1. Statutory Authorization.
   1. The Legislature of the State of Utah has in Utah Code Unannotated 10-3-701 delegated the responsibility to local governmental units to adopt regulations designed to promote the public health, safety, and general welfare of its citizenry. Therefore, the Municipal Council of the Town of Brighton does ordain as follows:
   2. The Town of Brighton elects to comply with the requirements of the National Flood Insurance Act of 1968 (P.L. 90-488, as amended). The National Flood Insurance Program (NFIP) is a voluntary program administered by the Federal Emergency Management Agency (FEMA), a component of the U.S. Department of Homeland Security, and the Town of Brighton 's community officials have elected to join the program, participate, and enforce this Flood Damage Prevention Ordinance and the requirements and regulations of the NFIP. The NFIP, established in the aforesaid act, provides that areas of the Town of Brighton having a special flood hazard be identified by FEMA, and that floodplain management measures be applied in such flood hazard areas. Furthermore, the Town of Brighton may elect to administer the Flood Damage Prevention Ordinance to areas not identified as Special Flood Hazard Areas (SFHAs) by FEMA on the community's effective Flood Insurance Rate Map (FIRM), if the community has documentation to support that there is an inherent risk of flooding in such areas.
2. Findings of Fact.
   1. The flood hazard areas of the Town of Brighton are subject to periodic inundation which results in loss of life and property, health and safety hazards, disruption of commerce and governmental services, and extraordinary public expenditures for flood protection and relief, all of which adversely affect the public health, safety, and general welfare.
   2. These flood losses are created by the cumulative effect of obstructions in floodplains which cause an increase in flood heights and velocities, and by the occupancy of flood hazards areas by uses vulnerable to floods and hazardous to other lands because they are inadequately elevated, floodproofed or otherwise protected from flood damage.
   3. These potential flood losses are caused by:
      1. The cumulative effect of obstructions in floodplains that are known to cause increases in flood heights and velocities;
      2. The occupancy of flood hazard areas by structures vulnerable to floods because they are inadequately elevated or otherwise unprotected from flood damages; and
      3. Uses deemed unsuitable for floodplain areas or that do not account for the increased flood risk.

1. It is the purpose of this Chapter to promote the public health, safety and general welfare of the community and to minimize public and private losses due to flood conditions in specific areas by provisions designed to:
   1. Protect human life and health;
   2. Minimize 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, telephone and sewer lines, streets and bridges located in floodplains;
   6. Help maintain a stable tax base by providing for the sound use and development of flood-prone areas in such a manner as to minimize future flood blight areas;
   7. Ensure that potential buyers are notified that property is in a flood area and can make their decisions based on full information; and
   8. Ensure that those who occupy the areas of special flood hazards assume responsibility for their actions.

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

1. Restricting or prohibiting land uses that are dangerous to health, safety, or property in times of flooding, or cause excessive increases in flood heights or velocities;
2. Requiring that land uses vulnerable to floods, including facilities that serve such uses, be protected against flood damage at the time of initial construction;
3. Controlling the alteration of natural floodplains, stream channels, and natural protective barriers, which are involved in the accommodation of flood waters;
4. Controlling filling, grading, dredging and other developments that may increase flood damage; and
5. Preventing or regulating the construction of flood barriers that will unnaturally divert floodwaters or may increase flood hazards to other lands.

1. Lands to Which This Chapter Applies. This chapter shall apply to all areas of special flood hazards within the jurisdiction of the Town of Brighton.
2. Basis for Establishing the Areas of Special Flood Hazard. The areas of special flood hazard identified by the Federal Emergency Management Agency in a scientific and engineering report entitled, "The Flood Insurance Study for Salt Lake County and Incorporated Communities," dated November 19, 2021, with accompanying flood insurance rate maps (FIRMs), and any revisions thereto are hereby automatically adopted by reference and declared to be a part of this chapter.
3. Establishment of Development Permit. A Floodplain Development Permit shall be required to ensure conformance with the provisions of this Chapter.
4. Compliance. No structure or land shall hereafter be located, altered, or have its use changed without full compliance with the terms of this Chapter and other applicable regulations.
5. Abrogation and Greater Restrictions. This Chapter is not intended to repeal, abrogate, or impair any existing easements, covenants, or deed restrictions. However, where this Chapter and another ordinance, easement, covenant, or deed restriction conflict or overlap, whichever imposes the more stringent restrictions shall prevail.
6. Interpretation. In the interpretation and application of this Chapter, all provisions shall be:
   1. Considered as minimum requirements;
   2. Liberally construed in favor of the governing body; and
   3. Deemed neither to limit nor repeal any other powers granted under State statutes.
7. Warning and Disclaimer of Liability.
   1. 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.
   2. This chapter does not imply that land outside the areas of special flood hazards or uses permitted within such areas will be free from flooding or flood damages. This chapter shall not create liability on the part of the Town of Brighton, any officer or employee thereof, or the Federal Emergency Management Agency, for any flood damages that result from reliance on this chapter, or any administrative decision lawfully made thereunder.

1. Floodplain Administrator Appointed. The Director of Planning and Development Services is hereby appointed the Floodplain Administrator to administer and implement the provisions of this Chapter and other appropriate sections of 44 CFR (National Flood Insurance Program Regulations) pertaining to floodplain management.
2. Duties and Responsibilities of the Floodplain Administrator. Duties and responsibilities of the Floodplain Administrator shall include, but not be limited to, the following:
   1. Review all applications to determine if the proposed development is located in the floodway. If located in the floodway, assure that the encroachment provisions of Section 19.56.100 (F) are met,
   2. Maintain and hold open for public inspection all records pertaining to the provisions of this Chapter.
   3. Obtain and record the actual elevation provided by the developer (in relation to mean sea level) of the lowest floor, including basement, of all new or substantially improved structures except those located in zone A where base flood elevation data was not available nor required by this chapter,
   4. For all new or substantially improved floodproofed structures except those located in zone A where base flood elevation data was not available nor required by this chapter:
      1. Verify and record the actual elevation provided by the developer (in relation to mean sea level), and
      2. Maintain the floodproofing certifications required in Subsection (A)(6) of Section 19.56.080,
   5. Review permit application to determine whether proposed building site, including the placement of manufactured homes, will be reasonably safe from flooding.
   6. Review, approve or deny all applications for development permits required by adoption of this Chapter.
   7. Review permits for proposed development to assure that all necessary permits have been obtained from those Federal, State or local governmental agencies (including Section 404 of the Federal Water Pollution Control Act Amendments of 1972, 33 U.S.C. 1334) from which prior approval is required.
   8. Where interpretation is 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 Floodplain Administrator shall make the necessary interpretation.
   9. Verify that notification has been made to cities adjacent to the watercourse and to the State Division of Comprehensive Emergency Management, prior to any alteration or relocation of a watercourse, and evidence of such notification has been submitted to the Federal Emergency Management Agency.
   10. Verify that maintenance is provided for within the altered or relocated portion of such watercourse so the flood-carrying capacity is not diminished,
   11. Assure that the flood carrying capacity within the altered or relocated portion of any watercourse is maintained.
   12. When base flood elevation data has not been provided in accordance with Article 3, Section B, the Floodplain Administrator shall obtain, review and reasonably utilize any base flood elevation data and floodway data available from a Federal, State or other source, in order to administer the provisions of Article 5.
   13. When a regulatory floodway has not been designated, the Floodplain Administrator must require that no new construction, substantial improvements, or other development (including fill) shall be permitted within Zones A1-30 and AE on the community's 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 one foot at any point within the community.
3. Under the provisions of 44 CFR Chapter 1, Section 65.12, of the National Flood Insurance Program regulations, a community may approve certain development in Zones A1-30, AE, AH, on the community's FIRM which increases the water surface elevation of the base flood by more than one foot, provided that the community first applies for a conditional FIRM revision through FEMA (Conditional Letter of Map Revision).

The floodplain hazard regulations of this chapter shall be supplemental to, and not in lieu of, the applicable zoning provisions of the zone in which the land is located, and/or general provisions under Title 19 of this code, as amended. Property located within such areas of special flood hazard shall be developed only in conformance with the provisions set forth herein. In cases of conflict between such zone classifications and the floodplain hazard regulations, the most restrictive provisions shall govern. Permitted and conditional uses permitted in the areas of special flood hazard shall be developed only in conformance with the provisions set forth herein. All uses involving development, as defined in this chapter, shall further meet the supplemental conditions and standards set forth in this chapter.

A conditional use permit, if required by this title, shall be obtained prior to special flood hazard area approval under Section 19.74.080. Prior to issuance of a conditional use permit, the planning commission shall insure that requirements of this chapter are met.

1. Application. Application for a Floodplain Development Permit shall be presented to the Floodplain Administrator on forms furnished by him/her and may include, but not be limited to, plans in duplicate drawn to scale showing the location, dimensions, and elevation of proposed landscape alterations, existing and proposed structures, including the placement of manufactured homes, and the location of the foregoing in relation to areas of special flood hazard. Additionally, the following submittals and information are required:
   1. Plans drawn to scale shoring the location, dimensions, and elevations of proposed landscape alterations.
   2. Plans drawn to scale showing the location, dimensions, and elevation of existing and proposed structures, including the placement of manufactured homes.
   3. Location of the foregoing in relation to SFHA’s.
   4. Elevation, in relation to mean sea level, of the lowest floor (including basement and crawlspace) of all new and substantially improved structures.
   5. Elevation, in relation to mean sea level, to which any nonresidential structure (if applicable) shall be floodproofed.
   6. A certificate from a registered professional engineer that the nonresidential floodproofed structure (if applicable) shall meet the floodproofing criteria of this chapter and the NFIP Regulations.
   7. Description of the extent to which any watercourse or natural drainage will be altered or relocated as a result of proposed development.
   8. All other information that may reasonable be required by the Floodplain Administrator.
   9. Reasonable fees in accordance with the adopted fee schedule.
   10. The Town of Brighton shall become the owner of all Floodplain Development Permits and shall maintain a record of all such information in accordance with this chapter and the NFIP Regulations.
2. Approval or Denial. Approval or denial of a Floodplain Development Permit by the Floodplain Administrator shall be based on all of the provisions of this Chapter and the following relevant factors:
   1. The danger to life and property due to flooding or erosion damage;
   2. The susceptibility of the proposed facility and its contents to flood damage and the effect of such damage on the individual owner;
   3. The danger that materials may be swept onto other lands to the injury of others;
   4. The compatibility of the proposed use with existing and anticipated development;
   5. The safety of access to the property in times of flood for ordinary and emergency vehicles;
   6. The costs of providing governmental services during and after flood conditions including maintenance and repair of streets and bridges, and public utilities and facilities such as sewer, gas, electrical and water systems;
   7. 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;
   8. The necessity to the facility of a waterfront location, where applicable;
   9. The availability of alternative locations, not subject to flooding or erosion damage, for the proposed use; and
   10. The relationship of the proposed use to the comprehensive plan for that area.

1. The Land Use Hearing Officer shall hear and decide all appeals and requests for variances from the requirements of this chapter, as provided in Chapter 19.20 of this Title, as amended. The following conditions shall apply, in addition to the provisions of Chapter 19.20:
   1. Generally, variances may be issued 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 one foot above the base level, providing the Land Use Hearing Officer has considered all technical evaluations, all relevant factors, and standards specified in other sections of this chapter, providing the following items have been considered:
      1. The danger that materials may be swept onto other land to the injury of others;
      2. The danger to life and property due to flooding or erosion damage;
      3. The susceptibility of the proposed facility and its contents to flood damage, and the effect of such damage on the individual owner;
      4. The importance of the services provided by the proposed facility to the community;
      5. The necessity to the facility of a waterfront location, where applicable;
      6. The availability of alternative locations for the proposed use, which are not subject to flooding or erosion damage;
      7. The compatibility of the proposed use with the existing and anticipated development;
      8. The relationship of the proposed use to the comprehensive plan and floodplain management program for that area;
      9. The safety of access to the property in times of flood for ordinary and emergency vehicles;
      10. The expected heights, velocity, duration, rate of rise, and sediment transport of the floodwaters and the effects of wave action, if applicable, expected at the site; and
      11. 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. Variances may be issued for the reconstruction, rehabilitation or restoration of structures listed on the National Register of Historic Places or the State Inventory of Historic Places, without regard to the procedures set forth in the remainder of this section.
   3. Variances shall not be issued within any designated floodway if any increase in flood levels during the base flood discharge would result.
   4. The Floodplain Administrator shall maintain in perpetuity a record of all variance actions, including justification for their issuance, and shall report variances to FEMA and the State Coordinating Agency upon issuing a variance.
2. Prerequisites for Granting a Variance.
   1. Variances shall only be issued upon a determination that the variance is the minimum necessary, considering the flood hazard, to afford relief.
   2. Variances shall only be issued upon:
      1. A showing of good and sufficient cause;
      2. A determination that failure to grant the variance would result in exceptional and undue hardship to the applicant; and
      3. 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.
   3. Any applicant to whom a variance is granted shall be given written notice that the structure will be permitted to be built with a lowest floor elevation below one foot above the base flood elevation and that the cost of flood insurance will be commensurate with the increased flood risk resulting from the reduced lowest floor elevation.
3. The Land Use Hearing Officer shall maintain the record of all appeal actions and report any variances to the Federal Emergency Management Agency upon request.

1. General Standards. In all areas of special flood hazards, the following standards are required for all new construction and substantial improvements:
   1. All new construction and substantial improvements shall be designed (or modified) and adequately anchored to prevent flotation, collapse, or lateral movement of the structure and capable of resisting the hydrostatic and hydrodynamic loads, including the effects of buoyancy.
   2. All new construction or substantial improvements shall be constructed by methods and practices that minimize flood damage;
   3. All new construction or substantial improvements shall be constructed with materials resistant to flood damage;
   4. All new construction or substantial improvements shall be constructed with electrical, heating, ventilation, plumbing, and air conditioning equipment and other service facilities that are designed and/or located so as to prevent water from entering or accumulating within the components during conditions of flooding.
   5. All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of flood waters into the system;
   6. New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of flood waters into the system and discharge from the systems into flood waters; and
   7. On-site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding.
2. Substantial Improvement and Substantial Damage Determination. For applications for building permits to improve buildings and structures within a special flood hazard area, including alterations, movement, enlargement, replacement, repair, change of occupancy, additions, rehabilitations, renovations, and any other improvement of or work on such buildings and structures, the Floodplain Administrator, shall:
   1. Estimate the market value of the building or structure only (not of land) before the start of construction of the proposed work. If the applicant disagrees with the estimated market value, the applicant may obtain an appraisal of the market value prepared by a qualified independent appraiser. In the case of repair, the market value of the building or structure shall be the market value before the damage occurred and before any repairs are made.
   2. Compare the cost to perform the improvement, the cost to repair a damaged building to its pre-damaged condition, or the combined costs of improvements and repairs, if applicable, to the market value of the building or structure.
   3. Determine and document whether the proposed work constitutes substantial improvement or repair of substantial damage; the determination requires evaluation of previous permits issued for improvements and repairs.
   4. Utilize FEMA’s Substantial Improvement/Substantial Desk Reference when making any determination on Substantial Improvement and/or Substantial Damage.
   5. The substantial improvement regulations apply to all of the work that is proposed as the improvement, even if multiple permits are issued. Therefore, the determination of the cost of the improvement should consider all costs of all phases of the work before issuance of the first permit.
   6. Notify the applicant that if it is determined that the work constitutes substantial improvement or repair of substantial damage, compliance with the flood regulations of this chapter is required.
3. Specific Standards. In all areas of special flood hazards where base flood elevation data has been provided as set forth in this chapter, the following standards are required:
   1. Residential Construction. New construction and substantial improvement of any residential structure shall have the lowest floor (including basement) elevated to 1 foot or more above the base flood elevation. A registered professional engineer, or land surveyor shall submit a certification to the Floodplain Administrator that the standard of this chapter are satisfied.
   2. Nonresidential Construction. New construction and substantial improvement of any commercial, or other nonresidential structure shall either have the lowest floor (including basement) elevated to 1 foot or more above the base flood elevation or together with attendant utility and sanitary facilities, be designed so that below the base flood level the structure 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. A registered professional engineer shall develop and/or review structural design, specifications, and plans for the construction, and shall certify that the design and methods of construction are in accordance with accepted standards of practice as outlined in this subsection. A record of such certification which includes the specific elevation (in relation to mean sea level) to which such structures are floodproofed shall be maintained by the Floodplain Administrator.
   3. Enclosures. New construction and substantial improvements, with fully enclosed areas below the lowest floor that are usable solely for parking of vehicles, building access or storage in an area other than a basement and which are subject to flooding 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 meet or exceed the following minimum criteria:
      1. A minimum of two openings having a total net area of not less than one (1) 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 (1’) above grade.
      3. Openings may be equipped with screens, louvers, valves, or other coverings or devices provided that they permit the automatic entry and exit of floodwaters.
   4. Enclosures below the BFE. Enclosures below the BFE may only be used for building access, vehicle parking, and storage. Certification and documentation from a professional, licensed engineer is required if the structure’s lowest floor is built below the BFE. Applicant shall enter into a maintenance and nonconversion agreement with the Town of Brighton that it will maintain the improvements outlined in this paragraph and not modify or convert them to uses other than approved uses.
   5. Crawlspaces. New construction and substantial improvements built on an at grade crawlspace or sub-grade (below grade) crawlspace may be permitted if the development is designed and meets or exceeds the standards found in FEMA’s Technical Bulletins 1, 2, and 11, which include but are not limited to the following:
      1. The structure must be affixed to a permanent foundation, 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. Because of hydrodynamic loads, crawlspace construction is not allowed in areas with flood velocities greater than five feet (5’) per second unless the design is reviewed by a qualified design professional, such as a registered professional engineer.
      2. The crawlspace is an enclosed area below the BFE and, as such, must have flood 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 (1’) above the LAG.
      3. The crawlspace enclosure must have proper flood openings that allow equalization of hydrostatic pressure by allowing automatic entry and exit of floodwaters. To achieve this, a minimum of one square inch of flood opening is required per one square foot of the enclosed area subject to flooding.
      4. 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, piers, or other materials that extend below the BFE. Ductwork must either be placed above the BFE or sealed from floodwaters.
      5. Any building utility systems within the crawlspace must be elevated above the BFE or designed so that floodwaters cannot enter or accumulate within the system components during flood conditions.
      6. The interior grade of a crawlspace below the BFE must not be more than two feet (2’) below the LAG.
      7. The height of the below-grade crawlspace, measured from the lowest interior grade of the crawlspace floor to the bottom of the floor joist of the next higher floor cannot exceed four feet (4’) at any point.
      8. 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.
      9. Note. Buildings with below grade crawlspaces will have higher flood insurance premiums than buildings that have preferred crawlspace construction, with interior elevation at or above the LAG.
   6. Manufactured Homes.
      1. All manufactured homes to be placed within Zone A on a community's FHBM or FIRM shall be installed using methods and practices which minimize flood damage. For the purposes of this requirement, manufactured homes must be elevated and anchored to resist flotation, collapse, or lateral movement. Methods of anchoring may include, but are not limited to, use of over-the-top or frame ties to ground anchors. This requirement is in addition to applicable State and local anchoring requirements for resisting wind forces.
      2. Manufactured homes that are placed or substantially improved within Zones A1-30, AH, and AE on the community's FIRM on sites outside of a manufactured home park or subdivision; in a new manufactured home park or subdivision; in an expansion to an existing manufactured home park or subdivision; or in an existing manufactured home park or subdivision on which a manufactured home has incurred "substantial damage" as a result of a flood, be elevated on a permanent foundation such that the lowest floor of the manufactured home is elevated to one foot (1’) or more above the base flood elevation and be securely anchored to an adequately anchored foundation system to resist flotation, collapse, and lateral movement.
      3. In the A1-30, AH, AO and AE Zones, manufactured homes placed or substantially improved in an existing manufactured home park shall be elevated so that the lowest floor is one foot (1’) or more above the base flood elevation; or the manufactured home chassis is supported by reinforced piers or other foundation elements of at least equivalent strength that are no less than 36 inches in height above grade and be securely anchored to an adequately anchored foundation system to resist flotation, collapse, and lateral movement.
   7. Recreational Vehicles. Recreational vehicles placed on sites within Zones A1-30, AH, and AE on the community's FIRM either:
      1. Be on the site for fewer than one-hundred and eighty (180) consecutive days and be fully licensed and ready for highway use;
      2. A recreational vehicle is ready for highway use if it is 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 permit requirements and the elevation and anchoring requirements for "manufactured homes" in this section.
4. Standards for Subdivision Proposals.
   1. All subdivision proposals including the placement of manufactured home parks and subdivisions shall have adequate drainage provided to reduce exposure to flood hazards.
   2. All proposals for the development of subdivisions including the placement of manufactured home parks and subdivisions shall meet Floodplain Development Permit and other requirements of this chapter.
   3. Base flood elevation data shall be generated for subdivision proposals and other proposed development that is greater than fifty (50) lots or five (5) acres, including the placement of manufactured home parks and subdivisions.
   4. All subdivision proposals, including the placement of manufactured home parks and subdivisions shall, have public utilities and facilities such as sewer, gas, electrical and water systems located and constructed to minimize or eliminate flood damage.
5. Standards for Areas of Shallow Flooding (AO/AH Zones). Located within the areas of special flood hazard established by this chapter, are areas designated as shallow flooding. These areas have special flood hazards associated with base flood depths of 1 to 3 feet where a clearly defined channel does not exist and where the path of flooding is unpredictable and where velocity flow may be evident. Such flooding is characterized by ponding or sheet flow; therefore, the following provisions apply:
   1. All new construction and substantial improvements of residential structures have the lowest floor (including basement) elevated one foot (1’) or more above the highest adjacent grade at least as high as the depth number specified in feet on the community's FIRM (at least two feet if no depth number is specified).
   2. All new construction and substantial improvements of non-residential structures:
      1. Have the lowest floor (including basement) elevated one foot (1’) or more above the highest adjacent grade at least as high as the depth number specified in feet on the community's FIRM (at least two feet (2’) if no depth number is specified), or;
      2. Together with attendant utility and sanitary facilities be designed so that below one foot (1’) above the base flood level the structure is watertight with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads of effects of buoyancy.
   3. A registered professional engineer shall submit a certification to the Floodplain Administrator that the standards of this subsection are satisfied.
   4. Require within Zones AH or AO adequate drainage paths around structures on slopes, to guide flood waters around and away from proposed structures.
6. Floodways. Located within areas of special flood hazard established in Section 19.56.040 are areas designated as "floodways." Since the floodway is an extremely hazardous area due to the velocity of floodwaters which carry debris, potential projectiles, and erosion potential, the following provisions apply:
   1. Encroachments, including fill, new construction, substantial improvements, placement of manufactured homes, and other developments, are prohibited unless it has been demonstrated through hydrologic and hydraulic analyses performed in accordance with standard engineering practice that the proposed encroachment would not result in any increase in flood levels within the community during the occurrence of the base flood discharge.
   2. If subsection A of this section is satisfied, all new construction and substantial improvements and placement of manufactured homes shall comply with all applicable flood-hazard reduction provisions of Sections 19.56.100 through 19.56.180.
   3. Under the provisions of 44 CFR Chapter 1, Section 65.12, of the National Flood Insurance Regulations, a community may permit encroachments within the adopted regulatory floodway that would result in an increase in base flood elevations, provided that the community first applies for a conditional FIRM and floodway revision through FEMA.

1. The following definitions shall apply to terms used in this Chapter only. Unless specifically defined below, words or phrases used in this Chapter shall be interpreted to give them the meaning they have in common usage and to give this Chapter its most reasonable application.
   1. “100-Year Flood” means a flood having a recurrence interval that has a 1-percent chance of being equaled or exceeded during any given year (1-percent-annual-chance flood). The terms “100- hundred-year flood” and “1-percent-annual-chance flood” are synonymous. The term does not imply that the flood will necessarily happen once every 100 hundred years. Mandatory flood insurance requirements may apply.
   2. “100-Year Floodplain” means the area of land susceptible to being inundated due to the occurrence of a 1-percent-annual-chance flood.
   3. “500-Year Flood” means a flood having a recurrence interval that has a 0.2-percent chance of being equaled or exceeded during any given year (0.2-percent-annual-chance flood). The term does not imply that the flood will necessarily happen once every 500 years and mandatory flood insurance requirement generally does not apply.
   4. “500-Year Floodplain” means the area of land susceptible to being inundated due to the occurrence of a 0.2-percent-annual-chance flood.
   5. “Accessory Structure” means a structure that is on the same parcel of property as a principal structure. Its use is incidental to the use of the principal structure. The ownership of the accessory structure is the same owner as of the principal structure. An accessory structure is a nonresidential structure of low value that is used solely for the parking of vehicles and storage of tools, materials, or equipment. No human habitation is allowed within an accessory structure.
   6. “Addition” means any improvement that expands the enclosed footprint or increases the square footage of an existing structure. This includes lateral additions added to the side, front, or rear of a structure; vertical additions added on top of a structure; and enclosures added underneath a structure.
   7. “Alluvial Fan Flooding” means flooding occurring on the surface of an alluvial fan or similar landform which originates at the apex and is characterized by high-velocity flows; active processes of erosion, sediment transport, and deposition; and unpredictable flow paths.
   8. “APEX” means a point on an alluvial fan or similar landform below which the flow path of the major stream that formed the fan becomes unpredictable and alluvial fan flooding can occur.
   9. “Appurtenant Structure”—see Accessory Structure.
   10. “Area of Future-Conditions Flood Hazard” means the land area that would be inundated by the 1-percent-annual-chance (100-year) flood, based on future-conditions hydrology.
   11. “Area of Shallow Flooding” means a designated AO, AH, or VO zone on a community's Flood Insurance Rate Map (FIRM) with a one percent chance or greater annual chance of flooding to an average depth of one to three feet (1’-3’) 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.
   12. “Area of Special Flood-Related Erosion Hazard” means the land within a community that is most likely to be subject to severe flood-related erosion losses. The area may be designated as Zone E on the Flood Hazard Boundary Map (FHBM). After the detailed evaluation of the special flood-related erosion hazard area, in preparation for publication of the FIRM, Zone E may be further refined.
   13. “Area of Special Flood Hazard” means the lands in the floodplain within a community subject to a one percent or greater chance of flooding in any given year. The area may be designated as Zone A on the Flood Hazard Boundary Map (FHBM). After detailed ratemaking has been completed in preparation for publication of the FIRM, Zone A usually is refined into Zones A, AE, AH, AO, A1-99, VO, V1-30, VE or V
   14. “Base Flood” means the flood having a 1-percent chance of being equaled or exceeded in any given year.
   15. “Base Flood Elevation (BFE)” means the water surface elevation of the 1-percent-annual-chance flood event. It is the height in relation to mean sea level expected to be reached by the waters of the base flood at pertinent points in the floodplains of coastal and riverine areas. It is also the elevation shown on the FIRM and found in the accompanying Flood Insurance Study (FIS) for Zones A, AE, AH, A1-A30, AR, V1-V30, or VE that indicates the water surface elevation resulting from the flood that has a 1-percent chance of equaling or exceeding that level in any given year.
   16. “Basement” means any area of the building having its floor subgrade (below ground level) on all sides. A walkout basement that does not require a step up to grade is not considered a basement.
   17. “Best Available Data” means existing flood hazard information adopted by a community and reflected on an effective FIRM, FBFM, and/or within an FIS report; or draft or preliminary flood hazard information supplied by FEMA or from another source. Other sources may include, but are not limited to, state, other federal agencies, or local studies, the more restrictive of which would be reasonably used by the community. {If Higher Standard Option elected refer to ARTICLE III, SECTION B.1 USE OF BEST AVAILABLE DATA}
   18. “Breakaway Wall” means a wall that is not part of the structural support of the building and is intended through its design and construction to collapse under specific lateral loading forces, without causing damage to the elevated portion of the building or supporting foundation system. Any walls below the lowest floor in a building in a V or VE Zone should give way under wind and water loads without causing collapse, displacement, or other damage to the elevated portion of the building of the supporting pilings or columns. Breakaway walls apply only to V or VE Zones.
   19. “Building” see Structure.
   20. “Channelization” means the artificial creation, enlargement, realignment, or alteration of a stream channel’s slope, shape, or alignment. Streambank restoration may be deemed as channelization.
   21. “Code of Federal Regulations (CFR)” means the codification of the general and permanent rules published in the Federal Register by the executive departments and agencies of the Federal Government.
   22. “Conditional Letter of Map Revision (CLOMR)” means FEMA's comment on a proposed project that would, upon construction, affect the hydrologic and/or hydraulic characteristics of a flooding source and thus result in the modification of the existing regulatory floodway, the effective BFEs, and/or the SFHA. The letter does not revise an effective map; it indicates whether the project, if built as proposed, would be recognized by FEMA.
   23. “Conditional Letter of Map Revision Based on Fill (CLOMR-F)” means FEMA's comment on a proposed structure or property. The letter does not revise an effective map; it indicates whether the project, if built as proposed, would be removed from the floodplain.
   24. “Crawlspace” means an under-floor space that has its interior floor area (finished or not) no more than four feet (4’) from the bottom floor joist the next higher floor elevation, designed with proper openings that equalize hydrostatic pressures of flood water, and is not used for habitation.
   25. “Critical Facility” means a facility or building where even a slight chance of flooding is too great a threat. Typical critical facilities include hospitals, fire stations, police stations, schools, storage of critical records, assisted living and similar facilities.
   26. “Critical Feature” means an integral and readily identifiable part of a flood protection system, without which the flood protection provided by the entire system would be compromised.
   27. “Deed Restriction” means a clause in a deed that limits the future use of the property in some respect. Deed restrictions may impose a vast variety of limitations and conditions. For example, they may limit the density of buildings, dictate the types of structures that can be erected, or prevent buildings from being used for specific purposes or from being used at all.
   28. “Detached Garage” means a building that is used solely for storage of materials or vehicle parking for up to four housing occupants. If a detached garage is designed or used for habitation or conducting business, or has multiple stories, then the building is not considered a detached garage under the NFIP.
   29. “Development” means any human-made change to improved or unimproved real estate, including but not limited to buildings or other structures, mining, dredging, filling, grading, paving, demolition, excavation or drilling operations, or storage either temporary or permanent of equipment or materials.
   30. “Elevated Building” means a non-basement building (i) built, in the case of a building in Zones A1-30, AE, A, A99, AO, AH, B, C, X, and D, to have the top of the elevated floor, or in the case of a building in Zones V1-30, VE, or V, to have the bottom of the lowest horizontal structure member of the elevated floor elevated above the ground level by means of pilings, columns (posts and piers), or shear walls parallel to the floor of the water and (ii) adequately anchored so as not to impair the structural integrity of the building during a flood of up to the magnitude of the base flood. In the case of Zones A1-30, AE, A, A99, AO, AH, B, C, X, and D, "elevated building" also includes a building elevated by means of fill or solid foundation perimeter walls with openings sufficient to facilitate the unimpeded movement of flood waters. In the case of Zones V1-30, VE, or V, "elevated building" also includes a building otherwise meeting the definition of "elevated building," even though the lower area is enclosed by means of breakaway walls if the breakaway walls met the standards of Section 60.3(e)(5) of the National Flood Insurance Program regulations.
   31. “Enclosure” means an enclosed walled-in area below the lowest floor of an elevated building. Enclosures below the BFE may only be used for building access, vehicle parking, and storage.
   32. “Erosion” means the process of the gradual wearing away of land masses by wind, water, or other natural agents.
   33. “Existing Construction” means structures for which the “start of construction” commenced before the effective date of the FIRM or before January 1, 1975, for FIRMs effective before that date. It may also be referred to as Existing Structures.
   34. “Existing Manufactured Home Park or Subdivision” means a manufactured home park or subdivision for which the construction of facilities for servicing the 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 completed before the effective date of the floodplain management regulations adopted by the community.
   35. “Existing Structures”—see Existing Construction.
   36. “Expansion to an Existing Manufactured Home Park or Subdivision” means the preparation of additional sites by the construction of facilities for servicing the lots on which the manufacturing homes are to be affixed (including the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads).
   37. “FEMA” means the Federal Emergency Management Agency.
   38. “FHBM” means Flood Hazard Boundary Map.
   39. “Fill” means the placement of materials, such as dirt, sand, or rock to elevate a structure, property, or portion of a property above the natural elevation of the site, regardless of where the material was obtained from. The common practice of removing unsuitable material and replacing with engineered material is not considered fill if the elevations are returned to the existing conditions. Any fill placed or used prior to the area being mapped as a flood hazard area is not deemed as fill.
   40. “Flood or Flooding” means:
       1. A general and temporary condition of partial or complete inundation of normally dry land areas from:
       2. The overflow of inland or tidal waters.
       3. The unusual and rapid accumulation or runoff of surface waters from any source.
       4. Mudslides (i.e., mudflows) that are proximately caused by flooding as defined in this Chapter 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.
       5. The collapse or subsidence of land along the shore of a lake or other body of water as a result of erosion or undermining caused by waves or currents of water exceeding anticipated cyclical levels or suddenly caused by an unusually high water level in a natural body of water, accompanied by a severe storm, or by an unanticipated force of nature, such as flash flood or an abnormal tidal surge, or by some similarly unusual and unforeseeable event which results in flooding as defined in this Chapter.
   41. “Flood Insurance Manual” means the document FEMA produces twice a year and is used to write flood insurance policies underwritten by the NFIP. The document contains definitions, policy rates, coverage and limitations, application and insurance policy forms.
   42. “Flood Insurance Rate Map (FIRM)” means an official map of a community, on which the Federal Emergency Management Agency has delineated both the areas of special flood hazards and the risk premium zones applicable to the community. A FIRM that has been made available digitally is called a Digital Flood Insurance Rate Map (DFIRM).
   43. “Flood Insurance Study (FIS) or 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.
   44. “Floodplain Development Permit” means a community issued permit or document that is used for any development that occurs within an SFHA identified by FEMA or the community. It is used to address the proposed development to ensure compliance with the community’s ordinance.
   45. “Floodplain or Flood-Prone Area” means any land area susceptible to being inundated by water from any source whether or not identified by FEMA (see definition of Flooding).
   46. “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, mitigation plans, and floodplain management regulations.
   47. “Floodplain Management Regulations” means zoning ordinances, subdivision regulations, building codes, health regulations, special purpose ordinances (such as a floodplain ordinance, grading ordinance and erosion control ordinance) and other applications of police power. The term describes such state or local regulations, in any combination thereof, which provide standards for flood damage prevention and reduction.
   48. “Flood Opening” means an opening in the wall of an enclosed structure that allows floodwaters to automatically enter and exit the enclosure. Refer to FEMA Technical Bulletin 1.
   49. “Flood Protection System” means those physical structural works for which funds have been authorized, appropriated, and expended and which have been constructed specifically to modify flooding in order to reduce the extent of the area within a community subject to an SFHA and to reduce the depths of associated flooding. Such a system typically includes hurricane tidal barriers, dams, reservoirs, levees or dikes. These specialized, flood modifying works are those constructed in conformance with sound engineering standards. FEMA only accredits levees, both private and public, that have been certified by a professional engineer or firm in which the certification shows that the levee have met and continue to meet the minimum regulatory standards cited in Title 44, Chapter 1, Section 65.10 of the Code of Federal Regulations (44 CFR 65.10).
   50. “Floodproofing” means any combination of structural and non-structural additions, changes, or adjustments to structures that reduce or eliminate flood damage to real estate or improved real property, water and sanitary facilities, structures and their contents. Floodproofing can either be accomplished in the form of dry floodproofing in which the structure is watertight below the levels that need flood protection, or wet floodproofing in permanent or contingent measures applied to a structure that prevent or provide resistance to damage from flooding, while allowing floodwaters to enter the structure or area.
   51. “Floodway”—see Regulatory Floodway.
   52. “Floodway encroachment lines” mean the lines marking the limits of floodways on federal, state, and local flood plain maps.
   53. “Freeboard” means a factor of safety usually expressed in feet above a flood level for purposes of flood plain management. “Freeboard” tends to compensate for the many unknown factors that could contribute to flood heights greater than the height calculated for a selected size flood and floodway conditions, such as wave action, bridge openings, and the hydrological effect of urbanization of the watershed.
   54. “Functionally Dependent Use” means a development that cannot perform its intended purpose unless it is located or carried out in close proximity to water. The term includes docking facilities, port facilities that are necessary for the loading and unloading of cargo or passengers, and ship building and repair facilities. It does not include long-term storage or related manufacturing facilities.
   55. “Highest Adjacent Grade (HAG)” means the highest natural elevation of the ground surface prior to construction next to the proposed walls of a structure. In AO Zones, the highest adjacent grade is utilized by comparing the lowest floor elevation to that of the highest adjacent grade and the depth of the AO Zone.
   56. “Historic Structure” means any structure that is:
       1. 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;
       2. Certified or preliminarily determined by the Secretary of the Interior as contributing to the historical significance of a registered historic district or a district preliminarily determined by the Secretary to qualify as a registered historic district;
       3. Individually listed on a state inventory of historic places in states with historic reservation programs that have been approved by the Secretary of the Interior; or
       4. Individually listed on a local inventory of historic places in communities with historic preservation programs that have been certified either:
       5. By an approved state program as determined by the Secretary of the Interior, or
       6. Directly by the Secretary of the Interior in states without approved programs.
   57. “Letter of Map Amendment (LOMA)” means an official amendment, by letter, to an effective FIRM. A LOMA establishes a property’s location in relation to the SFHA. It is usually issued because a property or structure has been inadvertently mapped as being in the floodplain, when it is actually on natural high ground above the BFE.
   58. “Letter of Map Revision (LOMR)” means FEMA's modification or revision to an entire or portion of the effective FIRM, or Flood Boundary and Floodway Map, 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 BFEs, or the SFHA.
   59. “Letter of Map Revision Based on Fill (LOMR-F)” means FEMA’s amendment, by letter, to an effective FIRM where fill was brought in or used to elevate a property, portion of property or structure above the BFE.
   60. “Levee” means a man-made structure usually an earthen embankment, designed and constructed in accordance with sound engineering practices to contain, control, or divert the flow of water so as to provide protection from temporary flooding.
   61. “Levee System” means a flood protection system that consists of a levee, or levees, and associated structures, such as closure and drainage devices, which are constructed and operated in accordance with sound engineering practices.
   62. “Lowest Adjacent Grade (LAG)” means the lowest natural elevation of the ground surface prior to construction next to the proposed walls of a structure. For an existing structure, it means the lowest point where the structure and ground touch, including but not limited to attached garages, decks, stairs, and basement windows.
   63. “Lowest floor” means the lowest floor of the lowest enclosed area (including basement). An unfinished or flood-resistant enclosure, usable solely for parking of vehicles, building access or storage, in an area other than a basement area, is not considered a building's lowest floor, provided that such enclosure is not built so as to render the structure in violation of the applicable nonelevation design requirements of this Title.
   64. “Manufactured home” means a structure, transportable in one or more sections, which is built on a permanent chassis and is designed for use with or without a permanent foundation when connected to the required utilities. For floodplain management purposes, the term "manufactured home" also includes park trailers, travel trailers, and other similar vehicles placed on a site for greater than one hundred eighty consecutive days. For insurance purposes the term "manufactured home" does not include park trailers, travel trailers, and other similar vehicles.
   65. “Manufactured Home Park or Subdivision” means a parcel (or contiguous parcels) of land divided into two or more manufactured home lots for rent or sale.
   66. “Map” means the FHBM or the FIRM for a community issued by FEMA.
   67. “Mean Sea Level” means, for purposes of the NFIP, the National Geodetic Vertical Datum (NGVD) of 1929, North American Vertical Datum (NAVD) of 1988, or other datum, to which BFEs shown on a community's FIRM are referenced.
   68. “Mixed Use Structures” means structures with both a business and a residential component, but where the area used for business is less than 50 percent of the total floor area of the structure.
   69. “New Construction” means structures for which the start of construction commenced on or after the effective date of a floodplain management regulation adopted by a community and includes any subsequent improvements to such structures. For the purposes of determining insurance rates, structures for which the “start of construction” commenced on or after the effective date of an initial FIRM or after December 31, 1974, whichever is later, and includes any subsequent improvements to such structures. For floodplain management purposes, "new construction" means structures for which the "start of construction" commenced on or after the effective date of a floodplain management regulation adopted by a community and includes any subsequent improvements to such structures.
   70. “New Manufactured Home Park or Subdivision” means a manufactured home park or subdivision for which the construction of facilities for servicing the 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 completed on or after the effective date of floodplain management regulations adopted by a community.
   71. “No-Rise Certifications” means formal certifications signed and stamped by a professional engineer licensed to practice in the state, demonstrating through hydrologic and hydraulic analyses performed in accordance with standard engineering practice that a proposed development will not result in any increase (0.00 feet) in flood levels within the community during the occurrence of a base flood event.
   72. “Physical Map Revision (PMR)” is FEMA’s action whereby one or more map panels are physically revised and republished.
   73. “Recreational Vehicle” means a vehicle which is:
       1. Built on a single chassis;
       2. Four-hundred square feet (400 sq.ft) or less when measured at the largest horizontal projection;
       3. Designed to be self-propelled or permanently towable by a light duty truck; and
       4. Designed primarily, not for use as a permanent dwelling but, as temporary living quarters for recreational, camping, travel, or seasonal use.
   74. “Regulatory Floodway” means the channel of a river or other watercourse and the adjacent land areas that must be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation more than a designated height.
   75. “Riverine” means relating to, formed by, or resembling a river (including tributaries), stream, brook, creek, etcetera, which can be intermittent or perennial.
   76. “Section 1316” means to the section of the National Flood Insurance Act of 1968, as amended, which provides for the denial of flood insurance coverage for any property that the Administrator finds has been declared by a duly constituted State or local authority to be in violation of State or local floodplain management regulations. Section 1316 is issued for a property, not a property owner, and remains with the property even after a change of ownership.
   77. “Special Flood Hazard Area”—see Area of Special Flood Hazard.
   78. “Start of Construction” means 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 and eighty (180) days of the permit date. The actual start means either the first placement of permanent construction of a structure on a site, such as the pouring of slab or footings, the installation of piles, the construction of columns, or any work beyond the stage of excavation; or the placement of a manufactured home on a foundation. Permanent construction does not include land preparation, such as clearing, grading and filling; nor does it include the installation of streets and/or walkways; nor does it include excavation for a basement, footings, piers, or foundations or the erection of temporary forms; nor does it include the installation on the property of accessory structures, such as garages or sheds not occupied as dwelling units or not part of the main structure. For a substantial improvement, the actual start of construction means the first alteration of any wall, ceiling, floor, or other structural part of a building, whether or not that alteration affects the external dimensions of the building.
   79. “Structure for Floodplain Management Purposes” means a walled and roofed building, culvert, bridge, dam, or a gas or liquid storage tank that is principally above ground, as well as a manufactured home.
   80. “Structure for insurance purposes” means:
       1. A building with two or more outside rigid walls and a fully secured roof, which is affixed to a permanent site.
       2. A manufactured home (“a manufactured home,” also known as a mobile home, is a structure: built on a permanent chassis, transported to its site in one or more sections, and affixed to a permanent foundation); or
       3. A travel trailer without wheels built on a chassis and affixed to a permanent foundation, that is regulated under the community's floodplain management and building ordinances or laws.
       4. For insurance purposes, “structure” does not mean a recreational vehicle or a park trailer or other similar vehicle, except as described in paragraph (3) of this definition, or a gas or liquid storage tank.
   81. “Substantial Damage” means damage of any origin sustained by a structure whereby the cost of restoring the structure to its pre-damaged condition would equal or exceed fifty percent (50%) of the market value of the structure before the damage occurred.
   82. “Substantial Improvement” means any reconstruction, rehabilitation, addition, or other improvement of a structure, the cost of which equals or exceeds fifty percent (50%) 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.
       1. The term does not, however, include:
       2. Any project for improvement of a structure to correct existing violations of state or local health, sanitary, or safety code specifications that have been identified by the local code enforcement official and are the minimum necessary to assure safe living conditions; or
       3. Any alteration of a “historic structure”, if the alteration will not preclude the structure's continued designation as a “historic structure.”
   83. “Variance” means a grant of relief by a community from the terms of a flood plain management regulation.
   84. “Violation” means the failure of a structure or other development to be fully compliant with the community's flood plain management regulations. A structure or other development without the elevation certificate, other certifications, or other evidence of compliance required in Sections 44 CFR 60.3(b)(5), (c)(4), (c)(10), (d)(3), (e)(2), (e)(4), or (e)(5) is presumed to be in violation until such time as that documentation is provided.
   85. “Water surface elevation” means the height, in relation to the North American Vertical Datum (NAVD) of 1988, (or other datum, where specified) of floods of various magnitudes and frequencies, such as the 1-percent-annual-chance flood event, in the flood plains of coastal or riverine areas.
   86. “Watercourse” means the channel and banks of an identifiable water in a creek, brook, stream, river, ditch or other similar feature.