Loading...
HomeMy WebLinkAboutORD 3158' • • ORIGH\JAL ORDINANCE NO. _ 3158·-- ORDINANCE OF 'rHE COUNCIL OF THE CITY O~i' PALO ALTO AMEr.t"DING TITLE 16 OF THE P.A!.O ALTO MUNICIPAL CODE BY ADDING CHAPTER 16.52 THERETO. REPEALING SECTION 16.04.185, AND AMENDING CHAPTER 21.20 OF THE PALO ALTO MUNICIPAL CODE BY ADDING SEC'riON 21.20.310 THERETO, REGARDING FLOOD HAZARD REGULATIONS WHEREAS 1 the National Flood Insurance Act of 1968, as amended, and federal regulations adopted thereunder by the Flood Insurance Administration (FIA) require in connection with the adoption of a Flood Insurance Rate Map (FIRM) by FIA that local jur~sdictions for which those maps sre adopted shall adopt special building regulations for .flood hazard u·eas within the jurisdictl.on; and 1 WHEREAS, the FIA had adopted or will shortly adopt a FIRM for the City of Palo Alto. NOW, 1'HEREP'ORE, the Counc:i..l of the City of Palo Alto does hereby ORDAIN a.s f'ollows ~ SECTION 1. Chaoter 16.52 is hereby added to Title 16 of the Palo Alto Municipal Code to read as set forth i.n Exhibit "A" attached hereto and incorporated herein by this reference. SECTION 2. Section 21.20.310 is hereby added to Chapter 21.20 of the Palo~ "Kfto Municipal Code as adopted by Ordinance No • .3157 to -..--.·' !'€ad as sat forth .in Exhibit "B" at tac.hed hereto and inc.orporated herein by this reference. SECTION 3. Section 16.04.185 of the Palo Alto Municipal Code is hereby deleted. SECTION 4. The Council hereby finds that the adoption of this ordinance will' not have any signJficant adverse impact on the environment. SEC'fiON 5. This ordinance Elhall become effective upon the commence­ ment of' the thirty-first day following the date of its adoption. INTRODUCED: August 20, 1979 PASSED: September 11, 1979 AYES: Brenner, Eyerly, Fazzino, Fletcher~ Henderson, Levy~ Renzel, Sher NOES: None ABSTENTIONS: None ABSENT: Witherspoon APPROVED: • . ' • APPROVED: - 2 ... • 16.52.010 that: • CHAPTER 16.52 }i'LOOD HAZARD REGULA'l'IONS • Findings. The Council of the City of Palo Alto finds (a) The National Flood Insurance Act of 1968, as amended, and federal regulations promulgated thereunder, require the City to adopt certain flood hazard regulations in conformance with standards established by the Flood Insurance Administration; (b) The flood hazard areas of the City are subject to periodic inundation which may result in loss of life and property, impose health and safety hazards, disruption of commerce and governmental services, ext:caordinary publ:ic expenditures for flood protection a:o.d reU.ef, and impairment of the tax base, all of which adversely affect the public health, safety 1 and general welfare; and (c) These flood losses are often 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 floodproofed, elevated or otherwise protected from flood cl.amag~) also contribute to the flood loss. 16.52.020 Purpose. This Chapter is adopted in order to nomply with the National Flood Insurance Act of 1968, as amended, and federal regulations adopted thereunder for the purpose of promoting the public health, safety, and general welfare, and to n1inimize public and private losses due to flood conditions in speci.fic areas by provisions designed: (a) To protect human life and health; (b) To minimize the need for costly flood control projects, and to supplement the effectiveness of such projects; (c) To minimize the need for rescue and relief efforts associ&~ed with flooding and generally undertaken at the expense of the general v '"Jl ic; (d) To minimize prolonged business interruptions; (e) To minimize damage to public facilities and utilities sucb as water and gas mains, electric 1 telephone and sewer lines, streets and bridges loc&ted in areas of special flood hazard; (f) To help maintain a stable ta~ base by providing for the second use and development of areas of special flood hazard so a~ to minimize future flood blight areas; (g) To insure that potential buyers are notified that property is in an area of special flood hazard. Section 16.52.030 Goals. In order to a.ccomplish 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 velocitie~:;; • (b) Requiring tbat uses vulnerable to floods, including facilities which seTve 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 accom­ modate or channel flood waters; (d) Controlling filling, gradingt dredging, and other development which may increase flood damage; and (e) Preventing or regulating the construction of flood barriers which ~ill unnaturally divert flood waters or which may in­ crease flood hazards in other areas. Section 16.52.040 Definitions. The definitions contained hereafter shall govern the interpretation of the terms defined for the purposes of this chapter, except where the context clearly requires otherwise. Words used in this chapter and not defined herein sh~ll be interpreted so as to give them the meaning they have in co.mmon usage a.nd to gi.ve this chapter iLs most reasonable applications. (a.) (b) (c) (d) (e) (f) {,g) "Area of _shallow flo.2.~.t!!lin means a designated AO Zone on the Flood Insurance Rate Map (FIRM). The ba.se flood depths range! from one to th:ree feet; a. clea.rly defined channel does not c~xist; the patil of flooding is unpredictable and indeterminate; and, velocity flow may be evident. HArea of specia.}. flood hazardn means the land in the flood plain within a community subject to a one percent or greater chance of flooding in any given year. ''Base flood" means the flood having a one percent chance of being equalled or exceeded in any given year. 11 Deve1opmentl 1 means any man-ma.de change to improved or unimproved real estate, including, but not limited to buildings or other. structuTes, mining, dredging, filling, grading, paving, excava­ tion or drilling operations located within the area of special flood hazard. "E.xistin mobile home ar.k or mobile home subdivision" means a parcel or contiguous parcels of land-divided into two or cnore mobile home lots for rent or sale for which the constrr•-1- tion of facilities for servicing the lot on which the mobile home :f_s to be affixed (including, at a· m·inimum, 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 ordinance. "E a.t."1sion to an existin · m~q,bile home ,Eark...£!:_~le home su ivis on means t e prepkratioti of adaitional sites by the construction of facilities for servicing the lots on which the mobile homes a:;.·e to be affixed (including the installation of utilities~ either final site grading or pouring of concrete pads, or the construction of streets). nJnood 11 or~lood.iE.i,u means a general and temporary cond.i tion of partial or coroplete inundation of normally dry land areas from: - 2 - (h) ( i ) / i ) \.,_, (1) (m) (n) • (1) The overflow of inland or tidal water!:l and/or (2i The unusual and r~pid aceumulation or ru!ioff of surface waters from any source, .:J':lood Insurance Rate Map_11 (,f_IRM) means the offici a 1 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. "Flood ~-urance Stu.dz 11 means the official report provj.ded by the Federal Insurance Administration tha.t includes flood profiles, the Flood Boundary-Floodway Map, and the water sur­ face elevation of the base flood. "Habitable floor!! means any floor usa.ble for living pu!'poses, which includt:s '.vorking~ sleE~ping} eating, cooking or recre£~.tion, G!' a combination thereof, A floor used only for storage pur­ po~;cs i.s not a "habitabJe floor.'' "Mobile home" means a strv.ctu.re that is transportable in one 'or-mml s8ctj_ons 1 built on a permanent chassis, and desi.gned to be used with cr without a permanent foundation when con­ nected to the required utilities. It does not include recrea­ tional vehicle~ or travel trailers. ''New construe tion 1 ' means structures for which the 11 start of C::cm.structT{m'1 'CO'!Tlmenced on ot· after the effectJ.ve date of this ehapter. ' 1New lilobile hom~ pa!:k c~_!,!l.~}?_!)_~~~~bdivisia:1 11 means a parcel (or contiguous parcels) :.t· land dividect into two or more mobile horne lots for rent or sale for which the construc­ tion of facilities for servicing the lot (including, at a minimum~ the installation of utilities 1 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 ordJnance. ''Start of construction 11 means the first placement of permanent construetion 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 excavationo Permanent construction does not include land preparation, such as clearing, grading, and fillingJ nor does it include the installation of streets and/ or walkways; nor does it include excavation for a basement, footings, piers or foundations or the erection of temporary forms; nor does it include the installation on the property of accessory buildings~ such as garages or sheds not occupied as dwelling uni'ts: or not as part of the ma:i.n structure. For s. structure (other than a mobile home) without a basement or poured footings, the 11 start of construction" includes the f}.rst permanent framing or assembly of a structure or a.ny part thereof on its piling or foundation. For mobile homes not within a mobile home park or mobile home subdivision.: 11 Start of -construction 11 means the affixing of the mobile home to its permanent site. For mobile homes within mobile horne parks or mob1le home subdivisions, 11 start of construction'' is the data on which the construction of facilities for ser­ vicing the site on which the mobile home is to be affixed - 3 - (o) (p) (q) ----·---·-·----·-... ·--··-···----------------. e e (including, at a minimum, tht~ construction of strec~ts, either !'ina l sj tc grading Ol' the pour in(.; of concrete pad~, and in­ st<l,}l3.t.ion of utilitif':->) is complt:!ted. "St;ouctun'11 mc·:1ns n walh•d and J'oofcd building or mobi lc home that is prin<.:-ipaJly above ground, nsubstanti.nl. impro\·c:n·t--.nt" means any rE>pn.ir, reconstruction, or iinprOV\:Jril~!)( of a StJ.'UCtUrc, the C-OSt of Which equals Or exceeds bO percent of the market value of thrJ structure either: (l) Before the improvement or repnjr is started, or (2) If thG structure bas been damaged and is being restorod 1 bcJu!·c tlw damage oc.ct\r red. For the purposN> of this def.in:tt.ion "f;ubstantial improvement,. is eonsidered to oe{'Ul' ~'.ben the first altc~·ation of any wall, ceiling, flool', or r:::,ther !;tructm·;-;J_ part of the bui ld.i ng commences, wlwthc:r or· not that alt0ration ::lffcct~; the e-xternal dimen-· ~'ion f; of t-ile ~;t -~·-ue t u l't!. TlH~ t~rm doc'; not, hov-l"."Oi', include cjtber: ( l) :\ny p:\'()jC't~t for in:prcvcr.1ent of a structure to c.~ornp}y with c~~i -E:;t inG st?.t>.: o:r Joc.al heal t-b _, sanitary, or safety eodc spce1i'iC<1iiom; \-;hi,:h <U"'C' so1c:ty necessc:~ry to assure safe 1ivinl; cond:ttion!':, or (2) Any nl ter::it ion of a structure l.istr)d on the National Registe~ of Historic Places or a State Inventory of Histor:i_c Plae:(~S, ' 1V;n·j n.ncc 11 rnnnn~-' a grant of rc>l ief from the requil'O!n(-mts of tlli"s chupter whj_ch pcrmi ts construct-ion ir1 a manner that would oth('rwise be prohibited by this chapter. Section 16.52.050 Application of Chapter. This Chapter shall apply to all areas of special flood hazards within the jurisdiction of the City of Palo Alto. Section 16.52.060 Establishment of Special Flood Hazard Areas. The areas of special flood hazard identified by the Federal Insurance Admini~:tration in a sc-.ientific and engineering report ent:i.tled "The Flood Insurance Study for the City of Palo Alto,'' dated August 15! 1979~ with accompanying flood insurance rate maps is hereby adopted by refer­ ence and declared to be a part of this chapter. The flood insurance study is on file at the Department of Public Works of the City of Palo Alto, Civic Center~ 250 Hamilton Avenue~ Palo Alto, California. Section 16.52,070 Compliance with Regulations. No structure or land shall hereafter be constructedl lpcated, extended~ converted, or altered without full compliance with the provisions of this chapter and other applicable regulations. Section 16.52.080 Abrogation of Easements and Greater Restrictions~ This chapter is not intended to repeal, abrogate, or impair any existing easements, covenants, or deed restrictions. However, where this ordina~ce and another ordinance, easement, covenant~ or deed restriction conflict or overlap, whichever imposes the more stringent restrictions shall prevail. --4 - .. ~-~-~-~---~---~-----~---------------------... Section 16.52.090 Intei'pretation, ln 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 provisions of law, Section 16.52.100 Disclaimer of Liability. The degree of flood protection required by this chapter is considered reasonable for regula­ tory purposes and is based on scientific and engineering considerations. Larger floods than those upon which these regtllations are based can and will occur on rare occasions. Flood heights may be increased by man-made or natural ca11ses. This ordinance does not imply that land outside the areas of special flood hazards or uses permitted within such areas wi'! 1 br~ free f:rom flooding or flood da.mn .. ges. This ord1nance shall not cre;;~te Uability on the part of r!w City of Palo Alto, any officer or employee thert'oJ, nr the Yf.>dt."'ral 1n.'nrra1H'O Admin:i_stration, for any flood damages that result frcJm reliance on this chapter or any administrative decision lawfully made thereunder. All persons per­ forming any construction within the City of Palo Alto should and are advised to detEJrrnine to their own sat isfaet ion the: level of flood pro-· tection in addition to that requir~d hy this ct1apter necessary or de­ sirable to insure protection of their property. Section 16,52.110 Deveiopment Per~it Required. A development permit shall be obtained before construction or devrlopment hegins within any area of special flood hazard established by Section 16.52.060. Applications for a development permit shall be made with the Chief Building Official in such form and upon such applicatior1 as may be specified by the Chief Building Official. ln the case of any construc­ tion or development for which a permit such as a building~ electrical, plumbing or grad.ing permit is otherwise required by this ti"!:le, said permit shall constitute the development permit for the project and no separate application shall be required. I~ such event, the provisions of this chapter shall be complied with in the course of issuance of such permit and such permit shall be conditioned upo" such provisions as may be required oy this chapter. In addition to any other require­ ments, the Chief Building Official may require the submission of such materials as are necessary to insure compliance with the provisions of this chapter, which may include, but shall not be limited to: plans drawn to scale showing the nature, locat.ion, dime~sions h,Od elevations of the area j.n question; existing or proposed structures, fill, storage of materials, arainage ~acilities; and the location of the foregoing. In all cases, the following information shall be required: (a) Elevation in relation to mean sea level, of the lowest hab­ itable floor (including basement) of all structures; (b) El,evation in relation to ~an sea level to which any struc­ ture has been or :ts proposed to be floodproofed; (c) Certification by a registered professional engineer or archi­ tect that the floodproofing methods for any nonresi.dential structure meet the floodproofing criteria contained in Section 16.52.150(b); aP.d (d) Deacription of the extant to which any water course will be altered or relocated as a result of the proposed development. - 5 - ,· Section 16.52.120 Designation of A~~inistrator. The City Engineer is hereby appointed to administer a.nd implement this chapter by reviewing all development permit applications in accordance with the provisions · of this chapter. The duties of the City Engineer in this respect shall include, but not be limited to the following: (a) Permit Review (1) Review all development permits to determine that tbe permit requirements of this chapter have been satisfied. (2) Review all development permits to determine if the pro­ posed development adversely affects the flood carry.i.ng capacity of the area of special flood hazard. For pur­ poses oJ this ordinance, "adversely af.fec.t.s" means that the cumulative effect of the proposed development when combined with all othet· existing and ant h~ipated deV{-:!lop­ ment will not increase the water surface elevation of the base flood morA than one fool ~t any point. (b) Use of Other Base Flood Dsta. When bas0 flood 0!evation data has not been provided in accordance ~ith Section 16.52.060 l''LOOD HAZARD AREAS ESTABLlShED, the City Yng:ineEH' shall ob­ tain, review, and reasonably utiliz8 any base flood elevation data available from a federal, state or other sourcH, in order to administer Sections l6,52.150(a) and (b). (c) Information to be Obtained and Maintained (1) Obtain and record the actual elevation tln relation to mean sea level) of the lc·~·est habitable floor ( incltlding basement) of all new or substantially improved structures. ( 2) For all new or subs t ant l.ally improved f loodproofed st ruc.­ tures: (i) verify and record the actual elevation (in relation to mean sea level), and (ii) maintain the floodproofing certifications required in Section 18.52.110(c). (3) Maintain for public inspection all records pertaining to the provisions of this ordinance. (d) Alteration of Watercourses (1) Notify ad,jacent communities and the Santa Clara Valley Water District and the State Water Resources Board 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 tha.t 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 ap­ pears to be a conflict between a mapped boundary and actual field conditions). -6 - . ' ' ' . Section 16.52.130 Variances. (a) Any applicant for a development permit pursuant to this chap­ ter may apply for a variance from any of the provisions of this chapter. (b) Variances shall only be issued upon: (1) A showing of good apd sufficient cause; (2) A determination that failure to grant the variance would result in exceptional hardship to the applicant; and (3) A determination that the granting of a variance will not result in incteased flood heights$ additional threats to public safety, extraordinary public expense, nuisancest fraud on or victimization of the public, or conflict with existing local laws or ordinances. (c) In determining whether to grant a variance, the City Engin0er shall take the following items into consideration: (1) the danger that materials may be swept onto other la11ds to the injury of others; (2) the danger to life and property due to flooding or ero­ sion damage; (3) the susceptibility of the proposed facility and its con­ tents to flood damag~:.1 and the eff~;ct of such dRmage on the individual owner; (4) 1he importance of the services provided by the proposed .facility to the community; (5) the necessity to the facility of a waterfront location, where applicable; (6) the availability of alternative locations 1 for the pro­ posed use which are not subject to flooding or erosion damage; (7) the compatibility of the proposed use with e~.isting and an+,icipated development; (8) the relationship of tbe proposed use to the comprehensive plan and flood pla.in management program for that area; (9) the sifety of access to the property in times of flood for ordinary and emergency vehicles; (10) tbe expected heights~ velocity 1 duration~ rate of rise, and sediment transport of the flood waters and the effects of wave action, if applicable, expected at the site; and, (11) 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. (12) the size and location of the project - 7 - .. ' . . ' ' ' Generally, variances may ba issued for new construction and substantial improvements to be erected on a lot of one-half acre or less in size contiguous to and surrounded by lots with existing structures constructed below the base flood level, providing items (1-11) of this Section have been fully considered~ As the lot size increases beyond the one-half acre, the technical justifica.tion required for issning the variance increases. (d) Applications for variances shall be made with the City Engineer upon such forms as may bo prescribed by the City Engineer and shall be made at the time of application for the develop­ ment permit. Issuance of any variance may be made subject to such conditions as the City Engineer deems necessary to further the purposes of this chapter. The City Engineer shall maintaj.n the records of all appeal actions and report any variances to the Federal Insurance Administration upon request. Any applicant to whom a variance is granted sha11 be given written notice that the structure will be pArmitted to be built with a lowest floor elevation below the base flood elevation and the eost of .flood insurance wi 11 be corru"'lH~nsura te with the increased risk resulting from the reduced lowest floor elevation. Notice of the issuance of such variances shall be recorded in the office of the County Recorder of the County of Santa,Clara. (e) Notwithstanding the foregoing, the iss~Ance of varlancos shall be subject to the following: (l) Variances shall not be issued within any designated floodway if aQy increase in flood levels during the base flood discharge would result; (2) Variances shall only be issu~d upon the determination that the variance is the minimum necessary, considering the flood hazard, to afford relief; and (3) Variances may be issued for the reconstruction, rehabili­ tati.on or restoration of structures listed on the National Register of Historic Places or the State Inventory of Historic Places) without regard to the provisions of this subsection (b) or the provisions of subsection (d)t provided that in issuing such varianc.e factors numbered one through eleven of subsecti0n (c) shall be taken into consideration. Section 16.52.140 General Standards for Prcject Review. In all areas of special flood hazards, the following standards are required: (a) Anchoring: (1) All n~w construction and substantial improvements shall be anchored to prevent flotation 1 collapse or lateral movement of the structure. (2) All mobile homes shall be anchored to resist flotation, collapse, or lateral movement by providing over-the-top and frame ties to ground anchors. Specific requirements shall be that: (i) ove~-the-top ties be provided at each of the four corners of the mobile home, with two additional ties per side at intermediate locations, with mobile homes less than 50 feet long requiring one additional tia per side; - 8 - I I . ' ' . ' ' ' • • (ii) fram€ ties be provided ~t each corner of the home with five additional ties per side at intermediate points, with mobile homes less than 50 feet long requiring four additional ties per side; (iii.) all components of the anchoring system be capable of carrying a force of 4,800 pounds.; and, (iv) any additions to the mobile home be similarly an­ chored. (b) Construction Materials and Methods (1) All new construction and substantial improvements shall be constructed with materials and utility equipment ~e­ sistant to flood damage. (2) All new construction and substantial improvements shall be constructed using methods and practJces that minimize flood damage. (c) Utili ties {l) All new and replacement water supply systems shall be designed to mj.nimize 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 systems into flood waters; and, (3) On-site waste disposal systems shall be located tu avoid impairment to them or contaminatj.on from them during flooding, 16.52.150 Specific Standards, I~ all areas of special flood hazards where base flood elevation data bas been provided as set forth in Section 16.52.060 or Section 16~52~120(b), the following provisions 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. (b) Non~esidential Construction. New construct~on and substantial improvement of any commercial, industrial or other nonresiden­ tial 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: (l) be floodproofed so that:below the base flood level the structure is watertight with walls substantially imperme­ able to the passa~e of water; (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 -9 - • • . . ' • • satisfied. Such certifications shall be provided to the official as set forth in Section 16~52.120(c)(2). (c) Mobile Homes (1) Mobile homes shall be anchored in accordance with Section 16~52,140(a)(2). (2) For new mobile home parks aud mobile home subdivisions; for expansions to existing mobile home parks and mobile home subdivisions where the :.repair, reconstruction or improvement of the streets, ut.ili ties and pads equals or exceeds 50 percent of value of the streets, utilities and pads before the repair, reconstruction or improve­ ment has commenced; and for mobile homes not placed in a mobile home park or mobile home subdivision 1 require that: (i) stands or lots are elevated on compacted fill or on pilings so that the lowest floor of the mobile home will be at or above the ba.se flood level; (ii) adequate surface drainage and access for a hauler are providedi and, (iii) in the instance of elevation on pil.ings, 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 16.52,160 Shallow Flooding, Lo~ated within the areas of special flood hazard established in Section 16~52.060 are areas designated as shallow flooding, These areas have special flood hazards associated with base flood depths of 1 to 3 feet where a clearly defined channel does not· exist and where the path of flooding is unpredictable and indeterminate; therefore, the following provisions apply: (a) All new construction ~nd substantial improvements of resi~ dential structures shall have the lowest floor, including basement, ~Clavated above the crown o.f the nearest street to or above the depth number specified o.n the community's FIRM, (b) All new construction and substantial improvements of nonresi- dential structures shall: · (1) have the lowest floor~ including basement~ elevated above the crown of tbe nearest street to or above the depth number specified on the FIRM, or (2) together with attendant utility and sanitary facilities be completely floodproofed to or above that level so that any space below that level is watertight with walls substantially impermeable to the passage of water a.nd with structural components having the capability of re­ sisting hydrostatic and bydrodymanic loads and effects or buoyancy. -10 - .. . ' . . ' • • 21.20,310 Flood Hazard Regulations. For the purpose of carrying out the intent of Chapter 16.52 of th.is Code, all subdivisions shall: (a) Be consistent with the need to minimize flood damage; (b) Have public utilities and facilities such as sewer, gas~ electrical, and water systems located and constructed to minimize flood damage; (c) Have adequate drainage provided to reduce exposure to flood damage; and (d) Base flood eJ.evation data shall be provided for subdivision propo8als and other proposed developments which contain at least fifty (50) lots or five (5) acres (whichever is less), EXHIBIT 11 B"