Section 29-22 District F-1, floodplain overlay district.

(a) Authority, findings of fact and purposes.

(1) Authority. The city council of the City of Columbia, Missouri enacts these floodplain management regulations under its authority to adopt zoning regulations designed to protect the health, safety and general welfare which authority was granted to the City of Columbia as a home rule charter city by the people of the State of Missouri in Article VI, Section 19(a) of the Missouri Constitution and by the General Assembly of the State of Missouri in Chapter 89 of the Missouri Revised Statutes.

(2) Findings of fact.

a. Flood losses resulting from periodic inundation. The flood hazard areas of Columbia, Missouri, are subject to 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. General causes of these flood losses. These flood losses are caused by (1) The cumulative effect of obstructions in floodways causing increases in flood heights and velocities, (2) The occupancy of flood hazard areas by uses vulnerable to floods or hazardous to others, which are inadequately elevated or otherwise unprotected from flood damages.

c. Methods used to analyze flood hazards. This section uses a reasonable method of analyzing flood hazards which consists of the following series of interrelated steps:

1. Selection of regulatory flood which is based upon engineering calculations which permit a consideration of such flood factors as its expected frequency of occurrence, the area inundated, and the depth of inundation. The regulatory flood selected for this section is representative of large floods which are reasonably characteristic of what can be expected to occur on the particular streams subject to this section. It is in the general order of a flood which could be expected to have a one (1) per cent chance of occurrence in any one (1) year, as delineated by the Federal Insurance Administration's Flood Insurance Study, and illustrative materials dated March 17, 2011, as amended, and any future revisions thereto.

2. Calculation of water surface profiles based on a hydraulic engineering analysis of the capacity of the stream channel and overbank areas to convey the regulatory flood.

3. Computation of the floodway required to convey this flood without increasing flood heights more than one (1) foot at any point.

4. Delineation of floodway encroachment lines within which no obstruction is permitted which would cause any increase in flood height.

5. Delineation of flood fringe, i.e., that area outside the floodway encroachment lines but which still is subject to inundation by the regulatory flood.

(3) Purpose. The purpose of the floodplain overlay district is to promote the public health, safety, and general welfare and to minimize those losses described in subsection (a)(2)a. to establish or maintain the community's eligibility for participation in the National Flood Insurance Program (NFIP) as defined in 44 Code of Federal Regulations 59.22(a)(3), and to meet the requirements of 44 CFR 60.3(d) by applying the provisions of this section to:

a. Restrict or prohibit uses that are dangerous to health, safety, or property in times of flooding or cause undue increases in flood heights or velocities.

b. Require that uses vulnerable to floods, including public facilities which serve such uses, be provided with flood protection at the time of initial construction.

c. Protect individuals from buying lands that are unsuited for intended purposes because of flood hazard.

(b) General provisions.

(1) Lands to which ordinance applies. This section shall apply to all lands within the jurisdiction of the City of Columbia identified on the flood insurance rate map (FIRM) for Boone County, Missouri on map panels 29019C0165D, 29019C0170D, 29019C0190D, 29019C0260D, 29019C270D, 29019C0280D, 29019C0285D, 29019C0290D, 29019C0295D, 29019C0325D, 29019C0335D and 29019C0355D as A zones (including AE, AO and AH zones) dated March 17, 2011 as amended and any future revisions thereto, and that portion of the X zone shaded, other flood areas, which is in the upper square mile of a flood drainage area. In all areas covered by this section, no development shall be permitted except upon the issuance of a floodplain permit to develop granted by the director of public works under such safeguards and restriction as the director of public works may reasonably impose for the promotion and maintenance of the general welfare and health of the inhabitants of the community and where specifically noted in this section.

(2) The enforcement officer. The director of public works is hereby designated as the duly designated Local Floodplain Administrator under this section.

(3) Rules for interpretation of district boundaries. The boundaries of the floodway, flood fringe, and flood drainage area shall be determined by scaling distances on the official zoning map or on the flood insurance rate map or floodway map. Where interpretation is needed to the exact location of the boundaries of the district as shown on the official zoning map, as for example where there appears to be a conflict between a mapped boundary and actual field conditions, the director of public works shall make the necessary interpretation. In such cases where the interpretation is contested, the board of adjustment will resolve the dispute. The regulatory flood elevation for the point in question shall be the governing factor in locating the district boundary on the land. The person contesting the location of the district boundary shall be given a reasonable opportunity to present his case to the board and to submit his own technical evidence, if he so desires.

(4) Compliance. No development within known flood hazard areas of the City of Columbia shall be located, extended, converted or structurally altered without full compliance with the terms of this section and other applicable regulations.

(5) Abrogation and greater restrictions. It is not intended by this section to repeal, abrogate or impair any existent easements, covenants, or deed restrictions. However, where this section imposes greater restrictions, the provisions of this section shall prevail. All other ordinances inconsistent with this section are hereby repealed to the extent of the inconsistency only.

(6) Interpretation. In their interpretation and application, the provisions of this section shall be held to be minimum requirements and shall be liberally construed in favor of the city council and shall not be deemed a limitation or repeal of any other powers granted by state statutes.

(7) Warning and disclaimer of liability. The degree of flood protection required by this section is considered reasonable for regulatory purposes and is based on engineering and scientific methods of study. Larger floods may occur on rare occasions or the flood height may be increased by manmade or natural causes, such as ice jams and bridge openings restricted by debris. This section does not imply that areas outside of the floodway, flood fringe, and flood drainage area boundaries or land uses permitted within such areas will be free from flooding or flood damage. This section shall not create liability on the part of the City of Columbia or any officer or employee thereof for any flood damages that may result from reliance on this section or any administrative decision lawfully made thereunder.

(8) Severability. If any subsection, clause, provision or portion of this section is adjudged unconstitutional or invalid by a court of competent jurisdiction, the remainder of this section shall not be affected thereby.

(9) Appeal. Where a request for a floodplain development permit to develop or for a variance is denied by the director of public works the applicant may apply for such floodplain development permit or variance to these regulations directly to the board of adjustment.

(1) Permit required. No person, firm or corporation shall initiate any development or substantial improvement or cause the same to be done without first obtaining a separate floodplain development permit for development as defined in subsection (h).

(2) Administration.

a. The director of public works is hereby appointed to administer and implement the provisions of this section.

b. Duties of the director of public works shall include, but not be limited to:

1. Review all applications for floodplain development permits to assure that sites are reasonably safe from flooding and that the floodplain development permit requirements of this section have been satisfied.

2. Review all applications for floodplain development permits for proposed development to assure that all necessary permits have been obtained from those federal, state or local governmental agencies from which prior approval is required.

3. Issue floodplain development permits for approved applications.

4. Notify adjacent communities, the State of Missouri Emergency Management Agency, the Missouri Clean Water Commission, and the Department of Natural Resources prior to any alteration or relocation of a watercourse, and shall submit evidence of such notification to the Federal Emergency Management Agency.

5. Assure that maintenance is provided within the altered or relocated portion of said watercourse so that the flood carrying capacity is not diminished.

6. Verify, record and maintain record of the actual elevation (in relation to mean sea level) of the lowest floor (including basement) of all new or substantially improved structures.

7. Verify, record and maintain record of the actual elevation (in relation to mean sea level) to which the new or substantially improved non-residential structures have been floodproofed.

8. When floodproofing is utilized for a particular non-residential structure, the director of public works shall be presented certification from a registered professional engineer or architect.

(3) Application for permit. To obtain a floodplain development permit, the applicant shall first file an application in writing on a form furnished for that purpose. Every such application shall:

a. Identify and describe the work to be covered by the floodplain development permit.

b. Describe the land on which the proposed work is to be done by lot, block tract and house and street address, or similar description that will readily identify and definitely locate the proposed building or work.

c. Indicate the use or occupancy for which the proposed work is intended.

d. Be accompanied by plans and specifications for proposed construction.

e. Be signed by the permittee or his authorized agent who may be required to submit evidence to indicate such authority.

f. Give such other information as reasonably may be required by the director of public works.

(d) Provisions for flood hazard reduction.

(1) General standards.

a. No permit for development shall be granted for new construction, substantial improvements and other improvements including the placement of manufactured homes within all numbered and unnumbered A zones (including AE, AO and AH zones) and that portion of the X zone shaded, other flood areas, which is in the upper square mile of a flood drainage area, unless the conditions of this subsection are satisfied.

b. All areas identified as unnumbered A zones and X zones shaded, other flood areas, on the FIRM are subject to inundation of the 1% annual chance flood; however, the water surface elevation was not provided. The unnumbered A zones shall be subject to all development provisions of this section. If flood insurance study data is not available, the community shall utilize any base flood elevation or floodway data currently available from federal, state or other sources.

c. New construction, subdivision proposals, substantial improvements, prefabricated buildings, placement of manufactured homes and other developments shall require:

1. Design or anchorage to prevent flotation, collapse or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy.

2. New or replacement water supply systems and sanitary sewage systems be designed to minimize or eliminate infiltration of flood waters into the systems and discharges from the systems into flood waters, and onsite waste disposal systems be located so as to avoid impairment or contamination.

3. Construction with materials resistant to flood damage, utilizing methods and practices that minimize flood damage, and with electrical, heating, ventilation, plumbing, and air conditioning equipment and other service facilities that are designed or located so as to prevent water from entering or accumulating within the components during conditions of flooding.

4. All utility and sanitary facilities be elevated or floodproofed up to the regulatory flood protection elevation.

5. That until a floodway has been designated, no development, including landfill, may be permitted within Zone AE and the flood drainage area (Zone X shaded, other flood areas - upper square mile) on the city's FIRM unless the applicant for the land use has demonstrated that the proposed use, when combined with all other existing and reasonably anticipated uses, will not increase the water surface elevation of the 1% annual chance flood more than one (1) foot on the average cross section of the reach in which the development or landfill is located as shown on the flood insurance rate study incorporated by reference: subsection (a)(2)c.1. of this section.

6. Storage of material and equipment:

a. The storage or processing of materials that are in time of flooding buoyant, flammable, explosive, or could be injurious to human, animal or plant life is prohibited.

b. Storage of other material or equipment may be allowed if not subject to major damage by floods and firmly anchored to prevent flotation or if readily removable from the area within the time available after flood warning.

7. Subdivision proposals and other proposed new development, including manufactured home parks or subdivisions, be required to assure that (1) all such proposals are consistent with the need to minimize flood damage, (2) all public utilities and facilities, such as sewer, gas, electrical, and water systems are located, elevated and constructed to minimize or eliminate flood damage, (3) adequate drainage is provided so as to reduce exposure to flood hazards, and (4) proposals for development (including proposals for manufactured home parks) of five (5) acres or fifty (50) lots, whichever is lesser, include within such proposals the regulatory flood elevation.

(2) Specific standards. In all areas of special flood hazard where base flood elevation data have been provided as set forth in subsection (a)(2)c., the following provisions are required:

a. Residential construction. New construction or substantial improvements of any residential building or manufactured home shall have the lowest floor, including basement, elevated to at least two (2) feet above base flood elevation. Should solid foundation perimeter walls be used to elevate a structure, openings sufficient to facilitate the unimpeded movements of floodwaters shall be provided in accordance with standards of subsection (d)(2)c.

b. Nonresidential construction. New construction or substantial improvements of any commercial, industrial, or nonresidential building or manufactured home shall have the lowest floor, including basement, elevated to at least two (2) feet above base flood elevation. Buildings located in all A-zones may be floodproofed in lieu of being elevated provided that all areas of the building below the required elevation are watertight with walls substantially impermeable to the passage of water and use structural components having the capability of resisting hydrostatic and hydrodynamic loads and the effect of buoyancy. A registered professional engineer or architect shall certify that the standards of this subsection are satisfied. Such certification shall be provided to the official as set forth in subsection (c)(2)b.7.

c. Elevated buildings. New construction or substantial improvements of elevated buildings that include fully enclosed areas formed by foundation and other exterior walls below the base flood elevation shall be designed to preclude finished living space and designed to allow for the entry and exit of floodwaters to automatically equalize hydrostatic flood forces on exterior walls.

1. Designs for complying with this requirement must either be certified by a professional engineer or architect or meet the following minimum criteria:

a. Provide a minimum of two (2) openings having a total net area of not less than one square inch for every square foot enclosed area subject to flooding;

b. The bottom of all openings shall be no higher than one foot above grade; and

c. Openings may be equipped with screens, louvers, valves, or other coverings or devices provided they permit the automatic flow of floodwaters in both directions.

2. Access to the enclosed area shall be the minimum necessary to allow for parking of vehicles (garage door) or limited storage of maintenance equipment used on connection with the premises (standard exterior door) or entry to the living area (stairways or elevator); and

3. The interior portion of such enclosed area shall not be partitioned or finished into separate rooms.

(3) AH zones. Within AH zones adequate drainage paths around structures on slopes shall be required in order to guide floodwaters around and away from proposed structures.

(4) Manufactured homes.

a. All manufactured homes shall be anchored to resist flotation, collapse, or lateral movement. Manufactured homes must be anchored in accordance with local building codes or FEMA guidelines. In the event that over-the-top frame ties to ground anchors are used, the following specific requirements (or their equivalent) shall be met:

Over-the-top ties be provided at each of the four (4) corners of the manufactured home, with two (2) additional ties per side at intermediate locations and manufactured homes less than fifty (50) feet long requiring one additional tie per side;

Frame ties be provided at each corner of the home with five (5) additional ties per side at intermediate points and manufactured homes less than fifty (50) feet long requiring four (4) additional ties per side;

All components of the anchoring system be capable of carrying a force of four thousand eight hundred (4,800) pounds; and

Any additions to the manufactured home be similarly anchored.

b. All manufactured homes to be placed within Zones AH, AE and X shaded, other flood areas, on Columbia's FIRM on sites:

1. outside of a manufactured home park or subdivision,

2. in a new manufactured home park or subdivision,

3. in an expansion to an existing manufactured home park or subdivision, or

4. in an existing manufactured home park or subdivision on which a manufactured home has incurred "substantial damage" as a result of a flood,

shall be elevated on a permanent foundation such that the lowest floor of the manufactured home is at least two (2) feet above the base flood elevation; and shall be securely anchored to an adequately anchored foundation system in accordance with the provisions of subsection (d)(4)a.

c. Manufactured homes to be placed or substantially improved on sites in an existing manufactured home park or subdivision within Zones AH, AE and X shaded, other flood areas, on Columbia's FIRM that are not subject to the provisions of subsection (d)(4)a. shall be elevated so that either:

1. The lowest floor of the manufactured home is at least two (2) feet above the base flood elevation, or

2. The manufactured home chassis is supported by reinforced piers or other foundation elements of at least equivalent strength that are no less than thirty-six (36) inches in height above grade and are securely anchored to an adequately anchored foundation system in accordance with the provisions of subsection (d)(4)a.

(5) Recreational vehicles. All recreational vehicles placed on sites within the identified floodplain on Columbia's FIRM shall either be on the site for fewer than one hundred eighty (180) consecutive days, and be fully licensed and ready for highway use or meet the permit requirements and the elevation and anchoring requirements for manufactured homes of this section. A recreational vehicle is ready for highway use if it is on its wheels or its jacking system, is attached to the site only by quick disconnect type utilities and security devices and it has no permanently attached additions.

(6) AO zones. Located within the areas of special flood hazard established in section (b)(1) are areas designed as AO zones. These areas have special flood hazards associated with base flood depths of one (1) to three (3) feet where a clearly defined channel does not exist and where the path of flooding is unpredictable and indeterminate; therefore, the following provisions apply within AO Zones:

a. 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 two (2) feet above the depth number specified in feet on Columbia's FIRM (at least three (3) feet if no depth number is specified).

b. All new construction and substantial improvements of nonresidential structures shall:

Have the lowest floor (including basement) elevated above the highest adjacent grade at least as high as two (2) feet above the depth number specified in feet on Columbia's FIRM (at least three (3) feet if no depth number is specified), or

Together with attendant utility and sanitary facilities be completely floodproofed to or above that level so that any space below that level is watertight with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and effects of buoyancy. Such certification shall be provided to the official as set forth in subsection (c)(2)b.7.

c. Adequate drainage paths around structures on slopes shall be required in order to guide floodwaters around and away from proposed structures.

(7) Floodway overlay district.

a. Permitted uses. Only uses having a low flood-damage potential and not obstructing flood flows shall be permitted within the floodway district to the extent that they are not prohibited by any other ordinance. All encroachments, including fill, new construction, substantial improvements and other developments must be prohibited unless a “no-rise” certification statement by a professional registered engineer or architect is provided . A “no-rise” certification statement shall be accompanied by supporting documentation which shall adequately demonstrate that encroachments shall not result in any increase in flood levels during occurrence of the base flood discharge. No use shall increase the flood levels of the regulatory flood elevation. These uses are subject to the standards of subsection (d). The following are recommended uses for the floodway district.

1. Agricultural uses such as general farming, pasture, nurseries, forestry.

2. Residential uses such as lawns, gardens, parking and play areas.

3. Nonresidential areas such as loading areas, parking and airport landing strips.

4. Public and private recreational uses such as golf courses, archery ranges, picnic grounds, parks, wildlife and nature preserves.

b. In Zone A unnumbered, obtain, review and reasonably utilize any floodway data available through Federal, State or other sources or section (d)(1)c.7. of this section, in meeting the standards of this subsection.

(e) Variance procedures.

(1) The board of adjustment shall hear and decide appeals and requests for variances from the requirements of this section.

(2) The board shall hear and decide appeals when it is alleged that there is an error in any requirement, decision, or determination made by the director of public works in the enforcement or administration of this section.

(3) Any person aggrieved by the decision of the board or any taxpayer may appeal such decision to the circuit court of Boone County.

(4) In passing upon such applications, the board shall consider all technical evaluation, all relevant factors, standards specified in other subsections of this section, and:

a. The danger that materials may be swept onto other lands to the injury of others;

b. The danger to life and property due to flooding or erosion damage;

c. The susceptibility of proposed facility and its contents to flood damage and the effect of such damage on the individual owner;

d. The importance of the services provided by the proposed facility to the community;

e. The necessity to the facility of a waterfront location, where applicable;

f. The availability of alternative locations, not subject to flooding or erosion damage, for the proposed use;

g. The compatibility of the proposed use with existing and anticipated development;

h. The relationship of the proposed use to the comprehensive plan and flood plain management program for that area;

i. The safety of access to the property in times of flood for ordinary and emergency vehicles;

j. The expected heights, velocity, duration, rate of rise and sediment transport of the flood waters and the effects of wave action, if applicable, expected at the site; and,

k. The costs of providing governmental services during and after flood conditions including maintenance and repair of public utilities and facilities such as sewer, gas, electrical, and water systems, and streets and bridges.

(5) Conditions for variances.

a. 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, providing items b. through f. below have been fully considered. As the lot size increases beyond the one-half acre, the technical justification required for issuing the variance increases.

b. 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 subsection.

c. Variances shall not be issued within any designated floodway if any increase in flood levels during the base flood discharge would result.

d. Variances shall only be issued upon a determination that the variance is the minimum necessary, considering the flood hazard, to afford relief.

e. 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 (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.

f. Any applicant to whom a variance is granted shall be given a written notice that the cost of flood insurance will be commensurate with the increased risk resulting from the reduced lowest floor elevation.

(f) Penalties for violation. Violation of the provisions of this section or failure to comply with any of its requirements (including violations of conditions and safeguards established in connection with grants of variances or special exceptions) shall constitute a misdemeanor. Any person who violates this section or fails to comply with any of its requirements shall upon conviction thereof be fined not more than one thousand dollars ($1,000.00) and, in addition, shall pay all costs and expenses involved in the case. Each day such violation continues shall be considered a separate offense. Nothing herein contained shall prevent the City of Columbia or other appropriate authority from taking such other lawful action as is necessary to prevent or remedy any violation.

(g) Amendments. The regulations, restrictions, and boundaries set forth in this section may from time to time be amended, supplemented, changed or repealed to reflect any and all changes in the National Flood Disaster Protection Act of 1973, provided, however, that no such action may be taken until after a public hearing in relation thereto, at which parties in interest and citizens shall have an opportunity to be heard. Notice of the time and place of such hearing shall be published in a newspaper of general circulation in the city of Columbia. At least fifteen (15) days shall elapse between the date of this publication and the public hearing. A copy of such amendments will be provided to the Region VII of the Federal Emergency Management Agency. The regulations of this section are in compliance with the National Flood Insurance Program regulations.

(h) Definitions. Unless specifically defined below, words or phrases used in this section shall be interpreted so as to give them the meaning they have in common usage and to give this section its most reasonable application. These definitions are for the purpose of this section only and may differ from those in section 29-2.

1% annual chance flood (100-year flood) see "base flood."

Accessory structure means the same as appurtenant structure.

Actuarial or risk premium rates means those rates established by the administrator of the National Flood Insurance Program pursuant to individual community studies and investigations which are undertaken to provide flood insurance in accordance with section 1307 of the act and the accepted actuarial principles. "Risk premium rates" include provisions for operating costs and allowances.

Administrator means the Federal Insurance Administrator.

Agency means the Federal Emergency Management Agency.

Agricultural commodities means agricultural commodities and livestock.

Agricultural structure means any structure used exclusively in connection with the production, harvesting, storage, raising or drying of agricultural commodities.

Appeal means a request for a review of the interpretation of the director of public works of any provision of this section or a request for a variance.

Appurtenant structure means a structure which is on the same parcel of property as the principal structure to be insured and the use of which is incidental to the use of the principal structure.

Area of shallow flooding means a designated AO or AH zone on the flood insurance rate map (FIRM) with a one (1) percent or greater annual chance of flooding to an average depth of one (1) to three (3) feet where a clearly defined channel is unpredictable and where velocity flow may be evident. Such flooding is characterized by ponding or sheet flow.

Area of special flood hazard is the land in the floodplain subject to one (1) percent or greater chance of flooding in any given year.

Base flood means the flood having one (1) percent chance of being equalled or exceeded in any given year.

Basement means any area of the building having its floor subgrade (below ground level) on all sides.

Building. See "structure."

Chief executive officer or chief elected official means the official of the community who is charged with the authority to implement and administer laws, ordinances and regulations for that community.

Development means any manmade change to improved or unimproved real estate, including but not limited to buildings or other structures, levees, levee systems, mining, dredging, filling, grading, paving, excavation or drilling operations, or storage of equipment or materials.

Elevated building means a non-basement building:

(1) built, in the case of a building in Zones AE, A, A99, AO, AH, X shaded, other flood areas, X un-shaded, other areas, or D to have the top of the elevated floor, elevated above the ground level by means of pilings, columns (posts and piers), or shear walls parallel to the flow of water, and

(2) 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.

This 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.

Eligible community or participating community means a community for which the administrator has authorized the sale of flood insurance under the National Flood Insurance Program.

Existing construction means (for the purposes of determining rates) structures for which the "start of construction" commenced before the effective date of the FIRM. "Existing construction" may also be referred to as "existing structures."

Existing manufactured home park or subdivision means 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) was complete before October 1, 1973.

Expansion to an existing manufactured home park or subdivision means 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 means a general and temporary condition of partial or complete inundation of normally dry land areas from:

(1) The overflow of a stream.

(2) The unusual and rapid accumulation of runoff of surface waters from any source.

Flood drainage areas (less than one square mile). Areas designated within the 1% annual chance floodplain by the December 1, 1981 flood insurance study, but containing a drainage area less than one square mile. The December 1, 1981 flood insurance study did not establish the base flood elevation or delineate the floodway and flood fringe for these areas; rather the base flood elevation and 1% annual chance floodplain were and are established by the January 16, 1976 flood insurance study and amendments thereto. The flood drainage areas generally include small streams or the upper reaches of major streams.

Flood elevation determination means a determination by the administrator of the water surface elevations of the base flood, that is, the flood level that has a one percent or greater chance of occurrence in any given year.

Flood elevation study means an examination, evaluation and determination of flood hazards and, if appropriate, corresponding water surface elevations.

Flood fringe is that area of the floodplain, outside of the floodway, that has a one percent chance of flood occurrence in any one year.

Flood hazard boundary map (FHBM) means an official map of a community, issued by the administrator, where the boundaries of the flood areas having special hazards have been designated as zones A.

Flood insurance rate map (FIRM) means an official map of a community, on which the flood insurance study has delineated both the special flood hazard boundaries and the zones establishing insurance rates applicable to the community.

Flood insurance study is the official report provided by the Federal Emergency Management Agency. The report contains flood profiles, as well as the flood boundary floodway map and 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 "flooding").

Floodplain management means the operation of an overlay 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 ordinances, grading ordinances and erosion control ordinances) 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.

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.

Floodway or regulatory 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.

Floodway encroachment lines means the lines marking the limits of floodways on federal, state and local floodplain maps.

Freeboard means a factor of safety usually expressed in feet above a flood level for purposes of floodplain management. "Freeboard" tends to compensate for the many unknown factors that could contribute to flood heights greater than the height calculated for selected size flood and floodway conditions, such as wave action, clogged bridge openings, and the hydrological effect of urbanization of the watershed.

Functionally dependent use means a use which cannot perform its intended purpose unless it is located or carried out in close proximity to water. This term includes only docking facilities, port facilities that are necessary for the loading and unloading of 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.

Historic structure means 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 the historical significance of a registered historic district or a district preliminarily determined by the Secretary to qualify as a registered historic district; or

(3) Individually listed on a state inventory of historic places in states with historic preservation programs which have been approved by the Secretary of the Interior; or

(4) Individually listed on a local inventory of 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 means 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 means 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 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 section.

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 one hundred eighty (180) consecutive days. For insurance purposes the term "manufactured home" does not include recreational vehicle, park trailer, travel trailer, and other similar vehicles.

Manufactured home park or subdivision means a parcel (or contiguous parcels) of land divided into two (2) or more manufactured home lots for rent or sale.

Map means the Flood Hazard Boundary Map (FHBM) or the Flood Insurance Rate Map (FIRM) for a community issued by the agency.

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 the purpose of determining insurance rates, structures for which the "start of construction" commenced on or after December 31, 1974 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 October 1, 1973 and includes any subsequent improvements to such structures.

New manufactured home park or subdivision means a manufactured home park or subdivision for which the construction of facilities for servicing the lot 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) was completed on or after October 1, 1973.

Participating community. See "eligible community."

Person includes any individual or group of individuals, corporation, partnership, association, or any other entity, including federal, state and local governments and agencies.

Principally above ground means that at least fifty-one (51) percent of the actual cash value of the structure, less land value, is above ground.

Overlay district is a district in which additional requirements act in conjunction with the underlying zoning district(s). The original zoning district designation does not change.

Recreational vehicle means a vehicle which is:

(1) Built on a single chassis;

(2) Four hundred (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.

Regulatory flood. See "base flood."

Regulatory floodway. See "floodway."

Remedy a violation means to bring the structure or other development into compliance with state or local floodplain management regulations.

Sheet flow area. See "area of shallow flooding."

Special flood hazard area. See "area of special flood hazard."

Special hazard area means an area having special flood hazards and shown on an FHBM or FIRM as Zone A, AO, AE, A99, AH or X shaded, other flood areas.

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 one hundred eighty (180) days of the permit date. The actual start means 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. For a substantial improvement, the actual start of construction means the first alteration of any wall, ceiling, floor, or other structural part of a floor, or other structural part of a building, whether or not that alteration affects the external dimensions of the building.

State coordinating agency means the agency of the state, or other office designated by the governor of the state or by state statute at the request of the administrator to assist in the implementation of the National Flood Insurance Program in that state.

Structure means , for floodplain management purposes, a walled and roofed building, including a gas or liquid storage tank, that is principally above ground, as well as a manufactured home. Structure, for insurance purposes, means a walled and roofed building, other than a gas or liquid storage tank, that is principally above ground and affixed to a permanent site, as well as a manufactured home on a permanent foundation. For the latter purpose, the term includes a building while in the course of construction, alteration or repair, but does not include building materials or supplies intended for use in such construction, alteration or repair, unless such materials or supplies are within an enclosed building on the premises.

Substantial damage means damage of any origin sustained by a structure whereby the cost of restoring the structure to its before damaged condition would equal or exceed fifty (50) percent of the market value of the structure before the damage occurred.

Substantial improvement means any reconstruction, rehabilitation, addition or other improvement of a structure, the cost of which equals or exceeds fifty (50) percent of the market value of the structure before the "start of construction" of the improvement. This term 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 to assure safe living conditions, or

(2) Any alteration of an "historic structure," provided that the alteration will not preclude the structure's continued designation as an "historic structure."

Variance meansa grant of relief by the community from the terms of a floodplain management regulation. Floodplain insurance requirements remain in place for any varied use or structure and cannot be varied by the community .

Violation means the failure of a structure or other development to be fully compliant with Columbia's floodplain management regulations. A structure or other development without the elevation certificate, other certifications or other evidence of compliance required by this ordinance is presumed to be in violation until such time as that documentation is provided.

Water surface elevation means the height in relation to the National Geodetic Vertical Datum of 1929, or other datum, where specified, of floods of various magnitudes and frequencies in the floodplains of riverine area.

(Ord. No. 14964, § 1, 9-3-96; Ord. No. 18432, § 1, 3-7-05; Ord. No. 20881, § 1, 2-21-11; Ord. No. 20927, § 1, 4-4-11)

(Ord. 20927, Amended, 04/04/2011, Prior Text; Ord. 20881, Amended, 02/21/2011, Prior Text; Ord. 18432, Amended, 03/07/2005, Prior Text)