A.

The purpose of the Floodplain Overlay District (FPO) is to promote the public health, safety, and general welfare, and to minimize public and private losses due to flooding in special flood hazard areas by provisions designed to:

1.

Protect human life and health;

2.

Minimize the expenditure of public money for costly flood control projects;

3.

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

4.

Minimize prolonged business interruptions;

5.

Minimize damage to public facilities and utilities such as water and gas mains, electric, telecommunications and sewer lines, and streets and bridges, located in special flood hazard areas;

6.

Help maintain a stable tax base by providing for the sound use and development of special flood hazard to minimize blight caused by flooding;

7.

Notify potential buyers that property is in a special flood hazard area;

8.

Notify those who occupy special flood hazard areas that they assume responsibility for their actions;

9.

Participate in and maintain eligibility for flood insurance and disaster relief.

10.

Implement the floodplain policies in the city comprehensive plan.

B.

To accomplish its purposes, the Floodplain Overlay District includes the following methods and provisions for reducing Hood losses:

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 development vulnerable to floods, including facilities which serve development, be protected against flood damage at the time of initial construction.

3.

Controlling the alteration of natural flood plains, stream channels, and natural protective barriers, which help accommodate or channel flood waters.

4.

Controlling filling, grading, dredging, and other development which may increase flood damage.

5.

Preventing or regulating the construction of flood barriers which will unnaturally divert flood waters or may increase flood hazards in other areas.

6.

Coordinating and supplementing the provisions of the state building code with local land use and development regulations.

(Ord. No. 2023-03, § 2(Exh. B), 8-21-2023)

For purposes of the Floodplain Overlay District, the following terms shall mean:

"Accessory structure" means a structure which is less than two hundred (200) square feet in gross floor area, is less than ten (10) feet in height, is detached from and is on the same parcel of property as the principal structure, and the use of which is incidental to the use of the principal structure.

"Appeal" means a request for a review of:

1.

The interpretation of any provision of Section 16.280, or

2.

The decision for a flood plain development permit that includes the exercise of discretion, or

3.

The decision for a variance to the standards of the Floodplain Overlay District.

"Area of shallow flooding" means a designated Zone AO, AH, AR/AO or AR/AH on a community's Flood Insurance Rate Map (FIRM) with a one percent or greater annual change of flooding to an average depth of one to three (3) feet where a clearly defined channel does not exist, where the path of flooding is unpredictable, and where velocity flow may be evident. Such flooding is characterized by ponding or sheet flow.

"Area of special flood hazard" means land in the floodplain within a community subject to a one percent or greater chance of flooding in any given year. Designation on the flood insurance rate map (FIRM) always includes the letter A. It is shown on the FIRM as Zone A, AO, AH, A1-30, AE, A99 or AR. "Special flood hazard area" is synonymous in meaning and definition with the phrase area of special flood hazard."

"Base flood" means the flood having a one percent change of being equaled or exceeded in any given year.

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

"Basement" means any area of a building having its floor subgrade (below ground level) on all sides.

"Below-grade crawl space" means an enclosed area below the base flood elevation in which the interior grade is not more than two (2) feet below the lowest adjacent exterior grade, and the height, measured from the interior grade of the crawlspace to the top of the crawlspace foundation, does not exceed four (4) feet at any point.

"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 nursing homes, hospitals, police, fire and emergency response installations, and installations which produce, use or store hazardous materials or hazardous waste.

"Development" means any man-made change to improved or unimproved real estate, including but not limited to buildings or other structures, mining, dredging, filling, grading, paving, excavation, drilling operations, or storage of equipment or materials.

"Elevated building" means, for insurance purposes, a non-basement building which has its lowest elevated floor raised above ground level by foundation walls, shear walls, post, piers, pilings, or columns.

"Encroachment" means any obstruction in the area of special flood hazard which affects flood flows.

"Existing manufactured home park or manufactured home subdivision" means a manufactured home park or manufactured home subdivision for which the construction of facilities for servicing the spaces or lots on which the manufactured homes are to be affixed (including, at a minimum, the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pad) is completed before the effective date of the ordinance codified in this chapter.

"Expansion to an existing manufactured home park or manufactured home subdivision" means the preparation of additional sites by the construction of facilities for servicing the spaces or lots on which the manufactured homes are to be affixed (including the installation of utilities, the construction of streets, and either final site grading or pouring a concrete pad).

"FEMA" means the Federal Emergency Management Agency, the federal organization responsible for administering the national flood insurance program.

"Fill" means the placement of any material on the land for the purposes of increasing its elevation in relation to that which exists. Fill material includes, but is not limited to, the following: soil, rock, concrete, bricks, wood stumps, wood, glass, garbage, plastics, metal, etc.

"Flood" or "flooding" means:

A.

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

1.

The overflow of inland or tidal waters or

2.

The unusual and rapid accumulation of runoff of surface waters from any source, or

3.

Mudslides, i.e., mudflows, which are proximately caused by flooding as defined in Subsection A, 2, of this definition and are akin to a river of liquid and flowing mud on the surfaces of normally dry land areas, as when earth is carried by a current of water and deposited along the path of the current.

B.

The collapse or subsidence of land along the shore of a lake or other body of water as a result of erosion or undermining caused by waves or currents or water exceeding anticipated cyclical levels or suddenly caused by an unusually high water level in a natural body of water, accompanied by a severe storm, or by an unanticipated force of nature, such as flash flood or an abnormal tidal surge, or by some similarly unusual and unforeseeable event which results in flooding as defined in Subsection A, 1, of this definition.

"Flood elevation study" means an examination, evaluation and determination of flood hazards and, if appropriate, corresponding water surface elevations, or an examination, evaluation and determination of mudslide, i.e., mudflow, and/or flood-related erosion hazards.

"Flood insurance rate map (FIRM)" means the official map of a community on which the Federal Insurance Administrator has delineated both the special flood hazards areas and the risk premium zones applicable to the community. A FIRM that has been made available digitally is a Digital Flood Insurance Rate Map (DFIRM).

"Flood insurance study (FIS)" See "Flood elevation study."

"Floodplain or flood prone area" means any land area susceptible to being inundated by water from any source. See "Flood or flooding."

"Floodplain administrator" means the community official designated by title to administer and enforce the floodplain management regulations.

"Floodplain management" means the operation of an overall program of corrective and preventive measures for reducing flood damage, including but not limited to emergency preparedness plans, flood control works, and floodplain management regulations.

"Floodplain management regulations" means zoning regulations, subdivision regulations, building codes, health regulations, special purpose regulations including, but not limited to, floodplain, grading and erosion control regulations, and other applications of police power. The term describes such State or local regulations, in any combination thereof, which provide standards for the purpose of flood damage prevention and reduction.

"Floodproofing" means any combination of structural and nonstructural additions, changes, or adjustments to structures which reduce or eliminate risk of flood damage to real estate or improved real property, water and sanitary facilities, structures, and their contents.

"Floodway" means the channel of a river or other watercourse and the adjacent land areas that must be reserved to discharge the base flood without cumulatively increasing the water surface elevation more than a designated height. Also referred to as "Regulatory Floodway."

"Flood fringe" means the area of the floodplain lying outside of the floodway as delineated on the FIRM where encroachment by development will not increase the flood elevation more than one-foot during the occurrence of the base flood discharge.

"Functionally dependent use" means a use which cannot perform its intended purpose unless it is located or carried out in close proximity to water. The term includes only docking facilities, port facilities that are necessary for the loading and unloading of cargo or passengers, and ship building and ship repair facilities, and does not include long term storage or related manufacturing facilities.

"Hazardous material" means the Oregon Department of Environmental Quality definition of hazardous materials to include any of the following:

A.

Hazardous waste as defined in ORS 466.005;

B.

Radioactive waste as defined in ORS 469.300, radioactive material identified by the Energy facility Siting council under ORS 469.605 and radioactive substances defined in ORS 453.005;

C.

Communicable disease agents as regulated by the Oregon Health Division under ORS Chapter 431 and 433.010 to 433.045 and 433.106 to 433.990;

D.

Hazardous substances designated by the United States Environmental Protection Agency (EPA) under Section 311 of the Federal Water Pollution Control Act, P.L. 92-500, as amended;

E.

Substances listed by the United States EPA in Section 40 of the Code of Federal Regulations, Part 302, Table 302.4 (list of Hazardous Substances and Reportable Quantities) and amendments;

F.

Material regulated as a Chemical Agent under ORS 465.550;

G.

Material used as a weapon of mass destruction, or biological weapon;

H.

Pesticide residue;

I.

Dry cleaning solvent as defined by ORS 465.200(9).

"Highest adjacent grade" means the highest natural elevation of the ground surface prior to construction next to the proposed walls of a structure.

"Historic structure" means any structure that is:

A.

Listed individually in the National Register of Historic Places (a listing maintained by the Department of Interior) or preliminarily determined by the Secretary of the Interior as meeting the requirements for individual listing on the National Register;

B.

Certified or preliminarily determined by the Secretary of the Interior as contributing to the historical significance of a registered historic district preliminarily determined by the Secretary to qualify as a registered historic district;

C.

Individually listed on a State inventory of historic places in States with historic preservation programs which have been approved by the Secretary of the Interior; or

D.

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

1.

By an approved State program as determined by the Secretary of the Interior or

2.

Directly by the Secretary of the Interior in States without approved programs.

"Letter of Map Change (LOMC)" means an official FEMA determination, by letter, to amend or revise effective Flood Insurance Rate Maps and Flood Insurance Studies. The following are categories of LOMCs:

A.

"Conditional Letter of Map Amendment (CLOMA)" means FEMA's comment on a proposed structure or group of structures that would, upon construction, be located on existing natural ground above the base (1-percent-cannual-chane) flood elevation on a portion of a legally defined parcel of land that is partially inundated by the base flood.

B.

"Conditional letter of map revision (CLOMR)" means FEMA's comment on a proposed project that would, upon construction, affect the hydrologic or hydraulic characteristics of a flooding source and thus result in the modification of the existing regulatory floodway, the effective base flood elevations, or the special flood hazard area.

C.

"Conditional letter of map revision based on Fill (CLOMR-F)" means FEMA's comment on a proposed project that would, upon construction, result in a modification of the special flood hazard area through the placement of fill outside the existing regulatory floodway.

D.

"Letter of Map Amendment (LOMA)" means an official amendment, by letter, to the Flood Insurance Rate Maps (FIRMs) based on technical data showing that an existing structure, parcel of land or portion of a parcel of land that is naturally high ground, i.e., has not been elevated by fill, above the base flood, that was inadvertently included in the special flood hazard area.

E.

"Letter of map revision (LOMR)" means FEMA's modification to an effective Flood Insurance Rate Map (FIRM), or Flood Boundary and Floodway Map (FBFM), or both. LOMRs are generally based on the implementation of physical measures that affect the hydrologic or hydraulic characteristics of a flooding source and thus result in the modification of the existing regulatory floodway, the effective base flood elevations, or the SFHA. The LOMR officially revises the FIRM or FBFM, and sometimes the Flood Insurance Study (FIS) report, and, when appropriate, includes a description of the modifications. The LOMR is generally accompanied by an annotated copy of the affected portions of the FIRM, FBFM, or FIS report.

F.

"Letter of map revision based on fill (LOMR-F)" means FEMA's modification of the special flood hazard area shown on the Flood Insurance Rate Map (FIRM) based on the placement of fill outside the existing regulatory floodway.

G.

"PMR" means FEMA's physical revision and republication of an effective Flood Insurance Rate Map (FIRM) or Flood Insurance Study (FIS) report. PMRs are generally based on physical measures that affect the hydrologic or hydraulic characteristics of a flooding source and thus result in the modification of the existing regulatory floodway, the effective baes flood elevations, or the special flood hazard area.

"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 non-elevation design requirements of this chapter.

"Manufactured dwelling" 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. The term "manufactured dwelling" does not include a "recreational vehicle" and is synonymous with "manufactured home."

"Manufactured dwelling park" means a parcel or lot (or contiguous parcels or lots) developed with manufactured dwellings placed on designated areas (typically referred to as a "space") and the manufactured dwelling occupant rents the space.

"Manufactured dwelling subdivision" means a subdivision wherein only manufactured dwellings may be placed on the lots created by the subdivision.

"Mean sea level" means, for purposes of the national flood insurance program, the national geodetic vertical datum (NGVD) of 1929, or the North American vertical datum of 1988 (NAVD88) to which base flood elevations shown on a community's flood insurance rate map are referenced.

"Mobile home" means a vehicle or structure, transportable in one or more Sections, which is eight (8) feet or more in width, is thirty-two (32) feet or more in length, is built on a permanent chassis to which running gear is or has been attached, and is designed to be used as a dwelling with or without permanent foundation when connected to the required utilities. Such definition does not include any recreational vehicle as defined in this Section.

"New construction" means a structure for which the "start of construction" commenced on or after the effective date of a floodplain management regulation adopted by the City of Sheridan.

"New manufactured home park or new manufactured home subdivision" means a manufactured home park or manufactured home subdivision for which the construction of facilities for servicing the spaces or lots on which the manufactured homes are to be affixed (including at a minimum, the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads) is started on or after the effective date of the city's original flood plain regulations or amendments to the flood plain regulations.

"Recreational vehicle" means, as defined in ORS 174.101(3), a vehicle with or without motive power, that is designed for use as temporary living quarters and as further defined by rule by the Director of Transportation in OAR 735-022-0140(6) as "Recreational Vehicle" means a vehicle with or without motive power that is designed for use as temporary living quarters, to be easily transported and set up on a daily basis and is any one of the following:

(a)

A vehicle that is eight and one-half (8 ½) feet wide or less and is certified by the manufacturer or builder as complying with the applicable version of the NFPA 1192 or 50IC or ANSI AI 19.2 standards, depending on which standards apply to the year of manufacture, for the construction of recreational vehicles that was in effect at the time of manufacture;

(b)

A vehicle that is eight and one-half (8 ½) feet wide or less and is certified by the applicant as complying with the applicable version of the NFPA 1192 or 50 IC or ANSI AI 19.2 standards if the vehicle is not new and no manufacturer or builder certification is available, depending on which standards apply to the year of manufacture, for the construction of recreational vehicles that were in effect at the time of manufacture; or

(c)

A PMRV as defined in this rule.

"Regulatory floodway." See "Floodway."

"Sheet flow area." See "Area of shallow flooding."

"Special flood hazard area" means "Area of special flood hazard."

"Start of construction" includes substantial improvement, and means the date the building permit was issued, provided the actual start of construction, repair, reconstruction, rehabilitation, addition, placement or other improvement was within one hundred eighty (180) days of the permit date. The actual start means either the first placement or permanent construction of a structure on a site including, but not limited to, the pouring of slabs or footings, the installation of piles, the construction of columns, or any work beyond the stage of excavation; or the placement of a manufactured dwelling 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 foundations or the erection of temporary forms; nor does it include the installation on the property of accessory buildings including, but not limited to, 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 that alteration affects the external dimensions of the building.

"State building code (SBC)" means the combined specialty codes adopted by the State of Oregon.

"Structure" means a walled and roofed buildings, including a gas or liquid storage tank that is principally above ground and a manufactured dwelling.

"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 fifty (50) percent of the market value of the structure before the damage occurred.

"Substantial improvement" means any reconstruction, addition, or other improvements of a structure, the cost of which exceeds fifty (50) percent of the market value of the structure before the "start of construction" of the improvement. This term includes structures which have incurred "substantial damage" regardless of the actual repair work performed. This term does not include either:

A.

Any project for improvement of a structure to correct existing violations of State or local health, sanitary, or safety code regulations which have been identified by the local code enforcement official and which are the minimum necessary to ensure safe living conditions; or

B.

Any alteration of a "historic structure" provided the alteration will not preclude the structure's continued designation as a "historic structure."

"Variance" means a grant of relief from the requirements of the Floodplain Overlay District which permits construction in a manner that would otherwise be prohibited by the Floodplain Overlay District.

"Violation" means the failure of a structure or other development to be fully compliant with the City of Sheridan floodplain management regulations. A structure or other development without an Elevation Certificate, other certifications, or other evidence of compliance required in the Flood Plain Overlay District is presumed to be in violation until such time as the documentation is provided.

"Water dependent" means a structure for commerce or industry which cannot exist in any other location and is dependent on the water by reason of the intrinsic nature of its operations.

"Water surface elevation" means the height, in relation to the national geodetic vertical datum (NGVD) of 1929, the North American vertical datum of 1988 (NAVD88), or other datum, of floodwaters of various magnitudes and frequencies in the floodplains of coastal or riverine areas.

"Watercourse" means a natural or artificial channel in which a flow of water occurs either continually or intermittently in an identified floodplain.

(Ord. No. 2023-03, § 2(Exh. B), 8-21-2023)

A.

Applicable Lands. The Floodplain Overlay District applies to special flood hazard areas within the city limits.

B.

Basis For Establishing Special Flood Hazard Areas.

1.

The special flood hazard areas are identified by the Federal Insurance Administrator in a scientific and engineering report entitled "The Flood Insurance Study for Yamhill County, Oregon and Incorporated Areas," dated March 2, 2010, with accompanying flood insurance rale maps. The study and maps are incorporated in the Floodplain Overlay District by this reference and are on file at the City of Sheridan city hall.

2.

When base flood elevation data has not been provided on the FIRM (A Zone) in accordance with Section 16.280.030, B, Basis for Establishing The Special Flood Hazard Areas, the local Floodplain Administrator shall obtain, review, and reasonably utilize any Base Flood Elevation and floodway data available from a Federal, State or other source, to administer the provisions of the Floodplain Overlay District.

C.

Compliance, Coordination and Penalties For Noncompliance.

1.

Compliance. All development within special Hood hazard areas is subject to the Floodplain Overlay District and all other applicable regulations.

2.

Coordination With Oregon Specialty Codes. Pursuant to the requirement established in ORS 455 that the City administers and enforces the State of Oregon Specialty Codes, the City of Sheridan does hereby acknowledge that the Oregon Specialty Codes contain certain provisions that apply to the design and construction of buildings and structures located in special flood hazard areas. Therefore, the FPO is intended to be administered and enforced in conjunction with the Oregon Specialty Codes.

3.

Penalties For Noncompliance. No structure or land shall hereafter be constructed, located, extended, converted, or altered without compliance with the Floodplain Overlay District and all other applicable regulations. For violations of the provisions of the Floodplain Overlay District or failure to comply with any of its requirements, including violations of conditions and safeguards established in connection with conditions, the city may withhold any further permits and may withhold or withdraw city utility services until correction is made. Notwithstanding any such action taken by the city, any person, firm or corporation who violates, disobeys, omits, neglects, or refuses to comply with any of the provisions of the Floodplain Overlay District, or who resists the enforcement of such provisions, shall be subject to civil penalties specified under the Sheridan Municipal Code. Each day that a violation is permitted to exist shall constitute a separate offense. Penalties shall be in accordance with Section 16.105.010, Violations - Penalties. Nothing contained herein shall prevent the City of Sheridan from taking such other lawful action as is necessary to prevent or remedy any violation.

D.

Abrogation, Greater Restrictions and Severability.

1.

Abrogation and Greater Restrictions. The Floodplain Overlay District is not intended to repeal, abrogate, or impair any existing easements, covenants, or deed restrictions. However, where the Floodplain Overlay District or other Sheridan Development Code regulation, State building code regulation, easement, covenant, or deed restriction conflicts or overlaps, whichever imposes the more stringent restrictions shall prevail.

2.

Severability. The Floodplain Overlay District is hereby declared to be severable. Where any Section, clause, sentence, or phrase of the Floodplain Overlay District is held to be invalid or unconstitutional by any court of competent jurisdiction, said holding shall in no way effect the validity of the remaining portions of the Floodplain Overlay District.

E.

Interpretation. In the interpretation and application of the Floodplain Overlay District, all provisions shall be:

1.

Considered as minimum requirements.

2.

Liberally construed in favor of the governing body.

3.

Deemed neither to limit nor repeal any other powers granted under State statutes and rules including the State building codes.

F.

Designation of Local Floodplain Administrator. The city manager, or designee, is hereby appointed as the local Floodplain Administrator to administer and implement the Floodplain Overlay District by granting or denying floodplain development permit applications in accordance with the Floodplain Overlay District provisions.

G.

Duties and Responsibilities of The Local Floodplain Administrator. Duties of the local Floodplain Administrator, shall include, but are not limited to:

1.

Review all development permits to determine whether the permit requirements and provisions of the Floodplain Overlay District are met.

a.

Determine whether the proposed development qualifies as a Substantial Improvement as defined in Section 16.280.020, Definitions.

b.

Determine whether the proposed development is a watercourse alteration. Where the proposal is determined by be a watercourse alteration, ensure compliance with Section 16.280.060, A, Alteration of Watercourses.

c.

Determine whether the proposed development includes the placement of fill or is an excavation.

2.

Review all development permits to ensure all other required local, State, and Federal permits have been obtained and approved.

3.

Review all development permits to determine if the proposed development is in the floodway. If located in the floodway, ensure the floodway provisions in Section 16.280.070, L, Floodways, are met.

4.

Interpret the provisions of the Floodplain Overlay District consistent with Section 16.280.030, E, Interpretation.

5.

Review all development permits to determine whether the proposed development is in an area where Base Flood Elevation (BFE) data is available either through the Flood Insurance Study (FIS) or from another authoritative source. if BFE data is not available, ensure compliance with the provisions of Section 16.280,060, G, Use of Other Base Flood Data.

6.

Interpretation of Flood Insurance Rate Map (FIRM) Boundaries.

When base flood elevation data has not been provided, the Floodplain Administrator shall have the authority to interpret the location of the boundary of the special flood hazard area, for example, where there appears to be a conflict between a mapped boundary and actual field conditions. A party may appeal the interpretation decision provided a letter appealing the decision is submitted within fifteen (15) calendar days of the date the interpretation decision was mailed to the parties. The appeal shall be reviewed and decided consistent with the standards of Section 60.6 of the rules and regulations of the National Flood Insurance Program (44 CFR 59-76).

7.

Information to be Obtained and Maintained. The following information shall be obtained and maintained, and shall be made available for public inspection as needed.

a.

Obtain, record and maintain the elevation, in relation to mean sea level, of the lowest floor, including basements, and attendant utilities of new or substantially improved structures where Base Flood Elevation data is provided through the Flood Insurance Study (FIS), Flood Insurance Rate Map (FIRM), or is obtained in accordance with Section 16.280.060, G, Use of Other Base Flood Data.

b.

For new or substantially improved floodproofed structures where base flood elevation data is provided through the flood insurance study, flood insurance rate map, or as required in Section 16.280.060, G, Use of Other Base Flood Data:

i.

Verify and record the actual elevation as furnished by the developer (in relation to mean sea level), and

ii.

Maintain any floodproofing certifications required by the Floodplain Overlay District;

c.

Obtain, record and maintain the elevation, in relation to mean sea level, of the natural grade of the building site for a structure prior to the start of construction and the placement of any fill, and ensure the requirements of Sections 16.280.030, G, 2, Other Local, State and Federal Permits, and 16.280.070, L, Floodways, are met.

Upon placement of a structure's lowest floor, including a basement, and prior to further vertical construction, obtain documentation prepared by a professional land surveyor certifying the elevation, in relation to mean sea level, of the lowest floor, including a basement.

d.

Where base flood elevation data are used, obtain a "Finished Construction" Elevation Certificate (as-built certification), in relation to mean sea level, of the lowest floor, including a basement, prepared by a professional land surveyor prior to the final inspection.

e.

Maintain elevation certificates submitted to the City of Sheridan.

f.

Obtain, record, and maintain the elevation, in relation to mean sea level, to which the structure and attendant utilities were floodproofed for new or substantially improved floodproofed structures where allowed under the Floodplain Overlay District and where base flood elevation data is provided through the flood insurance study, flood insurance rate maps, or is obtained in accordance with Section 16.280.060, G, Use of Other Base Flood Data.

g.

Maintain floodproofing certificates required under the Floodplain Overlay District.

h.

Record and maintain floodplain variance application approvals and denials.

i.

Obtain and maintain floodplain development permit decisions approving or denying development in the Floodway, including hydrologic and hydraulic analyses as required in Section 16.280.060, L, Floodway.

j.

Record and maintain substantial improvement and substantial damage decisions, including the justification for the decisions as required in Section 16.280.030, G, 11, Duties and Responsibilities of the Floodplain Administrator.

k.

Maintain records pertaining to floodplain variances and the insurance notification associated with approved floodplain variances.

l.

Maintain for public inspection all records pertaining to the Floodplain Overlay District.

8.

Watercourse alterations.

a.

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. The floodplain development permit applicant shall submit evidence of such notification to the Federal Insurance Administration as a letter of map revision (LOMR) including:

i.

A proposed maintenance plan to assure the flood carrying capacity within the altered or relocated portion of the watercourse is maintained: or

ii.

Certification by a registered professional engineer that the project has been designed to retain its flood carrying capacity without periodic maintenance.

b.

The floodplain development permit applicant shall submit a conditional letter of map revision (CLOMR) when required under section 16.280.030, G, 9, Requirement To Submit New Technical Data, or 16.280.060, A, Watercourse Alterations.

9.

Requirement to Submit New Technical Data.

a.

A community's base flood elevations may increase or decrease resulting from physical changes affecting flooding conditions. As soon as practicable, but not later than six (6) months after the date such information becomes available, a community shall notify the Federal Insurance Administrator of the changes by submitting technical or scientific data in accordance with Section 44 of the Code of Federal Regulations (CFR), Subsection 65.3. The community may require the applicant to submit such data and review fees required for compliance with this Section through the applicable FEMA Letter of Map Change (LOMC) process.

b.

The floodplain administrator shall require a conditional letter of map revision (CLOMR) prior to the issuance of a floodplain development permit for:

i.

Proposed floodway encroachments that increase the base flood elevation; and

ii.

Proposed development outside the floodway which increases the base flood elevation by more than one foot in areas where FEMA has provided base flood elevations.

c.

An applicant shall notify FEMA within six (6) months of project completion when an applicant has obtained a conditional letter of map revision (CLOMR) from FEMA, or when development altered a watercourse, modified floodplain boundaries, or modified base flood elevations. The notification to FEMA shall be provided as a letter of map revision (LOMR).

d.

The applicant shall be responsible for preparing the technical data to support the CLOMR/LOMR applications and paying any processing or application fees associated with the CLOMR/LOMR.

e.

The floodplain administrator shall be under no obligation to sign the community acknowledgement form, which is part of the CLOMR/LOMR application, until the applicant demonstrates the project will meet, or has met, the requirements of the Floodplain Overlay District and applicable State and Federal laws.

The floodplain administrator, or designee, shall be under no obligation to sign the community acknowledgement form, which is part of the CLOMR/LOMR application, until the applicant demonstrates the project will meet, or has met, the requirements of the Floodplain Overlay District and all applicable State and Federal laws.

10.

Community Boundary Alterations.

The floodplain administrator, or designee, shall notify the Federal Insurance Administrator in writing whenever the City of Sheridan city limits have been modified by annexation or the city has otherwise assumed authority or no longer has authority to adopt and enforce floodplain management regulations for a particular area, to ensure that all flood hazard boundary maps (FHBM) and flood insurance rate maps (FIRM) accurately represent the community's boundaries. Include within such notification a copy of a map of the community suitable for reproduction, clearly delineating the new corporate limits or new area for which the community has assumed or relinquished floodplain management regulatory authority.

11.

Substantial Improvement and Substantial Damage Determinations.

a.

Conduct a substantial improvement (SI) determination for development which meets the definition of Substantial Improvement as set forth in Section 16.280.020, Definitions, and maintain the records in accordance with Section 16.280.030, G, 7, j.

b.

Conduct a substantial damage (SD) determination when a structure is damaged consistent with the definition of substantial damage as set forth in section 16.280.020, Definitions, and maintain the records in accordance with section 16.280.030, G, 7,j.

12.

Floodplain Variance Notification.

An applicant to whom a variance is granted shall be given written notice that the issuance of a variance to construct a structure below the base flood elevation will result in increased premium rates for flood insurance and that such construction below the base flood elevation increases risks to life and property. Such notification and a record of the variance actions, including justification for their issuance shall be maintained in accordance with section 16.280.030, G, 7, k.

H.

Establishment of floodplain development permit (FDP).

1.

Except as set forth in section 16.280.040 for exempt uses, a floodplain development permit approval shall be obtained before construction or development, including a manufactured home placement, begins within any area horizontally within the special flood hazard area.

2.

A floodplain development permit application shall be reviewed and decided by the floodplain administrator, as a type I-A action in accordance with section 16,504 or, as appropriate, a type I-B action in accordance with section 16.506.

3.

A floodplain development permit application shall be submitted in accordance with section 16.548.030, Application Submittal Requirements.

4.

In riverine flood zones, the application shall show or include:

a.

The proposed elevation, in relation to mean sea level, of the lowest floor, including basement, and attendant utilities of new and substantially improved structures, in accordance with the requirements of Section 16.280.030, G, 7, Information to be Obtained and Maintained.

b.

The proposed elevation in relation to mean sea level to which any non- residential structure will be floodproofed.

c.

A certification by a registered professional engineer or architect licensed in the State of Oregon showing the floodproofing methods proposed for any non-residential structure meet the floodproofing criteria for non- residential structures in Section 16.280.070, C, 4, Non-residential Construction.

d.

A description of the extent to which any watercourse will be altered or relocated.

e.

Base flood elevation data for subdivision proposals or other development when required in accordance with Section 16.280.060, F, Subdivisions and Other Proposed Developments.

f.

Substantial improvement calculation for any improvement, addition, reconstruction, renovation, or rehabilitation of an existing structure.

g.

The amount and location of proposed fill or excavation.

I.

Pursuant to the requirement established in ORS 455 where the city administers and enforces the State of Oregon Specialty codes, or contracts with another agency to administer and enforce the State of Oregon Specialty codes, the City of Sheridan does hereby acknowledge the Oregon Specialty Codes contain certain provisions that apply to the design and construction of buildings and structures located in special flood hazard areas. Therefore, the Floodplain Overlay District is intended to be administered and enforced in conjunction with the Oregon Specialty Codes.

(Ord. No. 2023-03, § 2(Exh. B), 8-21-2023)

Within the Floodplain Overlay District, no uses, structures, vehicles, premises or land shall be used or established, except as provided in the applicable underlying zone and the provisions of the Floodplain Overlay District. The following uses are exempt from the regulations of this overlay zone:

A.

Signs, markers, aids, etc., placed by a public agency to serve the public;

B.

Driveways, and open space use areas where no alteration of topography will occur;

C.

Routine maintenance and repairs to existing structures provided the maintenance and repairs do not increase the footprint of the structure, and do not constitute "substantial improvement" as defined in Section 16.280.020;

D.

Replacement of utility facilities necessary to serve established and permitted uses within special flood hazard, such as telephone poles. This exemption does not apply to the replacement of buildings and substations, or to electrical, heating, ventilation, plumbing and air-conditioning systems, or other similar types of service equipment in special flood hazard areas.

(Ord. No. 2023-03, § 2(Exh. B), 8-21-2023)

Except for accessory structures as set forth in Section 16.280.070, D, if otherwise allowed as a permitted use or a conditional use in the underlying zone, dwellings, a manufactured home on a lot, a manufactured home in a manufactured home park, structures and the placement of fill to elevate a structure, may be allowed subject to an approved flood plain development permit showing the following requirements are met or will be met as construction occurs:

A.

The structure or fill is not located within a floodway;

B.

The required elevation to which the lowest floor of the structure must be elevated can be determined from the flood insurance study, flood insurance rate map, or consistent with Section 16.280.030G.5, Use of Other Base Flood Data;

C.

The structures will be located on natural grade or compacted fill;

D.

The lowest floor will be elevated to at least one foot above the base flood elevation and the requirements in Section 16.280.070, Flood Protection Standards, will be met;

E.

Any construction and substantial improvements below the base flood elevation shall meet the requirements of Section 16.280.070, Flood Protection Standards;

F.

The building permit specifies the required elevation of the lowest floor, any anchoring requirements, any foundation venting requirements and provides the certification required for floodproofing under Section l6.280.070C.Ec., Flood Protection Standards, prior to occupancy;

G.

A certificate signed by a licensed surveyor or civil engineer certifying that the lowest floor, including basement, is at least one foot above the base flood elevation, is submitted to the city manager, or designee, prior to use of the structure;

1.

No alteration of topography beyond the perimeter of the structure is proposed.

(Ord. No. 2023-03, § 2(Exh. B), 8-21-2023)

In special flood hazard areas, the following requirements apply.

A.

Alteration of Watercourses.

The flood carrying capacity within the altered or relocated portion of the watercourse shall be maintained. Maintenance shall be provided within the altered or relocated portion of said watercourse to ensure the flood carrying capacity is not diminished. The alteration shall comply with Sections 16.280.030, G, 8, Watercourse Alterations, and 16.280.030, G, 9, Requirement to Submit New Technical Data.

B.

Anchoring.

1.

New construction and substantial improvements shall be anchored to prevent floatation, collapse, or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy.

2.

All manufactured homes shall be anchored in accordance with Section 16.280.070, C, 3, Manufactured Dwellings.

C.

Construction Materials and Methods.

1.

New construction and substantial improvements below the level that is one-foot above the base flood elevation shall be constructed with materials resistant to flood damage. Utility equipment shall be at least one foot above the base flood elevation.

2.

New construction and substantial improvements shall be constructed using methods and practices that minimize flood damage.

D.

Utilities And Equipment.

1.

Water Supply, Sanitary Sewer, and On-Site Waste Disposal Systems.

a.

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 discharge 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 standards.

2.

Electrical, Mechanical, Plumbing, And Other Equipment

a.

Electrical, heating, ventilating, air-conditioning, plumbing, duct systems, and other equipment and service facilities for new construction shall be elevated at least one foot above the base flood elevation.

b.

Electrical, heating, ventilating, air-conditioning, plumbing, duct systems, and other equipment and service facilities, if replaced as part of a substantial improvement shall be elevated at least one foot above the base flood elevation.

E.

Tanks.

1.

Underground tanks shall be anchored to prevent flotation, collapse and lateral movement under conditions of the Base Flood.

2.

Above-ground tanks shall be installed at least one-foot above the base flood elevation and shall be anchored to prevent flotation, collapse, and lateral movement. Above-ground tanks installed more than one-foot above the base flood elevation are exempt from the anchoring requirement.

F.

Subdivisions and Other Developments.

1.

New subdivision proposals and other new development proposals, including manufactured dwelling parks and manufactured dwelling subdivisions, greater than fifty (50) lots or five (5) acres, whichever is less, shall include base flood elevation data.

2.

New subdivision proposals and other new development proposals, including manufactured dwelling parks and manufactured dwelling subdivisions, shall:

a.

Be consistent with the need to minimize flood damage.

b.

Install public utilities and facilities including, but not limited to, sewer, gas, electrical, telecommunications, and water systems to minimize or eliminate flood damage.

c.

Provide adequate drainage to reduce exposure to flood hazards.

G.

Use of Other Base Flood Data.

1.

Base flood elevations (BFE) shall be determined for development proposals that are five (5) or more acres, or are fifty (50) lots or more, whichever is less, in any A Zone that does not have an established BFE.

2.

Development proposals located within a riverine unnumbered A Zone shall be constructed to be reasonably safe from flooding. As determined by the local floodplain administrator, information including, but not limited to, the use of historical data, high water marks, FEMA provided base level engineering data, and photographs of past flooding, may be used to achieve the "reasonably safe" criterion in an A Zone that does not have an established BFE.

3.

When base flood elevation data has not been provided on the FIRM (A Zone) in accordance with Section 16.280.030, B, Basis for Establishing The Special Flood Hazard Areas, the local floodplain administrator may obtain, review, and reasonably utilize any base flood elevation and floodway data available from a Federal, State or other source, to administer the provisions of the Floodplain Overlay District.

4.

Within a riverine unnumbered A Zone, structures shall be elevated a minimum of 2-feet above the highest adjacent grade.

H.

Structures Located in Multiple or Partial Flood Zones.

In coordination with the State of Oregon Specialty Codes:

I.

When a structure is in multiple flood zones on the community's flood insurance rate maps (FIRM), the provisions for the more restrictive flood zone shall apply.

J.

When a structure is partially located in a special flood hazard area, the entire structure shall meet the requirements for new construction and substantial improvements.

(Ord. No. 2023-03, § 2(Exh. B), 8-21-2023)

In special flood hazards areas the following requirements apply:

A.

Flood Openings (Flood Vents).

New construction and substantial improvements with fully enclosed areas below the lowest floor, excluding basements, and enclosed areas below the base flood elevation, including crawl spaces, shall install flood openings subject to the following requirements.

1.

Flood openings (flood vents) shall be designed and constructed to automatically equalize hydrostatic flood forces on walls by allowing for the entry and exit of floodwaters;

2.

Be used solely for parking, storage, or building access;

3.

Be certified by a registered professional engineer or architect to meet or exceed the following standards:

a.

A minimum of two (2) openings;

b.

The total net area of non-engineered openings shall be not less than one (1) square inch for each square foot of enclosed area, where the enclosed area is measured on the exterior of the enclosure walls;

c.

The bottom of all openings shall be no higher than 1-foot above grade.

d.

Openings may be equipped with screens, louvers, valves, or other coverings or devices provided they allow the automatic flow of floodwater into and out of the enclosed areas, and they are accounted for in the determination of the net open area.

e.

When applicable, comply with the additional higher standards for flood openings in the State of Oregon Residential Specialty Code, Section R322.2.2.

B.

Garages.

1.

Attached garages may be constructed with the garage floor slab below the base flood elevation (BFE) in riverine flood zones, provided the following requirements are met:

a.

When located partially or wholly in a Floodway, the proposed garage must comply with section 16.280.070, L, Floodways;

b.

The floor is at or above grade on not less than one side;

c.

The garage is used solely for parking, building access, and/or storage;

d.

The garage is constructed with flood openings in compliance with Section 16.280.070, A, to equalize hydrostatic flood forces on exterior walls by allowing for the automatic entry and exit of floodwater.

e.

The portions of the garage constructed below the BFE are constructed with materials resistant to flood damage;

f.

The garage is constructed in compliance with the standards in Section 16.280.060; and

g.

The garage is constructed with electrical and other service facilities located and installed to prevent water from entering or accumulating within the components during conditions of the base flood.

2.

Detached garages must be constructed in compliance with the standards for appurtenant structures in Section 16.280.070, D, Appurtenant (Accessory) Structures, or non-residential development in Section 16.280.070, C, 4, Non- Residential Development, depending on the square footage of the garage.

C.

Riverine (Non-Coastal) Special Flood Hazard Areas with Base Flood Elevations.

In addition to the standards in section 16.280.060 the following standards shall apply in riverine (non-coastal) special flood hazard areas with Base Flood Elevations (BFE): Zones A1-A30, AH, and AE.

1.

Before a Regulatory Floodway is Designated.

In areas where a regulatory floodway has not been designated, no new construction, substantial improvement, or other development, including fill, shall be permitted within Zones A1-30 and AE on the City of Sheridan's flood insurance rate maps (FIRM), unless it is demonstrated that the cumulative effect of the proposed development, when combined with all other existing and anticipated development, will not increase the water surface elevation of the base flood more than 1-foot at any point within the community.

2.

Residential Development.

a.

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

b.

Enclosed areas below the lowest floor shall comply with the flood opening requirements in Section 16.280.070, A.

3.

Manufactured Dwellings.

a.

The bottom of the longitudinal chassis frame beam shall be at or above the base flood elevation.

b.

New or substantially improved manufactured dwellings supported on solid foundation walls, shall comply with section 16.280.070, A, Flood Openings.

c.

New or substantially improved manufactured dwellings shall be anchored to prevent floatation, collapse and lateral movement during the base flood. Anchoring methods may include, but are not limited to the use of over-the-top, or frame ties to ground, anchors (see FEMA's "Manufactured Home Installation in Flood Hazard Area" guidebook for additional techniques).

d.

Electrical crossover connections shall be a minimum of one-foot above the base flood elevation.

4.

Non-residential development.

a.

New construction and substantial improvement of any commercial, industrial, or other non-residential structure shall:

i.

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, be floodproofed so the structure is watertight with walls substantially impermeable to the passage of water up to a level that is one foot above the base flood elevation;

ii.

Have structural components capable of resisting hydrostatic and hydrodynamic loads and the effects of buoyancy.

iii.

Be certified by a registered professional engineer that the design and methods of construction are in accordance with accepted standards of practice for meeting the provisions of section 16.280.070, C, 4, based on their development and/or review of the structural design, specifications and plans. The certificate shall include the elevation, in relation to mean sea level, to which the structure is floodproofed. The certification shall be submitted with the floodplain development permit application.

b.

Non-residential structures that are elevated, not floodproofed, shall comply with the standards for enclosed areas below the lowest floor in section 16.280.070, A, Flood Openings.

c.

Applicants floodproofing non-residential buildings shall be notified by the city that flood insurance premiums will be based on rates that are one-foot below the floodproofed level, for example, a building floodproofed to the base flood elevation will be rated as one-foot below that elevation.

d.

Applicants for a flood plain development permit that proposes floodproofing a nonresidential building shall submit a comprehensive maintenance plan for the entire structure, including but not limited to:

i.

The exterior envelope of the structure;

ii.

All penetrations to the exterior of the structure;

iii.

All shields, gates, barriers, or components designed to provide floodproofing protection to the structure;

iv.

All seals and gaskets for shields, gates, barriers, or components; and

v.

The location of all shields, gates, barriers, and components, as el associated hardware and any materials or specialized tools necessary to seal the structure.

e.

Applicants for a flood plain development permit that proposes floodproofing a non-residential building shall submit an emergency action plan (EAP) for the installation and sealing of the structure prior to a flooding event that clearly identifies what triggers the EAP and who is responsible for enacting the EAP.

D.

Appurtenant (Accessory) Structures. Relief from elevation or floodproofing requirements for residential and non-residential appurtenant structures in riverine (non-coastal) flood zones may be granted for appurtenant structures that meet the following:

1.

It is used only for the parking of vehicles, access and/or the storage of items unlikely to be damaged by flood waters (a low damage potential. An appurtenant (accessory) structure shall not be used for human habitation or to operate equipment or to place appliances, including but not limited to freezers, refrigerators, washers, dryers, pool tables, couches and stuffed chairs;

2.

It is anchored consistent with section 16.280.060, B, Anchoring, to prevent floatation, collapse or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy, during conditions of the base flood;

3.

The portions of the appurtenant structure located below the level that is 1-foot above the base flood elevation must be constructed using flood resistant materials;

4.

The appurtenant structure must be designed and constructed to equalize hydrostatic flood forces on exterior walls and comply with the flood opening requirement in section 16.280.070, A, Flood Openings;

5.

It is constructed with the electrical, mechanical and other service equipment located and installed at least one (1) foot above the base flood elevation;

6.

It is not used to store toxic material, oil or gasoline, or any priority persistent pollutant identified by the Oregon Department of Environmental Quality, unless confined in a tank installed in compliance with Section 16.280.060, E, Tanks;

7.

It is located and constructed to have low damage potential.;

8.

In compliance with the State of Oregon Specialty Codes, appurtenant structures on properties zoned residential (R-1, R-2, R-3 and UT) are limited to 1-story structures less than two hundred (200) square feet, or four hundred (400) square feet if the property is greater than 2-acres and the proposed appurtenant structure will be located a minimum of twenty (20) feet from all property lines. Appurtenant structures on properties zoned non-residential (commercial, industrial, public facilities) are limited to one hundred twenty (120) square feet.

9.

Appurtenant structures located partially or wholly within the floodway must comply with the requirements for development within the floodway in section 16.280.070, L.

E.

Reserved.

F.

Reserved.

G.

Reserved.

H.

Reserved.

I.

Reserved.

J.

Reserved.

K.

Review of Building Permits. Where elevation data is not available either through the flood insurance study, flood insurance rate map, or from another authoritative source in accordance with 16.280.060, G, Use of Other Base Flood Data, flood plain development permit applications related to a building permit shall be reviewed through the type I-B process to ensure the proposed construction will be reasonably safe from flooding. The test of reasonableness shall be based on available data, including but not limited to historical data, high water marks, and photographs of past flooding. The lowest floor shall be at least two (2) feet above grade in these zones.

L.

Floodways. Located within the special flood hazard areas established in Section 16.280.030 B., Basis for Special Flood Hazard Areas, are areas designated as floodways. The floodway is an extremely hazardous area due to the velocity of floodwaters which carry debris and potential projectiles, and causes erosion. The following provisions apply to development in the floodway:

1.

Encroachments, including but not limited to fill, new construction, substantial improvements and other development within the regulatory floodway are prohibited, unless:

a.

Certification by a registered professional civil engineer is provided demonstrating through hydrologic and hydraulic analyses performed in accordance with FEMA standards and standard engineering practices the proposed encroachments shall not result in an increase in flood levels during the occurrence of the base flood discharge; or

b.

An encroachment may be permitted within the regulatory floodway that would result in an increase in the base flood elevation, provided a conditional letter of map revision (CLOMR) is submitted and approved by the Federal Insurance Administrator, and the requirements for such revision as established under Volume 44, Code of Federal Regulations, Section 65.12 are fulfilled.

2.

Where the requirements of Section 16.280.070, L, I, are met, new construction, substantial improvements, and other development shall comply with all other applicable provisions of Sections 16.280.060, Provisions For Flood Hazard Reduction, and 16.280.070, Standards For Riverine Flood Zones.

3.

For structures, the area below the lowest floor shall remain open and unenclosed to allow the unrestricted flow of floodwaters beneath the structure.

4.

A manufactured home on an individual lot or parcel, or in a manufactured home park, is prohibited in the floodway.

5.

Projects for stream habitat restoration may be permitted in the floodway provided the project:

a.

Is for the purpose of fish enhancement;

b.

Does not involve the placement of any structures, as defined in section 18.280.020, within the floodway;

c.

Has a feasibility analysis completed documenting the fish enhancement will be achieved through the proposed project;

d.

Has a maintenance plan in place to ensure the stream carrying capacity is not impacted by the fish enhancement project;

e.

Has approval by the National Marine Fisheries Service, the Sate of Oregon department of Fish and Wildlife, or the equivalent Federal or State agency; and

f.

Has evidence to support that no existing structures will be negatively impacted by the proposed activity.

M.

Recreational Vehicles.

1.

A recreational vehicle in the special flood hazard area (100-year floodplain) shall comply with the Sheridan Municipal Code requirements for recreational vehicles and the following, whichever are more stringent:

a.

Be on the site for fewer than one hundred eighty (180) consecutive days;

b.

Be fully licensed and ready for highway use;

c.

Be on its wheels or jacking system;

d.

Have no permanently attached additions;

e.

Be attached to the site only by quick disconnect type utilities and security devices; or

2.

Meet the requirements of Section 16.280.070, C, 3, Manufactured Homes.

N.

Below Grade Crawl Space.

1.

A below-grade crawlspace is allowed subject to the following standards as found in FEMA technical bulletin 11-01, "Crawlspace Construction for Buildings Located in Special Flood Flazard Areas." For structures with a below grade crawlspace contact an insurance agent for insurance information.

a.

The building shall 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 Section 16.280.070, A, Flood Openings. Because of hydrodynamic loads, crawlspace construction is not allowed in areas with flood velocities greater than five (5) feet per second unless the design is reviewed by a qualified design professional, such as a registered professional engineer. Other types of foundations are recommended for these areas.

b.

The crawl space is an enclosed area below the Base Flood Elevation (BFE) and, as such, shall have openings that equalize hydrostatic pressures by allowing the automatic entry and exit of floodwaters. The bottom of each flood vent opening shall be no more than one foot above the lowest adjacent exterior grade.

c.

Portions of the building below the level that is one-foot above the BFE shall be constructed with materials resistant to flood damage, including but not limited to the foundation walls of the crawl space used to elevate the building, posts, joists, insulation, or other materials that extend below the level that is one-foot above the BFE. The recommended construction practice is to elevate the bottom of joists and all insulation above BFE.

d.

Any building utility systems within the crawlspace shall be at least one-foot above the base flood elevation.

e.

The interior grade of a crawlspace below the base flood elevation shall not be more than two (2) feet below the lowest adjacent exterior grade.

f.

The height of the below-grade crawlspace, measured from the interior grade of the crawlspace to the top of the crawlspace foundation wall shall not exceed four (4) 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.

g.

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

h.

The velocity of floodwaters at the site should not exceed five (5) feet per second for any crawlspace. For velocities in excess of five (5) feet per second, other foundation types should be used.

2.

For more detailed information refer to FEMA technical bulletin 11-01, including the diagrams that illustrate the two-foot and four-foot rules, and note the state building code requirements require the lowest floor to be at least one-foot above the base flood elevation for residential structures.

O.

Standards For Shallow Flooding Areas.

1.

Shallow flooding areas appear on flood insurance rate maps as AO zones with depth designations, or as AH zones with base flood elevations. For AO zones the base flood depths range from one to three (3) feet above ground where a clearly defined channel does not exist, or where the path of flooding is unpredictable and where velocity flow may be evident. Such flooding is usually characterized as sheet flow.

2.

For both AO and AH zones, adequate drainage paths are required around structures on slopes to guide floodwaters around and away from proposed structures.

3.

Standards For AH Zones. Development within AH Zones must comply with the standards in Sections 16.280.060, Provisions For Flood Hazard Reduction and 16.280.070, O, Standards For Shallow Flooding Areas.

4.

Standards For AO Zones. In AO zones, the following provisions apply in addition to the requirements in Sections 16.280.060, Provisions For Flood Hazard Reduction, and 16.280.070, 0, 1 and 2:

a.

New construction and substantial improvement of residential structures and manufactured dwellings within AO zones shall have the lowest floor, including basement, elevated above the highest grade adjacent to the building, at minimum to or above the depth number specified on the flood insurance rate maps or one foot above the base flood elevation (at least two (2) feet if no depth number is specified). For manufactured dwellings the lowest floor is the bottom of the longitudinal chassis frame beam.

b.

New construction and substantial improvements of non-residential structures within AO zones shall either:

i.

Have the lowest floor (including basement) elevated above the highest adjacent grade of the building site, at minimum to or above the depth number specified on the flood insurance rate maps or one (1) foot above the base flood elevation (at least two (2) feet if no depth number is specified); or

ii.

Together with attendant utility and sanitary facilities, be completely floodproofed to or above the depth number specified on the Flood Insurance Rate Map or one foot above the base flood elevation or a minimum of two (2) feet above the highest adjacent grade if no depth number is specified, so that any space below that level is watertight with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and effects of buoyancy. If this method is used, compliance shall be certified by a registered professional engineer or architect as stated in Section 16.280.070, C, 4, a, iii.

c.

Recreational vehicles placed on sites within AO Zones on the flood insurance rate maps (FIRM) shall either:

i.

Be on the site for fewer than one hundred eighty (180) consecutive days, and

ii.

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

iii.

Meet the elevation requirements of Section 16.280.070, C, Rand the anchoring and other requirements for manufactured dwellings of Section 16.280.070, C, 3.

d.

In AO zones, new and substantially improved appurtenant structures must comply with the standards in Section 16.280.070, D, Appurtenant Structures.

e.

In AO zones, enclosed areas beneath elevated structures shall comply with the requirements in Section 16.280.070, A, Flood Openings.

(Ord. No. 2023-03, § 2(Exh. B), 8-21-2023)

Where elevation data is generalized, such as the unnumbered A zones on the flood insurance rate map, a flood plain development permit processed as a type I-B action shall include a review and determination that the proposed construction will be reasonably safe from flooding and meet the flood protection standards. In determining whether the proposed floodplain development is reasonably safe, historical data, high water marks, photographs of past flooding, or data (e.g. an engineering study or soil and landscape analysis) may be submitted by qualified professionals that demonstrate the site is not in a floodplain. In such cases, a letter of map amendment may be required by the local floodplain administrator, or designee.

(Ord. No. 2023-03, § 2(Exh. B), 8-21-2023)

A.

The issuance of a variance is for floodplain management purposes only. Flood insurance premium rates are determined by Federal statute according to actuarial risk and will not be modified by the granting of a variance.

B.

Generally, variances may be issued for new construction and substantial improvements to be erected on a lot of one-half acre or less contiguous to and surrounded by lots with existing structures constructed below the base flood elevation, in conformance with the provisions of Sections 16.280.090, B, 3 and 5, and 16.280.030,1, 12, Variance Notification. As the lot size increases greater than one-half acre, the technical justification required for issuing a variance increases.

1.

Floodplain Variance Approval Criteria. An application for a floodplain variance may be approved when the following approval criteria are shown by the application materials to be met:

a.

The variance is the minimum necessary, considering the flood hazard, to afford relief;

b.

A showing of good and sufficient cause;

c.

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

d.

A determination that granting the 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 laws or ordinances; and

e.

In accordance with Section 16.280.070, L, l, a, Floodways, a variance for a structure or other development partially or wholly within the floodway will not result in any increase in flood levels during the base flood discharge.

2.

Functionally Dependent Uses. Variances may be approved for new construction, substantial improvements and other development necessary for a functionally dependent use provided the criteria of Section 16.280.090, B, 1, a—e, are met, and the structure or other development is protected by methods that minimize flood damage during the base flood and create no additional threats to public safety.

C.

Variance Notification.

An applicant to whom a variance is granted shall be given written notice in accordance with Section 16.280.030, G, 12, Floodplain Variance Notification. The notification and a record of all variance actions, including justification for variance decisions, shall be maintained in accordance with Section 16.280.030, G, 7, k, Information to be Obtained and Maintained.

D.

Variances may be issued for the reconstruction, rehabilitation, or restoration of structures listed on the national register of historic places or the statewide inventory of historic properties, in accordance with Section 16.576, Major Variance, and Section 16.578, Minor Variance, without regard to the procedures set forth in Sections 16.280.090, Floodplain Variances.

(Ord. No. 2023-03, § 2(Exh. B), 8-21-2023)

A.

Warning. The degree of flood protection required by the Floodplain Overlay District is considered reasonable for regulatory purposes and is based on scientific and engineering considerations. Larger floods can and will occur on occasion. Flood heights may be increased by man-made or natural causes. The Floodplain Overlay District does not imply that land outside the special flood hazard areas or uses permitted within such areas will be free from flooding or flood damages.

B.

Disclaimer of Liability. The Floodplain Overlay District shall not create liability on the part of the city, any officer or employee thereof, or the Federal Insurance Administrator for any flood damages that result from reliance on the Floodplain Overlay District or any administrative decision lawfully made thereunder.

(Ord. No. 2023-03, § 2(Exh. B), 8-21-2023)