(a) The definitions contained hereafter shall govern the interpretation of the terms defined for the purposes of this chapter, except where the context clearly requires otherwise. Words used in this chapter and not defined in this section shall be interpreted so as to give them the meaning they have in common usage and to give this chapter its most reasonable application.
(1) "Appeal" means a request for a review of the floodplain administrator's interpretation of any provision of this chapter or a request for a variance.
(2) "Area of shallow flooding" means a designated AO or AH zone on the Flood Insurance Rate Map. The base flood depths range from one to three feet; a clearly defined channel does not exist; the path of flooding is unpredictable and indeterminate; and velocity flow may be evident.
(3) "Area of Special Flood Hazard." See "Special flood hazard area."
(4) "Base flood" or "one hundred year flood" means the flood having a one percent chance of being equaled or exceeded in any given year.
(5) “Base flood elevation (BFE)” means elevation of flooding, including wave height, relative to the National Geodetic Vertical Datum (NGVD), North American Datum (NAVD) or other datum specified on the Flood Insurance Rate Map (FIRM) having a 1% chance of being equaled or exceeded in any given year.
(6) “Basement” means any area of the building having its floor subgrade (below ground level) on all sides.
(7) “Breakaway walls” means any type of walls, whether solid or lattice, and whether constructed of concrete, masonry, wood, metal, plastic or any other suitable building material which is not part of the structural support of the building and which is designed to break away under abnormally high tides or wave action without causing any damage to the structural integrity of the building on which they are used or any buildings to which they might be carried by floodwaters. A breakaway wall shall have a safe design loading resistance of not less than ten and no more than twenty pounds per square foot. Use of breakaway walls must be certified by a registered engineer or architect and shall meet the following conditions:
(A) Breakaway wall collapse shall result from a water load less than that which would occur during the base flood; and
(B) The elevated portion of the building shall not incur any structural damage due to the effects of wind and water loads acting simultaneously in the event of the base flood.
(8) “Coastal high hazard area” is the area subject to high velocity waters, including coastal and tidal and inundation or tsunamis. The area is designated on the Flood Insurance Rate Map as Zone V1 - V30, VE or V.
(9) “Design Flood Elevation (DFE)” means elevation of the design flood, including wave height, relative to the datum specified on the community's flood hazard map.
(10) “Development” means any man-made change to improved or unimproved real estate, including but not limited to buildings or other structures, mining, dredging, filling, grading, paving, excavation or drilling operations or bulk storage of equipment or materials.
(11) “Dry floodproofing” means a combination of measures that results in a structure, including the attendant utilities and equipment, being watertight with all elements substantially impermeable and with structural components having the capacity to resist flood loads.
(12) “Flood” or “Flooding” means a general and temporary condition of partial or complete inundation of normally dry land areas from (A) the overflow of floodwaters, (B) the unusual and rapid accumulation or runoff of surface waters from any source, and/or (C) the collapse or subsidence of land along the shore of a lake or other body of water as a result of erosion or undermining caused by waves or currents of water exceeding anticipated cyclical levels or suddenly caused by an unusually high water level in a natural body of water, accompanied by a severe storm, or by an unanticipated force of nature, such as flash flood or an abnormal tidal surge, or by some similarly unusual and unforeseeable event which results in flooding.
(13) “Flood Boundary and Floodway Map” means the official map on which the Federal Emergency Management Agency or Federal Insurance Administration has delineated both the areas of flood hazard and the floodway.
(14) “Flood control project” means a dam or barrier design and constructed to keep water away from or out of a specific area, including but not limited to levees, floodwalls and channelization.
(15) “Flood Insurance Rate Map” means the official map on which the Federal Emergency Management Agency or Federal Insurance Administration has delineated both the areas of special flood hazard and the risk premium zones applicable to the community.
(16) “Flood Insurance Study” means the official report provided by the Federal Insurance Administration that includes flood profiles, the Flood Insurance Rate Map, the Flood Boundary and Floodway Map, and the water surface elevation of the base flood.
(17) “Floodplain” or “flood-prone area” means any land area susceptible to being inundated by water from any flood.
(18) “Floodplain management” means the operation of an overall program of corrective and preventive measures for reducing flood damage, including but not limited to emergency preparedness plans, flood control works and floodplain management regulations.
(19) “Floodplain management regulations” means zoning ordinances, subdivision regulations, building codes, health regulations, special purpose ordinances (such as floodplain ordinance, grading ordinance and erosion control ordinance) and other applications of police power. The term describes such State of California or local regulations in any combination thereof, which provide standards for the purpose of flood damage prevention and reduction.
(20) “Floodproofing” means any combination of structural and nonstructural additions, changes or adjustments to non-residential structures which reduce or eliminate flood damage to real estate or improved real property, water and sanitary facilities, structures and their contents.
(21) “Floodway” or “regulatory floodway” means the channel of a river or other watercourse and the adjacent land areas that must be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation more than one foot.
(22) “Functionally dependent use” means a use which has an intended purpose that cannot be performed, unless it is located or carried out in close proximity to water. The term includes only docking facilities, port facilities that are necessary for the loading and unloading of cargo or passengers, and shipbuilding and ship repair facilities, but does not include long-term storage or related manufacturing facilities.
(23) “Highest adjacent grade” means the highest natural elevation of the ground surface prior to construction next to the proposed foundations of a structure.
(24) “Historic structure” means any structure that is listed individually in the National Register of Historic Places or in the State of California Register of Historical Resources or any structure that is listed individually in the current edition of the Palo Alto Master List of Structures on the Historic Inventory in Category 1 “Exceptional Building” or Category 2 “Major Building” or any structure that has been certified by the Keeper of the National Register as contributing to the historical significance of a registered historic district.
(25) “Hydrodynamic loads” means loads imposed on an object by water flowing against and around it.
(26) “Hydrostatic loads” means loads imposed on an object by standing mass of water.
(27) “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 through a Letter of Map Amendment (LOMA), Letter of Map Revision (LOMR) or Letter of Map Revision based on fill (LOMR-F).
(A) “Letter of Map Amendment (LOMA)”: An amendment based on technical data showing the 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 (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 regulation.
(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 area. 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.
(28) “Lowest floor” means the lowest floor of the lowest enclosed area, including basement.
(A) An unfinished or flood resistant enclosure below the lowest floor that is usable solely for the parking of vehicles, building access or storage in an area other than a basement area is not considered a building’s lowest floor, provided that it conforms to the applicable non-elevation design requirements, including but not limited to:
(3) The construction materials and methods standards set forth in subsection (b) of Section 16.52.130; and
(B) For residential structures, all subgrade enclosed areas are prohibited as they are considered to be basements. This prohibition includes below-grade garages, storage areas and subfloor crawl spaces, except existing below-grade subfloor crawl spaces meeting the standards set forth in subsection (d) of Section 16.52.130.
(29) “Manufactured home” means a structure, transportable in one or more sections, which is built on a permanent chassis and is designed for use with or without a permanent foundation when it is attached to the required utilities. The term does not include a recreational vehicle.
(30) “Manufactured home park or subdivision” means a parcel (or contiguous parcels) of land divided into two or more manufactured home lots for sale or rent.
(31) “Market value of the structure” means that value of a structure determined by estimating the cost to replace the structure in a new condition and adjusting that cost figure by the amount of depreciation which has accrued since the structure was constructed. The cost of replacement of the structure shall be based on a square foot cost factor determined by reference to a building cost estimating guide recognized by the building construction industry, as approved by the floodplain administrator. The amount of depreciation shall be determined by taking into account the age and physical deterioration of the structure and functional obsolescence, as approved by the floodplain administrator, but shall not include economic or other forms of external obsolescence. The use of replacement costs or accrued depreciation factors different from those contained in recognized building cost estimating guides may be approved at the discretion of the floodplain administrator only if such factors are included in a report prepared by an independent professional appraiser and supported by a written explanation of the differences.
(32) “Mean sea level” means, for purposes of the National Flood Insurance Program, the National Geodetic Vertical Datum (NGVD) of 1929 or other datum, to which base flood elevations shown on a community’s Flood Insurance Rate Map are referenced.
(33) “New construction,” for floodplain management purposes, means structures for which the “start of construction” commenced on or after the effective date of floodplain management regulations adopted by this community, and includes any subsequent improvements to such structures.
(34) “Person” means an individual or his agent, firm, partnership, association or corporation, or agent of the aforementioned groups, or the State of California or its agencies or political subdivisions.
(35) “Recreational vehicle” means a vehicle which:
(A) Is built on a single chassis;
(B) Measures 400 square feet or less at its largest or widest horizontal projection;
(C) Is designed to be self-propelled or permanently towable by a small truck;
(D) Is designed primarily not for use as a permanent dwelling but as temporary living quarters for recreational, seasonal use camping or travel; and
(E) Incorporates a vehicle that is defined by the State of California as a camp trailer, camper, fifth-wheel travel trailer, or house car.
(36) “Remedy a violation” means to bring the structure or other development into compliance with the State of California or local floodplain management regulations, or, if this is not possible, to reduce the impacts of its noncompliance. Ways that impacts may be reduced include protecting the structure or other affected development from flood damages, implementing the enforcement provisions of this chapter or otherwise deterring future similar violations, or reducing federal or State of California financial exposure with regard to the structure or other development.
(37) “Riverine” means relating to, formed by, or resembling a river (including tributaries), stream, or brook.
(38) “Sand dunes” means naturally occurring accumulations of sand in ridges or mounds landward of the beach.
(39) “Special flood hazard area (SFHA)” means an area having special flood or flood-related erosion hazards, and shown on the Flood Insurance Rate Map as Zone A, AO, Al - A30, AE, AH, V1 - V30, VE or V.
(40) “Start of construction” includes substantial improvement and other proposed new development, and means the date on which the building permit was issued, provided the actual start of construction, repair, reconstruction, rehabilitation, addition, placement, or other improvement commenced within 180 days from the date of issuance of the permit. The actual start means either the first placement of permanent construction of a structure on a site, such as the pouring of slab or footings, the installation of piles, the construction of columns, or any work beyond the stage of excavation; or the placement of a manufactured home on a foundation. Permanent construction does not include land preparation, such as clearing, grading and filling; nor does it include the installation of streets and/or walkways; nor does it include excavation for a basement, footings, piers, or foundations or the erection of temporary forms; nor does it include the installation on the property of accessory buildings, such as garages or sheds not occupied as dwelling units or not part of the main structure. For a substantial improvement, the actual start of construction means the first alteration of any wall, ceiling, floor, or other part of a structure, whether or not that alteration affects the external dimensions of the structure.
(41) “Structure” means a walled and roofed building, including but not limited to a gas or liquid storage tank, that is principally above ground, as well as a manufactured home.
(42) “Substantial damage” means damage of any origin sustained by a structure, whereby the cost of restoring the structure to its original damage-free condition would equal or exceed fifty percent of the market value of the structure before the damage occurred.
(43) “Substantial improvement” means any reconstruction, rehabilitation, addition, or other proposed new development of a structure, the cost of which equals or exceeds fifty percent of the market value of the structure before the start of construction of the improvement. This term includes a structure which has incurred substantial damage, regardless of the actual repair work to be performed.
The term shall not include:
(A) Any project, or any portion of a project, for improvement of a structure undertaken in response to a finding by the local code enforcement official that there are existing violations of State of California or local health, sanitary, or safety code specifications which render the structure unfit for human occupancy; or
(B) Any alteration of an historic structure, provided that the alteration will not result in the termination of a structure’s continued designation as an historic structure; or
(C) Any project, or any portion of a project, for improvement of a structure that is required to comply with the Americans with Disabilities Act of 1990 (42 U.S.C. Section 12101 et.seq.).
(44) “Variance” means a grant of relief from the requirements of this chapter which permits construction in a manner that would otherwise be prohibited by this chapter.
(45) “Violation” means the failure of a structure or other development to be fully compliant with the community’s floodplain management regulations. A structure or other development without the elevation certificate, other certifications, or other evidence of compliance required in this chapter is presumed to be in violation until such time as that documentation is provided.
(46) “Wet floodproofing” means a floodproofing method that relies on the use of flood damage-resistant materials and construction techniques in areas of a structure that are below the elevation required by this standard by intentionally allowing those areas to flood.
(Ord. 5566 § 3, 2022: Ord. 4824 § 1, 2004: Ord. 4557 § 2, 1999: Ord. 3795 § 2, 1988: Ord. 3158 § 1 (part), 1979)