Earlier editions: 2026-09
Chapter 29 — FLOODPLAIN MANAGEMENT.
Alturas Municipal Code Art. I Statutory Authorization, Findings of Fact, Purpose and Methods
Alturas Municipal Code · 2026-10 edition · updated 2026-10-04 · Alturas
Cite as: Alturas Municipal Code Article I · Text as of 2026-10-04
Sec. 29-1. - 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. Therefore, the city council of the city does adopt the following floodplain management regulations.
(Ord. No. 477, § 2, 12-9-2008)
Sec. 29-2. - Findings of fact.¶
(a) The flood hazard areas of the city 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 uses that are inadequately elevated, floodproofed, or protected from flood damage. The cumulative effect of obstructions in areas of special flood hazards which increase flood heights and velocities also contribute to the flood loss.
(Ord. No. 477, § 2, 12-9-2008)
Sec. 29-3. - 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 to:
(a) Protect human life and health;
(b) Minimize expenditure of public money for costly flood control projects;
(c) Minimize the need for rescue and relief efforts associated with flooding and generally undertaken at the expense of the general public;
(d) Minimize prolonged business interruptions;
(e) 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;
(f) 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;
(g) Ensure that potential buyers are notified that property is in an area of special flood hazard; and
(h) Ensure that those who occupy the areas of special flood hazard assume responsibility for their actions.
(Ord. No. 477, § 2, 12-9-2008)
Sec. 29-4. - Methods of reducing flood losses.¶
In order to accomplish it purpose, this chapter includes methods and provisions to:
(a) Restrict or prohibit uses which are dangerous to health, safety, and property due to water or erosion flood heights or velocities;
(b) Require that uses vulnerable to floods, including facilities which serve such uses, be protected against flood damage at the time of initial construction;
(c) Control the alteration of natural floodplains, stream channels, and natural protective barriers, which help accommodate or channel floodwaters;
(d) Control filling, grading, dredging, and other development which may increase flood damage; and
(e) Prevent or regulate the construction of flood barriers which will unnaturally divert floodwaters or which may increase flood hazards in other areas.
(Ord. No. 477, § 2, 12-9-2008)
Sec. 29-5. - Definitions.¶
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.
"Appeal" means a request for a review of the floodplain administrator's interpretation of any provision of this chapter.
"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 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 flooding 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 change of being equaled or exceeded in any given year (also called the "one-hundred-year flood"). Base flood is the term used throughout this chapter.
"Basement" means any area of the building having its floor sub-grade, i.e., below ground level, on all sides.
"Building." See "Structure."
"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 alter 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 loss 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, flooding or floodwater" means 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 or surface waters from any source.
"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.
"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 an examination, evaluation and determination of flood hazards and, if appropriate, corresponding water surface elevations, or an examination, evaluation and determination of mudslide (i.e., mudflow) and/or flood related erosion hazards."
"Floodplain or flood-prone area" means any land area susceptible to being inundated by water from any source. See "Flooding".
"Floodplain administrator" means 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" means 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 flood-prone 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 nonresidential 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 encroachment lines" means the lines marking the limits of floodways on federal, state and local floodplain maps.
"Floodway fringe" is that area of the floodplain on either side of the "regulatory floodway" where encroachment may be permitted.
"Fraud and victimization" as related to article V, variance procedure, of this chapter, means that the variance granted must not cause fraud on or victimization of the public. In examining this requirement, the planning commission will consider the fact that every newly constructed building adds to government responsibilities and remains a part of the community for fifty to one hundred 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.
"Functionally dependent use" means a use, which cannot perform its intended purpose unless it 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, and does not include long-term storage or related manufacturing facilities.
"Governing body" is the local governing unit, i.e., county or municipality, 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 article V, variance procedure, of this chapter means the exceptional hardship that would result from a failure to grant the requested variance. The planning commission 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 at 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.
"Historic structure" means any structure that is:
(1) Listed individually in the National Register of Historic Places (a listing maintained by the Department of Interior) or preliminarily determined by the Secretary of the Interior as meeting the requirements for individual listing on the National Register;
(2) 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;
(3) Individually listed on a state inventory of historic places in communities with historic preservation programs which have been approved by the Secretary of Interior; or
(4) 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 with approved programs.
"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" definition).
(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 29-16(c)(3);
b. The anchoring standards in subsection 29-16(a);
c. The construction materials and methods standards in subsection 29-16 (b);
d. The standards for utilities in section 29-17.
(2) For residential structures, all sub-grade enclosed areas are prohibited as they are considered to be basements. 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.
"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 water course 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.
"One hundred year flood." See "Base flood."
"Public safety and nuisance" as related to article V, variance procedure, of this chapter 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 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) Designed 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 this chapter 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.
"Sheet flow area." See "Area of shallow flooding."
"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 an FHBM or FIRM as Zone A, AO, A1-A30, AE, A99, or AH.
"Start of construction" includes substantial improvement and other proposed new development and means the date the building permit was issued, provided the actual start of construction, repair, reconstruction, rehabilitation, addition, placement, or other improvement was within one hundred eighty 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 manufactured home on a foundation. Permanent construction does not include land preparation, such as clearing, grading, and filling; nor does it include the installation of streets and/or walkways; nor does it include excavation for a basement, footings, piers, or foundations or the erection of temporary forms; nor does it include the installation on the property of accessory buildings, such as garages or sheds not occupied as dwelling units or not part of the main structure. For a substantial improvement, the actual start of construction means the first alteration of any wall, ceiling, floor, or other 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 fifty 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, which is subject to the issuance of a building permit, the cost of which equals or exceeds fifty percent of the market value of the structure before the "start of construction" of the improvement. This term includes structures which have incurred "substantial damage", regardless of the actual repair work performed. The term does not, however, include either:
(1) Any project for improvement of a structure to correct existing violations or state or 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; or
(2) Any alteration of a "historic structure", provided that the alteration will not preclude the structure's continued designation as a "historic structure."
"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. The planning commission is charged with the duty to hear and decide variances. The city council shall hear and decide appeals from the planning commission when it is believed the commission has erred in any order, requirement, decision or determination.
"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 floods of 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. 477, § 2, 12-9-2008; Ord. No. 502, § 1, 11-18-2014)
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