Chapter 12.42
FLOOD DAMAGE PREVENTION
Sections:
12.42.11 Statutory authorization.
12.42.13 Statement of purpose.
12.42.14 Methods of reducing flood losses.
12.42.31 Lands to which this chapter applies.
12.42.32 Basis for establishing the areas of special flood concern.
12.42.34 Abrogation and greater restrictions.
12.42.36 Warning and disclaimer of liability.
12.42.42 Designation of the floodplain administrator.
12.42.43 Duties and responsibilities of floodplain administrator.
12.42.51 Standards of construction.
12.42.52 Standards for utilities.
12.42.53 Standards for subdivisions.
12.42.54 Standards for manufactured homes and recreational vehicles.
12.42.56 Coastal high hazard areas and coastal A zones.
12.42.61 Appeals and variances.
12.42.62 Variance conditions and requirements.
12.42.11 Statutory authorization.
The legislature of the state of California has in Government Code Sections 65302, 65560 and 65800 conferred upon local government units authority to adopt regulations designed to promote the public health, safety, and general welfare of its citizenry. (Ord. 1022 § 8 (part), 2016).
12.42.12 Findings of fact.
(a) The flood hazard areas of the city of Menlo Park are subject to periodic inundation which results in loss of life and property, health and safety hazards, disruption of commerce and governmental services, extraordinary public expenditures for flood protection and relief and impairment of the tax base, all of which adversely affect the public health, safety and general welfare.
(b) These flood losses are caused by the cumulative effect of obstructions in areas of special flood hazards which increase flood heights and velocities, and when inadequately anchored, damage uses in other areas. Uses that are inadequately floodproofed, elevated or otherwise protected from flood damage also contribute to the flood loss. (Ord. 1093 § 11, 2022; Ord. 1022 § 8 (part), 2016).
12.42.13 Statement of purpose.
It is the purpose of this chapter to promote the public health, safety, and general welfare, and to minimize public and private losses due to flood conditions in specific areas by provisions designed:
(1) To protect human life and health;
(2) To minimize expenditure of public money for costly flood control projects;
(3) To minimize the need for rescue and relief efforts associated with flooding and generally undertaken at the expense of the general public;
(4) To minimize prolonged business interruptions;
(5) To minimize damage to public facilities and utilities such as water and gas mains, electric, telephone and sewer lines, streets and bridges located in areas of special flood hazard;
(6) To help maintain a stable tax base by providing for the second use and development of areas of special flood hazard so as to minimize future flood blight areas;
(7) To insure that potential buyers are notified that property is in an area of special flood hazard; and
(8) To insure that those who occupy the areas of special flood hazard assume responsibility for their actions. (Ord. 1022 § 8 (part), 2016).
12.42.14 Methods of reducing flood losses.
In order to accomplish its purposes, this chapter includes methods and provisions for:
(1) Restricting or prohibiting uses which are dangerous to health, safety, and property due to water or erosion hazards, or which result in damaging increases in erosion or flood heights or velocities;
(2) Requiring that uses vulnerable to flood, including facilities which serve such uses, be protected against flood damage at the time of initial construction;
(3) Controlling the alteration of natural floodplains, stream channels, and natural protective barriers, which help accommodate or channel floodwaters;
(4) Controlling filling, grading, dredging, and other development which may increase flood damage; and,
(5) Preventing or regulating the construction of flood barriers which will unnaturally divert floodwaters or which may increase flood hazards in other areas. (Ord. 1022 § 8 (part), 2016).
12.42.20 Definitions.
Unless specifically defined below, words and phrases used in this chapter 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) "Accessory structure" means a structure that is either: solely for the parking of no more than two (2) cars or a small, low cost shed for limited storage, less than one hundred fifty (150) square feet and one thousand five hundred dollars ($1,500) in value.
(2) "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.
(3) "Area of shallow flooding" means a designated AO or AH zone on the flood insurance rate map (FIRM). The base flood depths range from one (1) to three (3) feet; a clearly defined channel does not exist; the path of flooding is unpredictable and indeterminate; and velocity flow may be evident. Such flooding is characterized by ponding or sheet flow.
(4) Area of Special Flood Hazard. See "special flood hazard area."
(5) "Base flood elevation (BFE)" means the elevation shown on the flood insurance rate map for zones AE, AH, A1-30, VE and V1-V30 that indicates the water surface elevation resulting from a flood that has a one percent (1%) or greater 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" are any type of walls, whether solid or lattice, and whether constructed of concrete, masonry, wood, metal, plastic or any other suitable building materials, which are not part of the structural support of the building and which are 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 (10) and no more than twenty (20) 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) Building. See "structure."
(9) "Coastal A zones" means special flood hazard areas landward of a V zone or landward of an open coast without a mapped V zone, where the principal sources of flooding are associated with astronomical tides, storm surges, seiches or tsunamis, not riverine flooding. During base flood conditions, the potential for breaking wave heights between one and one-half (1.5) feet and three (3) feet will exist.
(10) "Coastal high hazard area" means an area of special flood hazard extending from offshore to the inland limit of a primary frontal dune along an open coast and any other area subject to high velocity wave action from storms or seismic sources. It is an area subject to high velocity waters, including coastal and tidal inundation or tsunamis. The area is designated on a flood insurance rate map (FIRM) as zone V1-V30, VE, or V.
(11) "Design flood elevation (DFE)" means the elevation of the design flood, including wave height, relative to the datum specified on a community’s flood hazard map.
(12) "Development" means any manmade 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 storage of equipment or materials.
(13) "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 to the entrance of floodwater and with structural components having the capacity to resist flood loads.
(14) "Encroachment" means the advance or infringement of uses, plant growth, fill, excavation, buildings, permanent structures or development into a floodplain which may impede or alter the flow capacity of a floodplain.
(15) "Existing manufactured home park or subdivision" means a manufactured home park or subdivision for which the construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including, at a minimum, the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads) is completed before the effective date of the floodplain management regulations adopted by a community.
(16) "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).
(17) "Flood, flooding, or floodwater" 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 as defined in this definition.
(18) "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.
(19) "Flood hazard boundary map" means the official map on which the Federal Emergency Management Agency or Federal Insurance Administration has delineated the areas of flood hazards.
(20) "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 hazards and the risk premium zones applicable to the community.
(21) "Flood insurance study" means the official report provided by the Federal Insurance Administration that includes flood profiles, the FIRM, the flood boundary and floodway map, and the water surface elevation of the base flood and supporting technical data.
(22) "Floodplain or flood-prone area" means any land area susceptible to being inundated by water from any source (see definition of "flooding").
(23) "Floodplain administrator" means the community official designated by title to administer and enforce the floodplain management regulations.
(24) "Floodplain management" means the operation of an overall program of corrective and preventive measures for reducing flood damage and preserving and enhancing, where possible, natural resources in the floodplain including, but not limited to, emergency preparedness plans, flood control works and floodplain management regulations and open space plans.
(25) "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. This term describes such federal, state or local regulations, in any combination thereof, which provide standards for the purpose of flood damage prevention and reduction.
(26) "Floodproofing" means any combination of structural and nonstructural additions, changes, or adjustments to structures which reduce or eliminate flood damage to real estate or improved real property, water and sanitary facilities, structures and their contents.
(27) "Floodway" means the channel of a river or other watercourse and the adjacent land areas that must be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation more than a designated height. Also referred to as "regulatory floodway."
(28) "Floodway fringe" means that area of the floodplain on either side of the regulatory floodway where encroachment may be permitted.
(29) "Fraud and victimization," as related to Section 12.42.61, means that the variance granted must not cause fraud on or victimization of the public. In examining this requirement, the city will consider the fact that every newly constructed building adds to government responsibilities and remains a part of the community for fifty (50) to one hundred (100) years. Buildings that are permitted to be constructed below the base flood elevation are subject during all those years to increased risk of damage from floods, while future owners of the property and the community as a whole are subject to all the costs, inconvenience, danger, and suffering that those increased flood damages bring. In addition, future owners may purchase the property, unaware that it is subject to potential flood damage, and can be insured only at very high flood insurance rates.
(30) "Functionally dependent use" means a use which cannot perform its intended purpose unless it is located or carried out in close proximity to water. The term includes only docking facilities, port facilities that are necessary for the loading and unloading of cargo or passengers, and ship building and ship repair facilities, but does not include long-term storage or related manufacturing facilities.
(31) "Governing body" means the city council.
(32) "Hardship," as related to Section 12.42.61, means the exceptional hardship that would result from a failure to grant the requested variance. The city requires that the variance be exceptional, unusual, and peculiar to the property involved. Mere economic or financial hardship alone is not exceptional. Inconvenience, aesthetic considerations, physical handicaps, personal preferences, or the disapproval of one’s neighbors likewise cannot, as a rule, qualify as an exceptional hardship. All of these problems can be resolved through other means without granting a variance, even if the alternative is more expensive, or requires the property owner to build elsewhere, or put the parcel to a different use than originally intended.
(33) "Highest adjacent grade" means the highest natural elevation of the ground surface prior to construction next to the proposed walls of a structure.
(34) "Historic structure" means any structure that is:
(A) Listed individually in the National Register of Historic Places (a listing maintained by the Department of the 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 a state inventory of historic places in states with historic preservation programs which have been approved by the Secretary of the Interior; or
(D) Individually listed on a local inventory of historic places in communities with historic preservation programs that have been certified either by an approved state program as determined by the Secretary of the Interior or directly by the Secretary of the Interior in states without approved programs.
(35) "Levee" means a manmade structure, usually an earthen embankment, designed and constructed in accordance with sound engineering practices to contain, control or divert the flow of water so as to provide protection from temporary flooding.
(36) "Levee system" means a flood protection system which consists of a levee or levees, and associated structures, such as closure and drainage devices, which are constructed and operated in accord with sound engineering practices.
(37) "Lowest floor" means the lowest floor of the lowest enclosed area, including basement (see "basement" definition).
(A) An unfinished or flood resistant enclosure below the lowest floor that is usable solely for parking of vehicles, building access or storage in an area other than a basement area, is not considered a building’s lowest floor provided it conforms to applicable nonelevation design requirements, including, but not limited to:
(i) The wet floodproofing standard in Section 12.42.51(3)(D);
(ii) The anchoring standards in Section 12.42.51(1);
(iii) The construction materials and methods standards in Section 12.42.51(2);
(iv) The standards for utilities in Section 12.42.52.
(B) For residential structures, all subgrade enclosed areas are prohibited as they are considered to be basements. This prohibition includes below-grade garages and storage areas.
(Note: This definition allows attached garages to be built at grade. Below grade garages are not allowed as they are considered to be basements.)
(38) "Manufactured home" means a structure, transportable in one (1) or more sections, which is built on a permanent chassis and is designed for use with or without a permanent foundation when connected to the required utilities. For floodplain management purposes the term "manufactured home" also includes park trailers, travel trailers and other similar vehicles placed on a site for greater than one hundred eighty (180) consecutive days.
(39) "Manufactured home park or subdivision" means a parcel (or contiguous parcels) of land divided into two (2) or more manufactured home lots for sale or rent.
(40) "Market value" is defined in the city of Menlo Park’s substantial damage/improvement procedures.
(41) "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.
(42) "New construction" means, for floodplain management purposes, structures for which the "start of construction" commenced on or after the effective date of a floodplain management regulation adopted by this community and includes any subsequent improvements to such structure.
(43) "New manufactured home park or subdivision" means a manufactured home park or subdivision for which the construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including at a minimum, the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads) is completed on or after the effective date of floodplain management regulations adopted by this community.
(44) "Obstruction" includes, but is not limited to, any dam, wall, wharf, embankment, levee, dike, pile, abutment, protection, excavation, channelization, bridge, conduit, culvert, building, wire, fence, rock, gravel, refuse, fill, structure, vegetation or other material in, along, across or projecting into any watercourse which may alter, impede, retard or change the direction and/or velocity of the flow of water, or due to its location, its propensity to snare or collect debris carried by the flow of water, or its likelihood of being carried downstream.
(45) "One-hundred-year flood" or "100-year flood" means a flood which has a one percent (1%) annual probability of being equaled or exceeded in any given year. It is identical to the "base flood," which will be the term used throughout this chapter.
(46) "Person" means an individual or his agent, firm, partnership, association or corporation, or agent of the aforementioned groups, or this state or its agencies or political subdivisions.
(47) "Primary frontal dune" means a continuous or nearly continuous mound or ridge of sand with relatively steep seaward and landward slopes immediately landward and adjacent to the beach and subject to erosion and overtopping from high tides and waves during major coastal storms. The inland limit of the primary frontal dune occurs at the point where there is a distinct change from a relatively mild slope.
(48) "Public safety and nuisance," as related to Section 12.42.62, means that the granting of a variance must not result in anything 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 of use, in the customary manner, of any navigable lake, river, bay, stream, canal or basin.
(49) "Recreational vehicle" means a vehicle which is:
(A) Built on a single chassis;
(B) Four hundred (400) square feet or less when measured at the largest horizontal projection;
(C) Designed to be self-propelled or permanently towable by a light-duty truck; and
(D) Designed primarily not for use as a permanent dwelling but as temporary living quarters for recreational, camping, travel, or seasonal use.
(50) "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 (1) foot.
(51) "Remedy a violation" means to bring the structure or other development into compliance with state 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 state or federal financial exposure with regard to the structure or other development.
(52) "Riverine" means relating to, formed by, or resembling a river (including tributaries), stream, brook, etc.
(53) "Sand dunes" mean naturally occurring accumulations of sand in ridges or mounds landward of the beach.
(54) Sheet Flow Area. See "area of shallow flooding."
(55) "Special flood hazard area (SFHA)" means an area having special flood or flood related erosion hazards, and shown on an FHBM or FIRM as zone A, AO, A1-A30, AE, A99, AR, AO, AH, E, M, V1-V30, VO, VE or V.
(56) "Start of construction" includes substantial improvement and other proposed new development, and means the date the building permit was issued; provided, that the actual start of construction, repair, reconstruction, rehabilitation, addition, placement, or other improvement was within one hundred eighty (180) days of the permit date. The "actual start" means either the first placement 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 state 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 of 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 structural part of a building, whether or not that alteration affects the external dimensions of the building.
(57) "Structure" means a walled and roofed building, including a gas or liquid storage tank, that is principally above ground, as well as a manufactured home.
(58) "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.
(59) "Substantial improvement" means any repair, reconstruction, or improvement of a structure, the cost of which equals or exceeds fifty percent (50%) of the market value of the structure either:
(A) Before the improvement or repair is started; or
(B) If the structure has sustained substantial damage, any repairs are considered substantial improvement regardless of the actual repair work performed.
For the purpose of this definition "substantial improvement" is considered to occur when the first alteration of any wall, ceiling, floor, or other structural part of the building commences, whether or not that alteration affects the external dimensions of the structure. The term does not, however, include either:
(A) Any project for improvement of a structure to comply with existing state or local health, sanitary, or safety code violations identified by the building official and are the minimum necessary to assure safe living conditions; or
(B) Any alterations of a structure meeting the "historic structure" definition as defined in this section; provided, that the alteration will not preclude the structure’s continued designation as a historic structure.
(60) V Zone. See "coastal high hazard area."
(61) "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.
(62) "Violation" means the failure of a structure or other development to be fully compliant with this chapter. 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.
(63) "Water surface elevation" means the height, in relation to the North American Vertical Datum of 1988 (NAVD 88), (or other datum, where specified) of floods of various magnitudes and frequencies in the flood plains of coastal or riverline areas.
(64) "Watercourse" means a lake, river, creek, stream, wash, arroyo, channel or other topographical feature on or over which waters flow at least periodically. "Watercourse" includes specifically designated areas in which substantial flood damage may occur.
(65) "Wet floodproofing" means the use of flood-damage-resistant materials and construction techniques to minimize flood damage to areas below the flood protection level of a structure, which is intentionally allowed to flood. (Ord. 1093 § 11, 2022; Ord. 1022 § 8 (part), 2016).
12.42.31 Lands to which this chapter applies.
This chapter shall apply to all areas of special flood hazards within the jurisdiction of the city of Menlo Park. (Ord. 1022 § 8 (part), 2016).
12.42.32 Basis for establishing the areas of special flood concern.
The areas of special flood hazard identified by the Federal Insurance Administration (FIA) of the Federal Emergency Management Agency (FEMA) in the flood insurance study (FIS) dated August 4, 1980, and accompanying flood insurance rate maps (FIRMs) and flood boundary and floodway maps (FBFMs) dated February 4, 1981, and all subsequent amendments and/or revisions, are adopted by reference and declared to be a part of this chapter. This FIS and attendant mapping is the minimum area of applicability of this chapter and may be supplemented by studies for other areas which allow implementation of this chapter and which are recommended to the city by the floodplain administrator. The study, FIRMs and FBFMs are on file at the City of Menlo Park Public Works Department, 701 Laurel Street, Menlo Park, CA 94025. (Ord. 1022 § 8 (part), 2016).
12.42.33 Compliance.
No structure or land shall hereafter be constructed, located, extended, converted, or altered without full compliance with the terms of this chapter and other applicable regulations. Violations of the provisions of this chapter by failure to comply with any of its requirements including violations of conditions and safeguards established in connection with conditions shall constitute a misdemeanor. Nothing herein shall prevent the city from taking such lawful action as is necessary to prevent or remedy any violation. (Ord. 1022 § 8 (part), 2016).
12.42.34 Abrogation and greater restrictions.
This chapter is not intended to repeal, abrogate, or impair any existing easements, covenants or deed restrictions. However, where this chapter and another ordinance, easement, covenant or deed restriction conflict or overlap, whichever imposes the more stringent restrictions shall prevail. (Ord. 1022 § 8 (part), 2016).
12.42.35 Interpretation.
In the interpretation and application of this chapter, all provisions shall be:
(1) Considered as minimum requirements;
(2) Liberally construed in favor of the governing body; and
(3) Deemed neither to limit nor repeal any other powers granted under state statutes. (Ord. 1022 § 8 (part), 2016).
12.42.36 Warning and disclaimer of liability.
The degree of flood protection required by this chapter is considered reasonable for regulatory purposes and is based on scientific and engineering considerations. Large floods can and will occur on rare occasions. Flood heights may be increased by manmade or natural causes. This chapter does not imply that land outside the areas of special flood hazards, or uses permitted within such areas, will be free from flooding or flood damages. This chapter shall not create liability on the part of the city of Menlo Park, any officer or employee thereof, or the Federal Insurance Administration, for any flood damages that result from reliance on this chapter or any administrative decision lawfully made thereunder. (Ord. 1022 § 8 (part), 2016).
12.42.37 Severability.
This chapter and the various parts thereof are declared to be severable. Should any section of this chapter be declared by the courts to be unconstitutional or invalid, such decision shall not affect the validity of the chapter as a whole, or any portion thereof other than the section so declared to be unconstitutional or invalid. (Ord. 1022 § 8 (part), 2016).
12.42.41 Development permit.
(a) A development permit shall be obtained before construction or development begins within any area of special flood hazards established in Section 12.42.32. Application for a development permit shall be made on forms furnished by the floodplain administrator and may include, but not be limited to: plans in duplicate, drawn to scale, showing:
(1) Location, dimensions, and elevation of the area in question, existing or proposed structures, storage of materials and equipment and their location;
(2) Proposed locations of water supply, sanitary sewer, and other utilities;
(3) Grading information showing existing and proposed contours, any proposed fill, and drainage facilities;
(4) Location of the regulatory floodway when applicable;
(5) Base flood elevation information as specified in Section 12.42.32 or 12.42.43(3);
(6) Proposed elevation in relation to mean sea level of the lowest floor (including basement) of all structures; and
(7) Proposed elevation in relation to mean sea level to which any nonresidential structure will be floodproofed, as required in Section 12.42.51(3)(C) and detailed in FEMA Technical Bulletin TB 3-93.
(b) Certification from a registered civil engineer or architect that the nonresidential floodproofed building meets the floodproofing criteria in Section 12.42.51(3)(C).
(c) For a crawl-space foundation, location and total net area of foundation openings as required in Section 12.42.51(3)(D) and detailed in FEMA Technical Bulletins 1 and 7.
(d) Description of the extent to which any watercourse will be altered or relocated as a result of proposed development.
(e) All appropriate certifications listed in Section 12.42.43(7). (Ord. 1093 § 11, 2022; Ord. 1022 § 8 (part), 2016).
12.42.42 Designation of the floodplain administrator.
The public works director/city engineer is appointed to administer and implement this chapter by granting or denying development permits in accordance with its provisions. (Ord. 1022 § 8 (part), 2016).
12.42.43 Duties and responsibilities of floodplain administrator.
The duties and responsibilities of the floodplain administrator shall include, but not be limited to:
(1) Permit Review.
(A) Review all development permits to determine that the permit requirements of this chapter have been satisfied;
(B) All other required state and federal permits have been obtained;
(C) The site is reasonably safe from flooding;
(D) The proposed development does not adversely affect the carrying capacity of areas where base flood elevations have been determined but a floodway has not been designated. For purposes of this chapter, "adversely affects" means that the cumulative effect of the proposed development when combined with all other existing and anticipated development will increase the water surface elevation of the base flood more than one (1) foot at any point.
(E) All letters of map revision (LOMRs) for flood control projects are approved prior to the issuance of building permits. Building permits must not be issued based on conditional letters of map revision (CLOMRs). Approved CLOMRs allow construction of the proposed flood control project and land preparation as specified in the "start of construction" definition.
(2) Development of Substantial Improvement and Substantial Damage Procedures.
(A) Using FEMA publication FEMA 213, "Answers to Questions About Substantially Damaged Buildings," develop detailed procedures for identifying and administering requirements for substantial improvement and substantial damage, to include defining "market value."
(B) Assure procedures are coordinated with other departments/divisions and implemented by community staff.
(3) Review, Use, and Development of Other Base Flood Data. When base flood elevation data has not been provided in accordance with Section 12.42.32, the floodplain administrator shall obtain, review, and reasonably utilize any base flood elevation and floodway data available from a federal, state or other source, in order to administer Sections 12.42.51 through 12.42.56. Any such information shall be submitted to the city council for adoption.
Note: A base flood elevation may be obtained using one (1) of two (2) methods from the FEMA publication FEMA 265, "Managing Floodplain Development in Approximate Zone A Areas – A Guide for Obtaining and Developing Base (100-year) Flood Elevations" dated July 1995.
(4) Whenever a watercourse is to be altered or relocated:
(A) Notify adjacent communities and the California Department of Water Resources prior to such alteration or relocation of a watercourse, and submit evidence of such notification to the Federal Emergency Management Agency; and
(B) Require that the flood-carrying capacity of the altered or relocated portion of said watercourse is maintained.
(5) Base Flood Elevation Changes Due to Physical Alterations.
(A) Within six (6) months of information becoming available or project completion, whichever comes first, the floodplain administrator shall submit or assure that the permit applicant submits technical or scientific data to FEMA for a letter of map revision (LOMR).
(B) All LOMRs for flood control projects are approved prior to the issuance of building permits. Building permits must not be issued based on conditional letters of map revision (CLOMRs). Approved CLOMRs allow construction of the proposed flood control project and land preparation as specified in the "start of construction" definition. Such submissions are necessary so that upon confirmation of those physical changes affecting flooding conditions, risk premium rates and floodplain management requirements are based on current data.
(6) Changes in Corporate Boundaries. Notify FEMA in writing whenever the corporate boundaries have been modified by annexation or other means and include a copy of a map of the community clearly delineating the new corporate limits.
(7) Obtain and maintain for public inspection and make available as needed:
(A) The certification required in Section 12.42.51(3)(A) (lowest floor elevations);
(B) The certification required in Section 12.42.51(3)(C)(iii) (elevation or floodproofing of nonresidential structures);
(C) The certification required in Section 12.42.51(3)(D)(i), (ii) or (iv) (wet floodproofing standard);
(D) The certification required in Section 12.42.53(b) (subdivision standards);
(E) The certification required in Section 12.42.55(1) (floodway encroachments);
(F) Information required by Section 12.42.56 (coastal construction standards).
(8) Make interpretations where needed, as to the location of the boundaries of the areas of special flood hazards. Where there appears to be a conflict between a mapped boundary and actual field conditions, grade and base flood elevations shall be used to determine the boundaries of the special flood hazard area. The person contesting the location of the boundary shall be given a reasonable opportunity to appeal the interpretation as provided in Sections 12.42.61 and 12.42.62.
(9) Take action to remedy violations of this chapter as specified in Section 12.42.33. (Ord. 1093 § 11, 2022; Ord. 1022 § 8 (part), 2016).
12.42.51 Standards of construction.
In all areas of special flood hazards the following standards are required:
(1) Anchoring.
(A) All new construction and substantial improvements shall be anchored to prevent flotation, collapse or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy.
(B) All manufactured homes shall meet the anchoring standards of Section 12.42.54.
(2) Construction Materials and Methods.
(A) All new construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage.
(B) All new construction and substantial improvements shall be constructed using methods and practices that minimize flood damage.
(C) All new construction and substantial improvements shall be constructed with electrical, heating, ventilation, plumbing, and air conditioning equipment and other service facilities that are designed and/or located so as to prevent water from entering or accumulating within the components during conditions of flooding.
(D) All new construction and substantial improvements shall be constructed within zone AH or AO, so that there are adequate drainage paths around structures on slopes to guide floodwaters around and away from proposed structures.
(3) Elevation and Floodproofing.
(A) Residential construction (as defined by the California Residential Code as amended from time to time, i.e., single-family homes, duplex and townhomes) shall comply with the elevation requirement provisions of the California Residential Code in effect at the time of permit submittal. Other residential construction, and new or substantial improvement, shall have the lowest floor, including basement, comply with the following:
(i) In areas of shallow flooding (AO zone), elevated to a height above the highest adjacent grade of not less than the depth number specified in feet on the FIRM plus one (1) foot, or not less than three (3) feet if no depth number is specified;
(ii) In all other Zone A, including Coastal A zones, elevated to or above the base flood elevation plus one (1) foot, or the design flood elevation, whichever is higher;
(iii) In all other zones, elevated to or above the base flood elevation.
Upon the completion of the structure, the elevation of the lowest floor including basement shall be certified by a registered professional engineer or surveyor, and verified by the community building inspector to be properly elevated. Such certification and verification shall be provided to the floodplain administrator.
(B) Nonresidential new construction shall be elevated to conform with subsection (3)(A) of this section and have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy.
(C) Nonresidential substantial improvement shall either be elevated to conform with subsection (3)(A) of this section or together with attendant utility and sanitary facilities:
(i) Be dry floodproofed below the elevation required under subsection (3)(A) of this section so that the structure is watertight with walls substantially impermeable to the passage of water;
(ii) Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy; and
(iii) Be certified by registered professional engineer or architect that the standards of this subsection (3)(C) are satisfied in accordance with ASCE 24 and shall include the flood emergency plan specified in Chapter 6 of ASCE 24. Such certification shall be provided to the floodplain administrator.
(D) All new construction and substantial improvement with fully enclosed areas below the lowest floor that are usable solely for parking of vehicles, building access or storage, and which are subject to flooding shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwater. Designs for meeting this requirement shall follow the guidelines in FEMA Technical Bulletins 1, 7 and 11 as revised, amended and constructed to meet the following requirements:
(i) Be certified by a registered professional engineer or architect;
(ii) Have a minimum of two (2) openings having a total net area of not less than one (1) square inch for every square foot of enclosed area subject to flooding. The bottom of all openings shall be no higher than one (1) foot above exterior adjacent grade. Openings may be equipped with screens, louvers, valves or other coverings or devices; provided, that they permit the automatic entry and exit of floodwater;
(iii) The building must be designed and adequately anchored to resist flotation, collapse, and lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy. Crawl space construction is not allowed in areas with flood velocities greater than five (5) feet per second unless the design is reviewed by a qualified design professional, such as a registered architect or professional engineer;
(iv) The crawl space is an enclosed area below the DFE and, as such, must have openings that equalize hydrostatic pressures by allowing for the automatic entry and exit of floodwaters. For guidance on flood openings, see Technical Bulletin 1, Openings in Foundation Walls. For fully enclosed areas below the design flood elevation where provisions to allow for the automatic entry and exit of floodwaters do not meet the minimum requirements in Section 2.7.2.1 of ASCE 24, construction documents shall include a statement that the design will provide for equalization of hydrostatic flood forces in accordance with Section 2.7.2.2 of ASCE 24;
(v) Crawl space construction is not permitted in V zones. Open pile or column foundations that withstand storm surge and wave forces are required in V zones;
(vi) Portions of the building below the DFE must be constructed with materials resistant to flood damage that conform to the provisions of FEMA Technical Bulletin 2. This includes not only the foundation walls of the crawl space used to elevate the building, but also any joists, insulation, or other materials that extend below the DFE; and
(vii) Any building utility systems within the crawl space must be elevated above DFE or designed so that floodwaters cannot enter or accumulate within the system components during flood conditions.
(viii) Requirements for all below-grade crawl space construction, in addition to the above requirements, include the following provisions, per Technical Bulletin 11:
a. The interior grade of a crawl space below the DFE must not be more than two (2) feet below the lowest adjacent exterior grade (LAG), shown as D in figure 3 of Technical Bulletin 11;
b. The height of the below-grade crawl space, measured from the interior grade of the crawl space to the top of the crawl space foundation wall must not exceed four (4) feet (shown as L in figure 3 of Technical Bulletin 11) at any point;
c. There must be an adequate drainage system that removes floodwaters from the interior area of the crawl space within a reasonable period of time after a flood event;
d. The velocity of floodwaters at the site should not exceed five (5) feet per second for any crawl space. For velocities in excess of five (5) feet per second, other foundation types should be used; and
e. Below-grade crawl space construction in accordance with the requirements listed above will not be considered basements.
(E) Manufactured homes shall also meet the standards in Section 12.42.54.
(F) Accessory structures defined in Section 16.68.030 used solely for parking (two (2) car detached garages or smaller) or limited storage (low cost, not exceeding one hundred fifty (150) square feet) may be constructed such that its floor is below the design flood elevation (DFE) and not be required to apply for a variance, provided the structure is designed and constructed in accordance with the following requirements:
(i) Use of the accessory structure must be limited to parking or limited storage;
(ii) The portion of the accessory structure located below the DFE must be built using flood damage resistant materials;
(iii) The accessory structure must be adequately anchored to prevent flotation, collapse or lateral movement of the structure and meet the FEMA regulations as specified in this section;
(iv) Any mechanical and utility equipment in the accessory structure must be elevated to or above the DFE or wet-floodproofed as defined in FEMA regulations;
(v) The accessory structure must comply with floodplain encroachment provisions in FEMA Regulation 60.3(C)(10) or (d)(3); and
(vi) The accessory structure must be designed to allow for the automatic entry of floodwaters. (Ord. 1093 § 11, 2022; Ord. 1022 § 8 (part), 2016).
12.42.52 Standards for utilities.
(a) All new and replacement water supply and sanitary sewage systems shall be designed to minimize or eliminate infiltration of floodwaters into the system and discharge from systems into floodwaters.
(b) On-site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding. (Ord. 1022 § 8 (part), 2016).
12.42.53 Standards for subdivisions.
(a) All preliminary subdivision proposals shall identify the special flood hazard area and the elevation of the base flood.
(b) All final subdivision plans will provide the elevation of proposed structure(s) and pads. If the site is filled above the base flood elevation, the following as-built information for each structure shall be certified by a registered civil engineer or licensed land surveyor and provided as part of an application for a letter of map revision based on fill (LOMR-F) to the floodplain administrator:
(1) Lowest floor elevation.
(2) Pad elevation.
(3) Lowest adjacent grade.
(c) All subdivision proposals shall be consistent with the need to minimize flood damage.
(d) All subdivision proposals shall have public utilities and facilities such as sewer, gas, electrical and water systems located and constructed to minimize flood damage.
(e) All subdivisions shall provide adequate drainage to reduce exposure to flood hazards. (Ord. 1022 § 8 (part), 2016).
12.42.54 Standards for manufactured homes and recreational vehicles.
(a) All manufactured homes that are placed or substantially improved, within zones A1-30, AH, and AE on the community’s flood insurance rate map, on sites located:
(1) Outside of a manufactured home park or subdivision;
(2) In a new manufactured home park or subdivision;
(3) In an expansion to an existing manufactured home park or subdivision; or
(4) In an existing manufactured home park or subdivision on a site upon which a manufactured home has incurred substantial damage as the result of a flood; shall be elevated on a permanent foundation such that the lowest floor of the manufactured home is elevated to or above the base flood elevation and be securely fastened to an adequately anchored foundation system to resist flotation, collapse and lateral movement.
(b) All manufactured homes that are placed or substantially improved on sites located within zones V1-30, V, and VE on the community’s flood insurance rate map will meet the requirements of subsection (a) of this section and Section 12.42.56.
(c) All manufactured homes to be placed or substantially improved on sites in an existing manufactured home park or subdivision within zones A1-30, AH, AE, V1-30, V and VE on the community’s flood insurance rate map that are not subject to the provisions of subsection (a) of this section will be securely fastened to an adequately anchored foundation system to resist flotation, collapse and lateral movement, and be elevated so that either the:
(1) Lowest floor of the manufactured home is at or above the base flood elevation; or
(2) Manufactured home chassis is supported by reinforced piers or other foundation elements of at least equivalent strength that are no less than thirty-six (36) inches in height above grade.
(d) All recreational vehicles placed on sites within zones A1-30, AH and AE on the community’s flood insurance rate map will either:
(1) Be on the site for fewer than one hundred eighty (180) consecutive days, and be fully licensed and ready for highway use. A recreational vehicle is ready for highway use if it is on its wheels or jacking system, is attached to the site only by quick disconnect type utilities and security devices, and has no permanently attached additions; or
(2) Meet the permit requirements of Section 12.42.41 of this chapter and the elevation and anchoring requirements for manufactured homes in subsection (a) of this section.
(e) Recreational vehicles placed on sites within zones V1-30, V, and VE on the community’s flood insurance rate map will meet the requirements of subsection (d) of this section and Section 12.42.56.
(f) Upon the completion of the structure, the elevation of the lowest floor including basement shall be certified by a registered professional engineer or surveyor, and verified by the community building inspector to be properly elevated. Such certification and verification shall be provided to the floodplain administrator. (Ord. 1022 § 8 (part), 2016).
12.42.55 Floodways.
Located within areas of special flood hazard established in Section 12.42.32 are areas designated as floodways. Since the floodway is in an extremely hazardous area due to the velocity of floodwaters which carry debris, potential projectiles, and erosion potential, the following provisions apply:
(1) Prohibit encroachments, including fill, new construction, substantial improvements, and other development unless certification by a registered professional engineer is provided demonstrating that encroachments shall not result in any increase in flood levels during the occurrence of the base flood discharge.
(2) If subsection (1) of this section is satisfied, all new construction and substantial improvements shall comply with all other applicable flood hazard reduction provisions of Sections 12.42.51 through 12.42.56. (Ord. 1022 § 8 (part), 2016).
12.42.56 Coastal high hazard areas and coastal A zones.
Within coastal high hazard areas and coastal A zones, as established under Section 12.42.32, the following standards shall apply:
(1) Dry floodproofing of structures is not permitted in coastal high hazard areas and coastal A zones.
(2) All new construction and substantial improvement shall be elevated on adequately anchored pilings or columns and securely anchored to such pilings or columns so that the lowest horizontal portion of the structural members of the lowest floor (excluding the pilings or columns) is elevated to or above the base flood level. The pile or column foundation and structure attached thereto is anchored to resist flotation, collapse and lateral movement due to the effects of wind and water loads acting simultaneously on all building components. Water loading values used shall be those associated with the base flood. Wind loading values used shall be those required by applicable state or local building standards. Construction documents shall include a statement that the building is designed in accordance with ASCE 24.
(3) All new construction and other development shall be located on the landward side of the reach of mean high tide.
(4) All new construction and substantial improvement shall have the space below the lowest floor free of obstructions or constructed with breakaway walls in accordance with FEMA Technical Bulletins 5 and 9 as amended or revised and as defined in Section 12.42.20. Such enclosed space shall not be used for human habitation and will be usable solely for parking of vehicles, building access or storage.
(5) Fill shall not be used for structural support of buildings.
(6) Manmade alteration of sand dunes which would increase potential flood damage is prohibited.
(7) For breakaway walls designed to have a resistance of more than twenty (20) psf determined using allowable stress design, construction documents shall include a statement that the breakaway wall is designed in accordance with ASCE 24.
(8) For breakaway walls where provisions to allow for the automatic entry and exit of floodwaters do not meet the minimum requirements in Section 2.7.2.1 of ASCE 24, construction documents shall include a statement that the design will provide for equalization of hydrostatic flood forces in accordance with Section 2.7.2.2 of ASCE 24.
(9) The floodplain administrator shall obtain and maintain the following records:
(A) Certification by a registered engineer or architect that a proposed structure complies with subsection (1) of this section.
(B) The elevation (in relation to mean sea level) of the bottom of the lowest structural member of the lowest floor (excluding pilings or columns) of all new and substantially improved structures, and whether such structures contain a basement. (Ord. 1093 § 11, 2022; Ord. 1022 § 8 (part), 2016).
12.42.61 Appeals and variances.
(a) The planning commission of the city of Menlo Park shall hear and decide appeals and requests for variances from the requirements of this chapter. Decisions of the planning commission may be appealed to the city council pursuant to Chapter 16.86.
(b) The planning commission shall hear and decide appeals when it is alleged there is an error in any requirements, decision or determination made by the floodplain administrator in the enforcement or administration of this chapter. Decisions of the planning commission may be appealed to the city council pursuant to Chapter 16.86.
(c) In passing upon requests for variances or appeals from decisions of the floodplain administrator, the planning commission shall consider all technical evaluations, all relevant factors, standards specified in other sections of this chapter, and:
(1) The danger that materials may be swept onto other lands to the injury of others;
(2) The danger of life and property due to flooding or erosion damage;
(3) The susceptibility of the proposed facility and its contents to flood damage and the effect of such damage on the existing individual owner and future owners of the property;
(4) The importance of the services provided by the proposed facility to the community;
(5) The necessity to the facility of a waterfront location, where applicable;
(6) The availability of alternative locations for the proposed use which are not subject to flooding or erosion damage;
(7) The compatibility of the proposed use with existing and anticipated development;
(8) The relationship of the proposed use to the comprehensive plan and floodplain management program for that area;
(9) The safety of access to the property in time of flood for ordinary and emergency vehicles;
(10) The expected heights, velocity, duration, rate of rise and sediment transport of the floodwaters expected at the site; and
(11) The costs of providing governmental services during and after flood conditions, including maintenance and repair of public utilities and facilities such as sewer, gas, electrical, and water system, and streets and bridges.
(d) Generally, variances may be issued for new construction and substantial improvements to be erected on a lot of one-half (1/2) acre or less in size contiguous to and surrounded by lots with existing structures below the base flood level, providing subsections (c)(1) through (11) of this section have been fully considered. As the lot size increases beyond one-half (1/2) acre, the technical justification required for issuing the variance increases.
(e) Upon consideration of the factors designated in subsection (c) of this section and the purposes of this chapter, the planning commission and city council may attach such conditions to the granting of variances as it deems necessary to further the purposes of this chapter.
(f) The floodplain administrator will maintain a record of all variance actions, including justification for their issuance, and report such variances issued in its biennial report submitted to the Federal Insurance Administration, Federal Emergency Management Agency. (Ord. 1022 § 8 (part), 2016).
12.42.62 Variance conditions and requirements.
(a) Variances may be issued for the repair, rehabilitation or restoration of historic structures, as defined in Section 12.42.20, listed in the National Register of Historic Places or the State Inventory of Historic Places, upon a determination that the proposed repair, rehabilitation or restoration 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.
(b) Variances shall not be issued within any designated floodway if any increase in flood levels during the base flood discharge would result.
(c) Variances shall only be issued upon a determination that the variance is the minimum necessary, considering the flood hazard, to afford relief. "Minimum necessary" means to afford relief with a minimum of deviation from the requirements of this chapter. For example, in the case of variances to an elevation requirement, this means that the planning commission need not grant permission for the applicant to build at grade, or even to whatever elevation the applicant proposes, but only to that elevation which the planning commission believes will both provide relief and preserve the integrity of the local ordinance.
(d) Variances shall only be issued upon:
(1) A showing of good and sufficient cause;
(2) A determination that failure to grant the variance would result in exceptional hardship to the applicant;
(3) A determination that the granting of a variance will not result in increased flood heights, additional threats to public safety, extraordinary public expense, create nuisances, cause fraud on or victimization of, the public, or conflict with existing local laws or ordinances.
(e) Variances may be issued for new construction and substantial improvements and for other development necessary for the conduct of a functionally dependent use; provided, that the provisions of subsections (a) through (d) of this section are satisfied and that the structure or other development is protected by methods that minimize flood damages during the base flood and create no additional threats to public safety.
(f) Any applicant to whom a variance is granted shall be given written notice that the structure will be permitted to be built with a lowest floor elevation below the regulatory flood elevation and that the cost of flood insurance will be commensurate with the increased risk resulting from the reduced lowest floor elevation. A copy of the notice shall be recorded by the floodplain administrator in the office of the San Mateo County recorder and shall be recorded in a manner so that it appears in the chain of title of the affected parcel of land. (Ord. 1022 § 8 (part), 2016).