Chapter 16.62 — FLOODPLAIN MANAGEMENT

Note: Prior ordinance history: Ords. 2234-88 and 2377-91.

Article 1 Scope and Administration

(a) Title. This chapter, in combination with the flood provisions of California Code of Regulations Title 24, the California Building Standards Code (hereinafter "building codes," consisting of the Part 2 (building), Part 2.5 (residential), Part 10 (existing building), and related codes), shall be known as the Floodplain Management Regulations of the city of Sunnyvale (hereinafter "these regulations").

(b) Statutory Authority. Legislature of the state of California has, in Government Code Articles 65302, 65560, and 65800, conferred upon local governments the authority to adopt regulations designed to promote the public health, safety, and general welfare of its citizenry.

(c) Scope. The provisions of these regulations, in combination with the flood provisions of the building codes, shall apply to all proposed development entirely or partially in flood hazard areas established in Section 16.62.110(b) of these regulations.

(d) Purposes and Objectives. The purposes and objectives of these regulations and the flood load and flood resistant construction requirements of the building codes are to promote the public health, safety and general welfare and to minimize public and private losses due to flood conditions in specific flood hazard areas through the establishment of comprehensive regulations for management of flood hazard areas, designed to:

(1) Minimize unnecessary disruption of commerce, access and public service during times of flooding.

(2) Require the use of appropriate construction practices in order to prevent or minimize future flood damage.

(3) Manage the alteration of natural floodplains, stream channels and shorelines to minimize the impact of development on the natural and beneficial functions of the floodplain.

(4) Manage filling, grading, dredging, mining, paving, excavation, drilling operations, storage of equipment or materials, and other development which may increase flood damage or erosion potential.

(5) Prevent or regulate the construction of flood barriers which will divert floodwater or increase flood hazards.

(6) Contribute to improved construction techniques in the floodplain.

(7) Minimize damage to public and private facilities and utilities.

(8) Help maintain a stable tax base by providing for the sound use and development of flood hazard areas.

(9) Minimize the need for rescue and relief efforts associated with flooding.

(10) Ensure that property owners, occupants, and potential owners are aware of property located in flood hazard areas.

(11) Minimize the need for future expenditure of public funds for flood control projects and response to and recovery from flood events.

(12) Meet the requirements of the National Flood Insurance Program for community participation as set forth in Title 44 Code of Federal Regulations, Section 59.22.

(e) Coordination with California Building Standards Code. Pursuant to the requirement established in state statute that the city administer and enforce the California Building Standards Code, the city council hereby acknowledges that the building codes contain certain provisions that apply to the design and construction of buildings and structures in flood hazard areas. Therefore, these regulations are intended to be administered and enforced in conjunction with the building codes.

(f) Warning. The degree of flood protection required by these regulations and the building codes is considered reasonable for regulatory purposes and is based on scientific and engineering considerations. Larger floods can and will occur. Flood heights may be increased by manmade or natural causes. Enforcement of these regulations and the building codes does not imply that land outside the special flood hazard areas, or that uses permitted within such flood hazard areas, will be free from flooding or flood damage. The flood hazard areas and base flood elevations contained in the Flood Insurance Study and shown on Flood Insurance Rate Maps and the requirements of Title 44 Code of Federal Regulations, Sections 59 and 60 may be revised by the Federal Emergency Management Agency, requiring this community to revise these regulations to remain eligible for participation in the National Flood Insurance Program. No guaranty of vested use, existing use, or future use is implied or expressed by compliance with these regulations.

(g) Disclaimer of Liability. These regulations shall not create liability on the part of the city of Sunnyvale, any officer or employee thereof, the state of California, or the Federal Emergency Management Agency, for any flood damage that results from reliance on these regulations or any administrative decision lawfully made hereunder. The floodplain administrator and any employee charged with the enforcement of these regulations, while acting for the community in good faith and without malice in the discharge of the duties required by these regulations or other pertinent law or ordinance, shall not thereby be rendered liable personally and is hereby relieved from personal liability for any damage accruing to persons or property as a result of any act or by reason of an act or omission in the discharge of official duties. Any suit instituted against an officer or employee because of an act performed by that officer or employee in the lawful discharge of duties and under the provisions of these regulations shall be defended by a legal representative of the community until the final termination of the proceedings. The floodplain administrator and any subordinate shall not be liable for cost in any action, suit or proceeding that is instituted in pursuance of the provisions of these regulations.

(h) Other Laws. The provisions of these regulations shall not be deemed to nullify any provisions of local, state or federal law.

(i) Abrogation and Greater Restrictions. These regulations supersede any ordinance in effect in flood hazard areas. However, these regulations are not intended to repeal, abrogate or impair any existing ordinances including land development regulations, subdivision regulations, zoning ordinances, stormwater management regulations, or building codes, nor any existing easements, covenants, or deed restrictions. In the event of an overlap or conflict between these regulations and any other ordinance, code, regulation, easement,

covenant, or deed restriction, the more restrictive shall govern.

(j) Severability. If any section, subsection, sentence, clause or phrase of this ordinance is, for any reason, declared by the courts to be unconstitutional or invalid, such decision shall not affect the validity of the ordinance as a whole, or any part thereof, other than the part so declared. (Ord. 3220-23, 9/26/2023)

(a) General Applicability. These regulations, in conjunction with the building codes, provide minimum requirements for development located in flood hazard areas, including the subdivision of land; filling, grading and other site improvements; installation of utilities; installation, placement and replacement of manufactured homes; placement of recreational vehicles; installation of tanks; temporary structures and temporary or permanent storage; utility and miscellaneous Group U buildings and structures; certain building work exempt from permit under the building codes; and flood control projects.

(b) Establishment of Flood Hazard Areas. The Flood Insurance Study (FIS) for the county of Santa Clara, California and incorporated areas dated December 19, 1997, and all subsequent amendments and revisions, and the accompanying Flood Insurance Rate Maps (FIRM), and all subsequent amendments and revisions to such maps, are hereby adopted by reference as a part of these regulations and serve as the basis for establishing flood hazard areas. Where the building code establishes flood hazard areas, such areas are established by this section. Additional maps and studies, when specifically adopted, supplement the FIS and FIRMs to establish additional flood hazard areas. Maps and studies that establish flood hazard areas are available at the City of Sunnyvale, Department of Public Works, 456 W. Olive Ave., Sunnyvale, CA 94086.

(c) Interpretation. In the interpretation and application of these regulations, 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.

(Ord. 3220-23, 9/26/2023)

(a) Designation. The director of Community Development is designated the floodplain administrator. The floodplain administrator shall have the authority to delegate performance of certain duties to other employees.

(b) General Authority. The floodplain administrator is authorized and directed to administer and enforce these regulations. The floodplain administrator shall have the authority to render interpretations of these regulations and to establish policies and procedures in order to clarify the application of its provisions. Such interpretations, policies and procedures shall be consistent with the intent and purpose of these regulations and the flood provisions of the building code and shall not have the effect of waiving specific requirements without the granting of a variance pursuant to Section 16.62.160 of these regulations. The

floodplain administrator is authorized to waive the submission of site plans, construction documents, and other data that are required by these regulations but that are not required to be prepared by a qualified California (CA) licensed land surveyor or civil engineer when it is found that the nature of the proposed development is such that the review of such submissions is not necessary to ascertain compliance with these regulations.

(c) Coordination. The floodplain administrator shall coordinate with and provide comments to the building official to administer and enforce the flood provisions of the building code and to ensure compliance with the applicable provisions of these regulations. The floodplain administrator and the building official have the authority to establish written procedures for reviewing applications and conducting inspections for buildings and for administering and documenting determinations of substantial improvement and substantial damage made pursuant to Section 16.62.120(e) of these regulations.

(d) Duties. The floodplain administrator, in coordination with other pertinent offices of the community, shall:

(1) Review all permit applications and plans to determine whether proposed development is located in flood hazard areas.

(2) Review all applications and plans for development in flood hazard areas for compliance with these regulations.

(3) Review, in coordination with the building official, required design certifications and documentation of elevations specified by the building code to determine that such certifications and documentations are complete.

(4) Review applications and plans for modification of any existing development in flood hazard areas for compliance with these regulations.

(5) Require development in flood hazard areas to be reasonably safe from flooding and to be designed and constructed with methods, practices and materials that minimize flood damage.

(6) Interpret flood hazard area boundaries and provide available flood elevation and flood
hazard information.

(7) Determine whether additional flood hazard data shall be obtained from other sources
or developed by the applicant.

(8) Complete the appropriate section of the California Department of Housing and
Community Development Department Floodplain Ordinance Compliance
Certification for Manufactured Home/Mobile home Installations when submitted by
applicants.

(9) Review requests submitted to the building official seeking approval to modify the
strict application of the flood load and flood resistant construction requirements of the
building code, to determine whether such requests require consideration as a variance
pursuant to Section 16.62.160 of these regulations.

(10) Coordinate with the building official and others to identify and investigate damaged
buildings located in flood hazard areas and inform owners of the requirement to
obtain permits for repairs.

(11) Require applicants who submit hydrologic and hydraulic engineering analyses to support permit applications to submit to FEMA the data and information necessary to maintain the Flood Insurance Rate Maps when the analyses indicate changes in base flood elevations, flood hazard area boundaries, or floodway designations; such submissions shall be made within six months of such data becoming available.

(12) Require applicants who propose alteration of a watercourse to notify adjacent communities and the NFIP State Coordinating Agency, and to submit copies of such notifications to the Federal Emergency Management Agency (FEMA).

(13) Inspect development in accordance with Section 16.62.140 of these regulations and inspect flood hazard areas to determine when development is undertaken without issuance of permits.

(14) Prepare comments and recommendations for consideration when applicants seek variances for development other than buildings in accordance with Section 16.62.150 of these regulations.

(15) Cite violations in accordance with Section 16.62.160 of these regulations.

(16) Notify FEMA when the corporate boundaries of the city have been modified and provide a map and legal description of the changes in the corporate boundaries.

(e) Substantial Improvement and Substantial Damage Determinations. For applications for building permits to improve buildings and structures, including alterations, movement, enlargement, replacement, repair, additions, rehabilitations, renovations, substantial improvements, repairs of substantial damage, and any other improvement of or work on such buildings and structures, the floodplain administrator, in coordination with the building official, shall:

(1) Estimate the market value, or require the applicant to obtain an appraisal of the market value prepared by a qualified independent appraiser, of the building or structure before the start of construction of the proposed work; 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 the damaged building to its pre-damaged condition, or the combined costs of improvements and repairs, when 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.

(4) Notify the applicant when it is determined that the work constitutes substantial improvement or repair of substantial damage and that compliance with the flood resistant construction requirements of the building code is required and notify the applicant when it is determined that work does not constitute substantial improvement or repair of substantial damage.

(f) Department Records. In addition to the requirements of the building code and these regulations, and regardless of any limitation on the period required for retention of public records, the floodplain administrator shall maintain and permanently keep and make available for public inspection all records that are necessary for the administration of these

regulations and the flood provisions of the building codes, including Flood Insurance Studies and Flood Insurance Rate Maps; documents from FEMA that amend or revise FIRMs; records of issuance of permits and denial of permits; determinations of whether proposed work constitutes substantial improvement or repair of substantial damage; required certifications and documentation specified by the building codes and these regulations; notifications to adjacent communities, FEMA, and the state related to alterations of watercourses; assurance that the flood carrying capacity of altered waterways will be maintained; documentation related to variances, including justification for issuance or denial; and records of enforcement actions taken pursuant to these regulations and the flood resistant provisions of the building codes. (Ord. 3220-23, 9/26/2023)

(a) Information for Development in Flood Hazard Areas. The site plan or construction documents for any development subject to the requirements of these regulations shall be drawn to scale and shall include, as applicable to the proposed development:

(1) Delineation of flood hazard areas; floodway boundaries and flood zone(s); base flood elevation(s); ground elevations; proposed filling, grading, and excavation; and drainage patterns and facilities when necessary for review of the proposed development.

(2) Where base flood elevations or floodway data are not included on the FIRM or in the Flood Insurance Study, they shall be established in accordance with subsections (b) or (c) of this section.

(3) Where the parcel on which the proposed development will take place will have more than 50 lots or is larger than five acres and base flood elevations are not included on the FIRM or in the Flood Insurance Study, such elevations shall be established in accordance with subsection (b)(2) of this section.

(4) Location of the proposed activity and proposed structures; locations of water supply, sanitary sewer, and other utilities; and locations of existing buildings and structures.

(5) Location, extent, amount, and proposed final grades of any filling, grading, or excavation.

(6) Where the placement of fill is proposed, the amount, type, and source of fill material; compaction specifications; a description of the intended purpose of the fill areas; and evidence that the proposed fill areas are the minimum necessary to achieve the intended purpose.

(7) Existing and proposed alignment of any proposed alteration of a watercourse.

(b) Information in Flood Hazard Areas Without Base Flood Elevations (Approximate Zone A). Where flood hazard areas are delineated on the FIRM and base flood elevation data have not been provided, the floodplain administrator is authorized to:

(1) Require the applicant to include base flood elevation data prepared by a qualified CA licensed civil engineer in accordance with currently accepted engineering practices. Such analyses shall be performed and sealed by a qualified CA licensed civil

engineer. Studies, analyses and computations shall be submitted in sufficient detail to allow review and approval by the floodplain administrator. The accuracy of data submitted for such determination shall be the responsibility of the applicant.

(2) Obtain, review, and provide to applicants, base flood elevation and floodway data available from a federal or state agency or other source or require the applicant to obtain and use base flood elevation and floodway data available from a federal or state agency or other source.

(3) Where base flood elevation and floodway data are not available from another source, where the available data are deemed by the floodplain administrator to not reasonably reflect flooding conditions, or where the available data are known to be scientifically or technically incorrect or otherwise inadequate:

(4) Require the applicant to include base flood elevation data in accordance with subsection (b)(1) of this section; or

(5) Specify that the base flood elevation is two feet above the highest adjacent grade at the location of the development, provided there is no evidence indicating flood depths have been or may be greater than two feet.

(6) Where the base flood elevation data are to be used to support a request for a Letter of Map Change from FEMA, advise the applicant that the analyses shall be prepared by a qualified CA licensed civil engineer in a format required by FEMA, and that it shall be the responsibility of the applicant to satisfy the submittal requirements and pay the processing fees.

(c) Additional Analyses and Certifications. As applicable to the location and nature of the proposed development activity, and in addition to the requirements of these regulations, the applicant shall have the following analyses signed and sealed by a qualified CA licensed civil engineer for submission with the site plan and construction documents:

(1) For development activities proposed to be located in a floodway, a floodway encroachment analysis that demonstrates that the encroachment of the proposed development will not cause any increase in base flood elevations; where the applicant proposes to undertake development activities that do increase base flood elevations, the applicant shall submit such analysis to FEMA as specified in subsection (d) of this section, and shall submit the Conditional Letter of Map Revision, when issued by FEMA, with the site plan and construction documents.

(2) For development activities proposed to be located in a riverine flood hazard area where base flood elevations are included in the Flood Insurance Study or on the FIRM but floodways have not been designated, hydrologic and hydraulic analyses that demonstrate that the cumulative effect of the proposed development, when combined with all other existing and anticipated flood hazard area encroachments, will not increase the base flood elevation more than one foot at any point within the community. This requirement does not apply in isolated flood hazard areas not connected to a riverine flood hazard area or in flood hazard areas identified as Zone AO or Zone AH.

(3) For alteration of a watercourse, an engineering analysis prepared in accordance with standard engineering practices that demonstrates the flood-carrying capacity of the

altered or relocated portion of the watercourse will not be decreased, and certification that the altered watercourse shall be maintained in a manner which preserves the channel's flood-carrying capacity. The applicant shall submit the analysis to FEMA as specified in subsection (d) of this section. The applicant shall notify the chief executive officer of adjacent communities and the California Department of Water Resources. The floodplain administrator shall maintain a copy of the notification in the permit records and shall submit a copy to FEMA.

(d) Submission of Additional Data. When additional hydrologic, hydraulic or other engineering data, studies, and additional analyses are submitted to support an application, the applicant has the right to seek a Letter of Map Change from FEMA to change the base flood elevations, change floodway boundaries, or change boundaries of flood hazard areas shown on FIRMs, and to submit such data to FEMA for such purposes. The analyses shall be prepared by a qualified CA licensed civil engineer in a format required by FEMA. Submittal requirements and processing fees shall be the responsibility of the applicant. Provided FEMA issues a Conditional Letter of Map Revision, construction of proposed flood control projects and land preparation for development are permitted, including clearing, excavation, grading, and filling. Permits for construction of buildings shall not be issued until the applicant satisfies the FEMA requirements for issuance of a letter of map revision. (Ord. 3220-23, 9/26/2023)

(a) Inspections. Development for which a building permit is required shall be subject to inspection. Approval as a result of an inspection shall not be construed to be an approval of a violation of the provisions of these regulations or the building code. Inspections presuming to give authority to violate or cancel the provisions of these regulations or the building code or other ordinances shall not be valid. The floodplain administrator shall inspect flood hazard areas from time to time to determine when development is undertaken without issuance of a permit.

(b) Inspections of Manufactured Homes Installations. The floodplain administrator shall make or cause to be made, inspections of installation and replacement of manufactured homes in flood hazard areas for which a building permit is required. Upon installation of a manufactured home and receipt of the elevation certification required in Section 16.62.330(a) of these regulations, the floodplain administrator shall inspect the installation or have the installation inspected.

(c) Buildings and Structures. The building official shall make or cause to be made, inspections for buildings and structures in flood hazard areas authorized by permit, in accordance with the building code:

(1) Lowest Floor Elevation. Upon placement of the lowest floor, including the basement, and prior to further vertical construction, certification of the elevation required in the building code shall be prepared by a CA licensed land surveyor or civil engineer and submitted to the building official.

(2) Final Inspection. Prior to the final inspection, certification of the elevation required in the building code shall be prepared by a CA licensed land surveyor or civil engineer and submitted to the building official.

(Ord. 3220-23, 9/26/2023)

(a) Nature of Variances.

(1) The considerations and conditions for variances set forth in this section are based on
the general principle of zoning law that variances pertain to a piece of property and
are not personal in nature. A variance may be issued for a parcel of property with
physical characteristics so unusual that complying with the requirements of these
regulations would create an exceptional hardship to the applicant or the surrounding
property owners. The characteristics must be unique to the property and not be shared
by adjacent parcels. The unique characteristic must pertain to the land itself, not to
the structure, its inhabitants, or the property owners. The issuance of a variance is for
floodplain management purposes only. Federal flood insurance premium rates are
determined by the National Flood Insurance Program according to actuarial risk and
will not be modified by the granting of a variance.

(2) It is the duty of the city council to promote public health, safety and welfare and
minimize losses from flooding. This duty is so compelling and the implications of
property damage and the cost of insuring a structure built below flood level are so
serious that variances from the elevation or other requirements in the building codes
should be quite rare. The long term goal of preventing and reducing flood loss and
damage, and minimizing recovery costs, inconvenience, danger, and suffering, can
only be met when variances are strictly limited. Therefore, the variance requirements
in these regulations are detailed and contain multiple provisions that must be met
before a variance can be properly issued. The criteria are designed to screen out those
situations in which alternatives other than a variance are more appropriate.

(b) Variances; General. The city council shall hear and decide requests for variances from the strict application of these regulations.

(c) Limitations on Authority. The city council shall base its determination on technical justifications submitted by applicants, the considerations and conditions set forth in this section, the comments and recommendations of the floodplain administrator and building official, as applicable, and has the right to attach such conditions to variances as it deems necessary to further the purposes and objectives of these regulations and the building code.

(d) Records. The floodplain administrator shall maintain a permanent record of all variance actions, including justification for issuance.

(e) Historic Structures. A variance is authorized to be issued for the repair, improvement, or rehabilitation of a historic structure upon a determination that the proposed repair, improvement, or rehabilitation will not preclude the structure's continued designation as a historic structure, and the variance is the minimum necessary to preserve the historic character and design of the structure. When the proposed work precludes the structure's continued designation as a historic building, a variance shall not be granted and the structure and any repair, improvement, and rehabilitation shall be subject to the requirements of the building code.

(f) Restrictions in Floodways. A variance shall not be issued for any proposed development in a floodway when any increase in flood levels would result during the base flood discharge,

as evidenced by the applicable analyses required in Section 16.62.130(c)(1) of these regulations.

(g) Functionally Dependent Uses. A variance is authorized to be issued for the construction or substantial improvement necessary for the conduct of a functionally dependent use provided the criteria in Section 1612 of the building code (CCR Title 24 Part 2) or Section R322 of the residential code (CCR Title 24 Part 2.5) are met, as applicable, and the variance is the minimum necessary to allow the construction or substantial improvement, and that all due consideration has been given to use of methods and materials that minimize flood damages during the base flood and create no additional threats to public safety.

(h) Considerations for Issuance of Variances. In reviewing applications for variances, all technical evaluations, all relevant factors, all other requirements of these regulations and the building code, as applicable, and the following shall be considered:

(1) The danger that materials and debris may be swept onto other lands resulting in further injury or damage.

(2) The danger to life and property due to flooding or erosion damage.

(3) The susceptibility of the proposed development, including contents, to flood damage and the effect of such damage on current and future owners.

(4) The importance of the services provided by the proposed development to the community.

(5) The availability of alternate locations for the proposed development that are not subject to flooding or erosion and the necessity of a waterfront location, where applicable.

(6) The compatibility of the proposed development with existing and anticipated development.

(7) The relationship of the proposed development to the comprehensive plan and floodplain management program for that area.

(8) The safety of access to the property in times of flood for ordinary and emergency vehicles.

(9) The expected heights, velocity, duration, rate of rise and debris and sediment transport of the floodwater and the effects of wave action, if applicable, expected at the site.

(10) 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, streets and bridges.

(i) Conditions for Issuance of Variances. Variances shall only be issued upon:

(1) Submission by the applicant of a showing of good and sufficient cause that the unique characteristics of the size, configuration or topography of the site limit compliance with any provision of these regulations or renders the elevation standards of the building code inappropriate.

(2) A determination that failure to grant the variance would result in exceptional hardship

due to the physical characteristics of the land that render the lot undevelopable.

(3) A determination that the granting of a variance will not result in increased flood heights, additional threats to public safety, extraordinary public expense, nor create nuisances, cause fraud on or victimization of the public or future property owners, or conflict with existing local laws or ordinances.

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

(5) When the request is to allow construction of the lowest floor of a new building or substantial improvement of a building below the base flood elevation, notification to the applicant in writing over the signature of the floodplain administrator specifying the difference between the base flood elevation and the proposed elevation of the lowest floor, stating that issuance of a variance to construct below the elevation required in the building code will result in increased premium rates for federal flood insurance up to amounts as high as $25.00 for $100.00 of insurance coverage, and that such construction below the required elevation increases risks to life and property.

(Ord. 3220-23, 9/26/2023)

(a) Violations. In addition to any other remedies provided by law, any development in any flood hazard area that is being performed without an issued permit or that is in conflict with an issued permit shall be deemed a violation. A building or structure without the documentation of the elevation of the lowest floor, other required design certifications, or other evidence of compliance required by these regulations or the building code, is presumed to be a violation until such time as required documentation is submitted. Violation of the requirements shall constitute a misdemeanor.

(b) Authority. The floodplain administrator is authorized to serve notices of violation or stop work orders to owners of property involved, to the owner's agent, or to the person or persons doing the work for development that is not within the scope of the building codes, but is regulated by these regulations and that is determined to be a violation.

(c) Unlawful Continuance. Any person who shall continue any work after having been served with a notice of violation or a stop work order, except such work as that person is directed to perform to remove or remedy a violation or unsafe condition, shall be subject to penalties as prescribed in Chapters 1.04, 1.05, and 1.06 of this code. (Ord. 3220-23, 9/26/2023)

Article 2 Definitions

The following words and terms shall, for the purposes of these regulations, have the meanings shown herein. Where terms are not defined in these regulations and are defined in the building code (CCR Title 24 Part 2) and used in the residential code (CCR Title 24 Part 2.5), such terms shall have the meanings ascribed to them in those codes. Where terms are not defined in these regulations or the building code, such terms shall have ordinarily accepted meanings such as the context implies. (Ord. 3220-23, 9/26/2023)

(a) "A"

(1) "Accessory structure" means a structure on the same parcel of property as a principal
structure and the use of which is incidental to the use of the principal structure. For
floodplain management purposes, the term includes only accessory structures used for
parking and storage.

(2) "Alteration of a watercourse" means a dam, impoundment, channel relocation, change
in channel alignment, channelization, or change in cross-sectional area of the channel
or the channel capacity, or any other form of modification which may alter, impede,
retard or change the direction and/or velocity of the riverine flow of water during
conditions of the base flood.

(3) "ASCE 24" means the standard Flood Resistant Design and Construction, referenced
by the building code, developed and published by the American Society of Civil
Engineers, Reston, VA. Where cited, ASCE 24 refers to the edition of the standard
that is referenced by the building code.

(b) "B"

(1) "Base flood" means the flood having a one-percent chance of being equaled or exceeded in any given year. [Also defined in CCR Title 24 Part 2.]

(2) "Base flood elevation" means the elevation of the base flood, including wave height, relative to the National Geodetic Vertical Datum (NGVD), North American Vertical Datum (NAVD) or other datum specified on the Flood Insurance Rate Map (FIRM). [Also defined in CCR Title 24 Part 2.]

(3) "Basement" means, for the purpose of floodplain management, the portion of a building having its floor subgrade (below ground level) on all sides. [Also defined in CCR Title 24 Part 2.]

(4) "Building code" means California Code of Regulations Title 24, the California Building Standards Code, the family of building codes specifically adopted by the state of California and composed of:

(A) Part 2, applicable to buildings and structures other than dwellings within the scope of this part.

(B) Part 2.5, applicable to one- and two-family dwellings and townhouses not more than three stories, and accessory structures.

(C) Part 10, applicable to existing buildings (as defined in that code).

(D) Other specified codes.

(c) "C" — reserved.

(d) "D"

(1) "Design flood" means the flood associated with the greater of the following two areas: [Also defined in CCR Title 24 Part 2.]

(A) Area with a flood plain subject to a one-percent or greater chance of flooding in any year.

(B) Area designated as a flood hazard area on a community's flood hazard map, or otherwise legally designated.

(2) "Design flood elevation" means the elevation of the "design flood," including wave height, relative to the datum specified on the community's legally designated flood hazard map. In areas designated as Zone AO, the design flood elevation shall be the elevation of the highest existing grade of the building's perimeter plus the depth number (in feet) specified on the flood hazard map. In areas designated as Zone AO where a depth number is not specified on the map, the depth number shall be taken as being equal to two feet (610 mm). [Also defined in CCR Title 24 Part 2.]

(3) "Development" means any manmade change to improved or unimproved real estate, including, but not limited to, buildings or other structures, temporary structures, temporary or permanent storage of materials, mining, dredging, filling, grading, paving, excavations, drilling operations, flood control projects, and other land- disturbing activities.

(e) "E"

(1) "Encroachment" means the placement of fill, excavation, buildings, permanent structures or other development into a flood hazard area which may impede or alter the flow capacity of riverine flood hazard areas.

(2) "Exceptional hardship" means, for the purpose of variances from these regulations or the building code, the exceptional difficulty that would result from a failure to grant a requested variance. Mere economic or financial hardship is not exceptional. Inconvenience, aesthetic considerations, physical handicaps, personal preferences, or the disapproval of one's neighbors do not, as a rule, qualify as exceptional hardships. All of these circumstances can be resolved through other means without granting variances, even when the alternatives are more expensive or require the property owner to build elsewhere or put the parcel to a different use than originally intended.

(3) "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) was completed before December 19, 1997.

(4) "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 manufactured 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).

(f) "F"

(1) "FIRM" means Flood Insurance Rate Map as defined in this section.

(2) "FIS" means Flood Insurance Study as defined in this section.

(3) "Flood or flooding" means a general and temporary condition of partial or complete inundation of normally dry land from:

(A) The overflow of inland or tidal waters.

(B) The unusual and rapid accumulation or runoff of surface waters from any source.

(C) Mudslides (i.e., mudflows) which are proximately caused by flooding.

(4) "Flood control project" means a dam or barrier design and constructed to keep water away from or out of a specified area, including, but not limited to levees, floodwalls, and channelization.

(5) "Flood damage-resistant materials" means any construction material capable of withstanding direct and prolonged contact with floodwaters without sustaining any damage that requires more than cosmetic repair. [Also defined in CCR Title 24 Part 2.]

(6) "Flood hazard area" means the greater of the following two areas: [Also defined in CCR Title 24 Part 2.]

(A) The area within a floodplain subject to a one-percent or greater chance of flooding in any year.

(B) The area designated as a flood hazard area on the community's flood hazard map, or otherwise legally designated.

(7) "Flood Insurance Rate Map" or "FIRM" means an official map of a community on which the Federal Emergency Management Agency (FEMA) has delineated both the special flood hazard areas and the risk premium zones applicable to the community. [Also defined in CCR Title 24 Part 2.]

(8) "Flood Insurance Study" or "FIS" means the official report provided by the Federal Emergency Management Agency containing the Flood Insurance Rate Map (FIRM), the Flood Boundary and Floodway Map (FBFM), the water surface elevation of the base flood and supporting technical data. [Also defined in CCR Title 24 Part 2.]

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

(10) "Floodway" means the channel of the river, creek 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. [Also defined in CCR Title 24 Part 2.]

(11) "Fraud or victimization" means, for the purpose of variances from these regulations or the building code, the intentional use of deceit to deprive another of rights or property, making a victim of the deprived person or the public. As it pertains to buildings granted variances to be constructed below the elevation required by the building code, future owners or tenants of such buildings and the community as a whole may bear the burden of increased risk of damage from floods, increased cost of flood insurance, and increased recovery costs, inconvenience, danger, and suffering.

(12) "Functionally dependent use" means a use that cannot perform its intended purpose unless it is located or carried out in close proximity to water, including only docking facilities, port facilities necessary for the loading or unloading of cargo or passengers, and shipbuilding or ship repair facilities. The term does not include long-term storage, manufacture, sales or service facilities.

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

(g) "G" — reserved.

(h) "H"

(1) "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 or a
district preliminarily determined by the Secretary to qualify as a registered
historic district;

(C) Individually listed on the inventory of historic places maintained by the
California Office of Historic Preservation; or

(D) Individually listed on a local inventory of historic places in communities with
historic preservation programs that have been certified by the California Office
of Historic Preservation.

(i) "I" — reserved.

(j) "J" — reserved.

(k) "K" — reserved.

(l) "L"

(1) "Letter of Map Change (LOMC)" means an official determination issued by FEMA

that amends or revises an effective Flood Insurance Rate Map or Flood Insurance Study. Letters of Map Change include:

(A) Letter of Map Amendment (LOMA): An amendment based on technical data showing that a property was incorrectly included in a designated special flood hazard area. A LOMA amends the current effective Flood Insurance Rate Map and establishes that a specific property, portion of a property, or structure is not located in a special flood hazard area.

(B) Letter of Map Revision (LOMR): A revision based on technical data that may show changes to flood zones, flood elevations, special flood hazard area boundaries and floodway delineations, and other planimetric features.

(C) Letter of Map Revision Based on Fill (LOMR-F): A determination that a structure or parcel of land has been elevated by fill above the base flood elevation and is, therefore, no longer located within the special flood hazard area. In order to qualify for this determination, the fill must have been permitted and placed in accordance with the community's floodplain management regulations.

(D) Conditional Letter of Map Revision (CLOMR): A formal review and comment as to whether a proposed flood protection project or other project complies with the minimum NFIP requirements for such projects with respect to delineation of special flood hazard areas. A CLOMR does not revise the effective Flood Insurance Rate Map or Flood Insurance Study; upon submission and approval of certified as-built documentation, a Letter of Map Revision may be issued by FEMA to revise the effective FIRM.

(2) "Light-duty truck" means, as defined in 40 C.F.R. 86.082-2, any motor vehicle rated at 8,500 pounds Gross Vehicular Weight Rating or less which has a vehicular curb weight of 6,000 pounds or less and which has a basic vehicle frontal area of 45 square feet or less, which is:

(A) Designed primarily for purposes of transportation of property or is a derivation of such a vehicle, or

(B) Designed primarily for transportation of persons and has a capacity of more than 12 persons; or

(C) Available with special features enabling off-street or off-highway operation and use.

(3) "Lowest floor" means the lowest floor of the lowest enclosed area, including basement, but excluding any unfinished or flood-resistant enclosure, usable solely for vehicle parking, building access or limited storage provided that such enclosure is not built so as to render the structure in violation of the non-elevation requirements of the building codes. [Also defined in CCR Title 24 Part 2.]

(m) "M"

(1) "Manufactured home" means a structure that is transportable in one or more sections, built on a permanent chassis, designed for use as a single-family dwelling with or without a permanent foundation when connected to the required utilities, and

constructed to the Manufactured Home Construction and Safety Standards promulgated by the U.S. Department of Housing and Urban Development. Also see definitions in Health and Safety Code sections 18000(a)(2) and 18001(a). For the purposes of floodplain management, the term also includes mobile homes and recreational vehicles, park trailers, travel trailers and similar transportable structures that are placed on a site for 180 consecutive days or longer.

(2) "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.

(3) "Market value" means the price at which a property will change hands between a willing buyer and a willing seller, neither party being under compulsion to buy or sell and both having reasonable knowledge of relevant facts. As used in these regulations, the term refers to the market value of buildings and structures, excluding the land and other improvements on the parcel. Market value may be established by one of the following methods: (1) Actual Cash Value (replacement cost depreciated for age and quality of construction), (2) tax assessment value adjusted to approximate market value by a factor provided by the Property Appraiser, or (3) a qualified independent appraiser.

(n) "N"

(1) "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) was completed on or after December 19, 1997.

(2) "Nuisance" means that which is injurious to safety or health of an entire community or neighborhood, or any considerable number of persons, or unlawfully obstructs the free passage or use, in the customary manner, of any navigable lake, or river, bay, stream, canal, or basin.

(o) "O" — reserved.

(p) "P"

(1) "Permit" means an official document or certificate issued by the community, or other evidence of approval or concurrence, which authorizes performance of specified development activities that are located in flood hazard areas and that are determined to be compliant with these regulations.

(q) "Q" — reserved.

(r) "R"

(1) "Recreational vehicle" means a vehicle that is built on a single chassis, 400 square feet (37.16 m 2) or less when measured at the largest horizontal projection, designed to be self-propelled or permanently towable by a light-duty truck, and designed primarily not for use as a permanent dwelling but as temporary living quarters for recreational, camping, travel or seasonal use. A recreational vehicle is ready for highway use when 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. Also see definitions in Health and Safety Code section 18010.

(2) "Riverine" means relating to, formed by, or resembling a river (including tributaries), stream, brook, etc.

(s) "S"

(1) "Special flood hazard area (SFHA)" means the land area subject to flood hazards and
shown on a Flood Insurance Rate Map or other flood hazard map as Zone A, AE,
A1-30, A99, AR, AO, AH, V, VO, VE, or V1-30. [Also defined in CCR Title 24 Part
2.]

(2) "Substantial damage" means damage of any origin sustained by a structure whereby
the cost of restoring the structure to its before-damaged condition would equal or
exceed 50 percent of the market value of the structure before the damage occurred.
[Also defined in CCR Title 24 Part 2.]

(3) "Substantial improvement" means any repair, reconstruction, rehabilitation,
alteration, addition or other improvement of a building or structure, the cost of which
equals or exceeds 50 percent of the market value of the structure before the
improvement or repair is started. When the structure has sustained substantial
damage, any repairs are considered substantial improvement regardless of the actual
repair work performed. The term does not, however, include either: [Also defined in
CCR Title 24 Part 2.]

(A) Any project for improvement of a building required to correct existing health,
sanitary or safety code violations identified by the building official and that are
the minimum necessary to assure safe living conditions.

(B) Any alteration of a historic structure provided that the alteration will not
preclude the structure's continued designation as a historic structure.

(t) "T" — reserved.

(u) "U"

(1) "Utility and Miscellaneous Group U" means buildings and structures of an accessory
character and miscellaneous structure not classified in any special occupancy, as
described in the building code.

(v) "V"

(1) "Variance" means a grant of relief from the requirements of these regulations which permits construction in a manner otherwise prohibited and where specific enforcement would result in exceptional hardship.

(2) "Violation" means a development that is not fully compliant with these regulations or the flood provisions of the building code, as applicable.

(w) "W"

(1) "Watercourse" means a river, creek, stream, channel or other topographic feature in, on, through, or over which water flows at least periodically.

(Ord. 3220-23, 9/26/2023)

Article 3 Flood Resistant Development.

(a) Requirements for Buildings and Structures in Flood Hazard Areas. Applications for building and structures within the scope of the building code that are proposed in flood hazard areas shall comply with the applicable requirements of the building code.

(b) Detached Garages and Accessory Storage Structures. Detached garages and accessory storage structures used only for parking or storage are permitted below the base flood elevation provided the garages and accessory storage structures:

(1) Are one story and not larger than 600 square feet in area when located in special flood hazard areas.

(2) Are anchored to resist flotation, collapse or lateral movement resulting from flood loads.

(3) Have flood openings in accordance with the building code.

(4) Have flood damage-resistant materials used below the base flood elevation.

(5) Have mechanical, plumbing and electrical systems, including plumbing fixtures, elevated to or above the base flood elevation plus one foot.

(c) Utility and Miscellaneous Group U. Utility and miscellaneous Group U includes buildings that are accessory in character and miscellaneous structures not classified in any specific occupancy in the building code, including, but not limited to, agricultural buildings, aircraft hangars (accessory to a one- or two-family residence), barns, carports, fences more than six feet (1,829 mm) high, grain silos (accessory to a residential occupancy), greenhouses, livestock shelters, private garages, retaining walls, sheds, stables, and towers. In addition to the building code requirements for fire and life safety, the following shall apply to utility and miscellaneous Group U buildings and structures in flood hazard areas:

(1) New construction and substantial improvement of such buildings and structures shall be anchored to prevent flotation, collapse or lateral movement resulting from flood loads, including the effects of buoyancy, during conditions of the design flood.

(2) New construction and substantial improvement of such buildings and structures, when fully enclosed by walls, shall be elevated such that the lowest floor, including basement, is elevated to or above the design flood elevation in accordance with ASCE 24 or shall be dry floodproofed in accordance with ASCE 24.

(3) Unless dry floodproofed, fully enclosed areas below the design flood elevation shall be constructed in accordance with ASCE 24 and limited to parking, storage, and building access.

(4) When fully enclosed by walls, flood openings shall be installed in accordance with ASCE 24.

(5) Flood damage-resistant materials shall be used below the design flood elevation.

(6) Mechanical, plumbing and electrical systems, including plumbing fixtures, shall be

located or installed in accordance with ASCE 24. (Ord. 3220-23, 9/26/2023)

(a) Minimum Requirements. Subdivision proposals in flood hazard areas, including proposals for manufactured home parks and subdivisions, shall be reviewed to determine that:

(1) Such proposals are consistent with the need to minimize flood damage and will be reasonably safe from flooding.

(2) All public utilities and facilities, such as sewer, gas, electric, communications, and water systems are located and constructed to minimize or eliminate flood damage in accordance with Sections 16.62.320(b) and 16.62.320(c) of these regulations, as applicable, and appropriate codes.

(3) Adequate drainage is provided to reduce exposure to flood hazards; in Zones AH and AO, adequate drainage paths shall be provided to guide floodwater around and away from proposed structures.

(b) Subdivision Requirements. In addition to the requirements of subsection (a) of this section, where any portion of proposed subdivisions, including proposals for manufactured home parks and subdivisions, lies within a flood hazard area, the following shall be required:

(1) The flood hazard area, including floodways, as appropriate, shall be delineated on preliminary subdivision plats.

(2) Where the subdivision has more than 50 lots or is larger than 5 acres and base flood elevations are not included on the FIRM, the base flood elevations determined in accordance with Section 16.62.130(b)(1) of these regulations.

(3) When, as part of a proposed subdivision, fill will be placed to support buildings, the fill shall be placed in accordance with the building code and approval of the subdivision shall require submission of as-built elevations for each filled pad certified by a licensed land surveyor or registered civil engineer.

(Ord. 3220-23, 9/26/2023)

(a) Minimum Requirements. All proposed development in flood hazard areas shall be reviewed to determine that:

(1) Such proposals are consistent with the need to minimize flood damage and will be reasonably safe from flooding.

(2) Where the proposed development has more than 50 lots or is larger than 5 acres and base flood elevations are not included on the FIRM, the base flood elevations determined in accordance with Section 16.62.130(b)(1) of these regulations.

(3) All public utilities and facilities, such as sewer, gas, electric, communications, and water systems are located and constructed to minimize or eliminate flood damage.

(4) Adequate drainage is provided to reduce exposure to flood hazards; in Zones AH and

AO, adequate drainage paths shall be provided to guide floodwater around and away from proposed structures.

(b) Sanitary Sewer Facilities. All new and replaced sanitary sewer facilities, private sewage treatment plants (including all pumping stations and collector systems) and on-site waste disposal systems shall be designed in accordance with Chapter 7, ASCE 24, to minimize or eliminate infiltration of floodwaters into the facilities and discharge from the facilities into flood waters, and impairment of the facilities and systems.

(c) Water Supply Facilities. All new and replaced water supply facilities shall be designed in accordance with the provisions of Chapter 7, ASCE 24, to minimize or eliminate infiltration of floodwaters into the systems.

(d) Development in Floodways. Development, site improvements and land disturbing activity involving fill or regrading shall not be authorized in the floodway unless the floodway encroachment analysis required in Section 16.62.130(c)(1) of these regulations demonstrates the proposed work will not result in any increase in the base flood level during occurrence of the base flood discharge.

(e) Limitations on Placement of Fill. Subject to the limitations of these regulations, fill shall be designed to be stable under conditions of flooding including rapid rise and rapid drawdown of floodwaters, prolonged inundation, and protection against flood-related erosion and scour. In addition to these requirements, when intended to support buildings and structures, fill shall comply with the requirements of the building code. The placement of fill intended to change base flood elevations, change floodway boundaries, or change boundaries of flood hazard areas shown on FIRMs shall be subject to the requirements of Section 16.62.130(d) of these regulations. (Ord. 3220-23, 9/26/2023)

(a) Installation. All manufactured homes installed in flood hazard areas shall be installed by an installer that is licensed pursuant to the Business and Professions Code and shall comply with the requirements of the Department of Housing and Community Development (HCD) and the requirements of these regulations. Permits from the HCD are required where the HCD is the enforcement agency for installation of manufactured homes. In addition, the requirements of this section 16.32.330 apply when the city has enforcement authority. Upon completion of installation and prior to the final inspection by the floodplain administrator, the installer shall submit certification of the elevation of the manufactured home, prepared by a licensed land surveyor or registered civil engineer, to the floodplain administrator.

(b) Foundations. All new and replacement manufactured homes, including substantial improvement of manufactured homes installed in flood hazard areas shall be installed on permanent, reinforced foundations that are designed in accordance with the foundation requirements of Section R322.2 of the residential code (CCR Title 24 Part 2.5) and these regulations. Foundations for manufactured homes subject to subsection (e) of this section are permitted to be reinforced piers or other foundation elements of at least equivalent strength.

(c) Anchoring. All new and replacement manufactured homes to be placed or substantially

improved in a flood hazard area shall be installed using methods and practices which minimize flood damage and shall be securely anchored to an adequately anchored foundation system to resist flotation, collapse and lateral movement. Methods of anchoring are authorized to 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 loads and seismic loads.

(d) General Elevation Requirement. Unless subject to the requirements of subsection (e) of this section, all manufactured homes that are placed, replaced, or substantially improved on sites located: (i) outside of a manufactured home park or subdivision; (ii) in a new manufactured home park or subdivision; (iii) in an expansion to an existing manufactured home park or subdivision; or (iv) in an existing manufactured home park or subdivision upon which a manufactured home has incurred "substantial damage" as the result of a flood, shall be elevated such that the lowest floor, or bottom of the lowest horizontal member of the lowest floor, as applicable to the flood hazard area, is at or above the base flood elevation plus one foot.

(e) Elevation Requirement for Certain Existing Manufactured Home Parks and Subdivisions. Manufactured homes that are not subject to subsection (d) of this section, including manufactured homes that are placed, replaced, or substantially improved on sites located in an existing manufactured home park or subdivision, unless on a site where substantial damage as a result of flooding has occurred, shall be elevated such that the lowest floor, or bottom of the lowest horizontal structural member, as applicable to the flood hazard area, is at or above the base flood elevation plus one foot.

(f) Flood-Damage-Resistant Materials. Materials below elevated manufactured homes shall comply with the flood-damage-resistant materials requirements of Section R322 of the residential code (CCR Title 24 Part 2.5).

(g) Enclosures. Fully enclosed areas below elevated manufactured homes shall comply with the enclosed area requirements of Section R322 of the residential code (CCR Title 24 Part 2.5).

(h) Protection of Mechanical Equipment and Outside Appliances. Mechanical equipment and outside appliances shall be elevated to or above the lowest floor plus one foot or bottom of the lowest horizontal structural member of the manufactured home plus one foot, as applicable to the flood hazard area.

(1) Exception. Where such equipment and appliances are designed and installed to prevent water from entering or accumulating within their components and the systems are constructed to resist hydrostatic and hydrodynamic loads and stresses, including the effects of buoyancy, during the occurrence of flooding up to the elevation required by subsections (d) or (e) of this section, as applicable, the systems and equipment shall be permitted to be located below that elevation. Electrical wiring systems shall be permitted below the design flood elevation provided they conform to the provisions of NFPA 70 (National Electric Code).

(Ord. 3220-23, 9/26/2023; Ord. 3224-24, 2/27/2024)

(a) Temporary Placement. Recreational vehicles in flood hazard areas, shall be placed on a site

for less than 180 consecutive days or shall be fully licensed and ready for highway use. Ready for highway use means the recreational vehicle is on wheels or jacking system, is attached to the site only by quick disconnect type utilities and security devices, and has no permanently attached additions, such as rooms, stairs, decks and porches.

(b) Permanent Placement. Recreational vehicles that do not meet the limitations in subsection (a) for temporary placement shall meet the requirements of section 16.62.330 for manufactured homes. (Ord. 3220-23, 9/26/2023)

(a) General Requirements for Other Development. All development, including man-made changes to improved or unimproved real estate for which specific provisions are not specified in these regulations or the building code, shall:

(1) Be located and constructed to minimize flood damage.

(2) Meet the limitations of Section 16.62.320(d) of these regulations when located in a regulated floodway.

(3) Be anchored to prevent flotation, collapse or lateral movement resulting from hydrostatic loads, including the effects of buoyancy, during conditions of the design flood.

(4) Be constructed of flood damage-resistant materials.

(5) Have mechanical, plumbing, and electrical systems above the design flood elevation or meet the requirements of ASCE 24, except that minimum electric service required to address life safety and electric code requirements is permitted below the design flood elevation provided it conforms to the provisions of the electrical part of the building code for wet locations.

(b) Tanks. Tanks that serve buildings shall comply with the requirements of the building code. Underground and above-ground tanks that serve other purposes shall be designed, constructed, installed and anchored in accordance with ASCE 24.

(c) Requirements for Temporary Structures and Temporary Storage in Flood Hazard Areas. Temporary structures shall be erected for a period of less than 180 days and temporary storage of goods and materials shall be permitted for a period of less than 180 days. Extensions may be granted in accordance with the building code. In addition, the following apply:

(1) Temporary structures shall be anchored to prevent flotation, collapse or lateral movement resulting from hydrostatic loads, including the effects of buoyancy, during conditions of the design flood. Fully enclosed temporary structures shall have flood openings that are in accordance with ASCE 24 to allow for the automatic entry and exit of flood waters.

(2) Temporary stored materials shall not include hazardous materials.

(3) The requirements of Section 16.62.320(d) of these regulations, when located in floodways.

(d) Fences in Floodways. Fences in floodways that have the potential to block the passage of floodwaters, such as stockade fences and wire mesh fences, shall meet the limitations of Section 16.62.320(d) of these regulations.

(e) Retaining Walls, Sidewalks and Driveways in Floodways. Retaining walls and sidewalks and driveways that involve placement of fill in floodways shall meet the limitations of Section 16.62.320(d) of these regulations and the requirements for site grading in Chapter 18 of the building code.

(f) Roads and Watercourse Crossings in Floodways. Roads and watercourse crossings that encroach into floodways or riverine waterways with base flood elevations where floodways have not been designated, including roads, bridges, culverts, low-water crossings and similar means for vehicles or pedestrians to travel from one side of a watercourse to the other side shall meet the limitations of Section 16.62.320(d) of these regulations. Alteration of a watercourse that is part of work proposed for a road or watercourse crossing shall meet the requirements of Section 16.62.130(c)(3) of these regulations.

(g) Swimming Pools. Above-ground swimming pools, on-ground swimming pools, and in- ground swimming pools that involve placement of fill in floodways shall meet the requirements of Section 16.62.320(d) of these regulations. (Ord. 3220-23, 9/26/2023)

(a) Flood Control Projects; General. Where the city has regulatory jurisdiction over a flood control project, then in addition to applicable federal, state and other local permits, to the city shall examine the impact on flood hazard areas, floodways, and base flood elevations shown on the FIRM. Unless otherwise authorized by separate regulations, issuance of this approval does not address the sufficiency of the structural elements of the proposed flood control project. Approval for floodplain development and building permits in areas affected by proposed flood control projects shall not be issued based on Conditional Letters of Map Revision issued by FEMA.

(b) Flood Control Projects; Applications. Applications for approval of flood control projects shall include documentation including but not limited to:

(1) Site plan or document showing the existing topography and the boundaries of the
flood hazard areas, floodway boundaries, and base flood elevations shown on the
FIRM.

(2) Site plan or document showing the proposed topography and the proposed changes to
the boundaries of the flood hazard areas, floodway boundaries, and base flood
elevations.

(3) The documentation submitted to FEMA for a Conditional Letter of Map Revision
(CLOMR) and, if issued, the Conditional Letter of Map Revision. Submittal
requirements and processing fees shall be the responsibility of the applicant. A
CLOMR is required when a proposed flood control project alters a floodway and
increases base flood elevations greater than zero feet, or alters a watercourse a
riverine flood hazard area for which base flood elevations are included in the Flood
Insurance Study or on the FIRM and floodways have not been designated and
increases base flood elevations more than one foot.

(Ord. 3220-23, 9/26/2023)