Chapter 15.12
FLOOD DAMAGE PREVENTION

Sections:

15.12.010    Definitions.

15.12.020    Lands to which this chapter applies.

15.12.030    Basis for establishing the areas of special flood hazard.

15.12.040    Abrogation and greater restrictions.

15.12.050    Interpretation.

15.12.060    Liability.

15.12.070    Development permit required.

15.12.080    Development permit – Application.

15.12.090    Floodplain administrator – Designated.

15.12.100    Floodplain administrator – Duties and responsibilities.

15.12.110    Permit review.

15.12.120    Use of other base flood data.

15.12.130    Information to be obtained and maintained.

15.12.140    Alteration of watercourses.

15.12.150    Interpretation of FIRM boundaries.

15.12.160    Variance procedure – Appeal.

15.12.170    Condition of variances.

15.12.180    Flood hazard reduction provisions.

15.12.190    Anchoring.

15.12.200    Construction materials and methods.

15.12.210    Utilities.

15.12.220    Subdivision proposals.

15.12.230    Review of building permits.

15.12.240    Specific standards.

15.12.250    Residential construction.

15.12.260    Nonresidential construction.

15.12.270    Critical facility.

15.12.280    Manufactured homes.

15.12.290    Floodways.

15.12.300    Wetlands management.

15.12.310    Standards for shallow flooding areas (AO zones).

15.12.320    Coastal high hazard areas.

15.12.325    Recreational vehicles in A, AE, AO, V, and VE zones.

15.12.330    AE and A1-30 zones with base flood elevations but no floodways.

15.12.335    Construction of below-grade crawlspaces for buildings located in special flood hazard areas.

15.12.340    Violation and penalty.

Prior legislation: Ords. 649 and 640.

15.12.010 Definitions.

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

“Addition” means any activity that expands the enclosed footprint or increases the square footage of an existing structure.

“Appeal” means a request for a review of the floodplain administrator’s interpretation of any provision of this chapter or a request for a variance.

“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. Zone AO is characterized as sheet flow with average depths determined, and AH indicates ponding with base flood elevations determined.

“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 letters A or V.

“Base flood elevation (BFE)” means the elevation in relation to mean sea level (MSL) as determined by the flood insurance study and shown on the flood insurance rate map for Zones AE, AH, AR, AR/A, AR/AE, AR/AH, AR/AO, V1 – V30 and VE that indicates the water surface elevation resulting from a flood that has a one percent chance of equaling or exceeding that level in any given year.

“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 a 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 the area subject to high velocity waters, including, but not limited to, storm surge or tsunamis. The area is designated on the FIRM as Zones V1 – V30 and VE.

“Critical facility” is a structure or related infrastructure, but not the land on which it is situated, that if flooded may result in significant hazards to public health and safety or interrupt essential services and operations for the community at any time before, during and after a flood. Critical facilities include, but are not limited to, schools, nursing homes, hospitals, police, fire and emergency response installations, 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.

“Flood” or “flooding” means a general and temporary condition of partial or complete inundation of normally dry land areas from:

(A) The overflow of inland or tidal waters; and/or

(B) The unusual and rapid accumulation of runoff or surface waters from any source.

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

“Flood insurance study” means the official report provided by the Federal Insurance Administration that includes flood profiles, the flood boundary-floodway map, and the water surface elevation of the base flood.

“Floodplain administrator” means the individual appointed by the mayor to administer and implement this chapter by granting or denying floodplain development permit applications in accordance with its provisions.

“Floodway” means the channel of a river or other watercourse and the adjacent land areas that must be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation more than one foot.

“Freeboard” means the vertical distance, in feet, above the base flood elevation to which development must be elevated.

“Historic structure” means any structure that is:

(A) 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;

(B) 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;

(C) 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

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

(i) An approved state program as determined by the Secretary of the Interior; or

(ii) Directly by the Secretary of the Interior in states without approved programs.

“Letter of map amendment (LOMA)” means a letter from FEMA officially amending the effective national flood insurance rate map, which establishes that a property is not located in a FEMA SFHA.

“Letter of map change (LOMC)” means all letters of SFHA changes from FEMA including LOMR, LOMR-F, LOMA and physical map revisions (PMR).

“Letter of map revision based on fill (LOMR-F)” means a letter from FEMA stating that a structure or parcel of land that has been elevated by fill outside the existing regulatory floodway would not be inundated by the base flood.

“Letter of map revision (LOMR)” means a letter from FEMA officially revising the effective flood insurance rate map to show changes in zones, delineation and water surface elevation of floodplains and floodways.

“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 WMC 15.12.250(2).

“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.

“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.

“New construction” means structures for which the “start of construction” commenced on or after the effective date of the ordinance codified in this chapter.

“No-rise” means a calculated rise in flood depth of 0.00 feet as rounded to the nearest hundredth of a foot.

“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 a 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 foundation 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 part of the main structure.

“Structure” means a walled and roofed building 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 repair, reconstruction, or improvement of a structure, the cost of which equals or exceeds 50 percent of the market value of the structure either:

(A) Before the improvement or repair is started; or

(B) If the structure has been damaged and is being restored, before the damage occurred. For the purposes of this definition “substantial improvement” is considered to occur when the first alteration of any wall, ceiling, floor, or other structural part of the building commences, whether or not that alteration affects the external dimensions of the structure.

The term can exclude:

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

(B) Any alteration of a structure listed on the National Register of Historic Places or a State Inventory of Historic Places.

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

“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.

“Water well” means any excavation that is constructed when the intended use of the well is for the location, diversion, artificial recharge, observation, monitoring, dewatering or withdrawal of groundwater. Water wells include ground source heat pump borings and grounding wells. (Ord. 1598 §§ 1 – 13, 26, 2017; Ord. 1441 §§ 1 – 4, 2008; Ord. 844 § 1, 1989)

15.12.020 Lands to which this chapter applies.

This chapter shall apply to all areas of special flood hazards within the jurisdiction of the city. (Ord. 844 § 2.1, 1989)

15.12.030 Basis for establishing the areas of special flood hazard.

The areas of special flood hazard identified by the Federal Insurance Administration in a scientific and engineering report entitled “The Flood Insurance Study for Grays Harbor County and Incorporated Areas, Effective February 3, 2017,” with accompanying flood insurance rate maps (FIRM) and any revision thereto, is adopted by reference and declared to be a part of this chapter. The flood insurance study is on file at Westport City Hall, Westport, Washington. The best available information for flood hazard area identification shall be the basis for regulation until a new FIRM is issued that incorporates data utilized under WMC 15.12.120. (Ord. 1598 § 14, 2017; Ord. 1441 § 5, 2008; Ord. 844 § 2.2, 1989)

15.12.040 Abrogation and greater restrictions.

This chapter is not intended to repeal, abrogate or impair any existing easements, covenants or deed restrictions. However, where this chapter and another ordinance, easement, covenant or deed restriction conflict or overlap, whichever imposes the more stringent restrictions shall prevail. (Ord. 8.44 § 2.4, 1989)

15.12.050 Interpretation.

In the interpretation and application of this chapter, all provisions shall be:

(1) Considered as minimum requirements;

(2) Liberally construed in favor of the governing body; and

(3) Deemed neither to limit nor repeal any other powers granted under state statutes. (Ord. 844 § 2.5, 1989)

15.12.060 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 chapter 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 chapter shall not create liability on the part of the city, any officer or employee thereof, or the Federal Insurance Administration, for any flood damages that result from reliance on this chapter or any administrative decision lawfully made hereunder. (Ord. 1598 § 15, 2017; Ord. 844 § 2.6, 1989)

15.12.070 Development permit required.

A development permit shall be obtained before construction or development begins within any area of special flood hazard established in WMC 15.12.030. The permit shall be for all structures including manufactured homes, as set forth in WMC 15.12.010, and for all development including fill and other activities, also as set forth in WMC 15.12.010. (Ord. 844 § 3.1-1, 1989)

15.12.080 Development permit – Application.

Application for a development permit shall be made on forms furnished by the floodplain administrator and may include, but not be limited to, plans in duplicate drawn to scale showing the nature, location, dimensions and elevations of the area in question; existing or proposed structures, fill, storage of materials, drainage facilities and the location of the foregoing. Specifically, the following information is required:

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

(2) Elevation in relation to mean sea level to which any structure has been floodproofed;

(3) Certification by a registered professional engineer or architect that the floodproofing methods for any nonresidential structure meet the floodproofing criteria in WMC 15.12.260; and

(4) Description of the extent to which a watercourse will be altered or relocated as a result of proposed development. (Ord. 1598 § 26, 2017; Ord. 844 § 3.1-2, 1989)

15.12.090 Floodplain administrator – Designated.

The floodplain administrator is appointed to administer and implement this chapter by granting or denying development permit applications in accordance with its provisions. (Ord. 1598 § 26, 2017; Ord. 844 § 3.2, 1989)

15.12.100 Floodplain administrator – Duties and responsibilities.

Duties of the floodplain administrator shall include, but not be limited to, those set forth in WMC 15.12.110 through 15.12.150. (Ord. 1598 § 26, 2017; Ord. 844 § 3.3, 1989)

15.12.110 Permit review.

The floodplain administrator shall:

(1) Review all development permits to determine that the permit requirements of this chapter have been satisfied;

(2) 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. (Ord. 1598 §§ 16, 26, 2017; Ord. 844 § 3.3-1, 1989)

15.12.120 Use of other base flood data.

When base flood elevation data has not been provided in accordance with WMC 15.12.030, the floodplain administrator 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 WMC 15.12.240 through 15.12.290. (Ord. 1598 § 26, 2017; Ord. 844 § 3.3-2, 1989)

15.12.130 Information to be obtained and maintained.

The floodplain administrator shall:

(1) Where base flood elevation data is provided through the flood insurance study or required as in WMC 15.12.120, obtain and record the actual (as-built) elevation (in relation to mean sea level) of the lowest floor, including basement, of all new or substantially improved structures, and whether or not the structure contains a basement;

(2) For all new or substantially improved floodproofed structures:

(A) Verify and record the actual elevation and floodproofed elevation (in relation to mean sea level); and

(B) Maintain the floodproofing certifications required in WMC 15.12.080(3);

(3) Maintain for public inspection all records pertaining to the provisions of this chapter. (Ord. 1598 §§ 17, 26, 2017; Ord. 844 § 3.3-3, 1989)

15.12.140 Alteration of watercourses.

The floodplain administrator shall:

(1) 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 Administration;

(2) Require that maintenance is provided within the altered or relocated portion of said watercourse so that the flood-carrying capacity is not diminished. (Ord. 1598 § 26, 2017; Ord. 844 § 3.3-4, 1989)

15.12.150 Interpretation of FIRM boundaries.

The floodplain administrator shall 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 WMC 15.12.160. (Ord. 1598 § 26, 2017; Ord. 844 § 3.3-5, 1989)

15.12.160 Variance procedure – Appeal.

(1) The land use hearing examiner as established by the city shall hear and decide appeals and requests for variances from the requirements of this chapter.

(2) The land use hearing examiner shall hear and decide appeals when it is alleged there is an error in any requirement, decision or determination made by the floodplain administrator in the enforcement or administration of this chapter.

(3) Those aggrieved by the decision of the land use hearing examiner, or any taxpayer, may appeal such decision to the superior court of Grays Harbor County, as provided by law.

(4) In passing upon such applications, the land use hearing examiner shall consider all technical evaluations, all relevant factors, standards specified in other sections of this chapter, and:

(A) The danger that materials may be swept onto other lands to the injury of others;

(B) The danger to life and property due to flooding or erosion damage;

(C) The susceptibility of the proposed facility and its contents to flood damage and the effect of such damage on the individual owner;

(D) The importance of the services provided by the proposed facility to the community;

(E) The necessity to the facility of a waterfront location, where applicable;

(F) The availability of alternative locations for the proposed use which are not subject to flooding or erosion damage;

(G) The compatibility of the proposed use with existing and anticipated development;

(H) The relationship of the proposed use to the comprehensive plan and floodplain management program for that area;

(I) The safety of access to the property in times of flood for ordinary and emergency vehicles;

(J) The expected heights, velocity, duration, rate of rise, and sediment transport of the floodwaters and the effects of wave action, if applicable, expected at the site; and

(K) 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.

(5) Upon consideration of the factors of subsection (4) of this section and the purposes of this chapter, the land use hearing examiner may attach such conditions to the granting of variances as it deems necessary to further the purposes of this chapter.

(6) The floodplain administrator shall maintain the records of all appeal actions and report any variances to the Federal Insurance Administration upon request. (Ord. 1598 § 26, 2017; Ord. 1521 §§ 1, 2, 2012; Ord. 844 § 3.4-1, 1989)

15.12.170 Condition of variances.

(1) Generally, the only condition under which a variance from the elevation standard may be issued if for the 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 WMC 15.12.160(4)(A) through (K) have been fully considered.

(2) Variances may be issued for the reconstruction, rehabilitation or restoration of structures listed on the National Register of Historic Places or the State Inventory of Historical Places, without regard to the procedures set forth in this section.

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

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

(5) Variances shall only be issued upon:

(A) A showing of good and sufficient cause;

(B) 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 as identified in WMC 15.12.160(4) or conflict with existing local laws or ordinances.

(6) 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.

(7) 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 (1) of this section, and otherwise complies with WMC 15.12.190 and 15.12.200.

(8) Any applicant to whom a variance is granted shall be given written notice that the structure will be permitted to be built with a lowest floor elevation below the base flood elevation and that the cost of flood insurance will be commensurate with the increased risk resulting from the reduced lowest floor elevation. (Ord. 844 § 3.4-2, 1989)

15.12.180 Flood hazard reduction provisions.

In all areas of special flood hazards, the standards set out in WMC 15.12.190 through 15.12.230 are required. (Ord. 844 § 4.1, 1989)

15.12.190 Anchoring.

(1) All new construction and substantial improvements shall be anchored to prevent flotation, collapse or lateral movement of the structure.

(2) All manufactured homes must likewise be anchored to prevent flotation, collapse or lateral movement, and 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. 844 § 4.1-1, 1989)

15.12.200 Construction materials and methods.

(1) All new construction and substantial improvements which are below the base flood elevation 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 the conditions of flooding. (Ord. 1598 § 18, 2017; Ord. 844 § 4.1-2, 1989)

15.12.210 Utilities.

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

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

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

(4) Water wells shall be located on high ground that is not in a floodway. (Ord. 1598 § 19, 2017; Ord. 844 § 4.1-3, 1989)

15.12.220 Subdivision proposals.

(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) 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 which contain at least 50 lots or five acres (whichever is less). (Ord. 844 § 4.1-4, 1989)

15.12.230 Review of building permits.

Where elevation data is not available either through the flood insurance study or from another authoritative source (WMC 15.12.120), 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 use of historical data, high water marks, photographs of past flooding, etc., where available. Failure to elevate at least two feet above grade in these zones may result in higher insurance rates. (Ord. 844 § 4.1-5, 1989)

15.12.240 Specific standards.

In all areas of special flood hazards where base flood elevation data has been provided as set forth in WMC 15.12.030, or WMC 15.12.120, the provisions set forth in WMC 15.12.250 through 15.12.280 are required. (Ord. 844 § 4.2, 1989)

15.12.250 Residential construction.

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

(2) Fully enclosed areas below the lowest floor that are subject to flooding are prohibited; areas below the lowest floor 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:

(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. (Ord. 1598 § 20, 2017; Ord. 844 § 4.2-1, 1989)

15.12.260 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 the level of the base flood elevation; or, together with attendant utility and sanitary facilities, shall:

(1) 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;

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

(3) Be certified by a registered professional engineer or architect that the design and methods of construction are in accordance with accepted standards of practice for meeting provisions of this 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 WMC 15.12.110(2).

(4) Nonresidential structures that are elevated, not floodproofed, must meet the same standards for space below the lowest floor as described in WMC 15.12.250(2).

(5) 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). (Ord. 844 § 4.2-2, 1989)

15.12.270 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 floodwaters. Access routes elevated to or above the level of the base floodplain shall be provided to all critical facilities to the extent possible. (Ord. 844 § 4.2-3, 1989)

15.12.280 Manufactured homes.

All manufactured homes within the floodplain to be placed or substantially improved on sites shall be elevated on a permanent foundation designed in accordance with WMC 15.12.250, such that the lowest floor is elevated to one foot or more above the base flood elevation, and be securely anchored to an adequate foundation system to resist flotation, collapse and lateral movement. (Ord. 1598 § 21, 2017; Ord. 1441 § 6, 2008; Ord. 844 § 4.2-4, 1989)

15.12.290 Floodways.

Located within areas of special flood hazard established in WMC 15.12.030 are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of floodwaters that can carry debris, and increase 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 analysis 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 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, may be excluded from 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 these regulations. (Ord. 1441 § 7, 2008; Ord. 844 § 4.3, 1989)

15.12.300 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 the 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. (Ord. 844 § 4.4, 1989)

15.12.310 Standards for shallow flooding areas (AO zones).

Shallow flooding areas appear on the FIRM 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 and substantial improvements of residential structures within AO zones shall have the lowest floor (including basement) elevated above the highest grade adjacent to the building one foot or more above the depth number specified on the FIRM (at least two feet if no depth number is specified).

(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 floodproofed to or above that level and designed 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 WMC 15.12.260(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) Are on the site for fewer than 180 consecutive days; or

(B) Are 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 (1) and (3) of this section and the anchoring requirements for the manufactured home. (Ord. 1598 § 22, 2017; Ord. 1441 § 8, 2008; Ord. 844 § 4.5, 1989)

15.12.320 Coastal high hazard areas.

Located within areas of special flood hazard established in WMC 15.12.030 are coastal high hazard areas, designated as Zones V1 – V30, VE and/or V. These areas have special flood hazards associated with high velocity waters from surges and, therefore, in addition to meeting all provisions of this chapter, the following provisions shall also apply:

(1) Due to the dynamic nature of coastal high hazard areas located along the Pacific Ocean, in areas with designated velocity zones (V zones) from Cape Disappointment to Cape Flattery, the following standards shall apply:

(A) Prohibit new or substantially improved construction in designated V zones; exceptions are for needed water-dependent structures or structures that facilitate public recreational access to the shore. Structures which require siting in the V zone should be sited landward of the primary dune if an active dune system is associated with the V zone.

(B) Prohibit any alteration of dunes in the above-designated V zones which could increase the potential flood damage; this restriction includes prohibiting any modification or alteration or disturbance of vegetative cover associated with dunes located in designated V zones.

(2) All new allowable construction and substantial improvements in zones V1 – V30 and VE, and zone V if base flood elevation data is available, 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 the 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 and water loads acting simultaneously on all building components. Water loading values used shall be those associated with the base flood. Wind loading values used shall be those required by applicable state or local building standards.

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 subsection (2)(A) and (B) of this section.

(3) 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 zones V1 – V30 and VE, and whether or not such structures contain a basement. The floodplain administrator shall maintain a record of all such information.

(4) All new construction within zones V1 – V30, VE, and V shall be located landward of the reach of mean high tide.

(5) Provide that all new construction and substantial improvements have the space below the lowest floor either free of obstruction or constructed with nonsupporting 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 purpose 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 designs proposed meet 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).

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

(7) Prohibit the use of fill for structural support of buildings.

(8) Prohibit manmade alteration of sand dunes which would increase potential flood damage.

(9) All manufactured homes to be placed or substantially improved within Zones V1 – V30, V and 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 a result of a flood;

shall meet the standards of subsections (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 Zones V1 – V30, V, and VE on the community’s FIRM, shall meet the requirements of WMC 15.12.190(2).

(10) Recreational vehicles placed on sites within Zones V1 – V30, V, and VE on the community’s FIRM either:

(A) Are on site for fewer than 180 consecutive days; or

(B) Are fully licensed and ready for 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 WMC 15.12.070 and subsections (1) through (8) of this section. (Ord. 1598 §§ 23, 26, 2017; Ord. 1441 § 9, 2008; Ord. 844 § 4.6, 1989)

15.12.325 Recreational vehicles in A, AE, AO, V, and VE zones.

Recreational vehicles placed on sites are required to either:

(1) Be on site for fewer than 180 days; (or)

(2) Be fully licensed and ready for highway use, on wheels or jacking system, attached to the site only by quick-disconnect utilities and security devices, and have no permanently attached additions; or

(3) Meet the requirements and the elevation and anchoring requirements for manufactured homes. (Ord. 1598 § 24, 2017; Ord. 1441 § 10, 2008)

15.12.330 AE and A1-30 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 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. 1441 § 11, 2008)

15.12.335 Construction of below-grade crawlspaces for buildings located in special flood hazard areas.

The interior grade of a crawlspace below the BFE must not be more than two feet below the lowest adjacent grade (LAG).

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 four feet at any point. The height limitation is the maximum allowable unsupported wall height according to the engineering analysis and building code requirements for the flood hazard areas. This limitation will also prevent these crawlspaces from being converted into habitable spaces.

There must be an adequate drainage system that removes floodwaters from the interior area of the crawlspace. The enclosed area should be drained within a reasonable time after a flood event. The type of drainage system will vary because of the site gradient and other drainage characteristics, such as soil types. Possible options include natural drainage through porous, well-drained soils and drainage systems such as perforated pipes, drainage tiles, or gravel or crushed stone drainage by gravity or mechanical means.

The velocity of floodwaters at the site should not exceed five feet per second for any crawlspace. For velocities in excess of five feet per second, other foundation types should be used.

Below-grade crawlspace construction in accordance with the requirements listed above will not be considered basements. (Ord. 1598 § 25, 2017; Ord. 1441 § 12, 2008)

15.12.340 Violation and penalty.

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 invoked in the case. Nothing herein contained shall prevent the city from taking such other lawful action as is necessary to prevent or remedy any violation. (Ord. 1441 § 13, 2008)