HomeMy WebLinkAbout2023 01 11 Flood Damage Prevention_Ecology CommentsJefferson County Code
Chapter 15.15 FLOOD DAMAGE PREVENTION
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The Jefferson County Code is current through Ordinance 3-23, passed July 3, 2023.
Chapter 15.15
FLOOD DAMAGE PREVENTION
Sections:
15.15.010 Statutory authorization.
15.15.015 Severability.
15.15.016 General exemptions.
15.15.020 Findings of fact.
15.15.030 Statement of purpose.
15.15.040 Methods of reducing flood losses.
15.15.050 Definitions.
15.15.060 General provisions.
15.15.070 Administration.
15.15.080 Provisions for flood hazard reduction.
15.15.010 Statutory authorization.
The Legislature of the State of Washington has delegated the responsibility to local governmental units to adopt
regulations designed to promote the public health, safety, and general welfare of its citizenry. Therefore, Jefferson
County does ordain as follows. [Ord. 5-19 § 2 (App. A)]
15.15.015 Severability.
If any section, clause, sentence, or phrase of this chapter is held to be invalid or unconstitutional by any court of
competent jurisdiction, then said holding shall in no way affect the validity of the remaining portions of this chapter.
[Ord. 5-19 § 2 (App. A)]
15.15.016 General exemptions.
To determine if a development proposal is exempt from the requirement for a flood development permit, the project
proponent shall submit documentation supporting compliance with the applicable exemption below for review by
the development services manager, who shall retain documentation of the decision. These exemptions are limited in
scope and shall not be approved if any of the following are part of a larger development proposal. After review by
the development services manager, the following may be exempt from the requirement for a flood development
permit:
(1) Routine maintenance of existing landscaping that does not involve grading, excavation, or filling;
(2) Removal of noxious weeds, hazardous trees, and replacement of nonnative vegetation with native vegetation;
provided, weed removal is based on the Jefferson County noxious weed list and is conducted in accordance with the
noxious weed control board weed control guidance;
(3) Normal maintenance of above-ground public utilities and facilities, such as replacing power lines and utility
poles, but does not include connecting or extending lines onto private property, such as residential utility lines;
(4) Normal road maintenance, such as filling potholes, repaving, installing signs and traffic signals; provided, that
no expansion is proposed;
(5) Normal maintenance of a levee or other flood control facility, as prescribed in the operations and maintenance
plan for the facility; provided, that normal maintenance does not include repair from flood damage, any expansion of
the prism, face or toe, or the addition of material for protection or armor; and
(6) Plowing and other normal farm practices on legally existing agricultural areas; provided, that there are not new
structures, filling, or ground clearing. [Ord. 5-19 § 2 (App. A)]
15.15.020 Findings of fact.
(1) The flood hazard areas of Jefferson 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
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The Jefferson County Code is current through Ordinance 3-23, passed July 3, 2023.
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 the cumulative effect of obstructions in areas of special flood hazards which
increase flood heights and velocities, and when inadequately anchored damage uses in other areas. Uses that are
inadequately floodproofed, elevated, or otherwise protected from flood damage also contribute to the flood loss.
(3) Those development permits seeking to construct within critical areas and/or a flood hazard area shall be subject
to this chapter.
(4) Jefferson County regulates development in frequently flooded areas through critical area protection standards
found in Chapter 18.22 JCC.
(5) Regulations that govern development in flood hazard areas may be found in Chapter 18.25 JCC – Shoreline
Master Program.
(6) Regulations that govern development in flood hazard areas may be found in Chapter 15.05 JCC – Building
Codes.
(7) Regulations that govern development in flood hazard areas may be found in Chapter 18.30 JCC – Development
Standards.
(8) Regulations that govern development in flood hazard areas may be found in Chapter 8.15 JCC – On-Site Sewage
Code.
(9) Development is prohibited in floodways, unless expressly allowed under the floodway provisions of JCC
15.15.080(4). [Ord. 5-19 § 2 (App. A)]
15.15.030 Statement of purpose.
It is the purpose of this chapter to promote the public health, safety, and general welfare; reduce the annual cost of
flood insurance; and 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 and 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 sound use and development of areas of special flood
hazard so as to minimize future flood blight areas;
(7) To ensure that potential buyers are notified that property is in an area of special flood hazard;
(8) To ensure that those who occupy the areas of special flood hazard assume responsibility for their actions; and
(9) To ensure that those who occupy areas within the special flood hazard area participate in and maintain eligibility
for flood insurance and disaster relief. [Ord. 5-19 § 2 (App. A)]
15.15.040 Methods of reducing flood losses.
In order to accomplish its purposes, this chapter includes methods and provisions for:
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The Jefferson County Code is current through Ordinance 3-23, passed July 3, 2023.
(1) Restricting or prohibiting development which is dangerous to health, safety, and property due to water or erosion
hazards, or which result in damaging increases in erosion or in flood heights or velocities;
(2) Requiring that development vulnerable to floods, including facilities which serve such development, be protected
against flood damage at the time of initial construction;
(3) Controlling the alteration of natural floodplains, stream channels, and natural protective barriers, which help
accommodate or channel floodwaters;
(4) Controlling filling, grading, dredging, and other development which may increase flood damage; and
(5) Preventing or regulating the construction of flood barriers that unnaturally divert floodwaters or may increase
flood hazards in other areas. [Ord. 5-19 § 2 (App. A)]
15.15.050 Definitions.
“Alteration of watercourse” means any action that will change the location of the channel occupied by water within
the banks of any portion of a riverine water body.
“Appeal” means a request for a review of the interpretation of any provision of this chapter or a request for a
variance.
“Area of shallow flooding” means a designated AO, AH, or VO zone on the flood insurance rate map (FIRM) with a
one percent or greater annual chance of flooding to an average depth of one to three feet where a clearly defined
channel does not exist, where the path of flooding is unpredictable, and where velocity flow may be evident. Such
flooding is characterized by ponding or sheet flow. AO zones have base flood depths that range from one to three
feet above the natural ground; a clearly defined channel does not exist; the path of flooding is unpredictable and
indeterminate; and velocity flow may be evident. AO is characterized as sheet flow; AH indicates ponding, and is
shown with standard base flood elevations.
“Area of special flood hazard” means the land in the floodplain within a community subject to a one percent or
greater chance of flooding in any given year. It is shown on the flood insurance rate map (FIRM) as zone A, AO,
AH, AE, A99, or AR (V, VO, VE). “Special flood hazard area” is synonymous in meaning with the phrase “area of
special flood hazard.”
ASCE 24: THE MOST RECENTLY PUBLISHED VERSION OF ASCE 24, FLOOD RESISTANT DESIGN AND
CONSTRUCTION, PUBLISHED BY THE AMERICAN SOCIETY OF CIVIL ENGINEERS.
“Base flood” means the flood having a one percent chance of being equaled or exceeded in any given year(also
referred to as the “100-year flood”).
“Basement” means any area of the building having its floor subgrade (below ground level) on all sides.
“Breakaway wall” means a wall that is not part of the structural support of the building and is intended through its
design and construction to collapse under specific lateral loading forces without causing damage to the elevated
portion of the building or supporting foundation system.
Building: See "Structure."
Building Code: The currently effective versions of the International Building Code and the International
Residential Code adopted by the State of Washington Building Code Council.
“Coastal high hazard area” means an area of special flood hazard extending from offshore to the inland limit of a
primary frontal dune along an open coast and any other area subject to high velocity wave action from storms or
seismic sources. The area is designated on the FIRM as zone VE or V.
“Community” means unincorporated Jefferson County, Washington.
Commented [MG1]: Added definitions with an asterisk
are mandatory to be in compliance with WA model flood
ordinance. All other added definitions are optional. Changes
made to existing definitions are mandatory to be in
compliance with WA model ordinance.
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The Jefferson County Code is current through Ordinance 3-23, passed July 3, 2023.
“Critical facility” means a facility for which even a slight chance of flooding might be too great. Critical facilities
include (but are not limited to) schools, nursing homes, hospitals, police, fire and emergency response installations,
and installations which produce, use, or store hazardous materials or hazardous waste.
“Cumulative substantial damage” means flood-related damages sustained by a structure on two separate occasions
during a 10-year period for which the cost of repairs at the time of each such flood event, on the average, equals or
exceeds 25 percent of the market value of the structure before the damage occurred.
“Development” means any manmade change to improved or unimproved real estate, including, but not limited to,
buildings or other structures, mining, dredging, filling, grading, paving, excavation or drilling operations or storage
of equipment or materials.
“Elevated building” means, for insurance purposes, a nonbasement building that has its lowest elevated floor raised
above ground level by foundation walls, shear walls, posts, piers, pilings, or columns.
“Elevation certificate” means an administrative tool of the National Flood Insurance Program (NFIP) that can be
used to provide elevation information, to determine the proper insurance premium rate, and to support a request for a
letter of map amendment (LOMA) or letter of map revision based on fill (LOMR-F).
Essential Facility: This term has the same meaning as “Essential Facility” defined in ASCE 24.
Table 1-1 in ASCE 24-14 further identifies building occupancies that are essential facilities.
“Existing manufactured home park or subdivision” means a manufactured home park or subdivision for which the
construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including, at a
minimum, the installation of utilities, the construction of streets, and either final site grading or the pouring of
concrete pads) is completed before the effective date of the floodplain management regulations adopted by a
community.
“Expansion to an existing manufactured home park or subdivision” means the preparation of additional sites by the
construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including the
installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads).
Farmhouse: A single-family dwelling located on a farm site where resulting agricultural products are not produced
for the primary consumption or use by the occupants and the farm owner. “Flood” or “flooding” means:
(1) A general and temporary condition of partial or complete inundation of normally dry land areas from:
(a) The overflow of inland or tidal waters.
(b) The unusual and rapid accumulation of runoff of surface waters from any source.
(c) Mudslides (i.e., mudflows) which are proximately caused by flooding as defined in subsection (1)(b) of this
definition and are akin to a river of liquid and flowing mud on the surfaces of normally dry land areas, as when
earth is carried by a current of water and deposited along the path of the current.
(2) 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 subsection (1)(a) of this definition.
“Flood elevation study” means an examination, evaluation and determination of flood hazards and, if appropriate,
corresponding water surface elevations, or an examination, evaluation and determination of mudslide (i.e., mudflow)
and/or flood-related erosion hazards. Also known as a Flood Insurance Study (FIS).
“Flood insurance rate map (FIRM)” means an official map of a community, on which the Federal Insurance
Administration has delineated both the special hazard areas and the risk premium zones applicable to the
community. A FIRM that has been made available digitally is called a “digital flood insurance rate map (DFIRM).”
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The Jefferson County Code is current through Ordinance 3-23, passed July 3, 2023.
“Flood insurance study (FIS)” means the official report provided by the Federal Insurance Administration that
includes flood profiles, the flood boundary-floodway map, and the water surface elevation of the base flood.
“Floodplain administrator” means the community official designated by title to administer and enforce the
floodplain management regulations.
Floodplain management regulations: Zoning ordinances, subdivision regulations, building codes, health regulations,
special purpose ordinances (such as floodplain ordinance, grading ordinance and erosion control ordinance) and
other application 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.
“Floodproofing” means any combination of structural and nonstructural additions, changes, or adjustments to
structures which reduce or eliminate risk of flood damage to real estate or improved real property, water and sanitary
facilities, structures, and their contents. Flood proofed structures are those that have the structural integrity and
design to be impervious to floodwater below the Base Flood Elevation. Floodproofing, as defined here, is limited to
the nonresidential development provisions of JCC 15.15.080(2)(b); floodproofing is not applicable to residential
development.
“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 a designated
height. Also referred to as "Regulatory Floodway."
“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, and does not include long-
term storage or related manufacturing facilities.
“Highest adjacent grade” means the highest natural elevation of the ground surface prior to construction next to the
proposed walls of a structure.
“Historic structure” means any structure that is:
(1) Listed individually in the National Register of Historic Places (a listing maintained by the Department of the
Interior) or preliminarily determined by the Secretary of the Interior as meeting the requirements for individual
listing on the National Register;
(2) Certified or preliminarily determined by the Secretary of the Interior as contributing to the historical significance
of a registered historic district or a district preliminarily determined by the Secretary to qualify as a registered
historic district;
(3) Individually listed on a state inventory of historic places in states with historic preservation programs which have
been approved by the Secretary of the Interior; or
(4) Individually listed on a local inventory of historic places in communities with historic preservation programs that
have been certified either:
(a) By an approved state program as determined by the Secretary of the Interior; or
(b) Directly by the Secretary of the Interior in states without approved programs.
“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 nonelevation design requirements of this chapter found at JCC 15.15.080(2)
(i.e., provided there are adequate flood openings).
“Manufactured home” means a structure, transportable in one or more sections, which is built on a permanent
chassis and is designed for use with or without a permanent foundation when attached to the required utilities. This
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term includes park model manufactured homes. The term “manufactured home” does not include a
“recreational vehicle.”
“Manufactured home park or subdivision” means a parcel (or contiguous parcels) of land divided into two or more
manufactured home lots for rent or sale.
*Mean Sea Level: For purposes of the National Flood Insurance Program, the vertical datum to
which Base Flood Elevations shown on a community's Flood Insurance Rate Map are referenced.
“New construction” means, for the purposes of determining insurance rates, structures for which the start of
construction commenced on or after the effective date of an initial FIRM or after December 31, 1974, whichever is
later, and includes any subsequent improvements to such structures. For floodplain management purposes, “new
construction” means structures for which the start of construction commenced on or after the effective date of a
floodplain management regulation adopted by a community and includes any subsequent improvements to such
structures.
“New manufactured home park or subdivision” means a manufactured home park or subdivision for which the
construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including, at a
minimum, the installation of utilities, the construction of streets, and either final site grading or the pouring of
concrete pads) is completed on or after the effective date of adopted floodplain management regulations adopted by
a community.
One hundred year flood or 100 year flood: See "Base flood."
“Reasonably safe from flooding” means development that is designed and built to be safe from flooding based on
consideration of current flood elevation studies, historical data, high water marks and other reliable data known to
the community. In unnumbered A zones where no flood elevation is available, “reasonably safe from flooding”
means that the lowest floor is at least two feet above the highest adjacent grade.
“Recreational vehicle” means a vehicle:
(1) Built on a single chassis;
(2) Four hundred square feet or less when measured at the largest horizontal projection;
(3) Designed to be self-propelled or permanently towable by a light duty truck; and
(4) Designed primarily not for use as a permanent dwelling but as temporary living quarters for recreational,
camping, travel, or seasonal use.
This term includes park model manufactured homes.
“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 foundation. Permanent construction
does not include land preparation, such as clearing, grading and filling; nor does it include the installation of streets
and/or walkways; nor does it include excavation for a basement, footings, piers, or foundations or the erection of
temporary forms; nor does it include the installation on the property of accessory buildings, such as garages or sheds
not occupied as dwelling units or not part of the main structure. For a substantial improvement, the “actual start of
construction” means the first alteration of any wall, ceiling, floor, or other structural part of a building, whether or
not that alteration affects the external dimensions of the building.
Commented [MG2]: Added in language for park model
manufactured homes.
Commented [MG3]: Added in language for park model
manufactured homes.
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“Structure” means, for floodplain management purposes, a walled and roofed building, including a gas or liquid
storage tank that is principally above ground, as well as a manufactured home. “Structure,” for insurance purposes,
means:
(1) A building, with two or more outside rigid walls and a fully secured roof, that is affixed to a permanent site;
(2) A manufactured home (a manufactured home, also known as a mobile home, is a structure built on a permanent
chassis, transported to its site in one or more sections, and affixed to a permanent foundation); or
(3) A travel trailer without wheels, built on a chassis and affixed to a permanent foundation, that is regulated under
the community’s floodplain management and building ordinances or laws.
For the latter purpose, “structure” does not mean a recreational vehicle or a park trailer or other similar vehicle,
except as described in subsection (3) of this definition, or a gas or liquid storage tank.
“Substantial damage” means damage of any origin sustained by a structure whereby the cost of restoring the
structure to its before-damaged condition would equal or exceed 50 percent of the market value of the structure
before the damage occurred.
“Substantial improvement” means any repair, reconstruction, rehabilitation, addition, or other improvement of a
structure, the cost of which equals or exceeds 50 percent of the market value of the structure before the start of
construction of the improvement. This term includes structures which have incurred substantial damage, regardless
of the actual repair work performed. The term does not, however, include either:
(1) Any project for improvement of a structure to correct pre-cited existing violations of state or local health,
sanitary, or safety code specifications which have been previously identified by the local code enforcement official
and which are the minimum necessary to assure safe living conditions; or
(2) Any alteration of a historic structure; provided, that the alteration will not preclude the structure’s continued
designation as a historic structure.
“Variance” means a grant of relief by a community from the terms of a floodplain management regulation.
“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 44 CFR 60.3(b)(5), (c)(4), (c)(10), (d)(3), (e)(2), (e)(4), or
(e)(5) is presumed to be in violation until such time as that documentation is provided.
“Water dependent” means a structure for commerce or industry that cannot exist in any other location and is
dependent on the water by reason of the intrinsic nature of its operations. [Ord. 5-19 § 2 (App. A)]
15.15.060 General provisions.
(1) Lands to Which This Chapter Applies. This chapter shall apply to all areas of special flood hazards within the
jurisdiction of Jefferson County.
(2) Basis for Establishing the Areas of Special Flood Hazard. The areas of special flood hazard identified by the
Federal Insurance Administration in a scientific and engineering report entitled “The Flood Insurance Study for
Jefferson County, Washington, and Incorporated Areas” dated June 7, 2019, and any revisions thereto, with an
accompanying flood insurance rate map (FIRM), and any revisions thereto, are hereby adopted by reference and
declared to be a part of this chapter. The flood insurance study and the FIRM are on file at Jefferson County
department of community development (621 Sheridan Street, Port Townsend, Washington 98368). The best
available information for flood hazard area identification as outlined in JCC 15.15.070(3)(b) shall be the basis for
regulation until a new FIRM is issued that incorporates data utilized under JCC 15.15.070(3)(b).
(3) Changes to Special Flood Hazard Area. If a project will alter the BFE or boundaries of the SFHA, then the
project proponent shall provide the community with engineering documentation and analysis regarding the proposed
change. If the change to the BFE or boundaries of the SFHA would normally require a letter of map change, then the
project proponent shall initiate, and receive approval of, a conditional letter of map revision (CLOMR) prior to
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approval of the development permit. The project shall be constructed in a manner consistent with the approved
CLOMR.
(4) Requirement to Submit New Technical Data. Within six months, notify FEMA of changes in the base flood
elevation by submitting technical or scientific data, so that insurance rates and floodplain management requirements
will be based on current data not currently found in this chapter, as required by 44 CFR 65.3.
(5) Penalties for Noncompliance. No structure or land shall hereafter be constructed, located, extended, converted,
or altered without full compliance with the terms of this chapter and other applicable regulations. Violations of the
provisions of this chapter by failure to comply with any of its requirements (including violations of conditions and
safeguards established in connection with conditions) shall constitute a misdemeanor. Any person who violates this
chapter or fails to comply with any of its requirements shall be deemed to have committed a violation. Upon
conviction thereof, the violator may be fined not more than $1,000 or imprisoned for not more than 90 days, or both,
for each violation, and in addition shall pay all costs and expenses involved in the case. Nothing herein contained
shall prevent Jefferson County from taking such other lawful action as is necessary to prevent or remedy any
violation.
(6) Abrogation and Greater Restrictions. This chapter is not intended to repeal, abrogate, or impair any existing
easements, covenants, or deed restrictions. However, where this chapter and another ordinance, easement, covenant,
or deed restriction conflict or overlap, whichever imposes the more stringent restrictions shall prevail.
(7) Interpretation. In the interpretation and application of this chapter, all provisions shall be:
(a) Considered as minimum requirements;
(b) Liberally construed in favor of the governing body; and
(c) Deemed neither to limit nor repeal any other powers granted under state statutes.
(8) Warning and Disclaimer of Liability. The degree of flood protection required by this chapter is considered
reasonable for regulatory purposes and is based on scientific and engineering considerations. Larger floods can and
will occur on rare occasions. Flood heights may be increased by manmade or natural causes. This chapter does not
imply that land outside the areas of special flood hazards or uses permitted within such areas will be free from
flooding or flood damages. This chapter shall not create liability on the part of Jefferson County, any officer or
employee thereof, or the Federal Insurance Administration for any flood damages that result from reliance on this
chapter or any administrative decision lawfully made hereunder. [Ord. 5-19 § 2 (App. A)]
15.15.070 Administration.
(1) Establishment of Development Permit.
(a) Development Permit Required. A development permit shall be obtained before construction or development
begins within any area of special flood hazard established in JCC 15.15.060(2). The permit shall be for all
structures including manufactured homes, as set forth in the “Definitions” (JCC 15.15.050), and for all
development including fill and other activities, also as set forth in the “Definitions” (JCC 15.15.050).
(b) Application for Development Permit. Application for a development permit shall be made on forms
furnished by the development review division of the department of community development for Jefferson
County and may include, but not be limited to, plans in duplicate drawn to scale showing the nature, location,
dimensions, and elevations 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:
(i) Elevation in relation to mean sea level of the lowest floor (including basement) of all structures
recorded on a current elevation certificate with Section B completed by the local official;
(ii) Elevation in relation to mean sea level to which any structure has been floodproofed;
(iii) Certification by a registered professional engineer or architect that the floodproofing methods for any
nonresidential structure meet floodproofing criteria in JCC 15.15.080(2)(b); and
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(iv) Description of the extent to which a watercourse will be altered or relocated as a result of proposed
development.
(v) Where a structure is proposed in a V, V1-30, or VE zone, a V-zone design certificate;
(vi) Where development is proposed in a floodway, an engineering analysis indication no rise of the Base
Flood Elevation, and
(vii) Any other such information that may be reasonably required by the Floodplain Administrator in order
to review the application.
(2) Designation of the Local Administrator. The Jefferson County Community Development Director development
services manager is hereby appointed to administer and implement this chapter by granting or denying development
permit applications in accordance with its provisions. The Community Development Director may appoint a
designee to implement the standards of this chapter.
(3) Duties and Responsibilities of the Local Administrator. Duties of the development services managerCommunity
Development Director or their designee shall include, but not be limited to:
(a) Permit Review.
(i) Review all development permits to determine that the permit requirements of this chapter have been
satisfied.
(ii) Review all development permits to determine that all necessary permits have been obtained from those
federal, state, or local governmental agencies from which prior approval is required.
(iii) Review all development permits to determine if the proposed development is located in the floodway.
If located in the floodway, assure that the encroachment provisions of JCC 15.15.080(4)(a) are met.
(iv) The site is reasonably safe from flooding;
(v) Notify FEMA when annexations occur in the Special Flood Hazard Area.
(b) Use of Other Base Flood Data (in A and V zones). When base flood elevation data has not been provided
(in A or V zones) in accordance with JCC 15.15.060(2), Basis for Establishing the Areas of Special Flood
Hazard, the development service manager shall obtain, review, and reasonably utilize any base flood elevation
and floodway data available from a federal, state or other source, in order to administer JCC 15.15.080(2),
Specific Standards, and 15.15.080(4), Floodways.
(c) Information to Be Obtained and Maintained.
(i) Where base flood elevation data is provided through the flood insurance study, FIRM, or required as in
subsection (3)(b) of this section, obtain and record the actual (as-built) elevation (in relation to mean sea
level) of the lowest floor (including basement) of all new or substantially improved structures, and
whether or not the structure contains a basement. Recorded on a current elevation certificate with Section
B completed by the local official.
(ii) For all new or substantially improved floodproofed nonresidential structures where base flood
elevation data is provided through the FIS, FIRM, or as required in subsection (3)(b) of this section:
(A) Obtain and record the elevation (in relation to mean sea level) to which the structure was
floodproofed.
(B) Maintain the floodproofing certifications required in subsection (1)(b)(iii) of this section.
Commented [MG4]: Please make sure this language
reflects the correct staff member.
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(iii) Maintain for public inspection all records pertaining to the provisions of this chapter.
(iv) Obtain and maintain documentation of the elevation of the bottom of the lowest horizontal structural
member in V or VE zones.
(v) Certification required by JCC 15.15.080(4).
(vi) Records of all variance actions, including justification for their issuance.
(vii) Improvement and damage calculations.
(d) Alteration of Watercourses.
(i) Notify adjacent communities and the Department of Ecology prior to any alteration or relocation of a
watercourse, and submit evidence of such notification to the Federal Insurance Administration.
(ii) Require that maintenance is provided within the altered or relocated portion of said watercourse so that
the flood-carrying capacity is not diminished.
(e) Interpretation of FIRM Boundaries. Make interpretations where needed as to exact location of the
boundaries of the areas of special flood hazards (e.g., 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. Such appeals shall be granted consistent with the standards
of Section 60.6 of the Rules and Regulations of the National Flood Insurance Program.
(4) Conditions for Variances.
(a) Generally, the only condition under which a variance from the elevation standard may be issued is for new
construction and substantial improvements to be erected on a small or irregularly shaped lot contiguous to and
surrounded by lots with existing structures constructed below the base flood level. As the lot size increases, the
technical justification required for issuing the variance increases.
(b) Variances shall not be issued within a designated floodway if any increase in flood levels during the base
flood discharge would result.
(c) Variances shall only be issued upon a determination that the variance is the minimum necessary,
considering the flood hazard, to afford relief.
(d) Variances shall only be issued upon:
(i) A showing of good and sufficient cause;
(ii) A determination that failure to grant the variance would result in exceptional hardship to the applicant;
(iii) A determination that the granting of a variance will not result in increased flood heights, additional
threats to public safety, extraordinary public expense, create nuisances, cause fraud on or victimization of
the public, or conflict with existing local laws or ordinances.
(e) Variances as interpreted in the National Flood Insurance Program are based on the general zoning law
principle that they pertain to a physical piece of property; they are not personal in nature and do not pertain to
the structure, its inhabitants, economic or financial circumstances. They primarily address small lots in densely
populated residential neighborhoods. As such, variances from flood elevations should be quite rare.
(f) Variances may be issued for nonresidential buildings in very limited circumstances to allow a lesser degree
of floodproofing than watertight or dry-floodproofing, where it can be determined that such action will have
low damage potential, complies with all other variance criteria except subsection (4)(b) of this section, and
otherwise complies with JCC 15.15.080(1)(a), (1)(c), and (1)(d).
Jefferson County Code
Chapter 15.15 FLOOD DAMAGE PREVENTION
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The Jefferson County Code is current through Ordinance 3-23, passed July 3, 2023.
(g) Any applicant to whom a variance is granted shall be given written notice that the permitted structure will
be built with its lowest floor below the base flood elevation and that the cost of flood insurance will be
commensurate with the increased risk.
(h) In considering variance applications, the floodplain administrator shall consider all technical evaluations, all
relevant factors, all standards specified in other sections of this chapter, and:
(i) The danger that materials may be swept onto other lands to the injury of others;
(ii) The danger to life and property due to flooding or erosion damage;
(iii) The susceptibility of the proposed facility and its contents to flood damage and the effect of such
damage on the individual owner;
(iv) The importance of the services provided by the proposed facility to the community;
(v) The necessity to the facility of a waterfront location, where applicable;
(vi) The availability of alternative locations for the proposed use which are not subject to flooding or
erosion damage;
(vii) The compatibility of the proposed use with existing and anticipated development;
(viii) The relationship of the proposed use to the comprehensive plan and floodplain management program
for that area;
(ix) The safety of access to the property in time of flood for ordinary and emergency vehicles;
(x) The expected height, velocity, duration, rate of rise, and sediment transport of the floodwaters expected
at the site; and
(xi) 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, water system, and
streets and bridges. [Ord. 5-19 § 2 (App. A)]
15.15.080 Provisions for flood hazard reduction.
(1) General Standards. In all areas of special flood hazards, the following standards are required:
(a) Anchoring.
(i) All new construction and substantial improvements, including those related to manufactured homes,
shall be anchored to prevent flotation, collapse, or lateral movement of the structure resulting from
hydrodynamic and hydrostatic loads, including the effects of buoyancy.
(ii) All manufactured homes (including park model manufactured homes) shall be anchored to prevent
flotation, collapse, or lateral movement, and shall be installed using methods and practices that minimize
flood damage. Anchoring methods may include, but are not limited to, use of over-the-top or frame ties to
ground anchors.
(b) Construction Materials and Methods.
(i) All new construction and substantial improvements shall be constructed with materials and utility
equipment resistant to flood damage.
(ii) All new construction and substantial improvements shall be constructed using methods and practices
that minimize flood damage.
Commented [MG5]: Added in park model manufactured
homes.
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Chapter 15.15 FLOOD DAMAGE PREVENTION
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The Jefferson County Code is current through Ordinance 3-23, passed July 3, 2023.
(iii) Electrical, heating, ventilation, plumbing, and air-conditioning equipment and other service facilities
shall be designed, elevated and located at least 1 foot above the base food elevation, and/or otherwise
elevated or located so as to prevent water from entering or accumulating within the components during
conditions of flooding. Locating such equipment below the base flood elevation may cause annual flood
insurance premiums to be increased.
5.1-3 Storage of Materials and Equipment
1) The storage or processing of materials that could be injurious to human, animal,
or plant life if released due to damage from flooding is prohibited in special flood
hazard areas.
2) Storage of other material or equipment may be allowed if not subject to damage
by floods and if firmly anchored to prevent flotation, or if readily removable from
the area within the time available after flood warning.
(c) Utilities.
(i) All new and replacement water supply systems shall be designed to minimize or eliminate infiltration
of floodwaters into the systems;
(ii) Water wells shall be located on high ground that is not in the floodway;
(iii) New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration
of floodwaters into the systems and discharges from the systems into floodwaters;
(iv) On-site waste disposal systems shall be located to avoid impairment to them or contamination from
them during flooding.
(d) Subdivision Proposals and Other Development Where 50 or More Lots Are Being Created or the Project
Includes Five or More Acres.
(i) All subdivision proposals shall be consistent with the need to minimize flood damage;
(ii) All subdivision proposals shall have public utilities and facilities, such as sewer, gas, electrical, and
water systems, located and constructed to minimize or eliminate flood damage;
(iii) All subdivision proposals shall have adequate drainage provided to reduce exposure to flood damage;
(iv) Where base flood elevation data has not been provided or is not available from another authoritative
source, it shall be generated for subdivision proposals and other proposed developments which contain at
least 50 lots or five acres (whichever is less).
(e) Review of Building Permits. Where elevation data is not available either through the flood insurance study,
FIRM, or from another authoritative source (JCC 15.15.070(3)(b)), applications for building permits shall be
reviewed to assure that proposed construction will be reasonably safe from flooding. The test of reasonableness
is a local judgment and includes use of historical data, high water marks, photographs of past flooding, etc.,
where available. Failure to elevate at least two feet above the highest adjacent grade in these zones may result
in higher insurance rates.
Commented [MG6]: Added in CRS class 8 elevation
language.
Commented [MG7]: "Storage of Materials and
Equipment" is an optional section.
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Chapter 15.15 FLOOD DAMAGE PREVENTION
Page 13/20
The Jefferson County Code is current through Ordinance 3-23, passed July 3, 2023.
(2) Specific Standards. In all areas of special flood hazards where base flood elevation data has been provided as set
forth in JCC 15.15.060(2), Basis for Establishing the Areas of Special Flood Hazard, or JCC 15.15.070(3)(b), Use of
Other Base Flood Data. The following provisions are required:
(a) Residential Construction.
1) In AE and A1-30 zones or other A zoned areas where the BFE has been determined or can be
reasonably obtained, new construction and substantial improvement of any residential structure shall have
the lowest floor, including basement, and all machinery, utilities and mechanical equipment elevated one
foot or more above the BFE.
2) New construction and substantial improvement of any residential structure in an AO zone shall
meet the requirements in 15.15.080(5). Mechanical equipment and utilities in an AO zone shall
be elevated at least one feet above the depth number identified and designed so as to
prevent water from entering or accumulating within the components during flooding.
3) New construction and substantial improvement of any residential structure in an Unnumbered A
zone for which a BFE is not available and cannot be reasonably obtained shall be reasonably safe from
flooding, but in all cases the lowest floor shall be at least two feet above the Highest Adjacent Grade.
4) New construction and substantial improvement of any residential structure in a V zone shall meet
the requirements in 15.15.080(6).
5) Fully enclosed areas below the lowest floor that are subject to flooding are prohibited, or shall be
designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and
exit of floodwaters. Designs must meet or exceed the following minimum criteria:
a) 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.
b) The bottom of all openings shall be no higher than one foot above grade.
c) Openings may be equipped with screens, louvers, valves, or other coverings or devices provided
that they permit the automatic entry and exit of floodwater.
d) A garage attached to a residential structure, constructed with the garage floor slab below the BFE,
must be designed to allow for the automatic entry and exit of flood waters.
Commented [MG8]: Added in CRS class 8 elevation
language.
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The Jefferson County Code is current through Ordinance 3-23, passed July 3, 2023.
Alternatively, a registered engineer or architect may design and certify engineered openings. (i) New
construction and substantial improvement of any residential structure shall have the lowest floor, including
basement, elevated one foot or more above the base flood elevation (BFE).
(ii) Fully enclosed areas below the lowest floor that are subject to flooding are prohibited, or 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 must meet or exceed the following minimum criteria:
(A) 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 shall be provided;
(B) The bottom of all openings shall be no higher than one foot above grade; and
(C) Openings may be equipped with screens, louvers, or other coverings or devices; provided, that they
permit the automatic entry and exit of floodwaters.
(b) Nonresidential Construction.
New construction and substantial improvement of any commercial, industrial or other nonresidential structure
shall meet the requirements of subsection 1 or 2, below.
1) New construction and substantial improvement of any commercial, industrial or other nonresidential
structure shall meet all of the following requirements:
a) In AE and A1-30 zones or other A zoned areas where the BFE has been determined or can be reasonably
obtained:
New construction and substantial improvement of any commercial, industrial, or other nonresidential
structure shall have the lowest floor, including basement, elevated one foot or more above the BFE, or elevated
as required by ASCE 24, whichever is greater. Mechanical equipment and utilities shall be waterproofed or
elevated least one foot above the BFE, or as required by ASCE 24, whichever is greater.
b) If located in an AO zone, the structure shall meet the requirements in Appendix A.
c) If located in an Unnumbered A zone for which a BFE is not available and cannot be reasonably obtained,
the structure shall be reasonably safe from flooding, but in all cases the lowest floor shall be at least two feet
above the Highest Adjacent Grade.
d) If located in a V, V1-30, or VE zone, the structure shall meet the requirements in Appendix B.
e) Fully enclosed areas below the lowest floor that are subject to flooding are prohibited, or shall be designed
to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of
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Chapter 15.15 FLOOD DAMAGE PREVENTION
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The Jefferson County Code is current through Ordinance 3-23, passed July 3, 2023.
floodwaters. Designs for meeting this requirement must either be certified by a registered professional engineer
or architect or must 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.
ii) The bottom of all openings shall be no higher than one foot above grade.
iii) Openings may be equipped with screens, louvers, valves, or other coverings or devices provided that they
permit the automatic entry and exit of floodwater.
iv) A garage attached to a residential structure, constructed with the garage floor slab below the BFE, must be
designed to allow for the automatic entry and exit of flood waters.
Alternatively, a registered engineer or architect may design and certify engineered openings.
2) If the requirements of subsection 1 are not met, then new construction and substantial improvement of any
commercial, industrial or other nonresidential structure shall meet all of the following requirements:
a) Be dry floodproofed so that below one foot or more above the base flood level the structure is watertight
with walls substantially impermeable to the passage of water or dry floodproofed to the elevation required by
ASCE 24, whichever is greater;
b) Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of
buoyancy;
c) Be certified by a registered professional engineer or architect that the design and methods of construction
are in accordance with accepted standards of practice for meeting provisions of this subsection based on their
development and/or review of the structural design, specifications and plans. Such certifications shall be
provided to the official as set forth in Section 4.3-3(2);
d) Nonresidential structures that are elevated, not floodproofed, must meet the same standards for space below
the lowest floor as described in 5.2-1(5); New construction and substantial improvement of any commercial,
industrial or other nonresidential structure shall either have the lowest floor, including basement, elevated one
foot or more above the base flood elevation; or, together with attendant utility and sanitary facilities, shall:
(i) Be floodproofed so that below one foot or more above 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;
(iii) Be certified by a registered professional engineer or architect that the design and methods of construction
are in accordance with accepted standards of practice for meeting provisions of this subsection based on their
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The Jefferson County Code is current through Ordinance 3-23, passed July 3, 2023.
development and/or review of the structural design, specifications and plans. Such certifications shall be
provided to the official as set forth in JCC 15.15.070(3)(c)(ii); and
(iv) Nonresidential structures that are elevated, not floodproofed, must meet the same standards for space below
the lowest floor as described in subsection (2)(a)(ii) of this section.
(c) Manufactured Homes. All manufactured homes in the floodplain to be placed or substantially improved on
sites within the special flood hazard area shall be elevated on a permanent foundation such that the lowest floor
of the manufactured home and all machinery, utilties and equipmente is elevated one foot or more above the
base flood elevation and be securely anchored to an adequately anchored foundation system to resist flotation,
collapse and lateral movement when:
(i) Outside a manufactured home park or subdivision;
(ii) In a new manufactured home park or subdivision;
(iii) An expansion to an existing manufactured home park or subdivision;
(iv) On a site in an existing park where a manufactured home has incurred substantial damage as a result
of a flood.
(d) Recreational Vehicles. Recreational vehicles (including park models) placed on sites within the special
flood hazard area are required to either:
(i) Be on the site for fewer than 180 consecutive days; or
(ii) Be fully licensed and ready for highway use, on wheels or jacking system, attached to the site only by
quick disconnect type utilities and security devices, and have no permanently attached additions; or
(iii) Meet the requirements of subsection (2)(c) of this section and the elevation and anchoring
requirements for manufactured homes.
5.2-5 Enclosed Area Below the Lowest Floor
If buildings or manufactured homes are constructed or substantially improved with fully enclosed
areas below the lowest floor, the areas shall be used solely for parking of vehicles, building
access, or storage.
(3) AE and A1-30 Zones with Base Flood Elevations But No Floodways. In areas with base flood elevations (but a
regulatory floodway has not been designated), no new construction, substantial improvements, or other development
(including fill) shall be permitted within zones A1-30 and AE on the community’s FIRM, unless it is demonstrated
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 within
the community.
(4) Floodways. Located within areas of special flood hazard established in JCC 15.15.060 are areas designated as
floodways. Since the floodway is an extremely hazardous area due to the velocity of floodwaters that can carry
debris, and increase erosion potential, the following provisions apply:
(a) Prohibit encroachments, including fill, new construction, substantial improvements, and other development
unless certification by a registered professional engineer is provided demonstrating through hydrologic and
hydraulic analyses performed in accordance with standard engineering practice that the proposed encroachment
would not result in any increase in flood levels during the occurrence of the base flood discharge;
Commented [MG9]: Optional clarifying clause to the
reader that "sites" are within the special flood hazard area.
Commented [MG10]: Optional clarifying clause to the
reader that "sites" are within the special flood hazard area.
Commented [MG11]: "Enclosed Area Below the Lowest
Floor" is a required section for compliance with WA model
flood ordinance.
Commented [MG12]: Please see WA Model Flood
Ordinance Section 5.4-2(1) "Replacement of Farmhouses in
Floodway." This is an optional provision, but we recommend
including to offer consistency for replacement of
farmhouses following RCW 86.16.041.
Language:
1)Replacement of Farmhouses in Floodway
Repairs, reconstruction, replacement, or improvements
to existing farmhouse structures located in designated
floodways and that are located on lands designated as
agricultural lands of long-term commercial significance
under RCW 36.70A.170 may be permitted subject to
the following:
a)The new farmhouse is a replacement for an
existing farmhouse on the same farm site;
b)There is no potential building site for a
replacement farmhouse on the same farm outside
the designated floodway;
c)Repairs, reconstruction, or improvements to a
farmhouse shall not increase the total square
footage of encroachment of the existing
farmhouse;
d)A replacement farmhouse shall not exceed the
total square footage of encroachment of the
farmhouse it is replacing;
e)A farmhouse being replaced shall be removed, in
its entirety, including foundation, from the
floodway within ninety days after occupancy of a
new farmhouse;
f)For substantial improvements and replacement
farmhouses, the elevation of the lowest floor of the
improvement and farmhouse respectively,
including basement, is a minimum of one foot
higher than the BFE;
g)New and replacement water supply systems are
designed to eliminate or minimize infiltration of
flood waters into the system;
h)New and replacement sanitary sewerage systems
are designed and located to eliminate or minimize
infiltration of flood water into the system and
discharge from the system into the flood waters;
and
i)All other utilities and connections to public
utilities are designed, constructed, and located to
eliminate or minimize flood damage.
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The Jefferson County Code is current through Ordinance 3-23, passed July 3, 2023.
(b) Construction or reconstruction of residential structures is prohibited within designated floodways, except
for (i) repairs, reconstruction, or improvements to a structure which do not increase the ground floor area; and
(ii) repairs, reconstruction or improvements to a structure, the cost of which does not exceed 50 percent of the
market value of the structure either (A) before the repair, or reconstruction is started, or (B) if the structure has
been damaged, and is being restored, before the damage occurred. 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 to structures identified as historic places, may be excluded in the 50 percent; and
(c) If subsection (4)(a) of this section is satisfied, all new construction and substantial improvements shall
comply with all applicable flood hazard reduction provisions of this section.
5.5 General Requirements for Other Development
All development, including manmade changes to improved or unimproved real estate for which
specific provisions are not specified in this ordinance or the state building codes with adopted
amendments and any {community name} amendments, shall:
1) Be located and constructed to minimize flood damage;
2) Meet the encroachment limitations of this ordinance if located in a regulatory floodway;
3) Be anchored to prevent flotation, collapse, or lateral movement resulting from hydrostatic
loads, including the effects of buoyancy, during conditions of the design flood;
4) Be constructed of flood damage-resistant materials;
5) Meet the flood opening requirements of Section 5.2-1(5), and
6) Have mechanical, plumbing, and electrical systems above the design flood
elevation or meet the requirements of ASCE 24, except that minimum electric
service required to address life safety and electric code requirements is permitted
below the design flood elevation provided it conforms to the provisions of the
electrical part of building code for wet locations.
(5) Standards for Shallow Flooding Areas (AO Zones). Shallow flooding areas appear on FIRMs as AO zones with
depth designations. The base flood depths in these zones range from one to three feet above ground where a clearly
defined channel does not exist, or where the path of flooding is unpredictable and where velocity flow may be
evident. Such flooding is usually characterized as sheet flow. In these areas, the following provisions apply:
Commented [MG13]: "General Requirements for other
development" is an optional but recommended addition.
This section is a good clarifier and "catch all" for general
floodplain development standards.
Formatted: Indent: Left: 0"
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The Jefferson County Code is current through Ordinance 3-23, passed July 3, 2023.
(a) New construction and substantial improvements of residential structures and manufactured homes within
AO zones shall have the lowest floor (including basement, utilities and mechanical equipment) elevated above
the highest adjacent grade to the structure, one foot or more above the depth number specified in feet on the
community’s FIRM (at least two feet above the highest adjacent grade to the structure if no depth number is
specified);
(b) New construction and substantial improvements of nonresidential structures within AO zones shall either:
(i) Have the lowest floor (including basement) elevated above the highest adjacent grade of the building
site, one foot or more above the depth number specified on the FIRM (at least two feet if no depth number
is specified). Recorded on a current elevation certificate with Section E completed; or
(ii) Together with attendant utility and sanitary facilities, be floodproofed to or above that level so that any
space below that level is watertight with walls substantially impermeable to the passage of water and with
structural components having the capability of resisting hydrostatic and hydrodynamic loads and effects of
buoyancy. If this method is used, compliance shall be certified by a registered professional engineer or
architect as in subsection (2)(b)(iii) of this section;
(c) Require adequate drainage paths around structures on slopes to guide floodwaters around and away from
proposed structures; and
(d) Recreational vehicles placed on sites within AO zones on the community’s FIRM are required to either:
(i) Be on the site for fewer than 180 consecutive days; or
(ii) Be fully licensed and ready for highway use, 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
(iii) Meet the requirements of subsections (5)(a) and (5)(c) of this section and the anchoring requirements
for manufactured homes (subsection (1)(a) of this section).
(6) Coastal High Hazard Areas. Located within areas of special flood hazard established in JCC 15.15.060(2) are
coastal high hazard areas, designated as zones V1-30, VE and/or V. These areas have special flood hazards
associated with high velocity waters from surges and, therefore, in addition to meeting all provisions in this chapter,
the following provisions shall also apply:
(a) All new construction and substantial improvements in zones V1-30 and VE (V if base flood elevation data
is available) on the community’s FIRM shall be elevated on pilings and columns so that:
(i) The bottom of the lowest horizontal structural member of the lowest floor (excluding the pilings or
columns) is elevated one foot or more above the base flood level or meets the elevation requirements of
ASCE 24, whichever is higher; and
(ii) The pile or column foundation and structure attached thereto is anchored to resist flotation, collapse
and lateral movement due to the effects of wind and water loads acting simultaneously on all building
components. Wind and water loading values shall each have a one percent chance of being equaled or
exceeded in any given year (100-year mean recurrence interval).
A registered professional engineer or architect shall develop or review the structural design, specifications and
plans for the construction, and shall certify that the design and methods of construction to be used are in
accordance with accepted standards of practice for meeting the provisions of subsections (6)(a)(i) and (ii) of
this section;
(b) Obtain the elevation (in relation to mean sea level) of the bottom of the lowest structural member of the
lowest floor (excluding pilings and columns) of all new and substantially improved structures in zones V1-30,
VE, and V on the community’s FIRM and whether or not such structures contain a basement. The development
service manager shall maintain a record of all such information;
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The Jefferson County Code is current through Ordinance 3-23, passed July 3, 2023.
(c) All new construction within zones V1-30, VE, and V on the community’s FIRM shall be located landward
of the reach of mean high tide;
(d) Provide that all new construction and substantial improvements within zones V1-30, VE, and V on the
community’s FIRM have the space below the lowest floor either free of obstruction or constructed with
nonsupporting breakaway walls, open wood lattice-work, or insect screening intended to collapse under wind
and water loads without causing collapse, displacement, or other structural damage to the elevated portion of
the building or supporting foundation system. For the purposes of this section, a breakaway wall shall have a
design safe loading resistance of not less than 10 and no more than 20 pounds per square foot. Use of
breakaway walls which exceed a design safe loading resistance of 20 pounds per square foot (either by design
or when so required by local or state codes) may be permitted only if a registered professional engineer or
architect certifies that the design proposed meets the following conditions:
(i) Breakaway wall collapse shall result from water load less than that which would occur during the base
flood; and
(ii) The elevated portion of the building and supporting foundation system shall not be subject to collapse,
displacement, or other structural damage due to the effects of wind and water loads acting simultaneously
on all building components (structural and nonstructural). Maximum wind and water loading values to be
used in this determination shall each have a one percent chance of being equaled or exceeded in any given
year (100-year mean recurrence interval).
If breakaway walls are utilized, such enclosed space shall be usable solely for parking of vehicles, building
access, or storage. Such space shall not be used for human habitation;
(e) Prohibit the use of fill for structural support of buildings within zones V1-30, VE, and V on the
community’s FIRM;
(f) Prohibit manmade alteration of sand dunes within zones V1-30, VE, and V on the community’s FIRM
which would increase potential flood damage;
(g) All manufactured homes to be placed or substantially improved within zones V1-30, V, and VE on the
community’s FIRM on sites:
(i) Outside of a manufactured home park or subdivision;
(ii) In a new manufactured home park or subdivision;
(iii) In an expansion to an existing manufactured home park or subdivision; or
(iv) In an existing manufactured home park or subdivision on which a manufactured home has incurred
“substantial damage” as the result of a flood;
shall meet the standards of subsections (6)(a) through (f) of this section and manufactured homes placed or
substantially improved on other sites in an existing manufactured home park or subdivision within zones V1-
30, V, and VE on the FIRM shall meet the requirements of subsection (2)(c)(ii) of this section; and
(h) Recreational vehicles placed on sites within zones V1-30, V, and VE on the community’s FIRM either:
(i) Be on the site for fewer than 180 consecutive days; or
(ii) Be fully licensed and ready for highway use, on its wheels or jacking system, attached to the site only
by quick disconnect type utilities and security devices, and have no permanently attached additions; or
(iii) Meet the requirements of JCC 15.15.070(1)(a) (Development Permit Required) and subsections (6)(a)
through (f) of this section.
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The Jefferson County Code is current through Ordinance 3-23, passed July 3, 2023.
(7) Critical Facility. Construction of new critical facilities shall be, to the extent possible, located outside the limits
of the special flood hazard area (SFHA) (100-year floodplain). Construction of new critical facilities shall be
permissible within the SFHA if no feasible alternative site is available. Critical facilities constructed within the
SFHA shall have the lowest floor elevated three feet above BFE or to the height of the 500-year flood, whichever is
higher. Access to and from the critical facility should also be protected to the height utilized above. Floodproofing
and sealing measures must be taken to ensure that toxic substances will not be displaced by or released into
floodwaters. Access routes elevated to or above the level of the base flood elevation shall be provided to all critical
facilities to the extent possible.
(8) Appurtenant Structures (Detached Garages and Storage Structures). In A zones (A, AE, A1-30, AH, AO),
appurtenant structures used solely for parking of vehicles, storage, or access may be constructed such that the floor
is below the BFE, provided the structure is designed and constructed in accordance with the following requirements:
(a) Use of the appurtenant structure must be limited to parking of vehicles or storage;
(b) The portions of the appurtenant structure located below the BFE must be built using flood-resistant
materials;
(c) The appurtenant structure must be adequately anchored to prevent flotation, collapse, and lateral movement;
(d) Any machinery or equipment servicing the appurtenant structure must be elevated or floodproofed to or
above the BFE;
(e) The appurtenant structure must comply with floodway encroachment provisions in subsection (4)(a) of this
section; and
(f) The appurtenant structure must be designed to allow for the automatic entry and exit of floodwaters in
accordance with subsection (2)(a)(ii) of this section.
Detached garages, storage structures, and other appurtenant structures not meeting the above standards must be
constructed in accordance with all applicable standards in subsection (1)(b) of this section.
Upon completion of the structure, certification that the requirements of this section have been satisfied shall be
provided to the floodplain administrator for verification. [Ord. 5-19 § 2 (App. A)]
5.7 Livestock Sanctuaries
Elevated areas for the for the purpose of creating a flood sanctuary for livestock are allowed on
farm units where livestock is allowed. Livestock flood sanctuaries shall be sized appropriately
for the expected number of livestock and be elevated sufficiently to protect livestock. Proposals
for livestock flood sanctuaries shall meet all procedural and substantive requirements of this
chapter.
Commented [MG14]: "Livestock Sanctuary" is a required
section for compliance with WA model flood ordinance.