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Ordinance 1983-002 Providing the Flood Damage PreventionORDINANCE NO. ~_ - 1983 AN ORDINANCE OF THE VILLAGE OF NORTH PALM BEACH, FLORIDA, PROVIDING FOR FLOOD DAMAGE PREVENTION WITHIN THE CORPORATE LIMITS OF THE VILLAGE OF NORTH PALM BEACH. BE IT ORDAINED BY THE VILLAGF. COUNCIL OF NORTH PALM ' BEACH, FLORIDA: Section 1. STATUTORY AUTHORIZATION. The Legislature of the State of Florida has, in Chapter 163, Florida Statutes, delegated the responsibility to local governmental units to adopt regulations designed to promote the public health, safety and general welfare of its citizenry. Section 2. FINDINGS OF FACT. (1) The flood hazard areas of the Village of North Palm Beach are subject to periodic inundation which results in loss of life and property, health and safety hazards, disruption 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 caused 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 flood-proofed or elevated, or otherwise unprotected from flood damage, contribute, also to the flood loss. Section 3. STATEMENT OF PURPOSE AND OBJECTIVES. The purpose and objectives of this Ordinance are 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:. (1) To protect human .life and healthf (2) To minimize expenditure of public money for costly flood control projects? (3) To minimize the heed,~for rescue and relief efforts associated with flooding and generally undertaken at the expense of the general publics (4) To minimize prolonged business interruptionst (5) 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) (6) 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 areast (7) To insure that potential buyers are notified that property is in an area of special flood hazard; and, (B) To insure that those who occupy the areas of special flood hazard assume responsibility for ' their actions. Section 4. METHODS OF REDUCING FLOOD LOSSES. In order to accomplish its purpose and objectives, this Ordinance includes methods and provisions for: (1) 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 i'n flood heights or velocities; (2) Requiring that uses vulnerable to floods, including facilities which serve such uses, be protected against flood damage at the time of initial construction) ' (3) Controlling the alteration of natural flood plains, stream channels and natural protective barriers, which help accommodate or channel flood waters; 2 (4) Controlling filling, grading, dredging and other development which may increase flood damage; and (5) Preventing or regulating the construction of flood barriers which will unnaturally divert flood waters or which may increase flood hazards ' in other areas. Section 5. DEFINITIONS. Unless specifically defined below, words or phrases used in this Ordinance shall be interpreted so as to give them the meaning they have in common usage and to give this Ordinance its most reasonable application. APPEAL - A request for a review of the Flood Damage Control Administrator's interpretation of any provision of this Ordinance or a request for a variance. AREA OF SHALLOW FLOODING - A designated AO, AH or VO Zone on a community's Flood Insurance Rate Map, (FIRM), with a one percent or greater annual chance of annual flooding. 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. 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. Designated as Zones A, AO, AH, Al-99, VO or V1-30 on a community's FIRM. BASE FLOOD - The flood having a one percent chance of being equalled or exceeded in any given year. ' BASE FLOOD ELEVATION - The crest elevation in relation to mean-sea-level (using National Geodetic Vertical Datum) expected to be reached during a flood which encompasses the regulatory flood plain: 3 T BREAKAWAY WALLS - Aesthetic Lattice Walls or Screening using approved materials, which are not part of the structural support of the building and which are designed as to breakaway, under abnormally high tides or wave action, without damage to the structural ' integrity of the building on which they are used. COASTAL HIGH HAZARD AREA - An area within the regulatory flood plain which is subject to high velocity waters, including hurricane wave wash. The area is designated on a FIRM as Zone V1-30. DEVELOPMENT - Any man-made change to improved or unimproved real estate, incuding, 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. FLOOD OR FLOODING - A general and temporary condition of partial or complete inundation of normally dry land areas from: (1) The overflow of inland or tidal waterer and/or , (2) The unusual and rapid accumulation or runoff of surface waters from any source. FLOODBOUNDARY AND FLOODWAY MAP - The official map on which the Federal Emergency Management Agency has delineated both the Flood Boundaries and the Regulatory Floodway. ' FLOOD DAMAGE CONTROL ADMINISTRATOR - the officer of the Village of North Palm- Beach responsible for the delegation of responsibilities for the individual tasks contained herein. 4 FLOOD ELEVATION DETERMINATION -~A determination by the Federal Emergency Management Agency of the water surface elevations of the bas@ flood, that ie, the flood level that has a one percent or greater chance of occurrence in any given year. ' FLOOD INSURANCE RATE MAP (FIRM) - An official map of a community, on which the Federal Emergency Management Agency has delineated both the special flood hazar8 areas and the risk premium zones applicable to the community. FLOOD INSURANCE STUDY - The official report provided by the Federal Emergency Management Agency. The report contains flood profiles and water surface elevation of the base flood. It may include the Flood Boundary - Floodway Map. FLOOD PLAIN - Land which will be inundated by floods known to have occurred or reasonably characteristic of what can be expected to occur from the overflow of inland or tidal waters and the accumulation of runoff of surface waters from rainfall. FLOOD PLAIN MANAGEMENT REGULATIONS; - Any zoning ordinances, subdivision regulations, building codes, health regulations, special .purpose ordinances (such as a flood plain management ordinance, grading ordinance and erosion control ordinance), ane other applications of police powers. The term describes such state or local regulations, in any combination thereof, which provide standards for the purpose of flood damage prevention and reduction. FLOOD-PROOFING - Structural changes or adjustments incorporated in the design or construction of a building so as to make the building water-tight with 5 walls substantially impermeable to the passage of water and with structural components having the capacity of resisting hydrostatic and hydrodynamic loads and effects of buoyance for the reduction or elimination of flood damages. FLOODWAY - See REGULATORY FLOODWAY. FLOODWAY ENCROACHMENT LINE - The line marking the limits of floodway maps on Federal, State an8 local flood plain maps. FLOOR - The top surface of an enclosed area in a building (including basement), i.e., top of slab in concrete slab construction or top of wood flooring in wood frame construction. The term does not include the floor of a garage used solely for parking vehicles. HIGHEST ADJACENT GRADE - The highest natural elevation of the ground surface prior to construction next to the proposed walls of a structure. MANGROVE STAND - An assemblage of mangrove trees which are mostly low trees noted for a copious development of interlacing adventitious roots above the ground and which contain one or more of the following species: black mangrove (Avicennia Nitida)i red mangrove (Rhiziphora Mangel)= white mangrove (Languncularia Racemosa)J and buttonwood (Conocarpus Erects). MSL - The average height of the sea for all stages of the tide. it is used as a reference for establishing ' varying elevations within the flood plain. For purposes of this Ordinance, the term is synonymous with National Geodetic Vertical Datum (NGVD). 6 NATIONAL GEODETIC VERTICAL DATUM - (NGVD) as corrected in 1929 is a vertical control used as a reference for establishing varying elevations within the flood plain. NEW CONSTRUCTION - Structures for which the "start of ' construction" commenced on or after the effective date of this Ordinance. REGULATORY FLOOD - For purposes of this Ordinance, a flood event having a one percent chance of occurring in any given year, although the flood may occur in any year, i.e., the 100-year flood. REGULATORY FLOOD ELEVATION - The crest elevation in relation to mean sea level expected to be reached by the regulatory flood at any given point in an area of special flood hazard. REGULATORY FLOODWAY - The channel of a~river or other ' water course and the adjacent land areas that must be reserved in order to discharge the velocity waters of the regulatory flood. SAND DUNES - Naturally occurring accumulations of sand in ridges or mounds landward of the beach. START OF CONSTRUCTION - The first placement of permanent construction of a structure 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 excavation for a basement,, footings, piers or foundations or the erection of temporary format nor does it include the installation on the property of accessory buildings, such as garages or sheds not occupied as dwelling 7 units or not as part of the main structure. For, a structure 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. ' STRUCTURE - A walled and roofed building., that is principally above ground and affixed to a permanent site. The term includes a building while in the course of construction, alteration or repair, but does not include building materials or supplies intended for use in construction, alteration or repair, unless such materials or supplies are within an enclosed building on the premises. The words "building" and "structure" shall have the same meaning for the purposes of this Ordinance. 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: (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 purpose of this definition, "substantial improvement" is considered to occur when the first alteration of any wall, ceiling, flood or other structural part of the building commences, whether or not that alteration affects the external dimensions of the structure. The term does 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 8 (2) any alteration of a ~tructu'Ye listed on the National Register "of Historic Places or a State Inventory of Historic Places. VARIANCE - A grant of relief from the requirements of this Ordinance which permits construction in a manner ' that would otherwise be prohibited by t-~is Ordinance. WATER SURFACE ELEVATION - The projected. heights in relation to Mean Sea Level reached by floods of various magnitudes and frequencies in the flood plain of coastal or riverine areas. Section 6. LANDS TO WHICH THIS ORDINANCE APPLIES. This Ordinance shall apply to all areas of special flood hazards within the jurisdiction of the Village of North Palm Beach. Section 7. BASIS FOR ESTABLISHING THE AREAS OF SPECIAL__FLOOD_ HAZARD. The areas of special flood hazard ' identified by the Federal Emergency Management Agency in a scientific and engineering report entitled, "The Flood Insurance Study for the Village of North Palm Beach," dated April 4, 1982, with accompanying Flood Insurance Rate Map, are hereby adopted by reference and declared to be a part of this Ordinance. The Flood Insurance Study is on file at the Office of the Village Clerk, North Palm Beach Village Hall, U. S. Highway 1, North Palm Beach, Florida. Section 8. PENALTIES FOR NONCOMPLIANCE. No structure or land shall hereafter be constructed, located, extended, converted or altered without full compliance with the terms of this Ordinance. Failure to comply with any of its requirements (including violations of conditions and safeguards established in connection with grants of variance or special exceptions) shall constitute a misdemeanor. Any person who violates this Ordinance or fails to comply with any of its requirements shall upon conviction thereof be fined not more .than $500.00 or 9 imprisoned for not more than sixty (60) days, or both, for each violation, and in addition shall pay all costs and expenses involved in the case. Each, day such violation continues shall be considered a separate offense. Nothing herein contained shall prevent the Village of North Palm Beach from taking such other lawful action as is necessary to prevent or remedy any violation. Section 9. ABROGATION AND GREATER .RESTRICTIONS. This Ordinance is not intended to .repeal, abrogate or impair any existing easements, covenants or deed restrictions. However, where this ,Ordinance and other ordinance, easement, covenant or deed restriction conflict or overlap, whichever imposes the more stringent restrictions shall prevail. Section 10. INTERPRETATION. In the interpretation and application of this Ordinance, all provisions shall be: (1) Considered as minimum requirements; (2) Liberally construed in :favor of the governing body; and (3) Deemed neither to limit nor repeal any other powers granted under State Statutes. Section 11. WARNING REGARDING "AREA OF SPECIAL FLOOD HAZARD" DESIGNATIONS. The degree of flood protection required by this ordinance 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 Ordinance does. not imply that land outside the area of special flood hazards or uses permitted within such areas will be free from flooding or flood damages. Section 12. DESIGNATION OF THE FLOOD DAMAGE CONTROL ADMINISTRATOR. The Village Building Official is hereby appointed the Flood Damage Control Administrator to administer and implement this Ordinance. (The Village Building Official may delegate the responsibilities for the individual tasks contained herein.) 10 Section 13. 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 7. Apjplication for a Development Permit shall be made on forms furnished by the Flood Damage ' Control Administrator 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: (1) Elevation in relation to mean sea level of the proposed lowest floor (including basement) of all structures: (2) Elevation in relation of mean sea level to which any structure will be floodproofed; (3) Certification by a registered professional engineer or architect that the floodproofing methods for any nonresidential structure meet the floodproofing criteria in Section 17B; and, (4) Description of the extent to which any watercourse will be altered or relocated as a result of proposed development. (5) Provide a flood elevation of floodproofing certification after the lowest floor is completed, or in instances where the structure is subject to the regulations applicable to Coastal High Hazard Areas, after placement of the horizontal structural members of the lowest floor. within twenty-one calendar days of establishment of the lowest floor elevation, or floodproofing by whatever construction means, or .upon placement of the horizontal structural members of the lowest floor, whichever is applicable; it shall be the duty of the permit holder to submit to the Village 11 Building Official a certification of the elevation of the lowest floor, floodproofed elevation, or the elevation of the lowest portion of the horizontal structural members of the lowest floor, whichever is applicable, as built, in relation to mean sea level. Said certification shall be prepared by or under the direct supervision of a registered land surveyor or professional engineer and certified by same. When floodproofing is utilized for a particular building, said certification shall be prepared by or under the direct supervision of a professional engineer or architect and certified by same. Any work done within the twenty-one calendar day period and prior to submission of the certification shall be at the permit holder's risk. The Village Building Official shall review the Flood Elevation Survey data submitted. Deficiencies detected by such review shall be corrected by the permit holder immediately and prior to further progressive work being permitted to proceed. Failure to submit the survey or failure to make said corrections required hereby, shall be cause to issue a stop-work order for the project. Section 14. DUTIES AND RESPONSIBILITIES OF THE FLOOD DAMAGE CONTROL ADMINISTRATOR. Duties of the Flood Damage Control Administrator shall include, but not be limited to: A. Permit Review. (1) Review all development permits to determine that the permit requirements of this Ordinance have been satisfied. (2) Review all development permits to determine that all necessary permits have been obtained from those Federal, State or local governmental agencies from which prior approval is required. 12 (3) Review all development permits in the coastal high hazard area of the area of special flood.-hazard to determine if the proposed development alters mangrove stands or sand dunes so as to increase potential flood damage. (4) Review plans for walls to be used to enclose space below the base flood level in accordance with Section 19B(4). B. Use of Other Base Flood Data. When base flood elevation data has not been provided in accordance with Section 7, BASIS FOR ESTABLISHING THF, AREAS OF SPECIAL FLOOD HAZARD, the Flood Damage Control Administrator shall obtain, review and reasonably utilize any. base flood elevation data available from a Federal, State or other source (U. S. . Army Corps of Engineers, U. S. Geological Survey, U. S. Soil Conservation Service, State water Management Districts), in order to administer Sections 17A, SPECIFIC STANDARDS, Residential Construction, and 178, SPECIFIC STANDARDS, ~,, Non-residential Construction. C. Information to be Obtained and Maintained. (1) obtain and record the actual elevation (in relation to .mean sea level) of the lowest habitable floor (including basement) of all new or substantially improved structures, and whether or not the structure contains a basement. (2) For all new and substantially improved floodproofed structures: ' (i) verify and record the actual elevation (in relation to mean sea level); and 13 (ii) maintain the floodproofing certifications required in Section 13(3) . (3) in coastal high hazard areas, certification shall be obtained from a registered ' professional engineer or architect that the provisions of Section 19B(1) and 19B(2)(i) and (ii) are met. (4) Maintain for public inspection all records pertaining to the provisions of this Ordinance. D. Alteration of Watercourses. (1) Notify adjacent communities and the Florida Department of Veteran and Community Affairs 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 15. Section 15. VARIANCE PROCEDURE. A. Appeals Board. (1) The Village Contractors' Board as established by the Village of North Palm 14 Beach shall hear and• decide appeals and requests for variance from the requirements of this Ordinance. (2) The Village Contractors' Board shall hear and decide appeals when it is alleged there is an error in any requirement, decision or determination made by the Flood Damage Control Administrator in the enforcement or administration of this Ordinance. (3) Those aggrieved by the decision of the Village Contractors' Board, or any taxpayer, may appeal such decision to the Circuit Court. (4) In passing upon such applications, the Village Contractors' Board shall consider all technical evaluations, all relevant factors, standards specified in other sections of this Ordinance, and, (i) the danger that materials may be swept onto other lands to the injury of others; (11) the danger to life and property due to flooding or erosion damages (iii) the susceptibility of the proposed facility and its contents to flood damage and the effect to such damage on the individual owner; (iv) the importance of the services provided by the proposed facility to the community; (v) the necessity to the facility of a waterfront location, where applicable; (vi) the computability of the proposed use with. existing and anticipated developments 15 (vii) the relationship of the proposed use to the comprehensive plan and flood plain management program of that area? (vi) the availability of alternative locations not subject to flooding or erosion damage for the proposed use; (ix) the safet f y o access to the property in times of flood for ordinary and emergency vehicles; (x) 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, (xi) 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. (5) Upon consideration of the factors of Section 15A(4) and the purpose of this Ordinance, the Village Contractors' Board may attach such conditions to the granting of variances as it deems necessary to further the purposes of this Ordinance. (6) The Flood Damage Control Administrator shall maintain the records of all appeal actions, including technical information, and report any variances to the Federal Insurance Administrator upon request. (7) Variances shall not be issued within any regulatory floodway if any increase in flood levels would result during a base flood discharge. 16 public expense ,.create nuisances, cause fraud on or victimization of the public, or conflict with the local government comprehensive plan or with other existing local laws or ' ordinances. (5) Any applicant to whom a variance is granted shall be given written notice specifying the difference between the base flood elevation and the elevation to which the structure is to be built ane stating that the cost of flood insurance will be commensurate with the increased risk resulting from the reduced lowest floor elevation. Section 16. GENERAL STANDARDS. In all areas of special flood hazards, the following standards are required: A. Anchoring.• All new construction and substantial improvements shall be anchored to prevent flotation, collapse or lateral movement of the structure. 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 systems 18 B. Conditions for Variances. (1) Variances may be issued for new construction and substantial improvements to be erected on a lot one-half acre or less in size contiguous to and surrounded by lots with ' existing structures constructed below the base flood level rovidin items (i-xi) i , p g n Section 15A(4) have been fully considered. As the lot size increases beyond the one-half acre, the technical justification required for issuing the variance increases. (2) Variances may- be issued for the reconstruction, rehabilitation or restoration of structures listed on the National Register of Historic Places or the State Inventory of Historic Places, without regard to the procedures set forth in the remainder of this Section. (3) Variances shall only be .issued upon a determination that the variance is the minimum necessary, considering. the flood hazard, to afford relief. (4) Variances shall only be issuee upon: (i) a showing of good and sufficient causer (ii) a determination that failure to grant the variance would result in exceptional hardship to the applicants and, (iii) a determination that the granting of a variance will not result in increased flood heights, additional threats to public safety, extraordinary 17 (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 systems into flood waters; and, (3) On-site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding. D. Subdivision Proposals. (1) All subdivision proposals shall be consistent with the needs to minimize flood damage= (2) All subdivision proposals shall have public utilities and facilities 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 damages and, (4) Base flood elevation data shall be provided for subdivision proposals and other proposed development which contain at least 50 lots or 5 acres .(whichever is less). Section 17. SPECIFIC STANDARDS. In all areas of special flood hazards (Zones A, Al-30, AH) where base flood elevation data have been provided as set forth in Section 7: BASIS FOR ESTAALISHING AREAS OF SPECIAL FLOOD HAZARD, or in Section 14B, USE OF BASE FLOOD DATA,. the following standards are required: A. Residential Construction. ' New construction and substantial improvement of any residential structure shall have the lowest floor, including basement, elevated to or above base flood elevation. 19 B. Nonresidential Construction. ~~ New construction. and substantial improvement of any commercial, industrial or other non-residential structure shall either have the lowest floor, including basement, elevated to the level of the base ' flood elevation; or, together with attendant utility and sanitary .facilities, shall: (1) be floodproofed to a minimum of one foot above the base flood elevation and the structure below the flood elevation is watertight with walls substantially impermeable to the passage of waters (2) have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyance; and (3) be certified by a registered professional engineer or architect that the standards of ' this subsection are satisfied. Such certifications shall' be provided to the official set forth forth in Section 14C(2). Section 18. REGULATORY FLOODWAYS. When floodways are designated within areas of special flood hazard, additional criteria will be met. 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 shall apply: (1) Prohibit encroachments, including fill, new construction, substantial improvements and other developments, unless certification by a professional registered engineer or ' architect is provided demonstrating that encroachments shall not result in any increase in flood levels during occurrence of the base flood discharge. 20 (2) If Section 18(1) is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of Sections 16 and 17. Section 19. COASTAL HIGH HAZARD AREAS. Coastal high ' hazard areas (V Zones) are located within the areas of special flood hazard established in Section 7. These areas have special flood hazards associated with high velocity waters from tidal surges and hurricane wave wash) therefore, the following provisions shall apply: A. Location of Structures. All buildings or structures shall be located landward of the reach of the mean high tide. B. Construction Methods. (1) Elevation. All buildings or structures shall be elevated so that the lowest portion of the structural members ' of the lowest floor is located no lower than the base flood elevation level, with all space below the lowest floor's supporting member open so as not to impede the flow of water, except for breakaway walls as provided for in Section 19B(4). (2) Structural Support. (i) All buildings or structures shall be securely anchored on pilings or columns. (ii) Pilings or columns used as structural support shall be designed and anchored so as to withstand all applied loads of the base flood flow. (iii) There shall be no fill used for structural support. (3) Certification. 21 Compliance with the provisions of Sections 19B(1) and 19B(2)(i) and (11) shall be certified to by a registered professional engineer or architect. (4)' Space Below the Lowest Floor. (i) Any alteration, repair, reconstruction or improvement to a structure started after the ' enactment of this Ordinance shall not enclose the space below the lowest floor :unless breakaway walls of lattice work or decorative screening are used as provided for in this Section. (ii) Open wood construction lattice breakaway walls or decorative screening shall be allowed below the base flood elevation provided they are not a part of the structural ,support of the building and are designed so es to breakaway, under abnormally high tides or wave action, without damage to the structural integrity of the building on which-they are to be used. ' (iii) If breakaway walls are utilized, such enclosed space shall not be used for human habitation. (iv) Prior to construction, plans for any structure that will have breakaway walls -must be submitted to the Flood Damage Control Administrator. Section 20. SAND DUNES AND MANGROVE STANDS. There shall be no alteration of sand dunes or mangrove stands which would increase potential flood damage. Section 21. .STANDARDS FOR AREAS OF SHALLOW FLOODING. Located within the areas of special flood hazard established in ' Section 7, are areas designated as shallow flooding (AO Zones). These areas have special flood hazards associated with base flood depths of one to three feet where a clearly defined channel does not exist and where the path of flooding is unpredictable and indeterminate) therefore, the following provisions apply: 22 A. All new construction and .substantial improvements of residential structures shall have the lowest floor, including basement, elevated to the depth number ' specified in the Flood Insurance Rate Map, in feet, above the highest adjacent grade. if no depth number ' is specified, the lowest floor, including basements, shall be elevated at least t (2 f t b wo ) ee a ove the highest adjacent grade. B. All new construction an8 substantial improvements of non-residential structures shall: (1) have the lowest floor, including basement, elevated to the depth number specified on the Flood Insurance Rate Map, in feet, above the highest adjacent grade. If no depth number is specified, the lowest floor, including basement, shall be elevated at least two feet above the highest adjacent grade, or ' (2) together with attendant utility and sanitary facilities be completely floodproofed a minimum of one foot, plus the depth number specified on the FIRM, .in feet, above the highest adjacent grade, or if no depth number is specified, floodproofing must be a minimum of three feet above the highest adjacent grade, so that any space below that level is watertight with walls substantially impermeable to the passage of water and with structural components having, the capability of resisting hydrostatic end hydrodynamic ' loads and effects of buoyancy. C. Adequate drainage paths shall be provided around structures on slopes, to guide floodwaters around and away from proposed structures. 23 Section 22. STANDARDS FOR SMALL STREAMS. Located within the areas of special flood hazard estab~.ished in Section 7 where small streams exist, but where no base flood data has been provided or where no floodways have been provided, the following provisions apply: (1) No encroachments, including fill material or ' structures, shall be located within a distance of the stream bank. equal to five (5) times the, width of the stream at the top of bank or twenty feet on each side from top of bank, whichever is greater, unless certification by a registered professional engineer is provided demonstrating that such encroachments shall not result in any increase in flood levels during the .occurrence of the base flood discharge. (2) New construction or substantial improvements of structures shall be elevated or ' floodproofed in accordance with elevations established in accordance with Section 17. Section 23. SEVERABILITY. It is declared to be the intent of the Village of North Palm Beach that if any section, subsection, sentence, clause, phrase or provision of this ordinance is held invalid or .unconstitutional, such invalidation or unconstitutionality shall not be construed as to render invalid or unconstitutional the remaining provisions of this Ordinance. Section 24. EFFECTIVE DATE. This Ordinance shall take effect immediately upon passage. PLACED ON FIRST READING THIS 27 DAY OF Jl~)UA[ZX , 1983. PLACED ON SECOND, FINAL READING AND PASSED THIS 10 DAY OF FEBRUARY , 1983. (Vi.1l.age Seal) ATTEST:. ~~~ ~~ ~ ~ ~ Village Clerk ~ 0049G/de 24