Chapter 9.02 CONSTRUCTION IN FLOOD HAZARD AREAS

(1) “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 waterbody.

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

(3) “Area of shallow flooding” means a designated Zone AO, AH, AR/AO or AR/AH (or VO) on a community’s flood insurance rate map (FIRM) with a one percent or greater annual chance of flooding to an average depth of one to three feet where a clearly defined channel does not exist, where the path of flooding is unpredictable, and where velocity flow may be evident. Such flooding is characterized by ponding or sheet flow. Also referred to as the sheet flow area.

(4) “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. It is shown on the flood insurance rate map (FIRM) as Zone A, AO, AH, A1 – 30, AE, A99, AR (V, VO, V1 – 30, VE). “Special flood hazard area” is synonymous in meaning with the phrase “area of special flood hazard.”

(5) “Base flood” means the flood having a one percent chance of being equaled or exceeded in any given year.

(6) “Base flood elevation” (BFE) means the elevation to which floodwater is anticipated to rise during the base flood.

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

(8) “Breakaway walls” 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.

(9) “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. The area is designated on the FIRM as Zone V1 – 30, VE or V.

(10) “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.

(11) “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.

(12) “Flood” or “flooding” means:

(a) A general and temporary condition of partial or complete inundation of normally dry land areas from:

(i) The overflow of inland or tidal waters.

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

(iii) Mudslides (i.e., mudflows) which are proximately caused by flooding as defined in subsection (12)(b) of this section 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.

(b) 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 (12)(a) of this section.

(13) “Flood elevation study” means an 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 a flood insurance study (FIS).

(14) “Flood insurance rate map (FIRM)” means the official map of a community, on which the Federal Insurance Administrator has delineated both the special hazard areas and the risk premium zones applicable to the community. A FIRM that has been made available digitally is called a digital flood insurance rate map (DFIRM).

(15) “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.

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

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

(18) “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 floodwater below the base flood elevation.

(19) “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 of more than a designated height. Also referred to as “regulatory floodway.”

(20) “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.

(21) “Habitable floor” means any floor usable for living purposes, which includes working, sleeping, eating, cooking or recreation or a combination thereof. A floor used only for storage purposes is not a “habitable floor.”

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

(23) “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) By 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.

(24) “Local administrator” means the city manager of the city or his designee.

(25) “Lowest floor” means the lowest floor of the lowest enclosed area (including basement). An unfinished or flood-resistant enclosure, usable solely for the 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 NPMC 9.02.180(1).

(26) “Manufactured home” means any 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” does not include a “recreational vehicle.”

(27) “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.

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

(29) “New construction,” for the purposes of determining insurance rates, means 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 structure

(30) “Reasonably safe from flooding” means development that is designed and built to be safe from flooding based on consideration of current flood elevation studies, historical data, high water marks and other reliable data known to the community. In unnumbered A zones where flood elevation information is not available and cannot be obtained by practicable means, “reasonably safe from flooding” means that the lowest floor is at least two feet above the highest adjacent grade.

(31) “Recreational vehicle” means a vehicle:

(a) Built on a single chassis;

(b) Four hundred square feet or less when measured at the largest horizontal projection;

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

(32) “Start of construction” includes substantial improvement, and means the date the building permit was issued; provided, that the actual start of construction, repair, reconstruction, placement or other improvement was within 180 days from 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 the 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. For a substantial improvement, the “actual start of construction” means the first alteration of any wall, ceiling, floor, or other structural part of a building, whether or not that alteration affects the external dimensions of the building 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.

(33) “Structure,” for floodplain management purposes, means a walled and roofed building, including a gas or liquid storage tank that is principally above ground, as well as a manufactured home.

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

(35) “Substantial improvement” means any reconstruction, rehabilitation, addition, or other 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:

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

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

(36) “Variance” means a grant of relief from the requirements of this chapter that permits construction in a manner that would otherwise be prohibited by this chapter. (Ord. 1017 § 2 (Exh. A), 2020; Ord. 739 § 1, 2004; Ord. 507 § 1, 1989).

Article II. General Provisions

9.02.020 Applicability.

This chapter shall apply to all special flood hazard areas within the boundaries of the city of Normandy Park. (Ord. 1017 § 2 (Exh. A), 2020).

9.02.030 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 (FIS) for King County, Washington and Incorporated Areas,” August 19, 2020, and any revisions thereto, with accompanying flood insurance rate maps (FIRMs) dated August 19, 2020, and any revisions thereto, are hereby adopted by reference and declared to be part of this chapter. This FIS and the FIRM are on file at City Hall, 801 SW 174th Street, Normandy Park, WA 98166.

The best available information for flood hazard area identification as outlined in NPMC 9.02.110 shall be the basis for regulation until a new FIRM is issued that incorporates data utilized under NPMC 9.02.110. (Ord. 1017 § 2 (Exh. A), 2020; Ord. 739 § 2, 2004; Ord. 594 § 1, 1994; Ord. 507 § 2(a), 1989. Formerly 9.02.020).

9.02.040 Compliance – Penalties.

No structure or land shall hereafter be developed, constructed, located, extended, converted or altered without full compliance with the terms of this title and other applicable regulations. Any structure or land hereafter constructed, located, extended, converted or altered in violation of this chapter may be deemed a public nuisance. Violation of the provisions of this chapter by failure to comply with any of these 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 the requirements set forth herein shall, upon conviction, be fined not more than $1,000 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 from taking such other lawful action as is necessary to prevent or remedy such violation. (Ord. 1017 § 2 (Exh. A), 2020; Ord. 507 § 2(b), 1989. Formerly 9.02.030).

9.02.050 Abrogation and greater restrictions.

This chapter is not intended to repeal, abrogate or impair any existing easement, 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. 1017 § 2 (Exh. A), 2020; Ord. 507 § 2(c), 1989. Formerly 9.02.040).

9.02.060 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 to the city under state statutes. (Ord. 1017 § 2 (Exh. A), 2020; Ord. 507 § 2(d), 1989. Formerly 9.02.050).

9.02.070 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 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 any legal 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 thereunder. (Ord. 1017 § 2 (Exh. A), 2020; Ord. 507 § 2(e), 1989. Formerly 9.02.060).

Article III. Administration

9.02.080 Development permit required.

A development permit shall be obtained before construction or development begins within any area of flood hazard established in NPMC 9.02.030. The permit shall be for all structures including manufactured homes, as defined in NPMC 9.02.010, and for all other development including fill and other activities, also as defined in NPMC 9.02.010. Application for a development permit shall be made on forms furnished by the local administrator and shall 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, on-site storage of materials, drainage facilities; and the location of the foregoing. Specifically, the following information shall be furnished by the applicant:

(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 NPMC 9.02.180(2);

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

(5) Where a structure is proposed in a V, V1 – 30, or VE zone, a V-zone design certificate;

(6) Where development is proposed in a floodway, an engineering analysis indicating no rise of the base flood elevation; and

(7) Any other such information that may be reasonably required by the floodplain administrator in order to review the application. (Ord. 1017 § 2 (Exh. A), 2020; Ord. 507 § 3(a), 1989. Formerly 9.02.070).

9.02.090 Changes to special flood hazard area.

(1) If a project will alter the BFE or boundaries of the SFHA, then the project proponent shall provide the community with engineering documentation and analysis regarding the proposed change. If the change to the BFE or boundaries of the SFHA would normally require a letter of map change, then the project proponent shall initiate, and receive approval of, a conditional letter of map revision (CLOMR) prior to approval of the development permit. The project shall be constructed in a manner consistent with the approved CLOMR.

(2) If a CLOMR application is made, then the project proponent shall also supply the full CLOMR documentation package to the floodplain administrator to be attached to the floodplain development permit, including all required property owner notifications. (Ord. 1017 § 2 (Exh. A), 2020).

9.02.100 Designation of the floodplain administrator – Duties and responsibilities.

(1) The city manager is hereby appointed to administer, implement, and enforce this chapter by granting or denying development permits in accordance with its provisions. The floodplain administrator may delegate authority to implement these provisions.

(2) Duties of the local administrator shall include, but not be limited to:

(a) Permit Review.

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

(ii) 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.

(iii) 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 NPMC 9.02.190(1) are met.

(iv) Review all development permits to determine that all other required state and federal permits have been obtained.

(v) Notify FEMA when annexations occur in the special flood hazard area.

(vi) Ensure the site is reasonably safe from flooding. (Ord. 1017 § 2 (Exh. A), 2020; Ord. 507 § 3(b), 1989. Formerly 9.02.080).

9.02.110 Use of other base flood data.

When base flood elevation data has not been provided in accordance with NPMC 9.02.030, the local 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 NPMC 9.02.180(1) and (2) and 9.02.190. (Ord. 1017 § 2 (Exh. A), 2020; Ord. 739 § 3, 2004; Ord. 507 § 3(c), 1989. Formerly 9.02.090).

9.02.120 Information to be obtained and maintained.

(1) Where base flood elevation data is provided through the FIS, FIRM, or required as in NPMC 9.02.110, obtain and maintain a record of 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) Obtain and maintain documentation of the elevation of the bottom of the lowest horizontal structural member in V or VE zones.

(3) For all new or substantially improved floodproofed nonresidential structures where base flood elevation data is provided through the FIS, FIRM, or as required in NPMC 9.02.110:

(a) Obtain and maintain a record of the elevation (in relation to mean sea level) to which the structure was floodproofed.

(b) Maintain the floodproofing certifications required in NPMC 9.02.080(3).

(4) Certification required by NPMC 9.02.080(3).

(5) Records of all variance actions, including justification for their issuance.

(6) Improvement and damage calculations.

(7) Maintain for public inspection all records pertaining to the provisions of this chapter. (Ord. 1017 § 2 (Exh. A), 2020; Ord. 739 § 4, 2004; Ord. 507 § 3(d), 1989. Formerly 9.02.100).

9.02.130 Alteration of watercourses.

(1) Notify adjacent communities and the State Department of Ecology (DOE) 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. 1017 § 2 (Exh. A), 2020; Ord. 507 § 3(e), 1989. Formerly 9.02.110).

9.02.140 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 Article IV of this chapter. (Ord. 1017 § 2 (Exh. A), 2020; Ord. 507 § 3(f), 1989. Formerly 9.02.120).

Article IV. Appeals and Variances

9.02.150 Appeals and variances.

(1) Any person aggrieved by any permit decision of the local administrator may appeal the decision to the hearing examiner as provided in Chapter 18.150 NPMC.

(2) Requests for variances from the requirements of this chapter or any administrative appeal timely filed shall be made to the hearing examiner as provided in Chapter 18.150 NPMC.

(3) When considering an application for a variance to any provisions of this chapter, the hearing examiner shall, in addition to the variance criteria set forth in NPMC 18.20.030, consider all technical evaluations, all relevant factors and standards specified in other sections of this chapter, and:

(a) The danger that materials may be swept into 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 alternate 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 height, velocity, duration, rate of rise, and sediment transport of the floodwaters and the effects of wave actions, if applicable, expected at the site; and

(k) The costs of providing government 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. (Ord. 1017 § 2 (Exh. A), 2020; Ord. 924 § 2(B), 2015; Ord. 833 § 3, 2009; Ord. 507 § 4(a), (b), 1989. Formerly 9.02.130).

9.02.160 Conditions for variances.

(1) Generally, the only condition under which a variance from the elevation standard may be granted shall be for new construction and substantial improvements to be erected on a lot of one-half acre or less in size continuous to and surrounded by lots with existing structures constructed below base flood level; provided, that the variance criteria listed above have been fully considered.

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

(3) Variances shall only be granted upon demonstration of compliance with Chapter 18.20 NPMC and the following:

(a) Upon 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;

(b) 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;

(d) Upon a showing that the use cannot perform its intended purpose unless it is located or carried out in close proximity to water. This includes only facilities defined as a “functionally dependent use” in NPMC 9.02.010.

(4) Variances as interpreted in the National Flood Insurance Program are based on the general zoning law principle that such variances pertain to a physical piece of property; such variances being not personal in nature and do not pertain to a structure, inhabitants thereof, or economic or financial circumstances.

(5) Variances may be granted 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 a load damage potential, complies with all other variance criteria except subsection (3)(b) of this section, and otherwise complies with the general standards of this chapter.

(6) 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. 1017 § 2 (Exh. A), 2020; Ord. 507 § 4(c), 1989. Formerly 9.02.140).

Article V. Provisions for Flood Hazard Protection

9.02.170 General standards and requirements.

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. 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 Material 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, substantial improvements, and placement of manufactured homes 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 floodwaters into the system;

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

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

(d) Water wells shall be located on high ground that is not in the floodway.

(4) Subdivision Proposals and New Development.

(a) All subdivisions, as well as new development, shall:

(i) Be consistent with the need to minimize flood damage;

(ii) Have public utilities and facilities such as sewer, gas, electrical, and water systems located and constructed to minimize flood damage;

(iii) Have adequate drainage provided to reduce exposure to flood damage; and

(iv) Base flood elevation data shall be provided for subdivision proposals and other proposed development that requires a development permit.

(5) General Requirements for Other Development. All development, including manmade changes to improved or unimproved real estate for which specific provisions are not specified in this chapter or the state building codes with adopted amendments and any city of Normandy Park amendments, shall:

(a) Be located and constructed to minimize flood damage;

(b) Meet the encroachment limitations of this chapter if located in a regulatory floodway;

(c) Be anchored to prevent flotation, collapse, or lateral movement resulting from hydrostatic loads, including the effects of buoyancy, during conditions of the design flood;

(d) Be constructed of flood damage-resistant materials;

(e) Meet the flood opening requirements of NPMC 9.02.180(1)(e); and

(f) Have mechanical, plumbing, and electrical systems above the design flood elevation or meet the requirements of ASCE 24, except that minimum electric service required to address life safety and electric code requirements is permitted below the design flood elevation provided it conforms to the provisions of the electrical part of building code for wet locations.

(6) Review of Building Permits. Where elevation data is not available either through the flood insurance study or from another authoritative source, applications for building permits shall be reviewed to assure that proposed construction will be reasonably safe from flooding. The test of reasonableness is a 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. 1017 § 2 (Exh. A), 2020; Ord. 739 § 5, 2004; Ord. 507 § 5(a), 1989. Formerly 9.02.150).

9.02.180 Specific standards.

In all areas of special flood hazards where base flood elevation data has been provided as set forth in NPMC 9.02.030 or 9.02.110, the following provisions are required:

(1) Residential Construction.

(a) In AE and A1 – 30 zones or other A zoned areas where the BFE has been determined or can be reasonably obtained, new construction and substantial improvement of any residential structure shall have the lowest floor, including basement, elevated one foot or more above the BFE. Mechanical equipment and utilities shall be waterproof or elevated at least one foot above the BFE.

(b) New construction and substantial improvement of any residential structure in an AO zone shall meet the requirements in Appendix A.

(c) New construction and substantial improvement of any residential structure in an unnumbered A zone for which a BFE is not available and cannot be reasonably obtained shall be reasonably safe from flooding, but in all cases the lowest floor shall be at least two feet above the highest adjacent grade.

(d) New construction and substantial improvement of any residential structure in a V, V1 – 30, or VE zone shall meet the requirements in Appendix B.

(e) Fully enclosed areas below the lowest floor that are subject to flooding are prohibited, or shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwaters. Designs must meet or exceed the following minimum criteria:

(i) Have a minimum of two openings with a total net area of not less than one square inch for every square foot of enclosed area subject to flooding.

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

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

(iv) A garage attached to a residential structure, constructed with the garage floor slab below the BFE, must be designed to allow for the automatic entry and exit of floodwaters.

(v) Alternatively, a registered engineer or architect may design and certify engineered openings.

(2) Nonresidential Construction. New construction and substantial improvement of any commercial, industrial or other nonresidential structure shall meet the requirements of subsection (2)(a) or (b) of this section.

(a) New construction and substantial improvement of any commercial, industrial or other nonresidential structure shall meet all of the following requirements:

(i) In AE and A1 – 30 zones or other A zoned areas where the BFE has been determined or can be reasonably obtained:

New construction and substantial improvement of any commercial, industrial, or other nonresidential structure shall have the lowest floor, including basement, elevated one foot or more above the BFE, or elevated as required by ASCE 24, whichever is greater. Mechanical equipment and utilities shall be waterproofed or elevated least one foot above the BFE, or as required by ASCE 24, whichever is greater.

(ii) If located in an AO zone, the structure shall meet the requirements in Appendix A.

(iii) If located in an unnumbered A zone for which a BFE is not available and cannot be reasonably obtained, the structure shall be reasonably safe from flooding, but in all cases the lowest floor shall be at least two feet above the highest adjacent grade.

(iv) If located in a V, V1 – 30, or VE zone, the structure shall meet the requirements in Appendix B.

(v) Fully enclosed areas below the lowest floor that are subject to flooding are prohibited, or shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwaters. Designs for meeting this requirement must either be certified by a registered professional engineer or architect or must meet or exceed the following minimum criteria:

(A) Have a minimum of two openings with a total net area of not less than one square inch for every square foot of enclosed area subject to flooding.

(B) The bottom of all openings shall be no higher than one foot above grade.

(C) Openings may be equipped with screens, louvers, valves, or other coverings or devices; provided, that they permit the automatic entry and exit of floodwater.

(D) A garage attached to a residential structure, constructed with the garage floor slab below the BFE, must be designed to allow for the automatic entry and exit of floodwaters.

(E) Alternatively, a registered engineer or architect may design and certify engineered openings.

(b) If the requirements of subsection (2)(a) of this section are not met, then new construction and substantial improvement of any commercial, industrial or other nonresidential structure shall meet all of the following requirements:

(i) Be dry floodproofed so that below one foot or more above the base flood level the structure is watertight with walls substantially impermeable to the passage of water or dry floodproofed to the elevation required by ASCE 24, whichever is greater;

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

(iii) 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 floodplain administrator as set forth in NPMC 9.02.080(3).

(iv) Nonresidential structures that are elevated, not floodproofed, must meet the same standards for space below the lowest floor as described in subsection (4) of this section.

(c) Applicants who are 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 the base flood level will be rated as one foot below). Floodproofing the building an additional foot will reduce insurance premiums.

(3) Manufactured Homes. All manufactured homes to be placed or substantially improved within Zones A1 – 30, AH, and AE on the community’s FIRM shall be elevated on a permanent foundation such that the lowest floor of the manufactured home is to or above the base flood elevation; and be securely anchored to an adequately anchored foundation system in accordance with the provisions of NPMC 9.02.170(1).

(4) Enclosed Area Below the Lowest Floor. If buildings or manufactured homes are constructed or substantially improved with fully enclosed areas below the lowest floor, the areas shall be used solely for parking of vehicles, building access, or storage.

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

(6) Accessory Structures (Detached Garages and Small Storage Structures). Accessory structures shall meet the standards provided below, for A zones (A, AE, A1 – 30, AH, AO):

(a) Accessory structures used solely for parking of vehicles or limited storage may be constructed such that the floor is below the BFE, provided the structure is designed and constructed in accordance with the following requirements:

(i) Use of the accessory structure must be limited to parking of vehicles or limited storage;

(ii) The portions of the accessory structure located below the BFE must be built using flood-resistant materials;

(iii) The accessory structure must be adequately anchored to prevent flotation, collapse, and lateral movement;

(iv) Any machinery or equipment servicing the accessory structure must be elevated or floodproofed to or above the BFE;

(v) The accessory structure must comply with floodway encroachment provisions in NPMC 9.02.190(1);

(vi) The accessory structure must be designed to allow for the automatic entry and exit of floodwaters in accordance with the applicable standards in subsections (1) and (2) of this section;

(vii) The structure shall have low damage potential;

(viii) If the structure is converted to another use, it must be brought into full compliance with the standards governing such use; and

(ix) The structure shall not be used for human habitation.

(b) Detached garages, storage structures, and other appurtenant structures not meeting the above standards must be constructed in accordance with all applicable standards in subsections (1) and (2) of this section.

(c) Upon completion of the structure, certification that the requirements of this section have been satisfied shall be provided to the floodplain administrator for verification.

(7) Vehicles (44 CFR 60.3(c)(14)).

(a) Recreational vehicles placed on sites are required to either:

(i) Be on the site for fewer than 180 consecutive days, or

(ii) Be fully licensed and ready for highway use, on wheels or jacking system, attached to the site only by quick disconnect type utilities and security devices, and have no permanently attached additions; or meet the requirements of subsection (6) of this section. (Ord. 1017 § 2 (Exh. A), 2020; Ord. 739 § 6, 2004; Ord. 507 § 5(b), 1989. Formerly 9.02.160).

9.02.190 Floodways.

Located within areas of special flood hazard established in NPMC 9.02.030 are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of floodwaters that carry debris, potential projectiles, and erosion potential, the following provisions apply:

(1) Prohibit encroachments, including fill, new constructions, 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 encroachment 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 that 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 and local health, sanitary, or safety code specifications that have been identified by the local code enforcement official and that are the minimum necessary to assure safe living conditions, or to structures identified as historic places, may be excluded in the 50 percent.

(3) If subsection (1) of this section is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of NPMC 9.02.170 through 9.02.180. (Ord. 1017 § 2 (Exh. A), 2020; Ord. 739 § 7, 2004; Ord. 507 § 5(c), 1989. Formerly 9.02.170).

9.02.200 Wetlands management.

To the maximum extent possible, each development subject to this chapter shall 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 shall be implemented for such development:

(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 ability of the wetland 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) may be used in conjunction with the area’s FIRM to prepare an overlay zone indicating critical wetland areas deserving special attention. (Ord. 1017 § 2 (Exh. A), 2020; Ord. 507 § 5(d), 1989. Formerly 9.02.180).

9.02.210 Coastal high hazard area.

Located within areas of special flood hazard, established in NPMC 9.02.030, 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 in Normandy Park Ordinance No. 1017, the following provisions shall also apply:

(1) All new allowable construction and substantial improvement in Zones V1 – V30 and VE (V if base flood elevation data is available) on the community’s FIRM shall be elevated on pilings and columns so that:

(a) Elevations.

(i) Residential Buildings. The bottom of the lowest horizontal structural member of the lowest floor (excluding the piling or columns) is elevated to or above the base flood level; and

(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.

(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 (1)(a) and (b) 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 Zones V1 – 30 and VE, and V on the community’s FIRM and whether or not such structures contain a basement. The local floodplain administrator shall maintain a record of all such information.

(3) All new construction within Zones V1 – 30, VE, and V 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 Zones V1 – 30, VE, and V on the community’s FIRM 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 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 that 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 a 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).

(5) 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.

(6) Prohibit the use of fill for structural support of buildings within Zones V1 – 30, VE, and V on the community’s FIRM.

(7) Prohibit manmade alteration of sand dunes within Zones V1 – 30, VE, and V on the community’s FIRM.

(8) All manufactured homes to be placed or substantially improved within Zones V1 – 30, 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;

(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 (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 – 30, V, and VE on the FIRM shall meet the requirements of NPMC 9.02.170(3).

(9) 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 (1) and (3) of this section and the anchoring requirements for manufactured homes in NPMC 9.02.170(1)(b). (Ord. 1017 § 2 (Exh. A), 2020; Ord. 739 § 8, 2004; Ord. 507 § 5(e), 1989. Formerly 9.02.190).

9.02.220 Encroachment.

The cumulative effect of any proposed development, when combined with all other existing and anticipated development, shall not increase the water surface elevation of the base flood more than one foot at any point. (Ord. 1017 § 2 (Exh. A), 2020; Ord. 507 § 5(f), 1989. Formerly 9.02.200).