HomeMy WebLinkAbout41-17 - Ord. Title 14 Building and Construction Chapter 14.22 Flood Damage PreventionORDINANCE NUMBER L/ / -/ 7
Title 14 -Building and Construction
Amendments to Chapter 14.22, Flood Damage Prevention
ORDINANCE amending Title 14, Building and Construction, Chapter 14.22, Flood Damage
Prevention.
WHEREAS, Mason County Board of County Commissioners adopted Chapter · 14.22 Flood
Damage Prevention Ordinance as part of the Mason County Code through Ordinance 87-08, on
August 18, 2008,
WHEREAS, amendments to Title 14, Chapter 14.22 of the Mason County Code fall under the
authority of RCW 36.70A060 and RCW 36.70A170 providing for the designation and regulation
of frequently flooded areas, and Chapter 86 .16 RCW providing for the administration of
National Flood Insurance Program regulation requirements by local governments;
WHEREAS, the flood hazard areas of Mason County are subject to periodic inundation which
can result 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, and
WHEREAS, these flood losses could be exacerbated 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 flood proofed,
elevated, or otherwise protected from flood damage also contribute to the flood loss.
WHEREAS, amendments to this flood damage prevention ordinance implement comprehensive
flood damage reduction measures that are necessary for public health safety and welfare and
that allow property owners to protect their property; and
WHEREAS, this Ordinance amends Chapter 14.22 to comply with federal requirements as
outlined in the federal Code of Regulations (44 CFR 60.3} and other state and federal
requirements enabling Mason County and its residents to receive flood insurance; and
WHEREAS, the Mason County Planning Advisory Commission conducted a public hearing on
Ju.~~ I~, J.()17 and recommend adoption of amendments by the Commissioners; and
NO THEREFORE, BE IT HEREBY ORDAINED that the Board of Commissioners of Mason County
hereby amends the Mason County Code Title 14 (Building and Construction), Chapter 14.22,
Flood Damage Prevention.
~h,
DATED this _\_'iL day of }W\11
ATTEST: c{J
'!4~ ~ Mel"ssa~ Clerk of the Board
APPROVED AS TO FORM:
C -. ---..........
Tim Whitehead, Chief DPA
2017 .
BOARD OF COUNTY COMMISSIONERS
~-,---.ASHINGTON
~D~I+. rex er, omm1ss1oner
mmissioner
Chapter 14.22 -FLOOD DAMAGE PREVENTION lfil
Sections:
Footnotes :
---(8) ---
Edito r's not e-Attachment B of Ord . No. 09 .14, adopted Feb. 11 , 2014 , amend ed ch . 14.22 to read as
he rein se ou t. Former ch . 14 .2 2 pertained to the sam e subject matter, consisted of§§ 14 .22 .010 -
14.2 2 .190 , and d eriv e d from Ord . 59-91 , 1991 ; Ord . 16-00 , 2000 ; Ord . 10-02 , 2002 ; Ord . 9-03 , 2003 ; Ord .
81 -07, 2007; and Ord . 87 -08 , 2008.
Article I. -Statutory, Authorization, Purpose, and Objectives
14 .22.010 -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. RCW 36.70A060 and RCW 36 .70A170 provides for the designation and regulation of frequently
flooded areas , and chapter 86.16 RCW provides for the administration of National Flood Insurance
Program regulation requirements by local governments. This chapter, as adopted and amended, shall be
known as the Mason County Flood Damage Prevention Ordinance .
(Ord . No. 09-14 , Att. B , 2-11-2014)
14.22.020 -Purpose.
(a) Background . The flood hazard areas of Mason County are subject to periodic inundation which can
result 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 . These flood losses could be exacerbated by the cumulative effect of obstructions in areas of
special flood hazards wh ich 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 .
Mason County has prepared this flood damage prevention ordinance to implement comprehensive
flood damage reduction measures that are necessary for public health safety and welfare and that allow
property owners to protect their property . Additional information about the Skokomish River valley has
been devoloped through resent studies , and suoh data is relevant to this ohapter. Further studies in the
Skokomish River floodplain are ourrently being undertaken under the authority of the Army Corps of
Engineers .
(b) Purpose . It is therefore the purpose of this chapter to promote the public health, safety, and general
welfare, and to minimize public and private losses due to flood conditions in specific areas by
provisions designed :
(1) To protect human life, health and property;
(2) To minimize expenditure of public money and costly flood damage control projects;
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(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 and farming 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 participate, along with
government, in assuming responsibility for their actions;
(9) To allow individuals to protect their life, health, and property when it is done in accordance with
all applicable laws and regulations;
(10) Implement applicable recommendations of Skokomish River Comprehensive Flood Hazard
Management Plan; and
(11) Provide for continued eligibility for National Flood Insurance Program .
14.22.030 -Methods of reducing flood losses.
In order to accomplish its purposes, this chapter provides regulatory methods and provisions for:
(a) 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 or in flood heights or
velocities;
(b) Requiring that uses vulnerable to floods, including facilities which serve such uses , be protected
against flood damage at the time of initial construction;
(c) Controlling the alteration of natural floodplains, stream channels, and natural protection barriers,
which help accommodate or channel flood waters;
(d) Controlling filling, grading, and other development which may increase flood damage;
(e) Preventing or regulating the construction of flood barriers which will unnaturally divert flood
waters or may increase flood hazards in other areas;
(f) Controlling excessive erosion by constructing sound erosion control structures and obtaining
appropriate permits and exemptions from all applicable local, state, and federal jurisdictions;
and
(g) Implementing the recommendations of adopted flood hazard studies and plans .
Article II. -Definitions
14.22.040 -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 chapter its most reasonable
application:
"A-Zone" or "zone A" means those areas shown on the flood insurance rate maps (FIRM) as that
area of land within the floodplain which would be inundated by the base flood (100-year or one percent
annualchance)flood.
Page 2
"Accessory structure" means nonresidential structures such as detached garages, sheds, garden
buildings, pole buildings, and barns which are considered normal for farming and ranching activities .
"Administrator" means the director of the Mason County Department of Community Development or
designee.
"Appeal" means the right to request for a review of the administrator's interpretation of any provision
of this chapter or a request for a variance .
"Area of shallow flooding" means a designated AO or AH zone on the flood insurance rate map
(FIRM). The base flood depths range from one to three feet; a clearly defined channel does not exist; the
path of flooding is unpredictable and indeterminate; and, velocity flow may be evident. AO is
characterized as sheet flow and AH indicates ponding .
"Area of special flood hazard" meaRS---#le land in the floodplain within a oommunity subjeot to a one
peroent or greater ohanoe of flooding on any given year. In Mason County , the designation of these areas
on FIRM maps always inoludes the letter/\. /\reas of speoial flood hazard are designated as frequently
flooded areas . means the land in the flood plain subject to a one (1) percent or greater chance of flooding
in any given year . Designation on maps always includes the letters A or V .
"Avulsion" means a sudden cutting off of land by flood, currents, or change in course of a body of
water.
"Avulsion risk areas" are the areas which have been determined to have too high a risk of avulsion to
permit new structures or expansion of existing structures .
"Base flood" means the flood having a oneJ1l percent chance of being equaled or exceeded in any
given year. Also referred to as the "100-year flood ." In Mason County , the designation on FIRM maps
alY.'ays inoludes the letter/\. Designation on maps always includes the letters A or V.
"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.
"Critical facility" means facilities 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, installations which produce, use, or store hazardous materials or hazardous
waste .
"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 V1-30, VE or V.
"Development" means any man-made change to improved or unimproved real estate, including, but
not limited to, buildings or other structures, diking, mining , dredging, filling , grading, paving, excavation or
drilling operations or storage of equipment or materials. The area contained within ring levees is
considered to be part of the development area due to its impact on flood waters .
"Development permit" see definition for "permit" under this chapter.
"Elevated building" means for insurance purposes, a nonbasement building which has its lowest
elevated floor raised above ground level by foundation walls, shear walls, post, piers, pilings, or columns.
"Elevation Certificate " means the officia l FEMA form <FEMA Form 086-0 -33) used to track
development, provide elevation information necessary to ensure compliance with community flood plain
management ordinances , and determine the proper insurance premium rate .
"Emergency" means an unanticipated and imminent threat to public health , safety, or the
environment which requires immediate action within a time period too short to allow for normal
Page 3
development permit application and review. All emergency development shall be consistent with all
Mason County Development Regulations .
"Engineering reports" are reports compiled under this chapter to address flood-related issues shall
be by an engineer licensed in the state of Washington with knowledge and experience in hydrology. The
method and rigor of all investigation, analysis and design shall be in accordance with current generally
accepted engineering standards.
"Flood" or "flooding" means a general and temporary condition of partial or complete inundation of
normally dry land areas from:
(1) The overflow of inland or tidal waters; and/or
(2) The unusual and rapid accumulation of runoff of surface waters from any source .
"Flood insurance rate map (FIRM)" means the official map on which the Federal Insurance
Administration has delineated both the areas of special flood hazards and the risk premium zones
applicable to the community .
"Flood insurance study" means the official report provided by the Federal Insurance Administration
that includes flood profiles, the flood boundary-floodway map , and the water surface elevation of the base
flood .
"Floodproofing" means any combination of structural and nonstructural additions, changes, or
adjustments to structures which reduce or eliminate flood damage to real estate or improved real
property , water and sanitary facilities, structures and their contents.
"Flood protection elevation" means one foot above the base flood elevation.
"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.
"Footprint" means the total area of the first floor of a structure , regardless of how the structure is
supported , or the total perimeter of any development other than a structure.
"Frequently flooded areas" are critical areas designated by Mason County in its Resource
Ordinance .
"Lot" means a designated parcel, tract , or area of land established by plat , subdivision or as
otherwise permitted by law, to be used , developed or built upon as a unit.
"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 chapter found at Section 14.22.160(1 )(B).
"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 . The term "manufactured home" does not include a "recreational vehicle".
"New construction" means structures for which the "start of construction" commenced on or after the
effective date of this chapter.
"Permit" means a written authorization from Mason County for any construction or development
activity on all lands regulated by this chapter. Such permits shall include, but are not limited to, excavation
and grading, permits for fills and excavations under Chapter 70 of the Uniform Building Code , shoreline
permits for developments regulated by the Mason County Shoreline Master Program, building permits for
all structures under the Uniform Building Code or Title 14, Mason County Code, or written authorization
for development under this chapter.
"Person" means any individual , partnership, corporation, association, organization , cooperative,
public or municipal corporation , or any agency of the state or local government unit however designated .
Page4
"Reasonable use exception " means the public review process undertaken to allow a proposed
development which is a reasonable use of a s ite and is consistent with the general purposes of this
chapter and the public interest.
"Recreational vehicle" means a vehicle which is:
(1) Built on a single chassis ;
(2) Four hundred square feet or less when measured at the largest horizontal projection ;
(3) Designed to be self-propelled or permanently towable by a light duty t ruck ; and
(4) Designed primarily not for use as a permanent dwelling but as temporary living quarters for
recreational , camping, travel , or seasonal use .
"Repetitive loss" means f lood -related damages sustained by a structure on two occasions during a
ten-year period for which the costs of repairs at the time of each such flood event on the average, equals
or exceeds twenty-five percent of the market value of the structure before the damage occurred .
"Special flood risk zone" means the zones A and A2 floodplain of the Skokomish River , Vance Creek
and tributaries , as identified on flood insurance rate maps 530115 0175 D and 530115 0180 D, both
dated December 8 , 1998 , or as amended.
"Start of construct ion" 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 one hundred eighty 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 excavat ion fo r a basement , footings , piers , or foundation or the erection of temporary forms ; nor
does it include the installation on the property of accessory buildings , such as ga rages or sheds not
occupied as dwelling units or not part of the main structure . For substantial improvement, the actual start
of construction means the first alteration of any wall , ce iling, floor , or other structural part of a building,
whether or not the alteration affects the external dimensions of the building .
"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 .
"Substantial damage" means damage of any origin sustained by a structure whereby cost of
restoring the structure to its before damaged condition would equal or exceed fifty percent of the market
value of the structure before the damage occurred.
"Substantial improvement" means any repair , reconstruction, or improvement of a structure , taking
place during a ten -year period, in which the cumulative cost equals or exceeds fifty 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
purpose 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.
This te rm includes structures which have incurred "repetitive loss" or "substantial damage"
regardless of the actual amount of repair work performed.
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 have been identified by the local code enforcement official ,
and which was in existence prior to the damage event or improvement , and which are solely
necessary to assure safe living conditions, or
Page 5
(2) Any alteration of a structure listed on the National Register of Historic Places or a State
Inventory of Historic Places .
"Variance" means a grant of relief from the requirements of this chapter which permits construction in
a manner that would otherwise be prohibited by this chapter.
"Wetlands" refer to the definition in the Mason County Resource Ordinance.
Table of Acronyms Used in the Ordinance Sections
FEMA: Federal Emergency Management Agency
FIRM : Flood Insurance Rate Map
NRCS : Natural Resources Conservation Service
RCW : Revised Code of Washington
WAC : Washington Administrative Code
WSDOT: Washington State Department of Transportation
(Ord . No. 09-14 , Att. B , 2-11-2014)
Article Ill. -General Provisions
14.22.050 -Lands to which this chapter applies.
This chapter shall apply to all areas of special flood hazard within the jurisdiction of Mason County .
These lands are designated as frequently flooded areas by the Mason County Resource Ordinance
pursuant to RCW 36.70A.
(Ord. No. 09-14, Att. B , 2-11-2014)
14.22.060 -Basis for establishing the areas of special flood hazard.
The areas of special flood hazard identified by the Federal Insurance Ad _ministration in a scientific
and engineering report entitled "The Flood Insurance Study for Mason County , Washington" dated May
17, 1988 , and revised December 8, 1998, with accompanying flood insurance rate maps, and any
subsequent amendments thereto3mendments which may hereafter be made by FEMA or Federal
Insurance Administration , is hereby adopted by reference and declared to be a part of this chapter. +J:le
flood insuranoe study is on file at tho Mason County Department of Community Development, Building Ill,
426 W . Cedar Street , Shelton , Washington . The best available information for flood hazard area
identification as outlined in Section 14.22 .190 shall be the basis for regulation until a new FIRM is issued
that incorporates data utilized under Section 14 .22 .190 .
(Ord. No. 09-14, Att. B, 2-11-2014)
Page 6
14.22.070 -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 . Violation 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 upon conviction thereof be fined
not more than one thousand dollars, imprisoned for not more than sixty days , or both , for each violation,
and in addition shall pay all costs and expenses involved in the case . Nothing herein contained shall
prevent Mason County from taking such other lawful action as is necessary to prevent or remedy any
violation . The Mason County Development Code Chapter 15.13 provides for enforcement of violations to
permits .
(Ord . No . 09-14 , Att . B , 2-11 -2014)
14.22.080 -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.
(Ord. No. 09-14 , Att . B , 2-11-2014)
14.22.090 -Interpretation.
In the interpretation and application of this chapter, all provisions shall be :
(1) Considered as a minimum requirements;
(2) Deemed neither to limit nor repeal any ot her powers granted under state statutes .
(Ord. No. 09-14, Att. B , 2-11-2014)
14.22 .100 -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 man-made 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 Mason County, any
officer or employee thereof, or the Federal Insurance Administration, for any flood damages that result
from reliance on this chapter or any adm inistrative decision lawfully made hereunder.
(Ord . No. 09-14 , Att. B , 2-11-201 4)
14.22.110 -Severability:
If any section , clause , sentence, or phrase of the chapter is held to be invalid or unconstitutional by
any court of competent jurisdiction , then said ho lding shall in no way affect the validity of the remaining
portions of this chapter.
(Ord . No. 09-14 , Att. B , 2-11 -2014)
Page 7
Article IV. -Administration
14.22.120 -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 Section 14 .22 .060. The
permit shall be for all structures including manufactured homes , and for all development including fill
and other activities, as set forth in the "definitions." If no other county permit is required, a
development permit shall be required .
(b) Application for Development Permit. Application for a development permit shall be made on forms
furnished by Mason County, which can be obtained from the Mason County Department of
Community Development. Application materials may include, but not be limited to, plans in triplicate
drawn to scale showing the nature, location, dimensions, and elevations of the area in question and
existing or proposed structures, fill, storage or materials, drainage facilities, and the location of the
foregoing . Specifically , the following information is required :
(1) Elevation in relation to base flood elevation , of the lowest floor (including basement) of all new
or substantially improved structures;
(2) Elevation in relation to base flood elevation to wh ich any structure has been floodproofed;
(3) Certification by a registered professional engineer or architect that the floodproofing methods for
any nonres idential structure meet the floodproofing criteria in Section 5 .2-2 (14 .22 .170(2)]; and
(4) Description of the extent to which a watercourse will be altered or relocated as a result of
proposed development.
(Ord . No . 09-14, Att. B , 2-11-2014)
14.22.130 -Designation of the administrator.
The administrator is hereby appointed to administer and implement this chapter by granting or
denying development permit applications in accordance with ordinance provisions. The administrator may
consult with other departments and/or agencies with expertise to assist in permitting decisions .
(Ord. No. 09-14 , Att . B , 2-11-2014)
14.22.140 -Duties and responsibilities of the administrator.
Duties of the administrator shall include, but not be limited to:
(1) Permit Review.
(A) Review all development permits to determine that the permit requirements of this chapter
have been satisfied.
(8) 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.
(C) Review all development permits to determine if the proposed development is located in the
floodway, or special flood risk zone as defined in Section 14.22 .040 . If located in the
Page 8
floodway, assure that the provisions of Section 14.22.190 are met. If located in a special
flood risk zone , assure that the provisions of Section 14.22.200 are met.
(D) Review applications for emergency permits . An emergency shall be defined as set forth in
WAC 173 .27 .040(2)d, which includes the following language :
"Emergency construction necessary to protect property from damage by the elements. An
"emergency" is an unanticipated and imminent threat to public health, safety, or the environment
which requires immediate action within a time too short to allow full compliance with this Ordinance.
Emergency construction does not include development of new permanent protective structures
where none previously existed . Where new protective structures are deemed by the administrator to
be an appropriate means to address the emergency situation, upon abatement of the emergency
situation , the new structure shall be removed or any permit which would have been required, absent
an emergency, pursuant to Chapter 90.58 RCW of these regulations or the local master program,
shall be obtained ."
(2) Use of Other Base Flood Data . When base flood elevation data has not been provided in
accordance with Section 14 .22 .060 , basis for establishing the areas of special flood hazard, the
administrator 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 Sections 14 .22.170 ,
Specific Standards, 14 .22.190 Floodways , and 14 .22 .200 Special Flood Risk Zone .
(3) Information to be Obtained and Maintained.
(A) Where base flood elevation data is provided through the flood insurance study or required
as in Subsection {21, obtain and record the actual (as-built) elevation (in relation to base
flood elevation) of the lowest floor, including basement, of all new or substantially improved
structures, and whether or not the structure contains a basement.
(B) For all new or substantially improved floodproofed structures :
(i) Verify and record the actual elevation (in relation to mean sea level) to which the
structure was floodproofed, and
(ii) Maintain the floodproofing certifications required in Section 14 .22 .120(b )(3).
(C) Maintain for public inspection all records pertaining to these ordinance provisions.
(4) Alteration of Watercourses .
(A) Notify adjacent communities and property owners, and the Washington State Department
of Ecology and Washington State Department of Fish and Wildlife, prior to any alteration or
relocation of a watercourse, and submit evidence of such notification to the Federal
Insurance Administration.
(B) Require that maintenance is provided within the altered or relocated portion of said
watercourse so that the flood carrying capacity is not diminished.
(5) Interpretation of FIRM Boundaries. Make interpretations where needed, as to exact location of
the boundaries of the areas of special flood hazards (for example, where there appears to be
conflict between a mapped boundary and actual field conditions). The person contesting the
location of the boundary shall be given a reasonable opportunity to appeal the interpretation as
provided by Section 14.22.150. However, if it is clear from examining the FIRM map that the
subject property or development is located within the area of special flood hazard, the person
contesting the location of the boundary shall apply to FEMA for a map amendment.
(Ord . No. 09-14 , Att. B , 2-11-2014)
14.22.150 -Variance procedure and reasonable use eJCception .
Page 9
(a) Appeal Board.
(1) The hearing examiner shall act as the board of appeals to hear and decide appeals and
requests for variances from the requirements of this chapter , as provided by Title 15, Mason
County Code.
(2) The board of appeals shall hear and decide appeals when it is alleged there is an error in any
requirement, decision , or determination made by the administrator in the enforcement or
administration of this chapter.
(3) Those aggrieved by the decision of the board of appeals, or any taxpayer, may appeal such
decision to the superior court, as provided in Chapter 36 .70 RCW.
(4) In passing upon such applications, the board of appeals shall consider all technical evaluations ,
all relevant factors , standards specified in other sections of this chapter and :
(A) The danger that materials may be swept onto other lands to the injury of others;
(B) The danger to 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 times of flood for ordinary and emergency vehicles;
(J) The expected heights, velocity, duration, rate of rise, and sediment transport of the flood
waters and the effects of wave action, if applicable, 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, water
systems, streets and bridges .
(L) The potential impacts to fish and riparian habitat, as provided for within the Fish and
Wildlife Habitat Conservation Areas chapter of the Resource Ordinance.
(5) Upon consideration of the factors of Subsection 4(a) and the purposes of this chapter, the board
of appeals may attach such conditions to the granting of variances as it deems necessary to
further the purposes of this chapter .
(6) The administrator shall maintain the records of all appeal actions and report any variances to
the Federal Insurance Administration upon request.
(b) Conditions of Variances .
(1) 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 lot of one-half acre or
less in size contiguous to and surrounded by lots with existing structures constructed below the
base flood level, providing Subsections (a)(4)(A) through (a)(4)(L) of this section have been fully
considered. As the lot size increases , the technical justification required for issuing the variance
increases .
(2) Variances may be issued for the reconstruction , rehabilitation or restoration of structures listed
on the National Register of Historic Places or the State Inventory of Historic Places, without
Page 10
regard to the procedures set forth in this section; provided, however, that the variance does not
jeopardize the listing of the structure on the National and State Register .
(3) Variances shall not be issued within a designated floodway if any increase in flood levels during
the base flood discharge would result.
(4) Variances shall only be issued upon a determination that the variance is the minimum
necessary, considering the flood hazard, to afford relief.
(5) 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 as identified in Subsection (a)(4) of this section , or
conflict with existing local laws or ordinances .
(6) 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 the flood elevations should be quite rare . Variances shall not be granted for
residential or commercial construction in floodways designated by this chapter.
(7) Variances may be issued for nonresidential buildings in very limited circumstances to allow a
lesser degree of floodproofing than watertight or dry-flood proofing, where it can be determined
that such action will have low damage potential, complies with all other variance criteria except
(b)(1 ), and otherwise complies with Sections 14 .22.160(1) and (2) of the general standards.
(8) 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 base flood elevation and that the
cost of flood insurance will be commensurate with the increased risk resulting from the reduced
lowest floor elevation .
_(o) Reasonable Use Exoeption . Nothing in this ohapter is intended to preolude all . reasonable use of
property . An applioant for a development proposal may file a request for a reasonable use exoeption
'.Vhioh shall be oonsidered by hearing examiner at a publio hearing . The reasonable use exception is
not intended to allow residential development in designated floodways .
(1) The hearing eicaminer may allow a use which is consistent with the general purposes of this
ohapter and the publio interest provided it meets the following oriteria:
(/1.) There is no other reasonable use or feasible alternative to the proposed development with
less impaot on flood levels , oritioal areas , or resource lands ; and
(B) The proposed development does not pose a threat to the publio health , safety or welfare
on or off the site ; and
(C) The inability of the applioant to derive reasonable use of the property is not the result of
aotions by the applioant in creating the undevelopable condition after the effeotive date of
the ordinanoe ; and
(D) The proposal is the minimum neoessary while still allO'lt'ing reasonable use of the site .
(2) Applioations shall inolude the following information :
(A) /1. desoription of the areas of the site whioh are oritioal areas and/or resouroe lands or
within setbaoks required under the Mason County Resource Ordinanoe ;
Page 11
(8) A description of the amount of the site which is within setbacks required by other county
standards ;
(C) A des cription of the proposed development , including a site plan and topographic contour
information adequate to determine flood depths on the site and property ;
(D) An analysis of the impact that the amount of development would have on the resource
lands or critical areas ;
(E) An analysis of 1Nhether any other reasonable use with less impact on the resource lands or
critical areas is possible;
(F) A design of the proposal so that the amount of development .proposed as reasonable use
will have the least impact practicable on the resource lands and/or critical areas;
(G) An economic analysis establishing the respective present values of development allowe4
under these regulations without the reasonable use exception and with the requested
exception or alternative exceptions ;
(H) Other information as the administrator determines is reasonably necessary to evaluate the
issue of reasonable use as it relates to the proposed development.
(3) Application process and revie 1,'I .
(A) The application shall be submitted to the administrator along with fees established by
ordinance for reasonable use exceptions .
(8) Public notice shall be as provided in Title 15 for public hearings .
(C) The administrator shall prepare an analysis of the merits of the request and make
recommendations to the board of commissioners .
(4) Except when application from this chapter 1Nould deny all reasonable use of a site , an applicant
who seeks an exception from the regulations of the ordinance shall pursue a 1Jariance as
provided in this section .
(5) The administrator shall ma in tain the records of all reasonable use exceptions granted and
report them to the Federal Insurance Administration upon request.
(Ord. No . 09-14 , Att. B, 2-11-2014)
Article V. -Provisions for Flood Hazard Reduction
14.22.160 -General standards .
In all areas of special flood hazards as shown on the flood insurance rate maps (FIRM) and as
defined in Section 14.22.040, the following standards are required :
(1) Anchoring :
A. All new construction and substantial improvements shall be anchored to prevent flotation,
collapse, or lateral movement of the structure.
B. All manufactured homes must likewise be anchored to prevent flotation, collapse, or lateral
movement , and shall be installed using methods and practices that minimize flood
Page 12
damage . Anchoring methods may include, but are not limited to, use of over-the-top or
frame ties to ground anchors . (Reference "FEMA P95 -Protecting Manufactured Homes
from Floods and Other Hazards" guidebook for additional techniques .)
(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. Electrical , heating , ventilation , plumbing , and air conditioning equipment and other service
facilities shall be designed and/or otherwise elevated or located so as to prevent water
from entering or accumulating within the components during conditions of flooding.
(3) Utilities:
A. All new and replacement water supply systems shall be designed to minimize or eliminate
infiltration of flood waters into the system.
B. The proposed water well shall be located on high ground that is not in the floodway . It shall
be protected from a one hundred-year flood and from any surface or subsurface drainage
capable of impairing the quality of the ground water supply (WAC 173-160-171 ).
C. New and replacement sanitary sewage systems shall be designed to minimize or eliminate
infiltration of flood waters into the systems and discharge from the systems into flood
waters .
D. On-site waste disposal systems shall be located to avoid impairment to them or
contamination from them during flooding .
(4) Subdivision Proposals:
A. All subdivision proposals shall be consistent with the need to minimize flood damage .
B. All subdivision proposals shall have public utilities and facilities such as sewer, gas ,
electrical , and water systems located and constructed to minimize flood damage.
C. All subdivision proposals shall have adequate drainage provided to reduce exposure to
flood damage.
D. 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 fifty lots or five acres (whichever is less).
E. Proposals for subdivisions or boundary line adjustments shall not result in any lot which is
nonconforming to the provisions of this chapter.
F. Subdivisions located entirely within a floodplain shall not be allowed increased density
through a performance or clustered subdivision as described in Title 16 . A performance
subdivision may be used for parcels located partially within a floodplain provided all
allowed building areas are located outside the floodplain , and all other regulatory
provisions are met. When feasible , lots shall be designed to locate building sites outside
the floodplain .
G . No parcel shall be created that would require a reasonable use exoeption or variance
before new residential or commercial construction would be allowed .
(5) Review of Building Permits : Where elevation data is not available either through the flood
insurance study or from another authoritative source (Section 14 .22 .140(2)), 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
Page 13
least two feet above the highest adjacent grade in these zones may result in highe r insurance
rates .
(Ord. No . 09-1 4, Att. B , 2-11-2014)
14.22.170 -Specific standards.
In all areas of special flood hazards and special flood risk zones where base flood elevation data has
been provided as set forth in Section 14.22 .060 , Basis for establishing the areas of special flood hazard
or Section 14 .22 .140(2), Use of other base flood data , the following provisions are required:
(1) Residential Construction :
A. New construction and substantial improvement of any residential structure shall have the
lowest floor , including basement, elevated one foot or more above base flood elevation.
B . 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 :
i. 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;
ii. The bottom of all openings shall be no higher than one foot above grade;
iii. Openings may be equ ipped with screens , louvers, or other coverings or devices
provided that they permit the automatic entry an exit of floodwaters .
C . If crawlspaces are used and have enclosed areas or floors below the base flood elevation,
then the following requirements apply :
i. The building must be designed and adequately anchored to resist flotation, collapse ,
and lateral movement of the structure resulting from hydrodynamic and hydrostatic
loads, including the effects of buoyancy. Hydrostatic loads and the effects of
buoyancy can usually be addressed though the required openings discussed in the
next bullet. Because of hydrodynamic loads , crawlspace construction is not
recommended in areas with flood velocities greater than five feet per second unless
the design is reviewed by a qualified design professional , such as a registered
architect or professional engineer. Other types of foundations are recommended for
these areas .
ii. The crawlspace is an enclosed area below the BFE and, as such , must have
openings that equalize hydrostatic pressures by allowing for the automatic entry and
exit of floodwaters . The bottom of each flood vent opening can be no more than one
foot above the lowest adjacent exterior grade . For guidance on flood openings, see
FEMA Technical Bulletin 1, August 2008, Openings in Foundation Walls and Walls of
Enclosures.
iii. Crawlspace construction is not permitted in V zones . Open pile or column foundations
that withstand storm surge and wave forces are required in V zones.
iv. Portions of the building below the BFE must be constructed with materials resistant to
flood damage . This includes not only the foundation walls of the crawlspace used to
elevate the building , but also any joists, insulation , or other materials that extend
below the BFE . The recommended construction practice is to elevate the bottom of
joists and all insulation above BFE . Insulation is not a flood-resistant material. When
insulation becomes saturated with floodwater, the additional weight often pulls it away
from the joists and flooring . Ductwork or other utility systems located below the
Page 14
insulation may also pull away from their supports . For more detailed guidance on
flood-resistant mate r ials see FEMA Technical Bulletin 2 , August 2008 , Flood Damage-
Resistant Materials Requirements.
v . Any building utility systems within the crawlspace must be elevated above BFE or
designed so that floodwaters cannot enter or accumulate within the system
components during flood conditions. Ductwork , in particular, must either be placed
above the BFE or sealed from floodwaters . For further guidance on the placement of
building utility systems in crawlspaces , see FEMA P-348 , Protecting Building Utilities
from Flood Damage, 1999.
vi. The interior grade of a crawlspace below the BFE must not be more than two feet
below the lowest adjacent exterior grade (LAG), shown as D in Figure 1.
vi i. The height of the below-grade crawlspace , measured from the interior grade of the
crawlspace to the top of the crawlspace foundation wall must not exceed four feet
(shown as Lin Figure 1) at any point. The height limitation is the maximum allowable
unsupported wall height according to the engineering analyses and building code
requirements for flood hazard areas (see the section Guidance for Pre-Engineered
Crawlspaces , on page 7 of FEMA Technical Bulletin 11 -01 ). This limitation will also
prevent these crawlspaces from being converted into habitable spaces .
viii. There must be an adequate drainage system that removes floodwaters from the
inte r ior area of the crawlspace . The enclosed area should be drained within a
reasonable time after a flood event. The type of drainage system will vary because of
the site gradient and other drainage characteristics, such as soil types . Possible
options include natural drainage through porous , well-drained soils and drainage
systems such as perforated pipes , drainage tiles , or gravel or crushed stone d rainage
by gravity or mechanical means .
ix . The velocity of floodwaters at the site should not exceed five feet per second for any
crawlspace . For velocities in excess of five feet per second , other foundation types
should be used.
x . Below-grade crawlspace construction in accordance with the requirements listed
above will not be considered basements .
Page 15
Floo r Jois t
Figure 1. Requirements regarding below-grade crawlspace construction
(2) Nonresidential Construction . New construction and substantial improvement of any commercial,
industrial or other nonresidential structure , except those defined as an accessory structure, shall
either have the lowest floor, including basement, elevated one foot or more above the level of
the base flood elevation; or, together with attendant utility and sanitary facilities, shall :
A. Be floodproofed so that below one foot above the base flood level, the structure is
watertight with walls substantially impermeable to the passage of water;
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 14 .22.130(3)(8);
Page 16
D. Nonresidential structures that are elevated , not floodproofed, must meet the same
standards for space below the lowest floor as described in subsection (1 )(8) of this section;
E. Applicants floodproofing nonresidential buildings shall be notified that flood insurance
premiums will be based on rates that are one foot below the floodproofed level (e.g . a
building flood proofed to one foot above the base flood level will be rated as at the base
flood level).
(3) Accessory Structures . Construction or substantial improvement of accessory structures, as
defined in Section 14 .22 .040 , shall either have the lowest floor elevated one foot or more above
the level of the base flood elevation; or must meet the following 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.
C . Openings may be equipped with screens , louvers, or other coverings provided they may
permit the automatic entry and exit of flood waters .
D. Structures shall not be designed for human habitation.
E. Structures shall be firmly anchored to prevent flotation which may result in damage to other
structures .
F. Service facilities such as electrical and heating equipment shall be elevated or
flood proofed.
(4) Critical Facility . Construction of new critical facilities shall be, to the extent possible , located
outside the limits of the base floodplain. Construction of new critical facilities shall be
permissible within the base floodplain if no feasible alternative site is available . Critical facilities
constructed within the base floodplain shall have the lowest floor elevated to three feet or more
above the level of the base flood elevation at the site . Floodproofing and sealing measures must
be taken to ensure that toxic substances will not be displaced by or released into flood waters .
Access routes elevated to or above the level of the base floodplain shall be provided to all
critical facilities to the extent possible.
(5) Manufactured Homes. All manufactured homes to be placed or substantially improved within
zones l\1 ;;JQ, Al--4 , and AE othe flood plain shall be elevated on a permanent foundation such
that the lowest floor of the manufactured home is one foot or more above the base flood
elevation ;-and tsbe securely anchored to an adequately anchored foundation system to resist
flo tation , collapse and latera l movement in accordance with the provisions of Section
14 .22.160(1 )(8). In unnumbered A zones, all manufactured homes shall be elevated such that
their lowest floor is at least two feet above· the highest adjacent elevation .
(6) Recreational Vehicles . Recreational vehicles placed on sites within zones l\1 ;;JQ , Al--4 , and AE
the flood plain -shall either:
(A) Be on site for fewer than one hundred eighty consecutive days;
(8) Be fully licensed and ready for highway use, on its wheels or jacking system, be attached
to the site only by quick disconnect type utilities and security devices , and have no
permanently attached additions.
(C) Meet the requirements of (3) and the elevation and anchoring requirements for
manufactured homes .
(Ord. No. 09-14, Att. B, 2-11-2014)
14.22.180 -AE and Al-30 zones with base flood elevations but no floodways.
Page 17
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 A 1-30 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.
(Ord. No. 09-14, Att. B, 2-11-2014)
14.22.190 -Floodways.
Located within areas of special flood hazard established in Section 14 .22 .170 are areas designated
as floodways . Since the floodway is an extremely hazardous area due to the velocity of flood waters
which carry debris, potential projectiles , and erosion potential , the following provisions apply.
(1) Encroachments are prohibited including fill, new construction, substantial improvements , and
other development unless certification by a registered professional engineer or architect is
provided demonstrating through hydrologic and hydraulic analysis performed in accordance with
standard engineering practice that the proposed encroachments shall not result in any increase
in flood levels during the occurrence of the base flood discharge.
(2) Construction or reconstruction of residential structures is prohibited within designated
floodways, except for repairs, reconstruction , or improvements to structures which do not
increase the ground floor area; and repairs, reconstruction, or improvements to a structure , the
cost of which does not exceed fifty percent of the market value of the structure either, (a) before
the repair, reconstruction, or repair is started, or (b) if the structure has been damaged , and is
being restored , before the damage occurred. Work done on structures to correct existing
violations of health, sanitary , or safety codes which have been identified by the local code
enforcement official and which are the minimum necessary to assure safe living conditions or on
structures identified as historic places shall not be included in the fifty-percent determination .
(3) If subsection (1) of this section is satisfied, all new construction and substantial improvements
shall comply with all applicable flood hazard reduction provisions of Article V , Provisions for
flood hazard reduction.
(Ord. No . 09 -14 , Att. B , 2-11-2014)
14.22.200 -Special flood risk zone-Floodplain of the Skokomish River, Vance Creek and tributaries .
(a) Special Flood Risk Zone. A special flood risk zone is hereby established for the zones A and A2
floodplain of the Skokomish River, Vance Creek and tributaries, and is illustrated on FIRM map
Community Panels #530115-0175D and #530115-01 B0D, (both December 1998). The special flood
risk zone is hereby designated as a floodway and the entire floodway is hereby designated an
avulsion risk area. Construction of a new structure or an expansion of the square foot area of an
existing structure is prohibited in this designated floodway . For purposes of this subsection, the term
structure shall not include a gas or liquid storage tank .
(b) Dikes, Levees and Other Water Flow Modification Structures.
(1) Areas where flood water releases and overflows from the main Skokomish River channel shall
not be modified , meaning levied or diked, in any manner which would result in increased stream
flow in the main channel.
(2) Maintenance to existing legally established (constructed by past permits or historically
occurring) levees, dikes, and other water flow modification structures shall be permitted with
appropriate approvals from all affected agencies, provided that the maintenance does not result
in increased stream flow within the main channel (as verified by a hydraulic engineer), and the
Page 18
maintenance is consistent with provisions and recommendations of the adopted Skokomish
River Comprehensive Flood Hazard Management Plan. Emergency alterations to dikes and
levees necessary for the protection of human life and property shall be permitted as provided for
within the applicable regulatory permit processes.
(3) If the public works director finds an imminent flood threat to the public health, safety, and
welfare exists based on :
(A) A flow capacity of seventy percent of the one hundred-year flood stage for the specific river
or creek, or
(B) A rainfall within the last forty-eight hours in excess of four inches, or
(C) Issuance of a flood warning by the National Weather Service for the specific area, or
(D) A significant isolated blockage occurs such as a log jam or slide, that impacts the
geography or water velocity such that an overflow back path has or is likely to occur ;
Then the public works director may recommend to the board of commissioners that they declare an
emergency flood condition, which shall then authorize the county to make on-site inspections on
private property of dikes and other impediments as necessary, and to direct or design immediate or
subsequent improvement, repair, removal, or modification to said dikes, levees, or other
impediments, as subject to other regulations ; and shall maintain a record of the condition and
structure of said dikes .
(4) Alterations to dikes and levees, and bank stabilization efforts that would prevent legitimate
potential emergency situations shall be permitted, provided that all affected agencies have been
notified and appropriate permits have been acquired .
(5) Activities related to the repair, maintenance or construction of bank stabilization, dikes, levees
or other related development are a permit required activity under Section 14 .22.120 of this
chapter , are subject to all provisions for development standards within this chapter, and shall
provide for appropriate inspections during and following construction and/or repair . Construction
shall meet NRCS standards, as recommended within the Skokomish River Comprehensive
Hood Hazard Management Plan, or as revised .
(6) Projects proposed by government agencies under this section as recommended within the
Skokomish River Comprehensive Flood Hazard Management Plan shall be evaluated on a
case-by-case basis . The administrator shall include the following considerations in making an
evaluation :
A. Recommendations of applicable study;
B. Provisions of this chapter;
C. Project-specific engineering;
D. Public benefit;
E. All applicable regulations.
(7) All approved permits shall require the monitoring of performance which shall include, at a
minimum, a post-construction inspection for compliance with the conditions of approval.
Additional inspections may be required when recommended by the engineering report or the
county engineer. Monitoring shall be established as a condition of approval.
(8) Dike monitoring program . Information on the condition of levees , dikes, or other structures
ascertained from successive on-site inspections shall be maintained by the county for the
purpose of updating and cataloging existing conditions as part of their ongoing flood and dike
management program . Dikes shall be monitored for safety purposes . Dikes shall be inspected
by the public works director at least biennially .
Page 19
The public works director and his designee is authorized to enter onto private or public land for
the sole purpose of inspecting dikes for flood safety and for no other purpose. The inspections shall
be done between the 8:00 a.m. and 4 :00 p.m . time period, with notice to the property owner sent by
certified mail at least fourteen days in advance, unless there is a flood emergency.
The public works director shall report on the condition of the dikes to the board of county
commissioners at the interval of once every two years. The report shall include an assessment of the
condition and structure of the dikes; an analysis of whether any improvements needs to be done ; a
statement on the ability, or lack thereof, to inspect the dikes; and any other matter of importance to
dike inspection and monitoring. The report shall also be based on the inspections and information
gathered from dike monitoring. Existing dikes monitored shall be listed or be listed by reference to
outside reports .
(c) Bridges and Roadways.
(1) Areas where flood water releases and overflows from the main Skokomish River channel shall
not be modified by construction or reconstruction of bridges or roadways , in any manner which
would result in increased stream flows or flood elevations (as verified by a hydraulic engineer).
(2) Maintenance to existing legally established ( constructed by past permits or historically
occurring) bridges and roadways shall be permitted with appropriate approvals from all affected
agencies, provided that the maintenance does not result in increased stream flows or flood
levels (as verified by a hydraulic engineer), and the maintenance is consistent with provisions
and recommendations of the adopted Skokomish River Comprehensive Flood Hazard
Management Plan . Emergency alterations to bridges and roadways necessary for the protection
of human life and property shall be permitted as provided for within the applicable regulatory
permit processes .
(3) If the public works director finds an imminent flood threat to the public health , safety , and
welfare exists based on :
(A) A flow capacity of seventy percent of the one hundred-year flood stage for the specific river
or creek, or
(B) A rainfall within the last forty-eight hours in excess of four inches, or
(C) Issuance of a flood warning by the National Weather Service for the specific area, or
(0) A significant isolated blockage occurs such as a log jam or slide, that impacts the
geography or water velocity such that an overflow bank path has or is likely to occur;
Then the public works director may recommend to the board of commissioners that they declare an
emergency flood condition, which shall then authorize the county to make on-site inspections on
private property of bridges and roadways and other impediments as necessary, and to direct or
design immediate or subsequent improvement, repair , removal, or mod ification to said impediments ,
as subject to other regulations; and shall maintain a record of such actions .
(4) Alterations to bridges and roadways that would prevent legitimate potential emergency
situations shall be permitted, provided that all affected agencies have been notified and
appropriate permits have been acquired.
(5) Activities related to the repair, maintenance or construction of bridges and roadways or other
related development are a permit required activity under Section 14.22.120 of this chapter, are
subject to all provisions for development standards within this chapter, and shall provide for
appropriate inspections during and following construction and/or repair.
(6) Projects proposed by government agencies under this section as recommended within the
Skokomish River Comprehensive Flood Hazard Management Plan shall be evaluated on a
case-by-case basis . The administrator shall include the following considerations in making an
evaluation:
(A) Recommendations of applicable study ;
Page 20
(B) Provisions of this chapter;
(C) Project-specific engineering;
(D) Public benefit;
(E) All applicable regulations.
(7) All approved permits shall require the monitoring of performance which shall include, at a
minimum, a post-construction inspection for compliance with the conditions of approval.
Additional inspections may be required when recommended by the engineering report or the
county engineer. Monitoring shall be established as a condition of approval.
Projects proposed by WSDOT under this section and receiving Federal Highway Administration
funding shall be consistent with the recommendations within the Skokomish River Comprehensive
Flood Hazard Management Plan and shall be evaluated on a case by case basis . The administrator
shall include the following considerations in making an evaluation and issuing a permit:
(A) Recommendations of project specific studies prepared by or on behalf of WSDOT;
(B) All other provisions of this ordinance do not apply;
(C) Project specific engineering shall be completed in accordance with the WSDOT Design
Manual;
(D) Provide a public benefit;
(E) Provide less than a cumulative one foot rise in the proposed one hundred-year flood fringe
as determined by a step backwater analysis or higher. The cumulative total rise will
consider projects that have been approved as well as projects that are planned to be
approved .
(F) Compliance with all applicable state and federal regulations .
(Ord. No. 09-14, Att. A, 2-11-2014)
14 .22.210 Standards for Shallow Flooding Areas (AO ZONES).
Shallow flooding areas appear on FIRMs as AO zones with depth designations . The base flood
depth s in these zones range from 1 to 3 feet above ground where a clearly defined channel
does not exist. or where the path of flood ing is unpredictable and where velocity flow may be
evident. Such flooding is usually characterized as sheet flow . In these areas, the following
provisions apply :
(2)
(1) New construction and substantial improvements of residential structures and
manufactured homes within AO zones shall have the lowest floor (including
basement) 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).
New construction and substantial improvements of nonresidential structures within AO
zones shall either :
(ii)
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); or
Together with attendant utility and sanitary facilities , be completely flood proofed
to or above that level so that any space below that level is watertight with walls
Page 21
(3)
(4)
substantially impermeable to the passage of water and with structural
components having the capability of res isting 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 14 .22 .170.
Require adequate drainage paths around structures on slopes to guide floodwaters
around and away from proposed structures .
Recreationa l vehicles placed on sites with in AO Zones on the community"s F IR M
either :
(i)
(ii)
(iii)
Be on the site for fewer than 180 consecutive days , or
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
Meet the requirements of (1) and (3) above and the anchoring requirements for
manufactured homes .
14 .22 .220 Coastal High Hazard Areas
Located within areas of special flood hazard established in 14 .22 .060 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 meet ing all
provisions in this ordinance, the fo ll owing provisions sha ll also apply:
1) All new construction and substantial improvements in Zones V1-30 and VE (V if base
flood elevation data is avai lab le) 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
pi lings or columns) is elevated one foot or more above the base flood level; 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 stru ctura l
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 (1 )(i) and (ii).
2) Obtain the elevation (in relation to mean sea level) of the bottom of the lowest
structura l member of the lowest floor (excluding pilings and columns) of all new
and substantial ly improved structures in Zones V1-30, VE. and Von the
community"s FIRM and whether or not such structures contain a basement.
3)
• Mason County Community Services shall maintain a record of all such
information .
All new construction within Zones V1-30 , VE , and Von the community "s FIRM
sha ll be located landward of the reach of mean high tide .
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4)Provide that all new construction and substant ial improvements within Zones V1-30,
VE, and Von the community's FIRM have the space below the lowest f loor either
free of obstruction or constructed with non-supporting 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)
(ii)
Breakaway wall collapse shall result from water load less than that which
would occur during the base flood ; and
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 non-structural). 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 useable solely for
parking of vehicles, building access, or storage . Such space shall not be used
for human habitation .
5) Prohibit the use of fill for structural support of buildings within Zones V1-30, VE, and V
on the community's FIRM .
6)
7)
8)
Prohibit man-made alteration of sand dunes within Zones V1 -30, VE, and Von
the community's FIRM which would increase potential flood damage .
All manufactured homes to be placed or substantially improved within Zones V1-
30, V, and VE on the community's FIRM on sites :
(i)
(ii)
(iii)
{iv)
Outside of a manufactured home park or subdivision,
In a new manufactured home park or subdivision,
In an expansion to an existing manufactured home park or
subdivision, or
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 paragraphs (1) through (6) 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 14 .22 .170 .
Recreational vehicles placed on sites within Zones V1-30, V, and VE on the
community's FIRM either :
(j)
(ii)
Be on the site for fewer than 180 consecutive days, or
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
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(iii) Meet the requirements of 14 .22 .120 (development permit Required)
and paragraphs (1) through (6) of this section .
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