HomeMy WebLinkAbout16-00 - Ord. Amending County Flood Damage Prevention Ordinance ORDINANCE NUMBER 16-00
AMENDMENTS TO THE MASON COUNTY FLOOD DAMAGE PREVENTION ORDINANCE, AND
FREQUENTLY FLOODED AREAS AND DEFINITIONS CHAPTERS OF THE MASON COUNTY
RESOURCE ORDINANCE
AN ORDINANCE amending Mason County Flood Damage Prevention Ordinance, and Frequently Flooded Areas
Chapter1 .7 . 01 . 090 and Defmiriitions Chapter 17 . 01 . 240 of the Resource Ordinance, under the authority of Chapters
36 . 70 and 36 . 70A RCW. •
WHEREAS, the Board of County Commissioners held public hearings on January 11 , 2000, February 15, 2000 and
February 24, 2000 to consider recommendations of the Planning Commission, the Mason County Planning Department
and citizens on the proposed amendments; the board provided for public comment on proposed revisions which were
under consideration,
WHEREAS, the Mason County Planning Commission formulated its recommendation after a public hearing on
November 15, 1999 ;
WHEREAS, these hearings were duly advertised public hearings;
WHEREAS, these amendments are intended to comply with the Orders of Western Washington Growth Management
Hearings Board, Case No. : 95 -2-0073 ;
WHEREAS, the Mason County Board of County Commissioners has approved findings of fact to suport its decision as
Attachment A;
NOW, THEREFORE, BE IT HEREBY ORDAINED, that the Board of County Commissioners of Mason County
hereby approves and ADOPTS the amendments to the following regulations : the Flood Damage Prevention Ordinance
as amended, as ATTACHMENT B, the Frequently Flooded Areas Chapter 17 . 01 . 090 of the Resource Ordinance as
amended, as ATTACHMENT C. and the Definitions Chapter 17 . 01 . 240 of the Resource Ordinance, as amended, as
ATTACHMENT D .
DATED this 6 � day of ' , 2000 .
Board of County Commissioners '
Mason County, Washington ATTEST
Absent 2 / 24 / 00
John A Bolender, Chair Clerk o the Board
Mary Jo (0, C ssioner APPROVED AS TO FORM:
Cynthia Olsen, Commissioner Q �2oS�cv'i � N� ktVZ)4clnw4E
Attachment A
ORDMANCENO . 16- 00
Mason County Board of County Commissioners
Flood Damage Prevention Ordinance Amendments , and
Frequently Flooded Areas and Definitions Chapter of Resource Ordinance Amendments
Findings of Fact
1 .
Under consideration is a proposal to amend Mason County' s Flood Damage Prevention Ordinance
(FDPO) , and Frequently Flooded Areas (FFA) and Definitions chapters of the Resource
Ordinance . Revisions to regulations governing development in Mason County' s frequently
flooded areas are necessary to : meet the requirements of the Western Washington Growth
Management Hearings Board order in case #95 -2-0073 ; complete the update of Skokomish
Valley floodplain . regulations following adoption of the Skokomish River Comprehensive Flood
Hazard Management Plan (CFHMP) in December of 1996 ; to incorporate additional floodplain
studies completed for the Skokomish River and tributaries frequently flooded areas by
Skillings-Connolly, for consistency with Federal Emergency Management Authority (FEMA)
regulations, and Washington State' s Model Ordinance for floodplain administration; and to
consolidate the bulk of Mason County' s frequently flooded areas regulations into a single
document .
2 .
The county performed a substantial public participation process with public workshop , hearings,
and received substantial verbal and written public and agency comment . Further information on
comment and the review process is provided within the record .
A State Environmental Policy Act Determination of Nonsignificance was issued on these
amendments on November 8 , 1999 . The comment period ended on November 22 , 1999 . The
Department of Community Development determined that the changes to the proposal improved
environmental protections, and will not cause significant adverse environmental impact .
A Planning Commission (PC) public workshop was held on November 8 , 1999 . On November
151 1999 held a public hearing, considered the testimony along with the record before it, approved
findings of fact and recommended amendments to go forward to the Board of County
Commissioners .
3 m The Board of County Conunissioners held several public hearings to consider testimony, along
with the record before it . While the January 4 , 2000 hearing did not include presentation of the
staff report due to commissioner illness, public testimony was heard on that date, and at
subsequent public hearings on January 11 2 , 000 , and February 15 , 2000 . On that date the
commissioners closed the hearing to verbal testimony, but provided that written clarification
would still be considered . In public hearing on February 24, 2, 000 the Commissioners further
considered and adopted amendments to the regulations governing frequently flooded areas .
4 . Public cornment on the proposed November 15 1999 draft focused on concerns over
regulatory restriction of property rights, the ongoing need for further study, and recornmendations
for modifications to the draft . Agency comment focused on regulatory consistency issues .
Letters/comments included those from The Agricultural Community of the Skokomish Valley
(alternate draft ordinance) dated November 2 , 1999 , letter from Moiyra Dehee and Tom
Schreiber dated November 15 , 1999 , Department of Ecology (DOE) letter dated November 12,
1999 , and Department of Community Trade and Economic Development letter dated November
111 1999 .
Following recommended' amendments adopted by the PC on November 15 , 1999 , further agency
cornment was received relating to the PC recommended addition of a transfer of development
rights provision for portions of the Skokomish River FFA. DOE and FEMA considered this
would invalidate the extensive hydraulic analysis already performed for the Skokomish River FFA
within the CFI-MJ? 1
Further public comment and testimmy was received, including testimony in hearings, and letters
from the Skokomish Tribe dated January 4, 2000, Moiyra Dehee and Tom Schreiber dated
January 3 , 2000 , Shelloy Johnson dated January 11 , 2000, Evan Tozier, dated January 11 , 2000 .
Consideration of scientific study, further analysis, requests for clarification language, and
comments received from the public and agencies was used in developing the February 24, 2000
draft . Ultimately the determination was made not to include development rights transfers due to
concerns that the original hydraulic study completed for the Skokomish River valley was based on
complex hydraulic modelling which used the initially proposed (and retained) 3 % footprint limit .
5 :
CONSOLIDATION OF FREQUENTLY FLOODED AREAS REGULATIONS
Discussion
In the administration of the previous regulations, it was determined that it was necessary to
update regulations governing development in frequently flooded areas, incorporating the findings
of best available science to date, to consolidate the bulk of regulations governing development in
frequently flooded areas of Mason County into one document, and to include certain development
provisions currently administered within temporary resolutions previously adopted by the County.
Revisions were also necessary to accommodate the provisions of studies completed to date .
It was determined that the Flood Damage Prevention Ordinance would continue to be the guiding
document regulating development in the frequently flooded areas of Mason County, with
language contained in other documents moved into the FDPO , and further revisions made
accordingly . The FFA chapter of the Resource Ordinance is retained in its consolidated form,
with definition amendments, and referenced to the FDPO .
Findings
The revised regulations address the need to provide regulatory information from a consolidated
source, and incorporate the most recent study information available for information needs and site
analysis .
6 .
USE OF BEST AVAILABLE SCIENCE , AND PROTECTION OF THE FUNCTIONS
AND VALUES OFT E S O O ISH RIVER FREQUENTLY FLOODED AREAS
iscnssion
Several earlier scientific studies and flood lain analyses have been completed for the Skokomish
River frequently flooded area, by engineering firms with expertise in this field . These include
Skokomish River Comprehensive Flood Hazard Management Plan (CFHMP) by KCM (adopted
December 30 , 1996 , final plan February 1997) , Lower South Fork and Upper Skokomish River
Hydraulic and Geomorphic Analysis by Skillings- Connolly (August 15 , 1997) , and Discussion of
Skokomish River Valley Flood and Avulsion Hazards by Skillings- Connolly ( September 15 ,
1997) .
In the administration of previous regulations it was determined that further scientific analysis was
necessary for the frequently flooded areas of the Skokomish River and tributaries . The county
retained Skillings- Connolly. The South Fork Skokomish River and Vance Creek Hydraulic and
Geomorphic Analysis by Skillings-Connolly (June 1999, revised September 29, 1999) provides
their analysis . Avulsion risk was evaluated, and ecommendations were made including the
continuation of current regulatory provisions and consider further regulations . No new footprint
zones and further stream setback provisions were incorporated within the revised FDPO , with
provisions relating to zones mapped by previous studies as well as the most recent research .
Further analysis of digital terrain topographical maps for the Skokomish River FFA also showed
that the relationship between existing grade elevations and base flood elevations was not a
constant one, resulting in certain areas with the potential for deeper floodwaters . It was
concluded that areas where site elevation was more than two feet lower than the base flood
elevation would be treated as "no -new- footprint zones . "
Regulatory provisions for stream buffers generally reflect the intended purpose of the particular
ordinance, and are not intended to exclude, undermine or abrogate the provisions of other
applicable regulatory buffers . Thus buffer provisions of Fish and Wildlife Habitat Conservation
Area (FWHCA) buffers will apply within the Frequently Flooded Areas regulations . Within
Section 5 . 4 of the FDPO, buffers of 200 feet apply to type 1 streams in the Special Flood Risk
Area; reference is also provided into buffer requirements for all other regulations . Potential
impacts to fish and riparian habitat have been included in criteria for consideration within variance
review .
Findings
The main purpose of the FDPO is to provide regulatory guidance for development in FFA' s .
Inclusion of the findings and recommendations of scientific study enhances and further clarifies
the regulations . Setback provisions for the Skokomish River and tributaries are addressed within
the FDPO and referenced to other documents . In addition regulations which specifically address
fish and wildlife habitat and riparian protections are contained within specific chapters of the
Resource ordinance . Revisions balance the need to focus the FDPO on development regulations,
while acknowledging that consideration to and application of other regulatory provisions also
apply .
7m
CONSERVATION OF PRODUCTIVE AGRICULTURAL LAND THROUGH ESI
PROVISIONS AND DISCOURAGING OF INCOMPATIBLE USES
Discussion
Provisions for the conservation of productive agricultural land are intended to protect that use
through density provisions, and discouraging of incompatible uses . In Mason County, these
provisions are to be found in several of the County' s regulatory documents . The Mason County
Comprehensive Plan (existing, and as updated through the county' s ongoing regulatory revision
process) , establishes the overall planning basis for the designation and protection of agricultural
lands . Agricultural lands are designated, and density is provided for within the Agricultural Lands
chapter of the Resource Ordinance . In addition, the FDPO contains provisions for a maximum
allowable density of 3 % within the Detailed Study Area Zone A2 of the Skokomish River and
tributaries . During the regulatory adoption process, extensive verbal and written comment was
received relating to density provisions within the FDPO .
Findings
While the primary purpose of the FDPO is related to regulation of floodplain development,
density provisions within the Skokon sh River floodplain contribute to consolidation of scale of
development . Specific regulations addressing agricultural lands density is to be found within the
Agricultural Lands chapter of the resource ordinance . Thus the combination appears to be a
proper balancing of the diverse goals of the Growth Management Act ,
8 ,
MONITORING OF DIKE CONSTRUCTION AND IMPROVEMENTSTO ENSURE
COMPLIANCE WITH REGULATONS
Discussion
Mason County already administers regulations for development which provide for processes for
project application, review, approval, and monitoring occur through inspection . These include
adopted building codes, the Resource Ordinance, and the Shoreline Master Program, each with
requirements for permit application, review, conditions (project requirements), and inspections
administered through structure construction inspections . Over and above the provisions to be
found in other regulations, specific language was added to the FDPO . In particular, Section 5 . 4. 5
provides for review and inspection of activities related to the repair, maintenance and construction
of bank stabilization, levees or other related development .
Findings
The addition of language within the FDPO adds further provisions for ongoing review and
inspection, providing a proper balancing of diverse goals, public interests, and individual rights .
9 .
INCLUSION OF PROVISIONS WHICH ADDRESS A LSIN RISK
Discussion
To date, Mason County has overseen the execution of floodplain analysis by IBC : Skokomish
River Comprehensive Flood Hazard Management Plan, and three studies completed by
Skillings- Connolly as follows : Draft Lower South Fork and Upper Skokomish River Hydraulic
and Geomorphic Analysis (August 1997) , Discussion of Skokomish River Valley Flood and
Avulsion Hazards ( September 1997), and the recently completed South Fork of the Skokomish
River and Vance Creek Hydraulic and Geomorphic analysis and Recommendations for Action
(June 199 , revised September 1999) . In evaluating the application of floodplain avulsion risk
provisions within the FDPO, the Planning Commission requested that staff provide additional
detail of the regulatory review process . This was added to the November 15 , 2000 draft within
Section 5 . 4 -2 ( 1 ) (iv) as subsection (a) and (b) , and recommended by the Planning Commission for
adoption . The addition provides clarification that both avulsion-related studies to date, combined
with site review by the county engineer, shall be used to determine if further scientific study is
required to support the development proposal . In review of proposed revisions, the Board of
County Commissioners considered extensive scientific material, and written and verbal public
testimony, and determined that studies support the inclusion of regulations which address avulsion
risk in the floodplain of the Skokomish River, Vance Creek and tributaries . Sections and language
addressing several types of No New Footprint Zones were added .
Findings
The Board finds that the proposed regulations provide that review of avulsion risk will be
conducted in execution of floodplain regulations, based on both existing and continued scientific
study .
100
REGULATORY PROVISIONS WHICH CURTAIL CONSTRUCTION IN FLOODWAYS
Discussion
Provisions for continued eligibility for the FEMA Flood Insurance program include specific
prohibitions on encroachments into the floodway. This language is included within, and applied
as part of the FDPO . Repair and/or reconstruction of damaged structures is limited to specific
provisions which are clearly addressed . In addition, and outside the actual mapped floodway,
density provisions in the Skokomish River density floodplain limit development to a 3 % footprint
with setbacks which center development on lots . These provisions further minimize development
beyond the FEMA mapped floodway.
Findings
In reviewing the scientific data, floodplain regulations, input from the public and agencies, and
material provided by the Department of Community Development, the Board of County
Comas sisoners made the decision to uphold the prohibitions and specific limitations on
encroachment in the floodway, and include further provisions addressing development scale and
location outside the floodway, within the density floodplain of theSkokomish River.
11 .
The board finds that the proposed amendments balance the goals of the Mason County
Comprehensive Plan and the goals of the Growth Management Act, and are consistent with
FEMA and Department of Ecology provisions for regulations governing development in
floodplains .
From the preceding findings, it is concluded amendments to the Mason County Flood Damage
Prevention Ordinance, and Frequently Flooded Areas and Definitions Chapters of the Resource
Ordinance, as herein proposed, should be adopted .
✓ /.x
hair, ason County Board of County Commissioners
Date
ATTACHMENT B
FLOODMASON COUNTY EVE I ORDINANCE
SECTION 190
STATUTORY A O ZATION , , PURPOSE, AND OBJECTIVES
Li 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 . 70A. 060 and RCW 36 . 70A. 170 provides for the
designation and regulation of Frequently Flooded Areas_ and RCW 86 . 16 provides for the
administration of national flood insurance program regulation requirements by local
governments . This ordinance as adopted and amended shall be known as the Mason
County Flood Damage Prevention Ordinance . ,
.
1 . 2 PURPOSE
1 . 240)Back round : 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 .
(2) These flood losses are caused 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
floodproofed, elevated, or otherwise protected from flood damage also contribute to the
flood loss .
0) C-mrrent methods of flood control, particalarty in the Skokonlish Valley , have proven
unsatisfactory to locai residents and goveminental agencies . The Skokomish River
Comprehensive Flood Hazard Management Plan. February 1997 was adopted and
contains a hydraulic study and recommendations for density based floodplain development
regulations in the Skokomish River Valley . The Draft Lower South Fork and Upper
Skokomish River Hydraulic and Geomorphic Analysis by Skillings- Connolly (Au List
1997 , Discussion of Skokomish River Valley Flood and Avulsion Hazards by Skillings-
Connolly ( September 1997), and the South Fork of the Skokomish River and Vance Creek
Hydraulic and Geomorphic Analysis and Recommendations for Action by Skillings-
Connolly (June 1999 , revised September 1999) have been completed and include general
documentation of the existence of avulsion risk areas . Further studies in the Skokomish
Flood Damage Prevention Ordinance- - February 24 , 2000
River floodplain are currently being undertaken under the authority of the Army Corps of
Engineers . Comprehensive flood control measures are necessary for public health safety
and welfare and W ZJaWP1Y60V1M11111vMLa1 COMM ne thire allow
property owners to protect their property .
1 '1 CST A T%TA A- " k TT !1T TT TT TI n!
-r- - J. - - - - - N - - - - JL - %- 0-
1 . 2 -2 It is therefore the purpose of this ordinance to promote the public health, safety, and
general welfare, and to minimize public and private losses due to flood conditions in
specific areas by provisions designed :
( 1 ) To protect human life, health and property;
(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; and
( 8 ) To ensure that those who occupy the areas of special flood hazard participate,
along with government, in assuming responsibility for their actions .-wrl ile at-time
Same tin those who occupy such areas ' the ability to responsibly
protect their property without arbittrary and recrinfinating goverivnentai action .
(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, Draft Lower South Fork and Upper Skokomish River
Hydraulic and Geomorphic Analysis, Discussion of Skokomish River Flood and
Avulsion Hazards and South Fork of the Skokomish River and Vance Creek
Hydraulic and Geomorphic Analysis and Recommendations for Action .
11 Provide for continued eli ig bil4 for FEMA Flood Insurance Program
1 . 34 METHODS OF REDUCING FLOOD LOSSES
In order to accomplish its purposes, this ordinance inrla&m provides regulatou methods
and provisions for :
( 1 ) Restricting or prohibiting uses which are dangerous to health, safety, and property
Flood Damage Prevention Ordinance--February 24, 2000 2
due to water or erosion hazards, or which result in damaging increases in erosion
or in flood heights or velocities ;
(2) Requiring that uses vulnerable to floods, including facilities which serve such uses,
be protected against flood damage at the time of initial construction;
(3 ) Controlling the alteration of natural floodplains, stream channels, and natural
protection barriers, which help accommodate or channel flood waters ;
(4) Controlling filling, grading, and other development which may increase flood
damage; and
( 5 ) Preventing or regulating the construction of flood barriers which will unnaturally
divert flood waters or may increase flood hazards in other areas .
(6 ) Controlling excessive erosion by constructing sound erosion control structures and
obtaining appropriate permits and exemptions from all applicable local, state, and
federal jurisdictions .
Implementing the recommendations of adopted flood hazard studies and plans .
SECTION 2 . 0
DEFINITIONS
Unless specifically defined below, words or phrases used in this ordinance shall be
interpreted so as to give them the meaning they have in common usage and to give this ordinance
its most reasonable application .
"A-ZONE" or "ZONE A" means those areas shown on the Federal Insurance Rate Maps (FIRM)
as that area of land within the floodplain which would be inundated by the 100-year flood .
"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 .
" APPEAL" means the right to request for a review of the Director of `_" ___ __a'_ Services
Community Development ' s interpretation of any provision of this ordinance 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" means the land in the floodplain within a community
subject to a one percent or greater chance of flooding on any given year . Designation on maps
Flood Damage Prevention Ordinance- =February 24, 2000 3
always includes the letters A or V . Areas of special flood hazard are designated as Frequently
Flooded Areas .
"AVULSION" means a sudden cutting off of land by flood, currents, or change in course of a
body of water .
" AVULSION RISK AREAS " include those areas generally identified in reports by Skillings-
Connolly as referenced in Section 1 . 2 of this chapter, and later studies, having the potential for
avulsion, which are related to the mapped. floodplain of the Skokon sh River; Vance Creek and
tributaries . Floodplain-related Avulsion risk areas are also designated in the Frequently Flooded
Areas chapter of the Mason County Resource Ordinance . Field confirmation shall be required
and documented within engineeringreports completed under Section 5 . 4 .
"BASE FLOOD" means the flood having a ( 1 ) percent chance of being equaled or exceeded in .
any given year . Also referred to as the " 100 -year flood . " 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 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, installations which produce, use, or store hazardous
materials or hazardous waste .
"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 . witIfin the area of special flood hazard ,
"DEVELOPMENT PERMIT" see definition for "Permit" under this chapter.
"DETAILED STUDY AREA" generally means that portion of the mapped floodplain for which
FEMA has performed a detailed study . Within Special Flood Risk Zone section 5 . 44 of this
Chapter. the Zone A2 floodplain of the Skokomish River and tributaries is referred to as the
Flood Damage Prevention Ordinance--February 24, 2000 4
"Detailed Study Area. "
"ELEVATED BUILDING" means for insurance purposesa nonbasement building which has its
lowest elevated floor raised above ground level by foundation walls, shear walls,12ost,Riers,
pilings, or columns .
"ENGINEERING REPORTS " 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 . Reports which address avulsion risk areas
shall include an avulsion risk analysis .
"FLOOD" or "FLOODING" means a general and temporary condition of partial or complete
I
nundation 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 .
"FLOOD PROOFING" means any combination of structural and non- structural 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 ,
Flood Damage Prevention Ordinance--February 24, 2000 5
"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 ordinance found at Section 5 . 24 (2) .
"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" .
"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 .
"MAXIMUM ALLOWABLE DENSITY" means the percentage of the total area of any lot
located in the Detailed Study Area of the Skokomish River floodplain, regardless of the size of the
lot, which all new development and substantial improvements shall not exceed .
"MAXIMUM ALLOWABLE OBSTRUCTION" means the maximum obstruction of a structure
allowable in the Detailed Study Area Zone A2 floodplain of the Skokomish River, to be calculated
as described herein .
"NEW CONSTRUCTION" means structures for which the " start of construction' commenced on
or after the effective date of this ordinance .
"NO NEW FOOTPRINT ZONE" is the general term used to identify those areas within the
floodplains of the Skokomish River and Vance Creek and tributaries and associated avulsion risk
areas.. where new construction following the effective date of this ordinance is restricted due to
the occurrence of high flood hazards Repair and substantial improvement shall be allowed
contingent on conditions described herein . Maps delineating No New Footprint Zones 1 -4 and
No New Footprint Zone I & and overbank flow paths are attached hereto as Exhibit A; Exhibit B
and Exhibit C . Site- specific locations of avulsion risk areas and overbank flow paths shall be
subject to confirmation in engineering reports completed under the authority of this chapter. See
also Section 5 . 4 -2 of this ordinance .
Flood Damage Prevention Ordinance- -February 24 , 2000 6
"OVERBANK FLOW PATHS " The Skokomish Comprehensive Flood Hazard Management
Plan, February 1997 by KCM identified overbank flow paths on the map dated February 21 ,
1997 entitled "Flood Hazard Areas; Recommended Acquisitions, " and attached hereto as Exhibit
C .
"PERMIT" means a written authorization from- lY Mason County General
S-e for any construction or development activity on all lands regulated by this ordinance .
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 Ordinance .
"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 .
"RECREATIONAL VEHICLE" means a vehicle which is :
Built on a single chassis ;
400 square feet or less when measured at the largest horizontal projection;
Designed to be self-propelled or permanently towable by a light duty truck; and
Designed primarily not for use as a permanent dwelling but as temporary living
quarters for recreational, camping travel or seasonal use .
, , sPFefAf:; f+7Eoof) f hkZARD AREA" ineans an area stit- 0 ect to a base or 100 year flood, are
Vi
of special flood hazard are shovyn on the flood insurance rate inap as Zone 2k AO , Af �30 , AE,
" SPECIAL FLOOD RISK ZONE" means that areaof the Zone A floodplain of the Skokon sh
River, Vance Creek and tributaries, and the Detailed Study Area Zone A2 floodplain of the
Skokomish River and tributaries, as identified Flood Insurance Rate Maps 530115 0175 D and
530115 0180 D , both dated December 8 , 1998 or as amended, including avulsion risk areas .
Valley identified by the Federai Eniergency Management Agency in the scientific study entitled
"The Flood insurance Study fbi- Unincorporated Areas Nfasotf % eonnnanity Panel inbe
530115 0180� Detailed Study Areal
" 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
Flood Damage Prevention Ordinance- -February 24, 2000 7
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 foundation 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 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 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 50 percent of the
market value of the structure before the damage occurred .
" SUBSTANTIAL IMPROVEMENT" means any repair, reconstruction, or improvement of a
structure, the cost of which equals or exceeds 50 percent of the market value of the structure
either :
( 1 ) Before the improvement or repair is started, or
(2) If the structure has been damaged and is being restored, before the damage
occurred . For the 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 .
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
(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 ordinance which permits
construction in a manner that would otherwise be prohibited by this ordinance .
"WATER DEPENDENT" means astructure -
use which cannot exist in other than a water front location and is dependent on the water by
reason of the intrinsic nature of its operations . Examples include but are not limited to cargo
terminal loading areas, barge loading , ship building repair, servicing and dry docking,
Flood Damage Prevention Ordinance- -February 24, 2000 8
aquaculture, log booming, dams for domestic/industrial water supple flood control and/or
hydroelectric production; water diversion structures and facilities for water supply, irrigation
and/or fisheries enhancement; flood water and drainage pumping_plants and facilities;
hydroelectric ,generating facilities and appurtenant structures ; and structural and non- structural
flood damage reduction facilities and stream bank stabilization structures and practices .
"WETLANDS "
VVaUU1 LdUIC; 16 usualty at ot tMat Luc; Sultauc; ut the land is coveted by shattow water VVICLiand .)
{Zj
f -
refer to the definition in the Mason County Resource Ordinance ,
SECTION 3 . 0
GENERAL PROVISIONS
3 . 1 LANDS TO WHICH THIS ORDINANCE APPLIES
This ordinance shall apply to all areas of special flood hazard and avulsion risk areas 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.
3 . 2 BASIS FOR ESTABLISHING THE AREAS OF SPECIAL FLOOD HAZARD
( 1 ) The areas of special flood hazard identified by the Federal Insurance Administration in
a scientific and engineering report entitled "The Flood Insurance Study for the Mason
County" dated February 5 , May 17 , 1988 , and revised December 8 , 1998 , with
accompanying Flood Insurance Maps, and any subsequent amendments thereto is hereby
adopted by reference and declared to be a part of this ordinance . The Flood Insurance
Study is on file at the Mason County Planning Department, Building_1, 411 N . 5th St . ,
Shelton, Washington .
(2) Floodplain related avulsion risk areas as defined in Section 2 . 0. indentified under the
provisions of Section 5 . 4 of this Chapter.
Flood Damage Prevention Ordinance--February 24 , 2000 9
3 . 3 PENALTIES FOR NONCOMPLIANCE
No structure or land shall hereafter be constructed, located, extended, converted, or
altered without full compliance with the terms of this ordinance and other applicable
regulations . Violation of the provisions of this ordinance 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
ordinance or fails to comply with any of its requirements shall upon conviction thereof be
fined not more than $ 1 , 000 imprisoned for not more than 60 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
section 15 . 13 provides for enforcement of violations to permits .
3 A ABROGATION AND GREATER RESTRICTIONS
This ordinance is not intended to repeal, abrogate, or impair any existing easements,
covenants, or deed restrictions . However, where this ordinance and another ordinance,
easement, covenant, or deed restriction conflict or overlap, whichever imposes the more
stringent restrictions shall prevail .
3 . 5 INTERPRETATION
In the interpretation and application of this ordinance, all provisions shall be :
( 1 ) Considered as a minimum requirements;
(2) Deemed neither to limit nor repeal any other powers granted under State statutes .
3 . 6 WARNING AND DISCLAIMER OF LIABILITY
The degree of flood protection required by this ordinance is considered reasonable for regulatory
purposes and is based on scientific and engineering considerations . Larger floods can and will
occur on rare occasions . Flood heights may be increased by man-made or natural causes . This
ordinance does not imply that land outside the areas of special flood hazards or uses permitted
within such areas will be free from flooding or flood damages . This ordinance shall not create
liability on the part of Mason County, any officer or employee thereof, or the Federal Insurance
Administration, for any flood damages that result from reliance on this ordinance or any
administrative decision lawfully made hereunder .
SECTION 4 . 0
ADMINISTRATION
Flood Damage Prevention Ordinance--February 24, 2000 10
4 . 1 ESTAELIS NT OF DEVELOPMENT PERMIT
4 . 1 - 1 Development Permit Required
A development permit shall be obtained before construction or development begins within
any area of special flood hazard established in Section 3 . 2 . The permit shall be for all
structures including manufactured homes, as set forth in the "DEFINITIONS , " and for all
development including fill and other activities, also as set forth in the "DEFINITIONS . " If
no other county_pern t is required, a floodplain permit shall be required .
4 . 1 -2 Application for Development Permit
Application for a development permit shall be made on forms furnished by t1h umour of
Mason County, which can be obtained from the Mason County Planning
Department and/or Permit Assistance Center . Application materials and may include but
not be limited to plans in duphr to triplicate drawn to scale showing the nature, location,
dimensions, and elevations of the area in question and existing or proposed structures, fill,
storage of materials, drainage facilities, and the location of the foregoing . Specifically, the
following information is required :
( 1 ) Elevation in relation to mean sea level, of the lowest floor (including basement) of
all structures ;
(2) Elevation in relation to mean sea level to which any structure has been
floodproofed ;
(3 ) Certification by a registered professional engineer or architect that the
floodproofing methods for any nonresidential structure meet the floodproofing
criteria in Section 5 . 2-2 ; and
(4) Description of the extent to which a watercourse will be altered or relocated as a
result of proposed development .
4 . 2 DESIGNATION OF THE PLANNING DIRECTOR OF
The Planning Director of 6eneral Services is hereby appointed to administer and
implement this ordinance by granting or denying development permit applications in
accordance with its provisions . The Planning Director may consult with other departments
and/or agencies with expertise to assist in permitting decisions .
Flood Damage Prevention Ordinance- -February 24 , 2000 11
4 . 3 DUTIES AND RESPONSIBILITIES OF THE PLANNING DIRECTOR �"]ENT" " A3
nr. n c �rrr n
Duties of the Planning Director of shall include, but not be limited to :
4 . 3 - 1 Permit Review
( 1 ) Review all development permits to determine that the permit requirements of this
ordinance have been satisfied .
(2) 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 .
(3 ) Review all development permits to determine if the proposed development is
located in the floodway, or special flood risk zone as defined in Section 2 . If
located in the floodway, assure that the provisions of Section 5 :3 are met . If
located in a special flood risk zone; assure that the provisions of Section 5 . 4 are
met .
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 om damage by the
elements. An "emergency " is an unanticipated and imminent threat to public
health, safty, or the environment which requires immediate action within a time
too short to allow °full compliance with this chanter. 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. "
4 . 3 -2 Use of Other Base Flood Data
When base flood elevation data has not been provided in accordance with Section 3 . 2,
BASIS FOR ESTABLISHING THE AREAS OF SPECIAL FLOOD HAZARD , the
Planning Director of 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 Section 5 . 2, SPECIFIC STANDARDS , and 5 . 3 FLOODWAYS , and 5 . 4
SPECIAL FLOOD RISK ZONE .
Flood Damage Prevention Ordinance--February 24 , 2000 12
4 . 3 -3 Information to be Obtained and Maintained
( 1 ) Where base flood elevation data is provided through the Flood Insurance Study or
required as in Section 4 . 3 -2, 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 .
(2) For all new or substantially improved floodproofed structures :
(i) verify and record the actual elevation (in relation to mean sea level) , and
(ii) maintain the floodproofing certifications required in Section 4 . 1 -2(3 ) .
(3 ) Maintain for public inspection all records pertaining to the provisions of this
ordinance .
4 . 3 -4 Alteration of Watercourses
( 1 ) Notify adjacent communities and the Washington State Department of Ecology
prior to any alteration or relocation of a watercourse, and submit evidence of such
notification to the Federal Insurance Administration .
(2) Require that maintenance is provided within the altered or relocated portion of said
watercourse so that the flood carrying capacity is not diminished .
4 . 3 - 5 Interpretation of FIRM Boundaries
Make interpretations Conduct field investigations where needed, �&s to verify the exact
location of the boundaries of the areas of special flood hazards (for example, where there
appears to be a conflict between a mapped boundary and actual field conditions) .
Following a field investigation , if Tthe person contesting the location of the boundary still
does not agree with the interpretation, they shall be given a reasonable opportunity to
appeal the interpretation as provided in Section 4 . 4 . 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 .
4A VARIANCE PROCEDURE
4 . 4- 1 Appeal Board
( 1 ) The Board of County Commissioners shall act as the Board of Appeals to hear and
decide appeals and requests for variances from the requirements of this ordinance .
(2) The Board of Appeals shall hear and decide appeals when it is alleged there is an
Flood Damage Prevention Ordinance-®February 24, 2000 13
error in any requirement, decision, or determination made by the Planning Director
Of %3MIM al Se, vices in the enforcement or administration of this ordinance .
(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 RCW Chapter 36 . 70 .
(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
ordinance, 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 the existing and anticipated
development;
(viii) the relationship of the proposed use to the comprehensive plan and flood plan
management program for that area,
(ix) the safety of access to the property in times of flood for ordinary and emergency
vehicles ;
(x) 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
(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, and water systems, and streets and bridges ,
xii 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 Section 4 . 4- 1 (4) and the purposes of this
ordinance, the Board of Appeals may attach such conditions to the granting of
variances as it deems necessary to further the purposes of this ordinance .
(6) The Planning Director of Eicneral Serw6ces shall maintain the records of all appeal
actions and report any variances to the Federal Insurance Administration upon
request .
4 . 4 -2 Conditions for 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
Flood Damage Prevention Ordinance- -February 24, 2000 14
existing structures constructed below the base flood level, providing items (i-xi) in
Section 4 . 44 (4) 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 regard to the procedures set forth in this section .
(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 Section 4 . 44 (4) , 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 .
(7) 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 4 . 4-2 ( 1 ) , and otherwise complies
with Sections 5 . 1 - 11 5 . 1 -2 and. 5 . 1 -3 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 .
Flood Damage Prevention Ordinance February 24, 2000 15
SECTION 5 . 0
PROVISIONS FOR FLOOD HAZARD REDUCTION
5 . 1 GENERALSTANDARDS
In all areas of special flood hazards, the following standards are required :
5 . 1 - 1 Anchoring
( 1 ) All new construction and substantial improvements shall be anchored to prevent flotation
collapse, or lateral movement of the structure .
(2) 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 damage .
Anchoring methods may include, but are not limited to , use of over-the-top or frame ties
to ground anchors (Reference FEMA' s "Manufactured Home Installation in Flood Hazard
Areas" guidebook for additional techniques) .
5 . 1 -2 Construction Materials and Methods
( 1 ) All new construction and substantial improvements shall be constructed with
materials and utility equipment resistant to flood damage .
(2) All new construction and substantial improvements shall be constructed using
methods and practices that minimize flood damage .
(3 ) 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 .
5 . 1 - 3 Utilities
( 1 ) All new and replacement water supply systems shall be designed to minimize or
eliminate infiltration of flood waters into the system;
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 ) ;
(2)(3 ) 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 ; and,
(3-)(4) On- site waste disposal systems shall be located to avoid impairment to them or
Flood Damage Prevention Ordinance--February 24, 2000 16
contamination from them during flooding .
5 . 1 -4 Subdivision Proposals
( 1 ) All subdivision proposals shall be consistent with the need to minimize flood
damage;
(2) All subdivision proposals shall have public utilities and facilities such as sewer, gas,
electrical, and water systems located and constructed to minimize flood damage ;
(3 ) All subdivision proposals shall have adequate drainage provided to reduce
exposure to flood damage; and,
(4) 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 5 acres (whichever
is less) .
Proposals for Subdivisions or Boundary Line Adjustments shall not result in any
lot which is nonconformingto o the provisions of this ordinance .
(6 ) Subdivisions located entirely within a floodplain shall not be allowed increased
density, through a Performance 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 re ug_ latory_provisions are met. When feasible, lots shall be clustered to
locate subdivisions outside the floodplain .
Q For proposed subdivisions of land within the Special Flood Risk Zone of the
Skokomish River Vance Creek and tributaries as defined in Section 2 of this
chapter, all the following provisions shall also apply:
0 Subdivision proposals shall meet the development provisions of this
Ordinance, including_provisions of Section 5 . 4 ; and
ii proposed development sites shall be on the highest ground available; and
iii engineering reports for the site under Section 5 . 4 shall include certification
that the private road access from public right-of-way to the development
site is not in an avulsion risk area. This provision shall also apply to
proposals where the development sites are outside the floodplain, but
access is through the floodplain, unless it can be shown that an alternate
access outside the floodplain is available and can be developed for the
proposed use .
5 . 1 - 5 Review of Building Permits
Were elevation data is not available either through the Flood Insurance Study or from
another authoritative source (Section 4 . 3 -2) , applications for building permits shall be
reviewed to assure that proposed construction will be reasonably safe from flooding .
Flood Damage Prevention Ordinance- -February 24, 2000 17
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 grade in these zones may result in higher insurance rates .
5 . 2 SPECIFIC STANDARDS
In all areas of special flood hazards where base flood elevation data has been provided as
set forth in Section 3 . 2, BASIS FOR ESTABLISHING THE AREAS OF SPECIAL
FLOOD HAZARD or Section 4 . 3 -2, Use of Other Base Flood Data, the following
provisions are required :
5 . 2 - 1 Residential Construction
( 1 ) 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 .
(2) Fully enclosed areas below the lowest floor that are subject to flooding are
prohibited, or shall be designated to automatically equalize hydrostatic flood forces
on exterior walls by allowing for the entry and exit of flood waters . 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 equipped with screens, louvers, or other coverings or devices
provided that they permit the automatic entry and exit of flood waters .
5 . 2 -2 Nonresidential Construction
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 level of the base flood elevation; or, together with attendant
utility and sanitary facilities, shall :
( 1 ) 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;
(2) Have structural components capable of resisting hydrostatic and hydrodynamic
loads and effects of buoyancy;
(3 ) 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
Flood Damage Prevention Ordinance- -February 24 , 2000 18
the structural design, specifications and plans . Such certifications shall be provided
to the official as set forth in Section 4 . 3 -3 (2) .
(4) Nonresidential structures that are elevated, not floodproofed, must meet the same
standards for space below the lowest floor as described in
5 . 2 - 1 (2) .
(5 ) 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 floodproofed to one foot above the base flood
level will be rated as the base flood level) .
5 . 2 - 3 Accessory Structures
Construction or substantial improvement of accessory structures, as defined in section 2 . 0,
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 :
( 1 ) A minimum of two openings having a total net area of not less than one square
foot of enclosed area subject to flooding shall be provided .
(2 ) The bottom of all openings shall be no higher than one foot above grade .
(3 ) Openings may be equipped with screens, louvers, or other coverings provided they
may permit the automatic entry and exit of flood waters .
(4) Structures shall not be designed for human habitation .
( 5 ) Structures shall be firmly anchored to prevent flotation which may result in damage
to other structures .
(6) Service facilities such as electrical and heating equipment shall be elevated or
floodproofed .
5 . 24 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 . 2 - 5 Manufactured Homes
All manufactured homes to be placed or substantially improved within Zones A1 -30, AH, and AE
Flood Damage Prevention Ordinance- -February 24, 2000 19
on the community' s FIRM 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 be securely
anchored to an adequately anchored foundation system in accordance with the provisions of
section 5 . 1 - 1 (2) .
5 . 2 - 6 Recreational Vehicles
Recreational vehicles placed on sites within Zones A1 - 30 , AH, and AE on the
community ' s FIRM shall either :
0i) Be on site for fewer than 180 consecutive days ;
ii Be fully licensed and ready for highway use, on its wheels or jai ckin system, be
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 5 . 2 .3 above and the elevation and anchoring
requirements for manufactured homes .
5 . 3 FLOODWAYS
Located within areas of special flood hazard established in Section 3 . 2 are the 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 ,
Valley as defined in section 2 . 0 :
( 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 analyses performed
in accordance with standard engineering practice that 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 (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, 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 comply with existing health, sanitary, or safety codes which have
been identified by the local code enforcement official and which was in existence prior to
the damage event or improvement or to structures identified as historic places shall not be
included in the 50 percent .
(3 ) If Section 5 . 3 ( 1 ) is satisfied, all new construction and substantial improvements shall
comply with all applicable flood hazard reduction provisions of Section 5 . 0 ,
PROVISIONS FOR FLOOD HAZARD REDUCTION .
Flood Damage Prevention Ordinance- -February 24, 2000 20
5 . 4 SPECIAL FLOOD RISK ZONE - FLOODPLAIN OF TIIE SKOKOMISH RIVER,
VANCE CREEK AND TRIBUTARIES , INCLUDING AVULSION RISK AREAS Vi
- , and 5 . 2 , f 41
(Sections (2) through (4) have been moved to section 5 . 4-5 ( 1 ) through (3)
( 5 ) 7NAly fill fli-ML, to "- Howed in the special flood risk zone shall be confined tL.%-,i "Metu"all
building site, other means of elevating structures sliail be encouraged such as posts, piles
and sty
(6) Solid road fills perpendicular to the flow of water are prohibited in tile special flood ris
zone . The graveling of driveways and other access roads is exempt ,
(7) To the extent f asible fills shall be compensated by cuts or extraction of like amounts o
materials to afleviate the effect of the fi+
(8 ) The ffighest portion of any lot shail be utilized as the building site . Lots partially III LILL/
special flood risk zone nrust comply with the regulations for the speciai flood risk zonc.
(9 ) Wlienever feasible, new structures shall be located iii the hydrattlic shadow of the existinrn
structures ,
( f 0) Fill fbr the elevation of stractlAires shall be prolfibited unless certification by a registered
professional architect is provided demonstrating that the fill shall not result in
0 F in flood levels daring the occurrence of the base flood discharge7
5 . 4 . 1 A Special Flood Risk Zone is hereby established for the Zone A floodplain of the
Skokomish River, Vance Creek and tributaries, and the Detailed Study Area Zone A2
floodplain of the Skokomish River and tributaries, and avulsion risk areas as defined in
Section 2 . 0 .
Flood Damage Prevention Ordinance--February 24, 2000 21
5 . 4 -2 No New Footprint Zones
No new footprint zones are hereby established for the Special Flood Risk Zone as
follows :
0 No New Footprint Zones delineated in the Skokomish River
Comprehensive Flood Hazard Management Plan. February 1997, as
Zones 1 2, 3 , & 4, attached hereto as Exhibit "N '.
ii Zone IA, which was originally delineated in the Draft Skokomish River
Comprehensive Flood Hazard Management Plan April 1996, attached
hereto as Exhibit `B " .
iii All portions of the Detailed Study Area Zone A2 floodplain of the
Skokomish River and tributaries where the existing site elevation is more
than 2 feet below the Base Flood Elevation as identified by FIRM map and
as certified by a licensed engineer or surveyor .
iv All avulsion risk areas_ and all overbank flow paths shown in exhibit C .
Engineering reports shall be required for site- specific field confirmation and
documentation as necessary. The following information shall be used to
determine if an engineering report is necessary :
(a) Avulsion-related studies completed to date, and
(b) Site review and consultation with a county engineer to assess
applicability of studies to the site for determining if this is in or
alongside a potential avulsion area, or if an engineering report is
required for a determination .
New construction shall not be allowed in No New Footprint Zones . Repair and
substantial improvement may be allowed providing that the following conditions
are achieved :
0 The area of the footprint(s) of the structure( s) following reconstruction
shall be no greater than the area(s) of the footprints prior to
reconstruction . A footprint is defined as the total area of the first floor of a
structure, regardless of how the structure. is supported .
(ii) Any substantial improvement of the structure shall also meet the general
standards presented in this chapter.
5 . 4 - 3 New construction and substantial improvements may be allowed within the Special
Flood Risk Area where the following provisions are met :
O The structure is at least 200 feet from the Ordinary High Water Mark of a stream
or river, provided that if setback is from We 2 - 5 streams and all other provisions
of this ordinance are met, where a proposed development location is supported by
an avulsion risk engineering report, the minimum setback sould be as provided for
within other applicable regulations; and
b The proposed development is not in a No New Footprint Zone as defined in
Flood Damage Prevention Ordinance--February 24 , 2000 22
Section 5 . 4-2 . A report from a professional engineer as defined in Section 2 . 0 has
determined that the proposed development is not within an avulsion risk area or
overbank flow paths ; and
c) if located within the Detailed Study Area Zone A2 floodplain of the Skokon sh
River and tributaries the development meets the requirements of Section 5 . 44 :
All new construction and substantial improvements shall also meet the GENERAL
STANDARDS presented in Section 5 . 1 and SPECIFIC STANDARDS presented in
Sections 5 . 2- 1 through 5 . 2-6 .
5 . 44 Within the Detailed Study Area Zone A2 floodplain of the Skokomish River and
tributaries (referred to below as the "Detailed Study Area"), new construction and
substantial improvements may be allowed where not otherwise prohibited and all of the
following provisions are met :
Location : All new construction and substantial improvements shall be located on
the highest existing ground available . The Administrator, on a case-by- case basis
may allow development on areas other than the highest existing ground available
when it can be demonstrated that such location will not increase the flood hazards
to the structure or adjacent properties . In making a determination the
Administrator shall consider the size of the parcel, proposed access locations,
proximity to other structures and any conflicts with setback requirements of this
chapter, and may require a report from an engineer which addresses the flood
hazard risk .
Maximum Allowable Density for all development on a lot in the Detailed Study
Area : To assure that new development and substantial improvements combined
with existing development, will not cause a cumulative increase in the base flood
elevation of more than one half (0 . 5 ) foot, all new development and substantial
improvements shall be limited as follows :
.Q The footprint of any proposed use or development regulated under this
chapter that will displace flood waters, combined with existing
development, shall not exceed three (3 ) percent of the land area of that
portion of the lot located in the Detailed Study Area ,
Maximum Allowable Obstruction for all development in the Detailed Study Area :
The maximum width (sum of widths) of all existing and proposed
structures and other development shall not exceed seventeen ( 17) percent
of the length of the line drawn perpendicular to the known flood water
flow direction at the point where the development(s) is located . The length
of said line shall not extend beyond the property boundary or the edge of
Flood Damage Prevention Ordinancem ®February 24, 2000 23
the Detailed Study Area, whichever is less .
Where structures are to be constructed on adjacent parcels five (5 ) acres or
less in size, the building setback shall be 41 . 5 percent of the line drawn
perpendicular to the known flood water flow direction at the point where
the development(s) is located . For example; for a 2 1 /2 acre square parcel
(i . e . 330 x 330 ft) with the flood flow perpendicular to the property lines,
the building setback would be 137 feet with the maximum allowable width
or sum of widths being 56 feet . See Appendix A for example drawing_
Oc Setback requirements for development on parcels larger than five (5 acres
shall be evaluated on a case-by-case basis to determine reasonable. setbacks
that allow for the safe conveyance of flood waters without increasing flood
hazards or risks to surrounding properties . The Administrator shall
consider the following in making; a setback determination :
0 the proximity of the proposed structure to existing and anticipated
development;
ii the width of proposed structure perpendicular to flood water flow,
iii topography of the site and surrounding area;
iv effect of proposed structure on flood water levels in the immediate
area such as backwater effects and redirection
(y) the existing and potential development along the cross- section line
perpendicular to flood water flow as it relates to the maximum
allowable obstruction of seventeen ( 17) percent ,
Orientation : All new construction and substantial improvements are required to
minimize the cross- sectional area perpendicular to known flood water flow
patterns . Determination of flood water flow direction for such orientation shall be
based upon topographical and historical flood data on file with the administrative
official . When such information is not available, such orientation of the reg atest
cross- sectional area shall be in an upstream-downstream direction at a right angle
to a line drawn along the shortest distance from the midpoint of the river channel
through the midpoint of the lot.
5 . 4- 5 Dikes Levees and Other Water Flow Modification Structures
(2 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 .
Control
Flood Damage Prevention Ordinance- -February 24, 2000 24
(3)(4 Maintenance to existing legally established 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 , and 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 re ug latory_permit processes .
(4j( 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 .
Activities related to the repair, maintenance or construction of bank stabilization, dikes,
levees or other related development are a permit required activity under Chapter 4 . 1 of
this ordinance, are subject to all provisions for development standards within this
ordinance, and shall provide for appropriate inspections during and following; construction
and/or repair. Construction shall meet MRCS standards, as recommended within the
Skokomish River Comprehensive Flood Hazard Management Plan, or as revised .
W Projects proposed by government agencies under this chapter as recommended within the
Skokomish River Comprehensive Flood Hazard Management Plan, or SkillingsJ.
and
Connolly studies dated September 1997 , and September 1999, shall be evaluated on a
case-by-case basis . The Administrator shall include the following considerations in
making; an evaluation :
(i) Recommendations of applicable study;
ii Provisions of this chapter;
(iii)Project- specific engineering;
(iv)Public benefit;
O All applicable regulations .
Flood Damage Prevention Ordinance--February 24 , 2000 25
and stoiftM c r�ix ge-
section.
aL
These goals and objectives as well as other convanents and concerns have been recognized and
( f ) To maintain tile L I V %W1 III IL-a pi esent channel in a way as to alleviate flooding conditions r
throughout the vailey resulting in reduced flood damages to ail e)dsting structures ,
(2) To protect stream batiks with approved stabilization methods that Control excessive erosion
(3 ) To perfbi-in proper river chamiel maintenance includitT the maintenance of dikes, drainage
ditches, and potential flow obstructions resulting in reduced flood damages-7
(4) To maintain and enhance fish and wildlife habitat .
Flood Damage Prevention Ordinance--February 24, 2000 26
APPENDIX A
AV ?ox I Adapted omo. ' Comprehensive
:a L:�7�Fg.. :* ' 4. a�;i. Flood z rd Management Plan
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_ , 1TACHMENT C
17 . 01 . 090 FREQUENTLY FLOODEDAREAS
The purpose of this Section is to prevent the potential for further aggravation of flooding problems and
to guide development in areas vulnerable to flooding .
A . CLASSIFICATION
The following shall be classified Frequently Flooded Areas :
Frequently Flooded Areas are identified by the Federal Emergency Management Agency as
those areas within the 100 year floodplain in a report entitled "The Flood Insurance Study for
Mason County " dated May 17 , 1988 , and revised December 8 , 1998 , with accompanying
Flood Insurance Rate Maps, and any subsequent amendments thereto , and should be utilized as
a guide to development .
The Skokomish River and floodplain as shown in the Comprehensive Flood Hazard Management
Plan for the Skokomish River, February 1997A
Avulsion risk areas as identified under the provisions of the Mason County Flood Damage
Prevention Ordinance .
B . DESIGNATION
Lands of Mason County meeting the classification criterion for Frequently Flooded Areas are
hereby designated , under RCW 36 . 70A . 060 and RCW 36 . 70A . 170 , as Frequently Flooded
Areas requiring immediate protection from incompatible land uses .
C . LAND USE
1 . Land uses in Frequently Flooded Areas shall be in compliance with the applicable
provisions and requirements of all ordinances as referenced in Section 17 . 01 . 050 , or as
amended and undated .
subject to the following Development Standards .
2 . Permitted Uses in the Belfair Urban Growth Area
Hereafter all buildings, structures , or parcels of land within frequently flooded areas
shall only be used for the following unless otherwise provided for in this ordinance :
a . Agriculture and aquaculture practices ;
b . Forest practices ;
c . Outdoor recreation and parks ;
d . Single-family residential limited to 1 dwelling unit per acre .
3 . The following uses within Frequently Flooded Areas are subject to conditional use
permits :
a . Radio and transmission towers, resource based industries, schools , trailer- mix
concrete plants , sawmills, marinas , fire stations , fuel storage tanks , and
commercial outdoor recreation .
b . Other uses and activities determined by the Director and the Health Director
that are likely to pose a threat to public health , safety , and general welfare if
located within a frequently flooded area ,
D . DEVELOPMENT STANDARDS
Mason County Flood Damage Prevention Ordinance provides specific regulations and permit
requirements for development conducted within the frequently flooded areas of Mason Count
,
VVIIUII
�:'flooded �
frequently flooded areams�.
Subdivisions located el-i-LIlUly VVILIIIII 0 IIUqUUIILIY . . . . . ..d area sia not be allowed
i
Fill shall only be used if into reasonable alternative h s available stich as elevating
ipoles , or vvalls�.
am A Density Flood Fringe is heieby established for the SkokomiMi R veI and
floodplain as studied in the Comprehensive Flood I lazard Management Plan For
the Skokomish Skokomish River Density Flood Rhige
attached heieto as Exhibit " B " and made a part of this code bV refelelice . A "
development vv N thin the Dens E ty Flood Fiinge shall comply with the following
01,00siarrs.
hid to be located on the highest existing ground e . The
Administrator , on a case=by�case basis may allow devefo��
areas other th " ll 1,15� existing ground available IL Lo011 UU
Location . A " new constraction and substantial inipiovenients are
InL All
Frequently Flooded Areas Chapter 17 . 01 . 090 of Resource Ordinance , February 24 , 2000
of all new
�s or other
Shall !IM V^ LUIIU 1LPV5yUIIU Lilt; [XILIPUTLY IJLTUliU (3 [ y VI Lilt; C;UYV5 Ul Lilt;
Lilt; PIUPUILY 0
Setback requirements fop, development on parce ' s larger tham"I
acres sha " be evaluated on a case +ysmease basis to d � III IV
without increasing flood hazards or risks to surrounding properties . Th�.w
detenninati V I 1 e
the proximity of the proposed structure to existing
ant In pated �dev � l � vlil � IILF
the vvidth of proposed structuie perpendiculai to flood water
ov r
topography of the site and surrounding area ;
( i V ) effect of proposed structure on floodnat. , All the
_ .
� mmcai � Gtc area such as backwater effects and
_ J ' _ _ _ a : _ ._ r
(v ) the existing and potential U � V � JWPIIIUIJL a ong the cross-section
VIA It
11 � �G V Ytl GU 0. 11GJG QI GQJ .
•
Frequently Flooded Areas Chapter 17 , 01 . 090 of Resource Ordinance , February 24 , 2000
1110 MICRO—UT- Lilt; IVULIJIML UN LIM ZOLIULP IUIIUVVIIIV
LP, � P-P,L . PAP � . . X
IVLPrUIIZOLIULvIP 9WICIII LJO IIU VIVOLVI L1143OR Lilt; Olt; CI %5 Ul Lilt;
IVULPKIIIL jJIIUI LU I45LoUII0LItICti6l1m
A r I -
IPPILlay PPP;U "� LM I LICI I AIIIpKVVVIIIVIIL Ul Lilt; ZOLIULILUIV 011011 Invu"her
n ec� on
!JVIIVIOI OLOIIUCIIUO PIVOVIILC;U 0 LI PPJu LIIIUUvII %PICOCLIP ull
l"P IPP. . . . M . . . . . . w
Lim I luuu " 011iclut; v 1UNIUMIton Ordinance- RNIM 59 941s
dP All
%P.P. IUIlm lm% li IIC; VV koPUIIZ3LIU %.PrLIVII OIIU %>UUZOL01 I LICK [ hnpiuvemerfts��
115LJUIIUU LU IIIIIIIII ]MC LIYV LIU [ ICII GIVO PuipullUILOUICII LU MIJUVVIJ
floodwatei flovv patterns . of floodvvatV,mr " w, -v-V- 0111MIP
I- - -I - IPPPPP � . � A
for suCII UIIUIILULIWII Z)11 (311 LIU LJCIOC;U UPVII LUPUYI .CiplilLoOl OIIU 111OLUITUCII
xl . . � m. X' I . -& � � 1AILP,
IlUVU LIP VII lilt; VVIL11 IP ctunimmuCKLIV Z; Ul I ILP v v I len-�S�
a . -. . -� . - - � I I . 1. 1 . � - - � L.- � -. ! � � PAP� � � . 9 & � . . . . - � - -� - - - - -
inForma- P'L101-1 1 � IIWL UVCIIICILP OULP11 UIIC; IILCILIUII Ul Lilt; YICCFLVPZSI—V��
I LPP . ! .. � . . � �
. Sect onal area � 11 %;Ptll LIFE; III all UPOLIVOIll ""UVIIVII01. 1150111 UIIC; LoLIUII CIL 0 IIyIIC
� . . 1 , -. . BI- - - I- - - A - - a � z
CII lylt; LV Cl Ili IV Ul CIVVI I CMIUI ly--EIFTU� L.. . distance from the- 1-1-11OU'poilli, VIP
1.11c; IIV . , . 11 . 11nel through thle 11,,Of tile lot .
Inx
III Lilt; OVOIRL UC; VC; IUPIIIC; IIL Ull C1 IUL LIP IIUL IUIIY ULIIIZV IP Ili -
V � PPILP _ x OP � I- - P,: . L.P X � � &� I I
0111.1 " ClUlu IUL -LfvvqulclyK; Ul %wP /Vj LIIV UVVVIVPIIIVIIL lIylILO IVI 1,11
area slICIII DIUL UV UCIIIq;:I4 %.jr1j " b1eq;
ATTACfflTENT D
Revisions to Chapter 17 . 01 . 240 DEFINITIONSs follows .
Frequently Flooded Areas : Lands in the floodplain subject to a one percent or greater chance of
flooding in any given year , including floodplain related areas of avulsion risk . These areas include , but
are not limited to , streams , rivers , lakes , coastal areas, wetlands and the like .
IMILP�IMUVV F- UULPRIIIL d20-1-110- -m An area vy thin a dens ty fl0od fringe where new constraction follovViM + kM
effect ve date of this ordwnanc .- is M- 34,19 � L�� � W � lw� the occuirence of high floodlyarards�.
Reconstruction shall be allowed contingent on conditions described��.�
Definitions Chapter 17 . 01 . 240 of Resource Ordinance February 24 , 2000