1.
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.
2.
All manufactured homes must likewise 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 (reference FEMA's "Manufactured Home Installation in Flood Hazard Areas" guidebook for additional techniques).
(Ord. 93-18 § 5.1.1, 1993; Ord. 2001-03; Ord. 2021-010, 2021)
(Ord. 2001-03; Ord. 2007-34, 2007)
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.
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. 93-18 § 5.1.2, 1993; Ord. 2001-03)
1.
The storage or processing of materials that could be injurious to human, animal, or plant life if released due to damage from flooding is prohibited in special flood hazard areas.
2.
Storage of other material or equipment may be allowed if not subject to damage by floods and if firmly anchored to prevent flotation, or if readily removable from the area within the time available after flood warning.
(Ord. 2021-010, 2021)
1.
All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of flood waters into the systems and discharges from systems into floodwaters.
2.
New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of flood waters into the systems and discharge from the systems into flood waters.
3.
On-site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding.
4.
New water wells shall be constructed in compliance with WAC 173-160-171, on high ground that is not in the floodway.
5.
Fuel storage tanks shall either be elevated or anchored using methods and practices that minimize flood damage. (consistent with FEMA's "Protecting Building Utilities From Flood Damage" guidebook for techniques).
(Ord. 93-18 § 5.1.3, 1993; Ord. 2001-03; Ord. 2007-22, 2007; Ord. 2021-010, 2021)
All subdivisions as well as new development shall:
1.
Be consistent with the need to minimize flood damage.
2.
Have public utilities and facilities such as sewer, gas, electrical, and water systems located and constructed to minimize flood damage.
3.
Have adequate drainage provided to reduce exposure to flood damage.
4.
Where base flood elevation data has not been provided or is not available from another authoritative source, it shall be generated for subdivision proposals and other proposed developments containing greater than 50 lots or 5 acres (whichever is lesser) and shall be included as part of the application and shall be noted on the final plan set.
5.
All subdivisions shall s how on the face of both the preliminary and final plat, for either short or long plats, the boundary of the 100year floodplain and floodway.
(Ord. 93-18 § 5.1.4, 1993; Ord. 2001-03; Ord. 2007-22, 2007; Ord. 2021-010, 2021; Ord. 2025-001, 1/7/2025)
Where elevation data is not available either through the flood insurance study, FIRM, or from another authoritative source (KCC § 14.08.120), applications for floodplain development shall be reviewed to assure that proposed construction will be reasonably safe from flooding. The test of reasonableness is a local 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 insurance rates.
(Ord. 93-18 § 5.1.5, 1993; Ord. 2001-03; Ord. 2021-010, 2021)
1.
If a project will alter the BFE or boundaries of the SFHA, then the project proponent shall provide the community with engineering documentation and analysis regarding the proposed change.
2.
If a CLOMR application is made, then the project proponent shall also supply the full CLOMR documentation package to the Floodplain Administrator to be attached to the floodplain development permit, including all required property owner notifications.
(Ord. 2021-010, 2021)
In all areas of special flood hazards where base flood elevation data has been provided as set forth in KCC § 14.08.040, Basis for establishing the areas of special flood hazard, or KCC § 14.08.120, Use of other base flood data, the following provisions are required.
(Ord. 93-18 § 5.2, 1993; Ord. 200103; Ord. 2021-010, 2021)
1.
In AE and A1-30 zones, or other A zoned areas where the BFE has been determined or can be reasonably obtained, new construction, substantial improvement, and reconstruction due to substantial damage of any residential structure shall have the lowest floor, including basement, elevated one foot or more above the base flood elevation.
2.
Fully enclosed areas below the lowest floor that are subject to flooding are prohibited, or if used solely for parking access or storage shall be designed to automatically equalize hydrostatic and hydrodynamic flood forces on exterior walls by allowing for the entry and exit of floodwaters. Designs for meeting this requirement must either be certified by a registered professional engineer or architect or 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.
c.
Openings may be equipped with screens, louvers, or other coverings or devices provided that they permit the automatic entry and exit of floodwaters.
d.
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.
e.
Because of hydrodynamic loads, below grade crawlspace construction is not permitted in areas with flood velocities greater than 5 feet per second unless the design is approved by a registered architect or licensed engineer.
3.
Any interior or exterior building utility systems must be elevated one-foot or more above the Base Flood Elevation (BFE) with the exception of utility meters and equipment specifically designed to withstand inundation according to the standards of the International Residential Codes and the NFIP.
4.
Portions of buildings below the BFE must be constructed using methods and practices that minimize flood damages, and with materials resistant to flood damage. This includes any joists, pony walls, beams, posts, insulation, wall coverings, wall sheathing or other materials that extend below the BFE.
5.
The elevation of the interior crawlspace grade (inside of the foundation walls in crawlspace construction) must be at or above the lowest elevation of the exterior grade. Below-grade crawlspace foundations will be allowed only if all of the following conditions are met, in addition to the minimum criteria set forth above in this subsection: (buildings that have below-grade crawlspaces may have higher flood insurance premiums than buildings that have the preferred crawlspace construction, with the interior elevation at or above the lowest adjacent exterior grade).
a.
The interior grade of the crawlspace (below the BFE) must not be more than 2 feet below the lowest adjacent exterior grade.
b.
The height of the below-grade crawlspace, measured from the interior grade of the crawlspace to the top of the crawlspace foundation wall must not exceed 4 feet at any point.
c.
There must be an adequate drainage system that removes floodwaters from the interior of the crawlspace. Possible options include natural drainage through porous, well drained soils and drainage systems such as perforated pipes, drainage tiles, gravel or crushed stone drainage by gravity, or mechanical means.
d.
The velocity of floodwaters at the site should not exceed five (5) feet per second for any crawlspace.
6.
Garages attached to a residential structure must have the floor elevated above the BFE or be constructed according to the following conditions:
a.
The walls must have openings designed to automatically equalize hydrostatic and hydrodynamic flood forces by allowing for the entry and exit of floodwaters. (See the requirements listed above for the residential structure per 14.08.250).
b.
All portions of the garage below the BFE must be constructed with materials resistant to flood damage. This includes any studs, walls, beams, posts, insulation, wall coverings, wall sheathing or other materials that extend below the BFE.
c.
Any utility systems within the garage must be elevated one foot or more above the Base Flood Elevation (BFE) with the exception of utility meters and equipment specifically designed to withstand inundation according to the standards of the International Residential Codes and the NFIP.
d.
New construction, substantial improvement and reconstruction due to substantial damage of any residential structure in an AO zone shall meet the requirements in KCC § 14.08.310.
e.
New construction and substantial improvement of any residential structure 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.
(Ord. 93-18 § 5.2.1, 1993; Ord. 2001-03; Ord. 2007-22, 2007; Ord. 2007-34, 2007; Ord. 2014-015, 2014; Ord. 2021-010, 2021)
The following special provisions apply only to detached accessory structures used as garages or small storage sheds to single-family residences.
1.
Detached accessory structures shall have the lowest floor elevated above the base flood elevation. When an accessory structure investment is not larger than a one-story and 600 square feet, the structure need not be elevated. However, the structure must have openings to allow floodwater in and out as required by KCC § 14.08.250(2) and be constructed using flood resistant materials below the BFE.
2.
For floodplain management purposes, accessory structures shall not be used for human habitation and must be limited to parking and storage.
3.
Accessory structures shall comply with the foundation opening requirements in KCC § 14.08.250(2).
4.
Accessory structures shall be constructed and placed on the building site so as to offer the minimum resistance to the flow of floodwaters.
5.
Accessory structures must be adequately anchored to prevent flotation, collapse, or lateral movement of the structure which may result in damage to other structures.
7.
Service facilities such as electrical and heating equipment shall be elevated one foot or more abovethe base flood elevation.
8.
If the structure is converted to another use, it must be brought into full compliance with the standards governing this ordinance.
9.
Detached garages, storage structures, and other accessory structures not meeting the above standards must be constructed in accordance with all applicable standards in Section 14.08.250.
10.
Upon completion of the structure, certification that the requirement of this section have been satisfied shall be provided to the Floodplain Administrator for verification.
11.
Applicants that elect not to elevate the lowest floor of accessory structures under the provisions of this section shall be notified that flood insurance premium rates may be increased as a result of this practice. The applicant shall be aware that flood insurance rates may be increased as a result of this practice, and a note stating such shall be included in the issuance of related permits.
(Ord. 93-18 § 5.2.2, 1993; Ord. 2001-03; Ord. 2007-22, 2007; Ord. 2007-34, 2007; O-2012-009, 2012; Ord. 2014-015, 2014; Ord. 2021-010, 2021; Ord. 2023-010, 2023)
New construction and substantial improvement of any commercial, industrial or other nonresidential structures, except detached accessory structures, shall either have the lowest floor, including basement, elevated one foot or more above the base flood elevation; or, together with attendant utility and sanitary facilities, shall meet requirements of subsection 1 or 2, below:
1.
New construction, substantial improvement, and reconstruction due to substantial damage of any commercial, industrial or other nonresidential structure shall meet all of the following requirements:
a.
In AE and A1-30 zones or other A zoned areas where the BFE has been determined or can be reasonably obtained:
New construction and substantial improvement of any commercial, industrial, or other nonresidential structure shall have the lowest floor, including basement, elevated one foot or more above the BFE, or elevated as required by ASCE 24, whichever is greater. Mechanical equipment and utilities shall be waterproofed or elevated at least one foot above the BFE, or as required by ASCE 24, whichever is greater.
b.
If located in an AO zone, the structure shall meet the requirements in Appendix A.
c.
If located in an Unnumbered A zone for which a BFE is not available and cannot be reasonably obtained, the structure 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.
Fully enclosed areas below the lowest floor that are subject to flooding are prohibited, or if used solely for parking, access or storage shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwaters. Designs for meeting this requirement must either be certified by a registered professional engineer or architect or must meet or exceed the following minimum criteria:
i.
Have a minimum of two openings with a total net area of not less than one square inch for every square foot of enclosed area subject to flooding.
ii.
The bottom of all openings shall be no higher than one foot above grade.
iii.
Openings may be equipped with screens, louvers, valves, or other coverings or devices provided that they permit the automatic entry and exit of floodwater.
iv.
A garage attached to a structure, constructed with the garage floor slab below the BFE, must be designed to allow for the automatic entry and exit of flood waters.
2.
If the requirements of subsection 1 are not met, then new construction and substantial improvement of any commercial, industrial or other nonresidential structure shall meet all of the following requirements:
a.
Be flood-proofed so that below one foot above the base flood level the structure is watertight with walls substantially impermeable to the passage of water or dry flood proofed 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.
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 subsection 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 KCC § 14.08.130(2).
d.
Nonresidential structures that are elevated, not flood-proofed, must meet the same standards for space below the lowest floor as described in KCC § 14.08.250(2).
Applicants flood-proofing nonresidential buildings shall be notified that flood insurance premiums will be based on rates that are one foot below the flood-proofed level. |
(Ord. 93-18 § 5.2.3, 1993; Ord. 2001-03; Ord. 2021-010, 2021)
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. 2021-010, 2021)
Construction of new, critical facilities shall be located outside the limits of the special flood hazard area. However, new construction and substantial improvement of both new and existing critical facilities shall be permissible within the 100-year floodplain, provided no feasible alternative site is available, and provided the facility's nature is related to or necessitates a riverine location (such as municipal water and sewer pump stations and related treatment facilities).
1.
Critical facilities shall have the lowest floor elevated three feet or more above the base flood elevation or the height of the 500-year flood, whichever is higher; and
2.
Flood-proofing and sealing measures must be taken to ensure that toxic substances will not be displaced by or released into floodwaters; and
3.
Access routes to critical facilities shall be elevated to or above the base flood elevation to the extent possible.
(Ord. 93-18 § 5.2.4, 1993; Ord. 2001-03; Ord. 2012-009, 2012)
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. 2021-010, 2021)
1.
All manufactured homes to be placed or substantially improved on sites shall be elevated on a permanent foundation such that the lowest floor of the manufactured home is elevated one foot or more above the base flood elevation and be securely anchored to an adequately anchored foundation system to resist flotation, collapse and lateral movement.
2.
Any interior or exterior building utility systems must be elevated one-foot or more above the Base Flood Elevation (BFE) with the exception of utility meters and equipment specifically designed to withstand inundation according to the standards of the International Residential Codes and the NFIP.
(Ord. 93-18 § 5.2.5, 1993; Ord. 2001-03; 2007-34, 2007; Ord. 2012-009, 2012; Ord. 2021-010, 2021)
1.
Recreational vehicles shall not be placed in a special flood hazard area from January 1st until the Wednesday before Memorial Day and again from November 15th through December 31st. The prohibition shall be inclusive of the end date of each period. An RV placed before the prohibited period shall not remain after November 14th; and
Exception: This regulation shall not be interpreted to prevent recreational use of property, but shall prohibit the unattended storage of all recreational vehicles and equipment during the flood season as outlined in 14.08.295 (1). If a notice of correction is placed upon the Recreational Vehicle and such notice is observed upon such Recreational Vehicle over 72 hours later, such observation shall create a rebuttable presumption of unattended storage. Such notice must reference that failure to remove it will create the before stated presumption.
Exception: Lawfully established, conditionally permitted uses (CUPs) such as campgrounds and recreational parks in existence prior to the adoption of this ordinance shall be allowed to continue their approved operations provided such uses are not dangerous to life and property and have and continue to comply with the laws and regulation as they existed at the time the CUP was issued. Such uses shall not be expanded and must comply with all rules and regulations regarding nonconforming uses.
2.
3.
Park Model Trailers as defined in KCC § 14.04.045 shall not be placed in a flood hazard area.
Exception: to 1, 2, and 3 above. A recreational vehicle or Park Model Trailer being used as a primary residence and located in manufactured/mobile home community as defined in RCW 59.20.030 that was in existence before June 8, 2008 is exempted from the restrictions found in subsections 1, 2, and 3 above. The placement of such recreational vehicle or Park Model Trailer requires both a permit under KCC § 17.92.020 and engineering to address the flood hazard. Additionally, such placement shall be conditioned upon meeting all the requirements placed upon a mobile and/or manufacture home in the same location. |
(Ord. 200103; Ord. 2009-25, 2009; Ord. 2014-015, 2014; Ord. 2021-010, 2021)
Located within areas of special flood hazard established in KCC § 14.08.040 are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of floodwaters which carry debris and potential projectiles, and erosion potential, the following provisions apply:
1.
Prohibit encroachments, including fill, new construction, substantial improvements, and other development, 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 encroachment would 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 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 of a structure to correct existing violations of state or local health, sanitary, or safety codes which have been identified by the local code enforcement official and which are the minimum necessary to assure safe living conditions or to structures identified as historic places shall not be included in the 50 percent.
3.
If subsection (1) of this section is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of KCC § 14.08.180 through § 14.08.310, provisions for flood hazard reduction, except for construction and reconstruction of residential structures that is prohibited by subsection (2) of this section.
4.
Traditional agricultural practices are exempt.
(Ord. 93-18 § 5.3, 1993; Ord. 2001-03; Ord. 2007-22, 2007; Ord. 2007-34, 2007; Ord. 2012-009, 2012; Ord. 2013-008, 2013; Ord. 2014-015, 2014; Ord. 2021-010, 2021)
See KCC Title 17A.
(Ord. 93-18 § 5.4, 1993; Ord. 2001-03)
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 these areas, the following provisions apply:
1.
New construction, substantial improvements, and reconstruction due to substantial damage of residential structures and manufactured homes within AO Zones:
a.
Shall have the lowest floor (including basements) elevated above the highest grade adjacent to the building, one foot or more above the depth number specified in feet on the FIRM (at least two feet above the highest adjacent grade to the structure if no depth number is specified).
b.
Any interior or exterior building utility systems must be elevated one-foot or more above the depth number specified in feet on the FIRM (at least two feet above the highest adjacent grade to the structure if no depth number is specified)with the exception of utility meters and equipment specifically designed to withstand inundation according to the standards of the International Residential Codes and the NFIP.
2.
New construction and substantial improvements of nonresidential structures within AO Zones shall either:
a.
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
b.
Together with attendant utility and sanitary facilities, be completely flood-proofed 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 as in KCC § 14.08.270(3).
3.
Require adequate drainage paths around structures on slopes to guide floodwaters around and away from proposed structures.
4.
Recreational vehicles placed on sites within AO zones on the community’s FIRM either:
a.
Be on the site for fewer than 180 consecutive days, or
b.
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
c.
Meet the requirements of subsections (1) and (3) above and the anchoring requirements for manufactured homes [Section 14.08.190(2)].
(Ord. 93-18 § 5.5, 1993; Ord. 2001-03; Ord. 2009-25, 2009; Ord. 2014-015, 2014; Ord. 2021-010, 2021)
Filling, grading or other activity that would reduce the effective storage volume shall be mitigated by creating compensatory storage on-site, or off-site if legal arrangements can be made, to assure that the effective compensatory storage volume will be preserved over time; provided, however, that no increased upstream or downstream flood hazard shall be created by any fill authorized in the floodplain by this chapter or other applicable chapters.
(Ord. 2011-013, 2011)
In areas with base flood elevations (but a regulatory flood way 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 county'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. 2012-009, 2012; Ord. 2021-010, 2021)