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HomeMy WebLinkAbout80-24 Adopting Floodway and Flood Plain Zoning Districts and RegulationsORDINANCE NO. 80-24 AN ORDINANCE OF THE CITY COUNCIL OF THE CITY OF COSTA MESA AMENDING TITLE 13 OF THE COSTA MESA MUNICIPAL CODE ADOPTING FLOODWAY AND FLOOD PLAIN ZONING DISTRICTS AND REGULATIONS. THE CITY COUNCIL OF THE CITY OF COSTA MESA DOES HEREBY ORDAIN AS FOLLOWS: SECTION 1: The City Council of the City of Costa Mesa hereby finds and declares as follows: A. That increasing pressures and demands are being made on the use of land throughout our community. B. That the pressures are being applied to areas within the community subject to flooding from the Santa Ana River in the event of a 100 -year storm. C. That the Colbey-Alquist Flood Plain Management Act (California Water Code Division 5, Part 2, Chapter 4) finds that the responsibility for planning, adoption, and enforcement of land use regulations to accomplish flood plain management rests with local levels of government. D. Certain areas in Costa Mesa have been classified as "designated flood - way" in accordance with the Colbey-Alquist Flood Plain Management Act. Section 8411 of the California Water Code mandates that the City, as the appropriate public agency, establish necessary flood plain regulations. E. That existing zoning districts and regulations are inadequate to accomplish the effective management of flood plain land use and development. F. That adoption of regulations pertaining to flood plain land use and development is necessary to maintain the availability in the community of flood insurance in view of the National Flood Insurance Program (42 U.S.C. 4001-4128). G. That these zoning districts and regulations are necessary and proper to accomplish the purpose and intent of promoting the general health, safety, and general welfare of the public. ACCORDINGLY, the City Council of the City of Costa Mesa herewith amends Title 13 of the Costa Mesa Municipal Code by adding sections and Articles as hereinafter set forth: SECTION 2: CHAPTER II ARTICLE 17 1/2 - FLOODWAY AND FLOOD PLAIN (FP) DISTRICTS AND REGULATIONS §13-256 - PURPOSE AND INTENT The Floodway and Flood Plain Districts and regulations are intended to be applied to those areas of the City which, under present conditions, are subject to periodic flooding and accompanying hazards. The objectives of the Floodway and Flood Plain Districts include: 1. Prevention of loss of life and property and minimization of eco- nomic loss caused by flood flows. 2. Establishment of criteria for land management and land use in flood -prone areas that are consistent with the criteria promulgated by the Federal Insurance Administration for the purpose of providing flood insurance eligibility for property owners. 3. Prohibition of encroachments, new construction, or other improve- ments or development that would obstruct or divert the flow of floodwaters within a regulatory floodway. 4. Regulation and control of use of land below the elevation of the design flood flow within the remainder of the flood plain. §13-257 - APPLICATION In any base district where the district symbol is followed by, as a part of such symbol, the parenthentically enclosed symbols (FP -1) or (FP -2), or when the property is included within a designated flood hazard area shown on the adopted Flood Insurance Rate Map (Community Panel Number 060216 001 C; Preliminary Map dated July 11, 1980), or Flood Boundary and Floodway Maps as Epa published by the Federal Insurance Administration, the additional requirements, limitations, and standards contained in this Article shall apply. The land use district symbol shall constitute the "base district" and the symbol (FP -1), (FP -2), or those flood hazard zone designations on the Flood Insurance Rate Map as listed below, shall constitute the "combining district." In the event of conflicting provisions of such combined district regulations, the require- ments of the FP "Flood Plain" District shall take precedence over the require- ments of the base district. 1. These regulations are applicable as follows: a. Areas shown as (FP -1) on the Official Land Use Map and areas shown as a "floodway" on an adopted Flood Boundary and Floodway map are subject to the FP and FP -1 provisions of this Article. b. Areas shown as (FP -2) on the Official Land Use and District Maps and areas shown as A, A7, A8, All, A0, and AH on any adopted Flood Insurance Rate Map are subject to the FP, FP -2, and floodway fringe area provisions of this Article, except that where there is a conflict with the provisions of "l.a." above, those provisions are applicable. 2. Flood -hazard areas shall be identified and mapped, based upon: a. The base flood and criteria set forth by the "Flood Insurance Study for the City of Costa Mesa, California -Orange County" (pre- liminary study dated July 11, 1980). If the Federal Emergency Management Agency has not provided base flood elevations in said study, such base flood data shall be obtained from other available sources or studies meeting with City approval; or, b. The design flood as determined from engineering studies reviewed and found satisfactory by the City of Costa Mesa as approved by the City Council. -3- 3. Adoption of Flood Insurance Rate Maps and Flood Boundary and Floodway Maps as zoning district maps - Flood Insurance Rate Map, Community Panel Number 060216 001 C (Preliminary Map dated July 11, 1980) and Flood Boundary and Floodway Maps prepared in conjunction with the Flood Insurance Rate Map as published by the Federal Insurance Administration are hereby adopted as zoning district maps of the City of Costa Mesa for purposes of application of the FP "Flood Plain" District regulations only. X13-258 - DEFINITIONS The following words and phrases shall have the definition and construction set forth in this Section as used in this Article, unless otherwise provided herein: 1. Area of Shallow Flooding A designated AH or AD zone on the Flood Insurance Rate Map (F.I.R.M.) in which: a. The base flood depths range from one to three feet; b. A clearly defined channel does not exist; and c. The path of flooding is unpredictable and indeterminate. 2. Area of Special Flood Hazard The land in the flood plain within a community subject to a one percent or greater chance of flooding in any given year. 3. Base Flood The flood having a one percent chance of being equalled or exceeded in any given year. 4. Design Flood That flood against which protection is to be provided by means of land use regulation, flood protective or flood control works. For the purposes !_s of this Article, the Design Flood shall be at the 100 -year recurrence interval, corresponding to the Base Flood as defined above. 5. Development Any man-made change to improved or unimproved real estate, including but not limited to buildings or other structures, grading, or paving located within the flood hazard area. 6. Flood A general and temporary condition of partial or complete inundation of land areas from the overflow of inland and tidal waters, and the rapid accumulation of runoff of surface waters from any source and mudslides (i.e., mudflows) which are proximately caused or precipitated by accumulations of water on or under the ground. 7. Flood Hazard Area An area having flood, mudslide (i.e., mudflow) and flood - related erosion hazards, or as shown on a Sectional District Map, Flood Insurance Rate Map (F.I.R.M.) or Flood Boundary and Floodway Map. 8. Flood Insurance Rate Map (F.I.R.M.) and Flood Boundary and Floodway Map The official maps published by the Federal Insurance Administra- tion on which are delineated both the areas of special flood hazards and the risk premium zones applicable to the community. 9. Flood Insurance Study The "Flood Insurance Study for the City of Costa Mesa, California - Orange County" (preliminary study dated July 11, 1980) prepared by the Federal Insurance Administration providing flood profiles, as well as the boundaries and the water surface elevations of the base flood, including the Flood Boundary and Floodway Map. -5- 10. Flood Plain The land area adjacent to a watercourse, and other land areas susceptible to being inundated by water from any source (see definition of "Flood"). 11. Flood Proofing Any combination of structural and nonstructural additions, changes, or adjustments to structures which reduce or eliminate flood damage to real estate or improved real property, water and sanitary facilities, and struc- tures and their contents. 12. Flood Protection System Those physical structural works for which funds have been authorized, appropriated, and expended and which have been constructed speci- fically to modify flooding in order to reduce the extent of the area within a community subject to a flood hazard and the extent of the depth of associated flooding. Such a system typically includes channels, storm drains, or levees or dikes. These specialized flood modifying works are those constructed in conformance with sound engineering standards. 13. Flood Related Erosion The collapse or subsidence of land along the shore of a lake or other body of water as a result of erosion or undermining, caused by waves or currents of water exceeding anticipated cyclical levels or suddenly caused by an unusually high water level in a natural body of water, accompanied by a severe storm, or by an unanticipated force of nature, such as a flash flood or by an abnormal tidal surge, or by some similarly unusual and unforeseeable event which results in flooding. 14. Floodway The channel of a river or other watercouse and adjacent land areas that must be reserved in an open manner, and that can be designated to EM provide for the discharge of the design flood without cumulatively increasing the water surface elevation more than one foot. The floodway may also be that land area necessary for the design flood discharge for an authorized federal flood control project. 15. Floodway Fringe That area between the design flood boundary and the Floodway shown on the Flood Boundary and Floodway Map. 16. Habitable Floor Any floor usable for living purposes, which includes working, sleeping, eating, cooking, or recreation, or a combination thereof. A floor designed and used only for storage purposes is not a "habitable floor." 17. Land Use District Symbol The applicable designation for the zoning of property, contained in this Title. 18. Regulatory Floodway The floodway areas designated by the City as FP -1 overlay Districts, and/or the flooding areas delineated on the official Federal Insurance Administration "Flood Boundary and Floodway Maps" for the City of Costa Mesa. 19. Structure Anything constructed or erected requiring a fixed location on the ground or attached to something having a fixed location on the ground except business signs and other improvements of a minor character. For floodplain management purposes, "structure" means a walled and roofed building, including a gas or liquid storage tank that is principally above ground, and includes a mobilehome. -7- 20. Substantial Improvement Any repair, reconstruction, or improvement of a structure, the cost of which equals or exceeds 50 percent of the market value of the structure either (a) before the improvement or repair is started, or (b) if the struc- ture 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 alteration of any wall, ceiling, floor, or other struc- tural part of the building commences, whether or not that alteration affects the external dimensions of the structure. X13-259 - USES PERMITTED IN THE (FP-1) OVERLAY DISTRICT AND IN FLOODWAY AREAS The following uses shall be allowed in the (FP-1) overlay district and in floodway areas. 1. Permitted Uses a. Flood control channels, levees, spreading basins and grounds, roads, bridges, storm drains, and other flood control facilties and devices where the design has been approved by the Director of Environmental Management Agency and the Board of Supervisors of Orange County or the Public Services Director and the City Council of the City of Costa Mesa. b. General agricultural uses including farming or pastures provided there are no permanent structures, landfill, storage of materials or equipment or stream alterations that would result in any diversion or increase in flood levels within the designated floodway. c. Public utility transmission lines and conduits. d. Recreation areas, parks, fishing lakes, riding and hiking trails, golf courses, athletic fields, and similar open space uses not including any permanent structures or improvements. cm 2. Prohibited Uses a. Any permanent structures or buildings excepting those necessary for conveyance of flood and drainage waters and for transit of public utilities and roads. b. Dwelling units. c. Landfills, excavations, improvements, developments, or encroachments that would obstruct or create debris -catching obstacles to passage of a design flood, or cause a cumulative increase in the elevation of the design floodwater profile at any point, or would tend to broaden the flood- plain or divert flood flows out of the regulatory floodway or in any way impair the design flood conveyance capacity of the regulatory floodway or cause a potential hazard to public safety or property resulting from flood flows. d. Storage or disposal of floatable substances or materials, dangerous chemicals, explosives, flammable liquids, or other toxic materials. 3. Conditional Uses Additional uses not specifically listed above as either a per- mitted or prohibited use may be considered for approval as a conditional use, according to the procedures set forth in this Code. However, no use permit shall be approved unless the following finding can be made. a. The proposed project, alone or in combination with any existing developments, will not endanger public safety, will not restrict the carrying capacity of the regulatory floodway, will not increase flood heights, and will not increase the velocity of floodwaters. Applicants for Conditional Use Permits as provided for herein, shall be required to submit studies, plans, or other evidence prepared by a registered professional engineer or architect to support the required findings necessary for approval of the use permit. X13-260 - USES PERMITTED IN THE (FP -2) OVERLAY DISTRICT AND IN DESIGNATED FLOODWAY FRINGE AND SPECIAL FLOOD HAZARD AREAS INDICATED ON THE FLOOD INSURANCE RATE MAP 1. Permitted Uses a. All permitted uses in the (FP -1) overlay district. b. New structures and improvements, including the placement of buildings within the (FP -2) District and floodway fringe or special flood hazard areas developed in conformance with the provisions of Sections 13-261-4 through 13-261-6, inclusive. 2. Prohibited Uses a. Landfills, excavations, improvements, developments, or encroachments, that will obstruct or create debris -catching obstacles to passage of the design flood, or that cause a cumulative increase in the elevation of the design flood water profile more that one (1) foot at any point, or that will tend to broaden or direct flood flows out of the natural flood plain, or otherwise cause a potential hazard to public safety or property resulting from flood flows in the floodway fringe or special flood hazard areas. b. Storage of floatable substances or materials. c. Storage or disposal of chemicals, explosives, flammable liquids, or other toxic materials in areas or structures that have not been made f loodproof . 3. Conditional Uses Additional uses not specifically listed above as either a per- mitted or prohibited use may be considered for approval as a condiitonal use, according to the procedures set forth in this Code. However, no use permit shall be approved unless the following finding can be made: a. The proposed project, alone or in combination with any existing developments, will not endanger public safety, will not increase flood heights, and will not increase the velocity of floodwaters. -10- Applicants for Conditional Use Permits as provided for herein shall be required to submit studies, plans, or other evidence prepared by a registered professional engineer or architect to support the required findings necessary for approval of the use permit. §13-261 - PROCEDURES AND DEVELOPMENT STANDARD The following procedures and development standards shall be applied to all projects located in the (FP -1) and (FP -2) overlay Districts. 1. Review Procedures. The Development Services Director shall review projects proposed in areas subject to the FP District regulations to determine compliance with the provisions of this Article. Specific responsibil- ities shall include, but not be limited to: a. Review all development permits to determine that the permit requirements of this Ordinance have been satisfied. b. Review all permits to determine that the site is reasonably safe from flooding. c. Review all development permits to determine if the proposed development adversely affects the flood carrying capacity of the area of special flood hazard. For purposes of this Ordinance, "adversely affects" means that the cumulative effect of the proposed development when combined with all other existing and anticipated development will increase the water surface elevation of the base flood more than one foot at any point. 2. Submittal Requirements. All development, subdivision, structure, and substantial improvement proposals shall include submittal of detailed drain- age studies and plans drawn to scale showing the nature, location, dimensions, and elevation of the area in question; existing or proposed structures, fill, storage of materials, drainage facilities; and the location of the foregoing. Specifically, the following information is required: -11- a. Proposed elevation in relation to mean sea level, of the lowest habitable floor (including basement) of all structures; in Zone AO elevation of existing and proposed elevation of lowest habitable floor of all structures. b. Proposed elevation in relation to mean sea level to which any structure will be floodproofed. c. Certification by a registered professional engineer or architect that the floodproofing methods for any nonresidential structure meet the floodproofing criteria contained in this Article. d. Description of the extent to which any watercourse will be altered or relocated as a result of proposed development. Said plans, floor height information, and certifications shall be maintained on file by the Development Services Department for flood insurance reference purposes. 3. Alteration or Relocation of Watercourse. The Director of Develop- ment Services shall notify adjacent communities and the California Department of Water Resources prior to approval of any project which would alter or relocate a watercourse having an effect on the flood hazard areas shown on the Flood Insurance Rate Maps and submit evidence of such notification to the appropriate Federal Agency. Any approval action for such project shall require that maintenance is provided within the altered or relocated portion of a watercourse so that the flood -carrying capacity of the watercourse is not diminished. 4. Standards of Construction are required: In all areas of special flood hazards, the following standards -12- a. All new construction and substantial improvements shall be anchored to prevent flotation, collapse, or lateral movement of the structure. b. All new construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage using methods and practices that minimize flood damage. c. New construction and substantial improvement of any structure shall have the lowest habitable floor, including basement, elevated to or above the base flood elevation. Nonresidential structures may meet the standards in Section 13-261-4(e). Upon completion of the structure, the elevation of the lowest habitable floor including basement shall be certified by a registered professional engineer or surveyor and provided to the Development Services Director. d. New construction and substantial improvement of any struc- ture in Zone AO shall have the lowest floor, including basement, elevated to or above the depth number specified on the FIRM. If there is no depth number on the FIRM, the lowest floor, including basement, shall be elevated one foot above the crown of the nearest street. Nonresidential structures may meet the standards in Section 13-261-4(e). Upon completion of the structure, a registered professional engineer shall certify that the elevation of the structure meets this standard and such certification shall be provided to the Development Services Director. e. Nonresidential construction shall either be elevated in conformance with Section 13-261-4(c) or 13-261-4(d) or, together with attendant utility and sanitary facilities: (1) be floodproofed so that below the base flood level the structure is watertight with walls substantially impermeable to the passage of water; -13- (2) have structural components capable of resisting hydro- static and hydrodynamic loads and effects of buoyancy; and (3) be certified by a registered professional engineer or architect that the standards of this subsection are satisfied. Such certifi- cations shall be provided to the Development Services Director. 5. Standards for Utilities a. All new and replacement water supply and sanitary sewage systems shall be designed to minimize or eliminate infiltration of flood waters into the system and discharge from systems into flood waters. b. On-site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding. 6. Standards for Subdivisions a. All preliminary subdivision proposals shall identify the flood hazard area and the elevation of the base flood. b. All final subdivision plans will provide the elevation of proposed structure(s) and pads. If the site is filled above the base flood, the final pad elevation shall be certified by a registered professional engineer or surveyor and such certification shall be provided to the Development Services Director. c. All subdivision proposals shall be consistent with the need to minimize flood damage. d. All subdivision proposals shall have public utilities and facilities such as sewer, gas, electrical, and water systems located and con- structed to minimize flood damage. e. All subdivision proposals shall have adequate drainage provided to reduce exposure to flood damage. -14- 7. Findings Application for a permit may be denied where the Development Ser- vices Director is unable to make each of the following findings: a. The development will not produce a significant risk to human life in the event of the design flood. b. The development is designed and sited so as to offer minimal obstruction to the flow of floodwater. c. The development will not create a potential hazard or other- wise adversely affect property because of diversions, increased heights, or velocities of flood waters or because of increased debris, or otherwise adversely affect the safety, use, or stability of any public way, drainage channel, or adjacent property during a flood condition. Applicants for permits as provided for herein shall be required to submit studies, plans, or other evidence prepared by a registered professional engineer or architect to support the required findings necessary for approval of the permit. §13-262 - EXCEPTIONS To DESIGNATED FLOOD HAZARD AREAS The Development Services Director may determine that certain properties within a flood plain district are not required to comply with the provisions of this Article "Flood Plain" District when it can be shown that any of the follow- ing circumstances or conditions are present: 1. The zoning map includes property within an FP district that is found to be not within a flood plain area due to incorrect preparation of the zoning map or to physical alteration of surrounding property which effectively removed the subject property from the flood plain area. The Director's deter- mination shall be based on a study of topographic and design flood elevation contours on the subject property, and on such additional information as is found necessary or appropriate. -15- 2. Flood protective or flood control work, adequate to protect against the design flood and in compliance with County flood control and flood protective standards and policies, has been completed. The Director's finding shall confirm that any stream, channel, storm drain, or landfill improvements fully offset flood surface elevations established by the applicable flood plain map; and that if the property is included on a Flood Insurance Rate Map or a Flood Boundary and Floodway Map, all such flood protective or flood control work has been approved by the appropriate Federal agency and the property removed from the flood plain designation on such maps. SECTION 3: This Ordinance shall take effect and be in full force thirty (30) days from and after the passage thereof, and prior to the expiration of fifteen (15) days from its passage shall be published once in the ORANGE COAST DAILY PILOT, a newspaper of general circulation, printed and published in the City of Costa Mesa or, in the alternative, the City Clerk may cause to be pub- lished a summary of this Ordinance and a certified copy of the text of this Ordinance shall be posted in the office of the City Clerk five (5) days prior to the date of adaption of this Ordinance, and within fifteen (15) days after adoption, the City Clerk shall cause to be published the aforementioned summary and shall post in the office of the City Clerk a certified copy of this Ordi- nance together with the names of the members of the City Council voting for and against the same. PASSED AND ADOPTED this 15th day of December, 1980. ATTEST: City Clerk of the City of Costa 7 a Mayor of the City bfCos ^ Mesa APPROVED AS TO FORM CITY ATTORNEY -16- STATE OF CALIFORNIA ) COUNTY OF ORANGE ) CITY OF COSTA MESA ) I, EILEEN P. PHINNEY, City Clerk and ex -officio Clerk of the City Council of the City of Costa Mesa, hereby certify that the above and foregoing Ordinance No. 80-24 was introduced and considered section by section at a regular meeting of said City Council held on the 1st day of December, 1980, and thereafter passed and adapted as a whole at a regular meeting of said City Council held on the 15th day of December, 1980, by the following roll call vote: AYES: COUNCIL MEMBERS: Schafer, Hall, Hertzog, McFarland, Johnson NOES: COUNCIL MEMBERS: None ABSENT: COUNCIL MEMBERS: None IN WITNESS WHEREOF, I have hereunto set my hand and affixed the Seal of the City of Ccsta Mesa this 16th day of December, 1980. City Clerk and ex -off icio Clerk of e City Council of the City of Costa sa -17-