Rancho Santa Margarita Municipal Code Ch. 10.11 Floodplain Management Regulations for Properties in Designated Zones

The Legislature of the State of California has in Government Code Sections 65302, 66560, and 65800 conferred upon local government units authority to adopt regulations designed to promote the public health, safety, and general welfare of its citizenry. Therefore, the City Council of the City of Rancho Santa Margarita does hereby adopt the following floodplain management regulations.

(Ord. No. 01-06, § 1(3.20.010), 6-21-2001)

(a) The flood hazard areas of the City may be subject to periodic inundation which could result 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 uses being inadequately elevated, floodproofed, or protected from flood damage. The cumulative effects of obstructions in areas of special flood hazards, which increase flood heights and velocities, also contribute to the flood loss.

(Ord. No. 01-06, § 1(3.20.020), 6-21-2001)

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 to:

(1) Protect human life and health;

(2) Minimize expenditure of public money for costly flood control projects;

(3) Minimize the need for rescue and relief efforts associated with flooding and generally undertaken at the expense of the general public;

(4) Minimize prolonged business interruptions;

(5) Minimize damage to public facilities and utilities such as water and gas mains; electric, telephone and sewer lines; and streets and bridges located in areas of special flood hazard;

(6) Help maintain a stable tax base by providing for the sound use and development of areas of special flood hazard so as to minimize future blighted areas caused by flood damage;

(7) Ensure that potential buyers are notified that property is in an area of special flood hazard; and

(8) Ensure that those who occupy the areas of special flood hazard assume responsibility for their actions.

(Ord. No. 01-06, § 1(3.20.030), 6-21-2001)

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

(1) Restrict or prohibit 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) Require that uses vulnerable to floods, including facilities which serve such uses, be protected against flood damage at the time of initial construction;

(3) Control the alteration of natural floodplains, stream channels, and natural protective barriers, which help accommodate or channel flood waters;

(4) Control filling, grading, dredging, and other development which may increase flood damage; and

(5) Prevent or regulate the construction of flood barriers which will unnaturally divert floodwaters or which may increase flood hazards in other areas.

(Ord. No. 01-06, § 1(3.20.040), 6-21-2001)

Unless specifically defined below, words or 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.

Accessory use means a use, which is incidental and subordinate to the principal use of the parcel of land on which it is located.

Alluvial fan means a geomorphologic feature characterized by a cone or fan-shaped deposit of boulders, gravel, and five sediments that have been eroded from mountain slopes, transported by flood flows, and then deposited on the valley floors, and which is subject to flash flooding, high velocity flows, debris flows, erosion, sediment movement and deposition, and channel migration.

Apex means the point of highest elevation on an alluvial fan, which on undisturbed fans is generally the point where the major stream that formed the fan emerges from the mountain front.

Appeal means a request for a review of the Floodplain Administrators interpretation of any provision of this chapter.

AR Zone means a special flood hazard area that results from the decertification of a previously accredited flood protection system that is determined to be in the process of being restored to provide a 100-year or greater level of flood protection.

Area of shallow flooding means a designated AO, AH, AR/AO, or AR/AH Zone on the Flood Insurance Rate Map (FIRM). 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. Such flow is characterized by ponding or sheet flow.

Area of special flood hazard. (See "special flood hazard area").

Base flood means a flood, which has a one percent chance of being equaled or exceeded in any given year (also called the "100 year flood"). Base flood is the term used throughout this chapter.

Basement means any area of the building having its floor subgrade, i.e., below ground level, on all sides.

Building. (See "structure").

City means the City of Rancho Santa Margarita.

Developed areas means an area of a community that is:

(1) A primarily urbanized, built-up area that is a minimum of 20 contiguous acres, has basic urban infrastructure, including roads, utilities, communications, and public facilities, to sustain industrial, residential, and commercial activities; and

a. Within which 75 percent or more of the parcels, tracts, or lots contain commercial, industrial, or residential structures of uses;

b. Is a single parcel, tract, or lot in which 75 percent of the area contains commercial or industrial structures or uses; or

c. Is a subdivision developed at a density of at least two residential structures per acre within which 75 percent or more of the lots contain existing residential structures.

(2) Undeveloped parcels, tracts, or lots, the combination of which is less than 20 and contiguous on at least three sides to areas meeting the criteria of subsection (1).

(3) A subdivision that is a minimum of 20 contiguous acres that has obtained all necessary government approvals, provided that the actual "start of construction" of structures has occurred on at least:

a. Tem percent of the lots or remaining lots of a subdivision; or

b. Ten percent of the maximum building coverage or remaining building coverage allowed for a single lot subdivision and construction of structures is underway. Residential subdivisions must meet the density criteria in subsection (1)c.

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.

Encroachment means the advance or infringement of uses, plant growth, fill, excavation, buildings, permanent structures or development into a floodplain, which may impede or after the flow capacity of a floodplain.

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.

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 Boundary and Floodway Map (FBFM) 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 floodway.

Flood, flooding or floodwater means:

(1) A general and temporary condition of partial or complete inundation of normally dry land areas from the overflow of inland or tidal waters: the unusual and rapid accumulation or runoff of surface waters from any source; and/or mudslides (i.e., mudflows); and

(2) The condition resulting from flood related erosion.

Flood Insurance Rate Map (FIRM) 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.

Flood Insurance Study means the official report provided by the Federal Insurance Administration that includes flood profiles, the Flood Insurance Rate Map, and the water surface elevation of the base flood.

Floodplain or floodprone area means any land area susceptible to being inundated by water from any source (see "flooding").

Floodplain Administrator is the individual appointed to administer and enforce the floodplain management regulations.

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, floodplain management regulations, and open space plans.

Floodplain management regulations mean this chapter and other zoning ordinances, subdivision regulations, building codes, health regulations, special purpose ordinances (such as grading and erosion control) and other application of police power which control development in floodprone areas. This term describes federal, state or local regulations in any combination thereof, which provide standards for preventing and reducing flood loss and damage.

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.

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. Also referred to as "regulatory floodway."

Floodway fringe means the area of the floodplain on either side of the "regulatory floodway" where encroachment may be permitted.

Fraud and Victimization, as related to Section 10.11.240, [nature of] variances, of this chapter, 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 50 to 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.

Governing body is the local governing unit, i.e., the City Council of the City, that is empowered to adopt and implement regulations to provide for the public health, safety and general welfare of its citizenry.

Hardship as related to Section 10.11.240, [nature of] variances, of this chapter 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.

Highest adjacent grade means the highest natural elevation of the ground surface prior to construction next to the proposed walls of a structure.

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.

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.

Lowest floor means the lowest floor of the lowest enclosed area, including basement (see "basement").

(1) 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 non-elevation design requirements, including, but not limited to:

a. The wet floodproofing standard in subsection 10.11.170(3).

b. The anchoring standards in subsection 10.11.170(1).

c. The construction materials and methods standards in subsection 10.11.170(2).

d. The standards for utilities in Section 10.11.180.

(2) For residential structures, all subgrade-enclosed areas are prohibited as they are considered to be basements (see "basement" definition). This prohibition includes below-grade garages and storage areas.

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 attached to the required utilities. The term "manufactured home" does not include a "recreational vehicle."

Manufactured home park or subdivision means a parcel (or contiguous parcels) of land divided into two or more manufactured home lots for rent or sale.

Market value shall be determined by estimating the cost to replace the structure in 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. 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 foodplain administrator, but shall not include economic or other forms of external obsolescence. Use of replacement costs or accrued depreciation factors different from those contained in recognized building cost estimating guides may be considered only if such factors are included in a report prepared by an independent professional appraiser and supported by a written explanation of the differences.

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.

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.

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.

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 carded downstream.

One hundred-year flood or 100-year flood. (See "base flood").

Public safety and nuisance as related to Section 10.11.240, [nature of] variances, of this chapter means that the granting of a variance shall 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 or use in the customary manner, of any navigable lake, or river, bay, stream, canal, or basin.

Recreational vehicle means a vehicle which is:

(1) Built on a single chassis;

(2) Four hundred square feet or less when measured at the largest horizontal projection;

(3) Designated to be self-propelled or permanently towable by a light-duty truck; and

(4) Designed primarily not for use as a permanent dwelling, but as temporary living quarters for recreational camping, travel, or seasonal use.

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.

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 the ordinance or otherwise deterring future similar violations, or reducing state or federal financial exposure with regard to the structure or other development.

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

Special flood hazard area (SFHA) means an area in the floodplain subject to a one percent or greater chance of flooding in any given year. It is shown on the FIRM as Zone A, AO, A1-30, AE, A99, AR, AR/A1-A30, AR/AE, AR/AO, AR/AH, AR/A, or AH.

Start of construction includes proposed new development and means the date the building permit was issued, provided the actual start of construction was within 180 days from the date 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 manufacture 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 structural part of a building, whether or not that alteration affects the external dimensions of the building.

Structure means a walled and roofed building that is principally above ground; this includes a gas or liquid storage tank or a manufactured home.

Substantial damage means damage of any origin sustained by a structure whereby the cost of restoring the structure to its before damaged condition would equal or exceed 50 percent of the market value of the structure before the damage occurred.

Substantial improvement means any reconstruction, rehabilitation, addition, or other proposed new development of a structure, the cost of which equals or exceeds 50 percent of the market value of the structure before the "start of construction" of the improvement. This term includes structures, which have incurred "substantial damage," regardless of the actual repair work performed. The term does not however, include:

(1) Any project for improvement of a structure to correct existing violations or state of local health, sanitary, or safety code specifications which have been identified by the local code enforcement official and which are the minimum necessary to assure safe living conditions.

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.

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.

Water surface elevation means the height, in relation to the National Geodetic Vertical Datum (NGVD) of 1929, (or other datum, where specified) of flood various magnitudes and frequencies in the floodplains of coastal or riverine areas.

Watercourse means a lake, river, creek, stream, wash, arroyo, channel or other topographic feature on or over which waters flow at least periodically. Watercourse includes specifically designated areas in which substantial flood damage may occur.

(Ord. No. 01-06, § 1(3.20.050), 6-21-2001)

This chapter shall apply to all areas of special flood hazards within the jurisdiction of the City.

(Ord. No. 01-06, § 1(3.20.060), 6-21-2001)

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 July 6, 1998 and accompanying Flood Insurance Rate Maps (FIRMS) and Flood Boundary and Floodway Maps (FBFMs) dated July 6, 1998, and all subsequent amendments and/or revisions, are hereby 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 office of the City Clerk and Engineering Department at City Hall located at 30211 Avenida de las Banderas, Suite 101, Rancho Santa Margarita, CA 92688.

(Ord. No. 01-06, § 1(3.20.070), 6-21-2001)

No structure or land shall hereafter be constructed, located, extended, converted, or altered without full compliance with the term of this chapter and other applicable regulations. Violation of the 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. No. 01-06, § 1(3.20.080), 6-21-2001)

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. No. 01-06, § 1(3.20.090), 6-21-2001)

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. No. 01-06, § 1(3.20.100), 6-21-2001)

The degree of flood protection required by this chapter is considered reasonable for regulatory purposes and is based on scientific and engineering considerations. Larger floods can and will occur on rare occasions. Flood heights maybe 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, any officer or employee thereof, the State of California, or the Federal Insurance Administration, Federal Emergency Management Agency, for any flood damages that result from reliance on this chapter or any administrative decision lawfully made hereunder.

(Ord. No. 01-06, § 1(3.20.110), 6-21-2001)

This chapter and the various parts thereof are hereby 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 ordinance as a whole, or any portion thereof other than the section so declared to be unconstitutional or invalid.

(Ord. No. 01-06, § 1(3.20.120), 6-21-2001)

A development permit shall be obtained before any construction or other development begins within any area of special flood hazard established in Section 10.11.070. 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 the nature, location, dimensions, and elevation of the area in question; existing or proposed structures, fill, storage of materials, drainage facilities; and the location of the foregoing. Specifically, the following information is required:

(1) Site plan, including but not limited to:

a. For all proposed structures, spot ground elevations at building corners and 20-foot or smaller intervals along the foundation footprint, or one foot contour elevations throughout the building site;

b. Proposed locations of water supply, sanitary sewer, and utilities;

c. If available, the base flood elevation from the Flood Insurance Study and/or Flood Insurance Rate Map; and

d. If applicable, the location of the regulatory floodway; and

(2) Foundation design detail, including but not limited to:

a. Proposed elevation in relation to mean sea level, of the lowest floor (including basement) of all structures;

b. For a crawl-space foundation, location and total net area of foundation openings as required in Section 10.11.170 of this chapter and FEMA Technical Bulletins 1-93 and 7-93; and

c. For foundations placed on fill, the location and height of fill, and compaction requirements (compacted to 95 percent using the Standard Proctor Test method); and

(3) Proposed elevation in relation to mean sea level to which any nonresidential structure will be floodproofed, as required in Section 10.11.170 of this chapter and FEMA Technical Bulletin TB 3-93; and

(4) All appropriate certifications listed in Section 10.11.150 of this chapter; and

(5) Description of the extent to which any watercourse will be altered or relocated as a result of proposed development.

(Ord. No. 01-06, § 1(3.20.130), 6-21-2001)

The City Council shall designate the Floodplain Administrator by resolution.

(Ord. No. 01-06, § 1(3.20.140), 6-21-2001)

The duties and responsibilities of the Floodplain Administrator shall include but not be limited to the following:

(1) Permit review. Review all development permits to determine that:

a. 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; and

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 foot at any point.

(2) Review and use of any other base flood data. When base flood elevation data has not been provided in accordance with Section 10.11.070, the Floodplain Administrator shall obtain, review, and reasonably utilize any base flood elevation and floodway data available from a federal to state agency, or other source, in order to administer Section 10.11.170 et seq. Any such information shall be submitted to the City Council for adoption; or

a. If no base flood elevation data is available from a federal or state agency or other source, then a base flood elevation shall be obtained using one of two methods from the FEMA publication "Managing Floodplain Development in Approximate Zone A Areas - A Guide for Obtaining and Developing Base (100-year) Flood Elevations" dated July 1995 in order to administer Section 10.11.170 et seq.

1. Simplified method.

i. One hundred year or base flood discharge shall be obtained using the appropriate regression equation found in a U.S. Geological Survey publication, or the discharge-drainage area method; and

ii. Base flood elevation shall be obtained using the Quick-2 computer program developed by FEMA; or

2. Detailed method.

i. One hundred year or base flood discharge shall be obtained using the U.S. Army Corps of Engineers' HEC-HMS computer program; and

ii. Base flood elevation shall be obtained using the U.S. Army Corps of Engineers' HEC-RAS computer program.

(3) Notification of other agencies. In alteration or relocation of a watercourse:

a. Notify adjacent communities and the California Department of Water Resources prior to alteration or relocation;

b. Submit evidence of such notification to the Federal Insurance Administration, Federal Emergency Management Agency; and

c. Assure that the flood carrying capacity within the altered or relocated portion of said watercourse is maintained.

(4) Documentation of floodplain development. Obtain and maintain for public inspection and make available, as needed the following:

a. Certification required by subsection 10.11.170(3)a. (lowest floor elevations),

b. Certification required by subsection 10.11.170(3)b. (elevation or floodproofing of non-residential structures),

c. Certification required by subsection 10.11.170(3)c. (wet floodproofing standard),

d. Certification of elevation required by subsection 10.11.190(b) (subdivision standards), and

(5) Map determinations. Make interpretations where needed, as to the exact location of the boundaries of the areas of special flood hazard, for example, 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.

(6) Remedial action. Take action to remedy violations of this chapter as specified in Section 10.11.090.

(7) AR Zone Duties.

a. Use the adopted official map or legal description of those designated developed areas within Zones AR, AR/AR1-30, AR/AE, AR/AH, AR/A, AR/AO, to determine if a proposed project is in a developed area.

b. Determine the base flood elevation to be used for individual projects within developed areas, areas not designated as developed areas, and dual zone areas.

c. Require the applicable standards in Sections 10.11.170 et seq.

d. Provide written notification to the permit applicant that the area has been designated as an AR, AR/A1-30, AR/AE, AR/AH, AR/AO, or AR/A Zone and whether the structure will be elevated or protected to or above the AR base flood elevation.

(Ord. No. 01-06, § 1(3.20.150), 6-21-2001)

The City Council of the City shall hear and decide appeals when it is alleged there is an error in any requirement, decision, or determination made by the Floodplain Administrator in the enforcement or administration of this chapter.

(Ord. No. 01-06, § 1(3.20.160), 6-21-2001)

In all areas of special flood hazards the following standards are required:

(1) Anchoring.

a. All new construction shall be adequately 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 10.11.200.

(2) Construction materials and methods. All new construction and substantial improvement shall be constructed:

a. With flood resistant materials as specified in FEMA Technical Bulletin TB 2-93, and utility equipment resistant to flood damage;

b. Using methods and practices that minimize flood damage;

c. 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; and if

d. Within Zones AH, AO, AR/AH, or AR/AO, so that there are adequate drainage paths around structures on slopes to guide floodwaters around and away from the proposed structures.

(3) Elevation and flood proofing.

a. Residential construction, new or substantial improvement, shall have the lowest floor, including basement,

1. In an AO Zone, elevated above the highest adjacent grade to a height equal to or exceeding the depth number specified in feet on the FIRM, or elevated at least two feet above the highest adjacent grad if no depth number is specified. (The State of California recommends that in AO Zones without velocity the lowest floor be elevated above the highest adjacent grade to a height exceeding the depth number specified in feet on the FIRM by at least two feet, or elevated at least four feet above the highest adjacent grade if no depth number is specified.)

2. In an A Zone, elevated to or above the base flood elevation; said base flood elevation shall be determined by one of the methods in Section 10.11.150 of this chapter. (The State of California recommends the lowest floor be elevated at least two feet above the base flood elevation, as determined by the community.)

3. In all other Zones, elevated to or above the base flood elevation. (The State of California recommends the lowest floor be elevated at least two feet 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. Non-residential construction, new or substantial improvement, shall either be elevated to conform with subsection 10.11.170(3)a. or together with attendant utility and sanitary facilities;

1. Be floodproofed below the elevation recommended under subsection 10.11.170(3)a. so that the structure is watertight with walls substantially impermeable to the passage of water;

2. Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy; and

3. Be certified by a registered professional engineer or architect that the standards of this section are satisfied. Such certification shall be provided to the Floodplain Administrator.

c. All new construction and substantial improvements with fully enclosed areas below the lowest floor (excluding basements) 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 TB 1-93 and TB 7-93, and must exceed the following minimum criteria:

1. Have a minimum of two openings having a total net area of not less than one square inch for every square foot of enclosed area subject to flooding. The bottom of all openings shall be no higher than one foot above 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; or

2. Be certified by a registered professional engineer or architect.

d. Manufactured homes shall also meet the standards in Section 10.11.200.

(Ord. No. 01-06, § 1(3.20.170), 6-21-2001)

(a) All water supply and sanitary sewage systems shall be designed to minimize or eliminate:

(1) Infiltration of flood waters into the systems; and

(2) Discharge from the systems into floodwaters.

(b) On site waste disposal systems to new construction shall be located to avoid impairment to them, or contamination from them during flooding.

(Ord. No. 01-06, § 1(3.20.180), 6-21-2001)

(a) All preliminary subdivision proposals shall identify the special flood hazard area and the elevation of the base flood.

(b) All subdivision plans shall provide the elevation of proposed structure(s) and pad(s). If the site is filled above the base flood elevation, the lowest floor and pad elevations shall be certified by a registered professional engineer or surveyor and provided to the Floodplain Administrator.

(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. No. 01-06, § 1(3.20.190), 6-21-2001)

(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 2 site upon which a manufactured home has incurred "substantial damage" as the result of a flood, shall be elevated an 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 to be placed or substantially improved on sites in an existing manufactured home park or subdivision within Zones A1-30, AH, AE on the community Flood Insurance Rate Map that are not subject to the provisions of subsection 10.11.200(a) will be securely fastened to an adequately anchored foundation system to resist flotation collapse and lateral movement, and be elevated so either the:

(1) Lowest floor of the manufactured home is at or above the base flood; or

(2) Manufactured home chassis is supported by reinforced piers or other foundation elements of at least equivalent strength that are no less than 36 inches in height above grade.

(3) Upon the completion of the structure, the elevation of the lowest floor including basement shall be certified if a registered professional engineer or surveyor, and verified by the building inspector to be properly elevated. Such certification and verification shall be provided to the Floodplain Administrator.

(Ord. No. 01-06, § 1(3.20.200), 6-21-2001)

(a) 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 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 wheals 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 10.11.150 et seq. of this chapter and the elevation and anchoring requirements for manufactured homes in subsection 10.11.200(a).

(Ord. No. 01-06, § 1(3.20.210), 6-21-2001)

Located within areas of special flood hazard established in Section 10.11.070 are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of floodwaters, which carry debris, potential projectiles, and erosion potential, the following provisions apply.

(1) Prohibit encroachments, including fill, new construction, substantial improvement, and other new development unless certification by a registered professional engineer is provided demonstrating that encroachments shall not result in any increase in the base flood elevation during the occurrence of the base flood discharge.

(2) If subsection 10.11.220(1) is satisfied, all new construction, substantial improvement, and other proposed new development shall comply with all other applicable flood hazard reduction provisions of Section 10.11.170.

(Ord. No. 01-06, § 1(3.20.220), 6-21-2001)

Within areas designated as AR, AR/A1-30, AR/AE, AR/AH, AR/AO or AR/A as established under Section 10.11.070, the following standards shall apply:

(1) Developed areas. All new construction in areas designated as developed areas shall meet the standards of Section 10.11.170 using the lower of either the AR base flood elevation or the elevation that is three feet above the highest adjacent grade.

(2) Areas not designated as developed areas. All new construction in areas that are not designated as developed areas:

a. Where the AR flood depth is equal to or less than five feet above the highest adjacent grade, shall meet the standards of Section 10.11.170 using the lower of either the AR base flood elevation or the elevation that is 13 feet above the highest adjacent grade; or

b. Where the AR flood depth is greater than five feet above the highest adjacent grade, shall meet the standards of Section 10.11.170 using the AR base flood elevation.

(3) Dual zone areas.

a. All new construction in areas within Zone AR/A1-30, AR/AE, AR/AH, AR/AO, AR/A shall meet the standards of Section 5.0 using the higher of either the applicable AR Zone elevation (as determined from subsections 10.11.230(1) or (2) above) or the base flood elevation (or flood depth) for the underlying A1-30, AE, AH, AO, or A Zone.

b. All substantial improvements to existing construction within Zones AR/A1-30, AR/AE, AR/AH, AR/AO, or AR/A shall meet the standard of Section 10.11.170 using the base flood elevation (or flood depth) for the underlying A1-30, AE, AH, AO, or A Zone.

(Ord. No. 01-06, § 1(3.20.230), 6-21-2001)

The variance criteria set forth in this section of the chapter 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 granted for a parcel of property with physical characteristics so unusual that complying with the requirements of this chapter 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.

It is the duty of the City to help protect its citizens from flooding. This need is so compelling and the implications of the cost of insuring a structure built below flood level are so serious that variances from the flood elevation or from other requirements in the flood ordinance are quite rare. The long-term goal of preventing and reducing flood loss and damage can only be met if variances are strictly limited. Therefore, the variance guidelines provided in this chapter are more detailed and contain multiple provisions that must be met before a variance can be properly granted. The criteria are designed to screen out those situations in which alternatives other than a variance are more appropriate.

(Ord. No. 01-06, § 1(3.20.240), 6-21-2001)

(a) In passing upon requests for variances, the City shall consider all technical evaluations, all relevant factors, standards specified in other sections of this chapter, and the:

(1) Danger that materials may be swept onto other lands to the injury of others;

(2) Danger of life and property due to flooding or erosion damage;

(3) 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) Importance of the services provided by the proposed facility to the community;

(5) Necessity to the facility of a waterfront location, where applicable;

(6) Availability of alternative locations for the proposed use, which are not subject to flooding or erosion damage;

(7) Compatibility of the proposed use with existing and anticipated development;

(8) Relationship of the proposed use to the comprehensive plan and floodplain management program for that area;

(9) Safety of access to the property in time of flood for ordinary and emergency vehicles;

(10) Expected heights, velocity, duration, rate of rise, and sediment transport of the flood waters expected at the site; and

(11) 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.

(b) Any applicant to whom a variance is granted shall be given written notice over the signature of a community official that:

(1) The issuance of a variance to construct a structure below the base flood level will result in increased premium rates for flood insurance up to amounts as high as $25.00 for $100.00 of insurance coverage; and

(2) Such construction below the base flood level increases risks to life and property. It is recommended that a copy of the notice shall he recorded by the Floodplain Administrator in the Office of the Orange County Recorder and shall be recorded in a manner so that it appears in the chain of title of the affected parcel of land.

(c) 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. No. 01-06, § 1(3.20.250), 6-21-2001)

(a) Generally, variances may be issued for new construction, and other proposed new development to be erected on a lot of one-half acre or less in size contiguous to and surrounded by lots with existing structures constructed below the base flood level, providing that the procedures of Sections 10.11.140 et seq. and 10.11.170 et seq., of this chapter have been fully considered. As the lot size increases beyond one half acre, the technical justification required for issuing the variance increases.

(b) 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 the City 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 City believes will both provide relief and preserve the integrity of the local ordinance.

(c) Variances shall only be issued upon a:

(1) Showing of good and sufficient cause;

(2) Determination that failure to grant the variance would result in exceptional "hardship" to the applicant; and

(3) Determination that the granting of a variance will not result in increased flood heights, additional threats to public safety, or extraordinary public expense, create a nuisance (as defined in Section 10.11.050 of this chapter), cause fraud or victimization (as defined in Section 10.11.050) of the public, or conflict with existing local laws or ordinances.

(d) Variances may be issued for new construction, substantial improvement, and other proposed new development necessary for the conduct of a functionally dependent use provided that the provisions of subsections 3.20.260(a) through 3.20.260(e) are satisfied and that the structure or other development is protected by methods that minimize flood damages during the base flood and does not result in additional threats to public safety and does not create a public nuisance.

(e) Upon consideration of the factors of subsection 10.11.250(a) and the purposes of this chapter, the City may attach such conditions to the granting of variances as it deems necessary to further the purposes of this chapter.

(Ord. No. 01-06, § 1(3.20.260), 6-21-2001)