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Oklahoma's Floodplain Management 101

Chapter 3 Appendix

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Appendix 3-1: State of Oklahoma Model D Ordinance

Updated December 8, 2004

FLOODPLAIN MANAGEMENT REGULATONS

ARTICLE I STATUTORY AUTHORIZATION, FINDINGS OF FACT, PURPOSE AND METHODS

SECTION A. STATUTORY AUTHORIZATION

The Legislature of the State of Oklahoma has in (statutes) 82 O.S. §1601-1618, as amended, Chapter 23 delegated the responsibility of local governmental units to adopt regulations designed to minimize flood losses. Therefore, the (name of community goes here), Oklahoma, does ordain as follows:

SECTION B. FINDINGS OF FACT

  1. The flood hazard areas of (Name of community goes here) are subject to periodic inundation, which results in loss of life and property, health and safety hazards, disruption of commerce and governmental services, and extraordinary public expenditures for flood protection and relief, all of which adversely affect the public health, safety and general welfare.
  2. These flood loses are created by the cumulative effect of obstructions in floodplains which cause an increase in flood heights and velocities, and by the occupancy of flood hazards areas by uses vulnerable to floods and hazardous to other lands because they are inadequately elevated, floodproofed or otherwise protected from flood damage.

SECTION C. 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 to:

  1. Protect human life and health;
  2. Minimize expenditure of public money for costly flood control projects;
  3. Minimize the need for rescue and relief efforts associated with flooding and generally undertaken at the expense of the general public;
  4. Minimize prolonged business interruptions;
  5. Minimize damage to public facilities and utilities such as water and gas mains, electric, telephone and sewer lines, streets and bridges located in floodplains;
  6. Help maintain a stable tax base by providing for the sound use and development of flood-prone areas in such a manner as to minimize future flood blight areas; and
  7. Insure that potential buyers are notified that property is in a flood area.

SECTION D. METHODS OF REDUCING FLOOD LOSSES

In order to accomplish its purposes, this ordinance uses the following methods:
  1. Restrict or prohibit uses that are dangerous to health, safety or property in times of flood, or cause excessive increases in flood heights or velocities;
  2. Require that uses vulnerable to floods, including facilities which serve such uses, be protected against flood damage at the time of initial construction;
  3. Control the alteration of natural floodplains, stream channels, and natural protective barriers, which are involved in the accommodation of flood waters;
  4. Control filling, grading, dredging and other development which may increase flood damage;
  5. Prevent or regulate the construction of flood barriers which will unnaturally divert floodwaters or which may increase flood hazards to other lands.

ARTICLE II DEFINITIONS

Unless specifically defined below, words or phrases used in this ordinance shall be interpreted to give them the meaning they have in common usage and to give this ordinance its most reasonable application.

ALLUVIAL FAN FLOODING
Flooding occurring on the surface of an alluvial fan or similar landform which originates at the apex and is characterized by high-velocity flows; active processes of erosion, sediment transport, and deposition; and unpredictable flow paths.
APEX
Point on an alluvial fan or similar landform below which the flow path of the major stream that formed the fan becomes unpredictable and alluvial fan flooding can occur.
AREA OF SHALLOW FLOODING
A designated AO, AH, or VO zone on a community's Flood Insurance Rate Map (FIRM) with a one percent chance or greater annual chance of flooding to an average depth of one to three feet where a clearly defined channel does not exist, where the path of flooding is unpredictable and where velocity flow may be evident. Such flooding is characterized by ponding or sheet flow.
AREA OF SPECIAL FLOOD HAZARD
Land in the floodplain within a community subject to a one percent or greater chance of flooding in any given year. The area may be designated as Zone A on the Flood Hazard Boundary Map (FHBM). After detailed ratemaking has been completed in preparation for publication of the FIRM, Zone A usually is refined into Zones A, AE, AH, AO, A1-99, VO, V1-30, VE or V.
BASE FLOOD
The flood having a one percent chance of being equaled or exceeded in any given year.
BASEMENT
Any area of the building having its floor sub-grade (below ground level) on all sides.
BOARD
Oklahoma Water Resources Board.
CRITICAL FEATURE
An integral and readily identifiable part of a flood protection system, without which the flood protection provided by the entire system would be compromised. DEVELOPMENT - means any man-made change in improved and unimproved real estate, including but not limited to buildings or other structures, mining, dredging, filling, grading, paving, excavation or drilling operations or storage of equipment or materials.
ELEVATED BUILDING
A non-basement building (i) built, in the case of a building in Zones A1-30, AE, A, A99, AO, AH, B, C, X, and D, to have the top of the elevated floor, or in the case of a building in Zones V1-30, VE, or V, to have the bottom of the lowest horizontal structure member of the elevated floor elevated above the ground level by means of pilings, columns (posts and piers), or shear walls parallel to the floor of the water and (ii) adequately anchored so as not to impair the structural integrity of the building during a flood of up to the magnitude of the base flood. In the case of Zones A1-30, AE, A, A99, AO, AH, B, C, X, and D, “elevated building” also includes a building elevated by means of fill or solid foundation perimeter walls with openings sufficient to facilitate the unimpeded movement of flood waters. In the case of Zones V1-30, VE, or V, “elevated building” also includes a building otherwise meeting the definition of “elevated building,” even though the lower area is enclosed by means of breakaway walls if the breakaway walls met the standards of Section 60.3(e)(5) of the National Flood Insurance Program regulations.
EXISTING CONSTRUCTION
For the purposes of determining rates, structures for which the “start of construction” commenced before the effective date of the FIRM or before January 1, 1975, for FIRMs effective before that date. “Existing construction” may also be referred to as “existing structures.”
EXISTING MANUFACTURED HOME PARK OR SUBDIVISION
A manufactured home park or subdivision for which the construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including, at a minimum, the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads) is completed before the effective date of the floodplain management regulations adopted by a community.
EXPANSION TO AN EXISTING MANUFACTURED HOME PARK OR SUBDIVISION
The preparation of additional sites by the construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads).
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 waters. (2)The unusual and rapid accumulation or runoff of surface waters from any source.
FLOOD INSURANCE RATE MAP (FIRM)
An official map of a community, on which the Federal Emergency Management Agency has delineated both the areas of special flood hazards 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, water surface elevation of the base flood, as well as the Flood Boundary-Floodway Map.
FLOODPLAIN OR FLOOD-PRONE AREA
Any land area susceptible to being inundated by water from any source (see definition of flooding).
FLOODPLAIN ADMINISTRATOR
A person accredited by the Board and designated by a floodplain board, to administer and implement laws and regulations relating to the management of the floodplains.
FLOODPLAIN MANAGEMENT
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
Zoning ordinances, subdivision regulations, building codes, health regulations, special purpose ordinances (such as a 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.
FLOOD PROTECTION SYSTEM
Those physical structural works for which funds have been authorized, appropriated, and expended and which have been constructed specifically to modify flooding in order to reduce the extent of the areas within a community subject to a “special flood hazard” and the extent of the depths of associated flooding. Such a system typically includes hurricane tidal barriers, dams, reservoirs, levees or dikes. These specialized flood modifying works are those constructed in conformance with sound engineering standards.
FLOOD PROOFING
Any combination of structural and non-structural 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.
FLOODWAY (REGULATORY FLOODWAY
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 a designated height.
FUNCTIONALLY DEPENDENT USE
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
The highest natural elevation of the ground surface prior to construction next to the proposed walls of a structure.
HISTORIC STRUCTURE
Any structure that is: 1. Listed individually in the National Register of Historic Places (a listing maintained by the Department of Interior) or preliminarily determined by the Secretary of the Interior as meeting the requirements for individual listing on the National Register; 2. Certified or preliminarily determined by the Secretary of the Interior as contributing to the historical significance of a registered historic district or a district preliminarily determined by the Secretary to qualify as a registered historic district; 3. Individually listed on a state inventory of historic places in states with historic preservation programs which have been approved by the Secretary of Interior; or 4. Individually listed on a local inventory or historic places in communities with historic preservation programs that have been certified either: a. By an approved state program as determined by the Secretary of the Interior or; b. Directly by the Secretary of the Interior in states without approved programs.
LEVEE
A man-made structure, usually an earthen embankment, designed and constructed in accordance with sound engineering practices to contain, control, or divert the flow of water so as to provide protection from temporary flooding.
LEVEE SYSTEM
A flood protection system, which consists of a levee, or levees, and associated structures, such as closure, and drainage devices, which are constructed and operated in accordance with sound engineering practices.
LOWEST FLOOR
The lowest floor of the lowest enclosed area (including basement). An unfinished or flood resistant enclosure, usable solely for parking or 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 requirement of Section 60.3 of the National Flood insurance Program regulations.
MANUFACTURED HOME
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. The term “manufactured home” does not include a “recreational vehicle”.
MANUFACTURED HOME PARK OR SUBDIVISION
A parcel (or contiguous parcels) of land divided into two or more manufactured home lots for rent or sale.
MEAN SEA LEVEL
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
For the purpose of determining insurance rates, structures for which the “start of construction” commenced on or after the effective date of an initial FIRM or after December 31, 1974, whichever is later, and includes any subsequent improvements to such structures. For floodplain management purposes, “new construction” means structures for which the “start of construction” commenced on or after the effective date of a floodplain management regulation adopted by a community and includes any subsequent improvements to such structures.
NEW MANUFACTURED HOME PARK OR SUBDIVISION
A manufactured home park or subdivision for which the construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including at a minimum, the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads) is completed on or after the effective date of floodplain management regulations adopted by a community.
REGIONAL FLOOD
A flood that is equal to the 1 % chance flood or the one hundred year flood event. Usually the regional flood is used synonymously as the regulatory flood.
RECREATIONAL VEHICLE
A vehicle which is: 1. Built on a single chassis; 2. 400 square feet or less when measured at the largest horizontal projections; 3. Designed to be self-propelled or permanently towable by a light duty truck; and 4. Designed primarily not for use as a permanent dwelling but as temporary living quarters for recreational, camping, travel, or seasonal use
START OF CONSTRUCTION
(for other than new construction or substantial improvements under the Coastal Barrier Resources Act (Pub. L. 97-348)), includes substantial improvement and means the date the building permit was issued, provided the actual start of construction, repair, reconstruction, rehabilitation, addition, 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 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. For a substantial improvement, the actual start of construction means the first alteration of any wall, ceiling, floor, or other structural part of a building, whether or not that alteration affects the external dimensions of the building.
STRUCTURE
A walled and roofed building, including a gas or liquid storage tank, that is principally above ground, as well as a manufactured home.
SUBSTANTIAL DAMAGE
Damage of any origin sustained by a structure whereby the cost of restoring the structure to its before damaged condition would equal or exceed 50 percent of the market value of the structure before the damage occurred.
SUBSTANTIAL IMPROVEMENT
Any reconstruction, rehabilitation, addition, or other improvement of a structure, the cost of which equals or exceeds 50 percent of the market value of the structure before “start of construction” of the improvement. This includes structures, which have incurred “substantial damage”, regardless of the actual repair work performed. The term does not, however, include either: 1. Any project for improvement of a structure to correct existing violations of state or local health, sanitary, or safety code specifications which have been identified by the local code enforcement official and which are the minimum necessary conditions or 2. Any alteration of a “historic structure” provided that the alteration would not preclude the structure's continued designation as a “historic structure.”
VARIANCE
A grant of relief to a person from the requirement of this ordinance when specific enforcement would result in unnecessary hardship. A variance, therefore, permits construction or development in a manner otherwise prohibited by this ordinance. (For full requirements see Section 60.6 of the National Flood Insurance Program regulations.)
VIOLATION
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 Section 60.3(b)(5), (c)(4), (c)(10), (d)(3), (e)(2), (e)(4), or (e)(5) is presumed to be in violation until such time as that documentation is provided.
WATER SURFACE ELEVATION
The height, in relation to the National Geodetic Vertical Datum (NGVD) of 1929 (or other datum, where specified), of floods of various magnitudes and frequencies in the floodplains of coastal or riverine areas.

ARTICLE III GENERAL PROVISIONS
SECTION A. LANDS TO WHICH THIS ORDINANCE APPLIES
The ordinance shall apply to all areas of special flood hazard within the jurisdiction of (name of community).

SECTION B. 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 (name of community) and Incorporated Areas,” dated (date of map and FIS), with accompanying Flood Insurance Rate Maps (FIRM) are hereby adopted by reference and declared to be a part of this ordinance.

SECTION C. ESTABLISHMENT OF DEVELOPMENT PERMIT
A Development Permit shall be required to ensure conformance with the provisions of this ordinance.

SECTION D. COMPLIANCE
No structure or land shall hereafter be located, altered, or have its use changed without full compliance with the terms of this ordinance and other applicable regulations.

SECTION E. 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.

SECTION F. 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 G. WARNING AND DISCLAIMER OR LIABILITY
The degree of flood protection required by this ordinance is considered reasonable for regulatory purposes and is based on scientific and engineering considerations. On rare occasions greater floods can and will occur and 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 the community or any official or employee thereof for any flood damages that result from reliance on this ordinance or any administrative decision lawfully made thereunder.

ARTICLE IV ADMINISTRATION
SECTION A. DESIGNATION OF THE FLOODPLAIN ADMINISTRATOR
The (name of community official or title) is hereby appointed the Floodplain Administrator to administer and implement the provisions of this ordinance and other appropriate sections of 44 CFR (National Flood Insurance Program Regulations) pertaining to floodplain management.

SECTION B. DUTIES AND RESPONSIBILITIES OF THE FLOODPLAIN ADMINISTRATOR

Duties and responsibilities of the Floodplain Administrator shall include, but not be limited to, the following:
  1. Maintain and hold open for public inspection all records pertaining to the provisions of this ordinance.
  2. Review permit application to determine whether proposed building site, including the placement of manufactured homes, will be reasonably safe from flooding.
  3. Review, approve or deny all applications for development permits required by adoption of this ordinance.
  4. Review permits for proposed development to assure that all necessary permits have been obtained from those Federal, State or local governmental agencies (including Section 404 of the Federal Water Pollution Control Act Amendments of 1972, 33 U.S.C. 1334) from which prior approval are required.
  5. Where interpretation is 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 Floodplain Administrator shall make the necessary interpretation.
  6. Notify, in riverine situations, adjacent communities and the State Coordinating Agency, which is the Oklahoma Water Resources Board, prior to any alteration or relocation of a watercourse, and submit evidence of such notification to the Federal Emergency Management Agency.
  7. Assure that the flood carrying capacity within the altered or relocated portion of any watercourse is maintained.
  8. When base flood elevation data has not been provided in accordance with Article 3, Section B, the Floodplain Administrator shall obtain, review and reasonably utilize any base flood elevation data and floodway data available from a Federal, State or other source, in order to administer the provisions of Article 5.
  9. When a regulatory floodway has not been designated, the Floodplain Administrator must require that no new construction, substantial improvements, or other development (including fill) shall be permitted within Zones A1-30 and AE on the community's FIRM, unless it is demonstrated 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 within the community.
  10. Under the provisions of 44 CFR Chapter 1, Section 65.12, of the National Flood Insurance Program regulations, a community may approve certain development in Zones A1-30, AE, AH, on the community's FIRM which increases the water surface elevation of the base flood by more than one foot, provided that the community first applies for a conditional FIRM revision through FEMA (Conditional Letter of Map Revision).
  11. After a major flood event, fire or other type of disaster that damages one or more residential or non-residential structures determine which structures are substantially damaged.
  12. Become accredited by the Board in accordance with Title 82 O.S. § 1601-1618, as amended.

SECTION C. PERMIT PROCEDURES

Application for a Development Permit shall be presented to the Floodplain Administrator on forms furnished by him/her and may include, but not be limited to, plans in duplicate drawn to scale showing the location, dimensions, and elevation of proposed landscape alterations, existing and proposed structures, including the placement of manufactured homes, and the location of the foregoing in relation to areas of special flood hazard. Additionally, the following information is required:

  1. Elevation (in relation to mean sea level), of the lowest floor (including basement) of all new and substantially improved structures;
  2. Elevation in relation to mean sea level to which any nonresidential structure shall be floodproofed;
  3. A certificate from a registered professional engineer or architect that the nonresidential floodproofed structure shall meet the floodproofing criteria of Article 5, Section B (2);
  4. Description of the extent to which any watercourse or natural drainage will be altered or relocated as a result of proposed development.
  5. Maintain a record of all such information in accordance with Article 4, Section (B)(1). Approval or denial of a Development Permit by the Floodplain Administrator shall be based on all of the provisions of this ordinance and the following relevant factors: (1) The danger to life and property due to flooding or erosion damage; (2) The susceptibility of the proposed facility and its contents to flood damage and the effect of such damage on the individual owner; (3) The danger that materials may be swept onto other lands to the injury of others; (4) The compatibility of the proposed use with existing and anticipated development; (5) The safety of access to the property in times of flood for ordinary and emergency vehicles; (6) The costs of providing governmental services during and after flood conditions including maintenance and repair of streets and bridges, and public utilities and facilities such as sewer, gas, electrical and water systems; (7) 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; (8) The necessity to the facility of a waterfront location, where applicable; (9) The availability of alternative locations, not subject to flooding or erosion damage, for the proposed use; (10) The relationship of the proposed use to the comprehensive plan for that area.

SECTION D. VARIANCE PROCEDURES

  1. The appeal Board as established by the community shall hear and render judgment on requests for variances from the requirements of this ordinance.
  2. The Appeal Board shall hear and render judgment on an appeal only 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.
  3. Any person or persons aggrieved by the decision of the Appeal Board may appeal such decision in the courts of competent jurisdiction.
  4. The Floodplain Administrator shall maintain a record of all actions involving an appeal and shall report variances to the Federal Emergency Management Agency upon request.
  5. 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 ordinance.
  6. 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, providing the relevant factors in Section C (2) of this Article have been fully considered. As the lot size increases beyond the one-half acre, the technical justification required for issuing the variance increases.
  7. Upon consideration of the factors noted above and the intent of this ordinance, the Appeal Board may attach such conditions to the granting of variances as it deems necessary to further the purpose and objectives of this ordinance (Article 1, Section C).
  8. Variances shall not be issued within any designated floodway if any increase in flood levels during the base flood discharge would result.
  9. Variances may be issued for the repair or rehabilitation of historic structures upon a determination that the proposed repair or rehabilitation will not preclude the structure's continued designation as a historic structure and the variance is the minimum necessary to preserve the historic character and design of the structure.
  10. Prerequisites for granting variances: (a) Variances shall only be issued upon a determination that the variance is the minimum necessary, considering the flood hazard, to afford relief.
    (b) Variances shall only be issued upon: (1) Showing a good and 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 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. (c) Any applicant that is issued a variance shall be given written notice that the cost of flood insurance will be commensurate with the increased risk resulting from the lowest floor elevation built with the lowest floor elevation below the base flood elevation.
  11. Variances may be issued by a community for new construction and substantial improvements and for other development necessary for the conduct of a functionally dependent use provided that: (a) The criteria outlined in Article 4, Section D (1)-(9) are met, and (b) 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.
  12. Any person seeking a variance shall file a petition with the local floodplain board, accompanied by a filing fee of at least a minimum of $25.
  13. In no case shall a variance be effective for a period longer than 25 years.
  14. The Floodplain Administrator shall provide a copy of any variance issued to the OWRB within fifteen days of its issuance.

ARTICLE V PROVISIONS FOR FLOOD HAZARD REDUCTION
SECTION A. GENERAL STANDARDS

In all areas of special flood hazards the following provisions are required for all new construction and substantial improvements:

  1. All new construction or substantial improvements shall be designed (or modified) and adequately anchored to prevent flotation, collapse or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy;
  2. All new construction or substantial improvements shall be constructed by methods and practices that minimize flood damage;
  3. All new construction or substantial improvements shall be constructed with materials resistant to flood damage;
  4. All new construction or 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.
  5. All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of flood waters into the system;
  6. New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of flood waters into the system and discharge from the systems into flood waters; and,
  7. On-site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding.

SECTION B. SPECIFIC STANDARDS

In all areas of special flood hazards where base flood elevation data has been provided as set forth in (i) Article 3, Section B, (ii) Article 4, Section B (8), or (iii) Article 5, Section C (3), the following provisions are required:

  1. Residential Construction - new construction and substantial improvement of any residential structure shall have the lowest floor (including basement), elevated to the base flood elevation. A registered professional engineer, architect, or land surveyor shall submit a certification to the Floodplain Administrator that the standard of this subsection as proposed in Article 4, Section C (1) a., is satisfied.
  2. Nonresidential Construction - new construction and substantial improvements of any commercial, industrial or other nonresidential structure shall either have the lowest floor (including basement) elevated to the base flood level or together with attendant utility and sanitary facilities, be designed so that below the base flood level the structure is watertight with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and effects of buoyancy. A registered professional engineer or architect shall develop and/or review structural design, specifications, and plans for the construction, and shall certify that the design and methods of construction are in accordance with accepted standards of practice as outlined in this subsection of such certification. Also, the Floodplain Administrator shall maintain a record of the specific elevation (in relation to mean sea level) to which such structures are floodproofed.
  3. Enclosures - new construction and substantial improvements, with fully enclosed areas below the lowest floor that are usable solely for parking of vehicles, building access or storage in an area other than a basement and which 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) 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. (b) The bottom of all openings shall be no higher than one foot above grade. (c) Openings may be equipped with screens, louvers, valves, or other coverings or devices provided that they permit the automatic entry and exit of floodwaters.
  4. Manufactured Homes—(a) Require that all manufactured homes to be placed within Zone A on a community's FHBM or FIRM shall be installed using methods and practices, which minimize flood damage. For the purposes of this requirement, manufactured homes must be elevated and anchored to resist flotation, collapse, or lateral movement. Methods of anchoring may include, but are not limited to, use of over-the-top or frame ties to ground anchors. This requirement is in addition to applicable State and local anchoring requirements for resisting wind forces.(b) Require that manufactured homes that are placed or substantially improved within Zones A1-30, AH, and AE on the community's FIRM on sites (i) outside of a manufactured home park or subdivision, (ii) in a new manufactured home park or subdivision, (iii) in an expansion to an existing manufactured home park or subdivision, or (iv) in an existing manufactured home park or subdivision on which a manufactured home has incurred “substantial damage” as a result of a flood, be elevated on a permanent foundation such that the lowest floor of the manufactured home is elevated to or above the base flood elevation and be securely anchored to an adequately anchored foundation system to resist flotation, collapse, and lateral movement. (c) Require that manufactured homes be placed or substantially improved on sites in an existing manufactured home park or subdivision with Zones A1-30, AH and AE on the community's FIRM that are not subject to the provisions of paragraph four of this section be elevated so that either: (1) The lowest floor of the manufactured home is at the base flood elevation, or (2) Reinforced piers or other foundation elements of at least equivalent strength that are no less than 36 inches in height above grade and are securely anchored to an adequately anchored foundation system to resist flotation, collapse, and lateral movement support the manufactured home chassis.
  5. Recreational Vehicles—Require that recreational vehicles placed on sites within Zones A1-30, AH, and AE on the community's FIRM either: (a) Be on the site for fewer than 180 consecutive days, (b) Be fully licensed and ready for highway use, or (c) Meet the permit requirements of Article 4, Section C (1), and the elevation and anchoring requirements for “manufactured homes” in paragraph four of this section. A recreational vehicle is ready for highway use if it is on its wheels or jacking system, is attached to the site only by quick disconnect type utilities and security devices, and has no permanently attached additions.

SECTION C. STANDARDS FOR SUBDIVISION PROPOSALS

  1. All subdivision proposals including the placement of manufactured home parks and subdivisions shall be consistent with Article 1, Sections B, C, and D of this ordinance.
  2. All proposals for the development of subdivisions including the placement of manufactured home parks and subdivisions shall meet Development Permit requirements of Article 3, Section C; Article 4, Section C; and the provisions of Article 5 of this ordinance.
  3. Base flood elevation data shall be generated for subdivision proposals and other proposed development including the placement of manufactured home parks and subdivisions which is greater than 50 lots or 5 acres, whichever is lesser, if not otherwise provided pursuant to Article 3, Section B or Article 4, Section B (8) of this ordinance.
  4. All subdivision proposals including the placement of manufactured home parks and subdivisions shall have adequate drainage provided to reduce exposure to flood hazards.
  5. All subdivision proposals including the placement of manufactured home parks and subdivisions shall have public utilities and facilities such as sewer, gas, electrical and water systems located and constructed to minimize or eliminate flood damage.

SECTION D. STANDARDS FOR AREAS OF SHALLOW FLOODING (AO/AH ZONES)

Located within the areas of special flood hazard established in Article 3, Section B, 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 where velocity flows may be evident. Such flooding is characterized by ponding or sheet flow; therefore, the following provisions apply:

  1. All new construction and substantial improvements of residential structures 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 community's FIRM (at least two feet if no depth number is specified).
  2. All new construction and substantial improvements of non-residential structures; (a) 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 community's FIRM (at least two feet if no depth number is specified), or; (b) Together with attendant utility and sanitary facilities be designed so that below the base flood level the structure is watertight with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads of effects of buoyancy.
  3. A registered professional engineer or architect shall submit a certification to the Floodplain Administrator that the standards of this Section, as proposed in Article 4, Section C (1) a., are satisfied.
  4. Require within Zones AH or AO adequate drainage paths around structures on slopes, to guide floodwaters around and away from proposed structures.

SECTION E. FLOODWAYS

Floodways located within areas of special flood hazard established in Article 3, Section B, are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of floodwaters, which carry debris, potential projectiles and erosion potential, the following provisions shall apply:

  1. Encroachments are prohibited, including fill, new construction, substantial improvements and other development within the adopted regulatory floodway unless it has been demonstrated through hydrologic and hydraulic analyses performed in accordance with standard engineering practice that the proposed encroachment would not result in any increase in flood levels within the community during the occurrence of the base flood discharge.
  2. If Article 5, Section E (1) above is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of Article 5.
  3. Under the provisions of 44 CFR Chapter 1, Section 65.12, of the National Flood Insurance Regulations, a community may permit encroachments within the adopted regulatory floodway that would result in an increase in base flood elevations, provided that the community first applies for a conditional FIRM and floodway revision through FEMA.

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 and other applicable regulations. Violation of the provisions of this ordinance by failure to comply with any of its requirements (including violations of conditions and safeguards established in connection with conditions) 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 $ __________or imprisoned for not more than _____days, or both, for each violation, and in addition shall pay all costs and expenses involved in the case. Nothing herein contained shall prevent the (name of community goes here ) from taking such other lawful action as is necessary to prevent or remedy any violation.

CERTIFICATION

It is hereby found and declared by (name of community goes here) that severe flooding has occurred in the past within its jurisdiction and will certainly occur within the future; that flooding is likely to result in infliction of serious personal injury or death, and is likely to result in substantial injury or destruction of property within its jurisdiction; in order to effectively comply with minimum standards for coverage under the National Flood Insurance Program; and in order to effectively remedy the situation described herein, it is necessary that this ordinance become effective immediately. Therefore, an emergency is hereby declared to exist, and this ordinance, being necessary for the immediate preservation of the public peace, health and safety, shall be in full force and effect from and after its passage and approval.

APPROVED; ________________________________________________ (Community official)

PASSED: _____________________________ (Date) I, the undersigned,

__________________________________, do hereby certify that the above is a true and correct

copy of an ordinance duly adopted by _________, at a regular meeting duly convened on

__________________________. (Date)

__________________________________________________ (Secretary or responsible person) (SEAL) For your information regarding the penalty clause, the penalty clause was inserted in the ordinance above in accordance with Section 59.2(b) of CFR 44, Chapter 1, of the National Flood Insurance Program (NFIP) regulation, to qualify for the sale of federally-subsidized flood insurance, a community must adopt floodplain management regulations that meet or exceed the minimum standards of Section 60. “These regulations must include effective enforcement provisions.” In accordance with Section 60.1(b) of CFR 44, Chapter 1, of the NFIP regulations, “These regulations must be legally-enforceable, applied uniformly throughout the community to all privately and publicly owned land within flood-prone (i.e. mudflow) or flood-related erosion areas, and the community must provide that the regulations take precedence over less restrictive conflicting local laws, ordinances or codes.” The penalty clause that has been inserted in this ordinance should be modified as necessary to reflect the city, town or county and State of Oklahoma statutory provisions.

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Appendix 3-2: Flood Ordinance Evaluation

What are the minimum requirements for your local community to participate in the National Flood Insurance Program?

Requirements are based on the Special Flood Hazard Area Mapping in your community. Determine what level of flood ordinance (minimum requirements) your community will need the following. The requirements are accumulative in nature and requirements listed in 60.3(a) are also required in 60.3(b), 60.3(c) also includes 60.3(a) and (b), and 60.3(d) also includes 60.3(a), (b), and (c).

Read the following explanation and decide which requirements meet your local community.

60.3(a) Applies to communities where Special Flood Hazard Areas have not yet been defined by FEMA. The community may apply and participate in the NFIP if it agrees to development permits, other federal and state permits, review of permit applications, review of subdivision proposals, minimize water system infiltration and prevent sewage system contamination or impairment.

60.3(b) Applies to communities where FEMA has provided a Flood Hazard Boundary Map (FHBM) or Flood Insurance Rate Map (FIRM) that identifies special flood hazard areas (A Zones), but has not provided base flood elevation (BFE) data or identified a floodway.

60.3(c) Applies to communities where FEMA has provided final flood elevations (BFE) for one or more special flood hazard areas of the community's FIRM, but has not identified a regulatory floodway.

60.3(d) Applies to communities where FEMA has provided the final base flood elevations (BFE) within zones A1-30 and/or AE on the FIRM, and has provided information to designate a regulatory floodway.

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Appendix 3-3: Local Floodplain Management Program Guidelines

The primary objectives of an effective local floodplain management program are (1) the mitigation of flood damage to real and personal property, and (2) the reduction of risk to human lives from floodwaters. These objectives can be accomplished through the implementation and enforcement of local floodplain management regulations designed to reduce flooding risks.

The National Flood Insurance Program (NFIP) was created to make available flood insurance coverage to communities who choose to adopt and agree to enforce an effective local floodplain management program. The NFIP regulations at 44 CFR 60.3 establish minimum floodplain management requirements which, if adopted, will enable community participation in the Program and serve as the basis for an effective local floodplain management program.

  1. The NFIP minimum requirements are designed to reduce flooding risks and are based in part on the following criteria:
  2. The community must have an adopted and enforceable floodplain management ordinance that meets or exceeds the minimum requirements of the NFIP.
  3. There must be an individual who is assigned floodplain management responsibilities or coordination of the community's floodplain management program.
  4. The community must have a development permit application process that will do the following: (1) Assist the community with the early identification of proposed activities that meet the NFIP definition of development; (2) Allow for-identification of the flood status or flood zone for the property on which the development is proposed; (3) Result in advising the property owner, developer and/or other individuals of any floodplain management requirements that may apply to the property and the proposed development within the special flood hazard area (SFHs), including as appropriate: (a) lowest floor elevation requirements; (b) requirements for breakaway walls (V-Zone); (c) hyrdrostatic equalization requirements; (d) certification that the pile or column foundation and structure attached there to is anchored to resist flotation, collapse, and lateral movement; (e) prohibition of man-made alterations of sand dunes; (f) substantial improvement permit requirements; (g) the need for review, permits and/or approval of other federal or state agencies; (h) floodway encroachment restrictions and data needs; (i) the design and installation of water supply and sanitary sewage systems; (j) certification requirements for floodproofing of nonresidential structures; and (k) requirement to elevate mechanical and utility equipment. (4) Assure the community that development which is permitted within the identified SFHA will be in compliance with minimum NFIP requirements and requirements of its local ordinance.
  5. The community must maintain a file with specific information on all development that takes place within the SFHA.
  6. The community must have a system or process for periodic field survey of the SFHA to (1) assure that permitted development is being carried out in a compliant manner, (2) detect unpermitted development, and (3) assure continued compliance of permitted and compliant development.
  7. When a comprehensive plan exists, the plan and floodplain management objectives must be consistent. A community shall assure that when a comprehensive plan exists, the floodplain management objectives are consistent.
  8. The community must notify adjacent communities of proposed development that may impact areas outside their jurisdictional boundaries.
  9. The community must require that existing floodplain-related data be identified on subdivisions of 50 lots or five acres, whichever is smaller, before they are approved. This should include the 100-year flood boundaries, floodway boundaries (if established), velocity zones (if appropriate), required elevations and other necessary floodplain management data.
  10. Communities should also be concerned with: (1) The improvement of local drainage to control increased runoff that might increase the danger of flooding to other properties; (2) State regulations and Executive Orders; (3) Flood warning and emergency preparedness planning; (4) The provision for alternative routes when normal routes are blocked or destroyed by flooding; and (5) The establishment of minimum floodproofing and access requirements for critical facilities, such as schools, hospitals, nursing homes, orphanages, penal institutions, fire stations, police station communications centers, water and -sewerage pumping stations and other public or quasi-public facilities already located in the flood-prone area, to enable them to withstand flood damage and to facilitate emergency operations.

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Appendix 3-4: Elevation Certificate

Click to download form from FEMA

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Appendix 3-5: Floodproofing Certificate for Non-Residential Structures

Click to download form from FEMA

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Appendix 3-6: The Lowest Floor

One of the most critical performance standards found in the National Flood Insurance Program (NFIP) regulations is to flood protect structures to or above the 100-year (base flood) elevation. Section 60.3(c)(2) of the NFIP regulations states that the lowest floor of a residential structure must be elevated to or above the 100-year flood elevation. Section 60.3(c)(3) adds that nonresidential or commercial structures can be either elevated or dry floodproofed to or above the 100-year flood elevation. The remainder of this article focuses on elevating structures; dry floodproofing may be an option for nonresidential structures.

Although the term “first floor” is commonly used, it has no place in a community's floodplain management program. NFIP standards and your community floodplain management regulations use the term lowest floor. As defined in the NFIP regulations, the lowest floor is: 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 built in accordance with the applicable design requirements specified in this ordinance for enclosures below the lowest floor.
A lowest floor may be the concrete slab when the structure has a “slab-on-grade” foundation, it may be the basement floor when the structure has a basement, or it may be the first floor when the structure is built on an enclosed area such as a crawl space.

Recall that the definition of the lowest floor of a structure includes the “basement” floor. So, basement must be defined. The NFIP regulations define a basement as: any area of a building having its floor subgrade (below ground level) on all sides.

Of course, this definition includes buildings with standard 8-10 foot deep basements. However, the definition is also inclusive of any enclosed area in which the interior grade is lower than the exterior grade of the enclosed area on all sides. This is extremely important to local floodplain permitting officials since any enclosure defined as a “basement” must have its “basement” floor elevated to or above the 100-year flood elevation.

The final term that must be defined is that of an enclosure below the lowest floor. It is found within the definition of lowest floor:
... 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 built in accordance with the applicable design requirements specified in this ordinance for enclosures below the lowest floor.

Three requirements are given here. First, the only uses recognized for an enclosure below the lowest floor are parking, building access and storage. In other words, enclosures below the lowest floor are not meant to be finished and certainly not to be used as living space. Second, enclosures below the lowest floor must not fall under the definition of a basement. For example, backfilling around the enclosed area could make it a basement if the grade on all sides of a structure outside of the enclosed area is higher than the grade inside the enclosed area. Finally, enclosures below the lowest floor must be designed to equalize the flood forces on the enclosure. The design requirements are found in community floodplain regulations under “Specific Standards”.

A crawl space is not specifically defined in a community's floodplain regulations. If the local floodplain administrator receives a Special Flood Hazard Area Development (SFHA) permit application, it should be carefully evaluated with plans showing a structure built on a crawl space. There have been several instances throughout the state where an applicant has proposed a structure with a crawl space and the local floodplain official allowed the development to proceed without applying any design or elevation standards. Once the structure was built, and flood insurance was required, the homeowner discovered that flood insurance was very expensive. Why? Because the enclosed area, initially called a crawl space, was actually a basement according to the community's floodplain regulations and flood insurance rating criteria.

Many communities have building and zoning codes in addition to their floodplain regulations. Each code may have a slightly different definition of basements, first floor, lowest floor, crawl space, etc. When a structural development is proposed in an identified SFHA, the development must be evaluated against the criteria found in the community's floodplain regulations. In doing so, terms such as “first floor” and “crawl space” have no relevance. Local floodplain officials should be thinking in terms of lowest floor, basement, and enclosures below the lowest floor.

Oklahoma's Floodplain Management, 2nd Ed. -23- OKLAHOMA WATER RESOURCES BOARD

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