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HomeMy WebLinkAbout07991 -. ORDINANCE NO. 799 (1979 Series) AN ORDINANCE OF THE CITY OF SAN LUIS OBISPO ADOPTING MUNICIPAL CODE ARTICLE IX, CHAPTER 8, SECTIONS 9800 THROUGH 9816, FLOOD DAMAGE PREVENTION REGULATIONS. WHEREAS, the Legislature of the State of California has delegated the responsibility to local governmental units to adopt regulations designed to promote the public health, safety and general welfare of its citizenry; and WHEREAS, the City Council of the City of San Luis Obispo makes the following findings of fact: (1) The flood hazard areas of San Luis Obispo are subject to periodic inundation which could result in loss of life and property, health and safety hazards, disruptions of commerce and governmental services, extraordinary public expenditures for flood protection and relief, and impairment of the tax base, all of which adversely affect the public health, safety and general welfare. (2) These flood losses are contributed to by the cumulative effect of obstructions in areas of special flood hazards which increase flood heights and velocities, and when inadequately anchored, damage uses in other areas. Uses that are inadequately protected from flood damage also contribute to flood loss. NOW, THEREFORE, BE IT ORDAINED by the Council of the City of San Luis Obispo as follows: SECTION 1. Chapter 8, Sections 9800 through 9816, FLOOD DAMAGE PREVENTION REGULATIONS, is hereby added to Article IX of the Municipal Code to read in full as follows: (See attached text.) SECTION 2. This ordinance, together with the ayes and noes, shall be published once in full, at least three (3) days before its final passage, in the Telegram- Tribune, a newspaper published and circulated in said City, and the same shall go into effect at the expiration of thirty (30) days after its said final passage. 0 799 Ordinance No. 799 (1979 Series) INTRODUCED AND PASSED TO PRINT at a regular meeting of the City Council on the 20th day of February 1979, on motion of Councilman Settle , seconded by Councilman Dunin and on the following roll call vote: AYES: Councilmen Dunin, Jorgensen, Petterson, Settle and Mayor Schwartz NOES: None ABSENT: None ATTEST: �I . . c Approved as to form: City Attorney ktm 1/23/79 Approved as to content: 'Ci y` Administrative Officer ORDINANCE NO. 799 (1979 Series) FINALLY PASSED this 5th day of March , 1979 , on motion of Councilman Jorgensen, seconded by Councilman Settle, on the following roll call vote: AYES: Councilmen Dunin, Jorgensen, Petterson, Settle and Mayor Schwartz NOES: None ABSENT: None ATTEST: J. itzpatrick, CITY CLERK ARTICLE IX, Chapter 8 FLOOD DAMAGE PREVENTION REGULATIONS SECTION 9800. STATEMENT OF PURPOSE 9801. METHODS OF REDUCING FLOOD LOSSES 9802. DEFINITIONS 9803. LANDS TO WHICH THIS CHAPTER APPLIES 9804. BASIS FOR ESTABLISHING THE AREA OF SPECIAL FLOOD HAZARD 9805. AREAS OF SPECIAL FLOOD HAZARD AND THEIR INSURANCE CRITERIA (a) AO Zones (b) A Zones (c) B Zones (d) C Zones 9806. SOURCE OF DESIGNATIONS AND LOCAL EXCEPTIONS 9807. COMPLIANCE 9808. INTERPRETATION 9809. WARNING AND DISCLAIMER OF LIABILITY 9810. ESTABLISHMENT OF DEVELOPMENT PERMIT 9811. DESIGNATION OF THE CITY ENGINEER 9812. DUTIES AND RESPONSIBILITIES OF THE CITY ENGINEER 9813. VARIANCE PROCEDURE 9814. GENERAL STANDARDS FOR FLOOD HAZARD REDUCTION 9815. SPECIFIC STANDARDS 9816. FLOODWAYS ARTICLE IX, Chapter 8 FLOOD DAMAGE PREVENTION REGULATIONS SECTION 9800. STATEMENT OF PURPOSE. It is the purpose of this chapter to promote the public health, safety and general welfare, and to minimize public and private losses due to flood conditions in specific areas by provisions designed: (a) To protect human life and health; (b) To minimize expenditure of public money for costly flood control projects; (c) To minimize the need for rescue and relief efforts associated with flooding and generally undertaken at the expense of the general public; (d) To minimize prolonged business interruptions; (e) To minimize damage to public facilities and utilities such as water and gas mains, electric, telephone and sewer lines, streets and bridges located in areas of special flood hazard; (f) To help maintain a stable tax base by providing for the second use and development of areas of special flood hazard so as to minimize future flood blight areas; (g) To ensure that potential buyers are notified that property is in an area of special flood hazard; and (h) To ensure that those who occupy the areas of special flood hazard assume responsibility for their actions. SECTION 9801. METHODS OF REDUCING FLOOD LOSSES. In order to accomplish its purposes, this chapter includes methods and provisions for: (a) Restricting or prohibiting uses which are dangerous to health, safety, and property due.to water or erosion hazards, or which result in damaging increases in erosion or in flood heights or velocities; (b) Requiring that uses vulnerable to floods, including facilities which serve such uses, be protected against flood damage at the time of initial construction; (c) Controlling the alteration of natural flood plains, stream channels, and natural protective barriers, which help accommodate or channel flood waters; (d) Controlling filling, grading, dredging, and other development which may increase flood damage; and (e) Preventing or regulating the construction of flood barriers which will unnaturally divert flood waters or which may increase flood hazards in other areas. SECTION 9802. DEFINITIONS. The following words and phrases whenever used in this chapter shall be construed as defined in this section: (a) Appeal shall mean a request for a review of the City Engineer's interpretation of any provision of this chapter or a request for a variance. (b) Area of shallow flooding shall mean a designated AO 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. (c) Area of special flood hazard shall mean the land in the flood plain within a community subject to a one percent (1 %) or greater chance of flooding in any given year. (d) Base flood or 100 year flood shall mean the flood,having a one per - cent (1 %) chance of being equalled or exceeded in any given year. (e) Development shall mean 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 located within the area of special flood hazard. (f) Existing mobile home park or mobile home subdivision shall mean 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 minimum, the installation of utilities, either final site grading or the pouring of concrete pads, and the construction of streets) is completed before the effective date of this chapter. (g) Expansion of an existing mobile home park or mobile home subdivision shall mean 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 concrete or the construction of streets). (h) 500 year flood shall mean the flood having a two- tenths percent (0.2 %) chance of being equalled or exceeded in any given year. (i) Flood or flooding shall mean a general and temporary condition of partial or complete inundation of normally dry land areas from: (1) Overflow of inland waters and /or (2) The unusual and rapid accumulation or runoff of surface waters from any source. (j) Flood Insurance Rate Map (FIRM) shall mean 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. (k) Flood Insurance Study shall mean the official report provided in which the Federal Insurance Administration has provided flood profiles, as well as the Flood Hazard Boundary - Floodway Map and the water surface _ elevation of the base flood._ (1) Floodproofing - Walls, dikes, dams, & floodgates together with attendant utility and sanitary facilities shall be designed so that below the base flood level the structure is water tight with walls substantially impermeable to the passage of water and with structured components having the capability of resisting hydrostatic and hydro- dynamic loads and effects of buoyancy. (m) Floodway shall means 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 one foot (11) maximum. (n) Habitable floor shall mean any floor usable for living purposes, which includes working, sleeping, eating, cooking, or recreation, or a com- bination thereof. A floor used only for storage purposes is not a "habitable floor _ (o) Mobile home shall mean 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. It does not include recreational vehicles or travel trailers. (p) New construction shall mean structures for which the "start of construction" commenced on or after the effective date of this chapter. (q) New mobile home park or mobile home subdivision shall mean 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 chapter. (r) Start of construction shall mean the first placement of permanent construction of a structure (other than a mobile home) on a site, such as the pouring of slabs or footings or any work beyond the stage of excavation. Permanent construction does not include land preparation, such as clearing, grading, and filling, nor does it include the installation of streets and /or walkways; nor:does it include excavation for a basement, footings, piers or foundations or the erection of temporary forms; nor does it include the instal- lation on the property of accessory buildings, such as garages or sheds not occupied as dwelling units or not as part of the main structure. For a structure (other than a mobile home) without a basement or poured footings, the "start of construction" includes the first permanent framing or assembly of the structure or any part thereof on its piling or foundation. For mobile homes within mobile home parks or mobile home subdivisions, "start of construction" is the date on which the construction of facilities for servicing the site on which the mobile home is to be affixed (including, at a minimum;. the construction of streets, either final site grading or the pouring of concrete pads, and installation of utilities) is completed. (s) Structure shall mean a walled and roofed building or mobile home that is principally above ground. (t) Substantial improvement shall mean any repair, reconstruction, or improvement of a structure, the cost of which eauals or exceeds fifty percent (50 %) of the market value of the structure either before the improvement is begun, or, 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 alteration of any wall, ceiling, floor,_ or other structural part o_f_the building commences, whether or not that alteration affects the external dimensions of the structure. The "term shall not, however, include either _ _ (1) Any project for improvement of a structure to comply with existing state or local health, sanitary, or safety code specifications which are solely necessary to assure safe living conditions; or (2) Any alteration. of a structure listed on the National Register of Historic Places, the State Inventory of Historic Places or the City of San Luis Obispo Historical $ Architectural Element of the General Plan. (u) Variance shall mean a grant of relief from the requirements of this chapter which permits construction in a manner that would otherwise be prohibited by this chapter. SECTION 9803. LANDS TO WHICH THIS CHAPTER APPLIES. This chapter shall apply to all areas of special flood hazards within the jurisdiction of the City of San Luis Obispo. SECTION 9804. BASIS FOR ESTABLISHING THE AREA OF SPECIAL FLOOD HAZARD. The areas of special flood hazards identified by the Federal Insurance Administration in a scientific and engineering report entitled "The Flood Insurance Study for the City of San Luis Obispo, California," with accompanying Flood Insurance Rate Maps, is hereby adopted by reference and declared to be a part of these regulations. The Flood Insurance Study is on file in the Office of the City Engineer, 990 Palm Street, San Luis Obispo, California, is available for inspection during regular business hours, and may be amended from time to time by resolution of the City Council. National Geodetic Vertical Datum of 1929 is the basis for the elevations in the report. SECTION 9805. AREAS OF SPECIAL FLOOD HAZARD AND THEIR INSURANCE CRITERIA. Areas of special flood hazard and their Flood Insurance Criteria are defined as follows: (a) AO Zones: Areas of one hundred (100) year shallow flooding; flood depth of one to three feet (1 -31); product of flood depth (in feet) and velocity (feet per second) less than 15. Areas of shallow flooding with depths from one foot to three feet will be designated as an AO Zone with an elevation depth rounded off to the nearest foot, i.e., 1, 2, or 3 feet. In the AO zone, for flood plain management purposes, the lowest floor including basement of new residential structures, shall be one foot above the flood elevation determined by adding the elevation of the highest point on the lot adjacent to the building to the depth number specified by the zone designation. For nonresidential structures, the lowest floor including basement must be flood proofed or raised one foot (11)above the flood elevation determined in the same manner as described for residential structures. (b) A Zones (A -1 to A -30): Areas of one hundred (100)year flooding; base flood elevations and flood hazard factors have been determined. A Zones shall have all residential structures finished first floor elevation raised a minimum of one foot (11) above the 100 year flood elevation. Non - residential area may either have finished first floor elevation raised • minimum of one foot (11) above the 100 year flood elevation or flood proofed • minimum of one foot (11) above the 100 year flood elevation. (c) B Zones: Areas between limits of 100 year flooding and 500 year flood- ing; areas of 100 year shallow flooding where depths are less than one foot (11). No flood insurance is required, but all projects within this zone must be reviewed by the Engineering Division to determine whether proposed finished first floor elevation is about 100 year flooding elevations. (d) C Zones: Areas outside of 500 year flooding. No flood insurance or staff review for finished first floor slab height is required. SECTION 9806. SOURCE OF DESIGNATIONS AND LOCAL EXCEPTIONS. (a) All 100 year flooding and building elevations as referred to in Section 9805 above, are based on the Flood Insurance Study done by the Corps of Engineers for the U. S. Department of Housing $ Urban Development - Federal Insurance Administration as cited in Section 9804. (b) Local experience and historical data shall take precedence in all zones where there may be localized flooding that is not shown on the Flood Insurance Study cited in Section 9804. SECTION 9807. COMPLIANCE. No structure or land grading shall hereafter be const :ucted, located, extended, converted or altered without full compliance with the terms of this chapter and other applicable regulations. SECTION 9808. INTERPRETATION. In the interpretation and application of this chapter, all provisions shall be: (a) Considered as minimum requirements; (b) Liberally construed in favor of the governing body; and (c) Deemed neither to limit nor repeal any other powers granted under state statutes. SECTION 9809. WARNING AND DISCLAIMER OF LIABILITY. The degree of flood protection required by this chapter is considered reasonable for regulatory purposes and is based on scientific and engineering considerations. Larger floods can and will occur on rare occasions. Flood heights may be increased by man -made or natural causes. This chapter does not imply that land outside the areas of special flood hazards or uses per- mitted within such areas will be free from flooding or flood damages. This chapter shall not create liability on the part of the City of San Luis Obispo, any officer or employee thereof, or the Federal Insurance Administration, for any flood damages that result from reliance on this chapter or any admin- istrative decision lawfully made thereunder. SECTION 9810. ESTABLISHMENT OF DEVELOPMENT PERMIT. A development permit shall be obtained before construction or development begins within any area of special flood hazard established in Section 9805. Application for a development permit shall be made on forms furnished by the Community Development Department, and may include, but not be limited to, plans, in duplicate, drawn to scale, showing the nature, location, dimensions, and elevations 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: (a) Elevation in relation to mean sea level, using 1929(NGVD), of the lowest floor (including basement) of all structures; (b) Elevation in relation to mean sea level, using 1929(NGVD), to which any structure has been floodproofed; (c) Certification by a registered professional engineer or architech that the floodproofing methods for any nonresidential structure meet the flood - proofing criteria in Section 9815(b)(3); (d) Description of the extent to which any watercourse will be altered or relocated as a result of proposed development; and (e) Plans for any walls to be used to enclose space below the base flood level. (f) Prior to occupancy the City Engineer shall be supplied with written certification by a registered land surveyor or civil engineer that the lowest floor,.elevation or floodproofed elevation complies with this chapter. SECTION 9811. DESIGNATION OF THE CITY ENGINEER. The City Engineer is hereby appointed to administer and implement this chapter by granting or denying development permit applications in accordance with its provisions. SECTION 9812. DUTIES AND RESPONSIBILITIES OF THE CITY ENGINEER. The duties of the City Engineer shall include, but are not limited to: (a) Permit Review (1) Review all development permits to determine that the permit requirements of this chapter have been satisfied. (2) Review all development permits to determine that all building sites are reasonably safe from flooding. (3) Advise all applicants that other permits may be required from federal, state and local governmental agencies. (4) Review all development permits in the area of special flood hazard to determine if the proposed development adversely affects the flood carrying capacity of the -area of special flood hazard. For the purposes of this chapter, "adversely affects" means that the cumulative effect of the proposed development and other preceding developments will not in- crease the water surface elevation of the base flood more than one foot at any point. (b) Use of Other Base Flood Data. When base flood elevation data has not been provided in accordance with Section 9804, BASIS FOR ESTABLISHING THE AREAS OF SPECIAL FLOOD HAZARD, the City Engineer shall obtain, review, and reasonably utilize any base flood elevation data available from a federal, state or other source, in order to administer Sections 9815(a) SPECIFIC STANDARDS, Residential Construction, and 9815(b) SPECIFIC STANDARDS, Nonresidential Construction. (c) Information to be Obtained and Maintained. (1) Indicate base flood elevation. (2) Obtain and record the actual elevation (in relation to mean sea level,.1929 NGVD) of the lowest habitable floor (including basement) of all new or substantially improved structures. (3) For all new or substantially improved floodproofed structures; (aa) Verify and record the actual elevation (in relation to mean sea level, 1929 N_GVD) , and (bb) Maintain the floodproofing certifications required in Section 9815 (b) (3) . (4) Maintain for public inspection all records pertaining to the provisions of this chapter. (d) Alteration of Watercourses. (1) Notify adjacent communities and the California State Department of Water Resources prior to any alteration or relocation of a watercourse, and submit evidence of such notification to the Federal Insurance Administration. (2) Require that maintenance is provided within the altered or relocated portion of said watercourse so that the flood carrying capacity is not diminished. (e) Interpretation of FIRM Boundaries. Make interpretations where needed, as to the exact location of the boundaries of the areas of special flood hazards (for example, where there appears to be a conflict between a mapped boundary and actual field conditions). The person contesting the location of the boundary shall be given a reasonable opportunity to appeal the interpretation as provided in Section 9813. SECTION 9813. VARIANCE PROCEDURE. (a) Appeals (1) The City Council shall hear and decide appeals and requests for variances from the requirements of this chapter. (2) The City Council shall hear and decide appeals when it is alleged there'is an error in any requirement, decision or determination made by the City Engineer in the enforcement or administration of this chapter. (3) In passing upon such applications, the City Council shall con- sider all technical evaluations, all relevant factors, including all possible environmental impacts, standards specified in other sections of this chapter; and (aa) The danger that materials may be swept onto other lands to. the injury of others; (bb) The danger to life and property due to flooding or erosion damage; (cc) The susceptilbility of the proposed facility and its contents to flood damage and the effect of such damage on the individual owner; (dd) The importance of the services provided by the proposed facility to the community; (ee) The necessity to the facility of a waterfront location, where applicable; (ff) The availability of alternative locations, for the proposed use which are not subject to flooding or erosion damage; (gg) The compatibility of the proposed use with existing and anticipated development; (hh) The relationship of the proposed use to the comprehensive plan and flood plain management program of that area; (ii) The safety of access to the property in times of flood for ordinary and emergency vehicles; (jj) The expected heights, velocity, duration, rate of rise, and sediment transport of the flood waters and the effects of wave action, if applicable, expected at the site; and (kk) The costs of providing governmental services during and after flood conditions, including maintenance and repair of public utilities and facilities such as sewer, gas, electrical, and water systems, and streets and bridges. (4) Generally, variances may be issued for new construction and sub- stantial improvements to be erected on a lot of one -half acre or less in size continguous to and surrounded by lots with existing structures constructed below the base flood level, providing items (aa) through (kk) of subsection (a)(3) above, have been fully considered. As the lot size increases beyond the one -half acre, the technical justfiication required for issuing the variance increases. (5) Upon consideration of the factors of subsection (a)(3) above, and the purposes of this chapter, the City Council may attach such conditions to the granting of variances as it deems necessary to further the purposes of this chapter. (6) The City Engineer shall maintain the records of all appeal actions and report any variances to the Federal Insurance Administration upon request. (b) Conditions for Variances (1) Variances may be issued for the reconstruction, rehabilitation, or restoration of structures listed on the National Register of Historic Places, the State Inventory of Historic Places, or the City of San Luis Obispo Historical $ Architectural Element of the General Plan, without regard to the procedures set forth in the remainder of this section. (2) Variances shall not be issued within any designated floodway if any increase in flood levels during the base flood discharge would result. (3) Variances shall only be issued upon a determination that the variances is the minimum necessary, considering the flood hazard to afford relief. (4) Variances shall only be issued upon: (aa) A showing of good and sufficient cause; (bb) A determination that failure to grant the variance would result in exceptional hardship to the applicant; and • SECTION 9815. SPECIAL STANDARDS. In all areas of special flood hazards where base flood elevation data has been provided as set forth in Section 9804, BASIS FOR ESTABLISHING THE AREAS OF SPECIAL FLOOD HAZARD, or in Section 9812(b), Use of Other Base Flood Data, the following standards are required: (a) Residential Construction. New construction and substantial improve- ment of any residential structure shall have the lowest floor, including basement, elevated to at least one foot (11) above base elevation. (b) Nonresidential Construction. New construction and substantial improvement of any commercial, industrial or other nonresidential structure shall either have the lowest floor, including basement, elevated to one foot (11) above the level of the base flood elevation; or together with attendant utility and sanitary facilities, shall: (1) Be floodproofed to one foot (11) above the base flood level so that the structure,including utilities and plumbing facilities, is watertight with walls substantially impermeable to the pressure of water; (2) Have structural components capable of resisting hydrostatic 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 certification shall be provided to the City Engineer. (c) Mobile Homes. _ (1) Mobile homes shall be anchored in accordance with Section 9814 (a) (2) (2) For new mobile home parks and mobile home subdivisions; for expansions to existing mobile home parks and mobile home sub- divisions; for existing mobile home parks and mobile home sub - divisions;where the repair, reconstruction or improvement of the streets, utilities, and pads equals or exceeds 50 percent of value of the streets, utilities and pads before the repair, reconstruction or improvement has commenced; it shall be required that: (aa) Stands or lots are elevated on compacted fill or on pilings so that the lowest flood of the mobile home will be at least one foot (11) above the base flood level; (bb) Adequate surface drainage and access for a hauler are provided; and (cc) In the instance of elevation on pilings, that: - -lots are large enough..to, permit steps; -- piling:;foundations are placed in stable soil no more than ten feet apart; and -- reinforcement is provided for pilings more than six feet above the ground level. (3) No mobile home shall be placed in a floodway, except in an existing mobile home park or an existing mobile home sub- division. (cc) A determination that the granting of a variance will not result in increased flood heights, additional threats to public safety, extraordinary public expense, create nuisances, cause fraud on or victimization of the public as identified in subsection (a).(1) through (a) (4) above, cause any environmental impact that cannot be mitigated, or conflict with existing local laws or ordinances. (5) Any applicant to whom a variance is granted shall be given written, notice that the structure will be permitted to be built with a lowest floor elevation below the base flood elevation and that the cost of flood insurance will be commensurate with the increased risk resulting from the reduced lowest floor elevation. SECTION 9814. GENERAL STANDARDS FOR FLOOD HAZARD REDUCTION. In all areas of special flood hazards the following standards are required: (a) Anchoring. (1) All new construction, substantial improvements and storage of materials shall be anchored to prevent flotation, collapse, or lateral movement. Materials capable of displacement due to flooding (including dissolvables) may not be stored within A Zones unless the site is floodproofed or finished grade is raised to eliminate flood hazards. (2) The anchoring of mobile homes shall be goverened by the State of California Administrative Code, Title 25, Chapter 5. (b) Construction Materials and Methods. (1) All new construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage. (2) All new construction and substantial improvements shall be constructed using methods and practices that minimize flood damage. (c) Utilities. (1) All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of flood waters into the system; (2) New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of flood waters into the systems and discharge from the system into flood waters; and (3) On -site waste disposal systems shall be located to avoid impair- ment to them or contamination from them during flooding. (d) Subdivision Proposals. I (1) All subdivision proposals shall be consistent with the need to I minimize flood damage; (2) All subdivision proposals shall have public utilities and facil- ities such as sewer, gas, electrical and water systems located and constructed to minimize flood damage; (3) All subdivision proposals shall have adequate drainage provided to reduce exposure to flood damage; and (4) Base flood elevation data shall be provided for subdivision proposals and other proposed development which contain.at least fifty (50) lots or five (5) acres, whichever is less. SECTION 9816. FLOODWAYS. Located within areas of special flood hazards established in Sections 9805 are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of flood waters which carry debris, potential projectiles, and erosion potential, the following provisions apply: (a) Encroachments, including fill, new construction, substantial improve- ments, and other development are prohibited unless certification by a regis- tered professional engineer is provided demonstrating -that encroachments increase in flood_ levels during the shall not result in any occurrence of the base flood discharge. - - - - -- (b) If subsection (a), above, is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of Section 9814, GENERAL PROVISIONS FOR FLOOD HAZARD REDUCTION. (c) The placement of any mobile homes, except in an existing mobile home park or existing mobile home subdivision, is prohibited.