Chapter 17.34 — FLOODPLAIN MANAGEMENT

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. The City Council of the City of Jackson does adopt the following floodplain management regulations.

• 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.

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 areas of special flood hazard assume responsibility for their actions.

In order to accomplish the above 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 hazards, or which result in damage increases in erosion or flood heights or velocities;

• B. Require that uses vulnerable to floods, including facilities which serve the 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 flood waters;

• D. Control, file, grade, dredge and other development which may increase flood damage; and

• E. Prevent or regulate the construction of flood barriers which will unnaturally divert flood waters or which may increase flood hazards in other areas.

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 principle 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 fine sediments that have been eroded from mountain slopes, transported by flood flows, and then deposited on the valley floors. These deposits are 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 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-related erosion hazard" is the land within a community which is most likely to be subject to severe flood-related erosion losses. The area may be designated as Zone E on the Flood Insurance Rate Map (FIRM).

"Area of special flood hazard" See "Special flood hazard area."

"Area of special mudslide (i.e., mudflow) hazard" is the area subject to severe mudslides (i.e., mudflows). The area is designated a Zone M on the Flood Insurance Rate Map (FIRM).

"Base flood" means a flood which has a one percent chance 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.

"Base Flood Elevation (BFE)" is the water surface elevation of the floodplain generated by the base flood at the area of interest as presented in the current Flood Insurance Study and the Flood Insurance Rate Map (FIRM) published by FEMA for the City of Jackson.

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

"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 material which is not part of the structural support of the building. These walls 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 flood waters. A breakaway wall shall have a safe design loading resistance of not less than 10 and no more than 20 pounds per square foot. Use of breakaway walls must be certified by a registered engineer or architect and shall meet the following conditions:

1. Breakaway wall collapse shall result from a water load less than that which would occur during the base flood; and

2. 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.

"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, 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 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).

"Fill" means material from any source placed, or proposed to be placed, within FEMA designated floodplain boundaries. Material that has been placed before the date of the first National Flood Insurance Program (NFIP) map (February 1990, National Flood Insurance Program map) showing the area in a Special Flood Hazard Area (SFHA) is considered natural grade by FEMA.

"Flood," "flooding," "flood water" 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., mudflow)—see "Mudslides"; and

2. The condition resulting from flood-related erosion; see "Flood-related erosion."

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

"Floodplain" or "flood-prone 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" means this Chapter and other zoning ordinance, subdivision regulations, building codes, health regulations, special purpose ordinance (such as grading and erosion control) and other application of entitlements 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 structures which reduce or eliminate flood damage to real estate or improved real property, water and sanitary facilities, structures, and their contents.

"Flood-related erosion" means the collapse or subsidence of land along the shore of any body of water as a result of undermining caused by water exceeding anticipated cyclical levels. This occasion of unusually high water level in a natural body of water can be the result of a severe storm, or by an unanticipated force of nature, such as a flash flood accompanied by a severe storm, an unanticipated force of nature, such as a flash flood or a similarly unusual and unforeseeable event which results in flooding.

"Flood-related erosion area" or "flood-related erosion prone area" means a land area adjoining the shore of a lake or other body of water, which due to the composition of the shoreline or bank and high water levels or wind-driven currents, is likely to suffer flood-related erosion damage.

"Flood-related erosion area management" means the operation of an overall program of corrective and preventive measures for reducing flood-related erosion damage, including but not limited to emergency preparedness plans, flood-related erosion control works, and floodplain management regulations.

"Floodway" means that area inside the floodplain, centered more or less about the watercourse thread, the width of which is presented in the current Flood Insurance Study (FIS) and the limits of which are shown on the current Flood Insurance Rate Map (FIRM). Within this area encroachment is permitted unless it can be proven by accepted engineering methods that the encroachment will not increase the water surface elevation of the floodway.

"Floodway encroachment lines" means the lines marking the limits of floodways on Federal, State and local floodplain maps.

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

"Fraud and victimization" as related to Sections 17.34.260 through 17.34.080 of this Chapter, means that the variance granted must not cause fraud on or victimization of the public. In examining this requirement, the Jackson City Council 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.

"Functionally dependent use" means a use which cannot perform its intended purpose unless it is located or carried out in close proximity to water.

"Governing body" means the local government 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 Sections 17.34.260 through 17.34.280 of this Chapter, means the exceptional hardship that would result from a failure to grant the requested variance. The City Council requires that the variance be exceptional, unusual, and specific 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, requires the property owner to build elsewhere, to use the parcel differently than originally intended.

hetic 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, requires the property owner to build elsewhere, to use the parcel differently 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 States with historic preservation programs which have been approved by the Secretary of the 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 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 Adjacent Grade (LAG)" means that lowest ground elevation that is adjacent to and touching the footings of an existing or proposed structure.

"Lowest floor" means the lowest floor of the lowest enclosed area including basement. An unfinished or flood resistant enclosure, useable solely for parking of vehicles, building access or storage in an area other than a basement area (see "basement"). This floor shall not be the structure's lowest floor, provided that such enclosure is not built so as to render the structure in violation of the applicable non-elevation design requirements of this Chapter. (Note: This definition allows attached garages to be built at grade. Below grade garages are not allowed as they are considered to be basements.)

"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" mean a parcel (or contiguous parcels) of land divided into two or more manufactured home lots for rent or sale.

"Mean sea level" means for the purpose 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.

"Mudslide" (i.e., mudflow) describes a condition where there is a river, flow or inundation of liquid mud down a hillside, usually as a result of a dual condition of loss of brush cover and the subsequent accumulation of water on the ground, preceded by a period of unusually heavy or sustained rain.

"Mudslide (i.e., mudflow) prone area" means an area with land surfaces and slopes of unconsolidated material where the history, geology, and climate indicate a potential for mudflow.

"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, 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.

"One-hundred-year flood" —See "base flood."

"Principal structure" means a structure used for the primary use distinguished from an accessory use.

"Public safety and nuisance" as related to Sections 17.34.260 through 17.34.280 of this Chapter, means the granting of a variance must not result in anything that is injurious to the safety or health of an entire community or neighborhood, or any considerable number of persons, or unlawfully obstructs the free passage or use, in the customary manner, of any navigable lake, 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.

"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 having special flood, mudslide (i.e. mudflow), or floodrelated erosion hazards, and shown on an FHBM or FIRM as Zone A, AO, A1-A30, AE, A99, AH, E, M, V1-V30, VE or V.

"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 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, installation of piles, 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 the following: land preparation, such as clearing, grading, and filling; the installation of streets and/or walkways; excavation for a basement, footings, piers, or foundations or the erection of temporary forms; nor does it include the installation 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 predamaged condition would equal or exceed 50 percent of the market value of the structure.

"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 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 necessary to assure safe living conditions; or

2. Any alteration of a "historic structure," provided 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 ordinance.

"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.

"Zone A" means Special Flood Hazard Area with no base flood elevations.

"Zone A1-A30" means Special Flood Hazard Area with base flood elevations.

"Zone AH" means Special Flood Hazard Area with flood depths of one to three feet (usually areas of ponding); base flood elevations determined.

"Zone AO" means Special Flood Hazard Area with flood depths of one to three feet (usually sheet flow on sloping terrain); average depths determined. For areas of alluvial fan flooding, velocities also determined.

"Zone A99" means Special Flood Hazard Area to be protected from the 100-year flood by a Federal flood protection system under construction; no base flood elevations determined.

"Zone AR" means 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 grater level of flood protection.

"Zone B" means areas between the limits of the 100-year and 500-year flood; or certain areas subject to 100-year flooding with average depths less than one foot or where contributing drainage area is less than one square mile; or areas protected by levees from the 100-year flood.

"Zone C" means areas of minimal flooding.

"Zone D" means areas of undetermined, but possible flood hazards.

"Zone V" means Coastal Special Flood Hazard Areas with velocity hazard (wave action); no base flood elevations determined.

"Zone V1-V30" means Coastal Special Flood Hazard Areas with velocity hazard (wave action) and base flood elevations.

"Zone VE" means Coastal Special Flood Hazard Area with velocity hazard (wave action) and base flood elevations.

"Zone X (shaded)" means areas of 500-year flood; areas of 100-year flood with average depths less than one foot or where contributing drainage area is less than one square mile; or areas protected by levees from the 100-year flood.

"Zone X (unshaded)" means areas determined to be outside the 500-year floodplain.

FEMA Acronyms for Changes and Amendments to the FIRM.

"Conditional Letter of Map Amendment (CLOMA)" a letter from FEMA stating that a proposed structure(s) that is not to be elevated by fill (natural grade) would not be inundated by the base flood if built as proposed.

"Conditional Letter of Map Revision (CLOMR)" a letter from FEMA commenting on whether a proposed project, if built as proposed, would justify a map revision, or proposed hydrology changes.

"Conditional Letter of Map Revision due to Fill (CLOMR-F)" a letter from FEMA stating that a parcel of land or proposed structure(s) that will be elevated by fill would not be inundated by the base flood if fill is placed on the parcel as proposed or the structure(s) is built as proposed.

"Letter of Map Amendment (LOMA)" a letter from FEMA stating that an existing structure(s) or parcel of land that has not been elevated by fill (natural grade) would not be inundated by the base flood.

"Letter of Map Change (LOMC)" a letter from FEMA to revise or amend the flood hazard information shown on the FIRM or DFIRM without requiring the FIRM or DFIRM to be physically revised and republished.

"Letter of Map Revision (LOMR)" a letter from FEMA officially revising the current NFIP map to show the changes to the floodplain, regulatory floodway, or flood elevations.

"Letter of Map Revision due to Fill (LOMR-F)" a letter from FEMA stating that an existing structure(s) or parcel of land that has been elevated by fill would not be inundated by the base flood.

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

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 09/28/90 and accompanying Flood Insurance Rate Maps (FIRMs), dated 09/28/90, 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 Council by the floodplain administrator. The study, FIRMs and FNFMs are on file at the Jackson City Office, City Hall, 33 Broadway, Jackson, California.

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. 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 Council from taking such lawful action as is necessary to prevent or remedy any violation.

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.

In the interpretation and application of this Chapter, all provisions shall be:

• A. Considered as minimum requirements;

• B. Liberally construed in favor of the governing body; and

• C. Deemed neither to limit nor repeal any other powers granted under State statutes.

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 may be increased by man-made or natural causes. This Chapter does not imply that land outside the areas of special flood hazards, or uses permitted within these areas will be free from flooding or flood damages. This Chapter shall not create liability on the part of the City Council, any officer or employee thereof, the State of California, or the Federal Insurance Administration, Federal Emergency Management Agency, for flood damages that result from reliance on this Chapter or any administrative decision lawfully made hereunder.

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 chapter as a whole, or any portion thereof other than the section so declared to be unconstitutional or invalid.

A development permit shall be obtained before any construction or other development begins within any area of special flood hazard established in Section 17.34.070 (Basis for Establishing the Areas of Special Flood Hazard). 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:

• A. Proposed elevation in relation to mean sea level, of the lowest floor (including basement) of all structures in Zone AO, elevation of highest adjacent grade and proposed elevation of lowest floor of all structures; or

• B. Proposed elevation in relation to mean sea level to which any structure will be floodproofed, if required in Section 17.34.170(C)(3) (Standards of Construction); and

• C. All appropriate certifications listed in Section 17.34.150(D) (Duties and Responsibilities of the Floodplain Administrator) of this Chapter; and

• D. Description of the extent to which any watercourse will be altered or relocated as a result of proposed development.

The City Manager or his/her designee shall be the floodplain administrator and shall have the authority to administer, implement and enforce this Chapter by granting or denying development permits in accord with its provisions.

The duties and responsibilities of the floodplain administrator shall include, but not be limited to, the following.

• A. Permit Review. Review all development permits to determine that:

  1. Permit requirements of this Chapter have been satisfied;

  2. All other required State and Federal permits have been obtained;

  3. The site is reasonably safe from flooding; and

  4. 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.

• B. Review and Use of Any Other Base Flood Data. When base flood elevation data has not been provided in accordance with Section 17.34.070 (Basis for Establishing the Areas of Special Flood Hazard), the floodplain administrator shall obtain, review, and reasonably utilize any base flood elevation and floodway data available from a Federal or State agency, or other source, in order to administer Sections 17.34.170 through 17.34.250 . Any such information shall be submitted to the City Council for adoption.

• C. Notifcation of Other Agencies. In alteration or relocation of a watercourse:

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

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

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

• D. Documentation for Floodplain Development. Obtain and maintain for public inspection and make available as needed the following:

  1. Certification required by Section 17.34.170(C)(1) (floor elevations);

  2. Certification required by Section 17.34.170(C)(2) (elevation or floodproofing of nonresidential structures);

  3. Certification required by Section 17.34.170(C)(3) (wet floodproofing standard);

  4. Certification of elevation required by Section 17.34.190(B) (subdivision standards);

  5. Certification required by Section 17.34.220(A) (floodway encroachments);

  6. Information required by Section 17.34.230(F) (coastal construction standards); and

  7. Reports required by Section 17.34.240(D) (mudflow standards).

• E. 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. The person contesting the location of the boundary shall be given a reasonable opportunity to appeal the interpretation as provided in Sections 17.34.260 through 17.34.280 .

e 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. The person contesting the location of the boundary shall be given a reasonable opportunity to appeal the interpretation as provided in Sections 17.34.260 through 17.34.280 .

• F. Remedial Action. Take action to remedy violations of this Chapter as specified in Section 17.34.080 (Compliance).

The City Council 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.

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

A. Anchoring.

1. All new construction and substantial improvements 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.

2. All manufactured homes shall meet the anchoring standards of Section 17.34.200 (Standards for Manufactured Homes).

• B. Construction Materials and Methods. All new structures and substantial improvement shall be constructed:

  1. With materials and utility equipment resistant to flood damage;

  2. Using methods and practices that minimize flood damage;

  3. 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

  4. Within Zones AH or AO, so that there are adequate drainage paths around structures on slopes to guide flood waters around and away from proposed structures.

• C. Elevation and Floodproofng. (See Section 17.34.050 (Definitions) for "new construction," "substantial damage" and "substantial improvement."

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

     • a. 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 Flood Insurance Rate Map (FIRM), or elevated at least two feet above the highest adjacent grade if no depth number is specified. The State of California recommends that the lowest flood be elevated above the highest adjacent grade if no depth number is specified.

     • b. In an A zone, elevated to or above the base flood elevation, as determined by this community. The State of California recommends the lowest floor be elevated at least one foot above the base flood elevation, as determined by the Building Official.

     • c. In all other zones, elevated to or above the base flood elevation. The State of California recommends the lowest floor be elevated at least one foot 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, or verified by the Building Official to be properly elevated. Such certification or verification shall be provided to the floodplain administrator.

  2. Nonresidential construction shall either be elevated to conform with Section 17.34.170(C) (1) (floor elevations) or together with attendant utility and sanitary facilities:

     • a. Be floodproofed below the elevation recommended under Section 17.34.170(C)(1) (floor elevations) so that the structure will not sustain damage due to the passage of water;

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

• c. 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.

  3. All new construction and substantial improvement 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 must exceed the following minimum criteria:

     • a. Be certified by a registered professional engineer or architect; or

  • b. Be certified to comply with a local floodproofing standard approved by the Federal Insurance Administration, Federal Emergency Management Agency; or

  • c. 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 food above grade. Openings may be equipped with screen, louvers, valves or other coverings or devices provided that they permit the automatic entry and exit of floodwater.

4. Manufactured homes shall also meet the standards in Section 17.34.200 (Floodways).

• A. All new and replacement water supply and sanitary sewage systems shall be designed to minimize or eliminate:

  1. Infiltration of flood waters into the system; and

  2. Discharge from systems into floodwaters.

• B. On-site waste disposal systems in the floodwaters shall be located to avoid impairment to them or contamination from them during flooding.

• A. All preliminary subdivision proposals shall identify the flood hazard area and the level of the base flood.

• B. All subdivision plans will provide the elevation of proposed structure(s) and pad(s). If the site is filled above the base flood elevation, the final first 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.

• 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 (the State of California recommends at least one foot above

the base flood elevation) and be securely anchored to an adequately anchored foundation system to resist flotation, collapse and later 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 Section 17.34.200(A) .

• 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 paragraph 17.20.200(A) will be elevated so that either:

  1. Lowest floor of the manufactured home is at or above the base flood elevation (the State of California recommends at least one foot 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 not less than 36 inches in height above grade and be securely anchored to an adequately anchored foundation system to resist flotation, collapse, and later movement.

• 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;

  2. 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

  3. Meet the permit requirements of Sections 17.34.130 through 17.34.160 of this Chapter and the elevation and anchoring requirements for manufacture homes in Section 17.34.200(A) .

• B. 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 Section 17.34.210(A) .

Locations within areas of special flood hazard established in Section 17.34.070 (Basis for Establishing the Areas of Special Flood Hazard) are 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.

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

• B. If subsection A is satisfied, all new construction, substantial improvement, and other proposed new development shall comply with all other applicable flood hazard reduction provisions of Sections 17.34.170 (Standards of Construction) through 17.34.250 (Flood-related ErosionProne Areas).

• A. The floodplain administrator shall review permits for proposed construction of other development to determine if it is proposed within a mudslide area.

• B. Permits shall be reviewed to determine that the proposed site and improvement will be reasonably safe from mudslide hazards. Factors to be considered in making this determination include, but are not limited to, the:

  1. Type and quality of soils;

  2. Evidence of groundwater or surface water problems;

  3. Depth and quality of any fill;

  4. Overall slope of the site; and

  5. Weight that any proposed development will impose on the slope.

• C. Within areas which may have mudslide hazards, the floodplain administrator shall require that:

  1. A site investigation and further review be made by persons qualified in geology and soils engineering;

  2. The proposed grading, excavation, new construction, and substantial improvement be adequately designed and protected against mudslide damages;

  3. The proposed grading, excavation, new construction, and substantial improvement not aggravate the existing hazard by creating either on-site or off-site disturbances; and

  4. Drainage, planting, watering, and maintenance not endanger slope stability.

• A. The floodplain administrator shall require permits for proposed construction and other development within all flood-related, erosion-prone areas identified by the community.

• B. Permit applications shall be reviewed to determine whether the proposed site alterations and improvements will be reasonably safe from flood-related erosion and will not cause flood-related erosion hazards or otherwise aggravate the existing hazard.

• C. If a proposed improvement is found to be in the path of flood-related erosion or would increase the erosion hazard, such improvement shall be relocated or adequate protective measures shall be taken to avoid aggravating the existing erosion hazard.

• D. Within Zone E on the Flood Insurance Rate Map, a setback is required for all new development from a body of water to create a safety buffer consisting of a natural vegetative or contour strip. This buffer shall be designated according to the flood-related erosion hazard and erosion rate, in relation to the anticipated "useful life" of structures, and depending upon the geologic, hydrologic, topographic, and climatic characteristics of the land. The buffer may be used for suitable open space purposes, such as for agricultural, forestry, outdoor recreation and wildlife habitat areas, and for other activities using temporary and portable structures only.

• A. The variance criteria set forth in this Section 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 ordinance 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.

• B. It is the duty of the City Council 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.

• A. In passing upon requests for variance, the City Council 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 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 for each $100 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 be recorded by the floodplain administrator in the office of the 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 variance issued in its biennial report submitted to the Federal Insurance Administration and Federal Emergency Management Agency.

• A. Generally, variances may be issued for new construction, substantial improvement, 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 17.34.130 through 17.34.250 have been fully considered. As the lot size increases beyond one-half acre, the technical justification required for issuing the variance increases.

• B. Variances may be issued for the repair or rehabilitation of "historic structures" (as defined in Section 17.34.050 Definitions) upon a determination that the proposed repair or rehabilitation will not preclude the structure's continued designation as an historic structure and the variance is the minimum necessary to preserve the historic character and design of the structure.

• C. Variance shall not be issued within any mapped regulatory floodway if any increase in flood levels during the base flood discharge would result.

• D. 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 ordinance. For example, in the case of variances to an elevation requirement, this means the governing body 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 governing body believes will both provide relief and preserve the integrity of the local ordinance.

• E. 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" (as defined in Section 17.34.050 Definitions) 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 17.34.050 Definitions—see "public safety or nuisance"), cause fraud or victimization (as defined in Section 17.34.050 Definitions) of the public, or conflict with existing local laws or ordinances.

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

• G. Upon consideration of the factors of Section 17.34.270(C) and the purposes of this Chapter, the City Council may attach such conditions to the granting of variances as it deems necessary to further the purposes of this Chapter.

Chapter 17.36. HILLSIDE DEVELOPMENT STANDARDS

§ 17.36.010. Purpose of Chapter.

This Chapter establishes regulations for development within hillside areas in order to:

• A. Preserve and protect the views to and from hillside areas in order to maintain the identity, image and environmental quality of the City of Jackson;

• B. Ensure that development in the hillside areas is concentrated on the most level portions of the site, is in locations with the least environmental impact, and is designed to fit the existing landforms;

• C. Preserve significant features of the natural topography, including swales, canyons, knolls, ridgelines, and rock outcrops;

• D. Correlate intensity of development with the steepness of terrain in order to minimize the impact of grading, unnecessary removal of vegetation, land instability, and fire hazards; and

• E. Provide alternative approaches to conventional flat land development practices by achieving land use patterns and intensities that are consistent with the natural characteristics of hillside areas including slopes, land form, vegetation and scenic quality.

• A. Hillside area. The standards of this Chapter apply to all existing and proposed lots, uses, subdivisions, and structures proposed on development sites with an average slope of 10 percent or greater or on development sites with any slopes of 20 percent or greater; except that single-family dwellings, secondary residential units, duplexes, and residential accessory structures shall be exempt from the provisions of this Chapter.

• B. Basis for slope determinations. For the purpose of this Chapter, slope shall be computed on the natural slope of the land before grading is commenced, as determined from a topographic map having a scale of not less than one inch equals 100 feet and a contour interval of not more than five feet. See Chapter 17.220 (Definitions, Glossary) for definitions on simple slope and complex slope and how to measure slope.

• C. Use Permit required. Hillside developments (other than subdivisions) with any improvements, including roads, streets, and driveways, proposed on slopes of 20 percent or greater shall be subject to the approval of a Use Permit in compliance with Chapter 17.76 (Use Permits and Minor Use Permits). A soil and geotechnical study that identifies special constraints and mitigation measures to minimize grading, unstable soils, and erosion shall accompany the use permit application. The geotechnical study shall also analyze the landslide hazards of the site and their potential effect.

Land use permit and subdivision applications for projects proposed within hillside areas shall include all information and materials required by Section 17.70.040 (Application Preparation and Filing), and all additional information required by the City Planner on the basis of site topography.

• A. Minimum lot area. The minimum lot area for new subdivisions in hillside areas shall be determined by the applicable zoning district, except where housing units are clustered and the project is approved as a Planned Development in compliance with Chapter 17.78 (Planned Developments).

• B. Clustered development required. Proposed hillside development shall be clustered in compliance with Chapter 17.46 (Open Space/Cluster Requirements).

• C. Preservation of steep slopes. Slopes of 30 percent or greater shall be permanently preserved as open space. Permanent open space areas may be used in compliance with Section 17.46.060 (Open Space Standards). Grading, structures, and/or streets on slopes exceeding 20% shall be avoided if there is sufficient area on the site with slopes less than 20% to accommodate development and streets. The Planning Commission may authorize grading and structures on slopes exceeding 30% only if the Commission finds there is not sufficient area on the parcel with slopes less than 30% to accommodate a reasonable development, and measures have been incorporated into the development to minimize disturbance of the terrain (e.g. use of stem walls, split foundations).

• D. Setbacks between structures and slopes. Proposed structures shall be set back from slopes as follows, based on the difference in the vertical elevation between adjoining parcels. The difference in vertical elevation shall be measured as shown in Figure 3-9. (See Figure 3-9, Slope Setbacks)

==> picture [442 x 305] intentionally omitted <==

Figure 3-9 Slope Setbacks

1. On adjacent parcels having a difference in vertical elevation of three feet or more, the required side yard shall be measured from the toe or top of slope to a structure, whichever is nearer.

2. On adjacent parcels having a difference in vertical elevation of six feet or more, the minimum distance between the toe or top of the slope, whichever is nearer, and a main structure shall be 15 feet. Greater setbacks may be required when elevation changes greater than six feet are proposed.

• E. Height limits. The height of structures in a hillside area shall not exceed the maximum established by the applicable zoning district. Measurement of structure height shall be as provided in Section 17.30.090 (Height Measurement and Height Limit Exceptions). Lesser heights may be required where the structure may impair prominent views to or from hillside

areas or ridgelines or where a proposed structure's height intrudes on the flow of adjacent houses and roof lines.

• F. Grading and drainage.

  1. Grading shall be designed to:

     • a. Conserve natural topographic features and appearances by minimizing the amount of cut and fill and by means of landform grading to blend graded slopes and benches with the natural topography; and

     • b. Retain major natural topographic features (i.e., canyons, knolls, ridgelines, and landmarks).

2. Grading plans shall identify slopes that are to be landform graded. "Landform grading" means a contour grading method that creates artificial slopes with curves and varying slope ratios in the horizontal plane designed to simulate the appearance of the surrounding natural terrain. (See Figure 3-10, Landform Grading)

Figure 3-10 Landform Grading

==> picture [421 x 583] intentionally omitted <==

3. Lot pad grading for subdivisions shall be limited to the structure footprint, vehicle parking space and a yard area as shown on the approved grading plan. Lot pad grading shall be reviewed and approved as part of the subdivision process. Pads shall not exceed 5,000 square feet in total area. Smaller pad areas may be required to preserve natural vegetation, landforms, rock outcroppings, etc.

4. Cut and fill slopes shall be designed and constructed to not exceed a vertical height of 10 feet, unless the review authority approves slopes of greater height with benching, terracing, and/or the use of retaining walls.

5. All graded areas shall be protected from wind and water erosion. Interim erosion control plans shall be required, certified by the project engineer, and reviewed and approved by the City Engineer. Permanent erosion control measures in accordance with standard Best Management Practices shall be required.

6. Slopes created by grading shall not exceed a ratio of 2:1 (horizontal: vertical), except where the City Engineer determines that a greater slope is appropriate, based on a soils report and stabilization study.

The following design criteria shall be implemented in the design and construction of projects on hillsides whenever applicable:

• A. Preservation of topography. The natural contour of the site is an important characteristic of the site, and new buildings should try to minimize alterations to the perceived slope of the area. Site grading should be sensitive to existing landforms and topography so that the natural setting may be preserved to the greatest extent possible. Every effort should be made to minimize the limits of construction on the site, and all stockpiling of materials and equipment and equipment storage should occur within those limits. Abrupt grade changes on property lines should not be permitted. Grade changes within tree driplines should be avoided.

• B. Terrain alteration. The project shall be designed to fit the terrain rather than altering the terrain to fit the project. Development patterns which form visually protruding horizontal bands or steeply cut slopes for roads or lots shall be avoided.

• C. Street layout. Streets shall follow the natural contours of the terrain in order to minimize the need for grading. Cul-de-sacs and loop roads are encouraged where necessary to fit the natural topography subject to the approval of the City Engineer and the Fire Chief.

• D. Site and structure design. Site design shall utilize varying structure and setbacks, heights, splitlevel foundations, and retaining walls to terrace structures with the direction of the slope.

• E. Lot line locations. Lot lines shall be placed at the top of slope areas to help ensure that the slope will not be neglected by the up-hill owner. (See Figure 3-11, Lot Line Location)

==> picture [442 x 299] intentionally omitted <==

Figure 3-11 Lot Line Location

• F. Design and location of structures. Structures proposed on slopes shall be designed and located as follows.

  1. The form, mass, and profile of individual buildings and architectural features shall be designed to blend with the natural terrain and preserve the character and profile of the natural slope. Some techniques which may be considered include:

     • a. Split pads, stepped footings and grade separations to permit structure to step up the natural slope.

     • b. Detaching parts of a dwelling (e.g., a garage).

  2. Excessive cantilevers should be avoided on downhill building elevations.

  3. Structures should be placed partly underground or utilize below grade rooms to reduce effective bulk and to provide energy efficient and environmentally desirable spaces. However, the visible area of the building shall be minimized through a combined use of regrading and landscaping techniques.

  4. Roofs on lower levels should be used as the deck open space of upper levels.

  5. Architectural treatment shall be provided to all visible sides of the structure.

  6. Exterior structural supports and undersides of floors and decks not enclosed by walls shall be allowed only if fire safety and aesthetic considerations have been adequately addressed.

7. To the extent possible, the width of a building measured in the direction of the slope, shall be minimized in order to limit the amount of cutting and filling and to better "fit" the house to the natural terrain.

   8. Structures shall be placed to minimize disturbance of natural vegetation on all lots but particularly on lots with slopes of 10 percent or greater.

• G. Retaining walls. Large retaining walls in a uniform plane shall be avoided. Retaining walls over five feet in height shall be divided into elements and terraces with landscaping to screen them from view. Generally, no retaining wall should be higher than 10 feet. Where feasible, retaining walls should be constructed of the same materials as the primary buildings on the site. (See Figure 3-12, Retaining Wall Design)

Figure 3-12 Retaining Wall Design

==> picture [442 x 259] intentionally omitted <==

• H. Open space preservation. Open space may be preserved by reducing the width of street improvements, reducing sidewalk widths, using common driveways and clustering units subject to the approval of the City Engineer and Fire Chief.

• I. Slope restoration. Transitional slopes shall be replanted with self-sufficient trees, shrubs and ground cover that are compatible with existing surrounding vegetation in order to enhance the blending of manufactured and natural slopes. Cuts and fills shall have good surface drainage and shall be revegetated and terraced or controlled by retaining walls to protect against erosion and sedimentation. (See Figure 3-13, Slope Restoration)

Figure 3-13 Slope Restoration

==> picture [442 x 260] intentionally omitted <==

• J. Road alignment. The alignment of roads and driveways should follow the contours of the site. By meandering roads and driveways to follow landforms, it is possible to minimize cuts and fills, preserve natural drainage patterns, and produce roads that are easily negotiated. Roads should not be constructed perpendicular to contours.

• K. Reduced street widths. On-street parking lanes may be omitted from streets when the result is a substantial decrease in cutting and/or filling. Off-street parking areas shall be provided to yield a ratio of one additional space per dwelling unit.

• L. Preservation of ridgelines. Ridgelines shall be preserved. Structures located adjacent to prominent ridgelines should complement, rather than provide a stark contrast with, the natural landform(s). Structures shall not be closer to a prominent ridgeline than 100 feet measured horizontally on a topographic map. In no case, shall the roofline or any other portion of a structure extend above the line of sight between a ridgeline and any public right-of-way, whether the ridgeline is above or below the right-of-way. (See Figure 3-14, Development Preserves Ridgeline)

==> picture [442 x 246] intentionally omitted <==

Figure 3-14 Development Preserves Ridgeline

The Commission shall evaluate a Use Permit application for hillside development based on the following objectives, and the findings required for Use Permits by Chapter 17.76 (Use Permits and Minor Use Permits):

• A. The preservation of natural topographic features and appearances by means of landform grading so as to blend constructed slopes into the natural topography;

• B. The preservation of natural topographic features and appearances through restrictions on successive padding and terracing of building sites;

• C. The retention of major natural topographic features - drainage courses, steep slopes, watershed areas, vernal pools, view corridors, and scenic vistas;

• D. The preservation and enhancement of landmark features - ridgelines, rock outcroppings, heritage sized trees and woodlands, mining ruins, other points of historical interest, and other areas of special natural beauty;

• E. The use of varying setbacks, building heights, foundation designs and compatible building forms, materials, and colors which serve to blend buildings into the terrain;

• F. The use of clustered sites and buildings on more gently sloping terrain so as to reduce grading alterations on steeper slopes;

• G. The use of building designs, locations, and arrangements which do not intrude with the skyline effect and which afford view privacy and protection;

• H. The preservation and introduction of plant materials to protect slopes from soil erosion and slippage and minimize the visual effects of grading and construction of hillside areas; and

• I. The use of street designs and improvements which serve to minimize grading alterations and harmonize with the natural contours and character of the hillsides.