City of Warrenton, OR Chapter 16.88 FLOOD HAZARD OVERLAY (FHO) DISTRICT

§ 16.88.010 Purpose.

The purpose of the FH Overlay District is to regulate the use of those areas that are subject to periodic flooding in order to promote the public health, safety, general welfare, and to minimize public and private losses due to flood conditions. FEMA's FIRM map shows the flood areas in Warrenton being in the FIRM category "A and AE" in specific areas by provisions designed to:

A. Combine with other zoning requirements, certain restrictions made necessary for the known flood hazard areas to promote the general health, welfare and safety of the City;

B. Protect human life and health;

C. Prevent the establishment of certain structures and land uses in areas unsuitable for human habitation because of the danger of flooding, unsanitary conditions or other hazards;

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

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

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

G. Minimize prolonged business interruptions;

H. 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;

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

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

§ 16.88.020 General Provisions.

A. Areas Affected by FH Overlay District. This district shall apply to all areas of special flood hazards within the jurisdiction of Warrenton. Since the FH overlay district is an overlay zone, one or more other zoning districts will also regulate the use of land in areas of special flood hazards.

B. Basis for Establishing the Areas of Special Flood Hazards. The areas of special flood hazard identified by the Federal Insurance Administration in a scientific and engineering report entitled "The Flood Insurance Study for Clatsop County, Oregon and Incorporated Areas," dated September 17, 2010, with accompanying flood insurance maps are hereby adopted by reference and declared to be a part of this chapter. The Flood Insurance Study is on file at the Warrenton City Hall. The best available information for flood hazard area identification as outlined in Section 16.88.030(B) shall be the basis for regulation until a new FIRM is issued which incorporates the data utilized under Section 16.88.030(B).

C. Prohibited Uses. In an FH overlay district it shall be unlawful to erect, alter, maintain or establish, in an FH overlay district, any building, use, or occupancy not permitted by the provisions of this or any other applicable zoning district except existing nonconforming uses and structures, which may continue as specified in Chapter 16.276.

D. Warning and Disclaimer of Liability. The degree of flood protection required by this ordinance 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 man-made 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 Warrenton, 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.

E. 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. Violations 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 $1,000.00 for each violation and in addition shall pay all costs and expenses involved in the case. Nothing herein contained shall prevent the Community Development Director from taking such other lawful action as is necessary to prevent or remedy any violation.

F. 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, state building codes, easement, covenant, or deed restriction conflict or overlap, whichever imposes the more stringent restrictions shall prevail.

G. Severability. If any section, clause, sentence, or phrase of this chapter is held to be invalid or unconstitutional by any court of competent jurisdiction, then said holding shall in no way affect the validity of the remaining portions of this chapter.

H. 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 or repeal any other powers granted under state statutes, and rules including state building codes.

I. 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.

§ 16.88.030 Administration.

A. Establishment of Floodplain Development Permit. A floodplain development permit, in addition to any regular building permit and/or grading permit that may be required, shall be obtained before construction or development begins in any area of special flood hazard established in Section 16.88.010. The permit shall be for all structures including manufactured homes, as set forth in the "definitions," and for all development including fill and other activities.

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

1. Description of proposed development.

2. Size and location of proposed development (site plan required).

3. Base flood elevation at the site.

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

5. Elevation to which floodproofing has occurred (if any).

6. Certification by a registered professional engineer or architect that the floodproofing methods for any nonresidential structure meet the floodproofing criteria in Section 16.88.040.

7. Elevation in relation to mean sea level of floodproofing in any structure.

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

9. FEMA/NFIP elevation certificate completed by a land surveyor, engineer, or architect who is authorized by law to certify elevation information (for all new structures and substantial improvements unless otherwise exempt from this requirement by state or federal law).

C. Duties and Responsibilities. The duties of the Community Development Director or designee shall include, but not be limited to:

1. Review all building permits to determine that the permit requirements and conditions of this chapter have been satisfied.

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

3. Review all development permits in the area of special flood hazard to determine if the proposed development adversely affects the flood carrying capacity of the area.

D. Use of Other Base Flood Data. When base flood elevation data has not been provided in accordance with Section 16.88.020, the Community Development Director or designee shall obtain, review, and reasonably utilize any base flood elevation floodway data available from a federal, state, or other source, in order to administer Section 16.88.030.

E. Information to be Obtained and Maintained by Planning and Building Department.

1. Where base flood elevation data is provided through the Flood Insurance Study, FIRM, or required as in Section 16.88.030, the building official shall verify, obtain and record the actual elevation (in relation to mean sea level) of the lowest flood (including basements and below-grade crawlspaces) of all new or substantially improved structures, and whether or not the structure contains a basement.

2. For all new or substantially improved floodproofed structures where base flood elevation data is provided through the Flood Insurance Study, FIRM, or as required in Section 16.88.030:

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

b. Maintain the floodproofing certifications required in Section 16.88.030.

3. Maintain for public inspection all records pertaining to the provisions of this chapter.

4. In coastal high hazard areas, certification shall be obtained from a registered professional engineer or architect that the structure is securely anchored to adequately anchored pilings or columns in order to withstand velocity waters.

F. Interpretation of FIRM Boundaries. Interpretations where needed, as to the exact location of the boundaries of the areas of special flood hazards (i.e., 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 reasonable opportunity to appeal the interpretation to the Planning Commission.

G. Alteration of Watercourses.

1. Notify adjacent communities, the Department of Land Conservation and Development and other appropriate state and federal agencies, 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.

H. Variance Procedures.

1. Variances shall be issued or denied in accordance with this section.

2. Conditions for Variances.

a. Generally, the only condition under which a variance from the elevation standard may be issued is for new construction and substantial improvements to be erected on a lot of one-half acre or less in size contiguous to and surrounded by lots with existing structures constructed below the base flood level. As the lot size increases the technical justification required for issuing the variance increases.

b. Variances may be issued for the rehabilitation, or restoration of structures listed on the National Register of Historic Places or the Statewide Inventory of Historic Properties, without regard to the procedures set forth in this section provided that the alteration will not preclude the structure's continued designation as a "historic structure."

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

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

e. Variances shall only be issued upon:

i. A showing of good and sufficient cause;

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

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

iv. A determination that the variance is the minimum necessary, considering the flood hazard, to afford relief.

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

g. Variances may be issued for nonresidential building(s) 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 and otherwise complies with general standards.

3. 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.

I. Appeals.

1. Appeals will be conducted in accordance with Section 16.208.040 of this Code, and

a. The hearings body as established by Section 16.208.040 shall hear and decide appeals and requests for variances from the requirements of this chapter.

b. The hearings body shall hear and decide appeals when it is alleged there is an error in any requirement, decision, or determination made by the governing body in the enforcement or administration of this chapter.

c. Those aggrieved by the decision of the governing body, may appeal such decision to the appropriate hearings body, as provided in Section 16.208.040 of this Code.

2. In passing upon such applications, the hearings body shall consider all technical evaluations, all relevant factors, standards specified in other sections of this chapter, and the:

a. Danger that materials may be swept onto other lands to the injury of others;

b. Danger to life and property due to flooding or erosion damage;

c. Susceptibility of the proposed facility and its contents to flood damage and the effect of such damage on the individual owner;

d. Importance of the services provided by the proposed facility to the community;

e. Necessity to the facility of a waterfront location, where applicable;

f. Availability of alternative locations for the proposed use which are not subject to flooding or erosion damage;

g. Compatibility of the proposed use with existing and anticipated development;

h. Relationship of the proposed use to the Comprehensive Plan and floodplain management program for that area;

i. Safety of access to the property in times of flood for ordinary and emergency vehicles;

j. 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. 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.

3. Upon consideration of the factors and the purposes of this chapter, the hearings body may attach such conditions to the granting of variances as it deems necessary to further the purposes of this chapter.

4. The Planning and Building Department shall maintain the records of all appeal actions and report any variances to the Federal Insurance Administration upon request.

(Ord. 1220 § 2, 2018)

§ 16.88.040 Standards for Flood Hazard Reduction.

In all areas of special Flood Hazard Overlay Zone (FHO zone), the following standards are required:

A. Anchoring.

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

2. All manufactured homes shall 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 and frame ties to ground anchors. (Reference FEMA's "Manufactured Home Installation in Flood Hazard Areas" guidebook for additional techniques.)

3. A certificate signed by a registered architect or engineer which certifies that the anchoring system is in conformance with FEMA regulations shall be submitted prior to final inspection approval.

B. Construction Materials and Methods.

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

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

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

C. Utilities.

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

2. 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; and

3. On-site waste disposal systems shall be located to avoid impairment of them or contamination from them during flooding consistent with the Oregon Department of Environmental Quality (DEQ).

D. Subdivision Proposals.

1. All subdivision proposals shall be consistent with the need to minimize flood damage.

2. All subdivision proposals shall have public utilities and facilities such as sewer, gas, electrical, and water systems located and constructed to minimize or eliminate flood damage.

3. All subdivision proposals shall have adequate drainage provided to reduce exposure to flood damage.

4. Where base flood elevation data has not been provided or is not available from another authoritative source, it shall be generated for subdivision proposals and other proposed developments which contain at least 50 lots or five acres (whichever is less).

E. Alteration of Watercourses.

1. No watercourse shall be altered until a maintenance plan is provided which assures that the flood-carrying capacity of altered or relocated portions of the watercourse is not diminished.

2. The Community Development Director shall notify the Oregon Department of Land Conservation and Development prior to any alteration or relocation of a watercourse, and submit evidence of such notification to the Federal Insurance Administration.

F. Review of Building Permits. Where elevation data is not available either through the Flood Insurance Study, FIRM, 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.

G. Specific Standards, Residential and Nonresidential Construction. In all areas of special flood hazards (FH overlay district) where base flood elevation data has been provided as set forth in Section 16.88.020, the following provisions shall apply unless a variance is granted in accordance with Section 16.88.030 and Chapter 16.272.

1. Residential Construction.

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

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 be either certified by a registered professional engineer, 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.

2. Nonresidential Construction.

a. New construction and substantial improvement of any commercial, industrial, or other nonresidential structure shall either have the lowest floor, including basement, elevated to a minimum of one foot above the base flood elevation; or, together with attendant utility and sanitary facilities, shall:

i. Be floodproofed so that below the base flood level the structure is watertight with walls substantially impermeable to the passage of water;

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, specification and plans. Such certifications shall be provided to the building official as set forth in Chapter 16.244;

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

v. Applicants floodproofing nonresidential buildings shall be notified that the 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).

b. Critical Facility. Construction of new critical facilities shall be, to the extent possible, located outside the limits of the Special Flood Hazard Area (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 base flood elevation shall be provided to all critical facilities to the extent possible.

H. Manufactured Homes/Dwellings.

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

a. Outside of a manufactured home park or subdivision;

b. In a new manufactured home park or subdivision;

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

d. In an existing manufactured home park or subdivision on which a manufactured home has incurred "substantial damage" shall be elevated on a permanent foundation such that the finished floor of the manufactured home is elevated to a minimum 18 inches (46 cm)* above the base flood elevation, is securely anchored to an adequately designed foundation system to resist flotation, collapse and lateral movement, and electrical crossover connections are a minimum of 12 inches above BFE.

2. Manufactured homes to be placed or substantially improved on sites in an existing manufactured home park or subdivision within Zones Al-30, AH, and AE on the community's FIRM that are not subject to the above manufactured home provisions shall be elevated so that either:

a. The lowest floor of the manufactured home is elevated to a minimum of 18 inches (46 cm) above the base flood elevation; or

b. The manufactured home chassis is supported by reinforced piers or other foundation elements of at least equivalent strength that are no less than 36 inches in height above grade and be securely anchored to an adequately designed foundation system to resist flotation, collapse, and lateral movement.

* See 2002 Oregon Manufactured Dwelling and Parks Specialty Code, Chapter 3. The code also requires that the top of the dwelling stand be at least 12 inches above BFE.

I. Specific Standards, Manufactured Dwelling Parks or Subdivisions.

1. All subdivision proposals shall be consistent with the need to minimize flood damage;

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

3. All subdivision proposals shall have adequate drainage provided to reduce exposure to flood damage; and

4. Where base flood elevation data has not been provided or is not available from another authoritative source, it shall be generated for subdivision proposals and other proposed developments which contain at least 50 lots or five acres (whichever is less).

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

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

2. Be fully licensed and ready for highway use, on its wheels or jacking system, is attached to the site only by quick disconnect type utilities and security devices, and has no permanently attached additions; or

3. Meet the requirements in Section 16.88.030(B)(9), and the elevation and anchoring requirements for manufactured homes.

K. Review of Flood Hazard 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.

L. Flood Hazard, Park and Open Space Dedications. Where fill and/or development is allowed within or adjacent to the 100-year floodplain outside the zero-foot rise floodplain, and the Comprehensive Plan designates the subject floodplain for park, open space, or trail use, the City may require the dedication of sufficient open land area for a greenway adjoining or within the floodplain. When practicable, this area shall include portions at a suitable elevation for the construction of a pedestrian/bicycle pathway within the floodplain in accordance with the City's adopted TSP for trails, pedestrian, and bikeway, as applicable. The City shall evaluate individual development proposals and determine whether the dedication of land is justified based on the development's impact and shall be consistent with Chapter 16.136.

M. Temporary Encroachments in the Floodway for the Purposes of Bridge Construction and Repair.

1. This use shall comply with this chapter, Section 16.208.040 (Type II Procedure), and Chapter 16.240 (Miscellaneous Permits) prior to issuance of any permits.

2. The temporary permit shall state the number of days the structure or other development will be on the site. If a longer period is required, a new permit shall be issued.

3. A flood warning system for the project should be in place to allow equipment to be evacuated from the site and placed outside the floodplain.

4. Placement of equipment in the floodway should be restricted to only equipment which is absolutely necessary for the purposes of the project. All other accessory equipment and temporary structures (i.e., construction trailers) should be restricted from the floodway. Structures should be placed on site so that flood damages are minimized. Anchoring the construction trailers in case evacuation is not practical.

N. Coastal High Hazard Areas. Located within areas of special flood hazard established in Section 16.88.030(B) 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 this title the following provisions shall also apply:

1. All new construction and substantial improvements in Zones V1-V30 and VE (V if base flood elevation data is available) shall be elevated on pilings and columns so that:

a. The bottom of the lowest horizontal structural member of the lowest floor (excluding the pilings or columns) is elevated a minimum of one foot 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);

2. 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 paragraphs (a) and (b) of this subsection.

3. Obtain the elevation (in relation to mean sea level) of the bottom of the lowest structural member of the lowest floor (excluding pilings and columns) of all new and substantially improved structures in Zones V1-30, VE, and V, and whether or not such structures contain a basement. The local administrator shall maintain a record of all such information.

4. All new construction shall be located landward of the reach of mean high tide.

5. Provide that all new construction and substantial improvements have the space below the lowest floor either free of obstruction or constructed with non-supporting breakaway walls, open wood lattice-work, or insect screening intended to collapse under wind and water loads without causing collapse, displacement, or other structural damage to the elevated portion of the building or supporting foundation system. For the purpose of this section, a breakaway wall shall have a design safe loading resistance of not less than 10 and no more than 20 pounds per square foot. Use of breakaway walls which exceed a design safe loading resistance of 20 pounds per square foot (either by design or when so required by local or state codes) may be permitted only if a registered professional engineer or architect certifies that the designs proposed meet the following conditions:

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

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

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

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

8. Prohibit man-made alteration of sand dunes which would increase potential flood damage.

9. All manufactured homes to be replaced or substantially improved within Zones V1-V30, V, and VE on the community's FIRM shall meet the standards of paragraphs (1) through (8) of this subsection.

10. 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;

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

c. Meet the requirements of Section 16.88.030(A) and paragraphs (1) through (8) of this subsection.

(Ord. 1175-A § 11, 2013; Ord. 1220 §§ 3, 4, 2018)