Chapter 15.12
PROVISIONS FOR FLOOD HAZARD PROTECTION

Sections:

15.12.010    Development permit required.

15.12.020    Standards – Generally.

15.12.030    Structural systems.

15.12.040    Materials – Methods.

15.12.050    Utilities.

15.12.060    Subdivision proposals.

15.12.070    Review of building permits.

15.12.080    Specific standards designated.

15.12.090    Residential construction.

15.12.100    Nonresidential construction.

15.12.110    Manufactured homes.

15.12.120    Floodways.

15.12.130    Coastal high hazard area.

15.12.135    Recreational vehicles.

15.12.140    Critical facility.

15.12.010 Development permit required.

A development permit shall be obtained before construction or development begins within any area of special flood hazard established in Section 15.04.040. The permit shall be for all structures including manufactured homes, as set forth in Chapter 15.08. Application for a development permit shall be made on forms furnished by the Kitsap County Department of Community Development and may include, but not be 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. Specifically, the following information is required:

(1)    Elevation in relation to mean sea level, of the lowest floor (including basement) of all structures;

(2)    Elevation in relation to mean sea level 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 in Section 15.12.100; and

(4)    Description of the extent to which any watercourse will be altered or relocated as a result of proposed development.

(Ord. 310 (2003) § 22, 2003: Ord. 80 (1980) § 4.1, 1980)

15.12.020 Standards – Generally.

In all areas of special flood hazards the standards set out in Sections 15.12.030 through 15.12.070 are required.

(Ord. 80 (1980) § 5.1, 1980)

15.12.030 Structural systems.

Structural systems of buildings or structures shall be constructed, connected and anchored to resist flotation, collapse or permanent lateral movement due to loads from flooding equal to the base flood elevation.

The structural system shall be designed in accordance with well-established engineering principles and with consideration of hydrodynamic and hydrostatic loads. The required loading shall be established by site-specific criteria or approved national standards.

(Ord. 310 (2003) § 23, 2003: Ord. 80 (1980) § 5.1-1, 1980)

15.12.040 Materials – Methods.

Construction materials and methods shall meet the following standards:

(1)    All new construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage.

(2)    All new construction and substantial improvements shall be constructed using methods and practices that minimize flood damage.

(3)    All new or replacement electrical equipment and heating, ventilating, air conditioning and other service facilities shall be placed at least one foot above the base flood elevation or protected to prevent water from entering or accumulating within the system components during floods up to the base flood elevation.

(Ord. 310 (2003) § 24, 2003: Ord. 80 (1980) § 5.1-2, 1980)

15.12.050 Utilities.

Utilities shall meet the following standards:

(1)    All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of floodwaters into the system;

(2)    All new and replacement water supply systems shall be located on high ground that is not in the floodway.

(3)    New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of floodwaters into the systems and discharge from the systems into floodwaters;

(4)    On-site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding; and

(5)    All water supply systems and sewage disposal systems shall meet the standards contained in Chapter 13.04 of this code (Comprehensive Water and Sewer Plan); and Chapter 9.52 of this code (Bremerton-Kitsap County Health District).

(Ord. 310 (2003) § 25, 2003: Ord. 80 (1980) § 5.1-3, 1980)

15.12.060 Subdivision proposals.

Subdivision proposals shall meet the following standards:

(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 to minimize flood damage;

(3)    All subdivision proposals shall have adequate drainage provided to reduce exposure to flood damage; and

(4)    If base flood elevation data has not been provided or is not available from another authoritative source, it shall be generated by a licensed professional engineer for subdivision proposals and other proposed development, which contain at least fifty lots or five acres (whichever is less).

(Ord. 310 (2003) § 26, 2003: Ord. 80 (1980) § 5.1-4, 1980)

15.12.070 Review of building permits.

Where elevation data is not available, either through the Flood Insurance Study FIRM or from another authoritative source, applications for building permits shall be reviewed to assure that proposed construction will be reasonably safe from flooding. The test of reasonableness is a county judgment and includes use of historical data, high water marks, photographs of past flooding, etc., where available. Failure to elevate at least two feet above the highest adjacent grade in these zones may result in higher flood insurance rates.

(Ord. 310 (2003) § 27, 2003: Ord. 80 (1980) § 5.1-5, 1980)

15.12.080 Specific standards – Designated.

In all areas of special flood hazards where base flood elevation data has been provided (Zones A1-30, AH, and AE) as set forth in Section 15.04.040 or Section 15.16.040, the provisions set forth in Sections 15.12.090 through 15.12.130 are required.

(Ord. 310 (2003) § 28, 2003: Ord. 80 (1980) § 5.2, 1980)

15.12.090 Residential construction.

(1)    New construction and substantial improvement of any residential structure shall have the lowest floor, including basement, elevated one foot or more above base flood elevation.

(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 floodwaters. Designs for meeting this requirement must either be certified by a registered professional engineer or must exceed the following minimum criteria:

(a)    A minimum of two openings having a total net area of not less than four square feet or one square inch for every square foot of enclosed area, whichever is greater, shall be provided.

(b)    The bottom of all openings shall not be higher than one foot above grade.

(c)    Openings may be equipped with screens, louvers, or other coverings or devices provided they permit the automatic entry and exit of floodwaters.

(3)    The finished ground level of any underfloor space shall be equal to or higher than the outside finished ground level. Subgrade crawl spaces are prohibited.

(Ord. 310 (2003) § 29, 2003: Ord. 80 (1980) § 5.2-1, 1980)

15.12.100 Nonresidential construction.

New construction and substantial improvement of any commercial, industrial or other nonresidential structure shall either have the lowest floor, including basement, elevated one foot or more above base flood elevation; or, together with attendant utility and sanitary facilities, shall:

(1)    Be flood proofed so that below one foot or more above the base flood level, the structure is watertight with walls substantially impermeable to the passage of water; and

(2)    Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy; and

(3)    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 provisions of this section based on their development and/or review of the structural design, specifications and plans. Such certifications shall be provided to the official as set forth in subsection (2) of Section 15.16.050.

Nonresidential structures that are elevated, but not flood-proofed, must meet the standards set forth in Section 15.12.090(2) and (3) for enclosed areas below the lowest floor.

(Ord. 310 (2003) § 30, 2003: Ord. 80 (1980) § 5.2-2, 1980)

15.12.110 Manufactured homes.

(1)    All manufactured homes to be placed or substantially improved on sites:

(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 on which a manufactured home has incurred substantial damage as the result of a flood;

shall be elevated such that the lowest floor of the manufactured home is located one foot or more above the base flood elevation, and be securely anchored in accordance with Title 14 of this code and Washington Administrative Code (WAC) 296-150M-0610.

(2)    Manufactured homes to be placed or substantially improved on sites in an existing manufactured home park or subdivision that are not subject to the above manufactured home provisions shall be elevated so that either:

(a)    The lowest floor of the manufactured home is elevated one foot or more above the base flood elevation; or

(b)    Reinforced piers support the manufactured home chassis or other foundation elements of at least equivalent strength that are no less than 36 inches in height above grade and securely anchored in accordance with Title 14 of this code and Washington Administrative Code (WAC) 296-150M-0610.

(3)    The finished ground level of any underfloor space below a manufactured home shall be equal to or higher than the outside finished ground level. Subgrade crawl spaces are prohibited.

(Ord. 310 (2003) § 31, 2003: Ord. 80 (1980) § 5.2-3, 1980)

15.12.120 Floodways.

Located within areas of special flood hazard established in Section 15.04.050 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 apply:

(1)    Encroachments, including 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 in accordance with standard engineering practice that the proposed 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 areas; and

(b)    Repairs, reconstruction or improvements to a structure, the cost of which does not exceed fifty percent of the market value of the structure either:

1.    Before the repair or reconstruction is started; or

2.    If the structure has been damaged and is being restored, before the damage occurred.

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 are the minimum necessary to assure safe living conditions, or to structures identified as historic places, may not be included in the fifty percent, subject to the director’s approval.

(3)    All new construction and substantial improvements shall comply with all applicable provisions of this chapter.

(Ord. 310 (2003) § 32, 2003: Ord. 80 (1980) § 5.3, 1980)

15.12.130 Coastal high hazard area.

Coastal high hazard areas (V zones) are located within the areas of special flood hazard established in Sections 15.04.030 through 15.04.080, designated as Zones V1-30, VE or V. These areas have special flood hazards associated with high velocity waters from tidal surges and, therefore, the following additional requirements apply:

(1)    All new construction and substantial improvements in Zones V1-30 and VE (V, if base flood elevation data is available) on the county’s FIRM shall be elevated on pilings and columns so that:

(a)    The bottom of the lowest horizontal structural member of the lowest floor (excluding the pilings or columns) is elevated one foot or more above base flood level; and

(b)    The pile or column foundation and structure attached thereto is anchored to resist flotation, collapse and lateral movement due to the effects of wind loads and water loads from flooding equal to the base flood elevation, acting simultaneously on building components.

A registered professional engineer shall develop or review the structural design, specifications, and plans for the construction, and shall certify that the design and methods of construction to be used are in accordance with accepted standards of practice for meeting the provisions of this title.

(2)    Elevation data shall be provided to the County indicating the elevation (in relation to mean sea level) of the bottom of the lowest structural member of the lowest floor (excluding pilings and columns) of all new and substantially improved structures in Zones V-1-30, VE, and V on the county’s FIRM and whether or not such structures contain a basement. The county shall maintain a record of all such information.

(3)    All new construction within Zones V1-30, VE, and V on the county’s FIRM shall be located landward of the reach of mean high tide.

(4)    All new construction and substantial improvements within Zones V1-30, VE, and V on the county’s FIRM shall have the space below the lowest floor either free of obstruction or constructed with non-supporting breakaway walls, open wood lattice-work, or insect screening intended to collapse under wind and water loads without causing collapse, displacement, or other structural damage to the elevated portion of the building or supporting foundation system. For the purposes of this section, a breakaway wall shall have a design safe loading resistance of not less than ten and no more than twenty pounds per square foot. Use of breakaway walls which exceed a design safe loading resistance of twenty pounds per square foot (either by design or when so required by local codes) may be permitted only if a registered professional engineer certifies that the designs proposed meet the following conditions:

(a)    Breakaway wall collapse will result from water load less than that which would occur during the base flood; and

(b)    The elevated portion of the building and supporting foundation system will not be subject to collapse, displacement, or other structural damage due to the effects of wind loads and water loads from flooding equal to the base flood elevation, acting simultaneously on building components (structural and non-structural).

If breakaway walls are utilized, such enclosed space shall be useable solely for the parking of vehicles, building access, or storage. Such space shall not be used for human habitation.

(5)    The use of fill is prohibited for the structural support of buildings within Zones V1-30, V, and VE on the county’s FIRM.

(6)    Man-made alterations of sand dunes are prohibited within Zones V1-30, VE, and V on the county’s FIRM, which would increase potential flood damage.

(7)    All manufactured homes to be placed or substantially improved within Zones V1-30, V, and VE on the county’s FIRM shall meet all of the standards of this section.

(Ord. 310 (2003) § 33, 2003: Ord. 80 (1980) § 5.4, 1980)

15.12.135 Recreational vehicles.

In accordance with Kitsap County Code, Title 17, recreational vehicles may not be permanently installed. Where permitted for use for temporary habitation, in accordance with Kitsap County Code Section 17.455.090, (Temporary Permits), the use shall not exceed 180 consecutive days.

(Ord. 310 (2003) § 34, 2003)

15.12.140 Critical facility.

Construction of new critical facilities shall be, to the extent possible, located outside the limits of the Special Flood Hazard Area (SFHA) (100-year floodplain). Construction of new critical facilities shall be permissible within the SFHA if no feasible alternative site is available. Critical facilities constructed within the SFHA shall have the lowest floor elevated three feet or to the height of the 500-year flood, whichever is higher. Access to and from the critical facility shall also be protected to the height utilized above. Floodproofing and sealing measures must be taken to ensure that toxic substances will not be displaced by or released into floodwaters. Access routes elevated to or above the level of the base flood elevation shall be provided to all critical facilities to the extent possible.

(Ord. 310 (2003) § 35, 2003)