Chapter 17.20 FLOOD DAMAGE PREVENTION

The Legislature of the state of Washington has delegated the responsibility to local governmental units to adopt regulations designed to promote the public health, safety, and general welfare of its citizenry. (Ord. 835 § 1.1, 1989).

17.20.020 Findings of fact.

(1) The flood hazard areas of the city of Oak Harbor are subject to periodic inundation which results in loss of life and property, health, and safety hazards, disruption of commerce and governmental services, extraordinary public expenditures for flood protection and relief, and impairment of the tax base, all of which adversely affect the public health, safety, and general welfare;

(2) These flood losses are caused by the cumulative effect of obstructions in areas of special flood hazards which increase flood heights and velocities, and when inadequately anchored, damage uses in other areas. Uses that are inadequately floodproofed, elevated, or otherwise protected from flood damage also contribute to the flood loss. (Ord. 835 § 1.2, 1989).

17.20.030 Statement of purpose.

It is the purpose of this chapter to promote the public health, safety, and general welfare and to minimize public and private losses due to flood conditions in specific areas by provisions designed:

(1) To protect human life and health;

(2) To minimize expenditure of public money and costly flood control projects;

(3) To minimize the need for rescue and relief efforts associated with flooding and generally undertaken at the expense of the general public;

(4) To minimize prolonged business interruptions;

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

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

(7) To ensure that potential buyers are notified that property is in an area of special flood hazard;

(8) To ensure that those who occupy the areas of special flood hazard assume responsibility for their actions;

(9) To maintain the quality of water in rivers, streams, lakes, estuaries, and marine areas and their floodplains so as to protect public water supplies, areas of the public trust, and wildlife habitat protected by the Endangered Species Act;

(10) To retain the natural channel, shoreline, and floodplain creation processes and other natural floodplain functions that protect, create, and maintain habitat for threatened and endangered species;

(11) To prevent or minimize loss of hydraulic, geomorphic, and ecological functions of floodplains and stream channels; and

(12) To qualify the city of Oak Harbor for participation in the National Flood Insurance Program, thereby giving citizens and businesses the opportunity to purchase flood insurance. (Ord. 1794 § 2, 2017; Ord. 835 § 1.3, 1989).

17.20.040 Methods of reducing flood losses.

In order to accomplish its purposes, this chapter includes methods and provisions for:

(1) Restricting or prohibiting uses which are dangerous to health, safety, and property due to water or erosion hazards, or which result in damaging increases in erosion or in flood heights or velocities;

(2) Requiring that uses vulnerable to floods, including facilities which serve such uses, be protected against flood damage at the time of initial construction;

(3) Controlling the alteration of natural floodplains, stream channels, and natural protective barriers, which help accommodate or channel floodwaters;

(4) Controlling filling, grading, and other development which may increase flood damage; and

(5) Preventing or regulating the construction of flood barriers which will unnaturally divert floodwaters or may increase flood hazards in other areas. (Ord. 835 § 1.4, 1989).

Article II. Definitions

17.20.050 Definitions.

Unless specifically defined below, words or 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.

(1) “Appeal” means a request for a review of the building official’s interpretation of any provision of this chapter or a request for a variance.

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

(3) “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.

(4) “Base flood” means the flood having a one percent chance of being equaled or exceeded in any given year (also referred to as the “100-year flood”) as designated on Flood Insurance Rate Maps by the letters A or V.

(5) “Basement” means any area of a building having its floor subgrade (below ground level) on all sides. The floor does not have to be finished; it can be a dirt floor.

(6) “Breakaway wall” means a wall that is not part of the structural support of the building and that 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.

(7) “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.

(8) “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.

(9) “Development” means any manmade change to improved or unimproved real estate in the regulatory floodplain, including but not limited to buildings or other structures, mining, dredging, filling, grading, paving, excavation, drilling operations or storage of equipment or materials, subdivision of land, removal of five percent of the native vegetation on the property, or alteration of natural site characteristics.

(10) “Flood” or “flooding” means a general and temporary condition or 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 of surface waters from any source.

(11) “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.

(12) “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.

(13) “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.

(14) “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 OHMC 17.20.190(1)(b).

(15) “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.

(16) “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.

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

(18) “Protected area” means the lands that lie within the boundaries of the floodway, riparian habitat zone, or the channel migration area.

(19) “Recreational vehicle” means a vehicle which is:

(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.

(20) “Regulatory floodplain” means the area of the special flood hazard area in addition to the protected area.

(21) “Start of construction” includes substantial improvement, and means the date the building permit was issued, provided the actual start of construction, repair, reconstruction, placement or other improvement was within 180 days of the permit date. The “actual start” means either the first placement of permanent construction of a structure on a site, such as the pouring of slab or footings, the installation of piles, the construction of columns, or any work beyond the stage of excavation, or the placement of a manufactured home on a foundation. Permanent construction does not include land preparation, such as clearing, grading and filling; nor does it include the installation of streets and/or walkways; nor does it include excavation for a basement, footings, piers, or 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.

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

(23) “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.

(24) “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 does not, however, include either: (a) any project for improvement of a structure to correct precited existing violations of state or local health, sanitary, or safety code specifications which have been identified by the 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.

(25) “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.

(26) “Water-dependent” means a structure for commerce or industry which cannot exist in any other location and is dependent on the water by reason of the intrinsic nature of its operations. (Ord. 1794 § 3, 2017; Ord. 1704 § 1, 2014; Ord. 1472 § 1, 2006; Ord. 835 § 2, 1989).

Article III. General Provisions

17.20.060 Lands to which this chapter applies.

This chapter shall apply to the regulatory floodplain, which is comprised of the special flood hazard area and protected area within the jurisdiction of the city of Oak Harbor. (Ord. 1794 § 4, 2017; Ord. 835 § 3.1, 1989).

17.20.070 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 of Island County and Incorporated Areas for the City of Oak Harbor,” dated March 7, 2017, and any revisions thereto, with an accompanying Flood Insurance Rate Map (FIRM) dated March 7, 2017, and any revisions thereto, are adopted by reference and declared to be a part of this chapter. The Flood Insurance Study and the FIRM are on file in the office of the floodplain administrator at Oak Harbor City Hall, 865 SE Barrington Dr., Oak Harbor, Washington 98277. The best available information for flood hazard area identification as outlined in OHMC 17.20.150(2) shall be the basis for regulation until a new FIRM is issued that incorporated data utilized under OHMC 17.20.150(2). (Ord. 1799 § 1, 2017; Ord. 1794 § 5, 2017; Ord. 1704 § 2, 2014; Ord. 1472 § 1, 2006; Ord. 1016 § 1, 1995; Ord. 835 § 3.2, 1989).

17.20.080 Penalties for noncompliance.

No structure or land shall hereafter be constructed, located, extended, converted, or altered without full compliance with the terms of this chapter and other applicable regulations. Violation of the provisions of this chapter by failure to comply with any of its requirements (including violations of conditions and safeguards established in connection with conditions) shall constitute a misdemeanor. Any person who violates this chapter or fails to comply with any of its requirements shall upon conviction thereof be fined not more than $500.00 or imprisoned for not more than 90 days, or both, for each violation, and in addition shall pay all costs and expenses involved in the case. Nothing herein contained shall prevent the city of Oak Harbor from taking such other lawful action as is necessary to prevent or remedy any violation. (Ord. 835 § 3.3, 1989).

17.20.090 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 restriction shall prevail. (Ord. 835 § 3.4, 1989).

17.20.100 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. 835 § 3.5, 1989).

17.20.110 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 liability on the part of the city of Oak Harbor, 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. 835 § 3.6, 1989).

17.20.115 Severability.

Should any section, paragraph, sentence or word of this chapter or codes hereby adopted be declared for any reason to be invalid, it is the intent of the city council that it would have passed all other portions of this chapter and of the codes hereby adopted independent of the elimination herefrom of any such portions as may be declared invalid and accordingly such declaration of invalidity shall not affect the validity of this chapter as a whole nor any part hereof other than the part so declared to be invalid. (Ord. 1794 § 6, 2017).

Article IV. Administration

17.20.120 Development permit required.

A development permit shall be obtained before construction or development begins within any area of special flood hazard established in OHMC 17.20.070. The permit shall be for all structures including manufactured homes, as set forth in OHMC 17.20.050, and for all development including fill and other activities, also as set forth in OHMC 17.20.050. (Ord. 835 § 4.1.1, 1989).

17.20.130 Application for development permit.

(1) Application for a development permit shall be made on forms furnished by the building official and may include but not be limited to plans in duplicate drawn to scale showing the nature, location, dimensions, and elevations level (utilizing North American Vertical Datum – NAVD 88 protocol) of the area in question; existing or proposed structures, fill, storage of materials, draining facilities, and the location of the foregoing. Specifically, the following information is required:

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

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

(c) Certification by a registered professional engineer or architect that the floodproofing methods for any nonresidential structure meet the floodproofing criteria in OHMC 17.20.190(2);

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

(e) The nature, location, dimensions of any proposed improvements to the subject property;

(f) The names and locations of all lakes, water bodies, waterways and drainage facilities within 300 feet of the site;

(g) The elevations of the 10-, 50-, 100-, and 500-year floods;

(h) The boundaries of the regulatory floodplain, SFHA, floodway, riparian habitat zone, channel migration areas, and wetlands;

(i) The existing native vegetation and proposed revegetation areas; and

(j) Detailing of proposed floodproofing measures when applicable.

(2) The design and construction of structures shall comply with the most recent provisions of this title and the American Society of Civil Engineers (ASCE) and Structural Engineering Institute (SEI) Standard 14-14 for Flood Resistant Design and Construction. The design and construction of revetments shall comply with the Army Corps of Engineers respective standards.

(3) Proposed alternative methods for design and construction shall be in accordance with the intent of the provisions of this chapter and with this title. The alternative methods shall be reviewed and approved by building official prior to authorization for use.

(4) When approved by the building official, portions of buildings separated in accordance with adopted building code provisions for structural integrity and life safety may be considered as separate buildings for flood protection purposes; provided, that each building (from bottom of foundation to top of roof) shall maintain the minimum safety and flood protection standards as required for the highest level occupancy and hazard as defined for each separate structure.

(5) A registered professional engineer or architect shall be required to prepare all design and construction documents related to the issuance of a floodplain development permit, except therefrom elevation certificates which must be prepared by licensed surveyors.

(6) A registered professional engineer or architect shall be required to prepare all certificates of floodproofing and elevation certificates shall be prepared by a registered professional surveyor. The certificates shall be prepared on forms as prescribed by the floodplain administrator with elevation certificates prepared at the intervals as also prescribed.

(7) Biological opinions shall be prepared by persons possessing special knowledge of, and experience with, wildlife and botanical habitats as related to the Puget Sound environment. The biological opinion and assessment shall be submitted for review and approval prior to issuance of a floodplain development permit. Projects shall be designed and constructed to have no adverse effect on any listed species (e.g., Puget Sound Chinook salmon, Puget Sound steelhead, Hood Canal summer-run chum and Southern Resident killer whales, or other species that may become added as “listed”) or to their critical habitat.

(8) The floodplain development permit shall expire 180 days from the date of issuance if there has been no activity on the permit. Where the applicant documents a need for an extension beyond this period the floodplain administrator may authorize one or more extensions, not in excess of 90 days each. (Ord. 1794 § 7, 2017; Ord. 835 § 4.1.2, 1989).

17.20.140 Designation of the building official.

The building official is hereby appointed to administer and implement this chapter by granting or denying development permit applications in accordance with its provisions. (Ord. 835 § 4.2, 1989).

17.20.150 Duties of responsible official.

Duties of the building official shall include, but not be limited to:

(1) Permit Review.

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

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

(c) Review all development permits to determine if the proposed development is located in the floodway. If located in the floodway, assure that the provisions of OHMC 17.20.200 are met.

(2) Use of Other Base Flood Data. When base flood elevation data has not been provided in accordance with OHMC 17.20.070, the building official 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 OHMC 17.20.190 and 17.20.200.

(3) Information to be Obtained and Maintained.

(a) Where base flood elevation data is provided through the Flood Insurance Study or required as in subsection (2) of this section, 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.

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

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

(ii) Maintain the floodproofing certifications required in OHMC 17.20.130(3).

(4) Alteration of Watercourses.

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

(b) Require that maintenance is provided within the altered or relocated portion of said watercourse so that the flood carrying capacity is not diminished.

(5) Interpretation of FIRM Boundaries. Make interpretations where needed, as to exact locations 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 OHMC 17.20.160 and 17.20.170. (Ord. 835 § 4.3, 1989).

17.20.160 Variance procedure – Appeal board.

(1) The appeal board as established by the city of Oak Harbor shall hear and decide appeals and requests for variances from the requirements of this chapter.

(2) The appeal board shall hear and decide appeals when it is alleged there is an error in any requirement, decision, or determination made by the building official in the enforcement or administration of this chapter.

(3) Those aggrieved by the decision of the appeal board, or any taxpayer, may appeal such decision to the Island County superior court by writ of certiorari filed and served within 30 days of the decision.

(4) In passing upon such applications, the appeal board 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 facilities 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 appeal board may attach such conditions to the granting of variances as it deems necessary to further the purposes of this chapter.

(6) The building official shall maintain the records of all appeal actions and report any variances to the Federal Insurance Administration upon request. (Ord. 835 § 4.4.1, 1989).

17.20.170 Conditions for variances.

(1) Generally, the only condition under which a variance from the elevation standard may be issued is for new construction and substantial improvements to be erected on a lot of one-half acre or less in size contiguous to and surrounded by lots with existing structures constructed below the base flood level, providing items (a) through (k) in OHMC 17.20.160(4) have been fully considered. As the lot size increases the technical justification required for issuing the variance increases.

(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 Historic 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 failure to grant the variance would result in exceptional hardship to the applicant;

(c) 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 OHMC 17.20.160(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 OHMC 17.20.170(1), and otherwise complies with OHMC 17.20.180(1) and (2).

(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. 835 § 4.4.2, 1989).

17.20.175 Hearing examiner to function as appeals board.

All references to the term “board of appeal(s)” shall be deemed to mean the hearing examiner as per OHMC 18.40.180. Permits under this chapter shall be Type I review process as per OHMC 18.20.230. Appeals of decisions of applicable codes adopted under this chapter shall be to the hearing examiner. (Ord. 1794 § 8, 2017).

Article V. Provisions for Flood Hazard Reduction

17.20.180 General standards.

In all areas of special flood hazards, the following standards are required:

(1) Anchoring.

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

(b) All manufactured homes must likewise be anchored to prevent flotation, collapse or lateral movement, and shall be installed using methods and practices that minimize flood damage. Anchoring methods may include, but are not limited to, use of over-the-top or frame ties to ground anchors (for more detailed information, refer to guidebook, FEMA-85 “Manufactured Home Installation in Flood Hazard Areas”).

(2) Construction Materials and Methods.

(a) All new construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage.

(b) All new construction and substantial improvements shall be constructed using methods and practices that minimize flood damage.

(c) Electrical, heating, ventilation, plumbing, and air-conditioning equipment and other service facilities shall be designed and/or otherwise elevated or located so as to prevent water from entering or accumulating within the components during conditions of flooding.

(3) Utilities.

(a) All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of 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 them or contamination from them during flooding; and

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

(4) Subdivision Proposals.

(a) All subdivision proposals shall be consistent with the need to minimize flood damage;

(b) All subdivision proposals shall have public utilities and facilities such as sewer, gas, electrical, and water systems located and constructed to minimize flood damage;

(d) 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).

(5) Review of Building Permits. Where elevation data is not available either through the Flood Insurance Study or from another authoritative source (OHMC 17.20.150(2)), applications for building permits shall be reviewed to assure that proposed construction will be reasonably safe from flooding. The test of reasonableness is a local judgment and includes 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.

(6) Nondevelopment Activities. Activities that do not meet the definition of “development” are allowed in the regulatory floodplain without the need for a floodplain development permit provided all other federal, state and local floodplain development requirements are met. The following activities shall specifically be exempt from the requirement to obtain a floodplain development permit:

(a) Routine maintenance and landscaping that does not involve grading, excavation, filling or removal of more than five percent of the native vegetation on the property but that may involve the use and application of nonfertilized landscape toppings or mulch.

(b) Removal of noxious weeds and hazard trees.

(d) Normal maintenance of utilities, structures, and facilities, such as reroofing, painting, replacement of siding, and such other exterior work; provided, that such work does not qualify as a substantial improvement and where any native vegetation that is disturbed by the maintenance activity is fully restored.

(e) Normal maintenance of streets and roads including filling of potholes, crack-sealing, repaving, restriping, replacement of existing curbing, curb ramps, sidewalk or road barriers, and the installation of signs and traffic signals provided there is no expansion or elevation of gravel or paved areas.

(f) Normal maintenance of a levee or other flood control device or facility. Normal maintenance does not include repair from flood damage, expansion of the prism, expansion of the face or toe or addition for protection on the face or toe with rock or other such armor.

(g) Planting, harvesting, plowing, livestock management, and other normal farm or agricultural practices and activities. Not exempted is the clearing of land not previously cleared and the construction of agriculture buildings, structures, or other such facilities or the grading for preparation of said facilities.

(h) The lawful operation and maintenance of lawfully approved public and private diking and drainage systems which are designed to protect life and property.

(i) The replacement of existing exterior residential mechanical equipment (i.e., water heater, heat pump, compressor, and similar); provided, that the replacement equipment is satisfactorily anchored to a foundation and elevated to meet the standards in place when the building was constructed or substantially improved.

(7) Other Activities. The following activities are allowed in the regulatory floodplain without the need for a biological opinion or habitat impact assessment; provided, that all other requirements of this chapter are met, including obtaining a floodplain development permit; and further provided, that all other federal, state and local floodplain development requirements are met:

(a) Repairs or remodeling of an existing structure; provided, that the repairs or remodeling are not a substantial improvement or a repair of substantial damage.

(b) Expansion of an existing structure that is no greater than 10 percent beyond the legally permitted existing footprint effective as of January 1, 2017.

(c) Activities with the sole purpose of creating, restoring or enhancing natural functions associated with floodplains, streams, lakes, estuaries, marine areas, habitat, and riparian areas that meet federal, state and local standards, provided the activities do not include structures, grading, fill, impervious surfaces, or removal of more than five percent of the native vegetation on that portion of the property in the regulatory floodplain.

(d) Development of open space and recreational facilities, such as parks and trails that do not include structures, fill, impervious surfaces, or removal of more than five percent of the native vegetation on that portion of the property in the regulatory floodplain.

(e) Repair to existing on-site sanitary septic systems provided ground disturbance is the minimum necessary to complete the repair. (Ord. 1794 § 9, 2017; Ord. 1704 § 3, 2014; Ord. 835 § 5.1, 1989).

17.20.190 Specific standards.

In all areas of special flood hazards where base flood elevation data has been provided as set forth in OHMC 17.20.070 or 17.20.150(2), the following provisions are required:

(1) Residential Construction.

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

(b) 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:

(i) A minimum of two openings having a total net area of not less than one square inch for every square foot of enclosed area subject to flooding shall be provided;

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

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

(iv) Additional standards are clarified in FEMA Technical Bulletin 11-01, “Crawlspace for Buildings Located in Special Flood Hazard Areas.”

(2) Nonresidential Construction. New construction and substantial improvement of any commercial, industrial or other nonresidential structure shall either have the lowest floor, including basement, elevated to or above the level of the base flood elevation; or, together with attendant utility and sanitary facilities, shall:

(a) Be floodproofed so that below one foot above the base flood level the structure is watertight with walls substantially impermeable to the passage of water;

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

(c) Be certified by a registered professional engineer or architect that the design and methods of construction are in 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 OHMC 17.20.150(3)(b);

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

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

(3) Critical Facility. Construction of new critical facilities shall be, to the extent possible, located outside the limits of the base floodplain. Construction of new critical facilities shall be permissible within the base floodplain if no feasible alternative site is available. Critical facilities constructed within the base floodplain shall have the lowest floor elevated to three feet or more above the level of the base flood elevation at the site. Floodproofing and sealing measures must be taken to ensure that toxic substances will not be displaced by or released into floodwaters. Access routes elevated to or above the level of the base floodplain shall be provided to all critical facilities to the extent possible.

(4) Manufactured Homes. All manufactured homes to be placed or substantially improved 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 OHMC 17.20.180(1)(b).

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

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

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

(c) Meet the requirements of subsection (4) of this section and be securely anchored to an adequately anchored foundation system in accordance with the provisions of OHMC 17.20.180(1)(b). (Ord. 1704 § 4, 2014; Ord. 1472 § 1, 2006; Ord. 835 § 5.2, 1989).

17.20.200 Floodways.

Located within areas of special flood hazard established in OHMC 17.20.070 are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of floodwaters which carry debris, potential projectiles, and erosion potential, the following provisions apply:

(1) Prohibit encroachments, including fill, new construction, substantial improvements, and other development unless certification by a registered professional engineer or architect is provided demonstrating, through hydrologic and hydraulic analyses performed in accordance with standard engineering practice, that encroachments shall not result in any increase in flood levels during the occurrence of the base flood discharge.

(2) Construction or reconstruction of residential structures is prohibited within designated floodways, except for (a) repairs, reconstruction, or improvements to a structure which do not increase the ground floor area; and (b) repairs, reconstruction or improvements to a structure, the cost of which does not exceed 50 percent of the market value of the structure either (i) before the repair, reconstruction, or repair is started, or (ii) if the structure has been damaged, and is being restored, before the damage occurred. Work done on structures to correct existing violations of state or local health, sanitary, or safety code specifications which have been identified by the building official and which are the minimum necessary to assure safe living conditions to comply with existing health, sanitary, or safety codes or to structures identified as historic places shall not be included in the 50 percent.

(3) If subsection (1) of this section is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of this article. (Ord. 1794 § 10, 2017; Ord. 1472 § 1, 2006; Ord. 835 § 5.3, 1989).

17.20.210 Coastal high hazard areas.

In all areas of special flood hazards designated as Zone V1-30, VE and/or V, the following provisions shall apply:

(1) All new construction and substantial improvements 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. 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 licensed design professional is required to provide 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.

(2) Provide elevation certifications in accordance with the North American Vertical Datum (NAVD 88) protocol of the bottom of the lowest structural member of the lowest floor (excluding pilings and columns) of all new and substantially improved structures and indicate whether or not such structures contain a basement. The floodplain administrator shall maintain a record of all such information.

(3) All new construction shall be located landward of the reach of mean high tide.

(4) All new construction and substantial improvements shall 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 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 when the registered engineer or architect certifies that the design proposed meets the following conditions:

(a) Breakaway wall collapse shall result from water load less than that which would occur during the base flood; and

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

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

(5) The use of fill for structural support of buildings is prohibited.

(6) Manmade alteration of sand dunes is prohibited.

(7) 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 OHMC 17.20.190(4).

(8) Recreational vehicles placed on sites within Zones V1-30, V, and VE on the community’s FIRM either:

(a) Be on the site for fewer than 180 consecutive days; or

(b) Be fully licensed and ready for highway use, on its wheels or jacking system, 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 OHMC 17.20.120 (development permit required) and subsections (1) through (6) of this section. (Ord. 1794 § 11, 2017).

17.20.220 Wetlands management.

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

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

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

(3) Request technical assistance from the Department of Ecology in identifying wetland areas. Existing wetland map information from the National Wetlands Inventory (NWI) can be used in conjunction with the community’s FIRM to prepare an overlay zone indicating critical wetland areas deserving special attention. (Ord. 1794 § 12, 2017; Ord. 835 § 5.4, 1989. Formerly 17.20.210).

17.20.230 Encroachments.

The cumulative effect of any proposed development, where 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. 1794 § 13, 2017; Ord. 835 § 5.5, 1989. Formerly 17.20.220).

Prior legislation: Ord. 481.