HomeMy WebLinkAboutMINUTES - 12041990 - 1.23 1, R3
Ordinance No. 90- 118
(FLOODPLAIN MANAGMENT ORDINANCE)
The Contra Costa County Board of Supervisors ordains as follows
(omitting the parenthetical footnotes from the official text of
the enacted or amended provisions of the County Ordinance Code) :
SECTION I. SUMMARY. This ordinance provides floodplain
management requirements in flood hazard areas of Contra Costa
County.
SECTION II. Chapter 82-28 is added to the County Ordinance Code
to read:
CHAPTER 82-28 FLOODPLAIN MANAGEMENT ORDINANCE
ARTICLE 82-28 .2 GENERAL
82-28.202 STATUTORY AUTHORIZATION. This ordinance is designed
to promote the public health, safety and general welfare of the
citizens of Contra Costa County and is enacted pursuant to the
authority of United States Code, Title 43, Chapter 50 (42 U.S.C.
§§4001-4128; see especially 42 U.S.C. §4022) ; Government Code
Sections 25120-25132; Health & Safety Code Section 450; and
California Constitution, Article XI, Section 7.
(Ords. 90-118, 88-50, 87-45. )
82-28.204 FINDINGS OF FACT. (1) The flood hazard areas of
Contra Costa County 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.
(2) These flood losses are caused by inadequate drainage
facilities and the cumulative effect of obstructions in areas of
special flood hazards which increase flood heights and
velocities. These losses may result when structures are
inadequately anchored. These flood losses may result in damage
to property in other areas. Structures that are inadequately
floodproofed, elevated or otherwise protected from flood damage
also contribute to the flood loss.
90-118
(3) Contra Costa County has experienced serious flooding which
has resulted in substantial property damage and the potential for
loss of life. Adoption of a legally enforceable floodplain
management ordinance which fully complies with the recently
revised rules of the National Flood Insurance Program
administered by the Federal Emergency Management Administration
will allow the County of Contra Costa to continue its
participation in said program. The continued participation of
the County in the National Flood Insurance Program is desirable
and promotes the public health, safety, and welfare in that it
provides insurance and federal assistance in the event of
flood(s ) within the County's jurisdiction. In the absence of
such insurance, the County's vulnerability to damage and loss
resulting from flood events, may be substantial and potential
flood damage represents an immediate threat to the public health,
safety and welfare.
(Ords. 90-1.1a, 88-50, 87-45. )
82-28.206 STATEMENT OF PURPOSE. It is the purpose of this
ordinance to promote the public health, safety, and general
welfare, and to minimize public and private losses due to flood
conditions in specific areas by provisions designed (1) To
protect human life and health;
(2) To minimize expenditure of public money for costly flood
control projects;
(3) To minimize the need for rescue and relief efforts
associated with flooding and generally undertaken at the expense
of the general public;
(4 ) To minimize prolonged business interruptions;
(5 ) To minimize damage to public facilities and utilities such
as water and gas mains, electric, telephone and sewer lines,
streets and bridges located in areas of special flood hazard;
(6 ) To help maintain a stable tax base by providing for the
use and development of areas of special flood hazard subject to
review by permit and flood damage reduction standards so as to
minimize future flood blight areas;
(7 ) To provide to the general public, upon request,
information regarding special flood hazard areas in the
unincorporated areas of the County; and
(8) To clearly establish that those who occupy the areas of
special flood hazard should assume responsibility for their
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ordinance 90- 11.8
actions and the losses they may suffer.
(Ords. 90-118 , 88-50, 87-45 . )
82-28.208 METHODS OF REDUCING FLOOD LOSSES. In order to
accomplish its purpose, this ordinance includes methods and
provisions for (1) Restricting or prohibiting uses which are
dangerous to health, safety, and property due to water or erosion
hazards, or which result in damaging increases in erosion, flood
heights or velocities;
(2) Requiring that uses vulnerable to floods, including
facilities such as utilities which serve such uses, be protected
against flood damage at the time of initial construction;
(3) Requiring that the design of streets and public access
facilities include consideration of accessibility under the base
flood conditions for emergency service vehicles and any rescue
and relief operations;
(4 ) Controlling the alteration of natural floodplains, stream
channels, and natural protection barriers, which help accommodate
or channel flood waters;
(5 ) Controlling filling, grading, dredging, and other
development which may increase flood damage; and,
(6 ) Preventing or regulating the construction of flood
barriers which will unnaturally divert flood waters or which may
increase flood hazards in other areas .
(7) Requiring orderly development of drainage facilities
within watershed areas as development occurs .
(Ords . 90-__L14 88-50, 87-45 . )
ARTICLE 82-28 .4 DEFINITIONS
Unless specifically defined below, words or phrases used in this
ordinance shall be interpreted so as to give them the meaning
they have in common usage and to give this ordinance its most
reasonable application.
82-28.402 "Appeal" means a request for a review of the
Floodplain Administrator's interpretation of any provision of
this ordinance or a request for a variance.
(Ords . 90-118 , 88-50, 87-45. )
82-28.404 "Area of shallow flooding" means a designated A0. AH
or VO Zone on the Flood Insurance Rate Map (FIRM) . The base
flood depths range from one to three feet; a clearly defined
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Ordinance 90-118
channel does not exist; the path of flooding is unpredictable and
indeterminate; and velocity flow may be evident.
(Ords . 90- 118, 88-50, 87-45. )
82-28.406 "Base flood" means the flood having a 1 percent chance
of being equalled or exceeded in any given year (also called the
"100-year flood" ) .
(Ords. 90-118, 88-50, 87-45. )
82-28.408 "Basement" means any area of the building having its
floor subgrade (below ground level) on all sides.
(Ords. 90-118, 88-50, 87-45. )
82-28.410 "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 and which is
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 ten and no more
than twenty 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.
(Ords . 90- 118,, 88-50, 87-45 . )
82-28.412 "Coastal high hazard area" is the area subject to high
velocity waters, including coastal and tidal inundation or
tsunamis. The area is designated on a Flood Insurance Rate Map
(FIRM) as Zone VI-V30, VE or V.
(Ords. 90-118, 88-50, 87-45. )
82-28.414 "Development" 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.
(Ords. 90-118, 88-50, 87-45. )
82-28.416 "Existing manufactured home park or subdivision" means
a manufactured home park for which the construction of facilities
for servicing the lot on which the manufactured homes are to be
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Ordinance 90- 118
affixed (including, at a minimum, the installation of utilities,
either final site grading or the pouring of concrete pads, and
the construction of streets) is completed on or before the
effective date of this ordinance.
(Ords . 90-118, 88-50, 87-45 . )
82-28.418 "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, either final site grading or pouring of concrete
pads, or the construction of streets.
(Ords. 90-118 , 88-50, 87-45. )
82-28.420 "Flood or flooding" means a general and temporary
condition of partial or complete inundation of normally dry land
areas from (1) the overflow of flood waters, (2 ) the unusual and
rapid accumulation or runoff of surface waters from any source,
and/or (3) the collapse or subsidence �of land along the shore of
a lake or other body of water as a result of erosion or
undermining caused by waves or currents of water exceeding
anticipated cyclical levels or suddenly caused by an unusually
high water level in a natural body of water, accompanied by a
severe storm, or by an unanticipated .force of nature, such as
flash flood or an abnormal tidal surge, or by some similarly
unusual and' unforeseeable event which results in flooding as
defined in this definition.
(Ords . 90- 118,, 88-50,87-45. )
82-28.422 "Flood Boundary and Floodway Man" means the official
map described in Section 82-28 .604 on which the Federal Emergency
Management Agency or Federal Insurance Administration has
delineated both the areas of flood hazard and the floodway.
(Ords. 90-1_U, 88-50, 87-45. )
82-28.424 "Flood Insurance Rate Map (FIRM) " means the 'official
. map described in Section 82-28 .606 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.
(Ords . 90-1. $, 88-50, 87-45. )
82-28.426 "Flood Insurance Study" means the official report
described in Section 82-28.604 provided by the Federal Insurance
Administration that includes flood profiles, the FIRM, the ,Flood
Boundary and Floodway Map, and in some areas, the water surface
elevation of the base flood.
(Ords. 90-1.U, 88-50, 87-45. )
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Ordinance 90- 118
82-28.428 "Floodplain or flood prone area" means any land area
susceptible to being inundated by water from any source (see
definition of "flooding" ) .
(Ords. 90-118, 88-50, 87-45. )
82-28.430 "Floodplain management" means the operation of an
overall program of corrective and preventive measures for
reducing flood damage, including but not limited to emergency
preparedness plans, flood control works and floodplain management
regulations.
(Ords. 90-118, 88-50, 87-45. )
82-28.432 "Floodplain management regulations" means zoning
ordinances, subdivision regulations, building codes, health
regulations, special purpose ordinances (such as floodplain
ordinance, grading ordinance and erosion control ordinance) and
other applications of police power. The term describes such
state or local regulations in any combination thereof, which
provide standards for the purpose of flood damage prevention and
reduction.
(Ords. 90-118, 88-50, 87-45. )
82-28.434 "Floodplain permit" means a permit required of all
development which occurs in any area designated by FEMA as a
Floodway, Coastal High Hazard Area, Zone A, A0, Al-A30, A99, AH,
V, V0, or V1-V30, and other areas adopted by the Zoning
Administrator.
(Ords . 90-118 , 88-50, 87-45 . )
82-28.436 "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 .
(Ords. 90-118, 88-50, 87-45 . )
82-28.438 "Floodway" means the channel of a river or .other
watercourse and the adjacent land areas that must be reserved in
order to discharge the base flood without cumulatively increasing
the water surface elevation more than one foot. Also referred to
as "Regulatory floodway. "
(Ords. 90-118, 88-50, 87-45. )
82-28.440 "Freeboard" means a factor of safety usually expressed
in feet above a flood level for purposes of floodplain management.
"Freeboard" tends to compensate for the many unknown factors that
could contribute to flood heights greater than the height
calculated for a selected size flood and floodway conditions, such
as wave action,, bridge openings, and the hydrological effect of
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Ordinance 90- 118
urbanization of the watershed.
(Ords. 90- 118, 88-50, 87-45 . )
82-28.442 "Functionally dependent use" means a use which cannot
perform its intended purpose unless it is located or carried out in
close proximity to water. The term includes only docking
facilities, port facilities that are necessary for the loading and
unloading of cargo or passengers, and ship building and ship repair
facilities, but does not include long-term storage or related
manufacturing facilities .
(Ords. 90- 118, 88-50, 87-45. )
82-28.444 "Highest adjacent grade" means the highest natural
elevation of the ground surface prior to construction next to the
proposed walls of a structure.
(Ords . 90-118, 88-50, 87-45. )
82-28.446 "Lowest floor" means the lowest floor of the lowest
enclosed area (including basement) . An unfinished or flood
resistant enclosure, usable solely for parking of vehicles,
building access or storage in an area other than a basement area is
not considered a building's lowest floor; provided, that such
enclosure is not built so as to render the structure in violation
of the applicable non-elevation design requirements of this
ordinance.
(Ords . 90-118, 88-50, 87-45 . )
82-28.448 "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
connected to the required utilities. For floodplain management
purposes the term "manufactured home" also includes park trailers,
travel trailers and other similar vehicles placed on a site for
greater than 180 consecutive days.,
(Ords . 90- 118, 88-50, 87-45. )
82-28.450 "Manufactured home park or subdivision" means a parcel
(or contiguous parcels) of land divided into two or more
manufactured home lots for sale or rent.
(Ords . 90- 118, 88-50, 87-45. )
82-28.452 "Mean sea level" means, for purposes of the National
Flood Insurance Program, the National Geodetic Vertical Datum
(NGVD) of 1929 or other datum, to which base flood elevations shown
on a community's Flood Insurance Rate Map are referenced.
(Ords. 90- 118, 88-50, 87-45. )
82-28.454 "New construction" means, for floodplain management
purposes, structures for which the "start of construction"
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Ordinance 90-118
commenced on or after the effective date of a floodplain management
regulation adopted by this community.
(Ords . 90-118 , 88-50, 87-45. )
. 82-28.456 "One hundred year flood" or "100-year flood" means a
flood which has a one percent annual probability of being equalled
or exceeded. It is identical to the "base flood, " which will be
the term used throughout this ordinance.
(Ords. 90-118 , 88-50, 87-45. )
82-28.458 "Person" means an individual or his agent, firm,
partnership, association or corporation, or agent of the
aforementioned groups, or this state or its agencies or political
subdivisions.
(Ords . 90-118 , 88-50, 87-45. )
82-28.460 "Remedy a violation" means to bring the structure or
other development into compliance with State or local floodplain
management regulations, or, if this is not possible, to reduce the
impacts of its noncompliance. Ways that impacts may be reduced
include protecting the structure or other affected development from
flood damages, implementing the enforcement provisions of the
ordinance or otherwise deterring future similar violations, or
reducing Federal financial exposure with regard to the structure or
other development.
(Ords . 90-118 , 88-50, 87-45. )
62-28.462 "Riverine" means relating to, formed by, or resembling a
river including tributaries, streams and brooks .
(Ords. 90-118 , 88-50, 87-45 . )
62-28.464 "Sand dunes" means naturally occurring accumulations of
sand in ridges or mounds landward of the beach.
(Ords . 90-118 , 88-50, 87-45. )
82-28.466 "Special flood hazard area (SFHA) " means an area having
special flood or flood-related erosion hazards, and shown on an
FHBM or FIRM as Zone A, AO, Al-30, A99, AH, VO, V1-30 or V.
(Ords. 90-118 , 88-50, 87-45. )
82-28.468 "Start of Construction" includes substantial
improvement, and means the date the building permit was issued,
provided the actual start of construction, repair, reconstruction,
placement, or other improvement was within 180 days of the permit
date. The actual start means either the first placement of
permanent construction of a structure on a site, such as the
pouring of slab or footings, the installation of piles, the
construction of columns, or any work beyond the stage of
excavation; or the placement of a manufactured home on a
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Ordinance 90- 118
foundation. Permanent construction does not include land
preparation, such as clearing, grading and filling; nor does it
include the installation of streets and/or walkways; nor does it
include excavation for a basement, footings, piers, or foundations
or the erection of temporary forms; nor does it include the
installation on the property of accessory buildings, such as
garages or sheds not occupied as dwelling units or not part of the
main structure.
(Ords . 90-118 , 88-50, 87-45. )
82-28.470 "Structure" means a walled and roofed building,
including a gas or liquid storage tank, that is principally above
ground, as well as a manufactured home.
.(Ords . 90-118 ,, 88-50, 87-45. )
82-28.472 "Substantial i=rovemtent" means any repair,
reconstruction, or improvement of a structure, the cost of which
equals or exceeds 50 percent of the market value of the structure
either (1) before the improvement or repair is started; or
(2) if the structure has been damaged, and is being restored, before
the damage occurred.
For the. purposes of this definition "substantial improvement" is
considered to occur when the first alteration of any wall, ceiling, floor,
or other structural part of the building commences, whether or not that
alteration affects the external dimensions of the structure. The term
does not, however, include either:
(1) any project for improvement of a structure to comply with existing
State or local health, sanitary, or safety code specifications
which are solely necessary to assure safe living conditions; or
(2 ) any alteration of a structure listed on the National Register of
Historic Places or a State Inventory of Historic Places .
(Ords . 90-_112, 88-50, 87-45. )
82-28.474 "Variance" means a grant of relief from the requirements
of this ordinance which permits construction in a manner that would
otherwise be prohibited by this ordinance.
(Ords. 90- 118, 88-50, 87-45. )
82-28.476 "Violation" means the failure of a structure or other
development to be fully compliant with the community's floodplain
management regulations. A structure or other development without
the elevation certificate, other certifications, or other evidence
of compliance required in this ordinance is presumed to be in
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Ordinance 90- 118
violation until such time as that documentation is provided.
(Ords . 90- 118, 88-50, 87-45 . )
ARTICLE 82-28 .6 GENERAL PROVISIONS
82-28.602 LANDS TO WHICH THIS ORDINANCE APPLIES. This ordinance
shall apply to all areas of special flood hazards within the
jurisdiction of Contra Costa County, as shown on the maps described
in Section 82-28 .604.
(Ords . 90-118, 88-50, 87-45. )
62-28.604 BASIS FOR ESTABLISHING THE AREAS OF SPECIAL FLOOD
HAZARD. The areas of special flood hazard have been identified by
the Federal Emergency Management Agency or the Federal Insurance
Administration in a scientific and engineering report entitled
"Flood Insurance Study for Contra Costa County, Unincorporated
Areas, " dated July 16, 1987, with accompanying Flood Insurance Rate
Map and Flood Boundary and Floodway Map of same date, which study
and maps are hereby adopted by reference and declared to be a part
of this ordinance. This Flood Insurance Study and accompanying
maps are on file at the Contra Costa County Community Development
Department, 4th Floor North Wing, 651 Pine Street, Martinez. This
Flood Insurance Study is the minimum area of applicability of this
ordinance and may be supplemented by studies for other areas which
allow implementation of this ordinance and which are recommended
to the Zoning Administrator by the Floodplain Administrator.
Within the areas of special flood hazard identified in the Flood
Insurance Study, accompanying maps and supplemental studies,
freeboard is required. In the San Francisco Bay Delta Estuarine
Region, two feet of freeboard is required. In all other
unincorporated areas of the County, one foot of freeboard is
required.
(Ords. 90-118, 88-50, 87-45. )
82-28.606 COMPLIANCE. No structure or land shall hereafter be
constructed, located, extended, converted, or altered without full
compliance with the terms of this ordinance and other applicable
regulations. Violations of the requirements (including violations
of conditions and safeguards established in connection with
conditions ) shall constitute an infraction punishable as provided
in Government Code Section 25132 and as set forth in Division 14
of this Code and Section 82-2.006 of this Division. Nothing herein
shall prevent the Contra Costa County Board of Supervisors from
taking such lawful action as is necessary to prevent or remedy any
violation.
(Ords . 90-118, 88-50, 87-45. )
82-28.608 ABROGATION AND GREATER RESTRICTIONS. This ordinance is
not intended to repeal, abrogate, or impair any statutes, laws, or
regulations. However, where this ordinance and another statute,
law, or regulation conflict or overlap,
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Ordinance 90- 118
whichever imposes the more stringent restrictions shall prevail.
(Ords . 90-118 , 88-50, 87-45. )
82-28.610 INTERPRETATION. In the interpretation and application
of this ordinance, all provisions shall be: (1) Considered as
minimum requirements;
(2) Liberally construed in favor of the governing body; and,
(3) Deemed neither to limit nor repeal any other powers
granted under state statutes.
(Ords. 90-118 , 88-50, 87-45. )
82-28.612 WARNING AND DISCLAIMER OF LIABILITY. The degree of
flood protection required by this ordinance 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 ordinance does not imply that land outside
the areas of special flood hazards or uses permitted within such
areas will be free from flooding or flood damages. This ordinance
shall not create liability on the part of Contra Costa County, any
officer or employee thereof, or the Federal Insurance
Administration, for any flood damages that result from reliance on
this ordinance or any administrative decision lawfully made
thereunder.
(Ords . 90-_118, 88-50, 87-45. )
82-28.614 SEVERABILITY. This ordinance and the various parts
thereof are hereby declared to be severable. Should any section of
this ordinance be declared. by the courts to be unconstitutional or
invalid, such decision shall not affect the validity of the
ordinance as a whole, or any portion thereof other than the section
so declared to be unconstitutional or invalid.
(Ords. 90-j. a, 88-50, 87-45. ) '
ARTICLE 82-28.8 ADMINISTRATION
82-28.802 ESTABLISHMENT OF FLOODPLAIN PERMIT. A Floodplain Permit
shall be obtained from the Contra Costa County Community
Development Department before construction, a grading permit,
building permit, variance permit, land use permit or development
permit is issued, and, prior to filing of a Final Map or a Parcel
Map, or development begins within any area of special flood hazards
established in Section 82-28.604 . Application for a Floodplain
Permit shall be made on forms furnished by the Floodplain
Administrator, in the Community Development Department of Contra
Costa County and may include, but not be limited to: plans in
triplicate drawn to scale showing the nature, location, dimensions,
Ordinance 90- 118
a
and elevation of the area in question; existing or proposed
structures, fill, storage of materials, drainage facilities; and
the location of the foregoing. Specifically, the following
information is required (1) Proposed elevation in relation to
mean sea level, of the lowest floor (including basement) of all
structures; in Zone AO or V0, elevation of highest adjacent grade
and proposed elevation of lowest floor of all structures .
(2) Proposed elevation in relation to mean sea level to which
any structure will be floodproofed;
(3) All appropriate certifications listed. in Section 82- ,
28.806(4) of this ordinance; and
(4 ) Description of the extent to which any watercourse will be
altered or relocated as a result of proposed development.
(Ords . 90- 118, 88-50, 87-45. )
82-28.804 DESIGNATION OF THE FLOODPLAIN ADMINISTRATOR. The
Director of the Community Development Department is the Floodplain
Administrator but may designate a person under his supervision to
administer and implement this ordinance by granting or denying
Floodplain Permits in accordance with its provisions .
(Ords. 90-118, 88-50, 87-45 . )
87-28.806 DUTIES AND RESPONSIBILITIES OF THE FLOODPLAIN
ADMINISTRATOR. The Floodplain Administrator may ( 1 ) Review
Permits, including
(a) Review of all Floodplain Permits to determine that the permit
requirements of this ordinance have been satisfied;
(b) Review of written statements required to be submitted by each
applicant that all other required State and Federal permits have been
obtained;
(c) Review of Floodplain Permits for compliance with Federal
Emergency Management Agency requirements for elevation of structures above
the floodplain plus freeboard.
(d) Review of Floodplain Permits for compliance with Federal
Emergency Management Agency requirements so that the proposed development
does not adversely affect the carrying capacity of the floodway. For
purposes of this ordinance, "adversely affect" means that the cumulative
effect of the proposed development, when combined with all other existing.
and anticipated development, will not increase the water surface elevation
of the base flood more than one foot at any point.
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Ordinance 90- 118
(2) Use Other Base Flood Data. When base flood- elevation data has not
been provided in accordance with Section 82-28 .604, the Floodplain
Administrator may obtain, review, and reasonably utilize any base flood
elevation and floodway data available from a Federal, State, or other
source, in order to administer Article 82-28.10.
(3.) Notify Agencies of Watercourse Relocation. When a
watercourse is to be altered or relocated, the Floodplain
Administrator may notify the Contra Costa County Flood Control and
Water Conservation District, adjacent communities and the
California Department of Water Resources prior to such alteration
or relocation, send copies of such notice to the Federal Insurance
Administration, and require that the flood carrying capacity of the
altered or relocated portion of said watercourse be maintained.
(4 ) Maintain Records. The Floodplain Administrator shall be
provided the following records:
(a) The certification required in Section 82-28 .1002(3) (a)
(floor elevations) ;
(b) The certification required in Section 82-28.1002( 3) (b)
(elevations in areas of shallow flooding) ;
(c) The certification required in Section 82-28. 1002(3) (c)
(iii) (elevation of floodproofing of nonresidential structures) ;
(d) The certification required in Section 82-28 . 1002(3) (d)
(i) or 82-28 . 1003(3) (d) (ii) . (wet floodproofing standard) ;
(e) The certified elevation required in Section 82-
28 . 1006 (2-) (subdivision standards) ;
(f ) The certification required in Section 82-28 .1010(1 )
(floodway encroachments) ; and
(g) The information required in Section 82-28 . 1012(6)
(coastal construction standards) .
5. Determination of Boundaries. The Floodplain Administrator
may make interpretations where needed, as to the exact location of
the boundaries of the areas of special flood hazards (e.g. ,
conflicts between mapped boundaries 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
Article 82-28.12.
6 . Remedy Violations . The Floodplain Administrator may take
appropriate action to remedy violations of this ordinance, as
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specified in Section 82-28 .606, with the assistance of the Code
Enforcement Officer.
(Ords . 90- 118, 88-50, 87-45. )
ARTICLE 82-28.10 PROVISIONS FOR FLOOD HAZARD REDUCTION
82-28.1002 STANDARDS OF CONSTRUCTION. In all areas .of special
flood hazards, the following standards apply: (1) Anchoring.
(a) All new construction and substantial improvements shall be
anchored to prevent flotation, collapse or lateral movement of the
structure resulting from hydrodynamic and hydrostatic loads, including
the effects of buoyancy.
(b) All manufactured homes shall meet the anchoring standards
of Section 82-28 . 1008.
(2) Construction Materials and Methods .
(a) All new construction and substantial improvements shall be
constructed with materials and utility equipment resistant to flood
damage.
(b) All new construction and substantial improvements shall be
constructed using methods and practices that minimize flood damage.
(c) All new construction and substantial improvements shall be
constructed with electrical, heating, ventilation, plumbing, and air
conditioning equipment and other service facilities that are designed
and/or located so as to prevent water from -entering or accumulating
within the components during conditions of flooding.
(d) In Zones AH, AO or V0, adequate drainage paths shall be
required around structures on slopes to guide flood waters around and
away from proposed structures.
(3) Elevation and Floodproofing
(a) New construction and substantial improvement of any
structure shall have the lowest floor, including basement, elevated to
or above the base flood elevation plus required freeboard. In the San
Francisco Bay Delta Estuarine Region, two feet of freeboard is required.
In all other unincorporated areas of the County, one foot of freeboard
is required. Nonresidential structures shall meet the standards in
Section 82-28.1002(3) (c) . 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
community building inspector to be properly elevated. Such
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Ordinance 90-218
certification or verification shall be provided to the Floodplain
Administrator.
(b) New construction and substantial improvement of any
structure in Zone AH, AO or VO shall have the lowest floor,
including basement, elevated above the highest adjacent grade at
least as high as the depth number specif ied in feet on the FIRM
plus required freeboard, or at least two feet if no depth number
is specified. In the San Francisco Bay Delta Estuarine Region, two
feet of freeboard is required. In all other unincorporated areas
of the County, one foot of freeboard is required. Nonresidential
structures shall meet the standards in Section 82-28. 1002(3) (c) .
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 community
building inspector to be properly elevated. Such certification or
verification shall be provided to the Floodplain Administrator.
(c) Nonresidential construction shall either be elevated
in conformance with Section 82-28. 1002(3) (a) or (b) or together
with attendant utility and sanitary facilities:
(i) Be floodproofed so that below the base flood
level _ the structure is watertight with walls substantially
impermeable to the passage of water;
. (ii) Have structural components capable of
resisting hydrostatic and hydrodynamic loads and effects of
buoyancy; and
(iii) Be certified by a registered professional
engineer or architect- that the standards of this subsection
are satisfied. Such certification shall be provided to the
Floodplain Administrator.
(d) For all new construction and substantial
improvements all fully enclosed areas below the lowest floor . that
are subject to flooding shall be designed to automatically equalize
hydrostatic flood forces on exterior walls by allowing for the
entry and exit of floodwaters. Designs for meeting this
requirement must either be certified by a registered professional
engineer or architect or meet or exceed the following minimum
criteria:
(i) Have a minimum of two openings with 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
floodwaters; or
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Ordinance 90-118
(ii) Be certified to comply with a local floodproofing
standard approved by the Federal Insurance Administration.
(6 ) Manufactured homes shall also meet the standards in Section 82-
28 .1008 .
(Ords. 90- 118, 88-50, 87-45 . )
82-28.1004 STANDARDS FOR UTILITIES (1) All new and replacement water
supply and sanitary sewage systems shall be designed to minimize or
eliminate infiltration of flood waters into the system and discharge from
systems into flood waters.
(2) On-site waste disposal systems shall be located to avoid
impairment to them or contamination from them during flooding.
(3) On-site water supply systems shall be located to avoid impairment
or contamination during a flood.
(Ords. 90-118, 88-50, 87-45 . )
82-28.1006 STANDARDS FOR SUBDIVISIONS (1) All Tentative Maps for
preliminary subdivision proposals shall identify the flood hazard area and
the elevation of the base flood.
(2 ) All final subdivision improvement plans will provide the
elevation of proposed structure(s) , pads and streets .. If the site is
filled above the base flood, the final pad elevations shall be certified
by a registered professional engineer or surveyor and provided to the
Floodplain Administrator.
(3) All subdivision proposals shall be consistent with the need to
minimize flood damage.
(4 ) All subdivision proposals shall have public utilities and
facilities such as road, sewer, gas, electrical and water systems located
and constructed to minimize flood damage.
(5) All subdivisions shall provide adequate drainage to reduce
exposure to flood hazards.
(Ords . 90-11R, 88-50, 87-45 . )
82-28.1008 STANDARDS FOR MANUFACTURED HOMES. (1) All manufactured homes
to be placed or substantially improved within Zones Al-30, and AH, as
shown on the study and maps described in Section 82-28 .604 shall:
(a) Be elevated on a permanent foundation such that the lowest
floor of the manufactured home is at or above the base flood elevation,
plus required freeboard. In the San Francisco Bay Delta Estuarine Region,
two feet of freeboard is required. In all other unincorporated areas of
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Ordinance 90- 118
the County, one foot of freeboard is required.
(b) Be securely anchored to an adequately anchored foundation
system to resist flotation, collapse or lateral movement.
(2) Section 82-28. 1008(1 ) shall apply to:
(a) Manufactured homes to be placed or substantially improved in
an expansion to an existing manufactured home park or subdivision;
(b) Manufactured homes to be placed or substantially improved
outside of a manufactured home park or subdivision; and
(c) Manufactured homes to be placed in a manufactured home park
or subdivision established on or after the effective date of this
ordinance.
(3) Section 82-28 . 1008(1) (a) shall not apply to manufactured homes to
be placed or substantially improved in an existing manufactured home park
or subdivision, except where the repair, reconstruction or improvement of
the streets, utilities and pads equals or exceeds fifty (50) percent of
the streets, utilities and pads before the repair, reconstruction or
improvement has commenced.
(Ords . 90-_114 88-50, 87-45. )
82-28.1010 FIMDWAYS. Within areas of special flood hazard
established in Section 82-28.604 there are areas designated as
floodways . A floodway is an extremely hazardous area due to the
velocity of flood waters which carry debris, potential projectiles,
and erosion potential. Encroachments, including fill, new
construction, substantial improvements, and other developments are
not allowed in floodways unless certification by a registered
professional engineer or architect is provided demonstrating that
such encroachments shall not result in any increase in flood levels
during the occurrence of the base flood discharge. Allowed new
construction and improvements shall comply with all applicable
flood hazard reduction provisions of Article 82-28 . 10.
(Ords .. 90- 118, 88-50, 87-45. )
..82-28.1012 COASTAL HIGH HAZARD AREAS. Within coastal high hazard
areas established in Section 82-28 .604, the following standards and
provisions shall apply:
(1 ) All new construction and substantial improvements shall be
elevated on adequately anchored pilings or columns and securely
anchored to- such pilings or columns so that the lowest horizontal
portion of the structural members of the lowest floor (excluding
the pilings or columns) is elevated to or above the base flood
elevation plus required freeboard. In the San Francisco Bay Delta
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Ordinance 90- 118
Estuarine Region two fee of freeboard is required. In all other
unincorporated areas of the County, one foot of freeboard is
required.
(2) All new construction shall be located on the landward side
of the reach of mean high tide.
(3) All new construction and substantial improvements shall
have the space below the lowest floor free of obstructions or
constructed with breakaway walls . Such temporarily enclosed space
shall not be used for human habitation.
(4) Fill shall not be used for structural support of
buildings .
(5) Man-made alteration of sand dunes which would increase
potential flood damage is prohibited.
(6 ) The Floodplain Administrator shall be provided the
following records:
(a) Certification by a registered engineer or architect
that a proposed structure complies with Section 82-28. 101.2(1 ) .
(b) The elevation (in relation to mean sea level) of the
bottom of the lowest structural member of the lowest floor
(excluding pilings or columns) of all new and substantially
improved structures and identification of basements.
(Ords . 90-118 , 88-50, 87-45. )
ARTICLE 82-28 . 12 VARIANCE PROCEDURE
82-28.1202 APPEAL BOARD (1) The Zoning Administrator of Contra
Costa County shall hear and decide appeals and requests for
variances from the requirements of this ordinance.
. (2) The Zoning Administrator 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 ordinance.
(3) In passing upon such applications, the Zoning
Administrator shall consider all technical evaluations, all
relevant factors and standards -as specified in this ordinance, and
shall also consider the following factors:
(a) The danger that materials may be swept onto other
lands to the injury of others;
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Ordinance 90- 118
(b) The danger of life and property due to flooding or
erosion damage;
(c) The susceptibility of the proposed facility and its
contents to flood damage and the effect of such damage on the
individual owner;
(d) The importance of the services provided by the
proposed facility to the community;
(e) The necessity to the facility of a waterfront
location, where applicable;
(f) The availability of alternative locations for the
proposed use which are not subject to flooding or erosion damage;
(g) The compatibility of the proposed use with existing
and anticipated development;
(h) The relationship of the proposed use to the
comprehensive plan and floodplain management program for that area;
(i) The safety of access to the property in time of flood
for ordinary and emergency vehicles;
( j ) The expected heights, velocity, duration, rate of
rise, and sediment transport of the flood waters expected at the
site; and,
(k) The costs of providing governmental services during
and after flood conditions, including maintenance and repair of
public utilities and facilities such as sewer, gas, electrical, and
water system, and streets and bridges.
(4 ) Generally, variances may be issued for new construction
and substantial improvements 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,
provided section 82-28. 1202(3) factors have been fully considered.
As the lot size increases beyond one-half acre, the technical
justification required for issuing the variance increases.
(5) Upon consideration of the factors of Section 82-28. 1202(3)
and the purposes of this ordinance, the Zoning Administrator may
attach such conditions to the granting of variances as he or she
deems necessary to further the purposes of this ordinance.
(6 ) Appeals from Zoning Administrator decisions may be made in
the time and manner provided in Contra Costa County Ordinance Code
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Ordinance 90-118
` Article 26-2.24 to the Planning Commission and Board of Supervisors
upon payment of prescribed fees. '
(7) The Floodplain Administrator may maintain the records of
all appeal actions and report any variances to the Federal
Insurance Administration upon request.
(Ords. 90- 118, 88-50, 87-45. )
82-28.1204 CONDITIONS FOR VARIANCES (1) Variances may be issued
for the reconstruction, rehabilitation or restoration of structures
listed in the National Register of Historic Places or the State
Inventory of Historic Places, without regard to the procedures set
forth in the remainder of this section.
(2) Variances shall not be issued within any designated
floodway if any increase in flood levels during the base flood
discharge would result.
(3) Variances shall only be issued upon a determination that
the variance is the minimum necessary, considering the flood
hazard, to afford relief.
(4 ) Variances shall only be issued upon:
(a) A showing of good and sufficient cause, taking into
consideration the factors set forth in Section 82-28. 1202(3) ;
(b) A determination that failure to grant the variance
would result in exceptional hardship to the applicant; and
(c) A determination that the granting of a variance will
not result in increased flood heights, additional threats to public
safety, extraordinary public expense, the creation of a nuisance,
fraud or victimization of the public, or conflict with existing
local laws or ordinances .
(5) Variances may be issued for new construction and substantial
improvements and for other development necessary for the conduct of a
functionally dependent use provided that the provisions of Section 82-
28.1204 (1) - (4 ) are satisfied and that the structure or other
development is protected by methods that minimize flood damages during
the base flood and create no additional threats to public safety.
(6) Any applicant to whom a variance is granted shall be given
written notice that the structure will be permitted to be built with a
lowest floor elevation below the regulatory flood elevation and that the
cost of flood insurance will be commensurate with the increased risk
resulting from the reduced lowest floor elevation. A copy of the notice
shall be recorded by the Floodplain Administrator in the office of the
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Ordinance 90- 118
Contra Costa County Recorder and shall be recorded in a manner so
that it appears in the chain of title of the affected parcel of
land.
(Ords. 90-111 , 88-50, 87-45. )
SECTION III. Chapter 92-8 of the County Ordinance Code is amended
by adding Section 92-8.006:
92-8 .006 . Flood Hazard Areas. All subdivisions subject to the
provisions of this title shall comply with the standards for
subdivisions set forth in Section 82-28.1006 of this Code.
(Ord. 90-118 . ).
SECTION IV. EFFECTIVE DATE This ordinance shall become effective
30 days after° passage, and within 15 days of passage, shall be
published once, with the names of the Supervisors voting for and
against it, in the Contra Costa Times, a newspaper of general
circulation published in this county.
PASSED ON December 4, 1990 by the following vote:
AYES: Supervisors Powers, Schroder, McPeak, Torlakson and Fanden
NOES: None
ABSENT: None
ABSTAIN:None
ATTEST: PHIL BATCHELOR, Clerk of
the Board of Supervisors and County
Administrator.
By: D , Deputy
Boar Chair
JH: jn
4:f lood.ord
8/7/87
10/12/87
6/1/88
11/8/90
11/19/90
11/26/90
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Ordinance 90- 118