Chapter 16.15
FLOOD DAMAGE PREVENTION
Sections:
Article I. General Provisions
16.15.010 Purpose.
16.15.020 Methods for reducing flood loss.
16.15.030 Definitions.
16.15.040 Lands to which this chapter applies.
16.15.050 Adoption of report and FIRM.
16.15.055 Stormwater management.
16.15.060 Penalty for noncompliance.
16.15.070 Abrogation and greater restrictions.
16.15.080 Interpretation.
16.15.090 Warning and disclaimer.
Article II. Administration
16.15.100 Development permit required.
16.15.110 Application for development permit.
16.15.120 Local administrator.
16.15.130 Local administrator – Duties.
16.15.140 Local administrator – Use of other base flood data.
16.15.150 Local administrator – Information to be obtained.
16.15.160 Local administrator – Alteration of watercourses.
16.15.170 Local administrator – Interpretation of FIRM boundaries.
16.15.180 Variances and appeals.
16.15.190 Variances – Permissible conditions.
Article III. Flood Hazard
Reduction – General Standards
16.15.200 Flood hazard reduction – Anchoring.
16.15.210 Flood hazard reduction – Construction materials and methods.
16.15.220 Flood hazard reduction – Utilities.
16.15.230 Flood hazard reduction – Subdivision proposals.
16.15.240 Flood hazard reduction – Review of building permits.
Article IV. Flood Hazard
Reduction – Specific Standards
16.15.250 Flood hazard reduction – Residential construction.
16.15.260 Flood hazard reduction – Nonresidential construction.
16.15.270 Flood hazard reduction – Manufactured homes.
16.15.280 Flood hazard reduction – Recreational vehicles.
16.15.290 Flood hazard reduction – Floodways.
16.15.300 Flood hazard reduction – Encroachments.
16.15.310 Critical facility.
Article I. General Provisions
16.15.010 Purpose.
(1) The flood hazard areas of the City are subject to periodic inundation resulting in loss of life and property, health and safety hazards, disruption of commerce and governmental services, extraordinary public expenditures for flood protection and relief, and impairment of the tax base, all of which adversely affect the public health, safety and general welfare.
(2) These flood losses are caused by the cumulative effect of obstructions in areas of special flood hazards which increase flood heights and velocities, and, when inadequately anchored, damage uses in other areas. Uses that are inadequately floodproofed, elevated, or otherwise protected from flood damage also contribute to the flood loss. It is the purpose of this chapter to promote the public health, safety, and general welfare and to minimize public and private losses due to flood conditions in specific areas by provisions designed:
(a) To protect human life and health;
(b) To minimize the expenditure of public money and costly flood control projects;
(c) To minimize the need for rescue and relief efforts associated with flooding and typically undertaken at the expense of the general public;
(d) To minimize prolonged business interruptions;
(e) To minimize damage to public facilities and utilities such as water and gas mains, electric, telephone and sewer lines and streets and bridges located in areas of special flood hazard;
(f) To help maintain a stable tax base by providing for the sound use and development of special flood hazard areas so as to minimize future flood blight areas;
(g) To ensure that potential buyers are notified that property is in an area of special flood hazard; and
(h) To ensure that those who occupy special flood hazard areas assume responsibility for their actions. (Ord. 100-98 § 1)
16.15.020 Methods for reducing flood loss.
In order to accomplish its purposes, this chapter sets forth methods and provisions for:
(1) Restricting or prohibiting uses which are dangerous to health, safety and property due to water or erosion hazards or which result in damaging increases in erosion, flood heights or velocities;
(2) Requiring that uses vulnerable to floods, including facilities which serve such uses, be protected against flood damage at the time of initial construction;
(3) Controlling the alteration of natural floodplains, stream channels and natural protective barriers which help accommodate or channel flood water;
(4) Controlling filling, grading, dredging and other development which may increase flood damage; and
(5) Preventing or regulating the construction of flood barriers which unnaturally divert flood water or increase flood hazards in other areas. (Ord. 100-98 § 1)
16.15.030 Definitions.
Unless specifically defined below, words or phrases used in this chapter shall be interpreted so as to give them the meaning they have in common usage and to give this chapter its most reasonable application.
(1) “Appeal” means a request for review of the interpretation of any provision of this chapter or a request for a variance therefrom.
(2) “Area of special flood hazard” means the land in the floodplain within the City which is subject to a one percent or greater chance of flooding in any given year. This area’s designation on maps always includes the letters A or V.
(3) “Base flood” means the flood having a one percent chance of being equaled or exceeded in any given year and is also referred to as the 100-year flood. The base flood’s designation on maps always includes the letters A or V.
(4) “Basement” means any area of a building having its floor subgrade (below ground level) on all sides.
(5) “Critical facility” means a facility for which even a slight chance of flooding might be too great. Critical facilities include, but are not limited to, schools, nursing homes, hospitals, police, fire and emergency response installations, and installations which produce, use or store hazardous materials or hazardous waste.
(6) “Development” means any manmade change to improved or unimproved real property, including but not limited to buildings or other structures or mining, dredging, filling, grading, paving, excavation, drilling operations or storage of equipment or materials located within the area of special flood hazard.
(7) “Elevated building,” for insurance purposes, means a nonbasement building which has its lowest elevated floor raised above ground level by foundation walls, shear walls, posts, piers, pilings or columns.
(8) “Existing manufactured home park or subdivision” means a manufactured home park 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 adopted floodplain management regulations.
(9) “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.
(10) “Flood” or “flooding” means a general and temporary condition of partial or complete inundation of normally dry land areas from (a) the overflow of inland or tidal waters; and/or (b) the unusual and rapid accumulation of surface water runoff from any source.
(11) “Flood insurance rate map” or “FIRM” means the official map on which the Federal Insurance Administration has delineated both the areas of special flood hazards and the risk premium zones applicable to the City.
(12) “Flood insurance study” means the official report provided by the Federal Insurance Administration which includes flood profiles, the flood boundary-floodway map, and the water surface elevation of the base flood.
(13) “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.
(14) “Lowest floor” means the lowest floor of the lowest enclosed area, including any basement. An unfinished or flood resistant enclosure which is usable solely for parking of vehicles, building access or storage, located 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 nonelevation design requirements of CMC 16.15.250(2).
(15) “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 attached to the required utilities. The term “manufactured home” does not include a recreational vehicle.
(16) “Manufactured home park or subdivision” means a parcel or contiguous parcels of land divided into two or more manufactured home lots for rent or sale.
(17) “New construction” means any structure for which the start of construction commenced on or after the effective date of the ordinance codified in this chapter.
(18) “New 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, is completed on or after the effective date of adopted floodplain management regulations.
(19) “Recreational vehicle” means a vehicle which is:
(a) Built on a single chassis;
(b) Four hundred square feet or less when measured at the largest horizontal projection;
(c) Designed to be self-propelled or permanently towable by a light duty truck; and
(d) Designed primarily as temporary living quarters for recreational, camping, travel or seasonal use and not for use as a permanent dwelling.
(20) “Start of construction” includes substantial improvement, and means the date the building permit was issued, provided the actual start of construction, repair, reconstruction, placement or other improvement is 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 a slab or footings, the installation of piles, the construction of columns or any other 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 or the installation of streets and/or walkways or excavation for a basement, footings, piers, or foundations or the erection of temporary forms or the installation of the property or accessory buildings such as garages or sheds not occupied as dwelling units or not part of the main structure. With respect to 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.
(21) “Structure” means a walled and roofed building including a gas or liquid storage tank that is principally above ground.
(22) “Substantial damage” means damage of any origin sustained by a structure whereby the cost of restoring the structure to its predamaged condition would equal or exceed 50 percent of the market value of the structure before the damage occurred.
(23) “Substantial improvement” means any repair, reconstruction or improvement of a structure, the cost of which equals or exceeds 50 percent of the market value of the structure: (a) before the improvement or repair is started; or (b) if the structure has been damaged and is being restored, before the damage occurred. For purposes of this definition, “substantial improvement” is considered to occur when the first alteration of any wall, ceiling, floor or other structural part of the building commences, whether or not that alteration affects the external dimensions of the structure.
The term does not, however, include: (a) any project to improve a structure to correct existing violations of State or local health, sanitary, or safety code specifications which have been identified by the local enforcement official and which are the minimum necessary to assure safe living conditions; or (b) any alteration of a structure listed on the National Register of Historic Places or a State Inventory of Historic Places.
(24) “Variance” means a grant of relief from the requirements of this chapter which permits construction in a manner that would otherwise be prohibited by this chapter.
(25) “Water dependent” means a structure for commerce or industry which is dependent on the water by reason of the intrinsic nature of its operations and cannot exist in any other location. (Ord. 30-05 § 1; Ord. 23-00 § 1; Ord. 100-98 § 1)
16.15.040 Lands to which this chapter applies.
This chapter shall apply to all areas of special flood hazard located within the City limits. (Ord. 100-98 § 1)
16.15.050 Adoption of report and FIRM.
The areas of special flood hazard identified by the Federal Insurance Administration in a scientific and engineering report entitled “The Flood Insurance Study for King County, Washington and incorporated areas,” dated March 30, 1998, as amended, with the accompanying FIRM, as amended, are hereby adopted by reference as though fully set forth herein. The flood insurance study is on file at Covington City Hall. The best available information for flood hazard area identification as outlined in CMC 16.15.140 shall be the basis for regulation until a new FIRM is issued which incorporates the data utilized under said section. (Ord. 100-98 § 1)
16.15.055 Stormwater management.
(1) Stormwater management shall be provided for projects located within lands to which this chapter applies. Stormwater management facilities shall not be located within floodways. Stormwater management facilities may be located within areas of encroachment, subject to approval by the City Engineer; provided, that the increase in the water surface elevation of the base flood does not exceed the limits of CMC 16.15.300.
(2) Stormwater management facilities shall be designed in accordance with CMC Title 13. (Ord. 13-09 § 21)
16.15.060 Penalty for noncompliance.
Unless a variance is properly granted, no structure or land shall hereafter be constructed, located, extended, converted or altered without full compliance with the terms of this chapter and any other applicable regulations. Any violation of the provisions of this chapter by failure to comply with any of its requirements, including but not limited to, violations of conditions and safeguards established in connection with conditions, shall constitute a misdemeanor. Any person who violates this chapter or fails to comply with any of its requirements shall be guilty of a misdemeanor upon conviction thereof be fined not more than $1,000 or imprisoned for not more than 90 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 City from taking such other lawful action as deemed necessary to prevent or remedy any violation. (Ord. 100-98 § 1)
16.15.070 Abrogation and greater restrictions.
This chapter is not intended to repeal, abrogate, or impair any existing easements, covenants or deed restrictions. However, where this chapter and any other ordinance, easement, covenant or deed restriction conflict or overlap, the one which imposes the more stringent restrictions shall prevail. (Ord. 100-98 § 1)
16.15.080 Interpretation.
In the interpretation and application of this chapter 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. (Ord. 100-98 § 1)
16.15.090 Warning and disclaimer.
The degree of flood protection required by this chapter is considered reasonable for regulatory purposes and is based on scientific and engineering considerations. More extensive floods can and will occur on rare occasions. Flood heights may be increased by manmade or natural causes. This chapter does not imply that land outside the areas of special flood hazard or uses permitted within such areas will be free from flooding or flood damage. This chapter shall not create liability on the part of the City, any officer or employee thereof or the Federal Insurance Administration for any flood damage that results from reliance on this chapter or any administrative decision lawfully made hereunder. (Ord. 100-98 § 1)
Article II. Administration
16.15.100 Development permit required.
A development permit shall be obtained before construction or development begins within any area of special flood hazard established in CMC 16.15.050. The permit shall be for all structures, including manufactured homes, and for all development. (Ord. 100-98 § 1)
16.15.110 Application for development permit.
An application for a development permit shall be made on forms furnished by the City administrator and will include such information as is required by the local administrator, including but not limited to plans in duplicate drawn to scale showing the nature, location, dimensions, and elevations of the area in question, existing or proposed structures, fill, storage of materials, drainage facilities and the location of the foregoing. In addition, the following information shall be required from all applicants:
(1) In relation to mean sea level, the elevation of the lowest floor of all structures, including the basement;
(2) In relation to mean sea level, the elevation to which any structure has been floodproofed;
(3) Certification by a registered professional engineer or architect that the floodproofing methods for any nonresidential structure meet the floodproofing criteria set forth in CMC 16.15.260; and
(4) A description of the extent to which a watercourse will be altered or relocated as a result of the proposed development. (Ord. 100-98 § 1)
16.15.120 Local administrator.
The City Manager or his designee is hereby appointed to act as the local administrator of this chapter and, to that end, shall administer and implement this chapter by granting or denying development permit applications in accordance with its provisions. (Ord. 100-98 § 1)
16.15.130 Local administrator – Duties.
The duties of the local administrator shall include, but are not limited to:
(1) Reviewing all development permits to determine whether the permit requirements of this chapter have been satisfied;
(2) Reviewing all development permits to determine whether all necessary permits have been obtained from those Federal, State, or local governmental agencies from which prior approval is required; and
(3) Reviewing all development permits to determine whether the proposed development is located in the floodway and, if so, ensuring that the encroachment provisions of CMC 16.15.290(1) are satisfied. (Ord. 100-98 § 1)
16.15.140 Local administrator – Use of other base flood data.
In order to administer CMC 16.15.250 through 16.15.290 when base flood elevation data has not been provided in accordance with CMC 16.15.050, the local administrator shall obtain, review, and reasonably utilize any base flood elevation and floodway data available from any Federal, State or other source. (Ord. 100-98 § 1)
16.15.150 Local administrator – Information to be obtained.
(1) Where base flood elevation data is provided through the flood insurance study or as set forth in CMC 16.15.140, the local administrator shall obtain and record the actual elevation, in relation to mean sea level, of the lowest floor (including basement) of all new or substantially improved structures, and, in addition, shall record whether or not said structures contain basements.
(2) For all new or substantially improved floodproofed structures where base flood elevation is provided through the flood insurance study or is set forth in CMC 16.15.140, the local administrator shall:
(a) Verify and record the actual elevation, in relation to mean sea level to which the structure was floodproofed; and
(b) Maintain the floodproofing certifications required in CMC 16.15.110(3).
(3) The local administrator shall maintain for public inspection all records pertaining to and required by the provisions of this chapter. (Ord. 23-00 § 2; Ord. 100-98 § 1)
16.15.160 Local administrator – Alteration of watercourses.
Whenever any watercourse is to be altered or relocated, the local administrator shall:
(1) Notify adjacent communities and the Department of Ecology prior to any such alteration or relocation and submit evidence of such notification to the Federal Insurance Administration; and
(2) Require that maintenance be provided for within the altered or relocated portion of said watercourse so that its flood carrying capacity is not diminished. (Ord. 100-98 § 1)
16.15.170 Local administrator – Interpretation of FIRM boundaries.
The local administrator shall make all necessary interpretations as to the exact location of the boundaries of any areas of special flood hazard, for example, where there appears to be a conflict between a mapped boundary and actual field conditions. Any person contesting the location of said boundary shall be given a reasonable opportunity to appeal the interpretation as provided in CMC 16.15.180. (Ord. 23-00 § 3; Ord. 100-98 § 1)
16.15.180 Variances and appeals.
(1) The Hearing Examiner shall hear and decide any appeal or request for a variance from the requirements of this chapter. Appeals and requests for variances shall be accompanied by a fee as set forth in the current fee resolution.
(2) The Hearing Examiner shall hear and decide appeals when it is alleged that there is an error in any requirement, decision, or determination made by the local administrator in the enforcement or administration of this chapter. Appeals shall be heard in accordance with Chapter 14.45 CMC.
(3) Anyone aggrieved by the decision of the Hearing Examiner, or any taxpayer, may appeal such decision to the King County Superior Court, as provided in the Land Use Petition Act.
(4) In passing upon such appeals and variance requests, the Hearing Examiner shall consider all technical evaluations, all relevant factors and standards specified in other sections of this chapter, and, in addition:
(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 the 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 City;
(e) The necessity of a waterfront location for the facility, if applicable;
(f) The availability of alternative locations for the proposed use which are not subject to flooding or erosion damage;
(g) The compatibility of the proposed use with existing and anticipated development;
(h) The relationship of the proposed use to the comprehensive plan and the floodplain management program for that area;
(i) The safety of access to the property for ordinary and emergency vehicles in times of flood;
(j) The expected height, velocity, duration, rate of rise and sediment transport of the flood water and the effects of wave action, if applicable, expected at the site; and
(k) The cost 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, streets and bridges.
(5) Upon due consideration of the factors set forth in subsection (4) of this section as well as the purposes of this chapter, the Hearing Examiner may, in his discretion, attach such conditions to the granting of any variance as he deems necessary to further the purposes of this chapter.
(6) The local administrator shall maintain the records of all appeals and report any variances to the Federal Insurance Administration upon request. (Ord. 01-09 § 16; Ord. 20-07 § 92; Ord. 100-98 § 1)
16.15.190 Variances – Permissible conditions.
(1) As interpreted in the National Flood Insurance Program, a variance is based on the general zoning law principle, that the variance pertains to a physical piece of property, is not personal in nature and does not pertain to the structure, its inhabitants or any economic or financial circumstances. A variance primarily pertains to small lots in densely populated residential neighborhoods. As such, variances from the flood elevations should be quite rare.
(2) Providing the factors set forth in CMC 16.15.180(4) have been fully considered, in general, the only condition for which a variance from the elevation standard may be granted is new construction and substantial improvements which are to be erected on a lot of one-half acre or less in size contiguous to and surrounded by lots with existing structures which are constructed below the base flood level. As the lot size increases, the technical justification required for issuing the variance will also increase.
(3) A variance may be issued for the reconstruction, rehabilitation or restoration of any structure listed on the National Register of Historic Places or the State Inventory of Historic Places without regard to the procedures set forth in this section.
(4) A variance shall not be issued within a designated floodway if any increase in flood levels during the base flood discharge would thereby result.
(5) A variance shall only be issued upon:
(a) A showing of good and sufficient cause;
(b) A determination that denial of the variance application would result in exceptional hardship to the applicant;
(c) A determination that granting the variance will not result in increased flood heights, additional threats to public safety, extraordinary public expense, create a nuisance, cause fraud on or victimization of the public, or conflict with existing local laws or ordinances; and
(d) A determination that, considering the flood hazard, the variance is the minimum necessary to afford relief.
(6) In very limited circumstances, a variance to allow a lesser degree of floodproofing than watertight or dry-floodproofing may be issued for a nonresidential building where it can be demonstrated that such action will have low damage potential, complies with all other variance criteria except subsection (2) of this section, and otherwise complies with CMC 16.15.200 and 16.15.210.
(7) Any applicant to whom a variance is granted shall be afforded written notice that the structure will be permitted to be built with a lowest floor elevation below the base flood elevation and that the cost of flood insurance will be commensurate with the increased risk resulting from the reduced lowest floor elevation. (Ord. 100-98 § 1)
Article III. Flood Hazard Reduction –
General Standards
16.15.200 Flood hazard reduction – Anchoring.
In all areas of special flood hazard, the following standards for anchoring shall be complied with:
(1) All new construction and substantial improvements shall be anchored to prevent flotation, collapse, or lateral movement of the structure.
(2) All manufactured homes must likewise be anchored to prevent flotation, collapse, or lateral movement and, in addition, shall be installed using methods and practices that minimize flood damage. Anchoring methods may include, but are not limited to, over-the-top or frame ties to ground anchors and additional techniques referred to in the Federal Emergency Management Agency’s “Manufactured Home Installation in Flood Hazard Areas” guidebook. (Ord. 100-98 § 1)
16.15.210 Flood hazard reduction – Construction materials and methods.
In all areas of special flood hazard, the following standards for construction materials and methods shall be complied with:
(1) All new construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage;
(2) All new construction and substantial improvements shall be constructed using methods and practices that minimize flood damage; and
(3) Electrical, heating, ventilation, plumbing, and air-conditioning equipment and other service facilities shall be designed and/or otherwise elevated or located so as to prevent water from entering or accumulating within the components during conditions of flooding. (Ord. 100-98 § 1)
16.15.220 Flood hazard reduction – Utilities.
In all areas of special flood hazard, the following standards pertaining to utilities shall be complied with:
(1) All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of flood water into the system;
(2) All new and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of flood water into the systems and, in addition, discharge from the systems into flood water; and
(3) All on-site waste disposal systems shall be located so as to avoid impairment to them or contamination from them during flooding. (Ord. 100-98 § 1)
16.15.230 Flood hazard reduction – Subdivision proposals.
In all areas of special flood hazard, the following standards pertaining to subdivision proposals shall be complied with:
(1) All subdivision proposals shall be consistent with the need to minimize flood damage;
(2) All subdivision proposals shall have public utilities and facilities such as sewer, gas, electrical and water systems located and constructed so as to minimize or eliminate flood damage;
(3) All subdivision proposals shall have adequate drainage provided to reduce exposure to flood damage; and
(4) Where base flood elevation data has not been provided or is not available from another authoritative source, such data shall be generated for subdivision proposals and other proposed developments which contain at least 50 lots or five acres, whichever is less. (Ord. 23-00 § 4; Ord. 100-98 § 1)
16.15.240 Flood hazard reduction – Review of building permits.
In all areas of special flood hazard, where elevation data is not available through the flood insurance study or from some other authoritative source pursuant to CMC 16.15.140, an application for a building permit shall be reviewed to assure that the proposed construction will be reasonably safe from flooding. The test of reasonableness is a local judgment and may include, but is not limited to, the use of historical data, high water marks, and photographs of past flooding, where available. Failure to elevate at least two feet above grade in these zones may result in higher insurance rates. (Ord. 100-98 § 1)
Article IV. Flood Hazard Reduction – Specific Standards
16.15.250 Flood hazard reduction – Residential construction.
In all areas of special flood hazard where base flood elevation data has been provided pursuant to CMC 16.15.050 or 16.15.140, the following provisions pertaining to residential construction shall be complied with:
(1) New construction and substantial improvement of any residential structure shall have the lowest floor, including any basement, elevated one foot above the base flood elevation; and
(2) Fully enclosed areas below the lowest floor that are subject to flooding are prohibited, or shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwater. Designs for meeting this requirement must be certified by a registered professional engineer or architect or must 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; and
(c) Openings may be equipped with screens, louvers or other coverings, or devices; provided, that they permit the automatic entry and exit of floodwater. (Ord. 100-98 § 1)
16.15.260 Flood hazard reduction – Nonresidential construction.
In all areas of special flood hazard where base flood elevation data has been provided pursuant to CMC 16.15.050 or 16.15.140, the following provisions pertaining to nonresidential construction shall be complied with:
(1) New construction and substantial improvement of any commercial, industrial or other nonresidential structure shall have the lowest floor, including basement, elevated one foot above the base flood elevation, or, alternatively, together with attendant utility and sanitary facilities, shall:
(a) Be floodproofed so that below one foot above the base flood level the structure is watertight with walls substantially impermeable to the passage of water;
(b) Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy; and
(c) Be certified by a registered professional engineer or architect that the design and methods of construction are in accordance with accepted standards of practice for meeting the provisions of this subsection based on his/her development and/or review of the structural design, specifications and plans. Such certifications shall be provided to the local administrator as set forth in CMC 16.15.150(2).
(2) Nonresidential structures that are elevated and not floodproofed must meet the standards for space below the lowest floor set forth in CMC 16.15.250(2).
(3) Applicants floodproofing nonresidential buildings shall be notified that flood insurance premiums will be based on rates that are one foot below the floodproofed level, that is, a building floodproofed to the base flood level will be rated as one foot below. (Ord. 100-98 § 1)
16.15.270 Flood hazard reduction – Manufactured homes.
In all areas of special flood hazard where base flood elevation data has been provided pursuant to CMC 16.15.050 or 16.15.140, the following provisions pertaining to manufactured homes shall be complied with:
(1) Any manufactured home which is to be placed or substantially improved within Zones A1-30, AH or AE on the City’s FIRM on sites which are: (a) outside of a manufactured home park or subdivision; (b) in a new manufactured home park or subdivision; (c) in an expansion to an existing manufactured home park or subdivision; or (d) in an existing manufactured home park or subdivision in which a manufactured home has incurred substantial damage as the result of a flood, shall be elevated on a permanent foundation so that the lowest floor of the manufactured home is elevated one foot above the base flood elevation and, in addition, securely anchored to an adequately anchored foundation system so as to resist flotation, collapse and lateral movement.
(2) Any manufactured home which is to be placed or substantially improved in an existing manufactured home park or subdivision located within Zones A1-30, AH or AE on the City’s FIRM and which is not subject to the provisions of subsection (1) of this section shall be elevated so that: (a) the lowest floor of the manufactured home is elevated one foot above the base flood elevation; or (b) the manufactured home chassis is supported by reinforced piers or other foundation elements of at least equivalent strength that are no less than 36 inches in height above grade and, in addition, securely anchored to an adequately anchored foundation system so as to resist flotation, collapse, and lateral movement. (Ord. 30-05 § 2; Ord. 100-98 § 1)
16.15.280 Flood hazard reduction – Recreational vehicles.
In all areas of special flood hazard where base flood elevation data has been provided pursuant to CMC 16.15.050 or 16.15.140, the following provisions pertaining to recreational vehicles shall be complied with: any recreational vehicle placed on a site within Zones A1-30, AH or AE on the City’s FIRM shall:
(1) Be on the site for fewer than 180 consecutive days;
(2) Be fully licensed and ready for highway use, on its wheels or jacking system and attached to the site only by quick disconnect type utilities and security devices, and have no permanently attached addition(s); or
(3) Meet the requirements of CMC 16.15.270 and the elevation and anchoring requirements for manufactured homes. (Ord. 100-98 § 1)
16.15.290 Flood hazard reduction – Floodways.
Located within areas of special flood hazard are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of floodwater which carries debris, potential projectiles, and erosion potential, the following provisions shall apply to areas designated as floodways:
(1) Encroachments, including but not limited to, fill, new construction, substantial improvements and other development are prohibited unless certification by a registered professional engineer is provided demonstrating through hydrologic and hydraulic analyses performed with standard engineering practice that said encroachments shall not result in any increase in flood levels during the occurrence of the base flood discharge;
(2) Construction or reconstruction of residential structures is prohibited within designated floodways, except for: (a) repairs, reconstruction or improvements to a structure which do not increase the ground floor area; and (b) repairs, reconstruction of residential structures or improvements to a structure, the cost of which does not exceed 50 percent of the market value of the structure either: (i) before the repair or reconstruction is started; or (ii) if the structure has been damaged and is being restored, before the damage occurred. Any project for improvement for 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 minimums necessary to assure safe living conditions or to be structures identified as historic places may be excluded in the 50 percent.
(3) If subsection (1) of this section is satisfied, all new construction and substantial improvements in an area designated as a floodway shall comply with all the applicable flood hazard reduction provisions of CMC 16.15.200 through 16.15.310. (Ord. 30-05 § 3; Ord. 23-00 § 5; Ord. 100-98 § 1)
16.15.300 Flood hazard reduction – Encroachments.
In all areas of special flood hazard, the cumulative effect of any proposed development, combined with all other existing and anticipated development, shall not increase the water surface elevation of the base flood more than one foot at any point. (Ord. 100-98 § 1)
16.15.310 Critical facility.
To the extent possible, the construction of any new critical facility shall be located outside the limits of the special flood hazard area (100-year floodplain). Construction of any new critical facility shall be permissible within the special flood hazard area if no feasible alternative site is available. Any critical facility constructed within said area shall have the lowest floor elevated three feet or more above the level of the base flood elevation at the site. Floodproofing and sealing measures must be taken to ensure that toxic substances will not be displaced by or released into flood waters. To the extent possible, access routes elevated to or above the level of the base flood elevation shall be provided to all critical facilities. (Ord. 100-98 § 1)