Chapter 7.24 FLOODPLAIN MANAGEMENT REGULATIONS

These regulations, in combination with the flood provisions of California Code of Regulations Title 24, the California Building Standards Code (hereinafter “building codes,” consisting of Part 2 (Chapter 7.32, Building Code) and Part 2 Appendix G (hereinafter “Appendix G”), Part 2.5 (Chapter 7.34, Residential Code), and Part 10 (Chapter 7.46, Existing Building Code), shall be known as the floodplain management regulations of the city of Dublin (hereinafter “these regulations”). (Ord. 13-22 § 3 (Exh. B))

7.24.020 Statutory authority.

Legislature of the state of California has, in Government Code Sections 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. (Ord. 13-22 § 3 (Exh. B))

7.24.030 Scope.

These regulations, in combination with the flood provisions of the building codes, shall apply to all proposed development in flood hazard areas established in Article II of these regulations. (Ord. 13-22 § 3 (Exh. B))

7.24.040 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:

A. Prevent unnecessary disruption of commerce, access and public service during times of flooding.

B. Manage the alteration of natural floodplains, stream channels and shorelines.

C. Manage filling, grading, dredging and other development which may increase flood damage or erosion potential.

D. Prevent or regulate the construction of flood barriers which will divert floodwater or increase flood hazards.

E. Contribute to improved construction techniques in the floodplain.

F. Minimize damage to public and private facilities and utilities.

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

H. Minimize the need for rescue and relief efforts associated with flooding.

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

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

K. Meet the requirements of the National Flood Insurance Program for community participation set forth in Title 44 Code of Federal Regulations, Section 59.22. (Ord. 13-22 § 3 (Exh. B))

7.24.050 Coordination with building codes.

Pursuant to the requirement established in state statute that the city of Dublin administer and enforce the state building codes, the City Council of the city of Dublin does hereby acknowledge 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. (Ord. 13-22 § 3 (Exh. B))

7.24.060 Adoption of CCR Title 24 Part 2 Appendix G.

CCR Title 24 Part 2 Appendix G, Flood-Resistant Construction, is hereby adopted and made a part of the California Building Standards Code and shall apply in flood hazard areas. (Ord. 13-22 § 3 (Exh. B))

7.24.070 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. (Ord. 13-22 § 3 (Exh. B))

7.24.080 Disclaimer of liability.

These regulations shall not create liability on the part of the city of Dublin, 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. (Ord. 13-22 § 3 (Exh. B))

7.24.090 Other laws.

The provisions of these regulations shall not be deemed to nullify any provisions of local, state or federal law. (Ord. 13-22 § 3 (Exh. B))

7.24.100 Abrogation and greater restrictions.

These regulations supersede any ordinance in effect in flood hazard areas. However, these regulations are not intended to repeal or abrogate any existing ordinances including land development regulations, subdivision regulations, zoning ordinances, stormwater management regulations, or building codes. In the event of a conflict between these regulations and any other ordinance, code, or regulation, the more restrictive shall govern. (Ord. 13-22 § 3 (Exh. B))

Article II. Applicability

7.24.110 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 and other developments; site improvements and installation of utilities; placement and replacement of manufactured homes; placement of recreational vehicles; new construction and alterations, repair, reconstruction, rehabilitation or additions of existing buildings and structures; substantial improvement of existing buildings and structures, including repair of substantial damage; installation of tanks; temporary structures and temporary or permanent storage; utility and miscellaneous Group U buildings and structures; and certain building work exempt from permit under the building codes; and other buildings and development activities. (Ord. 13-22 § 3 (Exh. B))

7.24.120 Establishment of flood hazard areas.

The Flood Insurance Study for Alameda County, California and Incorporated Areas, dated August 18, 1983, 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 on file at the City Hall, 100 Civic Plaza, Dublin CA, 94568. (Ord. 13-22 § 3 (Exh. B))

7.24.130 Interpretation.

In the interpretation and application of these regulations, all provisions shall be:

A. Considered as minimum requirements.

B. Liberally construed in favor of the governing body.

C. Deemed neither to limit nor repeal any other powers granted under state statutes. (Ord. 13-22 § 3 (Exh. B))

Article III. Duties and Powers of the Floodplain Administrator

7.24.140 Designation.

The Building Official is designated the Floodplain Administrator. The Floodplain Administrator shall have the authority to delegate performance of certain duties to other employees. Where Appendix G refers to the Building Official, each such reference shall refer to the Floodplain Administrator. The Floodplain Administrator is authorized and directed to administer and enforce the provisions of Appendix G. (Ord. 13-22 § 3 (Exh. B))

7.24.150 General authority.

The Floodplain Administrator is authorized and directed to administer the provisions of these regulations. The Floodplain Administrator shall have the authority to render interpretations of these regulations consistent with the intent and purpose 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 Appendix G. (Ord. 13-22 § 3 (Exh. B))

7.24.160 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 7.24.190. (Ord. 13-22 § 3 (Exh. B))

7.24.170 Duties.

The duties of the Floodplain Administrator shall include but are not limited to:

A. Review all permit applications to determine whether proposed development is located in flood hazard areas established in Article II of these regulations.

B. 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.

C. Interpret flood hazard area boundaries, provide available flood elevation and flood hazard information.

D. Determine whether additional flood hazard data shall be obtained or developed.

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

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

G. Review, in conjunction with the Building Official, required certifications and documentation specified by these regulations and the building code to determine that such certifications and documentations are complete.

H. Establish, in coordination with the Building Official, written procedures for administering and documenting determinations of substantial improvement and substantial damage made pursuant to Section 7.24.190.

I. 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.

J. 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 Appendix G.

K. 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 propose to change base flood elevations, flood hazard area boundaries, or floodway designations; such submissions shall be made within six (6) months of such data becoming available.

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

M. Inspect development within the scope of Appendix G and inspect flood hazard areas to determine if development is undertaken without issuance of permits.

N. Prepare comments and recommendations for consideration when applicants seek variances in accordance with Appendix G.

O. Cite violations.

P. Notify the Federal Emergency Management Agency when the corporate boundaries of the city of Dublin have been modified. (Ord. 13-22 § 3 (Exh. B))

7.24.180 Other permits required.

The applicant shall obtain all other required state and federal permits prior to initiating work authorized by these regulations and shall provide documentation of such permits to the Floodplain Administrator. Such permits include but are not limited to: California State Water Resources Control Board for activities that affect wetlands and alter surface water flows, in conjunction with the U.S. Army Corps of Engineers; Section 404 of the Clean Water Act. (Ord. 13-22 § 3 (Exh. B))

7.24.190 Substantial improvement and substantial damage determinations.

For applications for building permits to improve buildings and structures, including alterations, movement, 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:

A. Estimate the market value or require the applicant to obtain a professional appraisal, prepared by a qualified independent appraiser, of the market value 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.

B. 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, where applicable, to the market value of the building or structure.

C. Determine and document whether the proposed work constitutes substantial improvement or repair of substantial damage; for proposed work to repair damage caused by flooding, the determination requires evaluation of previous permits issued to repair flood-related damage as specified in the definition of “substantial damage.” The substantial improvement determination requires evaluation of previous permits issued for improvements and repairs as specified in the definition of “substantial improvement.”

D. 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. (Ord. 13-22 § 3 (Exh. B))

7.24.200 Department records.

In addition to the requirements of the building code and Appendix G, 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; 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. 13-22 § 3 (Exh. B))

Article IV. Site Plans and Documentation

7.24.210 Additional site plan information.

In addition to the site plan requirements of the building code and Appendix G, additional site plan information shall include, as applicable to the proposed development:

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

B. Location, extent, amount, and proposed final grades of any filling, grading, or excavation.

C. 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.

D. Existing and proposed alignment of any proposed alteration of a watercourse.

E. A nonconversion agreement signed by the applicant if the building in a flood hazard area has enclosed areas below the lowest floor. (Ord. 13-22 § 3 (Exh. B))

7.24.220 Additional engineering data.

When additional hydrologic, hydraulic or other engineering data, studies, and additional data and 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 registered professional 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. 13-22 § 3 (Exh. B))

7.24.230 Additional submittal requirements.

For projects proposing to enclose areas under elevated buildings, include a signed Nonconversion Agreement (Declaration of Land Restriction) which shall be recorded on the property prior to issuance of the certificate of occupancy. (Ord. 13-22 § 3 (Exh. B))

7.24.240 Information in flood hazard areas without base flood elevations (approximate Zone A).

Where flood hazard areas are delineated on the FIRM and base flood elevations data have not been provided, the Floodplain Administrator is authorized to:

A. Require the applicant to include base flood elevation data prepared by a qualified professional engineer in accordance with currently accepted engineering practices. Such analyses shall be performed and sealed by a qualified professional 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.

B. 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.

C. 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, require the applicant to include base flood elevation data in accordance with subsection A of this section.

D. 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 professional 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. (Ord. 13-22 § 3 (Exh. B))

Article V. Variances

7.24.250 Variances—In addition.

In addition to the variance provisions of Appendix G:

A. The considerations and conditions for variances set forth in Appendix G 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.

B. 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. (Ord. 13-22 § 3 (Exh. B))

7.24.260 Agricultural structures.

A variance is authorized to be issued for the construction or substantial improvement of agricultural structures that are not elevated or dry floodproofed, provided the requirements of this section are satisfied and:

A. A determination has been made that the proposed agricultural structure:

1. Is used exclusively in connection with the production, harvesting, storage, raising, or drying of agricultural commodities and livestock, or storage of tools or equipment used in connection with these purposes or uses, and will be restricted to such exclusive uses.

2. Has low damage potential.

3. Does not increase risks and pose a danger to public health, safety, and welfare if flooded and contents are released, including but not limited to the effects of flooding on manure storage, livestock confinement operations, liquefied natural gas terminals, and production and storage of highly volatile, toxic, or water-reactive materials.

4. Complies with the wet floodproofing construction requirements of subsection B of this section.

B. Wet Floodproofing Construction Requirements.

1. Anchored to resist flotation, collapse, and lateral movement.

2. When enclosed by walls, walls have flood openings that comply with the flood opening requirements of ASCE 24, Chapter 2.

3. Flood damage-resistant materials are used below the base flood elevation.

4. Mechanical, electrical, and utility equipment are elevated above the base flood elevation. (Ord. 13-22 § 3 (Exh. B))

Article VI. Violations

7.24.270 Violations—General.

In addition to the violation provisions of the building code and Appendix G, 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. (Ord. 13-22 § 3 (Exh. B))

7.24.280 Buildings and structures.

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. (Ord. 13-22 § 3 (Exh. B))

7.24.290 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. (Ord. 13-22 § 3 (Exh. B))

7.24.300 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 by Chapters 1.04 and/or 1.06. (Ord. 13-22 § 3 (Exh. B))

Part II. Definitions

Article VII. Definitions

7.24.310 General.

The following words and terms shall, for the purposes of these regulations, have the meanings shown herein. Other terms are defined in the building code and Appendix G and terms are defined where used in the Residential Code (rather than in the definitions section). Where terms are not defined, such terms shall have ordinarily accepted meanings such as the context implies. (Ord. 13-22 § 3 (Exh. B))

7.24.320 Definitions.

“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.

“Agricultural structure” means a walled and roofed structure used exclusively for agricultural purposes or uses in connection with the production, harvesting, storage, raising, or drying of agricultural commodities and livestock, including aquatic organisms. Structures that house tools or equipment used in connection with these purposes or uses are also considered to have agricultural purposes or uses.

“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.

“Development” means any manmade change to improved or unimproved real estate, including, but not limited to, buildings or other structures, tanks, temporary structures, temporary or permanent storage of materials, mining, dredging, filling, grading, paving, excavations, drilling operations and other land-disturbing activities.

“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.

“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.

“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 April 15, 1981.

“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).

“Flood control project” means a dam or barrier designed and constructed to keep water away from or out of a specified area, including but not limited to levees, floodwalls, and channelization.

“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.

“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:

1. 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.

2. 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.

3. 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.

4. 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.

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

1. Designed primarily for purposes of transportation of property or is a derivation of such a vehicle; or

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

3. Available with special features enabling off-street or off-highway operation and use.

“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 shall be determined 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) established by a qualified independent appraiser.

“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 April 15, 1981.

“Nonconversion Agreement (Declaration of Land Restriction)” means a form provided by the Floodplain Administrator to be signed by the property owner(s) and recorded with the Alameda County Clerk-Recorder’s Office, restricting the owner(s) ability to convert or modify enclosures below elevated buildings in any manner that is inconsistent with the terms of the building permit and these regulations, enclosures below elevated buildings.

“Nuisance” means that which is injurious to the 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, river, bay, stream, canal, or basin.

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

“Sand dunes” means naturally occurring accumulations of sand in ridges or mounds landward of the beach.

“Substantial damage” means damage of any origin sustained by a structure whereby the cost of restoring the structure to its before-damaged condition would equal or exceed fifty percent (50%) of the market value of the structure before the damage occurred. The term also includes flood-related damage sustained by a structure on two (2) separate occasions during a ten (10) year period for which the cost of repairs at the time of each such flood event, on average, equals or exceeds twenty-five percent (25%) of the market value of the structure before the damage occurred.

“Substantial improvement” means any combination of repair, reconstruction, rehabilitation, alteration, addition or other improvement of a building or structure, taking place during a ten (10) year period, the cumulative cost of which equals or exceeds fifty percent (50%) of the market value of the structure before the improvement or repair is started. The period of accumulation begins when the first improvement or repair of each building is permitted subsequent to January 1, 2023. 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:

1. 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.

2. Any alteration of a historic structure; provided, that the alteration will not preclude the structure’s continued designation as a historic structure.

“Watercourse” means a river, creek, stream, channel, or other topographic feature in, on, through, or over which water flows at least periodically. (Ord. 13-22 § 3 (Exh. B))

Part III. Flood Resistant Development

Article VIII. Subdivisions

7.24.330 Subdivisions—In addition.

In addition to the subdivision provisions in Appendix G, the following requirements apply:

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

B. When 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. 13-22 § 3 (Exh. B))

Article IX. Site Improvement

7.24.340 Site improvement—In addition.

In addition to the site improvement provisions in Appendix G, the requirements of this article shall apply. (Ord. 13-22 § 3 (Exh. B))

7.24.350 Limitations on placement of fill.

Where the placement of fill is permitted by the building code, Appendix G, or 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 7.24.220. (Ord. 13-22 § 3 (Exh. B))

Article X. Manufactured Homes

7.24.360 Installation—In addition.

In addition to the provisions for manufactured homes in Appendix G:

A. 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.

B. In addition to permits pursuant to Appendix G, permits from the HCD are required where the HCD is the enforcement agency for installation of manufactured homes.

C. 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. (Ord. 13-22 § 3 (Exh. B))

7.24.370 Elevation requirement for certain existing manufactured home parks and subdivisions.

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 either the:

A. 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.

B. Bottom of the frame is supported by reinforced piers or other foundation elements of at least equivalent strength that are not less than thirty-six (36) inches in height above grade. (Ord. 13-22 § 3 (Exh. B))

Article XI. Accessory Structures

7.24.380 Detached garages and accessory storage structures.

The provision in Appendix G for garages and accessory structures shall be replaced with this section. 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:

A. Are one (1) story and not larger than six hundred (600) square feet in area when located in special flood hazard areas other than coastal high hazard areas.

B. Are anchored to resist flotation, collapse or lateral movement resulting from flood loads.

C. Have flood openings in accordance with the building code.

D. Have flood damage-resistant materials used below the base flood elevation.

E. Have mechanical, plumbing and electrical systems, including plumbing fixtures, elevated to or above the base flood elevation. (Ord. 13-22 § 3 (Exh. B))

Article XII. Flood Control Projects

7.24.390 Flood control projects—General.

In addition to applicable federal, state and other local permits, a permit for floodplain development is required for construction of flood control projects. The purpose for the permit is to 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 permit does not address the sufficiency of the structural elements of the proposed flood control project. Permits 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. (Ord. 13-22 § 3 (Exh. B))

7.24.400 Flood control projects—Applications.

Applications for permits for flood control projects shall include documentation including but not limited to:

A. 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.

B. 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.

C. 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 more than zero (0.00) 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 (1.0) foot. (Ord. 13-22 § 3 (Exh. B))