Housing and Urban Development, Federal Insurance Administration for the City of Wheat Ridge, Colorado, which are hereby incorporated into this ordinance. The said maps, together with all applicable supporting technical data on which the maps are based and together with all amendments thereto, shall be as much a part of this ordinance as if fully set forth and described therein. Each change in said maps shall be subject to the Amendment Procedure as described in Section 9.0. In case of conflict between the two maps, the more restrictive map shall apply. Sec. 3.0. Nonconforming uses. 3.1 The existing lawful use of a structure or premises which is not in conformity with the provisions of this ordinance may be continued subject to the following conditions: A. No such use shall be expanded or enlarged except in conformity with the provisions of this ordinance. B. No structural alteration, addition or repair to any nonconforming structure over the life of the structure shall exceed fifty (50) percent of its assessed value at the time of its becoming a nonconforming use un- less permanently changed to a conforming use. C. If such use is discontinued for twelve (12) consecutive months, any future use of the building and premises shall conform to this ordinance. D. Uses or adjuncts thereof which are nuisances shall not be permitted to continue as nonconforming uses. E. Any alteration, addition, or repair to any nonconforming structure permitted pursuant to Section 3.1B of this ordinance shall be protected by flood proofing measures pursuant to Section 6.4E(1), Flood Proofing of this ordinance. Sec. 4.0. Area of special flood hazard. 4.1 Application. The provisions for this district apply to all flood plains of watercourses in the.City of Wheat Ridge, Colorado, for which 100- year flood data and corresponding elevations or profiles are available, and which have been approved by the State Water Conservation Board. 4.2 Description of district. The area of special flood hazard includes the area delineated on the maps and profiles for the 100-year flood plain limits for the Clear Creek and Lena Gulch watercourses in the City of Wheat Ridge, Colorado, as delineated in the revised flood plain map based upon the resurvey by Wright-McLaughlin Engineers of May, 1975, approved by the Colorado Water Conservation Board by resolution of July 9, 1975, and adopted by the city council the same date as this original ordinance and shall - 3 - ORD. NO. 255 Series of 1978 include the amended flood plain designation map on sheet 8 of 21 between station 92 and station 122. A copy of which map is included in and made a part of this ordinance, and a copy of which is on file and available in the clerk and recorder's office in Jefferson County, Colorado, with copies in the Department of Community Development, City of Wheat Ridge. 4.3 Special provisions. The following regulations shall apply to all uses within the area of special flood hazard, notwithstanding that such uses may be specifically permitted under the terms of this ordinance. A. The flood protection elevation or height shall correspond to a point one foot above the elevation or "flood profile" shown on or attached to the flood map for a particular area. B. No "structure (temporary or permanent)"; fill, including fill for roads and levees; deposit; obstruction; storage of materials; or other flood plain uses which acting alone or in combination with existing or future flood plain uses shall be permitted that to a substantial degree adversely affects the efficiency or the capacity of the floodway or in- creases flood heights or adversely affects the "storage capacity of the flood plains" based on the assumption that there will be "equal degree of encroachment" extending for a significant "reach" on both sides of the stream. C. No flood plain uses shall to a substantial degree adversely affect the efficiency of or unduly restrict the capacity of the channels or floodways of any tributaries to the main stream, drainage ditches, or any other drainage facilities or systems. D. If a subdivision proposal or other proposed new development is in a flood-prone area, any such proposals shall be reviewed to assure that (1) all such proposals are consistent with the need to minimize damage with- in the flood-prone area, (2) all public utilities and facilities, such as sewer, gas, electrical, and water systems are located and constructed to minimize or eliminate flood damage and (3) adequate drainage is provided to reduce exposure to flood hazards. E. All persons wishing to develop in the City of Wheat Ridge shall obtain, review and reasonably utilize any base flood elevation data avail- able from Federal, State, or other sources, until such other data has been provided by the Federal Insurance Administrator, as criteria for requiring that (1) all new construction and substantial improvements of residential structures have the lowest floor (including basement) elevated to or above the base flood levels and (2) all new construction and substantial improve- ments of non-residential structures have the lowest floor (including base- ment) elevated or flood proofed to or above the base flood level. 4.4 Description of uses. Permitted uses. The following open uses shall be permitted within the area of special flood hazard to the extent that they are not prohibited in a particular area by any underlying zoning ordinance. A. Agricultural uses such as: general farming, pasture, truck farming, forestry, sod farming and wild crop harvesting; B. Industrial-commercial uses such as: loading areas, parking areas, airport landing strips and storage yards for equipment or machinery easily moved or not subject to flood damage; C. Public and private recreational uses not requiring "permanent or temporary structures" designed for human habitation such as: parks, swimming areas, golf courses, driving ranges, picnic grounds, wildlife and nature preserves, game farms, fish hatcheries, shooting preserves, target ranges and hunting, fishing and hiking areas; - 4 - ORD. NO. 255 Series of 1978 D. Utility facilities such as: flowage areas, transmission lines, pipelines, water monitoring devices, roadways and bridges. E. Minor or accessory uses approved by the Department of Community Development as from time to time delineated by a resolution of the city council. 4.5 Special exemptions. Any use enumerated in this section may be permitted only upon application to the Department of Community Development and the issuance of a special exception permit by the Board of Adjustment as provided in Section 6.5, Special Exception Permits of this ordinance. A. "Structures" accessory to open uses permitted in Section 4.4 of this ordinance, whether temporary or permanent may be permitted only upon a determination by the board of adjustment pursuant to a finding under the procedure required by Section 6.4 of this ordinance that: (1) Structures will not be designed for human habitation; (2) Structures will have a low flood damage potential; (3) The structure or structures, if permitted, will be constructed and placed on the building site so as to offer the minimum obstruction to the flow of flood waters; (a) Whenever possible, structures will be constructed with the longitudinal axis parallel to the direction of flow of flood waters, and (b) So far as practicable, structures will be placed so their longitudinal axes are approximately on the same line as those of adjoining structures. (4) Structures will be firmly anchored to prevent the structure or building from floating away and thus threatening to further restrict bridge openings and other restricted sections of the stream or river; and (5) Service facilities such as electrical equipment will be at or above the flood protection elevation for the particular area. (6) If the structures are to be permitted, evidence must be submitted by an engineer competent in open channel hydraulics that there will be no significant alteration of the one (1) percent flood flow caused by these structures. B. Other structures which are temporary or permanent for people, in- cluding mobile homes, may be permitted only upon a finding by the Board of Adjustment that: (1) Such structures shall comply with Section 4.5A (3), (4), and (5) of this ordinance. (2) The first floor, or basement floor of any structure to be erected, constructued, reconstructed on fill at or above a point two (On) feet above the 100-year flood elevation for the particular area and the fill shall extend at such elevation at least fifteen (15) feet beyond the limits of any structure or building erected thereon. C. Fills or deposition of materials may be permitted only upon a finding by the Board of Adjustment that: (1) Any fill or deposition of materials will comply with Section 4.3 Special Provisions, of this ordinance, and (2) The fill or deposition of materials will have some beneficial purpose and the amount thereof will not be greater than is necessary to achieve that purpose, as demonstrated by a plan submitted by the owner showing the final dimensions of the proposed fill or other material and the use to which the filled land will be put; - 5 - ORD. NO. 255 Series of 1978 (3) The fill or deposition of materials does not imprudently reduce the flood storage capacity of the waterway unless a permit has been granted by the City of Wheat Ridge and other requirements of this section are met; and the fill or deposition of materials does not en- croach on that portion of the flood plain which would have significant and perceptible flow during the flood, and which for that reason would help convey the flood waters. Any additional filling reduces the hy- draulic capacity and requires appropriate hydraulic studies and a re- view of the urban impact of such reduction. (4) The fill or other materials will be protected against erosion by riprap, strong vegetative cover or bulkheading. (5) It is demonstrated by an engineer competent in open channel hydraulics that the fill or other material will not significantly alter the flow of the one (1) percent flood. D. The storage or processing of materials that are buoyant, flam- mable, explosive or in times of flooding, could be injurious to human, animal or plant life,shall be at or above the flood protection elevation for the particular area or "flood proofed" in compliance with Section 6.4E Conditions attached to Special Exception Permits of this ordinance. Solid waste disposal facilities, such as junkyards or areas for the dumping of refuse shall also require a permit from the City of Wheat Ridge. E. Uses very similar in nature to permitted uses may be allowed provided that they are consistent with the provisions of this ordinance. (Ord. No. 126, Sections 3,4; Ord. No. 198, Section 1). Sec. 5.0. Exemptions. 5.1 Generally. Any building or structure as to which satisfactory proof shall be presented to the Board of Adjustment, as established by the City Council , that the present or proposed situation of such building or structure is reasonably necessary for the convenience or welfare of the public shall be exempt from the operation of this ordinance. Sec. 6.0. Administration. 6.1 Director of Community Development of the City of Wheat Ridge. The ICU V [ffli~ MHA791 ~Ihll the provisions of this ordinance. 6.2 Flood plain modification permit. A flood plain modification permit must be obtained from the Director of Community Development before any new land use subject to the provisions of this ordinance may be initiated. 6.3 Mapping disputes. The following procedure shall be used by the Board of Adjustment in deciding contested cases in which the location of a district boundary is disputed: A. In all cases the person contesting the location of boundary shall be given a reasonable opportunity to present the Board and to submit his own technical evidence if he so Board shall not allow deviations from the boundary line as the evidence clearly and conclusively established that the of the line is incorrect. the district t his case to desires. The mapped unless mapped location - 6 - ORD. NO. 255 Series of 1978 6.4 Special exception permits. A. Application. Any use listed in this ordinance as requiring aspecial exception perms may be allowed only upon application to the Director of Com- munity Development and issuance of a special exception permit by the Board of Adjustment following a public hearing. B. Procedure to be followed. Upon receiving an application for aspecial excepts involving e use of fill, construction of structures, or storage of materials, the Board shall, prior to rendering a decision thereon, obtain the opinion of the Director of Community Development and: (1) Require the applicant to submit, at the time of application, a plan certified by a registered engineer, competent in open-channel hydraulics, which accurately locates the flood plain proposal with respect to the district limits, channel of stream, existing flood plain develop- ments, together with all pertinent information such as the nature of the proposal; legal description of the property, fill limits and elevations; building floor elevations; and flood proofing measures, and a report covering the effects of the proposed construction to the flood upon other nearby residents of the flood plain. In addition, all subdivision pro- posals and other proposed new developments greater than 50 lots or 5 acres, whichever is the lesser, which are located in an area of special flood hazard, shall include within such propsals base flood elevations. (2) Require the applicant to furnish such of the following addi- tional information as is deemed necessary by the Board for the evaluation of the effects of the proposal upon flood flows and flood plain storage and to render a decision on the proposed flood plain use: (a) A typical valley cross-section showing the channel of the stream, the flood plain adjoining each side of the channel, cross- sectional area to be occupied by the proposed development, and high water information. (b) Plan (surface view) showing elevations or contours of the ground; pertinent structure, fill or storage elevations; size, loca- tion and spatial arrangement of all proposed and existing structures on the site: location and elevations of streets, water supply, sanitary fa- cilities, and soil types and other pertinent information. (c) Profile showing the slope of the bottom of the channel or thalweg of the stream. (d) Specifications for building construction and materials, "flood proofing," filling, dredging, grading, channel improvement, storage of materials, water supply, and sanitary facilities. C. Factors upon which the decision of the Board of Adjustment shall be based. The determination of the oard on each special exception per- mit shall be based on the effects of the proposed project with respect to the objectives and purpose of this ordinance as stated in Section 1.0, Purnnse. of this ordinance. D. The Board shall not act on an application in the manner above described within sixty (60) days from receiving the application. E. Conditions attached to special exception permits. Upon consi- deration of the factors listed above and purposes of this ordinance, the Board of Adjustment shall attach such conditions, in addition to those required by special permits, as it deems necessary in furthering the purposes of this ordinance. Such conditions may include specifications for, without limitation because of specific enumeration; modification of sewage disposal and water supply facilities, modification of other waste disposal methods and facilities, landscaping periods of operation, oper- ational controls, sureties, deed restriction and adequate flood proofing. - 7 - ORD. NO. 255 Series of 1978 (1) Floodproofing. Special exception requiring flood proofing measures such as the following shall be designed consistent with the flood protection elevation for the particular area as described in the special provisions, Section 4.3; and flood velocities, forces and other factors associated with the flood protection elevation. The Board shall require that the applicant submit a plan or document certified by a regis- tered professional engineer that the flood proofing measures are con- sistent with the flood protection elevation for the particular area. (a) Anchorage to resist flotation and lateral movement. (b) Installation of watertight doors, bulkheads and shutters. (c) Reinforcement of walls to resist water pressures. (d) Use of paints, membranes or mortars to reduce seepage of water through walls. (e) Addition of mass or weight to structures to resist flotation. (f) Installation of pumps to lower water levels in structures. (g) Construction of water supply and waste treatment systems to prevent the entrance of flood waters. (h) Pumping facilities for subsurface drainage systems for buildings to relieve external foundation wall and basement floor pressures. (i) Construction to resist rupture or collapse, caused by water pressure or floating debris. (j) Cutoff valves on sewer lines or the elimination of gravity flow basement drains. Furthermore, measures must be taken to ensure that the construction does not in any way cause the one (1) per- cent flood to become more damaging to other residents on the flood plain. (2) Evacuation plan. Any development plan or subdivision which contains mobile homes must prepare and have approved an evacuation plan. Said planshall indicate all alternate vehicular access and escape routes and a copy must be filed with the Civil Defense Coordinator of the City of Wheat Ridge. This requirement shall apply to all developments and sub-divisions containing mobile homes and which lie within Zone A as shown on the Flood Insurance Rate Map (FIRM) as referenced in Section 2.4 of this ordinance. Sec. 7.0. Certificate of complaince. 7.1 No vacant land shall be occupied or used and no building hereafter erected, altered or moved onto the flood plains of any watercourse shall be occupied until a certificate of compliance shall have been issued by the Director of Community Development. Z. z The Director of Community Development shall w8sUW th6 ~l; cant to submit a certification by a registered professional engineer that the finished fill and building floor elevations, flood proofing measures, or other flood protection factors were accomplished in compliance with the provisions of this ordinance. The Director of Community Development shall within ten (10) days after receipt of such certification from the applicant issue a certificate of compliance only if the building or premises and the proposed use thereof conform with all the requirements of this ordinance. Said certificate, along with the issued certificate of compliance shall be kept on record in the office of the Department of Community Development. - 8 - ORD. NO. 255 Series of 1978 Sec. 8.0. Enforcement and penalties. 8.1 Every structure, building, fill or development placed or maintained within any flood plain in violation of this ordinance is a public nuisance and the creation thereof may be enjoined and maintenance thereof may be abated by action at suit of the City of Wheat Ridge, the state or any citi- zen thereof. Any person who places or maintains any structure, building, fill or development within any flood plain in violation of this ordinance shall be guilty of a misdemeanor and upon conviction thereof, shall be fined not more than three hundred ($300.00) dollars or imprisoned not more than ninety (90) days or both. Each day during which such violation exists is a separate offense. Sec. 9.0. Amendments. 9.1 The City Council of the City of Wheat Ridge, Colorado, may from time to time, alter, supplement or change the district boundaries and the regulations contained in this ordinance in the manner provided by law. A. Amendments to this ordinance may be made on petition of any interested party in accordance with the provisions of the Colorado Revised Statutes. Sec. 10.0. Definitions. Unless specifically defined below, words or phrases used in this ordi- nance shall be interpreted so as to give them the meaning they have in common usage and to aive this ordinance its most reasonable application. 10.1 Appeal. A request for a review of any interpretation by the Zoning Administrator (or his representative) of any provision of this ordinance or a request for a variance, from said provisions. 10.2 Area of shallow flooding. A designated AO or VO zone on the Flood Insurance Rate Map (FIRM). The base flood depths range from one to three feet; a clearly defined channel does not exist; the path of flooding is unpredictable and indeterminate; and, velocity flow may be evident, 10.3 Area of special flood hazard. The land in the flood plain within a community subject to a one 1 percent or greater chance of flooding in any given year. 10.4 Base Flood. The flood having a one percent chance of being equalled or exceeded in any given year. 10.5 Board. The Board of Adjustment of the City of Wheat Ridge. 10.6 Channel. A natural or artificial watercourse of perceptible extent, with definite bed and banks to conduct continuously or periodically flowing water. Channel flow thus is that water which is flowing within the limits of the defined channel. 10.7 Development. Any man-made change to improved or unimproved real estate, including but not limited to buildings or other structures, mining, dredging, filling, grading, paving, excavation or drilling operations lo- cated within the area of special flood hazard. 10.8 Encroachment lines. Limits of obstruction to flood flows. These lines are generally parallel to the stream. The lines are established by assuming that the area landward (outside) of the encroachment lines may be ultimately developed in such a way that it will not be available to con- vey flood flows. The stream channel and adjoining flood plains between the lines will be maintained as open space and will be adequate to convey the 100-year flood without adversely increasing flood heights, such in- crease under any condition not exceeding one foot. - 9 - ORD. NO. 255 Series of 1978 10.9 Equal degree of encroachment. Established by considering the effect of encroachments on the hydraulic efficiency of the flood plain along a significant reach of the stream, on both sides. 10.10 Existing mobile home ark or mobile home subdivision A parcel (or contiguous parcels of land divided into two or more mobile home lots for rent or sale for which the construction of facilities for servicing the lot on which the mobile home is to be affixed (including, at a mini- mum, the installation of utilities, either final site grading or the pouring of concrete pads, and the construction of streets) is complete before the effective date of this ordinance. 10.11 Expansion to an existing mobile home park or mobile home subdivision. The preparation of additional sites by the construction of facilities for servicing the lots on which the mobile homes are to be affixed (including the installation of utilities, either final site grading or pouring of con- crete pads, or the construction of streets). 10.12 Flood or Flooding. A general and temporary condition of partial or complete inundation of normally dry land areas from the unusual and rapid accumulation or runoff of surface waters from any source, 10.13 Flood Insurance Rate Map (FIRM). The official map on which the Federal Insurance Administration has delineated both the areas of special flood hazards and the risk premium zones applicable to the community. 10.14 Flood Insurance Study. The official report provided by the Fed- eral Insurance Administration that includes flood profiles, the Flood- Boundary-Floodway Map and the water surface elevation of the base flood. 10.15 Flood Plain. Any land area susceptible to being inundated by water from any source. 10.16 Flood regulatory area. That portion of the flood plain subject to inundation by the 100-year flood. Its width is determined by the 100-year flood. Its length or reach is determined by natural bounds such as an ocean or lake, or by structures such as a dam or bridge, or by political or legal bounds. 10.17 Flood storage area. That portion of the regulatory area that may serve as a temporary storage area for flood waters from the 100,-year flood and that lies landward of the floodway. 10.18 Flood storage district. That area represented by the flood storage area which has been hydraulically defined and shown on the official Flood Plain Map of the City of Wheat Ridge. It exists only after appropriate action of the board of directors of the Urban Drainage and Flood Control District. 10.19 Floodway district. That area represented by the floodway which has been hydraulically defined and shown on the official Flood Plain Map of the City of Wheat Ridge. 10.20 Flood profile. A graph or a longitudinal profile showing the relationship of the water surface elevation of a flood event to location along a stream or river. 10.21 Flood proofing. A combination of structural provisions, changes or adjustments to properties and structures subject to flooding primarily for the reduction or elimination of flood damages to properties, water and sanitary facilities, structures and contents of buildings in a flood hazard area. - 10 - ORD. NO. 255 Series of 1978 10.22 Flood protection elevation. An elevation one foot above the ele- vation or "flood profile" of the 100-year flood under existing channel and flood plain conditions. It is one foot above the elevation of the flood for the flood regulatory district as shown on the official Flood Plain Map of the City of Wheat Ridge. 10.23 Flood stage. For purposes of this ordinance, the term is used to mean the height of elevation of a flood as referred to some datum. For other purposes it is commonly used to refer to the elevation at which a stream will overtop its normal stage banks, 10.24 Habitable floor. Any floor usable for living purposes, which includes working, sleeping, eating, cooking or recreation, or a combination thereof. A floor used only for storage purposes is not a "habitable floor." 10.25 Hundred-gear flood. One that has a frequency of occurrence of one hundred 100 years determined from an anlysis of floods on a particular watercourse and other watercourses in the same general region, It has about a one percent chance of occurring in any given year. 10.26 Mobile home. A structure that is transportable in one or more sections, bu- i o a permanent chassis and designed to be used with or with- out a permanent foundation when connected to the required utilities. It does not include a recreational vehicle or travel trailers. 10.27 New construction. Structures for which the start of construction commences on or aftee the effective date of this ordinance. 10.28 New mobile home ark or mobile home subdivision. A parcel (or contiguous parcels of land divided into two or more mobile home lots for rent or sale for which the construction of facilities for servicing the lot (including, at a minimum, the installation of utilities, either final site grading or the pouring of concrete pads and the construction of streets) is completed on or after the effective date of this ordinance. 10.29 Ordinary high water mark. The highest point on the bank of a normal stage channel at which the water level has been for a sufficient period of time to leave a definite mark. 10.30 Reach. A hydraulic engineering term to describe longitudinal segments of a stream or river. A reach will generally include the seg- ment of the flood plain where flood heights are primarily controlled by man-made or natural flood plain obstructions or restrictions. In an urban area, the segment of a stream or river between two consecutive bridge crossings would most likely be a reach. 10.31 Regulatory floodway. The channel of a river or other watercourse and the adjacent land areas that must be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation more than 0.5 feet. 10.32 Start of construction. The first placement of permanent con- struction of a constructure (other than a mobile home) on site, such as the pouring of slabs or footings or any work beyond the state of excava- tion. Permanent construction does not include land preparation, such as clearing, grading and filling, nor does it include the installation of streets and/or walkways; nor does it include excavation for a basement, footings, piers or foundations or the erection of temporary forms; 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 hereof 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 - 11 - ORD. NO. 255 Series of 1978 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 installation of utilities) is completed. 10.33 Storage capacity of a flood plain. The volume of space above an area of flood plain land that can be occupied by flood water of a given stage at a given time, regardless of whether the water is moving. Storage capacity tends to reduce downstream flood peaks. 10.34 Structure. Anything constructed or erected, the use of which requires a more or less permanent location on or in the ground. In- cludes but is not limited to objects such as buildings, factories, sheds, cabins, mobile homes and fences. 10.35 Structure, permanent. A structure which is built of such materials and in such a way that it would commonly be expected to last and remain use- ful for a substantial period of time. 10.36 Structure, temporary. 4 structure which is built of such materials and in such a way that it would commonly be expected to have a relatively short useful life, or is built for a purpose that would commonly be ex- pected to be relatively short-term. 10.37 Substantial improvement. Any repair, reconstruction, or improve- ment of a structure, the cost of which equals or exceeds 50 percent 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 "sub- stantial improvement" is considered to occur when the first alteration of any wall, ceiling, floor, or other structural part of the building com- mences, whether or not the alteration affects the external dimensions of the structure. The term does not, however, include either (1) any project for improve- ment of a structure to comply with existing state or local health, sanitary, or safety code specifications which are solely necessary to assume safe living conditions, or (2) any alteration of a structure listed on the National Register of Historic Places or a State Inventory of Historic Place, (3) any interior remodeing or refurbishing that does not involve expansion of the habitable area of the structure at the effective date of this ordinance. 10.38 Variance. A grant of relief from the requirements of this ordi- nance which permits construction in a manner that would otherwise be pro- hibited by this ordinance. 10.39 Zoning Administrator. An employee of the Department of Community Development, Planning and Zoning Division, who is assioned the responsibility by the Director of Community Development, to coordinate and deal with all aspects of this Ordinance. Sec. 11.0. Severability. 11.1 If any section, clause, provision or nortionof this ordinance is adjudged unconstitutional or invalid by a court of competent juris- diction, the remainder of this ordinance shall not be affected thereby. Sec. 12.0. Effective date. 12.1 This ordinance shall take effect and be in force thirty (30) days after publication. - 12 - Ordinance No. 255_ Series of 1978 READ, ADOPTED, AND ORDERED PUBLISHED on first reading by a vote of 5 to 0 on this 30th day of January A D. 1978 READ, ADOPTED, AND ORDERED PUBLISHED on second and final reading by a vote of 6 to 0 on this 13th day of February A D 1970J. OLIVER V. PHILLIPS, MAYOR ATTEST: CAROL F HAMPF, CITY CLE O~ -13-