The purpose of the flood hazard overlay zone is to regulate the use of those areas subject to periodic flooding, to promote the public health, safety, and general welfare and to minimize public and private losses due to flood conditions.
(Ord. 24-05, 6/5/2024)
In advancing these principles and the general purposes of the comprehensive plan and zoning ordinance, the specific objectives of this zone are as follows:
A. 
To combine with the present zoning requirements certain restrictions made necessary for the known flood hazard areas to promote the general health, welfare and safety of the City;
B. 
To 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;
C. 
To minimize the need for rescue and relief efforts associated with flooding;
D. 
To help maintain a stable tax base by providing for sound use and development in flood-prone areas and to minimize prolonged business interruptions;
E. 
To minimize damage to public facilities and utilities located in flood hazard areas;
F. 
To ensure that potential home and business buyers are notified that property is in a flood area;
G. 
To ensure that those who occupy the areas of special flood hazard assume responsibility for their actions.
(Ord. 24-05, 6/5/2024)
The areas of special flood hazard identified by the Federal Emergency Management Agency through a scientific and engineering report entitled "The Flood Insurance Study for Clatsop County, Oregon and Incorporated Areas", dated June 20, 2018" with accompanying Flood Insurance Rate Maps and Flood Boundary Maps and any revision thereto, is adopted by reference and declared to be a part of this chapter. The flood insurance study is on file at the City Hall.
(Ord. 24-05, 6/5/2024)
No structure or land shall be located, extended, converted, or altered without full compliance with the terms of the ordinance codified in this chapter and other applicable regulations.
(Ord. 24-05, 6/5/2024)
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 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, or any officer or employee thereof, for any flood damages that result from reliance on this chapter or any administrative decision lawfully made thereunder.
(Ord. 24-05, 6/5/2024)
A building/development permit is required in conformance with the provisions of this chapter. The permit is for all structures including manufactured homes, as set forth in Section 17.98.030, and for all developments including fill and other activities, also as defined in Section 17.98.030. Application for a building/development permit shall be made to the building official on forms furnished by him or her and shall specifically include the following information:
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 method for any nonresidential structure meets the floodproofing criteria in Section 17.98.190;
D. 
Description of the extent to which any watercourse will be altered or relocated as a result of proposed development.
(Ord. 24-05, 6/5/2024)
A. 
Duties of Building Official. The building official is designated to administer and implement the flood hazard overlay zone. The duties of the building official include, but are not limited to, permit review:
1. 
Review of all development 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.
B. 
Use of Other Base Flood Data. When base flood elevation data has not been provided in accordance with Section 17.98.050, Basis for establishment of special flood hazard areas, the building official shall obtain, review, and reasonably utilize any base flood elevation data available from a federal, state or other source in order to administer Section 17.98.180, Residential construction, and Section 17.98.190, Nonresidential construction.
C. 
Information to be Obtained and Maintained. Where base flood elevation data is provided through the flood insurance study or required as in subsection B of this section, the building official shall:
1. 
Verify and record actual elevation (in relation to mean sea level) of the lowest floor (including basement 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:
a. 
Verify and record the actual elevation (in relation to mean sea level), and
b. 
Maintain the floodproofing certifications required in Section 17.98.080(C);
3. 
Maintain for public inspection all records pertaining to the provisions of this chapter;
4. 
In coastal high-hazard areas, obtain certification 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.
D. 
Alteration of Watercourses. The building official shall:
1. 
Notify adjacent communities and 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 such watercourse so that the flood-carrying capacity is not diminished.
E. 
Interpretation of FIRM Boundaries. The building official shall make interpretations where needed as to the 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 interpretations as provided in Section 17.98.100.
(Ord. 24-05, 6/5/2024)
A. 
Appeals. The planning commission, pursuant to Chapter 17.18, shall hear and decide appeals when it is alleged there is an error in any interpretation, requirement, decision, or determination in the enforcement or administration of this chapter.
1. 
In considering an appeal, the planning commission shall consider all technical evaluations, all relevant factors, standards specified in other sections of this chapter, and
a. 
The danger that materials may be swept onto other lands to the injury of others;
b. 
The danger to life and property due to flooding or erosion damage;
c. 
The susceptibility of the proposed facility and its contents to flood damage and the effect of such damage on the individual owner;
d. 
The importance of the services provided by the proposed facility to the community;
e. 
The necessity to the facility of a waterfront location, where applicable;
f. 
The availability of alternative locations for the proposed use which are not subject to flooding or erosion damage;
g. 
The compatibility of the proposed use with existing and anticipated development;
h. 
The relationship of the proposed use to the comprehensive plan and floodplain management program for that area;
i. 
The safety of access to the property in times of flood for ordinary and emergency vehicles;
j. 
The expected heights, velocity, duration, rate of rise, and sediment transport of the flood waters 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.
2. 
The decision of the planning commission may be appealed pursuant to Chapter 17.18.
B. 
Variances. Variances shall be considered by the planning commission pursuant to the procedural requirements of Chapter 17.16.
1. 
Variances as interpreted in the National Flood Insurance Program are based on the general zoning law principle that they pertain to a physical piece or 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.
2. 
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 variance criteria and otherwise complies with Section 17.98.120.
3. 
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 the standards in subsection (A)(1) of this section have been fully considered. As the lot size increases the technical justification required for issuing the variance increases.
4. 
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 variance criteria and standards of this section provided that the alteration will not preclude the structure's continued designation as a "historic structure."
5. 
Variances shall not be issued within a designated floodway if any increase in flood levels during the base flood discharge would result.
6. 
Variances shall be granted only if, on the basis of the application, investigation and evidence submitted by the applicant, all of the following criteria are met:
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, or conflict with existing local laws or ordinances; and
d. 
The variance is the minimum necessary, considering the flood hazard, to afford relief.
7. 
Upon consideration of the factors of subsection (A)(1) above and the purposes of this chapter, the planning commission may attach such conditions to the granting of variances as it deems necessary to further the purposes of this chapter.
8. 
The action of the planning commission may be appealed pursuant to Chapter 17.18.
C. 
The 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. 24-05, 6/5/2024)
A. 
All new construction and substantial improvement 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 (reference FEMA's "Manufactured Home Installation in Flood Hazard Areas" guidebook for additional techniques). 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.
(Ord. 24-05, 6/5/2024)
A. 
All new construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage.
B. 
All new construction or substantial improvements shall be constructed by methods and practices that minimize flood damage.
C. 
Electrical, heating, ventilation, plumbing and air-conditioning equipment and other service facilities shall be elevated to one foot above flood level so as to prevent water from entering or accumulating within the components during conditions of flooding.
(Ord. 24-05, 6/5/2024)
A. 
Crawlspace Construction. Below-grade crawlspaces are allowed subject to the following standards as found in FEMA Technical Bulletion 11-01, Crawlspace Construction for Buildings Located in Special Flood Hazard Areas:
1. 
The building must be designed and adequately anchored to resist flotation, collapse, and lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy. Hydrostatic loads and the effects of buoyancy can usually be addressed through the required openings stated in subsection B below. Because of hydrodynamic loads, crawlspace construction is not allowed in areas with flood velocities greater than five feet per second unless the design is reviewed by a qualified design professional, such as a registered architect or professional engineer. Other types of foundations are recommended for these areas.
2. 
The crawlspace is an enclosed area below the base flood elevation (BFE) and as such, must have openings that equalize hydrostatic pressures by allowing the automatic entry and exit of floodwaters. The bottom of each flood vent opening can be no more than one foot above the lowest adjacent exterior grade.
3. 
Portions of the building below the BFE must be constructed with materials resistant to flood damage. This includes not only the foundation walls of the crawlspace used to elevate the building, but also any joists, insulation, or other materials that extend below the BFE. The recommended construction practice is to elevate the bottom of joists and all insulation above BFE.
4. 
Any building utility systems within the crawlspace must be elevated above BFE or designed so that floodwaters cannot enter or accumulate within the system components during flood conditions. Ductwork, in particular, must either be placed above the BFE or sealed from floodwaters.
5. 
The interior grade of a crawlspace below the BFE must not be more than two feet below the lowest adjacent exterior grade.
6. 
The height of the below-grade crawlspace, measured from the interior grade of the crawlspace to the top of the crawlspace foundation wall must not exceed four feet at any point. The height limitation is the maximum allowable unsupported wall height according to the engineering analyses and building code requirements for flood hazard areas.
7. 
There must be an adequate drainage system that removes floodwaters from the interior area of the crawlspace. The enclosed area should be drained within a reasonable time after a flood event. The type of drainage system will vary because of the site gradient and other drainage characteristics, such as soil types. Possible options include natural drainage through porous, well-drained soils and drainage systems such as perforated pipes, drainage tiles or gravel or crushed stone drainage by gravity or mechanical means.
8. 
The velocity of floodwaters at the site should not exceed five feet per second for any crawlspace. For velocities in excess of five feet per second, other foundation types should be used.
(Ord. 24-05, 6/5/2024)
A. 
All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of flood waters into the system.
B. 
New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of flood waters into the systems and discharges from the systems into flood waters.
C. 
On-site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding consistent with the Oregon Department of Environmental Quality.
(Ord. 24-05, 6/5/2024)
A. 
All subdivision proposals shall have public utilities and facilities such as sewer, gas, electrical, and water systems located and constructed to minimize flood damage.
B. 
All subdivision proposals shall be consistent with the need to minimize flood damage.
C. 
All subdivision proposals shall have adequate drainage provided to reduce exposure to flood damages.
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).
(Ord. 24-05, 6/5/2024)
Where elevation data is not available either through the flood insurance study or from another authoritative source (Section 17.98.080(B)), 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 the lowest floor at least two feet above the natural grade in these zones may result in higher insurance rates.
(Ord. 24-05, 6/5/2024)
In all areas of special flood hazards (FHO zone) where base flood elevation data has been provided as set forth in Section 17.98.040, Basis for Establishing the Areas of Special Flood Hazard, or Section 17.98.080(B), Use of Other Base Flood Data, the provisions in Sections 17.98.180 through 17.98.240 are required.
(Ord. 24-05, 6/5/2024)
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. 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. 
A minimum of two openings having a total net area of not less than one square inch for every square foot of enclosed area subject to flooding shall be provided.
B. 
The bottom of all openings shall be no higher than one foot above grade.
C. 
Openings may be equipped with screens, louvers, or other coverings or devices provided that they permit the automatic entry and exit of floodwaters.
(Ord. 24-05, 6/5/2024)
A. 
New construction and substantial improvement of any commercial, industrial, or other nonresidential structure shall either have the lowest floor, including basement, elevated according to Table 2-1 the American Society of Civil Engineers, Flood Resistant Design and Construction Standard (ASCE 24); or, together with attendant utility and sanitary facilities, shall:
1. 
Be floodproofed so that below the base flood level the structure is watertight with walls substantially impermeable to the passage of water;
2. 
Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy;
3. 
Be certified by a registered professional engineer or architect that the design and methods of construction are in accordance with accepted standards of practice for meeting provisions of this subsection based on their development and/or review of the structural design, specification and plans. Such certifications shall be provided to the official as set forth in Section 17.98.080(C)(2)(b).
B. 
Nonresidential structures that are elevated, not floodproofed, must meet the same standards for space below the lowest floor as described in Section 17.98.180.
C. 
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 constructed to the base flood level will be rated as one foot below that level).
(Ord. 24-05, 6/5/2024)
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 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.
(Ord. 24-05, 6/5/2024)
All manufactured homes to be placed or substantially improved within zones on the FIRM shall comply with the following:
A. 
The ground area reserved for the placement of a manufactured dwelling shall be a minimum of 12 inches above BFE unless the foundation walls are designed to automatically equalize hydrostatic 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:
1. 
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;
2. 
The bottom of all openings shall be no higher than one foot above grade; and
3. 
Openings may be equipped with screens, louvers, or other coverings or devices provided that they permit the automatic entry and exit of floodwaters.
B. 
The bottom of the longitudinal chassis frame beam in A zones, and the bottom of the lowest horizontal structural member supporting the dwelling in V zones shall be a minimum of 12 inches above base flood elevation.
C. 
The manufactured dwelling shall be anchored to prevent flotation collapse and lateral movement during the base flood. Anchoring methods may include, but are not limited to, use of over-the-top or frame ties to ground anchors.
D. 
Electrical crossover connections shall be a minimum of 12 inches above the base flood elevation.
(Ord. 24-05, 6/5/2024)
Recreational vehicles placed on sites within zone AE on the FIRM shall 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 17.98.210 and the elevation and anchoring requirements for manufactured homes.
(Ord. 24-05, 6/5/2024)
Coastal high-hazard areas (V zones) are located within the areas of special flood hazard established in Section 17.98.030. These areas have special flood hazards associated with high velocity waters from tidal surges and, therefore, in addition to meeting all provisions in this chapter, the following provisions also apply:
A. 
1. 
In all new construction and substantial improvements in VE zones 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 subsections (A)(1)(a) and (A)(1)(b) of this section.
B. 
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 VE zones and whether or not such structures contain a basement. The local administrator shall maintain a record of all such information.
C. 
All new construction shall be located landward of the reach of mean high tide.
D. 
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 latticework or insect screening intended to collapse under wind and water loads without causing collapse, displacement, or other structural damage to the elevated portion of the building or supporting foundation system. For the 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:
1. 
Breakaway wall collapse shall result from a water load less than that which would occur during the base flood; and
2. 
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).
E. 
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.
F. 
The use of fill for structural support of buildings is prohibited.
G. 
Manmade alteration of sand dunes which would increase potential flood damage is prohibited.
H. 
All manufactured homes to be placed or substantially improved within VE zones shall meet the standards of subsections A through G of this section.
I. 
Recreational vehicles placed on sites within VE zones on the FIRM shall 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 of subsections A through G and a permit, pursuant to Section 17.98.070, is obtained.
(Ord. 24-05, 6/5/2024)
Shallow flooding areas appear on FIRMs as AO zones with depth designations. The base flood depths in these zones range from one to three feet where a clearly defined channel does not exist, or where the path of flooding is unpredictable and where velocity flow may be evident. Such flooding is usually characterized as sheet flow. In these areas, the following provisions apply:
A. 
New construction and substantial improvements of residential structures within AO zones shall have the lowest floor (including basement) elevated above the highest adjacent grade of the building site, a minimum of one foot above the depth number specified on the FIRM (at least two feet if no depth number is specified);
B. 
New construction and substantial improvement of nonresidential structures shall either:
1. 
Have the lowest floor (including basement) elevated above the highest adjacent grade of the building site, to or above the depth number specified on the FIRM (at least two feet if no depth number is specified), or
2. 
Together with attendant utility and sanitary facilities, be completely floodproofed to or above that level so that any space below that level is watertight with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and effects of buoyancy. If this method is used compliance shall be certified by a registered professional engineer or architect;
C. 
Adequate drainage paths around structures on slopes are required to guide floodwaters around and away from proposed structures;
D. 
Recreational vehicles placed on sites within AO Zones on the community's FIRM either:
1. 
Be on the site for fewer than 180 consecutive days, and
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 of subsections A, B, and C; and the elevation and anchoring requirements for manufactured homes.
(Ord. 24-05, 6/5/2024)
Restrictions regarding height, rear yards, side yards, front yard setback, minimum lot area, signs, vision clearance and parking space shall be the same as set forth in each specific zone located within the flood hazard overlay zone area.
(Ord. 24-05, 6/5/2024)
It is unlawful to erect, alter, maintain or establish in a flood hazard overlay zone any building, use or occupancy not permitted or allowed in the foregoing provisions, except existing nonconforming uses, which may continue as provided in Chapter 17.88.
(Ord. 24-05, 6/5/2024)
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) are subject to Chapter 17.20, Enforcement. Nothing herein contained shall prevent the city from taking such other lawful action as is necessary to prevent or remedy any violation.
(Ord. 24-05, 6/5/2024)
This chapter is not intended to repeal, abrogate, or impair any existing easements, covenants, or deed restrictions. However, where this chapter and another ordinance, easement, covenant, or deed restriction conflict or overlap, whichever imposes the more stringent restrictions shall prevail.
(Ord. 24-05, 6/5/2024)