A.
The
special flood hazard areas of the City of Napa 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. Uses that are inadequately
elevated, flood proofed, or protected from flood damage contribute
to flood losses. The cumulative effect of obstructions in the special
flood hazard area which increase flood heights and velocities also
contribute to the flood loss.
B.
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 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;
8.
Ensure
that those who occupy the areas of special flood hazard assume responsibility
for their actions;
9.
Implement
the regulations of the National Flood Insurance Program and Related
Regulations (as outlined in Part 44 of the Code of Federal Regulations)
and administered by the Federal Emergency Management Agency (FEMA);
and
10.
Implement the policies of the health and safety element of the General
Plan regarding flood hazards with the Napa River and its tributaries.
C.
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 hazards, or result in damaging increases in 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 flood waters or which may increase flood hazards in other areas.
D.
The
degree of flood protection required by these regulations is considered
reasonable for regulatory purposes and is based on scientific and
engineering considerations. Larger floods will occur on rare occasions.
Flood heights may be increased by manmade or natural causes. These
regulations do not imply that land outside the areas of special flood
hazard, or uses permitted within such areas will be free from flooding
or flood damages. These regulations shall not create liability on
the part of the city, any officer or employee thereof, or the Federal
Insurance Administration, for any flood damages that result from reliance
on these regulations, or any administrative decision lawfully made
there under.
(O2003-12)
A.
It
is the intent that this chapter shall apply to all special flood hazard
areas within the jurisdiction of the City of Napa. These special flood
hazard areas are identified by the Federal Insurance Administration
(FIA) of the Federal Emergency Management Agency (FEMA) in the Flood
Insurance Study (FIS) dated September 26, 2008 and accompanying Flood
Insurance Rate Maps (FIRMs) and Flood Boundary and Floodway Maps (FBFMs)
dated September 26, 2008, as revised under the FEMA Letter of Map
Revision submittal dated April, 2008, and as set forth in the revised
2008 LOMR Mapping Documents. All subsequent amendments and/or revisions
thereto are hereby adopted and incorporated by reference into 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 FIS, FIRMs
and FBFMs are on file at the Department of Public Works, 1600 First
Street, Napa, California. The provisions of this chapter shall apply
to those lots shown on the zoning map (along with the zoning district
with which they are combined) with an "FP" suffix.
B.
No
development project may hereinafter be undertaken without full compliance
with the terms of this chapter and any term, condition, mitigation
measure or project description incorporated into any permit or other
entitlement granted. Violation of any permit term, condition mitigation
measure, project description or applicant misrepresentation shall
be unlawful, prohibited and a violation of this title.
C.
This
chapter is not intended to repeal, abrogate, or impair any existing
easements, covenants, or deed restrictions.
D.
Where
this chapter and another law, regulation or ordinance conflict or
overlap, whichever imposes the more stringent restrictions shall prevail.
(O2003-12; O2009 7; O2009 8)
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 the chapter its most reasonable application.
The specific definitions below are intended for use only in conjunction
with the regulations contained herein.
See "Special flood hazard area."
means a flood that has a one percent chance of being equaled
or exceeded in any given year (also known as the "100-year flood").
means any area of the building having its floor subgrade
(below ground level) on all sides.
means any structure intended for any use or occupancy with
substantial walls and roof. "Building" includes "manufactured home."
means any man-made change to improved or unimproved real
estate, including, but not limited to, buildings or other structures,
mining, dredging, filling, grading, paving, excavation or drilling
operations. It includes the construction or placement of new buildings
and structures or substantial improvement of existing buildings and
structures but does not normally include maintenance, painting and
minor repairs. Development also includes a change of use which requires
a use permit under this title, approval of a tentative subdivision
map or parcel map and establishment of a manufactured home or mobile
home park. Development also includes the storage of equipment and
materials where such storage may increase the base flood elevation
result in water damage to the stored equipment or materials or result
in the equipment or material becoming water borne debris.
means any project undertaken for the purpose of development.
means the advance or infringement of uses, plant growth,
fill, excavation, buildings, permanent structures or development into
a floodplain that may impede or alter the flow capacity of a floodplain.
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) was completed before March 1988.
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 installation of utilities, the construction
of streets, and either final site grading or the pouring of concrete
pads).
means a general and temporary condition of partial or complete
inundation of normally dry land areas from the overflow of inland
or tidal waters or the unusual and rapid accumulation of runoff of
surface waters from any source.
means the official map on which the Federal Emergency Management
Agency (FEMA) or Federal Insurance Administration (FIA) has delineated
both the special flood hazard area and the floodway.
means the official map on which FEMA or FIA has delineated
both the special flood hazard area and the risk premium zones applicable
to the community.
means the official report provided by the FIA that includes
flood profiles, the FIRM, the FBFM, and the water surface elevation
of the base flood.
means any land area susceptible to being inundated by water
from any source. See "Flood, flooding or flood water."
is the Director of Public Works.
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.
means this chapter and other zoning chapters, subdivision
regulations, building codes, health regulations, special purpose chapters
(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.
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. (Applicable to "Floodplain
management regulations" only.)
means the channel of a river or other water course 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."
is that area of the floodplain on either side of the "regulatory
floodway" where encroachment may maybe permitted.
means a use which cannot perform its intended purpose unless
it is located or carried out in close proximity to water. The term
includes only docking facilities, port facilities that are necessary
for the loading and unloading of cargo or passengers, and ship building
and ship repair facilities, and does not include long-term storage
or related manufacturing facilities.
as related to Section 17.38.100 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 peculiar to the property involved. Mere economic or financial hardship alone is not exceptional. Inconvenience, physical problems, aesthetic considerations, 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 they are more expensive, or require the property owner to build elsewhere or put the parcel to a different use than originally intended.
means the highest natural elevation of the ground surface
prior to construction next to the proposed walls of a structure.
means any structure that is:
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;
Certified or preliminarily determined by the Secretary of 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;
Individually listed on the state of California inventory of
historic places; or
Individually listed as a City of Napa landmark on the local
inventory of historic places.
means a man-made 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.
means a flood protection system that 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.
means the lowest floor of the lowest enclosed area including
basement (see "Basement" definition).
An unfinished or flood resistant enclosure below the lowest
floor that is useable solely for parking of vehicles, building access
or storage in an area other than a basement areas, is not considered
a building's lowest floor provided it conforms to applicable non-elevation
design requirements including but not limited to:
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.
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."
means a parcel (or contiguous parcels) of land divided into
two or more manufactured home lots for rent or sale.
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.
for floodplain management purposes, means structures for
which the "start of construction" commenced on or after March 1988
and includes any subsequent improvements to such structures.
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) was completed on or after March 1988.
includes, but is not limited to, any dam, wall, wharf, embankment,
levee, dike, pile, abutment, protection, excavation, channelization,
bridge, conduit, culvert, building, wire, fence, rock, gravel, refuse,
fill, structure, vegetation or other material in, along, across or
projecting into any watercourse which may alter, impede, retard or
change the direction and/or velocity of the flow of water, or due
to its location, its propensity to snare or collect debris carried
by the flow of water, or its likelihood of being carried downstream.
See "Base flood."
means a vehicle which is:
Built on a single chassis;
400 square feet or less when measured at the largest horizontal
projection;
Designed to be self-propelled or permanently towable by a light-duty
truck (rated two tons or less); and
Designed primarily not for use as a permanent dwelling but as
temporary living quarters for recreational, camping, travel or seasonal
use.
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.
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.
means all Flood Insurance Rate Maps and associated Flood
Insurance Studies as contained in the City of Napa's Federal Emergency
Management Agency Letter of Map Revision submittal dated April 2008,
and as mapped in FEMA document numbers 06055C0504E, 06055C0505E, 06055C0508E,
06055C0509E, 06055C0510E, 06055C0512E, 06055C0515E, 06055C0516E, 06055C0517E,
06055C0518E, 06055C0519E, 06055C0610E, 06055C0650E, Index number 06055CIND0A,
and Flood Insurance Study number 0655CV000A.
means relating to, formed by, or resembling a river (including
tributaries), stream, brook, etc.
See "Area of shallow flooding."
means an area having special flood, mud slide (i.e., mud
flow), or flood-related 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. These areas
are designated on city zoning maps with the :FP suffix.
for new development other than the issuance of a use permit
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; for a use permit it shall be the effective date of
approval of the use permit. The "actual start" for development other
than a substantial improvement means either the first placement of
permanent construction of a structure on a site, such as 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 sidewalks; 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 a 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.
means anything constructed or erected, except for fences,
the use of which requires a permanent location on the ground or attached
to something having a permanent location on the ground (Note: all
buildings are structures, but not all structures are buildings.)
means to place or leave in a location for preservation, later
use or disposal.
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% of the market value of the structure before
the damage occurred.
means any reconstruction, alteration, rehabilitation, addition,
or other proposed change of a structure, the cost of which equals
or exceeds 50% of the market value of the existing structure before
"start of construction" of the improvement; this term includes reconstruction,
rehabilitation, addition or repair of a structure which has incurred
"substantial damage," regardless of the actual amount of work performed.
The term "substantial improvement" does not however, include either:
Any project for improvement of a structure to correct existing
violations of 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
Any alteration, rehabilitation, repair addition or other change
of a "historic structure," provided that the work performed will not
preclude the structure's continued designation as an "historic structure."
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.
means the failure of a structure or development project to
be in full compliance with this chapter. A development project 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.
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.
means a lake, river, creek, stream, wash, arroyo, channel
or other topographic feature on or over which flood waters flow at
least periodically. Watercourse includes specifically designated areas
in which substantial flood damage may occur.
(O2003-12; O2009 7; O2009 8)
The Public Works Director of the City of Napa is hereby appointed
Floodplain Administrator to administer, implement, and enforce this
chapter and to grant or deny floodplain permits in accord with its
provisions. Specific duties and responsibilities of the Floodplain
Administrator shall include, but not be limited to, the following:
A.
Review
all applications for development within the floodplain to determine
that:
1.
The
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.
When base flood elevation data have not been provided in accordance with Section 17.38.020 of this chapter, 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 17.38.050 through 17.38.100.. Any such information shall be submitted to the City Council for its review and adoption.
C.
In
the event of alteration or relocation of a watercourse:
1.
Notify
adjacent communities and the California Department of Water Resources
prior to alteration or relocation of a watercourse.
2.
Submit
evidence of such notification to the Federal Insurance Administration,
Federal Emergency Management Agency.
3.
Assure
that the flood carrying capacity within the altered or relocated portion
of said watercourse is maintained.
D.
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 this section.
E.
F.
Take action to remedy violations of this chapter as specified in Section 17.38.020.
Any decision or determination made under this chapter by the
Floodplain Administrator may be appealed to the City Council by filing
a written appeal setting forth the reasons of the appeal accompanied
by the appropriate fee with the City Clerk not later than 10 calendar
days following the date of action from which such appeal is being
taken. If the tenth calendar day is a weekend or city holiday, the
deadline is extended to the next working day of the city. The City
Council shall consider the decision or determination de novo.
(O2003-12)
A.
No
development project may be approved by the City of Napa nor undertaken
by any person on property zoned :FP unless a floodplain permit is
first obtained from the Floodplain Administrator.
B.
Application
for a floodplain permit shall be made in a form acceptable to the
Floodplain Administrator, shall provide an indemnification that is
in the approved form and may include, but not be limited to: plans
drawn to scale showing the nature, location, dimensions, and elevation
of the area in question; existing or proposed structures, fill, storage
of materials or equipment, drainage facilities; and the location of
the forgoing. Specifically, the following information is required:
1.
Proposed elevation in relation to mean sea level, of the lowest floor (including basement) of all structures; or proposed elevation in relation to mean sea level to which any nonresidential structure will be floodproofed, if required in Section 17.38.060.
3.
Description
of the extent to which any watercourse will be altered or relocated
as a result of the proposed development.
4.
In
the case of a tentative parcel or subdivision map, the application
shall:
a.
Identify the special flood hazard area and the elevation of the base
flood on the tentative map;
b.
Show how any existing or buildings, structures or utilities will
comply with the development standards of this section;
c.
Identify the elevation of any existing structures, buildings or 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;
d.
Show how construction will minimize flood damage;
e.
Show how public utilities and facilities such as sewer, gas, electrical
and water systems located and constructed to minimize flood damage;
and
f.
Identify all drainage necessary to reduce exposure to flood hazards.
(O2003-12)
The following development standards shall be met on all lots
zoned :FP:
A.
All
new construction of structures shall be secured to a permanent foundation
system to prevent flotation, collapse, or lateral movement of the
structure resulting from hydrodynamic and hydrostatic loads, including
the effects of buoyancy.
B.
All
new construction and substantial improvement of structures shall be
constructed and designed:
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 as to
prevent water from entering or accumulating within the components
during conditions of flooding;
4.
With
adequate drainage paths around structures on slopes to guide floodwaters
around and away from structures; and
5.
In
compliance with FEMA Technical Bulletins 2-93, 3-93 and 7-93.
C.
All new construction or substantial improvement of residential buildings, shall have the lowest floor, including basement (See Section 17.38.030 definitions for "basement," "lowest floor," "new construction," "substantial damage" and "substantial improvement"), elevated to at least one foot above the base flood elevation as determined by this community and be designed so that fully enclosed areas below the lowest floor automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwaters. The minimum criteria for equalizing hydrostatic forces include 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 with the bottom of such opening no higher than one foot above grade and equipped with screens, louvers, valves or other coverings or devices which permit the automatic entry and exit of floodwaters.
Upon completion of the building, 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.
D.
All
new construction or substantial improvement of nonresidential buildings
shall either be elevated to conform with this section or together
with attendant utility and sanitary facilities:
1.
Be
flood proofed below an elevation one foot above the base flood elevation
so that the structure is watertight with walls substantially impermeable
to the passage of water; (See FEMA Technical Bulletins 3-93 and 7-93
for additional requirements);
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.
E.
All
new construction and substantial improvement of buildings with fully
enclosed areas below the lowest floor (excluding basements) that are
useable 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 meet or exceed the following minimum criteria:
1.
Be
certified by a registered professional engineer or architect; or
2.
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.
F.
All
new and replacement water supply, gas, electrical and sanitary sewage
systems shall be designed:
G.
All
manufactured homes placed or substantially improved within the special
flood hazard area and located:
1.
Outside
a manufactured home park or subdivision, or
2.
In
a new manufactured home park or subdivision, or
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 a level one foot
above the base flood elevation and be securely fastened to an adequately
anchored foundation system to resist flotation, collapse and lateral
movement.
H.
All
recreational vehicles placed on lots zoned :FP shall either:
1.
Be
on site for fewer than 180 consecutive days, and be fully licensed
and ready for highway use. A recreational vehicle is ready for highway
use only 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
(O2003-12)
The following additional development standards shall be met
in the flood evacuation portion of the :FP for residential developments
which consist of five or more units, including subdivisions or mixed
use projects with a residential development potential of five or more
units. The flood evacuation area is established by the city Public
Works Department consistent with the Health and Safety Element of
the General Plan.
Except as provided in subsection E of this section, a flood
evacuation plan, prepared by a registered civil engineer or architect
shall be required. Alternately, an approved hydraulic analysis, prepared
by a registered civil engineer, may be substituted for a flood evacuation
plan. A hydraulic analysis may also require an accompanying flood
evacuation plan, depending on the location of the property.
The flood evacuation plan and/or hydraulic analysis shall be
submitted to the Public Works Director for review and approval. In
determining the adequacy of flood evacuation plans, the Public Works
Director shall consider the existing and future street, drainage and
flood control facilities that could affect the proposed development
as well as the technical and economic feasibility of required flood
evacuation procedures and/or improvements. In determining the adequacy
of hydraulic analyses, the Public Works Director shall consider the
water surface elevation of the property and surrounding areas, flood
control facilities that could affect the proposed development, and
the location of the property in relationship to surrounding areas
of inundation. The Public Works Director shall determine if an accompanying
flood evacuation plan demonstrating a safe evacuation route shall
be submitted.
The minimum residential densities of the General Plan shall
not apply to residential developments of five or more units, including
potential units which could result from the subdivision of property,
when located on a property in the flood evacuation area.
A.
The
flood evacuation plan shall include the following:
1.
The
nature and extent of flooding and effect of such flooding on the occupants
of the proposed development and the ability to safely evacuate the
occupants from the premises in the event of a flood.
2.
Measures
needed to mitigate flood hazards and to assist the occupants of the
proposed development to safely evacuate in the event of a flood.
B.
The
flood evacuation plan shall be drawn to scale, and shall be of sufficient
size and clarity to show existing details and the nature and extent
of all proposed improvements. The plan shall include the following
information:
1.
Name
and address of owner;
2.
Name,
address, professional status, license number, and phone number of
the person who prepared the plan;
3.
Location
and assessor's parcel number of the proposed site;
4.
North
arrow, scale, and the name and location of the nearest public road
intersection;
5.
Existing
contours of the site, as well as finished contours to be achieved
by grading. Contours shall be sufficiently detailed to define the
topography over the entire site (generally at two-foot intervals);
6.
Location
of and elevation of the streets in the area of the proposed development
which would be used in the event of a flood evacuation;
7.
Location
of any buildings, structures, trees and other landscape features on
the property to remain, and the locations of any buildings, structures
or trees on adjacent property within 15 feet of adjoining property
lines;
8.
The
concept of the flood evacuation measures proposed and a plan showing
the construction details or other measures necessary to implement
the plan;
9.
Phasing
of proposed work, as appropriate.
C.
All
approved measures to mitigate flood hazards and to provide for the
safe evacuation of the occupants of the proposed development shall
become conditions of approval of the project. In addition all approved
flood evacuation measures shall be installed prior to the final clearance
of the building permit or concurrently with the installation of site
improvements in the case of a subdivision map.
D.
The
hydraulic analysis shall include the following:
2.
A
comprehensive list of data sources used for the analysis.
3.
Hydraulic
model(s) and related assumptions.
4.
Comparisons
of the water surface profile and site topography.
5.
Disclosure
of any limits to the analysis.
6.
Figures,
tables and plans sufficient to illustrate the water surface profiles
and water surface elevations, and areas of inundation in a 100-year
flood; and the boundaries of the area included in the analysis. Plans
should be to scale, and include street names, scale, and a north arrow.
7.
The
area of analysis should include the site to be developed and surrounding
areas to the nearest intersection that is outside of the city's identified
flood evacuation area to demonstrate a safe evacuation route from
the site.
E.
The
following projects are exempt from the requirements of this section:
1.
All
nonresidential development, unless such nonresidential development
includes residential development as part of a mixed use development,
in which case the requirement for a flood evacuation plan shall be
required;
2.
Residential
developments which consist of four or fewer units or subdivisions
with a development potential of four or fewer units;
3.
An
addition or expansion of less than 50% of the original total floor
area to an existing residential structure which, in the opinion of
the Public Works Director, involves no identifiable increase in the
flood evacuation hazards to the occupants of such a structure;
4.
Construction
within an existing structure which involves no expansion of the structure;
5.
Construction
proposed for a site where an approved flood evacuation plan and/or
hydraulic analysis has been prepared provided that the proposed development
conforms to the recommendations of the previously approved plan and/or
hydraulic analysis;
6.
A
lot line adjustment;
7.
A
use which involves no buildings or structures.
(O2003-12; O2006 6)
Floodways are areas specially designated within the special flood hazards area on the FIRM for the city (a copy of which is available in the office of the Public Works Director). Floodways are extremely hazardous areas due to the velocity of flood waters which carry debris, potential projectiles, and erosion potential. On those lots zoned :FP which are located in the floodway, the following provisions shall apply in addition to the general development standards and requirements of Section 17.38.060:
A.
New development projects are prohibited unless a floodway development analysis complying with Section 17.38.090 prepared by a registered professional engineer or architect is provided demonstrating that such new development shall not result in any increase in the base flood elevation during the occurrence of the base flood discharge.
B.
No
manufactured home shall be placed in a floodway, except in an existing
manufactured home development, mobile home park or mobile home subdivisions.
(O2003-12)
In all cases where a development project is proposed in the
floodway, a floodway development analysis, as described in this section
prepared by a registered professional engineer or architect is required.
The analysis shall supplement the existing data on the floodway by
adding one or more cross sections across the entire floodway, prepared
from field measurements. The number of cross sections required to
complete these analyses shall be determined by the Floodplain Administrator.
The minimum requirement shall be one cross section at the site of
the proposed development.
A.
Base
Case Analysis. Applicants shall prepare and submit for review a 100-year
water surface profile analysis of the entire length of the floodway
within the city utilizing the FEMA data and analysis method as amended,
without the imposition of any development which has occurred since
the FIS as amended. In the event that the applicant's project is in
close proximity to the city limits, the analysis shall extend into
the unincorporated area a sufficient distance as determined by the
analysis results, to demonstrate that there are no impacts beyond
the analysis limits. The requirement to be met is that there shall
be zero increase in the water surface area file for the entire length
of the floodway when compared to the FEMA data as amended.
B.
Cumulative
Analysis. Applicants shall prepare and submit for review a 100-year
water surface profile analysis, using an approved analysis method,
of the entire length of the floodway within the city utilizing updated
floodplain data that includes all floodway development which has occurred,
or which has been approved but not constructed since the FIS as amended.
In the event that the applicant's project is in close proximity to
the city limits, the analysis shall extend into the unincorporated
area a sufficient distance as determined by the analysis results,
to demonstrate that there are no impacts beyond the analysis limits.
The requirement to be met is that there shall be zero increase in
the water surface area file for the entire length of the floodway.
C.
Site Analysis. Applicants shall prepare and submit for review an analysis of the site, including adjacent property which may be impacted. The analysis shall include a floodway blockage before and after comparison and shall detail and analyze flood flow and velocity changes which will result from the proposed project. This analysis shall include an accurate topographic drawing of the proposed project, including structures or other blockages on adjacent properties. The drawing submitted for this purpose shall identify the flood flow patterns through the proposed project. Any adverse impacts on surrounding properties in the floodway shall be 100% mitigated. Specific compensatory action to increase flood carrying capacity must be proposed for any increase in blockage and for any adverse change in flood flow or velocity. Mitigation measures and compensatory actions proposed shall be verified by re-computing the 100-year water surface profile under subsections A and B above.
D.
Permanent
Record, Methodology and Limitations. All analyses shall, after review
and final modifications, be submitted in a form that will provide
a permanent record. The data and methodology approved by FEMA may
change over time. When performing the analyses required by these regulations,
the most current data and methodology approved by FEMA shall be utilized.
In areas of rapid ground elevation change, accurate topographic mapping
may reveal minor differences between actual conditions and the adopted
floodway. Regardless of such minor differences, no change in the adopted
floodway shall be made.
(O2003-12)
A.
The
variance procedures and 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 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 the adjacent parcels. The unique characteristic
must pertain to the land itself, not to the structure, its inhabitants,
or the property owners.
B.
The City Council needs 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 this chapter should be 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 detailed, contain multiple provisions that must be met before a variance can be properly granted and shall supersede the general variance procedures set forth in Chapter 17.64 (Variances) of this title. The criteria are designed to screen out those situations in which alternatives other than a variance are more appropriate.
C.
In
order to ensure accomplishment of the goals of this chapter, only
the City Council is authorized to act upon requests for a variance.
The City Council shall hold a public hearing on the application prior
to making a decision. In reviewing requests for variances, 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;
3.
Susceptibility
of the proposed facility and its contents to flood damage and the
effect of such damage on the existing 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;
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.
D.
The City Council may grant a variance for development 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 requirements of Sections 17.38.060 and 17.38.080 and 17.38.090, as applicable, have been fully considered. As the lot size increases, beyond one-half acre, the technical justification required for issuing the variance increases. In order to grant a variance, the City Council must find:
1.
The
applicant has made a showing of good and sufficient cause;
2.
The failure to grant the variance would result in exceptional "hardship" (as defined in Section 17.38.030 of this chapter) to the applicant;
3.
The
variance will not result in increased flood heights, additional threats
to public safety, i.e., anything which is injurious to the health
or safety of the entire community, a neighborhood or any considerable
number of people, extraordinary public expense, creation of a nuisance,
obstruction of free passage or use in the customary manner of any
navigable river, a conflict with existing laws or regulations or cause
fraud or victimization of the public or future owners who are unaware
of potential flood damage and high insurance rates;
4.
The
variance will afford the requested relief with the minimum deviation
from the requirements of this chapter;
5.
If
the property is within any mapped regulatory floodway, no increase
in flood levels during the base flood discharge would result from
the grant of the variance; and
6.
Such
conditions as are necessary to further the purposes of this chapter
have been imposed.
E.
The
City Council may grant a variance for development which is necessary
for the conduct of a functionally dependent use if the City Council
finds that the development:
F.
The
Floodplain Administrator shall ensure that any variance granted to
construct a structure below the base flood elevation includes a notice
that such construction will result in increased premium rates for
flood insurance significantly and shall record such notice in the
office of the Napa County Recorder.
G.
The
Floodplain Administrator shall maintain a record of all variance actions
and report such variances issued in its biennial report submitted
to the Federal Insurance Administration and Federal Emergency Management
Agency.
(O2003-12)
