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HomeMy WebLinkAboutMINUTES - 06231987 - T.14 T. -, TO: BOARD OF SUPERVISORS Contra FROM: Harvey E. Bragdon Costa Community Development Director County DATE: June 11, 1987 � ��J SUBJECT: Interim Floodplain Management Ordinance SPECIFIC REQUEST(S) OR RECOMMENDATIONS(S) & BACKGROUND AND JUSTIFICATION RECOMMENDATIONS Staff recommends that the Board of Supervisors: Adopt the 45-day interim emergency Floodplain Management Ordinance. FISCAL IMPACT Staff will be recommending the imposition of Floodplain Permit fees to recover the costs of a County Floodplain Management Program. There would therefore be no financial impact to the County as a result of adopting the Floodplain Management Ordinance if fees are imposed to recover program costs. However, no permit fees are proposed in association with the 45-day interim emergency ordi- nance, in order to allow staff time to develop an appropriate fee structure. There may be minimal costs incurred over this time period, or until the final ordinance is adopted by the Board, related to staff time devoted to implementation of the interim ordinance and program development. BACKGROUND/REASONS FOR RECOMMENDATIONS The Federal Emergency Management Agency (FEMA) recently revised the regulations governing the National Flood Insurance Program (NFIP) , updated the County' s Flood Insurance Rate Map (FIRM) and Floodway Maps to be effective July 16, 1987, and is converting Contra Costa County from the "Emergency" to the "Regular" Flood Insurance Program. CONTINUED ON ATTACHMENT: YES SIGNATURE ,4// Z ;-,4WO-161 - _ RECOMMENDATION OF COUNTY ADMINISTRATOR RECOMMENDATION OF BOARD COMMI E APPROVE OTHER SIGNATURE(S) : ACTION OF BOARD ON June 23. 1987 APPROVED AS RECOMMENDED _x OTHER x The Board held a public_hearing on the proposed ordinance. Frank Mikesell and M. Miranda appeared and commented. The Board closed the public hearing, adopted Ordinance 87-45 and _ set._.1ijlv__7,-1987, at 10:30 a.m. to accept further comments. VOTE OF SUPERVISORS I HEREBY CERTIFY THAT THIS IS A X UNANIMOUS (ABSENT I ) TRUE AND CORRECT COPY OF AN AYES: NOES: ACTION TAKEN AND ENTERED ON THE ABSENT: ABSTAIN: MINUTES OF THE BOARD OF SUPERVISORS ON THE DATE SHOWN. cc: Community Development ATTESTED June 23, 1987 Public 14orks PHIL BATCHELOR, CLERK OF County Counsel THE BOARD OF SUPERVISORS Building Inspection AND COUNTY ADMINISTRATOR County Administrator BY , DEPUTY :krc As a result of these actions, Contra Costa County is now required to adopt a legally enforceable floodplain management ordinance, in com- pliance with the revised National Flood Insurance Program rules, by July 16, 1987 in order to continue participation in the National Flood _Insurance Program. In order to satisfy this requirement, and because of the 30-day period which must elapse for an ordinance to take effect following its adoption, staff is presenting a 45-day interim emergency ordinance, to take effect immediately upon adoption, for the Board' s consideration. The attached Floodplain Management Ordinance is based on a model ordi- nance prepared by the California Department of..Water Resources which meets all of the current minimum NFIP regulations. It was modified to reflect existing flood hazard conditions in the County and to incorporate technical amendments made by affected County departments, (Flood Control and Water Conservation District, Public Works Department; Building Inspection Department; Environmental Health Services Division, Health Services Department; Risk Management, Administrator' s Office; County Counsel; and the Community Development Department) . The proposed Floodplain Management Ordinance contains the following key provisions- 0 Establishes a County Floodplain Administrator within the Community Development Department. o Regulates development (defined to include activities such as grading, paving and filling in addition to new construction or substantial improvements to existing structures) in flood hazard areas of the County by creating a Floodplain Permit process. o Establishes construction standards, including standards related to anchoring of structures, construction materials and methods, building elevation and floodproofing, to reduce flood damage in flood hazard areas. 0 Establishes flood damage reduction standards for utilities, subdivisions and mobile homes at specific points in the de- velopment process. o Creates special development standards for areas classified as Floodways and Coastal High Hazard Areas. JH/jb Misc. /Janebrd ► (e1 1 ORDINANCE 87-45 FLOODPLAIN MANAGEMENT ORDINANCE SECTION 1.0 STATUTORY AUTHORIZATION, FINDINGS OF FACT, PURPOSE AND METHODS 1.1 STATUTORY AUTHORIZATION. This ordinance is designed to promote the public health, safety and general welfare of the citizens of Contra Costa County and is enacted pursuant to the authority of United States Code, Title 43, Chapter 50 (42 U.S.C. §§4001-4128; see especially 42 U.S.C. §4022) ; Government Code Section 65560(b)(4) ; Government Code, Title 7, Division 1, Chapter 4 (Gov. Code, §§ 65800=65912; see especially Gov. Code, § 65850) ; and California Constitution, Article XI, Section 7. Therefore, the Board of Supervisors of Contra Costa County ordains as follows: 1.2 FINDINGS OF FACT. A. The flood hazard areas of Contra Costa County 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. B. These flood losses are caused by inadequate drainage facilities and the cumulative effect of obstructions in areas of special flood hazards which increase flood heights and velocities. These losses may result when structures are inadequately anchored. These flood losses may result in damage to property in other areas. Structures that are inadequately floodproofed, elevated or otherwise protected from flood damage also contribute to the flood loss. C. Contra Costa County has experienced serious flooding which has resulted in substantial property damage and the potential for loss of life. Delay in adoption of this floodplain management ordinance would result in issuance of additional ministerial building permit approvals and discretionary subdivision, use permit, and variance permit approvals along with other applicable entitlements within flood-prone areas which would expose structures and people to increased flood hazards resulting in property damage and/or loss of life. The County of Contra Costa must adopt a legally enforceable floodplain management ordinance which fully complies with the recently revised rules of the National Flood Insurance Program administered by the Federal Emergency Management Administration by July 16, 1987, to continue participation in said program. The continued participation of the County in the National Flood Insurance Program is desirable and promotes the public health, safety, and welfare in that it provides insurance and federal assistance in the event of flood(s) within the County's jurisdiction. In the absence of such insurance, the County's vulnerability to damage and loss resulting from flood events, may be substantial and potential flood damage represents an immediate threat to the public health, safety and welfare. 1.3 STATEMENT OF PURPOSE. It is the purpose of this ordinance 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 use and development of areas of special flood hazard subject to review by permit and flood damage reduction standards so as to minimize future flood blight areas; G. To provide to the general public, upon request, information regarding special flood hazard areas in the unincorporated areas of the County; and H. To clearly establish that those who occupy the areas of special flood hazard should assume responsibility for their actions and the losses they may suffer. They would be required to comply with this ordinance. 1.4 METHODS OF REDUCING FLOOD LOSSES. In order to accomplish its purpose, this ordinance 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, flood heights or velocities; B. Requiring that uses vulnerable to floods, including facilities such as utilities which serve such uses, be protected against flood damage at the time of initial construction; Page 2 87-45 C. Requiring that the design of streets and public access facilities include consideration of accessibility under the base flood conditions for emergency service vehicles and any rescue and relief operations; D. Controlling the alteration of natural floodplains, stream channels, and natural protection barriers, which help accommodate or channel flood waters; E. Controlling filling, grading, dredging, and other development which may increase flood damage; and, F. Preventing or regulating the construction of flood barriers which will unnaturally divert flood waters or which may increase flood hazards in other areas. G. Requiring orderly development of drainage facilities within watershed areas as development occurs. Page 3 87-45 SECTION 2.0 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" means a request for a review of the Floodplain Administrator's interpretation of any provision of this ordinance or a request for a variance. "Area of shallow flooding" means a designated A0, AH or VO Zone on the Flood Insurance Rate Map (FIRM) . The base flood depths range from one to three feet; a clearly defined channel does not exist; the path of flooding is unpredictable and indeterminate; and velocity flow may be evident. "Base flood" means the flood having a 1 percent chance of being equalled or exceeded in any given year (also called the "100-year flood") . "Basement" means any area of the building having its floor subgrade (below ground level ) on all sides. "Breakaway walls" are any type of walls, whether solid or lattice, and whether constructed of concrete, masonry, wood, metal , plastic or any other suitable building material which is not part of the structural support of the building and which is designed to break away under abnormally high tides or wave action without causing any damage to the structural integrity of the building on which they are used or any buildings to which they might be carried by flood waters. A breakaway wall shall have a safe design loading resistance of not less than ten and no more than twenty pounds per square foot. Use of breakaway walls must be certified by a registered engineer or architect and shall meet the following conditions: 1. Breakaway wall collapse shall result from a water load less than that which would occur during the base flood; and 2. The elevated portion of the building shall not incur any structural damage due to the effects of wind and water loads acting simultaneously in the event of the base flood. "Coastal high hazard area" is the area subject to high velocity waters, including coastal and tidal inundation or tsunamis. The area is designated on a Flood Insurance Rate Map (FIRM) as Zone VI-V30, VE or V. "Development" means 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. Page 4 87-45 "Flood or flooding' means a general and temporary condition of partial or complete inundation of normally dry land areas from (1) the overflow of flood waters, (2) the unusual and rapid accumulation or runoff of surface waters from any source, and/or (3) the collapse or subsidence of land along the shore of a lake or other body of water as a result of erosion or undermining caused by waves or currents of water exceeding anticipated cyclical levels or suddenly caused by an unusually high water level in a natural body of water, accompanied by a severe storm, or by an unanticipated force of nature, such as flash flood or an abnormal tidal surge, or by some similarly unusual and unforeseeable event which results in flooding as defined in this definition. "Flood Boundary and Floodway Map" means the official map described in Section 3.2 on which the Federal Emergency Management Agency or Federal Insurance Administration has delineated both the areas of flood hazard and the floodway. "Flood Insurance Rate Map (FIRM)" means the official map described in Section 3.2 on which the Federal Emergency Management Agency or Federal Insurance Administration has delineated both the areas of special flood hazards and the risk premium zones applicable to the community. "Flood Insurance Study" means the official report described in Section 3.2 provided by the Federal Insurance Administration that includes flood profiles, the FIRM, the Flood Boundary and Floodway Map, and in some areas, the water surface elevation of the base flood. "Floodplain or flood-prone area" means any land area susceptible to being inundated by water from any source (see definition of "flooding") . "Floodplain management" means the operation of an overall program of corrective and preventive measures for reducing flood damage, including but not limited to emergency preparedness plans, flood control works and floodplain management regulations. "Floodplain management regulations" means zoning ordinances, subdivision regulations, building codes, health regulations, special purpose ordinances (such as floodplain ordinance, grading ordinance and erosion control ordinance) and other applications of police power. The term describes such state or local regulations in any combination thereof, which provide standards for the purpose of flood damage prevention and reduction. "Floodplain permit" means a permit required of all development which occurs in any area designated by FEMA as a Floodway, Coastal High Hazard Area, Zone A, A0, Al-A30, A99, AH, V, V0, or V1-V30, and other areas adopted by the Zoning Administrator. "Floodproofing" means any combination of structural and nonstructural additions, changes, or adjustments to structures which reduce or eliminate flood damage to real estate or improved real property, water and sanitary facilities, structures and their contents. Page 5 87-45 "Floodway" 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. Also referred to as "Regulatory floodway." "Functionally dependent use" means a use which cannot perform its intended purpose unless it is located or carried out in close proximity to water. The term includes only docking facilities, port facilities that are necessary for the loading and unloading of cargo or passengers, and ship building and ship repair facilities, but does not include long-term storage or related manufacturing facilities. "Highest adjacent grade" means the highest natural elevation of the ground surface prior to construction next to the proposed walls of a structure. "Lowest floor" means the lowest floor of the lowest enclosed area (including basement) . An unfinished or flood resistant enclosure, usable solely for parking of vehicles, building access or storage in an area other than a basement area is not considered a building's lowest floor; provided, that such enclosure is not built so as to render the structure in violation of the applicable non-elevation design requirements of this ordinance. "Manufactured home" means a structure, transportable in one or more sections, which is built on a permanent chassis and is designed for use with or without a permanent foundation when connected to the required utilities. For floodplain management purposes the term "manufactured home" also includes park trailers, travel trailers and other similar vehicles placed on a site for greater than 180 consecutive days. "Manufactured home park or subdivision" means a parcel (or contiguous parcels) of land divided into two or more manufactured home lots for sale or rent. "Mean sea level" means, for purposes of the National Flood Insurance Program, the National Geodetic Vertical Datum (NGVD) of 1929 or other datum, to which base flood elevations shown on a community's Flood Insurance Rate Map are referenced. "New construction" means, for floodplain management purposes, structures for which the "start of construction" commenced on or after the effective date of a floodplain management regulation adopted by this community. "One hundred year flood" or "100-year flood" means a flood which has a one percent annual probability of being equalled or exceeded. It is identical to the "base flood," which will be the term used throughout this ordinance. "Person" means an individual or his agent, firm, partnership, association or corporation, or agent of the aforementioned groups, or this state or its agencies or political subdivisions. Page 6 87-45 "Remedy a violation" means to bring the structure or other development into compliance with State or local floodplain management regulations, or, if this is not possible, to reduce the impacts of its noncompliance. Ways that impacts may be reduced include protecting the structure or other affected development from flood damages, implementing the enforcement provisions of the ordinance or otherwise deterring future similar violations, or reducing Federal financial exposure with regard to the structure or other development. "Riverine" means relating to, formed by, or resembling a river (including tributaries) , stream, brook, etc. "Sand dunes" means naturally occurring accumulations of sand in ridges or mounds landward of the beach. "Special flood hazard area (SFHA)" means an area having special flood or flood-related erosion hazards, and shown on an FHBM or FIRM as Zone A, A0, A1-30, A99, AH, V0, V1-30 or V. "Start of Construction" includes substantial improvement, and means the date the building permit was issued, provided the actual start of construction, repair, reconstruction, placement, or other improvement was within 180 days of the permit date. The actual start means either the first placement of permanent construction of a structure on a site, such as the pouring of slab or footings, the installation of piles, the construction of columns, or any work beyond the stage of excavation; or the placement. of a manufactured home on a foundation. Permanent construction does not include land preparation, such as clearing, grading and filling; nor does it include the installation of streets and/or walkways; nor does it include excavation for a basement, footings, piers, or foundations or the erection of temporary forms; nor does it include the installation on the property of accessory buildings, such as garages or sheds not occupied as dwelling units or not part of the main structure. "Structure" means a walled and roofed building, including a gas or liquid storage tank, that is principally above ground, as well as a manufactured home. "Substantial improvement" means 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 purposes of this definition "substantial improvement" is considered to occur when the first alteration of any wall , ceiling, floor, 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: Page 7 87-45 (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 or a State Inventory of Historic Places. "Variance" means a grant of relief from the requirements of this ordinance which permits construction in a manner that would otherwise be prohibited by this ordinance. "Violation" means the failure of a structure or other development to be fully compliant with the community's floodplain management regulations. A structure or other development without the elevation certificate, other certifications, or other evidence of compliance required in this ordinance is presumed to be in violation until such time as that documentation is provided. Page 8 87-45 SECTION 3.0 GENERAL PROVISIONS 3.1 LANDS TO WHICH THIS ORDINANCE APPLIES. This ordinance shall apply to all areas of special flood hazards within the jurisdiction of Contra Costa County, as shown on the maps described in Section 3.2. 3.2 BASIS FOR ESTABLISHING THE AREAS OF SPECIAL FLOOD HAZARD. The areas of special flood hazard have been identified by the Federal Emergency Management Agency or the Federal Insurance Administration in a scientific and engineering report entitled "Flood Insurance Study for Contra Costa County, Unincorporated Areas," dated July 16, 1987, with accompanying Flood Insurance Rate Map and Flood Boundary and Floodway Map of same date, which study and maps are hereby adopted by reference and declared to be a part of this ordinance. This Flood Insurance Study and accompanying maps are on file at the Contra Costa County Community Development Department, 4th Floor North Wing, 651 Pine Street, Martinez. This Flood Insurance Study is the minimum area of applicability of this ordinance and may be supplemented by studies for other areas which allow implementation of this ordinance and which are recommended to the Zoning Administrator by the Floodplain Administrator. 3.3 COMPLIANCE. No structure or land shall hereafter be constructed, located, extended, converted, or altered without full compliance with the terms of this ordinance and other applicable regulations. Violations of the requirements (including violations of conditions and safeguards established in connection with conditions) shall constitute an infraction punishable as provided in Government Code Section 25132. Nothing herein shall prevent the Contra Costa County Board of Supervisors from taking such lawful action as is necessary to prevent or remedy any violation. 3.4 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 another ordinance, easement, covenant, or deed restriction conflict or overlap, whichever imposes the more stringent restrictions shall prevail . 3.5 INTERPRETATION. In the interpretation and application of this ordinance, 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. Page 9 87-45 3.6 WARNING AND DISCLAIMER OF LIABILITY. 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 areas of special flood hazards or uses permitted within such areas will be free from flooding or flood damages. This ordinance shall .not create liability on the part of Contra Costa County, any officer or employee thereof, or the Federal Insurance Administration, for any flood damages that result from reliance on this ordinance or any administrative decision lawfully made thereunder. 3.7 SEVERABILITY. This ordinance and the various parts thereof are hereby declared to be severable. Should any section of this ordinance be declared by the courts to be unconstitutional or invalid, such decision shall not affect the validity of the ordinance as a whole, or any portion thereof other than the section so declared to be unconstitutional or invalid. Page 10 87-45 SECTION 4.0 ADMINISTRATION 4.1 ESTABLISHMENT OF FLOODPLAIN PERMIT. A Floodplain Permit shall be obtained from the Contra Costa County Community Development Department before construction, a grading permit, building permit, initial use under a variance permit, land use permit or development permit, and, prior to filing of a Final Map or a Parcel Map, or development begins within any area of special flood hazards established in Section 3.2. Application for a Floodplain Permit shall be made on forms furnished by the Floodplain Administrator, in the Community Development Department of Contra Costa County and may include, but not be limited to: plans in triplicate drawn to scale showing the nature, location, dimensions, and elevation of the area in question; existing or proposed structures, fill , storage of materials, drainage facilities; and the location of the foregoing. Specifically, the following information is required: A. Proposed elevation in relation to mean sea level , of the lowest floor (including basement) of all structures; in Zone AD or V0, elevation of highest adjacent grade and proposed elevation of lowest floor of all structures. B. Proposed elevation in relation to mean sea level to which any structure will be floodproofed; C. All appropriate certifications listed in Section 4.3.D of this ordinance; and D. Description of the extent to which any watercourse will be altered or relocated as a result of proposed development. 4.2 DESIGNATION OF THE FLOODPLAIN ADMINISTRATOR. The Director of the Community Development Department's designee is hereby appointed as the Floodplain Administrator to administer and implement this ordinance by granting or denying Floodplain Permits in accordance with its provisions. 4.3 DUTIES AND RESPONSIBILITIES OF THE FLOODPLAIN ADMINISTRATOR. The duties and responsibilities of the Floodplain Administrator shall include, but not be limited to: A. Permit review. 1. Review of all Floodplain Permits to determine that the permit requirements of this ordinance have been satisfied; 2. Require submittal of a written statement by each applicant that all other required State and Federal permits have been obtained; Page 11 87-45 3. Review Floodplain Permits for compliance with Federal Emergency Management Agency requirements for elevation of structures above the floodplain plus freeboard. 4. Review Floodplain Permits for compliance with Federal Emergency Management Agency requirements so that the proposed development does not adversely affect the carrying capacity of the floodway. For purposes of this ordinance, "adversely affect" means that the cumulative effect of the proposed development, when combined with all other existing and anticipated development, will not increase 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 3.2, the Floodplain Administrator shall obtain, review, and reasonably utilize any base flood elevation and floodway data available from a Federal , State, or other source, in order to administer Section 5.0. C. Whenever a watercourse is to be altered or relocated: 1. Notify Contra Costa County Flood Control and Water Conservation District, adjacent communities and the California Department of Water Resources prior to such alteration or relocation of the watercourses, and submit evidence of such notification to the Federal Insurance Administration; 2. Require that the flood carrying capacity of the altered or relocated portion of said watercourse is maintained. D. Obtain and maintain for public inspection and make available as needed: 1. The certification required in Section 5.1.C.1 (floor elevations) ; 2. The certification required in Section 5.1.C.2 (elevations in areas of shallow flooding) ; 3. The certification required in Section 5.1.C.3.c (elevation of floodproofing of nonresidential structures) ; 4. The certification required in Section 5.1.C.4.a or 5.1.C.4.b (wet floodproofing standard) ; 5. The certified elevation required in Section 5.3.6 (subdivision standards) ; 6. The certification required in Section 5.5.A (floodway encroachments) ; and Page 12 87-45 7. The information required in Section 5.6.F (coastal construction standards). E. 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 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 6.0. F. Take action determined to be appropriate to remedy violations of this ordinance as specified in Section 3.3 herein with the assistance of the Code Enforcement Officer. Page 13 87-45 SECTION 5.0 PROVISIONS FOR FLOOD HAZARD REDUCTION 5.1 STANDARDS OF CONSTRUCTION. In all areas of special flood hazards, the following standards are required: A. Anchoring. 1. All new construction and substantial improvements shall be anchored to prevent flotation, collapse or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy. 2. All manufactured homes shall meet the anchoring standards of Section 5.4. 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. 3. All new construction and substantial improvements shall be constructed with electrical , heating, ventilation, plumbing, and air conditioning equipment and other service facilities that are designed and/or located so as to prevent water from entering or accumulating within the components during conditions of flooding. 4. Require within Zones AH, AO or V0, adequate drainage paths around structures on slopes to guide flood waters around and away from proposed structures. C. Elevation and Floodproofing 1. New construction and substantial improvement of any structure shall have the lowest floor, including basement, elevated to or above the base flood elevation. Nonresidential structures may meet the standards in Section 5.1.C.3. Upon the completion of the structure, the elevation of the lowest floor including basement shall be certified by a registered professional engineer or surveyor, or verified by the community building inspector to be properly elevated. Such certification or verification shall be provided to the Floodplain Administrator. Page 14 87-45 2. New construction and substantial improvement of any structure in Zone AH, AO or VO shall have the lowest floor, including basement, elevated above the highest adjacent grade at least as high as the depth number specified in feet on the FIRM, or at least two feet if no depth number is specified. Nonresidential structures may meet the standards in Section 5.1.C.3. Upon the completion of the structure, the elevation of the lowest floor including basement shall be certified by a registered professional engineer or surveyor, or verified by the community building inspector to be properly elevated. Such certification or verification shall be provided to the Floodplain Administrator. 3. Nonresidential construction shall either be elevated in conformance with Section 5.1.C.1 or .2 or together with attendant utility and sanitary facilities: a. Be floodproofed so that below the base flood level the structure is watertight with walls substantially impermeable to the passage of water; b. Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy; and C. Be certified by a registered professional engineer or architect that the standards of this subsection are satisfied. Such certification shall be provided to the Floodplain Administrator. 4. Require, for all new construction and substantial improvements, that fully enclosed areas below the lowest floor, that are subject to flooding, shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwaters. Designs for meeting this requirement must either be certified by a registered professional engineer or architect or meet or exceed the following minimum criteria: a. Either a minimum of two openings having a total net area of not less than one square inch for every square foot of enclosed area subject to flooding shall be provided. The bottom of all openings shall be no higher than one foot above grade. Openings may be equipped with screens, louvers, valves or other coverings or devices provided that they permit the automatic entry and exit of floodwaters; or b. Be certified to comply with a local floodproofing standard approved by the Federal Insurance Administration. 5. Manufactured homes shall also meet the standards in Section 5.4. Page 15 87-45 5.2 STANDARDS FOR UTILITIES A. All new and replacement water supply and sanitary sewage systems shall be designed to minimize or eliminate infiltration of flood waters into the system and discharge from systems into flood waters. B. On-site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding. C. On-site water supply systems shall be located to avoid impairment to them or contamination of them during a flood. 5.,3 STANDARDS FOR SUBDIVISIONS A. All Tentative Maps for preliminary subdivision proposals shall identify the flood hazard area and the elevation of the base flood. B. All final subdivision improvement plans will provide the elevation of proposed structure(s) , pads and streets. If the site is filled above the base flood, the final pad elevations shall be certified by a registered professional engineer or surveyor and provided to the Floodplain Administrator. C. All subdivision proposals shall be consistent with the need to minimize flood damage. D. All subdivision proposals shall have public utilities and facilities such as road, sewer, gas, electrical and water systems located and constructed to minimize flood damage. E. All subdivisions shall provide adequate drainage to reduce exposure to flood hazards. 5.4 STANDARDS FOR MANUFACTURED HOMES. All new and replacement manufactured homes and additions to manufactured homes shall : A. Be elevated so that the lowest floor is at or above the base flood elevation; and B. Be securely anchored to a permanent foundation system to resist flotation, collapse or lateral movement. 5.5 FLOODWAYS. Located within areas of special flood hazard established in Section 3.2 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: Page 16 87-45 A. Prohibit encroachments, including fill , new construction, substantial improvements, and other development unless certification by a registered professional engineer or architect is provided demonstrating that encroachments shall not result in any increase in flood levels during the occurrence of the base flood discharge. B. If Section 5.5.A is satisfied, all new construction and substantial improvements shall comply with all other applicable flood hazard reduction provisions of Section 5. 5.6 COASTAL HIGH HAZARD AREAS. Within coastal high hazard areas established in Section 3.2, the following standards shall apply: A. All new construction and substantial improvements shall be elevated on adequately anchored pilings or columns and securely anchored to such pilings or columns so that the lowest horizontal portion of the structural members of the lowest floor (excluding the pilings or columns) is elevated to or above the base flood elevation. B. All new construction shall be located on the landward side of the reach of mean high tide. C. All new construction and substantial improvements shall have the space below the lowest floor free of obstructions or constructed with breakaway walls. Such temporarily enclosed space shall not be used for human habitation. D. Fill shall not be used for structural support of buildings. E. Man-made alteration of sand dunes which would increase potential flood damage is prohibited. F. The Floodplain Administrator shall obtain and maintain the following records: 1. Certification by a registered engineer or architect that a proposed structure complies with Section 5.6.A. 2. The elevation (in relation to mean sea level ) of the bottom of the lowest structural member of the lowest floor (excluding pilings or columns) of all new and substantially improved structures; and whether such structures contain a basement. Page 17 87-45 SECTION 6.0 VARIANCE PROCEDURE 6.1 APPEAL BOARD A. The Zoning Administrator of Contra Costa County shall hear and decide appeals and requests for variances from the requirements of this ordinance. B. The Zoning Administrator shall hear and decide appeals when it is alleged there is an error in any requirement, decision, or determination made by the Floodplain Administrator in the enforcement or administration of this ordinance. C. In passing upon such applications, the Zoning Administrator shall consider all technical evaluations, all relevant factors, standards specified in other sections of this ordinance, and: 1. The danger that materials may be swept onto other lands to the injury of others; 2. The danger of life and property due to flooding or erosion damage; 3. The susceptibility of the proposed facility and its contents to flood damage and the effect of such damage on the individual owner; 4. The 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 for the proposed use which are not subject to flooding or erosion damage; 7. The compatibility of the proposed use with existing and anticipated development; 8. The relationship of the proposed use to the comprehensive plan and floodplain management program for that area; 9. The safety of access to the property in time of flood for ordinary and emergency vehicles; 10. The expected heights, velocity, duration, rate of rise, and sediment transport of the flood waters expected at the site; and, Page 18 87-45 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 system, and streets and bridges. D. Generally, variances may be 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 , provided items 6.1.C.1. through 6.1.C.11 have been fully considered. As the lot size increases beyond one-half acre, the technical justification required for issuing the variance increases. E. Upon consideration of the factors of Section 6.1.0 and the purposes of this ordinance, the Zoning Administrator may attach such conditions to the granting of variances as it deems necessary to further the purposes of this ordinance. F. Appeals from Zoning Administrator decisions may be made in the time and manner provided in Contra Costa County Ordinance Code Article 26-2.24 to the Planning Commission and Board of Supervisors upon payment of prescribed fees. G. The Floodplain Administrator shall maintain the records of all appeal actions and report any variances to the Federal Insurance Administration upon request. 6.2 CONDITIONS FOR VARIANCES A. Variances may be issued for the reconstruction, rehabilitation or restoration of structures listed in 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. B. Variances shall not be issued within any designated floodway if any increase in flood levels during the base flood discharge would result. C. Variances shall only be issued upon a determination that the variance is the minimum necessary, considering the flood hazard, to afford relief. D. Variances shall only be issued upon: 1. A showing of good and sufficient cause; 2. A determination that failure to grant the variance would result in exceptional hardship to the applicant; and Page 19 87-45 3. 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, or conflict with existing local laws or ordinances. E. Variances may be issued for new construction and substantial improvements and for other development necessary for the conduct of a functionally dependent use provided that the provisions of Section 6.2.A through 6.2.D are satisfied and that the structure or other development is protected by methods that minimize flood damages during the base flood and create no additional threats to public safety. F. 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 regulatory flood elevation and that the cost of flood insurance will be commensurate with the increased risk resulting from the reduced lowest floor elevation. A copy of the notice shall be recorded by the Floodplain Administrator in the office of the Contra Costa County Recorder and shall be recorded in a manner so that it appears in the chain of title of the affected parcel of land. JH:jn 3:flood.ord 6/23/87 Page 20 87-45 SECTION 7.0 EFFECTIVE DATE 7.1 This ordinance shall become effective immediately after passage, and shall be operative for 45 (forty-five) days after which time it may be extended. Within 15 days of passage, this ordinance shall be published once, with the names of the Supervisors voting for and against it, in the Contra Costa Times, a newspaper of general circulation published in this county. The Clerk of the Board shall promptly file a certified copy of this ordinance with the County Recorder. PASSED AND ADOPTED ON June 23 , 1987 by the following vote: AYES: Supervisors Fanden, Schroder, Torlakson and McPeak NOES: None ABSENT: Supervisor Powers ABSTAIN: None ATTEST: PHIL BATCHELOR, Clerk of the Board of Supervisors and County Administrator. B o By: Deputy Board Chair JH:jn 3:flood.ord 6/23/87 Page 21 87-45