Chapter 15.12
PROVISIONS FOR FLOOD HAZARD PROTECTION
Sections:
15.12.010 Development permit required.
15.12.020 Standards – Generally.
15.12.040 Materials – Methods.
15.12.055 Recreational vehicles.
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.
15.12.130 Coastal high hazard area.
15.12.135 Recreational vehicles.
15.12.137 Enclosed area below the lowest floor.
15.12.150 Livestock sanctuaries.
15.12.160 AE and A1-30 zones with base flood elevations but no floodways.
15.12.170 Areas of shallow flooding.
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 through a permit system furnished by the Kitsap County department of community development and may include, but not be limited to: electronic copies of plans 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:
A. Elevation in relation to mean sea level, of the lowest floor (including basement) of all structures;
B. Elevation in relation to mean sea level to which any structure has been floodproofed;
C. 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
D. Description of the extent to which any watercourse will be altered or relocated as a result of proposed development.
E. A V-zone design certificate (where a structure is proposed in a V, V1-30, or VE zone);
F. An engineering analysis indicating no rise of the base flood elevation (where development is proposed in a floodway); and
G. Any other such information that may be reasonably required by the floodplain administrator in order to review the application.
(Ord. 613 (2022) § 25, 2022; 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)
15.12.032 Anchoring required.
A. All new construction and substantial improvements, including those related to manufactured homes, shall be anchored to prevent flotation, collapse, or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads including the effects of buoyancy.
B. All manufactured homes shall be anchored to prevent flotation, collapse, or lateral movement, and shall be installed using methods and practices that minimize flood damage. Anchoring methods may include, but are not limited to, use of over-the-top or frame ties to ground anchors. In the absence of appropriate engineered anchoring systems from the manufacturer, FEMA-85, “Manufactured Home Installation in Flood Hazard Areas” shall be utilized to design and install anchoring systems.
(Ord. 613 (2022) § 26, 2022)
15.12.040 Materials – Methods.
Construction materials and methods shall meet the following standards:
A. All new construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage.
B. All new construction and substantial improvements shall be constructed using methods and practices that minimize flood damage.
C. 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 conditions of flooding.
(Ord. 613 (2022) § 27, 2022; 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)
15.12.055 Recreational vehicles.
Recreational vehicles placed on sites are required to either:
(1) Be on the site for fewer than one hundred eighty consecutive days; or
(2) Be fully licensed and ready for highway use, on its wheels or jacking system, is attached to the site only by quick disconnect type utilities and security devices, and have no permanently attached additions; or
(3) Meet the requirements of Section 15.12.110 and the elevation and anchoring requirements for manufactured homes.
(Ord. 527 (2015) § 7, 2015)
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.
New construction or substantial improvement of residential structures shall meet the following standards:
A. In AE and A1-30 zones or other A zoned areas where the BFE has been determined or can be reasonably obtained, residential structures shall have the lowest floor, including basement, elevated one foot or more above the BFE. Mechanical equipment and utilities shall be waterproof or elevated at least one foot above the BFE.
B. Residential structures in an AO zone shall meet the requirements in Section 15.12.170.
C. Residential structures in an unnumbered A zone for which a BFE is not available and cannot be reasonably obtained shall be reasonably safe from flooding, but in all cases the lowest floor shall be at least two feet above the highest adjacent grade.
D. Residential structures in a V, V1-30, or VE zone shall meet the requirements in Section 15.12.130.
E. 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:
1. A minimum of two openings having a total net area of one square inch for every square foot of enclosed area shall be provided.
2. The bottom of all openings shall not be higher than one foot above grade.
3. Openings may be equipped with screens, louvers, or other coverings or devices provided they permit the automatic entry and exit of floodwaters.
4. A garage attached to a residential structure, constructed with the garage floor slab below the BFE, must be designed to allow for the automatic entry and exit of floodwaters.
F. 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. 613 (2022) § 28, 2022; 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:
A. Be dry floodproofed 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 or dry floodproofed to the elevation required by ASCE 24, whichever is greater;
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 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 Section 15.16.050(B).
Nonresidential structures that are elevated, but not floodproofed, must meet the standards set forth in Section 15.12.090(B) and (C) for enclosed areas below the lowest floor.
(Ord. 613 (2022) § 29, 2022; 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 17.105.090 (Temporary permits) the use shall not exceed 180 consecutive days.
(Ord. 310 (2003) § 34, 2003)
15.12.137 Enclosed area below the lowest floor.
If buildings or manufactured homes are constructed or substantially improved with fully enclosed areas below the lowest floor, the areas shall be used solely for parking of vehicles, building access, or storage.
(Ord. 613 (2022) § 30, 2022)
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)
15.12.150 Livestock sanctuaries.
Elevated areas for the purpose of creating a flood sanctuary for livestock are allowed on farm units where livestock is allowed. Livestock flood sanctuaries shall be sized appropriately for the expected number of livestock and be elevated sufficiently to protect livestock. Proposals for livestock flood sanctuaries shall meet all procedural and substantive requirements of this chapter.
(Ord. 613 (2022) § 31, 2022)
15.12.160 AE and A1-30 zones with base flood elevations but no floodways.
In areas with BFEs (but a regulatory floodway has not been designated), no new construction, substantial improvements, or other development (including fill) shall be permitted within zones A1-30 and AE on the community’s FIRM, unless it is demonstrated that the cumulative effect of the proposed development, when combined with all other existing and anticipated development, will not increase the water surface elevation of the base flood more than one foot at any point within the community.
(Ord. 613 (2022) § 32, 2022)
15.12.170 Areas of shallow flooding.
Shallow flooding areas appear on FIRMs as AO zones with depth designations. The base flood depths in these zones range from one to three feet above ground where a clearly defined channel does not exist, or where the path of flooding is unpredictable and where velocity flow may be evident. Such flooding is usually characterized as sheet flow. In addition to other requirements in this title, the following additional provisions also apply in AO zones:
A. New construction and substantial improvements of residential structures and manufactured homes within AO zones shall have the lowest floor (including basement and mechanical equipment) elevated above the highest adjacent grade to the structure, one foot or more above the depth number specified in feet on the community’s FIRM (at least two feet above the highest adjacent grade to the structure if no depth number is specified).
B. New construction and substantial improvements of nonresidential structures within AO zones shall either:
1. Have the lowest floor (including basement) elevated above the highest adjacent grade of the building site, one foot or more above the depth number specified on the FIRM (at least two feet if no depth number is specified); or
2. 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. If this method is used, compliance shall be certified by a registered professional engineer, or architect.
C. Adequate drainage paths around structures on slopes to guide floodwaters around and away from proposed structures.
D. Recreational vehicles placed on sites within AO zones on the community’s FIRM shall either:
1. Be on the site for fewer than one hundred eighty consecutive days; or
2. Be fully licensed and ready for highway use, on its wheels or jacking system, is attached to the site only by quick disconnect type utilities and security devices, and has no permanently attached additions; or
3. Meet the requirements of subsections (A) and (C) of this section and the anchoring requirements for manufactured homes in Section 15.12.032.
(Ord. 613 (2022) § 33, 2022)