Chapter 16.46
FLOOD HAZARD AREA REGULATIONS

Sections:

16.46.010    Statement of purpose.

16.46.020    Definitions.

16.46.030    General provisions.

16.46.040    Administration.

16.46.050    Provisions for flood hazard protection.

16.46.060    Severability.

16.46.010 Statement of purpose.

A. It is the purpose of this legislation to promote the public health, safety, and general welfare, and to avoid or abate public nuisances, and to minimize public and private losses due to flood conditions in specific areas by provisions designed to:

1. Protect human life and health;

2. Minimize expenditure of public money and costly flood control projects;

3. Minimize the need for rescue and relief efforts associated with flooding and generally undertaken at the expense of the general public;

4. Minimize prolonged business interruptions;

5. Minimize damage to public facilities and utilities such as water and gas mains, electric, telephone and sewer lines, streets, and bridges located in areas of special flood hazard;

6. Help maintain a stable tax base by providing for the sound use and development of areas of special flood hazard so as to minimize future flood blight areas;

7. Ensure that potential buyers are notified that property is in an area of special flood hazard; and

8. Ensure that those who occupy the areas of special flood hazard assume responsibility for their actions.

B. Methods of Reducing Flood Losses. In order to accomplish its purposes, this legislation includes 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 or in 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 waters;

4. Controlling filling, grading, dredging, and other development which may increase flood damage; and

5. Preventing or regulating the construction of flood barriers which will unnaturally divert flood waters or which may increase flood hazards in other areas. (Ord. 3370 § 2, 2020; Ord. 3285 § 2, 2018; Ord. 2045 § 7, 1995; Ord. 1462 § 1, 1985)

16.46.020 Definitions.

Unless specifically defined below, words or phrases used shall be interpreted so as to give them the meaning they have in common usage and to give this legislation its most reasonable application.

“Alteration of watercourse” means any action that will change the location of the channel occupied by water within the banks of any portion of a riverine water body.

“Appeal” means a request for a review of the director of public works’ interpretation of any provision in this chapter or a request for a variance.

“Appeal board” means a three-member board appointed by the mayor to hear and determine appeals.

“Area of shallow flooding” means a designated AO or AH zone on the flood insurance rate map (FIRM). The base flood depths range from one to three feet; a clearly defined channel does not exist; the path of flooding is unpredictable and indeterminate; and, velocity flow may be evident. AO is characterized as sheet flow, and AH indicates ponding.

“Area of special flood hazard” means the land in the floodplain within a community subject to a one percent or greater chance of flooding in any given year. Designation on maps always includes the letter “A” or “V.”

“Base flood” means the flood having a one percent chance of being equaled or exceeded in any given year (also referred to as the “100-year flood”).

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

“Breakaway wall” means a wall that is not part of the structural support of the building and is intended through its design and construction to collapse under specific lateral loading forces, without causing damage to the elevated portion of the building or supporting foundation system.

“Coastal high hazard area” means an area of special flood hazard extending from offshore to the inland limit of a primary frontal dune along an open coast and any other area subject to high velocity wave action from storms or seismic sources.

“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.

“Development” means any manmade change to improved or unimproved real estate, including but not limited to buildings or other structures, mining, dredging, filling, grading, paving, excavation or drilling operations, or storage of equipment or materials located within the area of special flood hazard.

“Elevated building” means, for insurance purposes, a nonbasement building which has its lowest elevated floor raised above ground level by foundation walls, shear walls, posts, piers, pilings, or columns.

“Existing manufactured home park or subdivision” means a manufactured home park or subdivision for which the construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including, at a minimum, the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads) is completed before the effective date of the adopted floodplain management regulations.

“Expansion to an existing manufactured home park or subdivision” means the preparation of additional sites by the construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads).

“Flood” or “flooding” means:

1. A general and temporary condition of partial or complete inundation of normally dry land areas from:

a. The overflow of inland or tidal waters;

b. The unusual and rapid accumulation of runoff of surface waters from any source; and/or

c. Mudslides (i.e., mudflows) which are proximately caused by flooding as defined in subsection (1)(b) of this definition and are akin to a river of liquid and flowing mud on the surfaces of normally dry land areas, as when earth is carried by a current of water and deposited along the path of the current.

2. The collapse or subsidence of land along the shore of a lake or other body of water as a result of erosion or undermining caused by waves or currents of water exceeding anticipated cyclical levels or suddenly caused by an unusually high water level in a natural body of water, accompanied by a severe storm, or by an unanticipated force of nature, such as flash flood or an abnormal tidal surge, or by some similarly unusual and unforeseeable event which results in flooding as defined in subsection (1)(a) of this definition.

“Flood elevation study” means the examination, evaluation and determination of flood hazards and, if appropriate, corresponding water surface elevations, or an examination, evaluation and determination of mudslide (i.e., mudflow) and/or flood-related erosion hazards. Also known as “flood insurance study (FIS).”

“Flood insurance rate map (FIRM)” means the official map on which the Federal Insurance Administrator has delineated both the areas of special flood hazards and the risk premium zones applicable to the community.

“Floodplain” or “flood prone area” means any land area susceptible to being inundated by water from any source. See “Flood” or “flooding.”

“Floodplain administrator” means the community official designated by title to administer and enforce the floodplain management regulations.

“Floodproofing” means any combination of structural and nonstructural additions, changes, or adjustments to structures which reduce or eliminate risk of flood damage to real estate or improved real property, water and sanitary facilities, structures, and their contents. Floodproofed structures are those that have the structural integrity and design to be impervious to flood water below the base flood elevation.

“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 a designated height.

“Functionally dependent use” means a use which cannot perform its intended purpose unless it is located or carried out in close proximity to water. The term includes only docking facilities, port facilities that are necessary for the loading and unloading of cargo or passengers, and ship building and ship repair facilities, and does not include long-term storage or related manufacturing facilities.

“Highest adjacent grade” means the highest natural elevation of the ground surface prior to construction next to the proposed walls of a structure.

“Historic structure” means any structure that is:

1. Listed individually in the National Register of Historic Places (a listing maintained by the Department of the Interior) or preliminarily determined by the Secretary of the Interior as meeting the requirements for individual listing on the National Register;

2. Certified or preliminarily determined by the Secretary of the Interior as contributing to the historical significance of a registered historic district or a district preliminarily determined by the Secretary to qualify as a registered historic district;

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

4. Individually listed on a local inventory of historic places in communities with historic preservation programs that have been certified either:

a. By an approved state program as determined by the Secretary of the Interior; or

b. Directly by the Secretary of the Interior in states without approved programs.

“Lowest floor” means the lowest floor of the lowest enclosed area (including basement). An unfinished or flood-resistant enclosure, usable solely for parking of vehicles, building access or storage, in an area other than a basement area, is not considered a building’s lowest floor; provided, that such enclosure is not built so as to render the structure in violation of the applicable nonelevation design requirements of this chapter found at LMC 16.46.050(B)(1)(b).

“Manufactured home” means a structure, transportable in one or more sections, which is built on a permanent chassis and is designed for use with or without a permanent foundation when connected to the required utilities. For floodplain management purposes, the term “manufactured home” also includes park trailers, travel trailers, and other similar vehicles placed on a site for greater than 180 consecutive days. For insurance purposes the term “manufactured home” does not include park trailers, travel trailers, and other similar vehicles. The term “manufactured home” does not include a recreational vehicle.

“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.

“Mean sea level” means, for purposes of the National Flood Insurance Program, the vertical datum to which base flood elevations shown on a community’s flood insurance rate map are referenced.

“New construction” means, for the purpose of determining insurance rates, structures for which the start of construction commenced on or after the effective date of an initial flood insurance rate map or after December 31, 1974, whichever is later, and includes any subsequent improvements to such structures. For floodplain management purposes, “new construction” means structures for which the start of construction commenced on or after the effective date of a floodplain management regulation adopted by a community and includes any subsequent improvements to such structures.

“New manufactured home park or subdivision” means a manufactured home park or subdivision for which the construction of facilities for servicing the 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.

“Recreational vehicle” means a vehicle which is:

1. Built on a single chassis;

2. Four hundred square feet or less when measured at the largest horizontal projection;

3. Designed to be self-propelled or permanently towable by a light duty truck; and

4. Designed primarily not for use as a permanent dwelling but as temporary living quarters for recreational, camping, travel, or seasonal use.

“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 was 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 slab or footings, the installation of piles, the construction of columns, or any work beyond the stage of excavation; or the placement of a manufactured home on a foundation. Permanent construction does not include land preparation, such as clearing, grading, and filling; nor does it include the installation of streets and/or walkways; nor does it include excavation for a basement, footings, piers, or foundations, or the erection of temporary forms; nor does it include the installation on the property of accessory buildings, such as garages or sheds not occupied as dwelling units or not as part of the main structure. For a substantial improvement, the “actual start of construction” means the first alteration or any wall, ceiling, floor, or other structural part of a building, whether or not that alteration affects the external dimensions of the building.

“Structure” means a walled and roofed building or manufactured home including a gas or liquid storage tank that is principally above ground.

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

“Substantial improvement” means any reconstruction, rehabilitation, addition or improvement of a structure, the cost of which equals or exceeds 50 percent of the market value of the structure before the start of construction of the improvement. This term includes structures which have incurred substantial damage, regardless of the actual repair work performed. The term does not, however, include either:

1. Any project for improvement of a structure to correct existing violations of state or local health, sanitary, or safety code specifications that have been previously identified by the local code enforcement official and which are the minimum necessary to assure safe living conditions; or

2. Any alteration of a historic structure; provided, that the alteration will not preclude the structure’s continued designation as a historic structure.

“Variance” means a grant of relief from the requirements of this legislation which permits construction in a manner that would otherwise be prohibited by this chapter.

“Water dependent” means a structure for commerce or industry which cannot exist in any other location and is dependent on the water by reason of the intrinsic nature of its operations. (Ord. 3370 § 2, 2020; Ord. 3285 § 2, 2018; Ord. 2274 § 1, 1999; Ord. 1916 § 1, 1992; Ord. 1701 § 1, 1989; Ord. 1462 § 2, 1985)

16.46.030 General provisions.

A. Lands to Which This Chapter Applies. This legislation shall apply to all areas of special flood hazards within the jurisdiction of the city of Lynnwood.

B. Basis for Establishing the Areas of Special Flood Hazard. The areas of special flood hazard identified by the Federal Insurance Administrator in a scientific and engineering report entitled “The Flood Insurance Study for Snohomish County, Washington and Incorporated Areas,” dated June 19, 2020, as amended, with accompanying flood insurance rate maps as amended, are hereby adopted by reference and declared to be part of this chapter. The flood insurance study and the flood insurance rate map are on file at the city of Lynnwood public works department. The best available information for flood hazard area identification as outlined in LMC 16.46.040(C)(2) shall be the basis for regulation until a new FIRM is issued which incorporates the data utilized under LMC 16.46.040(C)(2).

C. Penalties for Noncompliance. No structure or land shall hereafter be constructed, located, extended, converted, or altered without full compliance with the terms of this chapter and other applicable regulations. Violation of the provisions of this chapter by failure to comply with any of its requirements (including 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 upon conviction thereof be fined not more than $500.00 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 of Lynnwood from taking such lawful action as is necessary to prevent or remedy any violation.

D. Abrogation and Greater Restrictions. This legislation is not intended to repeal, abrogate, or impair any existing easements, covenants, or deed restrictions. However, where this chapter and another ordinance, easement, covenant, or deed restriction conflict or overlap, whichever imposes the more stringent restrictions shall prevail.

E. Interpretation. In the interpretation and application of this legislation, 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 law.

F. Warning and Disclaimer of Liability. The degree of flood protection required by this chapter is considered reasonable for regulatory purposes and is based on scientific and engineering considerations. Larger floods can and will occur on rare occasions. Flood heights may be increased by manmade or natural causes. This legislation does not imply that land outside the areas of special flood hazards or uses permitted within such areas will be free from flooding or flood damages. This legislation shall not create liability on the part of the city of Lynnwood, any officer or employee thereof, or the Federal Insurance Administration, for any flood damages that result from reliance on this legislation or any administrative decision lawfully made thereunder. (Ord. 3370 § 2, 2020; Ord. 3285 § 2, 2018; Ord. 2274 § 2, 1999; Ord. 1916 § 2, 1992; Ord. 1701 § 2, 1989; Ord. 1462 § 3, 1985)

16.46.040 Administration.

A. Establishment of Development Permit.

1. Development Permit Required. A development permit shall be obtained before construction or development begins within any area of special flood hazard established in LMC 16.46.030(B). The permit shall be for all structures including manufactured homes, as set forth in LMC 16.46.020, Definitions, and for all development including fill and other activities, also as set forth in LMC 16.46.020, Definitions.

2. Application for Development Permit. Application for a development permit shall be made on forms furnished by the city of Lynnwood 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 or materials, drainage facilities, and the location of the foregoing. Specifically, the following information is required:

a. Proposed elevation in relation to mean sea level, of the lowest floor (including basement) of all structures;

b. Proposed elevation in relation to mean sea level to which any structure will be floodproofed;

c. Certification by a registered professional engineer or architect that the floodproofing methods for any nonresidential structure meet the floodproofing criteria in LMC 16.46.050(B)(2); and

d. Description of the extent to which a watercourse will be altered or relocated as a result of proposed development.

B. Designation of the Public Works Director. The city director of public works or his designee is hereby appointed to administer, implement and enforce this legislation by granting or denying development permit applications in accordance with its provisions.

C. Duties and Responsibilities of the Public Works Director. Duties of the director of public works shall include, but not be limited to:

1. Permit Review.

a. Review all development permits to determine that the permit requirements of this chapter have been satisfied;

b. Review all development permits to determine that all necessary permits have been obtained from those federal, state, or local governmental agencies from which prior approval is required;

c. Review all development permits to determine the site is reasonably safe from flooding;

d. Review all development permits to determine if the proposed development is located in the floodway. If located in the floodway, assure that the encroachment provisions of LMC 16.46.050(C)(1) are met.

2. Use of Other Base Flood Data. When base flood elevation data has not been provided in accordance with LMC 16.46.030(B), Basis for Establishing the Areas of Special Flood Hazard, the public works director shall obtain, review, and reasonably utilize any base flood elevation and floodway data available from a federal, state, or other source, in order to administer LMC 16.46.050(B), Specific Standards, and 16.46.050(C), Floodways.

3. Information to Be Obtained and Maintained.

a. Obtain and maintain the actual (as-built) elevation of the lowest floor, including basement, of all new or substantially improved structures, and whether or not the structure contains a basement;

b. For all new or substantially improved floodproofed structures:

i. Verify and record the actual elevation to which the structure was floodproofed;

ii. Maintain the floodproofing certifications required in subsection (A)(2)(c) of this section; and

c. Maintain for public inspection all records pertaining to the provisions of this legislation.

4. Alteration of Watercourses.

a. Notify adjacent communities and the Washington State Department of Ecology prior to any alteration or relocation of a watercourse, and submit evidence of such notification to the Federal Insurance Administrator;

b. Assure that the flood-carrying capacity of the altered or relocated portion of said watercourse is maintained.

5. Interpretation of FIRM Boundaries. Make interpretations where needed, as to exact location of the boundaries of the areas of special flood hazards (for example, where there appears to be a conflict between a mapped boundary and actual field conditions). The person contesting the location of the boundary shall be given a reasonable opportunity to appeal the interpretation as provided in subsection (D) of this section.

6. Base flood elevations may increase or decrease resulting from physical changes affecting flooding conditions. As soon as practicable, but not later than six months after the date such information becomes available, the floodplain administrator shall notify the Federal Insurance Administrator of the changes by submitting technical or scientific data in accordance with Volume 44 Code of Federal Regulations Section 65.3. Such a submission is necessary so that upon confirmation of those physical changes affecting flooding conditions, risk premium rates and floodplain management requirements will be based upon current data.

7. Notify the Federal Insurance Administrator in writing of acquisition, by means of annexation, incorporation or otherwise, of additional areas of jurisdiction.

D. Variance Procedure.

1. Appeal Board. The mayor shall appoint members to the three-member appeal board as needed. Members shall have the educational and mechanical background and experience to hear and determine appeals arising from this legislation.

a. The appeal board shall hear and decide appeals and requests for variances from the requirements of this legislation;

b. The appeal board shall hear and decide appeals when it is alleged there is an error in any requirement, decision or determination made by the director of public works in the enforcement of this legislation;

c. Those aggrieved by the decision of the appeal board may appeal such decision to the Snohomish County superior court as provided by law;

d. In passing upon such applications, the appeal board shall consider all technical evaluations, all relevant factors, standards specified in other sections of this legislation; and

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

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

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

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

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

vi. The availability of alternative locations for the proposed use which are not subject to flooding or erosion damage;

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

viii. The relationship of the proposed use to the comprehensive plan and floodplain management program for that area;

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

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

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

e. Generally, the only condition under which a variance may be issued is for new construction and substantial improvements to be erected on a lot of one-half acre or less in size contiguous to and surrounded by lots with existing structures constructed below the base flood level, providing items in subsections (D)(1)(d)(i) through (xi) of this section have been fully considered. As the lot size increases beyond the one-half acre, the technical justification required for issuing the variance increases;

f. Upon consideration of the factors of subsection (D)(1)(d) of this section and the purposes of this legislation, the appeal board may attach such conditions to the granting of variances as it deems necessary to further the purposes of this legislation;

g. The director of public works shall maintain the records of the appeal actions and report any variances to the Federal Insurance Administration upon request.

2. Conditions for Variances.

a. Generally, the only condition under which a variance from the elevation standard may be issued is for new construction and substantial improvements to be erected on a lot of one-half acre or less in size contiguous to and surrounded by lots with existing structures constructed below the base flood level, providing items in subsections (D)(1)(d)(i) through (xi) of this section have been fully considered. As the lot size increases, the technical justification required for issuing the variance increases;

b. Variances may be issued for the repair, rehabilitation, or restoration of historic structures upon a determination that the proposed repair or rehabilitation will not preclude the structure’s continued designation as a historic structure and the variance is the minimum necessary to preserve the historic character and design of the structure;

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

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

e. Variance shall only be issued upon:

i. A showing of good and sufficient cause;

ii. A determination that failure to grant the variance would result in exceptional hardship to the applicant;

iii. A determination that the granting of a variance will not result in increased flood heights, additional threats to public safety, extraordinary public expense, create nuisances, cause fraud on or victimization of the public or conflict with existing local laws or ordinances;

f. Variances as interpreted in the National Flood Insurance Program are based on the general zoning law principle that they pertain to a physical piece of property; they are not personal in nature and do not pertain to the structure, its inhabitants, economic or financial circumstances. They primarily address small lots in densely populated residential neighborhoods. As such, variances from the flood elevations should be quite rare;

g. Variances may be issued for nonresidential buildings in very limited circumstances to allow a lesser degree of floodproofing than watertight or dry-floodproofing, where it can be determined that such action will have low damage potential, complies with all other variance criteria except subsection (D)(2)(a) of this section, and otherwise complies with LMC 16.46.050(A) and (B);

h. Any applicant to whom a variance is granted shall be given written notice over the signature of a community official that the issuance of a variance to construct a structure with a lowest floor elevation below the base flood elevation will result in increased premium rates for flood insurance up to amounts as high as $25.00 for $100.00 of insurance coverage and that such construction below the BFE increases risks to life and property. (Ord. 3370 § 2, 2020; Ord. 3285 § 2, 2018; Ord. 2274 § 3, 1999; Ord. 1701 § 3 – 7, 1989; Ord. 1462 § 4, 1985)

16.46.050 Provisions for flood hazard protection.

A. General Standards. In all areas of special flood hazards, the following standards are required:

1. Anchoring.

a. All new construction and substantial improvements 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 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.)

2. Construction Materials and Methods.

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. 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.

3. Utilities.

a. All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of flood waters into the system;

b. Water wells shall be located on high ground that is not in the floodway;

c. 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; and

d. On-site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding.

4. Development Proposals.

a. All development proposals, including subdivisions and manufactured home parks, shall be consistent with the need to minimize flood damage;

b. All development proposals, including subdivisions and manufactured home parks, shall have public utilities and facilities such as sewer, gas, electrical, and water systems located and constructed to minimize flood damage;

c. All development proposals, including subdivisions and manufactured home parks, shall have adequate drainage provided to reduce exposure to flood damage; and

d. Where base flood elevation data has not been provided or is not available from another authoritative source, it shall be generated for all development proposals, including subdivisions and manufactured home parks, greater than 50 lots or five acres (whichever is the lesser).

5. Review of Building Permits. Where elevation data is not available, either through the flood insurance study or from another authoritative source, LMC 16.46.040(C)(2), applications for building permits shall be reviewed to assure that proposed construction will be reasonably safe from flooding. The test of reasonableness is a local judgment and includes 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.

B. Specific Standards. In all areas of special flood hazards where base flood elevation data has been provided as set forth in LMC 16.46.030(B), Basis for Establishing the Areas of Special Flood Hazard, or LMC 16.46.040(C)(2), Use of Other Base Flood Data, the following provisions are required:

1. Residential Construction.

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

b. 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 flood waters. 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. 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.

ii. The bottom of all openings shall be no higher than one foot above grade.

iii. Openings may be equipped with screens, louvers, or other coverings or devices; provided, that they permit the automatic entry and exit of flood waters.

2. Nonresidential Construction. New construction and substantial improvement of any commercial, industrial or other nonresidential structure shall either have the lowest floor, including basement, elevated to the level of one foot or more above the base flood elevation; or, 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;

c. Be certified by a registered professional engineer or architect that the design and methods of construction are in conformance 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 LMC 16.46.040(C)(3)(b);

d. Nonresidential structures that are elevated, not floodproofed, must meet the same standards for space below the lowest floor as described in subsection (B)(1)(b) of this section;

e. Applicants floodproofing nonresidential buildings shall be notified that flood insurance premiums will be based on rates that are one foot below the floodproofed level (e.g., a building floodproofed to one foot above the base flood level will be rated as at the base flood level).

3. Critical Facility. Construction of new critical facilities shall be, to the extent possible, located outside the limits of the base floodplain. Construction of new critical facilities shall be permissible within the base floodplain if no feasible alternative site is available. Critical facilities constructed within the base floodplain shall have the lowest floor elevated to 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. Access routes elevated to or above the level of the base floodplain shall be provided to all critical facilities to the extent possible.

4. Manufactured Homes. 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.

a. All manufactured homes to be placed or substantially improved on sites:

i. Outside of a manufactured home park or subdivision;

ii. In a new manufactured home park or subdivision;

iii. In an expansion to an existing manufactured home park or subdivision; or

iv. 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 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 designed foundation system to resist flotation, collapse and lateral movement.

b. 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 be elevated so that either:

i. The lowest floor of the manufactured home is elevated one foot or more above the base flood elevation; or

ii. 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 be securely anchored to an adequately designed foundation system to resist flotation, collapse, and lateral movement.

5. Recreation Vehicles. Recreational vehicles placed on sites are required to either:

a. Be on the site for fewer than 180 consecutive days;

b. Be fully licensed and ready for highway use, on their wheels or jacking system, be attached to the site only by quick disconnect type utilities and security devices, and have no permanently attached additions; or

c. Meet the requirements of subsection (B)(4) of this section and the elevation and anchoring requirements for manufactured homes.

C. Floodways. Located within areas of special flood hazard established in LMC 16.46.030(B) are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of flood waters which carry debris, 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 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 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 code specifications 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 (C)(1) of this section is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of this section, Provisions for flood hazard reduction.

D. Wetlands Management. To the maximum extent possible, avoid the short- and long-term adverse impacts associated with the destruction or modification of wetlands, especially those activities which limit or disrupt the ability of the wetland to alleviate flooding impacts. The following process should be implemented:

1. Review proposals for development within base floodplains for their possible impacts on wetlands located within the floodplain.

2. Ensure that development activities in or around wetlands do not negatively affect public safety, health, and welfare by disrupting the wetlands’ ability to reduce flood and storm drainage.

3. Request technical assistance from the Department of Ecology in identifying wetland areas. Existing wetland map information from the National Wetlands Inventory (NWI) can be used in conjunction with the community’s FIRM to prepare an overlay zone indicating critical wetland areas deserving special attention.

E. AE Zones with Base Flood Elevations but No Floodways. In areas with base flood elevations (but a regulatory floodway has not been designated), no new construction, substantial improvements, or other development (including fill) shall be permitted within zone 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.

F. Zone VE Standards. New structures, substantial improvements and recreational vehicles shall meet the following provisions:

1. All new construction and substantial improvements in zone VE on the community’s FIRM shall be elevated on pilings and columns so that:

a. Elevation.

i. Residential Buildings. The bottom of the lowest horizontal structural member of the lowest floor (excluding the pilings or columns) is elevated one foot or more above the base flood level.

ii. Nonresidential Buildings. The bottom of the lowest horizontal structural member of the lowest floor (excluding the pilings or columns) is elevated one foot or more above the base flood level or meets the elevation requirements of ASCE 24, whichever is higher; 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 and water loads acting simultaneously on all building components. Wind and water loading values shall each have a one percent chance of being equaled or exceeded in any given year (100-year mean recurrence interval).

c. A registered professional engineer or architect 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 subsections (F)(1)(a)(i) and (ii) of this section.

2. Obtain 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 zone VE on the community’s FIRM and whether or not such structures contain a basement. The floodplain administrator shall maintain a record of all such information.

3. All new construction within zone VE on the community’s FIRM shall be located landward of the reach of mean high tide.

4. Provide that all new construction and substantial improvements within zone VE on the community’s FIRM have the space below the lowest floor either free of obstruction or constructed with nonsupporting breakaway walls, open wood latticework, 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 10 and no more than 20 pounds per square foot. Use of breakaway walls which exceed a design safe loading resistance of 20 pounds per square foot (either by design or when so required by local or state codes) may be permitted only if a registered professional engineer or architect certifies that the design proposed meets the following conditions:

a. Breakaway wall collapse shall 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 shall not be subject to collapse, displacement, or other structural damage due to the effects of wind and water loads acting simultaneously on all building components (structural and nonstructural). Maximum wind and water loading values to be used in this determination shall each have a one percent chance of being equaled or exceeded in any given year (100-year mean recurrence interval).

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

5. Prohibit the use of fill for structural support of buildings within zone VE on the community’s FIRM.

6. Prohibit manmade alteration of sand dunes within zone VE on the community’s FIRM which would increase potential flood damage.

7. All manufactured homes to be placed or substantially improved within zone VE on the community’s FIRM 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 meet the standards of subsections (F)(1) through (6) of this section and manufactured homes placed or substantially improved on other sites in an existing manufactured home park or subdivision within zone VE on the FIRM shall meet the requirements of subsection (A)(4) of this section.

8. Recreational vehicles placed on sites within V or VE zones on the community’s FIRM shall 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, attached to the site only by quick disconnect type utilities and security devices, and have no permanently attached additions; or

c. Meet the requirements of subsections (F)(1) and (3) of this section and the anchoring requirements for manufactured homes (subsection (A)(1)(b) of this section). (Ord. 3370 § 2, 2020; Ord. 3285 § 2, 2018; Ord. 2274 § 4, 1999; Ord. 1701 § 8, 1989; Ord. 1462 § 5, 1985)

16.46.060 Severability.

If any section, clause, sentence, or phrase of this chapter is held to be invalid or unconstitutional by any court of competent jurisdiction, then said holding shall in no way affect the validity of the remaining portions of this chapter. (Ord. 3370 § 2, 2020)