HomeMy WebLinkAbout04-21-2020 PLANNING COMMISSIONPlanning Commission Meeting
April 21, 2020 - 7:00 P M
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B .RO L L C AL L/E S TAB L I S HM E NT O F Q UO RUM
C.P L E D G E O F AL L E G I ANC E
I I I .AP P RO VAL O F M INUT E S
A .March 3, 2020 Draft Minutes from the P lanning Commission Regular Meeting
I V.P UB L I C HE ARI NG S
A .Z O A19-0004, Proposed F loodplain Code Amendments to A C C 15.68, 'Flood Hazard
A reas'.
P ublic Hearing on amendments to remain consistent with the latest F E MA model
Page 1 of 117
ordinance and to coincide with separate F E MA adoption of updated Federal I nsurance
Rate Maps (F I R M)
V.O T HE R B US I NE S S
V I .C O M M UNIT Y D E V E L O P M E NT RE P O RT
Update on Community Development Services activities.
V I I .AD J O URNM E NT
The City of Auburn Planning Commission is a seven member advisory body that provides
recommendations to the Auburn City Council on the preparation of and amendments to land
use plans and related codes such as zoning. Planning Commissioners are appointed by the
Mayor and confirmed by the City Council.
Actions taken by the Planning Commission, other than approvals or amendments to the
Planning Commission Rules of Procedure, are not final decisions; they are in the form of
recommendations to the city council which must ultimately make the final decision.
Page 2 of 117
AGENDA BILL APPROVAL FORM
Agenda Subject:
March 3, 2020 Draft Minutes from the Planning Commission
Regular Meeting
Date:
April 7, 2020
Department:
Community Development
Attachments:
March 3, 2020 Draft Minutes from the Planning
Commis s ion Regular Meeting
Budget Impact:
Current Budget: $0
Proposed Revision: $0
Revised Budget: $0
Administrativ e Recommendation:
Planning Commission review and approve the March 3, 2020 regular meeting minutes.
Background Summary:
Rev iewed by Council Committees:
Councilmember:Staff:Dixon
Meeting Date:April 21, 2020 Item Number:
Page 4 of 117
PLANNING COMMISSION
March 3, 2020
Draft MINUTES
I. CALL TO ORDER
Chair Judi Roland called the meeting to order at 7:00 p.m. in Auburn City Council
Chambers located at 25 West Main Street, Auburn, WA 98001.
a.) ROLL CALL/ESTABLISHMENT OF QUORUM
Commissioners present: Chair Judi Roland, Vice-Chair Lee, Commissioner Mason,
Commissioner Moutzouris, and Commissioner Stephens. Commissioner Khanal was
excused.
Staff present: Jeff Dixon, Planning Services Manager; Doug Ruth, Assistant City
Attorney; Steve Sturza, Development Engineer Manager; Jennifer Oliver, Admin
Assistant.
Members of the public present: Brianna Thomas
b.) PLEDGE OF ALLEGIANCE
II. APPROVAL OF MINUTES
A. January 7, 2020 – Regular Meeting Minutes
Vice Chair Lee moved and Commissioner Stephens seconded to approve the
minutes from the January 7, 2020 meeting as written.
MOTION CARRIED UNANIMOUSLY. 5-0
B. February 4, 2020 – Regular Meeting Minutes
Commissioner Stephens moved and Commissioner Moutzouris seconded to
approve the minutes from the February 4, 2020 meeting as written.
Vice Chair Lee did not attend the February 4, 2020 meeting and did not vote.
MOTION CARRIED UNANIMOUSLY. 4-0
Page 5 of 117
PLANNING COMMISSION MEETING MINUTES March 3, 2020
Page 2
III. OTHER BUSINESS
A. Floodplain Code Update
Introduction of draft amendments to Auburn City Code Chapter 15.68, Flood Hazard
Areas.
Staff member Steve Sturza, Development Engineer Manager, gave the Planning
Commission a presentation on the Floodplain Development Code Update.
In February 2020, the Federal Emergency Management Agency (FEMA) sent a
Letter of Determination to confirm that the final Base Flood Elevations (BFE’s) and
Flood Hazard Determinations (FHD’s) will be published in the Federal Register as
soon as possible. The modified BFE’s, FHD’s and revised map panels, as
referenced, will be effective as of August 19, 2020.
The National Flood Insurance Program was created by the National Flood Insurance
Act of 1968. Participation is voluntary. If participation is completed, the benefits
consists of Flood insurance, Grants and Loans, Disaster Assistance and federally
backed mortgages. The Goals for the National Flood Insurance Program (NFIP) are:
• Save lives and protect property
• Offer low cost flood insurance
• Encourage a comprehensive approach to floodplain management
• Puget Sound area- protect Endangered Species.
The Commission questioned if individuals owning property in the floodplain would
still purchase their own insurance or would the City do that for them. Staff confirmed
that the individuals would purchase the flood insurance on their own but may be
required by their mortgage lender.
The Commission mentioned that they would like to see a map of the floodplain areas
where the changes will take place. Staff responded that there are maps available
and would look into GIS and provide the maps for the Commission.
Not amending the ordinance could result in:
• Suspension of NFIP eligibility
• No mortgages or home equity loans in floodplain areas
• No renewals of existing flood insurance policies
• Loss of most forms of Disaster Assistance
• No federal grants or loans
• Loss of subsidized insurance for Pre-FIRM structures
• Potential impacts to Endangered Species
• Failure to communities to properly regulate flood hazard areas may bring
lawsuits.
The benefits of Flood Insurance consists of insurance claims are paid with no
disaster declaration; 20-25% of insurance claims are outside the map flood area,
insurance cannot be canceled for repeat losses, insurance is available to renters and
owners and a loan will be repaid with interest.
The NFIP Roles for Federal and State consists of:
• Federal – FEMA
o National program oversight
o Flood Insurance Rate Mapping
o Establish development/building standards
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PLANNING COMMISSION MEETING MINUTES March 3, 2020
Page 3
o Provide Insurance Coverage
• State – Department of Ecology
o State program oversight
o Establish development/building standards
o Provide technical assistance to local communities/agencies
o Evaluate and document floodplain management activities
NFIP Roles for Auburn
• Adopt and enforce floodplain management ordinance compliant with
Federal/State laws
• Permit of deny development activities in the regulated floodplain
• Inspect development in the regulated floodplain
• Maintain records of all development in the regulated floodplain
• Make substantial damage determinations
• Ensure all permits are obtained from other government agencies when they
are needed in the regulated floodplain
• Development oversight in the regulated floodplain is the City of Auburn’s
responsibility
Staff displayed on the screen a Flood Insurance Rate Map for the Commission that
determines where, if any, flooding were likely to occur. The Commission asked if a
homeowner were to purchase flood insurance, will the insurance companies consult
this map to determine if you need flood insurance. Staff confirmed that they would
consult the map and figure out if the home is in the floodplain. Commissioners
inquired if this applied to new buildings or existing buildings and Staff responded that
it is for both.
Staff continued with the presentation showing additional maps showing preliminary
vs. effective FIRMs. The map indicates current effective FIRMs as of May 1995 and
Preliminary FIRMs as of August 2020. Staff went on to confirm that all development
in the regulated floodplain requires issuance of a floodplain permit. Per FEMA,
Development means any unnatural change to improved or unimproved real estate in
the Special Flood Hazard Area (SFHA), including but not limited to buildings or other
structures, mining, dredging, filling, grading, paving, excavation or drilling operations
or storage of equipment or materials.
Federal Minimum Requirements
• Require permits in Special Flood Hazard Area (SFHA) as shown in the
FIRM’s issued by FEMA
• Development in Floodway is not allowed for single family residential and it’s
difficult for commercial development
• Foundations are allowed as long as there are openings to resist hydrostatic
pressure
• Enclosed spaces can only be used for parking, access, and limited storage
• Residential buildings: lowest floor, including basement, elevated to or above
BFE
• Non-residential buildings: elevated or flood-proofed
• No increase in Base Flood Elevation for development within SFHA
• Utilities must be waterproof, anchored, and/or elevated
Page 7 of 117
PLANNING COMMISSION MEETING MINUTES March 3, 2020
Page 4
Staff referred to the draft strike-thorough and underline changes proposed to ACC
15.68 to remain consistent with the latest Model Ordinance from FEMA.
This draft was created from the State of Washington Model Flood Damage
Prevention Ordinance; as reviewed and modified by City of Auburn Community
Development and Public Works; and has been reviewed by FEMA and Department
of Ecology. On March 2, 2020 Additional Comments were received from Department
of Ecology and staff is still working through these comments and waiting for a
response from Dept. of Ecology regarding questions that staff has.
In addition changes to be consistent with model ordinance, Staff proposes changes
based on their experience implementing the regulations. These include: Reorganize
ACC, Chapter 15.68 to correspond to the layout of the Model Ordinance;
Update the definitions section to have the latest definitions per NFIP, NMFS, FEMA,
DOE and City of Auburn; Remove all of the permit application submittal criteria from
ACC, Chapter 15.68; Information already provided in ACC 18.70.025 for variances is
removed to avoid redundancy; Minimum 15-foot setback from the protected area;
Remove a date for assessing cumulative improvements; Increasing the requirements
for what is to be addressed in Habitat Mitigation Plans.
Staff Proposed updates to ACC 15.68 Ripairian Buffer Zone
A map was displayed to the Planning Commission that showed the Channel
Migration Zone, the 100-year Floodplain, Floodway and Riparian Habitat Zone.
Staff Proposed updates to ACC 15.68 Channel Migration Zone
A map was presented to the Commission showing the Channel Migration Zone.
The code changes would include a reference to the FIRM’s that are simultaneously
being revisedby FEMA.
The Commission deliberated and commented that the text showing the changes with
the redlines is somewhat difficult to read. They asked what the red lines and the
black text represents. Staff responded that the black text are the current code and
the red lines are code changes representing deleted or added text to restructure the
code.
Chair Roland asked who the Floodplain Administrator is and Steve Sturza,
Development Engineer Manager responded that Community Development Director,
Jeff Tate takes on that role for the City.
The Planning Commission inquired if there will be a Public Hearing and Planning
Services Manager; Jeff Dixon responded that yes, that the purpose of tonight’s
presentation is a briefing to introduce the code changes. The next step is for Staff to
send out to the Public Notice and then proceed to schedule a Public Hearing at the
April Planning Commission Meeting.
The Commission requested that in advance of the hearing, maps be provided to
further understand the area where the changes will happen. Using the screen in the
room, Staff brought up the GIS system map to show an overall view of what is
changing. The Planning Commission requested to receive a clean copy of a map of
what the changes will consist of and where they will be. They agreed this would help
Page 8 of 117
PLANNING COMMISSION MEETING MINUTES March 3, 2020
Page 5
them to understand the information better. Staff will supply a map for the
Commissioners prior to the next meeting. Staff will also highlight any further text
changes based on the very recent comments received by the City.
B. Review of Planning Commission Rules of Procedures
Annually the Planning Commission reviews their Rules of Procedure and
determines if any changes are warranted.
The Planning Commission’s ‘Rules of Procedure’ were last amended on
March 5, 2019. Annually, the Planning Commission reviews their Rules of
Procedure (Rules) as a content reminder and also to consider any
modifications of the Rules. A draft of some relatively minor, housekeeping
type changes were identified by Planning Dept. Staff and distributed in
advance of the Planning Commission’s January 7, 2020 meeting.
These changes included:
• Capitalization
• Correcting the Community Development Dept. name
• Correcting a reference from “Council” to “Commission” to be accurate
• Clarifying Findings of Fact
• Changing the section numbering to agree
The Planning Commission reviewed and discussed these changes at their
previous meetings.
Additionally, at their January meeting the Legal Dept. Staff distributed some
further changes to the Rules based on recent changes to the City Council’s
Rules of Procedure. The Legal Dept. Staff reviewed these at the meeting and
offered to research the use of disruptive language and instances of how it
was handled.
Then in February these changes to Section X. ‘Public Hearings’ (Pages 9-10),
include changes to:
• Recognize that not voting is counted as negative vote
• Clarify that the Chair, Member, or Secretary can call for a roll call or
hand vote.
• Clarify procedures for abstaining from a vote due to a conflict of
interest.
And changes to Section XI. ‘Conduct’ (Page 11), to:
• Further elaborate on what constitutes “disruption”
Staff Recommendation:
Page 9 of 117
PLANNING COMMISSION MEETING MINUTES March 3, 2020
Page 6
A draft based on input from both the Planning and Legal Depts. is provided
for the Planning Commission’s consideration. This latest draft shows
changes in strike-through (deletions) and underline (additions). If these
changes are satisfactory, the Commission can approve.
If the Planning Commission has additional changes, these can be captured by
staff and then these changes can be presented in writing and provided at the
next regular meeting as provided in Section XIII, ‘Amendment’.
The Commission deliberated and inquired if a meeting were to become
disruptive from the public, can it be relocated . Assistant City Attorney, Doug
Ruth confirmed that is can be moved as well as cancelled. The Assistant City
Attorney added that these subject have been evolving and are related to first
amendment right of free speech.
Commissioner Moutzouris motioned and Vice Chair Lee seconded to approve
the updated Planning Commission Rules of Procedures.
MOTION CARRIED UNANIMOUSLY. 5-0
IV. COMMUNITY DEVELOPMENT REPORT
Planning Services Manager, Jeff Dixon reported to the Planning Commission that
the Legacy Project, which is located across the street from City Hall, is close to
getting their building permit and civil plans approved. Building construction
should begin within the next few weeks.
Also, the Auburn School District is working with Community Development Dept.
on their plans for redevelopment for Chinook and Lea Hill Elementary schools.
At the last Planning Commission meeting, the Commission inquired on activity at
Mobile home park that is located within the City of Pacific city limits. Planning
Services Manager, Jeff Dixon has reached out the City of Pacific to see what the
status is and he has not received any word back from them prior to the meeting.
The Commission inquired about the Heritage Building Site status and where the
City and the owner are at with the permits. Staff responded that the City and the
owner are still working through the permitting and making further changes to the
building design.
Commissioner Stephens asked about the former property that previously housed
the business,; English Gardens. Staff quired the permit application records i for
that particular site and at this time, there are not applications for redevelopment
of the site.
Page 10 of 117
PLANNING COMMISSION MEETING MINUTES March 3, 2020
Page 7
The Planning Commission inquired about the old Key Bank site and what will be
going in there. Planning Services Manager, Jeff Dixon remarked that it is going to
be divided into two tenant spaces, one being a 7-11 convenience store. The
project is subject to the city’s Design review process but work has started
because as a bank of a very heavy safe that the floor did not support.
The Commission and Staff discussed the procedure for distribution packets and
mailing them out instead of delivering to their homes. The Planning Commission
agreed that this is amenablebut Staff explained that during the Comp Plan
Amendment timeframe, or otherw when the packet is particulary large the packet
may continue to be dropped off at their homes and not mailed.
Next meeting confirmed is April 7, 2020 at 7:00 p.m.
V. ADJOURNMENT
There being no further business to come before the Planning Commission, Chair Roland
adjourned the meeting at 8:12 p.m.
Page 11 of 117
AGENDA BILL APPROVAL FORM
Agenda Subject:
ZOA19-0004, Proposed Floodplain Code Amendments to
ACC 15.68, 'Flood Hazard Areas'.
Date:
April 7, 2020
Department:
Community Development
Attachments:
Memorandum
Comments from Dept of Ecology
Ch 15.68 ACC Draft Changes - Clean Version
Ch 15.68 ACC Draft Changes - Track Changes
Floodplain Planning Commis s ion Pres entation
Budget Impact:
Current Budget: $0
Proposed Revision: $0
Revised Budget: $0
Administrativ e Recommendation:
Background Summary:
See Attached Memorandum
Rev iewed by Council Committees:
Councilmember:Staff:Dixon
Meeting Date:April 21, 2020 Item Number:PH.1
Page 12 of 117
MEMORANDUM
TO: Judi Roland, Chair, Planning Commission
Roger Lee, Vice-Chair, Planning Commission
Planning Commission Members
FROM: Steven Sturza, PE, CFM, Development Engineer Manager,
Department of Community Development
DATE: April 21st, 2020
SUBJECT: Planning Commission to Conduct Public Hearing on proposed Floodplain
Development Code Revisions (ACC 15.68, ‘Flood Hazards’, to be retitled ‘Floodplain Development
Management’)
PURPOSE
Public Hearing conducted by Planning Commission regarding policy updates to the City’s
Floodplain Development Code adopted in 2010 to comply with the current requirements set by
the National Marine Fisheries Services’ (NMFS) Biological Opinion, the National Flood Insurance
Program (NFIP) in Western Washington, and Federal Emergency Management Agency (FEMA).
BACKGROUND
The City of Auburn is a participating community in the National Flood Insurance Program
(NFIP). In 2010, the NMFS issued a Biological Opinion (referred to in this memo as the “Bi-Op”)
which concluded that continued implementation of the NFIP in the Puget Sound (Western
Washington) region adversely affects the habitat of certain threatened and endangered species
listed under the federal Endangered Species Act (ESA). The Bi-Op required changes to the way
the NFIP is implemented in order to meet the requirements of the Endangered Species Act
(ESA).
In 2010, a model floodplain management ordinance was published by FEMA. FEMA developed
the model ordinance to provide NFIP communities with model language that could be adopted
as part of a community’s local land use and building regulatory codes to address the
requirements of the Bi-Op. FEMA requires each NFIP community to select one of the following
three approaches for implementation of the Bi- Op requirements, referred to as the “Three
Doors Approach”:
• Door #1: Adoption of the provisions of the FEMA model ordinance (programmatic
approach);
• Door #2: Checklist (community by community approach); and
• Door #3: Permit by Permit Compliance (project by project approach)
Page 13 of 117
In April 2010, the Auburn City Council adopted Ordinance No. 6295 which accepted the
Planning Commission’s recommendation to incorporate the provisions of the FEMA model
ordinance into the City’s Flood Hazard Area regulations (Chapter 15.68 ACC), and adopting a
revised Regulatory Floodplain Map. The ordinance also amended sections of City Code chapters
14.03, 16.10, 17.04, 17.09, 17.14, and 18.70.
The City’s amended Flood Hazard Area regulations were approved by FEMA on September 21,
2011, recognizing the City as a ‘Door 1’ community and providing the City with coverage under
the Endangered Species Act for its floodplain management activities.
In December 2013, FEMA issued an updated Model Ordinance for regulating floodplain
development. City staff has been waiting to update the code to coordinate with the updated
Federal Insurance Rate Maps (FIRM) that are being issued by FEMA. As anticipated FEMA
contacted the City of Auburn to update our FIRM references on February, 19th 2020 and have
until August 19th, 2020 to make the update. City staff has prepared updates to ACC, Chapter
15.68 to include the changes from the Model Ordinance to be consistent with City
standards/practices for Planning Commission’s consideration.
City staff routed the City’s updated ACC, Chapter 15.68 to FEMA and Department of Ecology’s
(DOE) NFIP State Coordinator, David Radabaugh at the end of 2019 for review and input to
ensure it meets current standards. Between March 3rd and March 30th additional comments
were provided by David Radabaugh. These additional comments from DOE were provided in
response to the Letter of Determination from FEMA directing City of Auburn to update our
floodplain code and adopt the new flood insurance studies that have been under review for the
past 13-years. David would have liked to have provided the comments sooner, however they
made the changes to FEMA’s model ordinance on December 2019 which was right in the
middle of the State Commerce review of the City’s Draft Floodplain code. The proposed
changes to the ACC, Chapter 15.68 are shown by strikeout/underline code attached to this
memo as Exhibit A. A clean version of the ACC, Chapter 15.68 is also provided per request at
the Planning Commission meeting that occurred on March 3rd, 2020.
STAFF PROPOSED UPDATES
Based on Staff’s implementation of the Floodplain Development Code over the years, the
Model Ordinance for the Puget Sound Region, and required changes from DOE, below are the
substantive changes to ACC, Chapter 15.68:
• Reorganize ACC, Chapter 15.68 to correspond to the layout of the latest FEMA Model
Ordinance for the Puget Sound Region. The changes that are transmitted under cover of
this memo look extensive because of the amount of strikethrough and underline, however
much of that is due to relocating existing adopted code language from one place to another.
In other words, underlined language may not be new and may instead reflect a change in
the organizational structure of the code. For this reason, staff is identifying this bulleted list
of substantive changes.
• Update the definitions section to have the latest definitions per NFIP, NMFS, FEMA, DOE
and City of Auburn. This comes from the latest Model Ordinance and current
correspondence with FEMA and DOE.
• Definition of area to be regulated for floodplain development (see further discussion below)
• Designation of the Channel Migration Area (see further discussion below)
Page 14 of 117
• Remove all of the permit application submittal criteria from ACC, Chapter 15.68 and include
it in the floodplain development permit application only. Per recent comments from DOE
some basic permit application submittal criteria is required in the code and has been added
since the last meeting.
• Information already provided in ACC 18.70.025 for variances is removed to avoid
redundancy.
• Establishing a minimum setback for structures of 15 feet from the ‘Protected Area’, or if not
met, a habitat assessment is required.
• Remove a date for assessing cumulative improvements.
• Increasing the requirements for what is to be addressed in Habitat Mitigation Plans
prepared for developments located outside of the Protected Area (Note: Does not change
the requirement of whether or not to prepare a Habitat Mitigation Plan).
• Update the Flood Insurance Study (FIS) and Flood Insurance Rate Map (FIRM) reference
dates to be August 19, 2020 for King County and March 7, 2017 for Pierce County Areas.
Please note that maps of the north end of the City of Auburn that show the existing and
proposed special flood hazard areas were e-mailed and mailed to the Planning Commission
members as requested at the Planning Commission meeting that occurred on March 3rd,
2020.
• Update the code per various comments received from DOE between March 2nd to March
30th. The details of all of the required changes are provided in a separate document called
Comments from Department of Ecology that was prepared by David Radabaugh, with DOE.
Below is a brief summary of the required changes.
o Additional updates to the exact working of some definitions
o Update the reference to the Flood Insurance Studies to be 8/19/2020
o A portion of the Urban Growth Area is in an area covered by the Pierce County FIS,
the City should also adopt the Pierce County FIS and FIRMs
o Basic floodplain permit application requirements are needed in code.
o A new section for Notification to Other Entities was added
o Building construction and documentation requirements were slightly updated
o Additional variance criteria was added
o A new section for Standard for Shallow Flooding Areas (AO Zones) was added
Key Ordinance Change No. 1 - Area to be Regulated
In the 2010 Model Ordinance used by the City for development of its current regulations, the
area specified to be regulated is the Special Flood Hazard Area (SFHA) and all ‘Protected Areas’.
The 2013 revised Model Ordinance specifies that the area to be regulated is the SFHA (inclusive
of any ‘Protected Areas’ that are located within the extent of the SFHA) and removes the
reference to “Protected Areas”.
Protected Areas include the Riparian Habitat Zone (RHZ), any mapped Channel Migration Area
(CMAs), and the FEMA-designated floodway. The RHZ is a dimensioned zone adjacent to rivers
and streams located within the SFHA, and varies in width from 150 feet to 250 on each side of
the river of stream’s Ordinary High Water Mark (OHWM). In a number of cases in Auburn, the
extent of the RHZ reaches beyond the SFHA that the river or stream is located within, resulting
in a regulated area that includes the SFHA and the additional area of the RHZ that occurs
outside of the SFHA in which that reach of river or stream is located within. One significant area
where this occurs is along the western shoreline of the Green River, where there are urban
Page 15 of 117
densities of existing single-family and multi-family residences. In a number of cases, these RHZ
areas outside of the SFHA are also located behind existing levees, or at elevations that are not
expected to experience flooding during the base flood (also referred to as the “100-year” or
“1% annual recurrence probability” flood).
While the primary purpose of regulating this RHZ area outside of the SFHA is to protect or
preserve critical floodplain habitat for federally-listed threatened and endangered species,
many of these areas have previously been heavily developed, and consist of structures, paved
or other impervious surfaces, and urban landscaping, and consequently offer little habitat value
to aquatic species.
Auburn also has a mapped CMA for the Green River that is presently included as part of its
regulatory floodplain as required by the original (2010) Model Ordinance. Similar to the RHZ,
the CMA also extends beyond the SFHA area in a number of areas within the City, and in many
cases portions of this area are also located behind existing levees.
The third element of the Protected Area, the FEMA-designated floodway, is in all cases located
within the FEMA-designated SFHA and therefore does result in any additional areas for
floodplain regulation beyond the SFHA under the City’s current regulations.
City staff recommends revising the regulatory floodplain to include the SFHA and the Protected
Area as it occurs within the SFHA, unless the area is undeveloped with predominately native
vegetation that have benefits to endangered species, in which case the regulations for riparian
habitat zones shall apply and be included in the regulatory floodplain. This so that existing built
out areas are not exposed to development requirements that don’t make sense when they are
expanding or modifying a development. The intent is to apply the critical area and floodplain
regulations to areas where it matters most and to not require habitat protection plans or other
types of efforts in already built out areas.
Key Ordinance Change No. 2 - Designation of Channel Migration Area
The 2010 Model Ordinance required CMAs to be delineated as part of the regulatory floodplain
map, in any areas where channel migration areas had previously been mapped and adopted for
local regulatory purposes, with the addition of 50 feet. It further specified that if there was no
adopted channel migration area map for a water body, that there was no requirement to
prepare a new delineation of a CMA for floodplain regulatory purposes.
The 2013 revised Model Ordinance specifies that where a channel migration area has not been
mapped/adopted by the community, that a floodplain permit applicant shall either designate
the entire SFHA as the channel migration area, or conduct a study to identify the channel
migration area in accordance with FEMA’s Regional Guidance for Hydrologic and Hydraulic
Studies. The revised Model Ordinance also specifies that the floodplain administrator shall use
the most restrictive data available for determining the channel migration area.
At the time of the City’s 2010 flood hazard area amendments, the only established mapped
channel migration area in Auburn was associated with the Green River (identified by a 1993
King County channel migration study). As a result, the only CMA that is designated on the City’s
current regulatory floodplain map is the Green River CMA. A channel migration area has not yet
Page 16 of 117
been mapped for the White River or Mill Creek, and there is therefore no CMA designated or
required to be evaluated for development applications in the SFHA for these water bodies.
The revised Model Ordinance requires that for any floodplain permit application for
development located within the SFHA where a CMA has not yet been mapped (White River
SFHIA, Mill Creek SFHA, and portions of Green River SFHA), the applicant has the option of
treating the entire SFHA within the project area as a CMA, or to submit a special
hydrologic/hydraulic study that establishes the location of the CMA pursuant to FEMA’s
technical criteria.
City staff recommends that we provide applicants for development within the floodplain the
option to either provide a study that locates the CMA for their proposed development site as
described in the revised Model Ordinance or designate that all areas in the SFHA for which no
CMA has been mapped shall meet the requirements for a CMA (i.e. all SFHAs without a mapped
CMA would be automatically included as part of the Protected Area).
Page 17 of 117
1
Comments From Department of Ecology
Draft Auburn Flood Damage Prevention Ordinance
Received March 18, 2020.
1. ACC 15.68.020 G and H have incomplete sentences and do not make sense.
2. The definition of Base Flood needs to be changed. “Base flood” means the flood having
a one percent chance of being equaled or exceeded in any given year (also referred to
as the “100-year flood”). Flooding can occur outside of the FEMA mapped SFHA.
3. Certain definitions need to be corrected:
a. Base Flood Elevation (BFE): The elevation to which floodwater is anticipated to
rise during the base flood.
b. Critical Facility. The draft has arguably created a circular definition. What is a
“critical public facility.” Please clarify.
c. Development: Any man-made change to improved or unimproved real estate,
including but not limited to buildings or other structures, mining, dredging,
filling, grading, paving, excavation or drilling operations or storage of equipment
or materials located within the area of special flood hazard.
d. Elevation Certificate: An administrative tool of the National Flood Insurance
Program (NFIP) that can be used to provide elevation information, to determine
the proper insurance premium rate, and to support a request for a Letter of Map
Amendment (LOMA) or Letter of Map Revision based on fill (LOMR-F).
e. Floodway: The channel of a river or other watercourse and the adjacent land
areas that must be reserved in order to discharge the base flood without
cumulatively increasing the water surface elevation more than a designated
height. Also referred to as "Regulatory Floodway."
f. Functionally dependent use: A use which cannot perform its intended purpose
unless it is located or carried out in close proximity to water. The term includes
only docking facilities, port facilities that are necessary for the loading and
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unloading of cargo or passengers, and ship building and ship repair facilities, and
does not include long-term storage or related manufacturing facilities.
g. Lowest Floor: 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 (i.e. provided there are adequate flood
ventilation openings).
h. Mean Sea Level: For purposes of the National Flood Insurance Program, the
vertical datum to which Base Flood Elevations shown on a community's Flood
Insurance Rate Map are referenced.
i. New construction: For the purposes of determining insurance rates, structures
for which the “start of construction” commenced on or after the effective date
of an initial Flood Insurance Rate Map or after December 31, 1974, whichever is
later, and includes any subsequent improvements to such structures. For
floodplain management purposes, “new construction” means structures for
which the "start of construction" commenced on or after the effective date of a
floodplain management regulation adopted by a community and includes any
subsequent improvements to such structures.
J. Recreational Vehicle: A vehicle,
1) Built on a single chassis;
2) 400 square feet or less when measured at the largest horizontal projection;
3) Designed to be self-propelled or permanently towable by a light duty truck;
and
4) Designed primarily not for use as a permanent dwelling but as temporary
living quarters for recreational, camping, travel, or seasonal use.
k. Start of construction: Includes substantial improvement and means the date the
building permit was issued, provided the actual start of construction, repair,
reconstruction, rehabilitation, addition, placement, or other improvement was
within 180 days from the date of the permit. The actual start means either the
first placement of permanent construction of a structure on a site, such as the
pouring of slab or footings, the installation of piles, the construction of columns,
or any work beyond the stage of excavation; or the placement of a
manufactured home on a foundation. Permanent construction does not include
land preparation, such as clearing, grading, and filling; nor does it include the
installation of streets and/or walkways; nor does it include excavation for a
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basement, footings, piers, or foundations or the erection of temporary forms;
nor does it include the installation on the property of accessory buildings, such
as garages or sheds not occupied as dwelling units or not part of the main
structure. For a substantial improvement, the actual start of construction means
the first alteration of any wall, ceiling, floor, or other structural part of a building,
whether or not that alteration affects the external dimensions of the building.
l. Substantial improvement: Any reconstruction, rehabilitation, addition, or other
improvement of a structure, the cost of which equals or exceeds 50 percent of
the market value of the structure before the "start of construction" of the
improvement. This term includes structures which have incurred "substantial
damage," regardless of the actual repair work performed. The term does not,
however, include either:
1) Any project for improvement of a structure to correct previously identified
existing violations of state or local health, sanitary, or safety code specifications
that have been identified by the local code enforcement official and that are the
minimum necessary to assure safe living conditions; or
2) Any alteration of a "historic structure," provided that the alteration will not
preclude the structure's continued designation as a "historic structure.”
4. Update the reference to the Flood Insurance Studies (FIS). Because a portion of the
UGA is in an area covered by the Pierce County FIS, the city should also adopt the Pierce
County FIS and FIRMs.
Basis for Establishing the Areas of Special Flood Hazard
The special flood hazard areas identified by the Federal Insurance Administrator in a
scientific and engineering report entitled “The Flood Insurance Study (FIS) for King
County Washington and Incorporated Areas” dated August 19, 2020, and any revisions
thereto, with accompanying Flood Insurance Rate Maps (FIRMs) dated August 19, 2020,
and any revisions thereto, as well as the special flood hazard areas identified by the
Federal Insurance Administrator in a scientific and engineering report entitled “The
Flood Insurance Study (FIS) for Pierce County Washington and Incorporated Areas”
dated March 7, 2017, and any revisions thereto, with accompanying Flood Insurance
Rate Maps (FIRMs) dated March 7, 2017, and any revisions thereto, are hereby adopted
by reference and declared to be a part of this ordinance. The FIS and the FIRM are on
file at 1 East Main St, Auburn, WA 98001.
5. Add basic application submittal requirements in code:
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15.68.170 Floodplain Development Permit Application.
Applications for a floodplain development permit shall be made using the criteria
outlined in the Floodplain Development Application Packet available for download at
www.auburnwa.gov/forms.
At a minimum, the following information is required:
1) Elevation in relation to mean sea level, of the lowest floor (including basement) of all
structures recorded on a current elevation certificate with Section B completed by
the Floodplain Administrator.
2) Elevation in relation to mean sea level to which any structure has been flood
proofed;
3) Where a structure is to be flood proofed, certification by a registered professional
engineer or architect that the flood proofing methods for any nonresidential
structure meet flood proofing criteria in Section 5.2-2;
4) Description of the extent to which a watercourse will be altered or relocated as a
result of proposed development;
5) Where development is proposed in a floodway, an engineering analysis indicating no
rise of the Base Flood Elevation; and
6) Any other such information that may be reasonably required by the Floodplain
Administrator in order to review the application.
6. Add to ACC 165.68.200:
Review all floodplain development permits to verify that proposed development will be
reasonably safe from flooding.
7. 15.68.XXX Notification to Other Entities – Add this new section
Whenever a watercourse is to be altered or relocated:
1) Notify adjacent communities and the Department of Ecology prior to such alteration
or relocation of a watercourse, and submit evidence of such notification to the
Federal Insurance Administrator through appropriate notification means, and
2) Assure that the flood carrying capacity of the altered or relocated portion of said
watercourse is maintained.
8. Modify 15.68.210 Records, to read:
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A. Where base flood elevation data have been obtained pursuant to Section 15.68.130
and 15.68.150, the floodplain administrator or designee shall obtain, record, and
maintain the actual “finished construction” elevations provided by the applicant for
the locations listed in Section 15.68.170. This information shall be recorded on a
current FEMA Elevation Certificate signed and sealed by a professional land
surveyor, currently licensed in the State of Washington.
B. For all new or substantially improved dry floodproofed nonresidential structures,
where base flood elevation data has been obtained pursuant to Section 15.68.130
and 15.68.150, the floodplain administrator or designee shall obtain, record and
maintain the elevation (in relation to the datum of the effective FIRM) to which the
structure was floodproofed. This information shall be recorded on a current FEMA
Floodproofing Certificate by a professional engineer currently licensed in the State
of Washington.
C. Certification required by Section 5.4.1 {or the numbering system used by the
community} (floodway encroachments).
D. Records of all variance actions, including justification for their issuance.
E. Improvement and damage calculations.
F. Maintain for public inspection all records pertaining to the provisions of this
ordinance.
9. Added variance criteria:
D. Variances shall only be issued:
a) Upon a determination that the granting of a variance will not result in increased
flood heights, additional threats to public safety, extraordinary public expense,
create nuisances, cause fraud on or victimization of the public, or conflict with
existing local laws or ordinances;
b) For the repair, rehabilitation, or restoration of historic structures upon a
determination that the proposed repair or rehabilitation will not preclude the
structure’s continued designation as a historic structure and the variance is the
minimum necessary to preserve the historic character and design of the structure;
d) Upon a determination that failure to grant the variance would result in exceptional
hardship to the applicant;
e) Upon a showing that the use cannot perform its intended purpose unless it is
located or carried out in close proximity to water. This includes only facilities defined
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in Section 2.0 {or the numbering system used by the community} of this ordinance
in the definition of “Functionally Dependent Use.”
E. Variances shall not be issued within any floodway if any increase in flood levels
during the base flood discharge would result.
F) Generally, variances may be issued for new construction and substantial
improvements to be erected on a lot of one-half acre or less in size contiguous to
and surrounded by lots with existing structures constructed below the BFE, provided
the procedures of Sections 4.0 and 5.0 {or the numbering system used by the
community} of this ordinance have been fully considered. As the lot size increases
beyond one-half acre, the technical justification required for issuing the variance
increases.
G. Variance Criteria
1) In considering variance applications, the {Governing Body} shall consider all
technical evaluations, all relevant factors, all standards specified in other
sections of this ordinance, 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;
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i) The safety of access to the property in time of flood for ordinary and
emergency vehicles;
j) The expected heights, velocity, duration, rate of rise, and sediment transport
of the floodwaters 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 system, and streets and bridges.
10. The following is also recommended:
Additional Requirements for the Issuance of a Variance
1) Any applicant to whom a variance is granted shall be given written notice over the
signature of a community official that:
a. The issuance of a variance to construct a structure below the BFE will result in
increased premium rates for flood insurance up to amounts as high as $25 for
$100 of insurance coverage, and
b. Such construction below the BFE increases risks to life and property.
2) The Floodplain Administrator shall maintain a record of all variance actions, including
justification for their issuance.
3) The Floodplain Administrator shall condition the variance as needed to ensure that the
requirements and criteria of this chapter are met.
Variances as interpreted in the NFIP are based on the general zoning law principle that they
pertain to a physical piece of property; they are not personal in nature and do not pertain to
the structure, its inhabitants, economic or financial circumstances. They primarily address
small lots in densely populated residential neighborhoods. As such, variances from flood
elevations should be quite rare.
11. Delete ACC 15.68.150(D). This section creates floodways without a technical
justification.
12. Additions to ACC 15.68.310:
A. All manufactured homes shall be anchored to prevent flotation, collapse, or lateral
movement, and shall be installed using methods and practices that minimize flood
damage. Anchoring methods may include, but are not limited to, use of over-the-top or
frame ties to ground anchors.
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B. All new construction and substantial improvements shall be constructed using methods
and practices that minimize flood damage.
13. New section:
Enclosed Area Below the Lowest Floor
If buildings or manufactured homes are constructed or substantially improved with fully
enclosed areas below the lowest floor, the areas shall be used solely for parking of vehicles,
building access, or storage.
14. Recognize that as drafted, ACC 15.68.410.B would require an engineering analysis in
unnumbered A Zones.
15. If utilizing exceptions to floodway prohibition, then utilize complete text:
1) Replacement of Farmhouses in Floodway
Repairs, reconstruction, replacement, or improvements to existing farmhouse
structures located in designated floodways and that are located on lands
designated as agricultural lands of long-term commercial significance under RCW
36.70A.170 may be permitted subject to the following:
a) The new farmhouse is a replacement for an existing farmhouse on the same
farm site;
b) There is no potential building site for a replacement farmhouse on the same
farm outside the designated floodway;
c) Repairs, reconstruction, or improvements to a farmhouse shall not increase
the total square footage of encroachment of the existing farmhouse;
d) A replacement farmhouse shall not exceed the total square footage of
encroachment of the farmhouse it is replacing;
e) A farmhouse being replaced shall be removed, in its entirety, including
foundation, from the floodway within ninety days after occupancy of a new
farmhouse;
f) For substantial improvements and replacement farmhouses, the elevation
of the lowest floor of the improvement and farmhouse respectively,
including basement, is a minimum of one foot higher than the BFE;
g) New and replacement water supply systems are designed to eliminate or
minimize infiltration of floodwaters into the system;
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h) New and replacement sanitary sewerage systems are designed and located
to eliminate or minimize infiltration of floodwater into the system and
discharge from the system into the floodwaters; and
i) All other utilities and connections to public utilities are designed,
constructed, and located to eliminate or minimize flood damage.
2. Substantially Damaged Residences in Floodway
a) For all substantially damaged residential structures, other than
farmhouses, located in a designated floodway, the Floodplain
Administrator may make a written request that the Department of Ecology
assess the risk of harm to life and property posed by the specific conditions
of the floodway. Based on analysis of depth, velocity, flood-related erosion,
channel migration, debris load potential, and flood warning capability, the
Department of Ecology may exercise best professional judgment in
recommending to the local permitting authority repair, replacement, or
relocation of a substantially damaged structure consistent with WAC 173-
158-076. The property owner shall be responsible for submitting to the
local government and the Department of Ecology any information
necessary to complete the assessment. Without a favorable
recommendation from the department for the repair or replacement of a
substantially damaged residential structure located in the regulatory
floodway, no repair or replacement is allowed per WAC 173-158-070(1).
b) Before the repair, replacement, or reconstruction is started, all
requirements of the NFIP, the state requirements adopted pursuant to
86.16 RCW, and all applicable local regulations must be satisfied. In
addition, the following conditions must be met:
i) There is no potential safe building location for the replacement
residential structure on the same property outside the regulatory
floodway.
ii) A replacement residential structure is a residential structure built as a
substitute for a legally existing residential structure of equivalent use
and size.
iii) Repairs, reconstruction, or replacement of a residential structure
shall not increase the total square footage of floodway
encroachment.
iv) The elevation of the lowest floor of the substantially damaged or
replacement residential structure is a minimum of one foot higher
than the BFE.
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v) New and replacement water supply systems are designed to
eliminate or minimize infiltration of floodwater into the system.
vi) New and replacement sanitary sewerage systems are designed and
located to eliminate or minimize infiltration of floodwater into the
system and discharge from the system into the floodwaters.
vii) All other utilities and connections to public utilities are designed,
constructed, and located to eliminate or minimize flood damage.
16. Include AO Zone language:
STANDARDS FOR SHALLOW FLOODING AREAS (AO ZONES)
Shallow flooding areas appear on FIRMs as AO Zones with depth designations. The base flood
depths in these zones range from 1 to 3 feet above ground where a clearly defined channel
does not exist, or where the path of flooding is unpredictable and where velocity flow may be
evident. Such flooding is usually characterized as sheet flow. In addition to other provisions in
this code, the following additional provisions also apply in AO Zones:
1. New construction and substantial improvements of residential structures and manufactured
homes within AO Zones shall have the lowest floor (including basement and mechanical
equipment) elevated above the highest adjacent grade to the structure, one foot or more
above* the depth number specified in feet on the community’s FIRM (at least two feet
above the highest adjacent grade to the structure if no depth number is specified).
2. New construction and substantial improvements of nonresidential structures within AO
zones shall either:
a. 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
b. 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 substantially
impermeable to the passage of water and with structural components having the
capability of resisting hydrostatic and hydrodynamic loads and effects of buoyancy. If this
method is used, compliance shall be certified by a registered professional engineer, or
architect as in section 5.2-2(3).
3. Require adequate drainage paths around structures on slopes to guide floodwaters around
and away from proposed structures.
4. Recreational vehicles placed on sites within AO Zones on the community’s FIRM either:
a. Be on the site for fewer than 180 consecutive days, or
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b. 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
c. Meet the requirements of subsections (1) and (3) above and the anchoring
requirements for manufactured homes (Section 5.1-1(2)).
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Chapter 15.68
FLOODPLAIN DEVELOPMENT MANAGEMENT
Sections:
Section 1. General
15.68.010 Statutory Authorization.
15.68.020 Purpose.
15.68.030 Lands to which this Ordinance Applies.
15.68.040 Approach.
15.68.050 Penalties for Non-Compliance.
15.68.060 Interpretation.
15.68.070 Abrogation and Greater Restrictions.
15.68.080 Warning and Disclaimer of Liability.
15.68.090 Severability.
Section 2. Definitions
15.68.100 Definitions.
Section 3. Regulatory Data
15.68.110 Area to be Regulated.
15.68.120 Special Flood Hazard Area.
15.68.130 Flood Hazard Data.
15.68.140 Protected Area.
15.68.150 New Regulatory Data.
Section 4. Administration
15.68.160 Establishment of Floodplain Development Permit.
15.68.170 Floodplain Development Permit Application.
15.68.180 Floodplain Development Permit Expiration.
15.68.190 Designation of the Floodplain Administrator.
15.68.200 Duties of the Floodplain Administrator.
15.68.210 Notification to Other Entities.
15.68.220 Records.
15.68.230 Certificate of Occupancy.
15.68.240 Appeals.
15.68.250 Variance Criteria.
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Section 5. General Development Standards
15.68.260 Subdivisions.
15.68.270 Site Design.
15.68.280 Hazardous Materials.
15.68.290 Critical Facilities.
Section 6. Standards for Protection of Structures
15.68.300 Applicability.
15.68.310 Flood Protection Standards.
15.68.320 Nonresidential Construction.
15.68.330 Manufactured Homes.
15.68.340 Recreation Vehicles.
15.68.350 Appurtenant Structures.
15.68.360 Utilities.
Section 7. Standards for Habitat Protection
15.68.370 Non-Development Activities.
15.68.380 Activities Allowed with a Floodplain Development Permit.
15.68.390 Other Activities.
15.68.400 Native Vegetation.
15.68.410 Floodway Standards.
15.68.420 Standards for Shallow Flooding Areas (AO Zones)
15.68.430 Compensatory Storage.
15.68.440 Habitat Impact Assessment.
15.68.450 Habitat Mitigation Plan.
15.68.460 Alteration of Watercourses.
Section 1. General
15.68.010 Statutory Authorization.
A. The Legislature of the State of Washington has delegated the responsibility to local governmental units
to adopt regulations designed to promote the public health, safety and general welfare of its citizenry.
Therefore, the City does ordain as follows:
B. Findings of Fact:
Areas of Auburn are subject to periodic inundation and channel migration which may result in loss of life and
property, health and safety hazards, disruption of commerce and governmental services, extraordinary public
expenditures for protection and relief from flooding and channel migration, and impairment of the tax base, all
of which adversely affect the public health, safety and general welfare.
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When floodplains and watersheds are developed without taking appropriate care and precautions, flood
heights, frequencies, and velocities increase, which may cause a greater threat to humans, damage to
property, destruction of natural floodplain functions, and adverse impacts to water quality and habitat.
Rivers, streams, lakes, estuarine and marine areas and their floodplains are major elements of healthy aquatic
and riparian areas and conveyance of flood waters. If watersheds, rivers, streams, lakes, estuaries, floodplains
and other systems are not viewed holistically as biological and geomorphologic units, it may lead to serious
degradation of habitat and increased flood hazards to people and human development.
Over the years, natural processes have evolved that manage flood waters and channel flows in the most
effective and efficient manner. Disruption of these processes through alterations to land cover, stream
channels, wetlands and other water bodies which may lead to increased flood hazards, loss of life and
property, threats to public health, and loss of habitat.
15.68.020 Purpose.
It is the purpose of this ordinance to promote the public health, safety, and general welfare and to minimize
public and private losses due to flood conditions in specific areas by provisions designed to manage
development in order to:
A. Protect human life, health and property from the dangers of flooding;
B. Minimize the need for publicly funded and hazardous rescue efforts to save those who are isolated by
floodwaters;
C. Minimize expenditure of public money for costly flood damage repair and flood control projects;
D. Minimize disruption of commerce, governmental services, and government infrastructure;
E. Minimize damage to public facilities and utilities such as water and gas mains, electric, telephone and
sewer lines, streets and bridges located in the floodplain.;
F. Minimize cost impacts to public facilities and utilities such as water and gas mains, electric, telephone
and sewer lines, streets and bridges located in the special flood hazard area.;
G. Maintain a stable tax base by providing for the sound use of and development of flood hazard areas so
as to minimize blight areas caused by flooding;
H. Encourage those who occupy flood hazard areas be educated about the risks and challenges
associated with these areas.;
I. Qualify the City of Auburn for participation in the National Flood Insurance Program, thereby giving
citizens and businesses the opportunity to purchase flood insurance;
J. Maintain the quality of water in rivers, streams, and lakes, and their floodplains so as to protect public
water supplies, areas of the Public Trust, and wildlife habitat protected by the Endangered Species Act;
K. Retain the natural channel, shoreline, and floodplain creation processes and other natural floodplain
functions that protect, create, and maintain habitat for threatened and endangered species; and
L. Prevent or minimize loss of hydraulic, geomorphic, and ecological functions of floodplains and stream
channels.
15.68.030 Lands to which this Ordinance Applies.
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This ordinance shall apply to the Special Flood Hazard Area (SFHA) and associated protected areas within the
jurisdiction of the City of Auburn as defined in Section 3 of this Ordinance.
15.68.040 Approach.
In order to achieve the listed purposes, this ordinance:
A. Defines and clarifies the terms and phrases used in this ordinance in Section 2.
B. Identifies in Section 3 the Special Flood Hazard Area, the Protected Area and the supporting technical
data needed to delineate those areas.
C. Establishes a permit requirement in Section 4 so that all proposed development that may affect flood
hazards, water quality and habitat is reviewed prior to construction.
D. Sets minimum protection standards in Section 5 for all development to ensure that the development
will not increase the potential for flood damage or adversely affect natural floodplain functions.
E. Sets minimum protection standards to protect new and substantially improved structures from flood
damage in Section 6.
F. Specifies additional habitat protection criteria in Section 7. Some small projects do not need a
floodplain development permit (see ACC 15.68.380). For all other development projects, the applicant must
assess their impact on those factors that contribute to increased flood hazard and degradation of habitat. If the
assessment concludes that the project will cause an adverse effect outside the Protected Area, the permit will
be denied, unless the project impacts are mitigated (avoided, minimized, restored or compensated for).
15.68.050 Penalties for Noncompliance.
No development shall be undertaken or placed in the areas regulated by this ordinance without full compliance
with the terms of this ordinance and other applicable regulations of the City. 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 be enforced pursuant to the provisions of Chapter 1.25 ACC.
15.68.060 Interpretation.
In the interpretation and application of this ordinance, all provisions shall be:
A. Considered as minimum requirements;
B. Liberally construed in favor of the City; and,
C. Deemed neither to limit nor repeal any other powers granted under state statutes;
15.68.070 Abrogation and Regulation Conflicts
Where this ordinance and another code, or ordinance, conflict or overlap, whichever imposes the more
stringent restrictions shall prevail.
15.68.080 Warning and Disclaimer of Liability.
The degree of property and habitat protection required by this ordinance is considered reasonable for
regulatory purposes and is based on scientific and engineering considerations. Larger floods and movement of
channels outside of mapped channel migration areas may occur on rare occasions. Flood heights may be
increased by unnatural or natural causes. This ordinance does not imply that land outside the regulated areas
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or development permitted within such areas will be free from flood or erosion damage. This ordinance shall not
create liability on the part of the City, any officer or employee thereof, for any damage to property or habitat that
results from reliance on this ordinance or any administrative decision lawfully made hereunder.
15.68.090 Severability
The provisions and sections of this ordinance shall be deemed separable and the invalidity of any portion of
this ordinance shall not affect the validity of the remainder.
Section 2. Definitions
15.68.100 Definitions.
Unless specifically defined below, terms 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. “Adversely affect/adverse effect” means effects that are a direct or indirect result of the proposed
action or its interrelated or interdependent actions and the effect is not discountable, insignificant, or beneficial.
Discountable effects are extremely unlikely to occur. Insignificant effects relate to the size of the impact and
should never reach the scale where a take occurs. Based on best judgment, a person would not: 1) be able to
meaningfully measure, detect, or evaluate insignificant effects, or 2) expect discountable effects to occur.
Beneficial effects are contemporaneous positive effects without any adverse effects. In the event that the
overall effect of the proposed action is beneficial, but is also likely to cause some adverse effects, then the
proposed action is considered to result in an adverse effect.
B. “Alteration of watercourse” means any action that will change the location of the channel occupied by
water within the banks of any portion of a riverine waterbody.
C. “Appurtenant Structure” means a structure which is on the same parcel as the principle structure to be
insured and the use of which is incidental to the use of the principal structure.
D. “Area of shallow flooding” means a designated zone AO, AH, AR/AO or AR/AH (or VO) on a
community’s Flood Insurance Rate Map (FIRM) with a one percent or greater annual chance of flooding to an
average depth of one to three feet where a clearly defined channel does not exist, where the path of flooding is
unpredictable, and where velocity flow may be evident. Such flooding is characterized by ponding or sheet flow.
Also referred to as the sheet flow area.
E. “Area of special flood hazard” means the land in the floodplain within a community subject to a 1
percent or greater chance of flooding in any given year. It is shown on the Flood Insurance Rate Map (FIRM)
as zone A, AO, AH, A1-30, AE, A99, AR (V, VO, V1-30, VE). “Special flood hazard area” is synonymous in
meaning with the phrase “area of special flood hazard”.
F. “ASCE 24” means the most recently published version of ASCE 24, Flood Resistant Design and
Construction, published by the American Society of Civil Engineers.
G. “Base flood” means the flood having a one percent chance of being equaled or exceeded in any given
year (also referred to as the “100-year flood”).
H. “Base flood elevation” means the elevation to which floodwater is anticipated to rise during the base
flood.
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I. “Basement” means any area of the structure having its floor subgrade (below ground level) on all
sides.
J. “Building Code” means the currently effective versions of the International Building Code and the
International Residential Code adopted by the Washington State Legislature and any further amendments
adopted by the City of Auburn.
K. “Channel Migration Zone” (CMZ) means the area within the lateral extent of likely stream channel
movement due to stream bank destabilization and erosion, rapid stream incision, aggradation, avulsions, and
shifts in location of stream channels.
1. The channel migration area shall be the total area occupied by the river channel, the severe
channel migration hazard area, and the moderate channel migration hazard area as delineated in the
Green River Channel Migration Study published by King County dated December 1993 plus 50 feet.
2. The channel migration area shall be the total area occupied by the river channel, the severe
channel migration hazard area, and the moderate channel migration hazard area as delineated in the
Channel Migration Zone Delineation for the Middle Green River, RM 31.10 to 33.25 dated December
28, 2018 plus 50-feet which supersedes the study referenced above.
3. A site specific channel migration delineation may also be performed per the Washington State
Department of Ecology’s current requirements with recommended setbacks (A Framework for
Delineating Channel Migration Zones) prepared by a qualified engineer. The delineation shall be
prepared by a qualified consultant as that term is defined in these regulations. The city may retain a
qualified consultant paid for by the applicant to review and confirm the applicant’s reports, studies and
plans if the following circumstances exist:
a. The city has technical information that is unavailable to the applicant; or
b. The applicant has provided inaccurate or incomplete information on previous
proposals or proposals currently under consideration.
L. “Critical facility” means a facility necessary to protect the public health, safety and welfare during a
flood. Critical facilities include, but are not limited to, schools, nursing homes, hospitals, police, fire and
emergency operations installations, water and wastewater treatment plants, electric power stations, and
installations which produce, use, or store hazardous materials or hazardous waste (other than consumer
products containing hazardous substances or hazardous waste intended for household use).
M. “Development” means any human-made change to improved or unimproved real estate including but
not limited to buildings or other structures, mining, dredging, filling, grading, paving, excavation or drilling
operations or storage of equipment or materials located within the area of special flood hazard.
N. “Dry floodproofing” means any combination of structural and nonstructural measures that prevent flood
waters from entering a structure.
O. “Elevation Certificate” means an administrative tool of the National Flood Insurance Program (NFIP)
that can be used to provide elevation information, to determine the proper insurance premium rate, and to
support a request for a Letter of Map Amendment (LOMA) or Letter of Map Revision based on fill (LOMR-F).
P. “Essential Facility” has the same meaning as “Essential Facility” defined in ASCE 24. Table 1-1 in
ASCE 24-14 further identifies building occupancies that are essential facilities.
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Q. “FEMA” means the Federal Emergency Management Agency, the agency responsible for
administering the National Flood Insurance Program.
R. “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.
3. Mudslides (i.e., mudflows) which are proximately caused by flooding as defined in paragraph
(2) of this definition and are akin to a river of liquid and flowing mud on the surfaces of normally dry
land areas, as when earth is carried by a current of water and deposited along the path of the current.
4. The collapse or subsidence of land along the shore of a lake or other body of water as a result
of erosion or undermining caused by waves or currents of water exceeding anticipated cyclical levels
or suddenly caused by an unusually high water level in a natural body of water, accompanied by a
severe storm, or by an unanticipated force of nature, such as flash flood or an abnormal tidal surge, or
by some similarly unusual and unforeseeable event which results in flooding as defined in paragraph
(1) of this definition.
S. “Flood elevation study” means an examination, evaluation and determination of flood hazards and, if
appropriate, corresponding water surface elevations, or an examination, evaluation and determination of
mudslide (i.e., mudflow) and/or flood-related erosion hazards. Also known as a Flood Insurance Study (FIS).
T. “Flood insurance rate map (FIRM)” means the official map on which the Federal Emergency
Management Agency has delineated both the Special Flood Hazard Areas and the risk premium zones
applicable to the community.
U. “Flood insurance study (FIS)” means the official report(s) provided by the Federal Emergency
Management Agency that includes flood profiles, the flood insurance rate map, and the water surface elevation
of the base flood.
V. “Floodplain or flood prone area” means any land area susceptible to being inundated by water from
any source. See "Flood or flooding."
W. “Floodplain administrator” means the community official designated by title to administer and enforce
the floodplain management regulations.
X. “Flood proofing” means any combination of structural and nonstructural additions, changes, or
adjustments to structures which reduce or eliminate risk of flood damage to real estate or improved real
property, water and sanitary facilities, structures, and their contents. Flood proofed structures are those that
have the structural integrity and design to be impervious to floodwater below the Base Flood Elevation.
Y. “Flood protection elevation (FPE)” means the elevation above the datum of the effective FIRM to which
new and substantially improved structures must be protected from flood damage.
Z. “Floodway” means the channel of a river or other watercourse and the adjacent land areas that must
be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation
more than a designated height. Also referred to the “Regulatory Floodway.
AA. “Functionally Dependent Use” means a use which cannot perform its intended purpose unless it is
located or carried out in close proximity to water. The term includes only docking facilities, port facilities that are
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necessary for the loading and unloading of cargo or passengers, and ship building and ship repair facilities, and
does not include long-term storage or related manufacturing facilities.
BB. “Highest adjacent grade” means the highest natural elevation of the ground surface prior to
construction next to the proposed walls of a structure.
CC. “Historic structure” means any structure that is:
1. Listed individually in the National Register of Historic Places (a listing maintained by the
Department of Interior) or preliminarily determined by the Secretary of the Interior as meeting the
requirements for individual listing on the National Register;
2. Certified or preliminarily determined by the Secretary of the Interior as contributing to the
historical significance of a registered historic district or a district preliminarily determined by the
Secretary to qualify as a registered historic district;
3. Individually listed on a state inventory of historic places in states with historic preservation
programs which have been approved by the Secretary of Interior; or
4. Individually listed on a local inventory of historic places in communities with historic
preservation programs that have been certified either:
a. By an approved state program as determined by the Secretary of the Interior, or
b. Directly by the Secretary of the Interior in states without approved programs.
DD. “Hyporheic zone” means a saturated layer of rock or sediment beneath and/or adjacent to a stream
channel that contains some proportion of channel water or that has been altered by channel water infiltration.
EE. “Impervious surface” means a non-vegetated surface area which either prevents or retards the entry of
water into the soil mantle as under natural conditions prior to development. A non-vegetated surface area
which causes water to run off the surface in greater quantities or at an increased rate of flow from the flow
present under natural conditions prior to development. Common impervious surfaces include, but are not
limited to, roof tops, walkways, patios, driveways, parking lots or storage areas, concrete or asphalt paving,
gravel roads, packed earthen materials, and oiled, macadam or other surfaces which similarly impede the
natural infiltration of stormwater.
FF. “Lowest floor” means 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 in ACC
15.68.170(A)(7) (i.e. provided there are adequate flood ventilation openings).
GG. “Manufactured home” means a structure, transportable in one or more sections, which is built on a
permanent chassis and is designed for use with or without a permanent foundation when attached to the
required utilities. The term “manufactured home” does not include a “recreational vehicle.”
HH. “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.
II. “Market value” shall mean the current assessed value as established by the most recent tax roll of the
county assessor in which the property is located. An applicant may, at applicant’s expense, provide an
appraisal to determine market value.
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JJ. “Mean Sea Level” means for purposes of the National Flood Insurance Program, the vertical datum to
which Base Flood Elevations shown on a community's Flood Insurance Rate Map are referenced.
KK. “Native vegetation” means plant species that are indigenous to the community’s area and that
reasonably could be expected to naturally occur on the site.
LL. “Natural floodplain functions” means the contribution that a floodplain makes to support habitat,
including, but not limited to, providing flood storage and conveyance, reducing flood velocities, reducing
sedimentation, filtering nutrients and impurities from runoff, processing organic wastes, moderating
temperature fluctuations, and providing breeding and feeding grounds, shelter, and refugia, for aquatic or
riparian species.
MM. “New construction” means for the purposes of determining insurance rates, structures for which the
“start of construction” commenced on or after the effective date of an initial Flood Insurance Rate Map or after
December 31, 1974, whichever is later, and includes any subsequent improvements to such structures. For
floodplain management purposes, “new construction” means structures for which the “start of construction”
commenced on or after the effective date of the ordinance adopted by a community and includes any
subsequent improvements to such structures.
NN. “Principal Structure” means a structure in which the principal use of the lot on which it is located is
conducted.
OO. “Protected area” means the lands that lie within the boundaries of the floodway, the riparian buffer
zone, and the channel migration area. Because of the impact that development can have on flood heights and
velocities and habitat, special rules apply in the Protected Area.
PP. “Reasonably Safe from Flooding” means development that is designed and built to be safe from
flooding based on consideration of current flood elevation studies, historical data, high water marks and other
reliable data known to the community. In unnumbered A zones where flood elevation information is not
available and cannot be obtained by practicable means, reasonably safe from flooding means that the lowest
floor is at least two feet above the Highest Adjacent Grade.
QQ. “Recreational vehicle” means a vehicle:
1. Built on a single chassis; and,
2. Four hundred square feet or less when measured at the largest horizontal projection; and,
3. Designed to be self-propelled or permanently towable by an automobile or light-duty truck;
and,
4. Designed primarily not for use as a permanent dwelling but as temporary living quarters for
recreational, camping, travel or seasonal use.
RR. “Riparian” means of, adjacent to, or living on, the bank of a stream, lake, pond, sound, or other water
body.
SS. “Riparian buffer zone” means the land located adjacent to streams, and other bodies of water, where
the natural soil, hydrology, and native flora and fauna perform important ecological functions such as protecting
the water body by filtering out pollutants, preventing erosion and sedimentation, stabilizing stream banks, and
providing natural shade. They are often thin lines-of-green containing native grasses, flowers, shrubs and trees
that line the banks of streams and other bodies of water. The riparian buffer zone for the Puget Sound
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Biological Opinion applies only to areas mapped within the Special Flood Hazard Area, unless the area is
undeveloped with predominately native vegetation that have benefits to endangered species, in which case the
regulations for riparian habitat zones shall apply.
TT. ”Riparian Habitat Zone” means the water body and adjacent land areas that are likely to support
aquatic and riparian habitat.
UU. “Special flood hazard area (SFHA)” means the land subject to inundation by the base flood. Special
flood hazard areas are designated on Flood Insurance Rate Maps with the letters “A” or “V” include AE
(floodway), AO, AH, A1-99 and VE. The Special Flood Hazard Area is also referred to as the area of special
flood hazard or SFHA.
VV. “Start of construction” includes substantial improvement, and means the date the building permit was
issued, provided the actual start of construction, repair, reconstruction, rehabilitation, addition, placement or
other improvement was within 180 days of the date of the permit. The actual start means either the first
placement of permanent construction of a structure on a site, such as the pouring of slab or footings, the
installation of piles, the construction of columns, or any work beyond the stage of excavation; or the placement
of a manufactured home on a foundation. Permanent construction does not include land preparation, such as
clearing, grading and filling; nor does it include the installation of streets and/or walkways; nor does it include
excavation for a basement, footings, piers, or foundations or the erection of temporary forms; nor does it
include the installation on the property of accessory buildings, such as garages or sheds not occupied as
dwelling units or not part of the main structure. For a substantial improvement, the actual “start of construction”
means the first alteration of any wall, ceiling, floor, or other structural part of a building, whether or not that
alteration affects the external dimensions of the building.
WW. “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.
XX. “Substantial damage” means damage of any origin sustained by a structure whereby the cost of
restoring the structure to its before-damaged condition would equal or exceed 50 percent of the market value of
the structure before the damage occurred
YY. “Substantial improvement” means any reconstruction, rehabilitation, addition, replacement or
improvement of a structure, the cost of which equals or exceeds 50 percent of the market value of the structure
before the “start of construction” of the improvement. This term includes structures which have incurred
"substantial damage," regardless of the actual repair work performed.
The term does not, however, include either:
1. Any project for improvement of a structure to correct existing violations of state or local health,
sanitary, or safety code specifications that have been identified by the local code enforcement official
and that are the minimum necessary to assure safe living conditions; or
2. Any alteration of a “historic structure” provided that the alteration will not preclude the
structure’s continued designation as a “historic structure”.
ZZ. “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.
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AAA. “Violation” means the failure of a structure or other development to be constructed or implemented in
conformance with the community’s applicable floodplain development regulations.
BBB. “Water typing” means a system for classifying water bodies according to their size and fish habitat
characteristics. The Washington Department of Natural Resources Forest Practices Water Typing
Classification System is hereby adopted by reference. The system defines four water types:
1. Type “S” – Shoreline: Streams that are designated “shorelines of the state,” including marine
shorelines.
2. Type “F” – Fish: Streams that are known to be used by fish or meet the physical criteria to be
potentially used by fish.
3. Type “Np” – Non-fish perennial streams.
4. Type “Ns” – Non-fish seasonal streams.
CCC. “Zone” means one or more areas delineated on the FIRM. The following zones may be used on the
adopted FIRM. The special flood hazard area is comprised of the A and V Zones.
1. A: SFHA where no base flood elevation is provided.
2. A#: Numbered A zones (e.g., A7 or A14), SFHA with a base flood elevation.
3. AE: SFHA with a base flood elevation.
4. AO: SFHA subject to inundation by shallow flooding usually resulting from sheet flow on
sloping terrain, with average depths between one and three feet. Average flood depths are shown.
5. AH: SFHA subject to inundation by shallow flooding (usually areas of ponding) with average
depths between one and three feet. Base flood elevations are shown.
6. B: The area between the SFHA and the 500-year flood of the primary source of flooding. It
may also be an area with a local, shallow flooding problem or an area protected by a levee.
7. C: An area of minimal flood hazard, as above the 500-year flood level of the primary source of
flooding. B and C zones may have flooding that does not meet the criteria to be mapped as a special
flood hazard area, especially ponding and local drainage problems.
8. D: Area of undetermined but possible flood hazard.
9. X: The area outside the mapped SFHA.
10. Shaded X: The same as a Zone B, above.
Section 3. Regulatory Data
15.68.110 Area to be Regulated.
The area to be regulated is comprised of the Special Flood Hazard Area and all Protected Areas within the
Special Flood Hazard Area within the jurisdiction of the City of Auburn. The term also includes areas delineated
pursuant to Section 15.68.150.
15.68.120 Special Flood Hazard Area.
Basis for Establishing the Areas of Special Flood Hazard
A. The special flood hazard areas identified by the Federal Insurance Administrator in a scientific and
engineering report entitled “The Flood Insurance Study (FIS) for King County Washington and Incorporated
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Areas” dated August 19, 2020, and any revisions thereto, with accompanying Flood Insurance Rate Maps
(FIRMs) dated August 19, 2020, and any revisions thereto, as well as the special flood hazard areas identified
by the Federal Insurance Administrator in a scientific and engineering report entitled “The Flood Insurance
Study (FIS) for Pierce County Washington and Incorporated Areas” dated March 7, 2017, and any revisions
thereto, with accompanying Flood Insurance Rate Maps (FIRMs) dated March 7, 2017, and any revisions
thereto, are hereby adopted by reference and declared to be a part of this ordinance. The FIS and the FIRM
are on file at 1 East Main St, Auburn, WA 98001.
B. The best available information for flood hazard area identification as outlined in Section 15.68.130(D)
shall be the basis for regulation until a new FIRM is issued that incorporates data utilized under Section
15.68.130(D).
C. Upon receipt of a floodplain development permit application, the floodplain administrator or designee
shall compare the elevation of the site to the base flood elevation.
D. The floodplain administrator or designee shall inform the applicant that the project may still be subject
to the flood insurance purchase requirements unless the owner receives a Letter of Map Amendment (LOMA)
from FEMA.
E. The floodplain administrator or designee shall make interpretations where needed, as to the exact
locations of the boundaries of the SFHA and the Protected Area (e.g. where there appears to be a conflict
between the mapped SFHA boundary and actual field conditions as determined by the base flood elevation and
ground elevations) as it applies to proposed development. The applicant may appeal the floodplain
administrator’s or designee’s interpretation of the location of the boundary to the Hearing Examiner for the City
of Auburn.
15.68.130 Flood Hazard Data.
A. The base flood elevation for the SFHAs incorporated in 15.68.120(A) shall be utilized.
B. The Flood Protection Elevation (FPE) shall be the base flood elevation plus one (1) foot.
C. The floodway shall be as delineated on the Flood Insurance Rate Map.
D. Where base flood elevation and floodway data have not been provided in Special Flood Hazard Areas,
the floodplain administrator or designee shall obtain, review and reasonably utilize any base flood elevation and
floodway data available from a Federal, State or other source.
15.68.140 Protected Area.
A. The Protected Area is comprised of those lands that lie within the boundaries of the floodway, the
riparian buffer zone, and the channel migration area.
B. In riverine areas, where a floodway has been designated in accordance with Sections 15.68.130(C),
15.68.130(D) or 15.68.150(E), the Protected Area is comprised of those lands that lie within the boundaries of
the riparian buffer zone, the channel migration area, and the SFHA.
C. Riparian Buffer Zone: The riparian buffer zone includes those watercourses within the SFHA and
adjacent land areas that are likely to support aquatic and riparian habitat.
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1. The size and location of the riparian buffer zone is dependent on the type of water body. The
riparian buffer zone includes the water body and adjacent lands, measured perpendicularly from
ordinary high water mark on both sides of the water body:
a. Type S streams that are designated “shorelines of the State:” 250 feet
b. Type F streams (fish bearing) streams greater than 5 feet wide and marine
shorelines: 200 feet
c. Type F streams less than 5 feet wide and lakes: 150 feet
d. Type N (nonsalmonid-bearing) perennial and seasonal streams with unstable slopes:
225 feet
e. All other Type N (nonsalmonid-bearing) perennial and seasonal streams: 150 feet.
2. The riparian buffer zone shall be delineated on the site plan by the applicant at the time of
application for subdivision approval or floodplain development permit for all development proposals
within 300 feet of any stream or shoreline.
D. Channel Migration Area:
a. The channel migration area shall be the channel migration zone as defined in Section
15.68.100(K).
b. Where more than one channel migration zone has been delineated, the floodplain
administrator or designee shall use the delineation that has been adopted for other local
regulatory purposes.
c. Where a channel migration zone has not yet been mapped, the provisions of Section
15.68.150(D) shall apply at the time of permit application.
15.68.150 New Regulatory Data.
A. All requests to revise or change the flood hazard data, including requests for a Letter of Map Revision
and a Conditional Letter of Map Revision shall be reviewed by the floodplain administrator or designee.
1. The floodplain administrator or designee shall not sign the Community Acknowledgment Form
for any requests based on filling or other development, unless the applicant for the letter documents
that such filling or development is in compliance with this ordinance.
2. The floodplain administrator or designee shall not approve a request to revise or change a
floodway delineation until FEMA has issued a Conditional Letter of Map Revision that approves the
change.
B. If an applicant disagrees with the regulatory data prescribed by this ordinance, he/she may submit a
detailed technical study needed to replace existing data with better data in accordance with FEMA mapping
guidelines or Regional Guidance for Hydrologic and Hydraulic Studies in Support of the Model Ordinance for
Floodplain Management under the National Flood Insurance Program and Endangered Species Act FEMA
Region X, 2010. If the data in question are shown on the published FIRM, the submittal must also include a
request to FEMA for a Conditional Letter of Map Revision.
C. Where base flood elevation data are not available in accordance with Section 15.68.130, applicants for
approval of new subdivisions and other proposed developments (including proposals for manufactured home
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parks) greater than 50 lots or 5 acres, whichever is the lesser, shall include such data with their permit
applications.
D. Where channel migration zone data are not available in accordance with 15.68.140(D), the permit
applicant shall either:
1. Designate the entire SFHA as the channel migration zone or
2. Identify the channel migration area in accordance with Regional Guidance for Hydrologic and
Hydraulic Studies in Support of the Model Ordinance for Floodplain Management under the National
Flood Insurance Program and Endangered Species Act FEMA Region X, 2012.
E. All new hydrologic and hydraulic flood studies conducted pursuant to Section 15.68.150 shall be in
accordance with Regional Guidance for Hydrologic and Hydraulic Studies in Support of the Model Ordinance
for Floodplain Management under the National Flood Insurance Program and the Endangered Species Act,
FEMA, Region X, 2010.
F. The floodplain administrator shall use the most restrictive data available prepared specifically for the
project site for the channel migration zone, floodways, future conditions, and riparian buffer zone.
Section 4. Administration
15.68.160 Establishment of Floodplain Development Permit
A floodplain development permit shall be obtained before construction or development begins within the
Special Flood Hazard Area (SFHA) or Protected Area. The permit shall be for all development as set forth in
15.68.170 Floodplain Development Permit Application.
Applications for a floodplain development permit shall be made using the criteria outlined in the Floodplain
Development Application Packet available for download at www.auburnwa.gov/forms. At a minimum, the
following information is required.
A. Elevation in relation to mean sea level, of the lowest floor (including basement) of all structures
recorded on a current elevation certificate with Section B completed by the Floodplain Administrator.
B. Elevation in relation to mean sea level to which any structure has been flood proofed;
C. Where a structure is to be flood proofed, certification by a registered professional engineer or architect
that the flood proofing methods for any nonresidential structure meet flood proofing criteria in Section 5;
D. Description of the extent to which a watercourse will be altered or relocated as a result of proposed
development;
E. Where development is proposed in a floodway, an engineering analysis indicating no rise of the Base
Flood Elevation; and
F. Any other such information that may be reasonably required by the Floodplain Administrator in order to
review the application.
15.68.180 Floodplain Development Permit Expiration.
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If there has been no start of construction, a floodplain development permit shall expire 180 days after the date
of issuance. Where the applicant documents a need for an extension beyond this period due to conditions
beyond the applicant’s control, the floodplain administrator or designee may authorize one or more extensions.
15.68.190 Designation of the Floodplain Administrator.
The Director of Community Development is hereby appointed to administer, interpret, and implement this
ordinance by granting or denying floodplain development permit applications in accordance with its provision.
The Director of Community Development may designate administration of portions or all of this ordinance to a
qualified person.
15.68.200 Duties of the Floodplain Administrator.
Duties of the floodplain administrator or designee shall include, but are not limited to:
A. Review all floodplain development permits to determine that the permit requirements of this ordinance
have been satisfied.
B. Review all floodplain development permits to determine that all necessary permits have been obtained
from those Federal, State or local government agencies from which prior approval is required, including those
local, State or Federal permits that may be required to assure compliance with the Endangered Species Act
and/or other appropriate State or Federal laws.
C. Review all floodplain development permits to determine if the proposed development is located in the
Protected Area. If located in the Protected Area, ensure that the provisions of Section 7 are met.
D. Ensure that all development activities within the Special Flood Hazard Area of the jurisdiction of the
City meet the requirements of the ordinance.
E. Inspect all development projects before, during and after construction to ensure compliance with all
provisions of this ordinance, including proper elevation of the structure.
F. Maintain for public inspection all records pertaining to the provisions of this ordinance.
G. Submit reports to include the projects for which they issue floodplain development permits, including
effects to flood storage, fish habitat, and all indirect effects of development and mitigation provided to FEMA as
required by the National Flood Insurance Program.
H. Notify FEMA of any proposed amendments to this ordinance and when annexations occur in the
Special Flood Hazard Area.
I. Ensure the proposed development is not located in the floodway. If located in the floodway, assure the
encroachment provisions of Section 15.68.410 are met
J. Cooperate with State and Federal agencies to improve flood and other technical data and notify FEMA
of any new data that would revise the FIRM.
K. Review all floodplain development permits to verify that proposed development will be reasonably safe
from flooding.
15.68.210 Notification to Other Entities
Whenever a watercourse is to be altered or relocated:
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A. Notify adjacent communities and the Department of Ecology prior to such alteration or relocation of a
watercourse, and submit evidence of such notification to the Federal Insurance Administrator through
appropriate notification means, and
B. Assure that the flood carrying capacity of the altered or relocated portion of said watercourse is
maintained.
15.68.220 Records.
A. Where base flood elevation data have been obtained pursuant to Section 15.68.130 and 15.68.150,
the floodplain administrator or designee shall obtain, record, and maintain the actual “finished construction”
elevations provided by the applicant for the locations listed in Section 15.68.170. This information shall be
recorded on a current FEMA Elevation Certificate signed and sealed by a professional land surveyor, currently
licensed in the State of Washington.
B. For all new or substantially improved dry floodproofed nonresidential structures, where base flood
elevation data has been obtained pursuant to Section 15.68.130 and 15.68.150, the floodplain administrator or
designee shall obtain, record and maintain the elevation (in relation to the datum of the effective FIRM) to
which the structure was floodproofed. This information shall be recorded on a current FEMA Floodproofing
Certificate by a professional engineer currently licensed in the State of Washington.
C. Certification required by Section 15.68.410 (floodway encroachments).
D. Records of all variance actions, including justification for their issuance.
E. Improvement and damage calculations.
F. Maintain for public inspection all records pertaining to the provisions of this ordinance.
15.68.230 Certificate of Occupancy.
A. A final grading and/or storm permit for the property, physical completion for City of Auburn Capital
Improvement projects without a building, a certificate of occupancy (commercial building) or final building
inspection (residential structure) for a new or substantially improved structure or an addition shall not be issued
until:
1. The permit applicant provides a properly completed, signed and sealed Elevation or
Floodproofing Certificate showing finished construction data as required by Section 15.68.220;
2. If a mitigation plan is required by Sections 15.68.440 and 15.68.450, all work identified in the
plan has been completed according to the plan’s schedule;
3. The applicant provides copies of all required Federal, State, and local permits noted in the
permit application per Section 15.68.170;
4. All other provisions of this ordinance and conditions placed on the floodplain development
permit approval letter have been met.
15.68.240 Appeals.
A. The Hearing Examiner, as established by Chapter 2.46 of the Auburn City Code, shall hear and decide
appeals and requests for variances from the requirements of this ordinance.
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B. The Hearing Examiner shall hear and decide appeals when it is alleged there is an error in any
requirement, decision, or determination made by the floodplain administrator or designee in the enforcement or
administration of this ordinance.
C. Those aggrieved by the decision of the Hearing Examiner may appeal the decision to the superior
court of the county in which the project is located pursuant to Section 2.46.160 of the Auburn City Code.
D. Upon consideration of the factors of Section 15.68.250 and the purposes of this ordinance, the
Hearing Examiner may attach such conditions to the granting of the variance as he/she deems necessary to
further the purposes of this ordinance.
E. The floodplain administrator or designee shall maintain the records of all appeal actions and report any
variances to the Federal Emergency Management Agency upon request.
15.68.250 Variance Criteria.
A. In addition to the Criteria outlined in ACC 18.70.025, in reviewing applications for a variance, the
Hearing Examiner shall consider all technical evaluations, all relevant factors, standards specified in other
sections of this ordinance; and:
1. The relationship of the proposed use to the comprehensive plan, growth management
regulations, critical area regulations, the shoreline management program and floodplain management
program for the area;
2. The potential of the proposed development project to destroy or adversely affect a fish and
wildlife habitat conservation area or create an adverse effect to federal, state or locally protected
species or habitat;
3. Is the minimum necessary to grant relief; and,
B. In addition to the Criteria outlined in ACC 18.70.025, no variance shall be granted to the requirements
of this ordinance unless the applicant demonstrates that:
1. The project will not adversely affect features or quality of habitat supporting local, state or
federally protected fish or wildlife;
C. Variances may be requested for new construction, substantial improvements, and other development
for the conduct of functionally dependent uses provided:
1. There is good and sufficient cause for providing relief;
2. The variance is the minimum necessary to provide relief;
3. The variance does not cause a rise in the 100-year flood level within the regulatory floodplain;
4. The project will not adversely affect federal, state or locally protected fish, wildlife and their
habitat or the functions associated with their habitat.
D. Variances shall only be issued:
1. Upon a determination that the granting of a variance will not result in increased flood heights,
additional threats to public safety, extraordinary public expense, create nuisances, cause
fraud on or victimization of the public, or conflict with existing local laws or ordinances;
2. For the repair, rehabilitation, or restoration of historic structures upon a determination that the
proposed repair or rehabilitation will not preclude the structure’s continued designation as a
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historic structure and the variance is the minimum necessary to preserve the historic character
and design of the structure;
3. Upon a determination that failure to grant the variance would result in exceptional hardship to
the applicant;
4. Upon a showing that the use cannot perform its intended purpose unless it is located or
carried out in close proximity to water. This includes only facilities defined in Section 2 of this
ordinance in the definition of “Functionally Dependent Use.”
E. Variances shall not be issued within any floodway if any increase in flood levels during the base flood
discharge would result.
F. Generally, variances may be issued for new construction and substantial improvements to be erected
on a lot of one-half acre or less in size contiguous to and surrounded by lots with existing structures
constructed below the BFE, provided the procedures of Sections 4 and 5 of this ordinance have been fully
considered. As the lot size increases beyond one-half acre, the technical justification required for issuing the
variance increases.
G. In considering variance applications, the {Governing Body} shall consider all technical evaluations, all
relevant factors, all standards specified in other sections of this ordinance, and:
1. The danger that materials may be swept onto other lands to the injury of others;
2. The danger to life and property due to flooding or erosion damage;
3. The susceptibility of the proposed facility and its contents to flood damage and the effect
of such damage on the individual owner;
4. The importance of the services provided by the proposed facility to the community;
5. The necessity to the facility of a waterfront location, where applicable;
6. The availability of alternative locations for the proposed use, which are not subject to
flooding or erosion damage;
7. The compatibility of the proposed use with existing and anticipated development;
8. The relationship of the proposed use to the comprehensive plan and floodplain
management program for that area;
9. The safety of access to the property in time of flood for ordinary and emergency vehicles;
10. The expected heights, velocity, duration, rate of rise, and sediment transport of the
floodwaters expected at the site; and,
11. The costs of providing governmental services during and after flood conditions, including
maintenance and repair of public utilities and facilities, such as sewer, gas, electrical, water
system, and streets and bridges.
Section 5. General Development Standards
The provisions of Section 5 shall apply in the Special Flood Hazard Area:
15.68.260 Subdivisions.
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This section applies to all subdivision proposals, including short subdivisions, preliminary subdivisions, binding
site plans, and expansions to manufactured home parks as defined in Chapter 17.04 ACC.
A. All proposals shall be consistent with the need to minimize flood damage.
B. The proposed subdivision must have one or more new lots in the Special Flood Hazard Area set aside
for open space use through deed restriction, easement, subdivision covenant, or donation to a public agency.
1. In the Special Flood Hazard Area outside the Protected Area, zoning must maintain a low
density of floodplain development.
2. In the Special Flood Hazard Area outside the protected area in which the current zoning is
less than 5 acres must maintain current zoning.
3. The density of development in the portion of the development outside the Special Flood
Hazard Area may be increased to compensate for the amount of land in the Special Flood Hazard
Area preserved as open space in accordance with Chapter 17.25 ACC.
C. If a parcel has a buildable site outside the Special Flood Hazard Area, it shall not be subdivided to
create a new lot that does not have a buildable site outside of the Special Flood Hazard Area. This provision
does not apply to tracts that are to be preserved as open space.
D. All proposals shall have utilities and facilities, such as sewer, gas, electrical, and water systems
located and constructed to prevent flood damage.
E. All proposals shall ensure that all subdivisions have at least one access road connected to land
outside the Special Flood Hazard Area with the surface of the road at or above the FPE wherever possible.
Additional access roads may be required based on the number of proposed lots per the current City of Auburn
Engineering Design Standards.
F. All proposals shall have adequate drainage provided to avoid exposure to water damage.
G. The final recorded plat shall include a notice that part of the property is in the SFHA, riparian buffer
zone and/or channel migration area, as appropriate.
15.68.270 Site Design.
A. Structures and other development shall be located to avoid flood damage or that adequately mitigates
any identified impacts.
1. If a lot has a buildable site out of the Special Flood Hazard Area, all new structures shall be
located in that area, when possible.
2. If a lot does not have a buildable site out of the Special Flood Hazard Area, all new structures,
pavement, and other development must be sited in the location that has the least impact on habitat by
locating the development as far from the water body as possible or by placing the structure on the
highest portion of the lot.
3. A minimum setback of 15 feet from the Protected Area shall be required for all structures.
4. If the proposed project does not meet the criteria of Section 15.68.270(A) through (B), a
habitat impact assessment shall be conducted pursuant to Section 15.68.440 and, if necessary, a
habitat mitigation plan shall be prepared and implemented pursuant to Section 15.68.450.
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B. All new development shall be designed and located to minimize the impact on flood flows, flood
storage, water quality and habitat.
1. Stormwater and drainage features shall incorporate low impact development techniques, if
technically feasible, that mimic pre-development hydrologic conditions, such as stormwater infiltration,
rain gardens, grass swales, filter strips, disconnected hard surface areas, permeable pavement,
vegetative roof systems, etc. per the City’s current SWMM per Chapter 12.04 ACC.
2. If the proposed project will create new hard surfaces so that more than 10 percent of the
portion of the lot in the Special Flood Hazard Area is covered by hard surface, the applicant shall
demonstrate that there will be no net increase in the rate and volume of the stormwater surface runoff
per the maximum extent feasible and as required per the City’s current SWMM per ACC 13.48 that
leaves the site or that the adverse impact is mitigated, as provided in Sections 15.68.440 and
15.68.450.
C. The site plan required in Section 15.68.170 shall account for surface drainage to ensure that:
1. Existing and new buildings on the site will be protected from stormwater runoff; and
2. The project will not divert or increase surface water runoff onto neighboring properties.
15.68.280 Hazardous Materials.
A. No new development shall create a threat to public health, public safety or water quality. Chemicals,
explosives, gasoline, propane, buoyant materials, animal wastes, fertilizers, flammable liquids, pollutants, or
other materials that are hazardous, toxic, or a threat to water quality are prohibited from the Special Flood
Hazard Area. This prohibition does not apply to small quantities of these materials kept for normal household
use. This prohibition does not apply to the continued operations of existing facilities and structure, reuse of
existing facilities and structures, or functionally dependent facilities or structures.
B. If the proposed project cannot meet Section 15.68.280(A) of this ordinance, then a habitat impact
assessment must be conducted in accordance with Sections 15.68.440 and 15.68.450.
15.68.290 Critical Facilities.
A. Construction of new critical facilities shall be, to the extent possible, located outside the limits of the
Special Flood Hazard Area.
B. Construction of new critical facilities in the Special Flood Hazard Area shall be permissible if no
feasible alternative site is available, provided;
1. Critical facilities shall have the lowest floor elevated three feet above the base flood elevation
or to the height of the 500-year flood, whichever is higher. If there is no available data on the 500-year
flood, the permit applicants shall develop the needed data in accordance with FEMA mapping
guidelines.
2. Access to and from the critical facility shall be protected to the elevation of the 500-year
floodplain. Access routes elevated to or above the level of the base flood elevation shall be provided to
all critical facilities to the extent possible.
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Section 6. Standards for Protection of Structures
15.68.300 Applicability.
The protection requirements in this section apply to all new structures and substantial improvements, which
include:
A. Construction or placement of a new structure.
B. Reconstruction, rehabilitation, or other improvement that will result in a substantially improved building.
C. Repairs to an existing building that has been substantially damaged.
D. Placing a manufactured home on a site.
E. Placing an occupied recreational vehicle or travel trailer on a site for more than 180 days.
15.68.310 Flood Protection Standards.
A. All new structures and substantial improvements shall have the lowest floor, including basement,
elevated above the FPE.
B. New construction and substantial improvement of any residential structure in an Unnumbered A zone
for which a BFE is not available and cannot be reasonably obtained shall be reasonably safe from flooding, but
in all cases the lowest floor shall be at least two feet above the Highest Adjacent Grade.
C. The structure shall be aligned parallel with the direction of flood flows where practicable.
D. The structure shall be anchored to prevent flotation, collapse, or lateral movement of the structure
resulting from hydrodynamic and hydrostatic loads including the effects of buoyancy.
E. All manufactured homes shall be anchored to prevent flotation, collapse, or lateral movement, and
shall be installed using methods and practices that minimize flood damage. Anchoring methods may include,
but are not limited to, use of over-the-top or frame ties to ground anchors.
F. All materials below the FPE shall be resistant to flood damage and firmly anchored to prevent flotation.
Materials harmful to aquatic wildlife, such as creosote, are prohibited below the FPE.
G. All new construction and substantial improvements shall be constructed using methods and practices
that minimize flood damage
H. Electrical, heating, ventilation, duct work, plumbing, and air-conditioning equipment and other service
facilities shall be elevated above the FPE. Water, sewage, electrical, and other utility lines (excluding storm
drainage facilities) below the FPE shall be constructed so as to minimize water from entering or accumulating
within them during conditioning of flooding.
I. Fully enclosed areas below the lowest floor that are subject to flooding shall be used only for parking,
limited storage, or building access and 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 shall either
be certified by a registered professional engineer or licensed architect in the State of Washington and/or meet
or exceed the following minimum criteria:
1. A minimum of two openings having a total net area not less than one square inch for every
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.
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3. Openings must be equipped with screens, louvers, or other coverings or devices provided that
they permit the automatic entry and exit of floodwaters.
4. A garage attached to a residential structure, constructed with the garage floor slab below the
BFE, must be designed to allow for the automatic entry and exit of flood waters.
15.68.320 Nonresidential Construction.
New construction and substantial improvement of any commercial, industrial, or other nonresidential structure
shall meet the requirements of subsection A or B below:
A. New construction and substantial improvement of any commercial, industrial or other nonresidential
structure shall meet all of the following requirements:
1. In AE and A1-30 zones or other A zoned areas where the BFE has been determined or can
be reasonably obtained:
2. New construction and substantial improvement of any commercial, industrial, or other
nonresidential structure shall have the lowest floor, including basement, elevated one foot or more
above the BFE, or elevated as required by ASCE 24, whichever is greater. Mechanical equipment and
utilities shall be waterproofed or elevated least one foot above the BFE, or as required by ASCE 24,
whichever is greater. If located in an AO zone, the structure shall either:
a. 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
b. 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 substantially
impermeable to the passage of water and with structural components having the capability of
resisting hydrostatic and hydrodynamic loads and effects of buoyancy. If this method is used,
compliance shall be certified by a registered professional engineer, or architect as in Section
15.68.220(B).
3. If located in an Unnumbered A zone for which a BFE is not available and cannot be
reasonably obtained, the structure shall be reasonably safe from flooding, but in all cases the lowest
floor shall be at least two feet above the Highest Adjacent Grade.
4. If buildings are constructed or substantially improved with fully enclosed areas below the
lowest floor, that are subject to flooding, the areas shall be used only for parking, limited storage, or
building access, and shall be designed to automatically equalize hydrostatic flood forces on exterior
walls by allowing for the entry and exit of floodwaters. Designs for meeting this requirement must either
be certified by a registered professional engineer or architect or must meet or exceed the following
minimum criteria:
a. Have a minimum of two openings with a total net area of not less than one square
inch for every square foot of enclosed area subject to flooding.
b. The bottom of all openings shall be no higher than one foot above grade.
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c. Openings may be equipped with screens, louvers, valves, or other coverings or
devices provided that they permit the automatic entry and exit of floodwater.
d. A garage attached to a residential structure, constructed with the garage floor slab
below the BFE, must be designed to allow for the automatic entry and exit of flood waters.
5. Alternatively, a registered engineer or architect may design and certify engineered openings.
B. If the requirements of Section 15.68.320(A) are not met, then new construction and substantial
improvement of any commercial, industrial or other nonresidential structure shall meet all of the following
requirements:
1. Be dry floodproofed so that below one foot or more above the base flood level the structure is
watertight with walls substantially impermeable to the passage of water or dry floodproofed to the
elevation required by ASCE 24, whichever is greater;
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 the structural design, specifications and
plans. Such certifications shall be provided to the official as set forth in Section 15.68.220(B);
4. Nonresidential structures that are elevated, not floodproofed, must meet the same standards
for space below the lowest floor as described in 15.68.320(A)(2);
15.68.330 Manufactured Homes.
All manufactured homes to be placed or substantially improved on sites shall be:
A. Elevated on a permanent foundation in accordance with Section 15.68.310(A) and
B. Securely anchored to an adequately anchored foundation system to resist flotation, collapse and
lateral movement. Methods of anchoring may include, but are not to be limited to, use of over-the-top or frame
ties to ground anchors. This requirement is in addition to other applicable anchoring requirements for resisting
wind forces.
C. If manufactured homes are constructed or substantially improved with fully enclosed areas below
the lowest floor, the areas shall be used solely for parking of vehicles, building access, or storage.
15.68.340 Recreational Vehicles.
Recreational vehicles placed on sites shall:
A. Be on the site for fewer than 180 consecutive days, or
B. Be fully licensed and ready for highway use, on their wheels or jacking system, attached to the site
only by quick disconnect type utilities and security devices, and have no permanently attached addition; or
C. Meet the requirements of Section 15.68.340 and the anchoring requirements for manufactured homes
in Section 15.68.330.
15.68.350 Appurtenant Structures.
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A structure which is on the same parcel of property as the principle structure and the use of which is incidental
to the use of the principle structure and is not used for human habitation may be exempt from the elevation
requirements of Section 15.68.310(A), provided:
A. It is used only for parking or storage;
B. It is constructed and placed on the building site so as to offer minimum resistance to the flow of
floodwaters;
C. It is anchored to prevent flotation which may result in damage to other structures;
D. All portions of the structure below the FPE must be constructed of flood-resistant materials;
E. Service utilities such as electrical and heating equipment meet the standards of Section 15.68.310(F)
and Section 15.68.360;
F. It has openings to allow free flowage of water that meet the criteria in Section 15.68.310(I);
G. The project meets all the other requirements of this ordinance, including Section 7.
15.68.360 Utilities.
A. All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of
flood waters into the system;
B. New water wells shall be located outside the floodway and shall be protected to the FPE;
C. New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration
of flood waters into the systems and discharges from the systems into the floodwaters;
D. Onsite waste disposal systems shall be located to avoid impairment to them or contamination from
them during flooding. A habitat impact assessment shall be conducted in accordance with Section 15.68.440 as
a condition of approval of an onsite waste disposal system to be located in the Special Flood Hazard Area.
Section 7. Standards for Habitat Protection
The provisions of this Section shall apply in the Special Flood Hazard Area and channel migration zone.
15.68.370 Non-Development Activities.
Activities that do not meet the definition of “development” are allowed in the Special Flood Hazard Area and
Protected Area without the need for a floodplain development permit under this ordinance, provided all other
Federal, State and local requirements are met. The following are examples of activities not considered
development or “unnatural changes to improved or unimproved real estate”.
A. Routine maintenance of landscaping that does not involve grading, excavation or filling;
B. Removal of noxious weeds and hazard trees and replacement of non-native vegetation with native
vegetation;
C. Normal maintenance of structures, such as re-roofing and replacing siding, provided such work does
not qualify as a substantial improvement;
D. Normal maintenance of above ground utilities and facilities, such as replacing downed power lines and
utility poles;
E. Underground and above ground utility work located in previously disturbed areas, with no significant
vegetation impacts, and will have no appreciable change in grade;
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F. Normal maintenance and preservation of public streets and private streets or parking lots (with
approval of Floodplain Administrator) , including, but not limited to filling potholes, patching, crack seal, chip
seal, repaving and installing signs and traffic signs, traffic control devices, striping/channelization, pavement
markings, repair/replacement of sidewalk/curb and gutter, ADA improvements, non-motorized improvements,
repair of guardrails, repair of retaining walls, management of hazardous trees, fencing repair, lighting repair, but
not including expansion of paved areas;
G. Public street improvements with no significant vegetation impacts, and no appreciable change in
grade;
H. Normal maintenance of a levee or other flood control facility prescribed in the operations and
maintenance plan for the levee or flood control facility are allowed in the Special Flood Hazard Area without the
need for a floodplain development permit. Normal maintenance does not include repair from flood damage,
expansion of the prism, expansion of the face or the toe or addition for protection on the face or toe with rock
armor; and
I. Plowing and other normal flood protection practices (other than structures or filling) on farms in the
Special Flood Hazard Area and in existence as of the effective date of this ordinance do not require a floodplain
development permit. Clearing additional land for agriculture after the date of this ordinance will require a
floodplain development permit and a Habitat Assessment.
15.68.380 Activities Allowed with a Floodplain Development Permit.
The following activities are allowed in the Special Flood Hazard Area without the analysis required in Section
15.68.410 or the habitat impact assessment required under Section 15.68.440, provided that all other
requirements of this ordinance are met, including obtaining a floodplain development permit:
A. Repairs or remodeling of an existing structure, provided that the repairs or remodeling are not a
substantial improvement or a repair of substantial damage.
B. Expansion or reconstruction of an existing structure that is no greater than ten percent beyond its
existing footprint, provided that the repairs or remodeling are not a substantial improvement or repair of
substantial damage. If the structure is in the floodway, there shall be no change in the structure’s dimensions
perpendicular to flow.
C. Activities with the sole purpose of creating, restoring or enhancing natural functions associated with
floodplains, streams, lakes, estuaries, marine areas, habitat and riparian areas that meet Federal and State
standards, provided the activities do not include structures, grading, fill, or hard surfaces.
D. Development of open space and recreational facilities such as parks, trails and hunting grounds, that
do not include structures, fill, hard surfaces or removal of more than five percent of the native vegetation on
that portion of the property in the Special Flood Hazard Area.
E. Repairs to onsite Septic Systems provided the ground disturbance is the minimum necessary and best
management practices (BMP’s) to prevent stormwater runoff and soil erosion are used.
15.68.390 Other Activities.
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All other activities listed in Sections 15.68.370 or 15.68.380 that are allowed by Title 18 (Zoning) of the Auburn
City Code are allowed, provided they meet all the other requirements of this ordinance, including the analysis
required under Section 15.68.420, 15.68.430, and the habitat impact assessment required under Section
15.68.440, and a floodplain development permit is issued.
15.68.400 Native Vegetation.
The site plan required in the Floodplain Development Application Packet shall show existing native vegetation.
A. Within the riparian buffer zone, native vegetation shall be left undisturbed, except as provided in
Sections 15.68.370 and 15.68.380(C).
B. Outside the riparian buffer zone, removal of native vegetation shall not exceed 35 percent of the
surface area of the portion of the site in the Special Flood Hazard Area. Native vegetation in the riparian buffer
zone portion of the property can be counted toward this requirement.
C. If the proposed project does not meet the criteria of Sections 15.68.400(A) and (B), a habitat impact
assessment shall be conducted pursuant to Section 15.68.440 and, if necessary, a habitat mitigation plan shall
be prepared and implemented pursuant to Section 15.68.450.
15.68.410 Floodway Standards.
A. In addition to the other requirements of this ordinance, a project to develop in the floodway as
delineated pursuant to Sections 15.68.130(C), 15.68.130(D) or 15.68.150(E) shall meet the following criteria:
1. The applicant shall provide a certification by a registered professional engineer licensed in the
State of Washington demonstrating through hydrologic and hydraulic analyses performed in
accordance with standard engineering practices that the proposed development would 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 the following. The following exceptions must still meet all other requirements in
the ordinance, including Section 15.68.410(A)(1).
a. Repairs, reconstruction, or improvements to a residential structure that do not
increase the ground floor area, providing the cost of which does not exceed 50 percent of the
market value of the structure either, (1) before the repair, or reconstruction is started, or (2) if
the structure has been damaged, and is being restored, before the damage occurred. Any
project for improvement of a structure to correct existing violations of State or local health,
sanitary, or safety code specifications that have been identified by a local code enforcement
official, and which are the minimum necessary to assure safe living conditions, or to an
historic structure, may be excluded from the 50 percent calculation;
b. Repairs, reconstruction, replacement, or improvements to existing farmhouse
structures located in designated floodways and that are located on lands designated as
agricultural lands of long-term commercial significance under RCW 36.70A.170 may be
permitted subject to the following:
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i. The new farmhouse is a replacement for an existing farmhouse on the same
farm site;
ii. There is no potential building site for a replacement farmhouse on the same
farm outside the designated floodway;
iii. Repairs, reconstruction, or improvements to a farmhouse shall not increase
the total square footage of encroachment of the existing farmhouse;
iv. A replacement farmhouse shall not exceed the total square footage of
encroachment of the farmhouse it is replacing;
v. A farmhouse being replaced shall be removed, in its entirety, including
foundation, from the floodway within ninety days after occupancy of a new farmhouse;
vi. For substantial improvements and replacement farmhouses, the elevation of
the lowest floor of the improvement and farmhouse respectively, including basement,
is a minimum of one foot higher than the BFE;
vii. New and replacement water supply systems are designed to eliminate or
minimize infiltration of floodwaters into the system;
viii. New and replacement sanitary sewerage systems are designed and located
to eliminate or minimize infiltration of floodwater into the system and discharge from
the system into the floodwaters; and
ix. All other utilities and connections to public utilities are designed, constructed,
and located to eliminate or minimize flood damage.
c. For all substantially damaged residential structures, other than farmhouses, located
in a designated floodway, the Floodplain Administrator may make a written request that the
Department of Ecology assess the risk of harm to life and property posed by the specific
conditions of the floodway. Based on analysis of depth, velocity, flood-related erosion,
channel migration, debris load potential, and flood warning capability, the Department of
Ecology may exercise best professional judgment in recommending to the local permitting
authority repair, replacement, or relocation of a substantially damaged structure consistent
with WAC 173-158-076. The property owner shall be responsible for submitting to the local
government and the Department of Ecology any information necessary to complete the
assessment. Without a favorable recommendation from the department for the repair or
replacement of a substantially damaged residential structure located in the regulatory
floodway, no repair or replacement is allowed per WAC 173-158-070(1).
d. Before the repair, replacement, or reconstruction is started, all requirements of the
NFIP, the state requirements adopted pursuant to 86.16 RCW, and all applicable local
regulations must be satisfied. In addition, the following conditions must be met:
i. There is no potential safe building location for the replacement
residential structure on the same property outside the regulatory floodway.
ii. A replacement residential structure is a residential structure built as a
substitute for a legally existing residential structure of equivalent use and size.
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iii. Repairs, reconstruction, or replacement of a residential structure shall
not increase the total square footage of floodway encroachment.
iv. The elevation of the lowest floor of the substantially damaged or
replacement residential structure is a minimum of one foot higher than the BFE.
v. New and replacement water supply systems are designed to eliminate or
minimize infiltration of floodwater into the system.
vi. New and replacement sanitary sewerage systems are designed and
located to eliminate or minimize infiltration of floodwater into the system and
discharge from the system into the floodwaters.
vii. All other utilities and connections to public utilities are designed,
constructed, and located to eliminate or minimize flood damage.
e. Repairs, reconstruction, or improvements to residential structures identified as
historic structures that do not increase the building’s dimensions.
B. In riverine Special Flood Hazard Areas where a floodway has not been delineated pursuant to
Sections 15.68.130(C), 15.68.130(D) or 15.68.150(E), the applicant for a project to develop in the SFHA shall
provide a certification by a registered professional engineer in the State of Washington demonstrating through
hydrologic and hydraulic analyses performed in accordance with standard engineering practices that the
proposed development and all other past or future similar developments would not cumulatively result in an
increase of flood levels during the occurrence of the base flood discharge by more than one-half foot.
15.68.420 Standards for Shallow Flooding Areas (AO Zones)
Shallow flooding areas appear on FIRMs as AO zones with depth designations. The base flood depths in these
zones range from 1 to 3 feet above ground where a clearly defined channel does not exist, or where the path of
flooding is unpredictable and where velocity flow may be evident. Such flooding is usually characterized as
sheet flow. In addition to other provisions in this code, the following additional provisions also apply in AO
zones.
A. New construction and substantial improvements of residential structures and manufactured homes
within AO zones shall have the lowest floor (including basement and mechanical equipment) elevated above
the highest adjacent grade to the structure, one foot or more above the depth number specified in feet on the
community’s FIRM (at least two feet above the highest adjacent grade to the structure if no depth number is
specified).
B. New construction and substantial improvements of nonresidential structures within AO zones shall
either:
1. 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
2. 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 substantially
impermeable to the passage of water and with structural components having the capability of
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resisting hydrostatic and hydrodynamic loads and effects of buoyancy. If this method is used,
compliance shall be certified by a registered professional engineer, or architect as in Section
15.68.310(I).
C. Require adequate drainage paths around structures on slopes to guide floodwaters around and away
from proposed structures.
D. Recreational vehicles placed on sites within AO zones on the community’s FIRM either:
1. Be on the site for fewer than 180 consecutive days, or
2. 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
3. Meet the requirements of subsections (1) and (3) above and the anchoring requirements for
manufactured homes (Section 15.68.330(B)).
15.68.430 Compensatory Storage.
New development shall not reduce the effective flood storage volume of the Special Flood Hazard Area. A
development proposal shall provide compensatory storage if grading or other activity eliminates any effective
flood storage volume. Compensatory storage shall:
A. Provide equivalent volumes at equivalent elevations to that being displaced. For this purpose,
“equivalent elevation” means having similar relationship to ordinary high water mark and to the best available
10-year, 50-year and 100-year water surface profiles.
B. Be hydraulically connected to the source of flooding.
C. Provide compensatory storage in the same construction season as when the displacement of flood
storage volume occurs and before the flood season begins.
D. The newly created storage area shall be graded and vegetated to allow fish access during flood events
without creating fish stranding sites.
15.68.440 Habitat Impact Assessment.
Unless allowed under Sections 15.68.370 and 15.68.380, a permit application to develop in the Special Flood
Hazard Area shall include an assessment of the impact of the project on federal, state or locally protected
species and habitat, water quality and aquatic and riparian habitat. The assessment shall be:
A. A Biological Evaluation or Biological Assessment developed per 50 C.F.R., Subsection 402.12 to
initiate Federal Interagency consultation under Endangered Species Act Section 7.a.2; or,
B. Documentation that the activity fits within Section 4.d of the Endangered Species Act; or,
C. Documentation that the activity fits within a Habitat Conservation Plan approved pursuant to Section
10 of the Endangered Species Act, where any such assessment has been prepared or is otherwise made
available; or
D. An assessment prepared in accordance with Regional Guidance for Floodplain Habitat Assessment
and Mitigation, FEMA Region X, 2013. The assessment shall determine if the project would adversely affect:
1. Species that are Federal, state or local listed as threatened or endangered.
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2. The primary constituent elements for critical habitat when delineated, including but not limited
to water quality, water quantity, flood volumes, flood velocities, spawning substrate, and/or floodplain
refugia for listed salmonids.
3. Essential Fish Habitat designated by the National Marine Fisheries Service.
4. Fish and wildlife habitat conservation areas.
5. Other protected areas and elements necessary for species conservation.
15.68.450 Habitat Mitigation Plan.
A. If the assessment conducted under Section 15.68.440 concludes the project is expected to have an
adverse effect on water quality and/or aquatic or riparian habitat or habitat function, the applicant shall provide
a plan to mitigate those impacts, in accordance with Regional Guidance for Floodplain Habitat Assessment and
Mitigation, FEMA Region X, 2013.
1. If the USFWS or NMFS issues an Incidental Take Permit under Section 10 of the Endangered
Species Act or a Biological Opinion under Section 7 of the Endangered Species Act; then it can be
considered to quality as a plan to mitigate those impacts.
2. If the project is located in the Protected Area, the mitigation plan shall stipulate avoidance
measures as are needed to ensure that there is no adverse effect during any phase of the project. No
compensatory mitigation is allowed in the Protected Area.
3. If the project is located outside the Protected Area, the mitigation plan shall include such
avoidance, minimization, restoration, or compensation measures so that indirect adverse effects of
development are mitigated such that equivalent or better habitat protection is provided for the following
functions:
a. Stormwater: Reduce flood volumes and stormwater runoff from new development by
ensuring that increased volumes of stormwater reach the river at the same frequency, timing
and duration as historical runoff. Low Impact Development (LID) is required to be incorporated
as described in Section 15.68.270(B).
b. Riparian Vegetation: Maintain or replace riparian function by providing equivalent
area, diversity, and function of riparian vegetation as currently exists on the site. Riparian
retention requirements are outlined in ACC 15.68.400.
c. Hyporheic Zones: No activity is allowed that interferes with the natural exchange of
flow between surface water, groundwater and hyporheic zone, however, natural hyporheic
exchange may be enhanced or restored.
d. Wetlands: Wetland function must be maintained or replaced by providing equivalent
function.
e. Large Woody Debris: Any large woody debris (LWD) removed from the floodplain
must be replaced in kind, replicating or improving the quantity, size, and species of the
existing LWD per Washington Department of Fish and Wildlife Aquatic Habitat Guidelines.
4. No new stream crossings are allowed outside the Protected Area unless approval has been
obtained as stated in Section 15.68.460(A).
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B. The plan’s habitat mitigation activities shall be incorporated into the proposed project. The floodplain
development permit shall be based on the redesigned project and its mitigation components.
C. As required in Section 15.68.230, the floodplain administrator or designee shall not issue a certificate
of occupancy or final permits until all work identified in the Habitat Assessment and mitigation plan has been
completed or the applicant has provided the necessary assurance that unfinished portions of the project will be
completed, in accordance with Section 15.68.230(A).
D. Third-Party Review. For the habitat impact assessment required in Subsection 15.68.440 or the habitat
mitigation plan required in this section, the city may require third-party review when the professional opinions of
the applicant’s representative and the city’s reviewers cannot be reconciled. Third-party review requires the
applicant’s habitat impact assessment, habitat mitigation plan, and/or additional technical studies to be
reviewed by an independent third party, paid for by the applicant but hired by the city. Third-party review shall
be conducted by a qualified consultant as defined in the Floodplain Habitat Assessment and Mitigation
Regional Guidance, FEMA Region X, 2013.
15.68.460 Alteration of Watercourses.
A. In addition to the other requirements in Chapter 15.68, if a project will alter or relocate boundaries of
the SFHA, then the applicant shall also submit a request for a Conditional Letter of Map Revision (CLOMR),
where required by FEMA with engineering documentation and analysis regarding the proposed change. The
project will not be approved unless FEMA issues the CLOMR (which requires Endangered Species Act
consultation) and the provisions of the letter are made part of the permit requirements. If the change to the BFE
or boundaries of the SFHA would normally require a Letter of Map Change, then the project proponent shall
initiate, and receive approval of, a Conditional Letter of Map Revision (CLOMR) prior to approval of the
development permit. The project shall be constructed in a manner consistent with the approved CLOMR.
B. If a CLOMR application is made, then the project proponent shall also supply the full CLOMR
documentation package to the Floodplain Administrator to be attached to the floodplain development permit,
including all required property owner notifications.
C. The floodplain administrator or designee shall notify adjacent communities and the Washington
Department of Ecology prior to any alteration or relocation of a watercourse, and submit evidence of such
notification to FEMA.
D. Maintenance shall be provided within the altered or relocated portion of said watercourse so that the
flood carrying capacity is not diminished. If the maintenance program does not call for cutting of native
vegetation, the system shall be oversized at the time of construction to compensate for said vegetation growth
or any other natural factor that may need future maintenance.
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Chapter 15.68
FLOOD HAZARD AREASFLOODPLAIN DEVELOPMENT MANAGEMENT
Sections:
Article I. Purpose
15.68.010 Reserved.
15.68.020 Reserved.
15.68.030 Statement of purpose.
15.68.040 Methods of reducing flood losses.
Article II. Definitions
15.68.050 Interpretation of language.
15.68.060 Definitions.
Article III. General Provisions
15.68.070 Land to which this chapter applies.
15.68.080 Reserved.
15.68.090 Penalties for noncompliance.
15.68.100 Abrogation and greater restrictions.
15.68.110 Interpretation.
15.68.120 Warning and disclaimer of liability.
15.68.125 Appeals.
Article IV. Administration
15.68.130 Establishment of and requirement to obtain floodplain development permit.
15.68.135 Floodplain development permit application.
15.68.136 Floodplain development permit expiration.
15.68.140 Designation of the floodplain administrator.
15.68.141 Duties of the floodplain administrator.
15.68.150 Duties and responsibilities of the public works department.
15.68.151 Duties and responsibilities of the planning and development department.
Article V. Provisions for Flood Hazard Protection
15.68.160 Standards of the public works department.
15.68.161 Standards of the planning and development department.
15.68.170 Additional standards of the planning and development department.
15.68.180 Floodways and community acknowledgement of FEMA map amendments.
15.68.190 Developments within areas of special flood hazard.
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15.68.200 Compensatory storage requirements.
Prior legislation: Ords. 4214 and 4220.
Article I. Purpose
Section 1. General
15.68.010 Statutory Authorization.
15.68.020 Purpose.
15.68.030 Lands to which this Ordinance Applies.
15.68.040 Approach.
15.68.050 Penalties for Non-Compliance.
15.68.060 Interpretation.
15.68.070 Abrogation and Greater Restrictions.
15.68.080 Warning and Disclaimer of Liability.
15.68.090 Severability.
Section 2. Definitions
15.68.100 Definitions.
Section 3. Regulatory Data
15.68.110 Area to be Regulated.
15.68.120 Special Flood Hazard Area.
15.68.130 Flood Hazard Data.
15.68.140 Protected Area.
15.68.150 New Regulatory Data.
Section 4. Administration
15.68.160 Establishment of Floodplain Development Permit.
15.68.170 Floodplain Development Permit Application.
15.68.180 Floodplain Development Permit Expiration.
15.68.190 Designation of the Floodplain Administrator.
15.68.200 Duties of the Floodplain Administrator.
15.68.210 Notification to Other Entities.
15.68.220 Records.
15.68.230 Certificate of Occupancy.
15.68.240 Appeals.
15.68.250 Variance Criteria.
Section 5. General Development Standards
15.68.260 Subdivisions.
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15.68.270 Site Design.
15.68.280 Hazardous Materials.
15.68.290 Critical Facilities.
Section 6. Standards for Protection of Structures
15.68.300 Applicability.
15.68.310 Flood Protection Standards.
15.68.320 Nonresidential Construction.
15.68.330 Manufactured Homes.
15.68.340 Recreation Vehicles.
15.68.350 Appurtenant Structures.
15.68.360 Utilities.
Section 7. Standards for Habitat Protection
15.68.370 Non-Development Activities.
15.68.380 Activities Allowed with a Floodplain Development Permit.
15.68.390 Other Activities.
15.68.400 Native Vegetation.
15.68.410 Floodway Standards.
15.68.420 Standards for Shallow Flooding Areas (AO Zones)
15.68.430 Compensatory Storage.
15.68.440 Habitat Impact Assessment.
15.68.450 Habitat Mitigation Plan.
15.68.460 Alteration of Watercourses.
Section 1. General
15.68.010 Reserved Statutory Authorization.
A. The Legislature of the State of Washington has delegated the responsibility to local governmental units
to adopt regulations designed to promote the public health, safety and general welfare of its citizenry.
Therefore, the City does ordain as follows:
B. Findings of Fact:
Areas of Auburn are subject to periodic inundation and channel migration which may result in loss of life and
property, health and safety hazards, disruption of commerce and governmental services, extraordinary public
expenditures for protection and relief from flooding and channel migration, and impairment of the tax base, all
of which adversely affect the public health, safety and general welfare.
When floodplains and watersheds are developed without taking appropriate care and precautions, flood
heights, frequencies, and velocities increase, which may cause a greater threat to humans, damage to
property, destruction of natural floodplain functions, and adverse impacts to water quality and habitat.
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Rivers, streams, lakes, estuarine and marine areas and their floodplains are major elements of healthy aquatic
and riparian areas and conveyance of flood waters. If watersheds, rivers, streams, lakes, estuaries, floodplains
and other systems are not viewed holistically as biological and geomorphologic units, it may lead to serious
degradation of habitat and increased flood hazards to people and human development.
Over the years, natural processes have evolved that manage flood waters and channel flows in the most
effective and efficient manner. Disruption of these processes through alterations to land cover, stream
channels, wetlands and other water bodies which may lead to increased flood hazards, loss of life and
property, threats to public health, and loss of habitat.
15.68.020 Reserved Purpose.
15.68.030 Statement of purpose.
It is the purpose of this chapterordinance 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 to manage
development in order to:
A. . To protect. Protect human life, health, and to protect property from the dangers of flooding;
B. B. To minimizeMinimize the need for publicly funded and hazardous rescue efforts to save those who
are isolated by floodwaters;
B.C. Minimize expenditure of public money andfor costly flood damage repair and flood control projects;
C. To minimize the need for rescue and relief efforts associated with flooding and generally undertaken at the
expense of the general public;
D. To minimize prolonged business interruptions;
D. E. To minimizeMinimize disruption of commerce, governmental services, and government
infrastructure;
C.E. 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;the floodplain.;
F. Minimize cost impacts to public facilities and utilities such as water and gas mains, electric, telephone
and sewer lines, streets and bridges located in the special flood hazard area.;
D.G. F. To help maintainMaintain a stable tax base by providing for the sound use and development of and
development of flood hazard areas of special flood hazard soso as to minimize future flood bblight areas
caused by flooding;
G. To ensure that potential buyers are notified that property is in an area of special flood hazard;
H. To ensure thatEncourage those who occupy flood hazard the areas of special flood hazard assume
responsibility for their actions;
H. I. To qualify be educated about the cityrisks and challenges associated with these areas.;
E.I. IQualify the City of Auburn for participation in the National Flood Insurance Program, thereby giving
citizens and businesses the opportunity to purchase flood insurance;
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F.J. J. To maintainMaintain the quality of water in rivers, streams, and lakes, and their floodplains so as to
protect public water supplies, areas of the public trustPublic Trust, and wildlife habitat protected by the
Endangered Species Act;
G.K. K. To retainRetain the natural channel, shoreline, and floodplain creation processes and other natural
floodplain functions that protect, create, and maintain habitat for threatened and endangered species; and
H.L. L. To preventPrevent or minimize loss of hydraulic, geomorphic, and ecological functions of
floodplains and stream channels.
15.68.030 Lands to which this Ordinance Applies.
This ordinance shall apply to the Special Flood Hazard Area (SFHA) and associated protected areas within the
jurisdiction of the City of Auburn as defined in Section 3 of this Ordinance.
15.68.040 Methods of reducing flood losses Approach.
In order to accomplish itsachieve the listed purposes, this chapter includes methods and provisions
forordinance:
A. 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;
A. Defines and clarifies the terms and phrases used in this ordinance in Section 2.
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 protective barriers which help
accommodate or channel floodwaters;
D. Controlling filling, grading, dredging, and other development which may increase flood damage;
E. Preventing or regulating the construction of flood barriers which will unnaturally divert floodwaters or which
may increase flood hazardsIdentifies in other areas;
B. F. Identifying the regulatory floodplain, the special flood hazard area, andSection 3 the protected
areaSpecial Flood Hazard Area, the Protected Area and the supporting technical data needed to delineate
those areas;.
C. G. EstablishingEstablishes a permit requirement in Section 4 so that all humanproposed development
that may affect flood hazards, water quality, and habitat is reviewed before it is constructed;prior to
construction.
D. H. SettingSets minimum protection standards in Section 5 for all development to ensure that the
development will not increase the potential for flood damage or adversely affect natural floodplain functions;.
E. I. SettingSets minimum protection standards to protect new and substantially improved structures
from flood damage; and in Section 6.
F. J. SpecifyingSpecifies additional habitat protection criteria. in Section 7. Some small projects do not
need a floodplain development permit (see ACC 15.68.130(B) and (C)); whereas other projects require a
floodplain permit, but do not require the habitat impact assessment required in this chapter (see ACC
15.68.130(D)).15.68.380). For all other development projects, the applicant must assess their impact on those
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factors that contribute to increased flood hazard and degradation of habitat. If the assessment concludes that
therethe project will because an adverse effect outside the Protected Area, the permit will be denied, unless the
project is redesigned to mitigate the adverse effects.impacts are mitigated (avoided, minimized, restored or
compensated for).
Article II. Definitions
15.68.050 Penalties for Noncompliance.
No development shall be undertaken or placed in the areas regulated by this ordinance without full compliance
with the terms of this ordinance and other applicable regulations of the City. 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 be enforced pursuant to the provisions of Chapter 1.25 ACC.
15.68.060 Interpretation of language.
In the interpretation and application of this ordinance, all provisions shall be:
A. Considered as minimum requirements;
B. Liberally construed in favor of the City; and,
B.C. Deemed neither to limit nor repeal any other powers granted under state statutes;
15.68.070 Abrogation and greater restrictions Regulation Conflicts
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
Where this ordinance and another code, or ordinance, conflict or overlap, whichever imposes the more
stringent restrictions shall prevail.
15.68.080 Warning and Disclaimer of Liability.
The degree of property and habitat protection required by this ordinance is considered reasonable for
regulatory purposes and is based on scientific and engineering considerations. Larger floods and movement of
channels outside of mapped channel migration areas may occur on rare occasions. Flood heights may be
increased by manmadeunnatural or natural causes. This ordinance does not imply that land outside the
regulated areas or development permitted within such areas will be free from flood or erosion damage. This
ordinance shall not create liability on the part of the City, any officer or employee thereof, for any damage to
property or habitat that results from reliance on this ordinance or any administrative decision lawfully made
thereunder.
15.68.090 Severability
The provisions and sections of this ordinance shall be deemed separable and the invalidity of any portion of
this ordinance shall not affect the validity of the remainder.
Section 2. Definitions
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15.68.100 Definitions.
Unless specifically defined in this article, wordsbelow, terms or phrases used in this chapterordinance shall be
interpreted so as to give them the meaning they have in common usage and to give this chapterordinance its
most reasonable application.
A. 15.68.060 Definitions.
B. As used in this chapter:
C. . . “Adversely affect/adverse effect” means effects that are a direct or indirect result of the proposed
action or its interrelated or interdependent actions and the effect is not discountable, insignificant, or beneficial,
where:
D. 1. a. . Discountable effects are extremely unlikely to occur; and
E. b. . Insignificant effects relate to the size of the impact and should never reach the scale where a take
occurs. Based on best judgment, a person would not: 1) be able to meaningfully measure, detect, or evaluate
insignificant effects, or 2) expect discountable effects to occur.
F.A. 2. Beneficial effects are contemporaneous positive effects without any adverse effects. In the event
that the overall effect of the proposed action is beneficial, but is also likely to cause some adverse effects, then
the proposed action is considered to result in an adverse effect.
B. . . “Alteration of watercourse” means any action that will change the location of the channel occupied
by water within the banks of any portion of a riverine waterbody.
C. “Appurtenant Structure” means a structure which is on the same parcel as the principle structure to be
insured and the use of which is incidental to the use of the principal structure.
D. “Area of shallow flooding” means a designated zone AO, AH, AR/AO or AR/AH (or VO) on a
community’s Flood Insurance Rate Map (FIRM) with a one percent or greater annual chance of flooding to an
average depth of one to three feet where a clearly defined channel does not exist, where the path of flooding is
unpredictable, and where velocity flow may be evident. Such flooding is characterized by ponding or sheet flow.
Also referred to as the sheet flow area.
E. “Area of special flood hazard” means the land in the floodplain within a community subject to a 1
percent or greater chance of flooding in any given year. It is shown on the Flood Insurance Rate Map (FIRM)
as zone A, AO, AH, A1-30, AE, A99, AR (V, VO, V1-30, VE). “Special flood hazard area” is synonymous in
meaning with the phrase “area of special flood hazard”.
F. “ASCE 24” means the most recently published version of ASCE 24, Flood Resistant Design and
Construction, published by the American Society of Civil Engineers.
G. “Base flood” means the flood having a one percent chance of being equaled or exceeded in any given
year. Also (also referred to as the “100-year flood”). The area subject to the base flood is the special flood
hazard area (SFHA), designated on flood insurance rate maps as Zone A, including AE, AO, AH, and A1 – 99.
H. C. “Base flood elevation” means the elevation of the base flood above the datum of the effective
FIRM.
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I.H. 1. The base flood elevation for the SFHAs of the city shall be as delineated on the 100-year flood
profiles in the flood insurance studyto which floodwater is anticipated to rise during the base flood for the city.
J. 2. The base flood elevation for each SFHA delineated as a Zone AH or Zone AO shall be that
elevation (or depth) delineated on the flood insurance rate map. Where base flood depths are not available in
Zone AO, the base flood elevation shall be considered to be two feet above the highest grade adjacent to the
structure.
K. 3. Where base flood elevation data are not provided on the flood insurance study for the city, base
flood elevation data available from a federal, state, or other authoritative source shall be used, if available.
Where base flood elevation data are not available from other authoritative sources, applicants for approval of
new subdivisions and other proposed developments (including proposals for manufactured home parks and
subdivisions) greater than 50 lots or five acres, whichever is the lesser, shall include such data with their permit
applications. This data must be approved by the floodplain administrator.
L.I. D. “Basement” means any area of the structure having its floor subgrade (below ground level) on all
sides.
J. E. “Building Code” means the currently effective versions of the International Building Code and the
International Residential Code adopted by the Washington State Legislature and any further amendments
adopted by the City of Auburn.
M.K. “Channel migration area”Migration Zone” (CMZ) means the area within the lateral extent of likely
stream channel movement due to stream bank destabilization and erosion, rapid stream incision, aggradation,
avulsions, and shifts in location of stream channels plus 50 feet.
1. 1. The channel migration area shall be the total area occupied by the river channel, the
severe channel migration hazard area, and the moderate channel migration hazard area as delineated
in the Green River Channel Migration Study published by King County dated December 1993 plus 50
feet.
2. Where more than one channel migration zone has been delineated, the floodplain administrator
shall use the delineation that has been adopted for other local regulatory purposes.
2. F. The channel migration area shall be the total area occupied by the river channel, the
severe channel migration hazard area, and the moderate channel migration hazard area as delineated
in the Channel Migration Zone Delineation for the Middle Green River, RM 31.10 to 33.25 dated
December 28, 2018 plus 50-feet which supersedes the study referenced above.
3. A site specific channel migration delineation may also be performed per the Washington State
Department of Ecology’s current requirements with recommended setbacks (A Framework for
Delineating Channel Migration Zones) prepared by a qualified engineer. The delineation shall be
prepared by a qualified consultant as that term is defined in these regulations. The city may retain a
qualified consultant paid for by the applicant to review and confirm the applicant’s reports, studies and
plans if the following circumstances exist:
a. The city has technical information that is unavailable to the applicant; or
b. The applicant has provided inaccurate or incomplete information on previous
proposals or proposals currently under consideration.
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N.L. “Critical facility” means a facility necessary to protect the public health, safety and welfare during a
flood. Critical facilities include, but are not limited to, schools, nursing homes, hospitals, police, fire and
emergency operations installations, water and wastewater treatment plants, electric power stations, and
installations which produce, use, or store hazardous materials or hazardous waste (other than consumer
products containing hazardous substances or hazardous waste intended for household use).
O.M. G. “Development” means any manmadehuman-made change to improved or unimproved real estate
in the regulatory floodplain, including but not limited to buildings or other structures, mining, dredging, filling,
grading, paving, excavation or drilling operations or storage of equipment or materials located within the area of
special flood hazard, subdivision of land, removal of more than five percent of the native vegetation on the
property, or alteration of natural site characteristics.
P.N. H. “Dry floodproofing” means any combination of structural and nonstructural measures that prevent
flood waters from entering a structure.
Q.O. I. “Elevation certificateCertificate” means an administrative tool of the National Flood Insurance
Program (NFIP) that can be used to provide elevation information, to determine the proper insurance premium
rate, and to support a request for a Letter of Map Amendment (LOMA) or Letter of Map Revision based on fill
(LOMR-F).the official form (FEMA Form 81-31) used to provide elevation information necessary to ensure
compliance with provisions of this chapter and determine the proper flood insurance premium rate.
R. J. “Equivalent elevation” means having similar relationship to ordinary high water and to the best
available 10-year, 50-year and 100-year water surface profiles.
P. K. “Essential Facility” has the same meaning as “Essential Facility” defined in ASCE 24. Table 1-1 in
ASCE 24-14 further identifies building occupancies that are essential facilities.
S.Q. “FEMA” means the Federal Emergency Management Agency, the agency responsible for
administering the National Flood Insurance Program.
T. L. “Fish and wildlife habitat conservation area” means lands needed to maintain species in suitable
habitats within their natural geographic distribution so that isolated subpopulations are not created. These
areas are designated by the city pursuant to the Washington State Growth Management Act (WAC 365-190-
080).
U.R. M. “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.
3. N. 3. Mudslides (i.e., mudflows) which are proximately caused by flooding as defined in
paragraph (a)(2) of this definition and are akin to a river of liquid and flowing mud on the surfaces of
normally dry land areas, as when earth is carried by a current of water and deposited along the path of
the current.
4. The collapse or subsidence of land along the shore of a lake or other body of water as a result
of erosion or undermining caused by waves or currents of water exceeding anticipated cyclical levels
or suddenly caused by an unusually high water level in a natural body of water, accompanied by a
severe storm, or by an unanticipated force of nature, such as flash flood or an abnormal tidal surge, or
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by some similarly unusual and unforeseeable event which results in flooding as defined in paragraph
(1)(i) of this definition.
S. “Flood elevation study” means an examination, evaluation and determination of flood hazards and, if
appropriate, corresponding water surface elevations, or an examination, evaluation and determination of
mudslide (i.e., mudflow) and/or flood-related erosion hazards. Also known as a Flood Insurance Study (FIS).
V.T. “Flood insurance rate map (FIRM)” means the official map on which the Federal Insurance
AdministrationEmergency Management Agency has delineated both the areas of special flood hazardSpecial
Flood Hazard Areas and the risk premium zones applicable to the community.
W.U. O. “Flood insurance study” (FIS)” means the official report(s) provided by the Federal Insurance
AdministrationEmergency Management Agency that includes flood profiles, the flood insurance rate map, and
the water surface elevation of the base flood.
V. P. “Floodplain or flood prone area” means any land area susceptible to being inundated by water
from any source. See "Flood or flooding."
W. “Floodplain administrator” means the community official designated by title to administer and enforce
the floodplain management regulations.
X. “Flood proofing” means any combination of structural and nonstructural additions, changes, or
adjustments to structures which reduce or eliminate risk of flood damage to real estate or improved real
property, water and sanitary facilities, structures, and their contents. Flood proofed structures are those that
have the structural integrity and design to be impervious to floodwater below the Base Flood Elevation.
X.Y. “Flood protection elevation (FPE)” means the elevation above the datum of the effective FIRM to which
new and substantially improved structures must be protected from flood damage.
Y.Z. Q. “Floodway” means the channel of a riverstream or other watercourse and the adjacent land areas
that must be reserved in order to discharge the base flood without cumulatively increasing the water surface
elevation more than a designated height. Also referred to the “Regulatory Floodway.one foot. The floodway
shall be as delineated on the flood insurance rate map. Where floodway data are not provided on the flood
insurance study for the city, floodway data available from a federal, state, or other authoritative source shall be
used, if available. Where floodway data is not available from another authoritative source, applicants for
approval of new subdivisions and other proposed developments (including proposals for manufactured home
parks and subdivisions) greater than 50 lots or five acres, whichever is the lesser, shall include such data with
their permit applications. This data must be approved by the floodplain administrator. This provision does not
apply to applications for permits for small projects on large lots, such as constructing a single-family home.
AA. R. “Functionally Dependent Use” means a use which cannot perform its intended purpose unless it is
located or carried out in close proximity to water. The term includes only docking facilities, port facilities that are
necessary for the loading and unloading of cargo or passengers, and ship building and ship repair facilities, and
does not include long-term storage or related manufacturing facilities.
BB. “Highest adjacent grade” means the highest natural elevation of the ground surface prior to
construction next to the proposed walls of a structure.
Z.CC. “Historic structure” means aany structure that is:
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1. . Is listed on . Listed individually in the National Register of Historic Places, the Washington
Heritage Register, or the Washington Heritage Barn Register, or has been designated a landmark or
been issued (a certificate of appropriateness under the city’s historic preservation ordinance.listing
maintained by the Department of Interior) or preliminarily determined by the Secretary of the Interior as
meeting the requirements for individual listing on the National Register;
2. . Has been certified to contribute. Certified or preliminarily determined by the Secretary of the
Interior as contributing to the historical significance of a registered historic district. or a district
preliminarily determined by the Secretary to qualify as a registered historic district;
3. S. Individually listed on a state inventory of historic places in states with historic preservation
programs which have been approved by the Secretary of Interior; or
4. Individually listed on a local inventory of historic places in communities with historic
preservation programs that have been certified either:
a. By an approved state program as determined by the Secretary of the Interior, or
b. Directly by the Secretary of the Interior in states without approved programs.
AA.DD. “Hyporheic zone” means a saturated layer of rock or sediment beneath and/or adjacent to a stream
channel that contains some proportion of channel water or that has been altered by channel water infiltration.
BB.EE. T. “Impervious surface” means a hardnon-vegetated surface area which either prevents or retards the
entry of water into the soil mantle as under natural conditions prior to development. A non-vegetated surface
area which causes water to run off the surface in greater quantities or at an increased rate of flow from the flow
present under natural conditions prior to development. Common impervious surfaces include, but are not
limited to, roof tops, walkways, patios, driveways, parking lots or storage areas, concrete or asphalt paving,
gravel roads, packed earthen materials, and oiled, macadam or other surfaces which similarly impede the
natural infiltration of stormwater.
CC.FF. U. “Lowest floor” means the lowest floor of the lowest enclosed area (including basement) measured
at the walking surface of the floor. 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 as long asprovided 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 in ACC 15.68.170(A)(7). (i.e. provided there
are adequate flood ventilation openings).
DD.GG. V. “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 connectedattached to
the required utilities. For floodplain management purposes, the term “manufactured home” also includes park
trailers, travel trailers, and other similar recreational vehicles placed on a site for greater than 180 consecutive
days. For insurance purposes, theThe term “manufactured home” does not include park trailers, travel trailers,
and other similar a “recreational vehicles.vehicle.”
EE.HH. W. “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.
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II. X. “Market value” shall mean the current assessed value as established by the most recent tax roll of
the county assessor in which the property is located. An applicant may, at applicant’s expense, provide an
appraisal to determine market value.
FF.JJ. “Mean Sea Level” means for purposes of the National Flood Insurance Program, the vertical datum to
which Base Flood Elevations shown on a community's Flood Insurance Rate Map are referenced.
GG.KK. Y. “Native vegetation” means plant species that are indigenous to the community’s area and that
reasonably could be expected to naturally occur on the site.
HH.LL. Z. “Natural floodplain functions” means the contribution that a floodplain makes to support habitat,
including, but not limited to, providing flood storage and conveyance, reducing flood velocities, reducing
sedimentation, filtering nutrients and impurities from runoff, processing organic wastes, moderating
temperature fluctuations, and providing breeding and feeding grounds, shelter, and refugia, for aquatic or
riparian species.
II.MM. AA. “New construction” means for the purposes of determining insurance rates, structures for which
the “start of construction” commenced on or after the effective date of an initial Flood Insurance Rate Map or
after December 31, 1974, whichever is later, and includes any subsequent improvements to such structures.
For floodplain management purposes, “new construction” means structures for which the “start of construction”
commenced on or after the effective date of the ordinance adopted by a community and includes any
subsequent improvements to such structurescodified in this chapter.
NN. BB. “Principal Structure” means a structure in which the principal use of the lot on which it is located is
conducted.
JJ.OO. “Protected area” means the lands that lie within the boundaries of the floodway, the riparian
habitatbuffer zone, and the channel migration area. In riverine areas, where a floodway has not been
designated in accordance with this chapter, the protected area is comprised of those lands that lie within the
boundariesBecause of the riparian habitat zone, the channel migration area, and the SFHAimpact that
development can have on flood heights and velocities and habitat, special rules apply in the Protected Area.
PP. CC. “Reasonably Safe from Flooding” means development that is designed and built to be safe from
flooding based on consideration of current flood elevation studies, historical data, high water marks and other
reliable data known to the community. In unnumbered A zones where flood elevation information is not
available and cannot be obtained by practicable means, reasonably safe from flooding means that the lowest
floor is at least two feet above the Highest Adjacent Grade.
KK.QQ. “Recreational vehicle” means a vehicle:
1. . . Built on a single chassis; and,
2. . . Four hundred square feet or less when measured at the largest horizontal projection; and,
3. . . Designed to be self-propelled or permanently towable by a an automobile or light-duty
truck; and,
4. . . Designed primarily not for use as a permanent dwelling but as temporary living quarters
for recreationrecreational, camping, travel, or seasonal use.
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LL. DD. “Regulatory floodplain” means the area of the special flood hazard area and all protected areas
within the city of Auburn. It also includes newly designated special flood hazard areas and protected areas that
are delineated pursuant to city law.
MM.RR. EE. “Riparian” means of, adjacent to, or living on, the bank of a stream, lake, pond, sound, or other
water body.
SS. FF. “Riparian habitat zone“Riparian buffer zone” means the land located adjacent to streams, and
other bodies of water, where the natural soil, hydrology, and native flora and fauna perform important
ecological functions such as protecting the water body by filtering out pollutants, preventing erosion and
sedimentation, stabilizing stream banks, and providing natural shade. They are often thin lines-of-green
containing native grasses, flowers, shrubs and trees that line the banks of streams and other bodies of water.
The riparian buffer zone for the Puget Sound Biological Opinion applies only to areas mapped within the
Special Flood Hazard Area, unless the area is undeveloped with predominately native vegetation that have
benefits to endangered species, in which case the regulations for riparian habitat zones shall apply.
NN.TT. ”Riparian Habitat Zone” means the water body and adjacent land areas that are likely to support
aquatic and riparian habitat as detailed in this chapter. The size and location of the riparian habitat zone is
dependent on the type of water body. The riparian habitat zone includes the water body and adjacent lands,
measured perpendicularly from ordinary high water on both sides of the water body:.
OO. 1. Marine and lake shorelines and Type S streams that are designated “shorelines of the state”: 250
feet.
PP. 2. Type F (fish bearing) streams greater than five feet wide and marine shorelines: 200 feet.
QQ. 3. Type F streams less than five feet wide and lakes: 150 feet.
RR. 4. Type N (nonsalmonid-bearing) perennial and seasonal streams with unstable slopes: 225 feet.
SS. 5. All other Type N (nonsalmonid-bearing) perennial and seasonal streams: 150 feet.
TT. In addition, the riparian habitat zone may include additional land areas that the floodplain administrator
determines are likely to support aquatic and riparian habitat.
UU. GG. “Special flood hazard area (SFHA)” means the land subject to inundation by the base flood.
Special flood hazard areas are identified by the Federal Emergency Management Agency in the scientific and
engineering reports entitled “Flood Insurance Study for King County, Washington and Incorporated Areas,”
dated April 19, 2005, and any revisions thereto, and “Flood Insurance Study for Pierce County, Washington
and Unincorporated Areas,” dated August 19, 1987, and any revisions thereto, and designated on associated
flood insurance rate maps with the letter A, including AE, AO, AH, A1 – 99.designated on Flood Insurance Rate
Maps with the letters “A” or “V” include AE (floodway), AO, AH, A1-99 and VE. The Special Flood Hazard Area
is also referred to as the area of special flood hazard or SFHA.
VV. HH. “Start of construction” includes substantial improvement, and means the date the building permit
was issued, provided the actual start of construction, repair, reconstruction, rehabilitation, addition, placement
or other improvement that occurred beforewas within 180 days of the permit’s expiration date of the permit.
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
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not include land preparation, such as clearing, grading and filling; nor does it include the installation of streets
and/or walkways; nor does it include excavation for a basement, footings, piers, or foundations or the erection
of temporary forms; nor does it include the installation on the property of accessory buildings, such as garages
or sheds not occupied as dwelling units or not part of the main structure. For a substantial improvement, the
“actual “start of construction” means the first alteration of any wall, ceiling, floor, or other structural part of a
building, whether or not that alteration affects the external dimensions of the building.
WW. II. “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.
XX. JJ. “Substantial damage” means damage of any origin sustained by a structure whereby the cost of
restoring the structure to its before-damaged condition would equal or exceed 50 percent of the market value of
the structure before the damage occurred.
YY. KK. “Substantial improvement” or “substantially improved” means any repair, reconstruction,
rehabilitation, addition, replacement or improvement of a structure, the cost of which equals or exceeds 50
percent of the market value of such structure before the start of construction of the improvement. This term
includes structures that have incurred substantial damage, regardless of the actual repair work donemarket
value of the structure before the “start of construction” of the improvement. This term includes structures which
have incurred "substantial damage," regardless of the actual repair work performed.
The term does not, however, include either:
1. . . Any project for improvement of a structure to correct existing violations of state or local
health, sanitary, or safety code specifications that have been identified by the local code enforcement
official and that are the minimum necessary to assure safe living conditions; or
2. . . Any alteration of a “historic structure” provided that the alteration will not preclude the
structure’s continued designation as a “historic structure”. listed on the National Register of Historic
Places or a State Inventory of Historic Places.
ZZ. LL. “Variance” means a grant of relief from the requirements of this chapterordinance which permits
construction in a manner that would otherwise be prohibited by this chapterordinance.
AAA. MM. “Violation” means the failure of a structure or other development to be constructed or
implemented in conformance with the community’s applicable floodplain development regulations.
AAA.BBB. “Water typing” means a system for classifying water bodies according to their size and fish
habitat characteristics. The Washington Department of Natural Resources Forest Practices Water Typing
Classification System is hereby adopted by reference. The system defines four water types:
1. . . Type “S” – Shoreline: Streams that are designated “shorelines of the state,” including
marine shorelines.
2. . . Type “F” – Fish: Streams that are known to be used by fish or meet the physical criteria to
be potentially used by fish.
3. . . Type “NP” Np” – Non-fish perennial streams.
4. . . Type “NS” Ns” – Non-fish seasonal streams.
BBB.CCC. NN. “Zone” means one or more areas delineated on the FIRM. The following zones may be
used on the adopted FIRM. The special flood hazard area is comprised of the A Zone.and V Zones.
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1. . . A: SFHA where no base flood elevation is provided.
2. . . A#: Numbered A zones (e.g., A7 or A14), SFHA with a base flood elevation.
3. . . AE: SFHA with a base flood elevation.
4. . . AO: SFHA subject to inundation by shallow flooding usually resulting from sheet flow on
sloping terrain, with average depths between one and three feet. Average flood depths are shown.
5. . . AH: SFHA subject to inundation by shallow flooding (usually areas of ponding) with
average depths between one and three feet. Base flood elevations are shown.
6. . . B: The area between the SFHA and the 500-year flood of the primary source of flooding. It
may also be an area with a local, shallow flooding problem or an area protected by a levee.
7. . . C: An area of minimal flood hazard, as above the 500-year flood level of the primary
source of flooding. B and C zones may have flooding that does not meet the criteria to be mapped as a
special flood hazard area, especially ponding and local drainage problems.
8. . . D: Area of undetermined but possible flood hazard.
9. . . X: The area outside the mapped SFHA.
10. . . Shaded X: The same as a Zone B, in subsection (NN)(6) of this section.above.
Article III. General Provisions
Section 3. Regulatory Data
15.68.070 Land110 Area to which this chapter appliesbe Regulated.
This chapter shall apply to the regulatory floodplain The area to be regulated is comprised of the Special Flood
Hazard Area and all Protected Areas within the Special Flood Hazard Area within the jurisdiction of the city.
(See the cityCity of Auburn regulatory floodplain map on file in the office of the city clerk.) . The term also
includes areas delineated pursuant to the provisions of Chapter 1.25 ACC. Section 15.68.150.
.15.68.120 Special Flood Hazard Area.
Basis for Establishing the Areas of Special Flood Hazard
A. The special flood hazard areas identified by the Federal Insurance Administrator in a scientific and
engineering report entitled “The Flood Insurance Study (FIS) for King County Washington and Incorporated
Areas” dated August 19, 2020, and any revisions thereto, with accompanying Flood Insurance Rate Maps
(FIRMs) dated August 19, 2020, and any revisions thereto, as well as the special flood hazard areas identified
by the Federal Insurance Administrator in a scientific and engineering report entitled “The Flood Insurance
Study (FIS) for Pierce County Washington and Incorporated Areas” dated March 7, 2017, and any revisions
thereto, with accompanying Flood Insurance Rate Maps (FIRMs) dated March 7, 2017, and any revisions
thereto, are hereby adopted by reference and declared to be a part of this ordinance. The FIS and the FIRM
are on file at 1 East Main St, Auburn, WA 98001.
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A.B. The best available information for flood hazard area identification as outlined in Section 15.68.130(D)
shall be the basis for regulation until a new FIRM is issued that incorporates data utilized under Section
15.68.130(D).
B. 15.68.110 Interpretation.
C. In Upon receipt of a floodplain development permit application, the floodplain administrator or designee
shall compare the elevation of the site to the base flood elevation.
C.D. The floodplain administrator or designee shall inform the applicant that the project may still be subject
to the flood insurance purchase requirements unless the owner receives a Letter of Map Amendment (LOMA)
from FEMA.
E. The floodplain administrator or designee shall make interpretations where needed, as to the exact
locations of the boundaries of the SFHA and the Protected Area (e.g. where there appears to be a conflict
between the mapped SFHA boundary and actual field conditions as determined by the base flood elevation and
ground elevations) as it applies to proposed development. The applicant may appeal the floodplain
administrator’s or designee’s interpretation and application of this chapter,of the location of the boundary to the
Hearing Examiner for the City of Auburn.
15.68.130 Flood Hazard Data.
A. The base flood elevation for the SFHAs incorporated in 15.68.120(A) shall be utilized.
B. The Flood Protection Elevation (FPE) shall be the base flood elevation plus one (1) foot.
C. The floodway shall be as delineated on the Flood Insurance Rate Map.
D. Where base flood elevation and floodway data have not been provided in Special Flood Hazard Areas,
the floodplain administrator or designee shall obtain, review and reasonably utilize any base flood elevation and
floodway data available from a Federal, State or other source.
15.68.140 Protected Area.
A. The Protected Area is comprised of those lands that lie within the boundaries of the floodway, the
riparian habitat buffer zone, and the channel migration area.
B. In riverine areas, where a floodway has been designated in accordance with Sections 15.68.130.(C),
15.68.130(.D) or 15.68.150(.E), the Protected Area is comprised of those lands that lie within the boundaries of
the riparian habitat buffer zone, the channel migration area, and the SFHA.
C. Riparian Buffer Zone: The riparian buffer zone includes those watercourses within the SFHA and
adjacent land areas that are likely to support aquatic and riparian habitat.
1. The size and location of the riparian buffer zone is dependent on the type of water body. The
riparian buffer zone includes the water body and adjacent lands, measured perpendicularly from
ordinary high water mark on both sides of the water body:
a. Type S streams that are designated “shorelines of the State:” 250 feet
b. Type F streams (fish bearing) streams greater than 5 feet wide and marine
shorelines: 200 feet
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c. Type F streams less than 5 feet wide and lakes: 150 feet
d. Type N (nonsalmonid-bearing) perennial and seasonal streams with unstable slopes:
225 feet
e. All other Type N (nonsalmonid-bearing) perennial and seasonal streams: 150 feet.
2. The riparian buffer zone shall be delineated on the site plan by the applicant at the time of
application for subdivision approval or floodplain development permit for all development proposals
within 300 feet of any stream or shoreline.
D. Channel Migration Area:
a. The channel migration area shall be the channel migration zone as defined in Section
15.68.100(K).
b. Where more than one channel migration zone has been delineated, the floodplain
administrator or designee shall use the delineation that has been adopted for other local
regulatory purposes.
a.c. Where a channel migration zone has not yet been mapped, the provisions shall be:of
Section 15.68.150.(D) shall apply at the time of permit application.
15.68.150 New Regulatory Data.
A. All requests to revise or change the flood hazard data, including requests for a Letter of Map Revision
and a Conditional Letter of Map Revision shall be reviewed by the floodplain administrator or designee.
1. The floodplain administrator or designee shall not sign the Community Acknowledgment Form
for any requests based on filling or other development, unless the applicant for the letter documents
that such filling or development is in compliance with this ordinance.
2. The floodplain administrator or designee shall not approve a request to revise or change a
floodway delineation until FEMA has issued a Conditional Letter of Map Revision that approves the
change.
B. If an applicant disagrees with the regulatory data prescribed by this ordinance, he/she may submit a
detailed technical study needed to replace existing data with better data in accordance with FEMA mapping
guidelines or Regional Guidance for Hydrologic and Hydraulic Studies in Support of the Model Ordinance for
Floodplain Management under the National Flood Insurance Program and Endangered Species Act FEMA
Region X, 2010. If the data in question are shown on the published FIRM, the submittal must also include a
request to FEMA for a Conditional Letter of Map Revision.
C. Where base flood elevation data are not available in accordance with Section 15.68.130, applicants for
approval of new subdivisions and other proposed developments (including proposals for manufactured home
parks) greater than 50 lots or 5 acres, whichever is the lesser, shall include such data with their permit
applications.
D. Where channel migration zone data are not available in accordance with 15.68.140(D), the permit
applicant shall either:
1. Designate the entire SFHA as the channel migration zone or
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2. Identify the channel migration area in accordance with Regional Guidance for Hydrologic and
Hydraulic Studies in Support of the Model Ordinance for Floodplain Management under the National
Flood Insurance Program and Endangered Species Act FEMA Region X, 2012.
E. All new hydrologic and hydraulic flood studies conducted pursuant to Section 15.68.150 shall be in
accordance with Regional Guidance for Hydrologic and Hydraulic Studies in Support of the Model Ordinance
for Floodplain Management under the National Flood Insurance Program and the Endangered Species Act,
FEMA, Region X, 2010.
F. The floodplain administrator shall use the most restrictive data available prepared specifically for the
project site for the channel migration zone, floodways, future conditions, and riparian buffer zone.
Section 4. Administration
15.68.160 Establishment of Floodplain Development Permit
A floodplain development permit shall be obtained before construction or development begins within the
Special Flood Hazard Area (SFHA) or Protected Area. The permit shall be for all development as set forth in
15.68.170 Floodplain Development Permit Application.
Applications for a floodplain development permit shall be made using the criteria outlined in the Floodplain
Development Application Packet available for download at www.auburnwa.gov/forms. At a minimum, the
following information is required.
A. Elevation in relation to mean sea level, of the lowest floor (including basement) of all structures
recorded on a current elevation certificate with Section B completed by the Floodplain Administrator.
B. Elevation in relation to mean sea level to which any structure has been flood proofed;
C. Where a structure is to be flood proofed, certification by a registered professional engineer or architect
that the flood proofing methods for any nonresidential structure meet flood proofing criteria in Section 5;
D. Description of the extent to which a watercourse will be altered or relocated as a result of proposed
development;
E. Where development is proposed in a floodway, an engineering analysis indicating no rise of the Base
Flood Elevation; and
F. Any other such information that may be reasonably required by the Floodplain Administrator in order to
review the application.
15.68.180 Floodplain Development Permit Expiration.
If there has been no start of construction, a floodplain development permit shall expire 180 days after the date
of issuance. Where the applicant documents a need for an extension beyond this period due to conditions
beyond the applicant’s control, the floodplain administrator A. or designee may authorize one or more
extensions.
15.68.190 Designation of the Floodplain Administrator.
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The Director of Community Development is hereby appointed to administer, interpret, and implement this
ordinance by granting or denying floodplain development permit applications in accordance with its provision.
The Director of Community Development may designate administration of portions or all of this ordinance to a
qualified person.
15.68.200 Duties of the Floodplain Administrator.
Duties of the floodplain administrator or designee shall include, but are not limited to:
A. Review all floodplain development permits to determine that the permit requirements of this ordinance
have been satisfied.
B. Review all floodplain development permits to determine that all necessary permits have been obtained
from those Federal, State or local government agencies from which prior approval is required, including those
local, State or Federal permits that may be required to assure compliance with the Endangered Species Act
and/or other appropriate State or Federal laws.
C. Review all floodplain development permits to determine if the proposed development is located in the
Protected Area. If located in the Protected Area, ensure that the provisions of Section 7 are met.
D. Ensure that all development activities within the Special Flood Hazard Area of the jurisdiction of the
City meet the requirements of the ordinance.
E. Inspect all development projects before, during and after construction to ensure compliance with all
provisions of this ordinance, including proper elevation of the structure.
F. Maintain for public inspection all records pertaining to the provisions of this ordinance.
G. Submit reports to include the projects for which they issue floodplain development permits, including
effects to flood storage, fish habitat, and all indirect effects of development and mitigation provided to FEMA as
required by the National Flood Insurance Program.
H. Notify FEMA of any proposed amendments to this ordinance and when annexations occur in the
Special Flood Hazard Area.
I. Ensure the proposed development is not located in the floodway. If located in the floodway, assure the
encroachment provisions of Section 15.68.410 are met
J. Cooperate with State and Federal agencies to improve flood and other technical data and notify FEMA
of any new data that would revise the FIRM.
K. Review all floodplain development permits to verify that proposed development will be reasonably safe
from flooding.
15.68.210 Notification to Other Entities
Whenever a watercourse is to be altered or relocated:
A. Notify adjacent communities and the Department of Ecology prior to such alteration or relocation of a
watercourse, and submit evidence of such notification to the Federal Insurance Administrator through
appropriate notification means, and
B. Assure that the flood carrying capacity of the altered or relocated portion of said watercourse is
maintained.
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15.68.220 Records.
A. Where base flood elevation data have been obtained pursuant to Section 15.68.130 and 15.68.150,
the floodplain administrator or designee shall obtain, record, and maintain the actual “finished construction”
elevations provided by the applicant for the locations listed in Section 15.68.170. This information shall be
recorded on a current FEMA Elevation Certificate signed and sealed by a professional land surveyor, currently
licensed in the State of Washington.
B. For all new or substantially improved dry floodproofed nonresidential structures, where base flood
elevation data has been obtained pursuant to Section 15.68.130 and 15.68.150, the floodplain administrator or
designee shall obtain, record and maintain the elevation (in relation to the datum of the effective FIRM) to
which the structure was floodproofed. This information shall be recorded on a current FEMA Floodproofing
Certificate by a professional engineer currently licensed in the State of Washington.
C. Certification required by Section 15.68.410 (floodway encroachments).
D. Records of all variance actions, including justification for their issuance.
E. Improvement and damage calculations.
F. Maintain for public inspection all records pertaining to the provisions of this ordinance.
15.68.230 Certificate of Occupancy.
A. A final grading and/or storm permit for the property, physical completion for City of Auburn Capital
Improvement projects without a building, a certificate of occupancy (commercial building) or final building
inspection (residential structure) for a new or substantially improved structure or an addition shall not be issued
until:
1. The permit applicant provides a properly completed, signed and sealed Elevation or
Floodproofing Certificate showing finished construction data as required by Section 15.68.220;
2. If a mitigation plan is required by Sections 15.68.440 and 15.68.450, all work identified in the
plan has been completed according to the plan’s schedule;
3. The applicant provides copies of all required Federal, State, and local permits noted in the
permit application per Section 15.68.170;
4. All other provisions of this ordinance and conditions placed on the floodplain development
permit approval letter have been met.
15.68.240 B. Liberally construed in favor of the governing body;
C. D. Maps referred to in this chapter are for reference only, unless specified. If the map does not specifically
indicate that it is the primary source of regulation, the text of the applicable code section shall control over any
contrary information provided on a map. (Ord. 6295 § 2, 2010; Ord. 6161 § 1, 2008; Ord. 4820 § 1, 1995; Ord.
4357 § 2 (3.5), 1989.)
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15.68.120 Warning and disclaimer of liability.
The degree of property and habitat protection required by this chapter is considered reasonable for regulatory
purposes and is based on scientific and engineering considerations. Larger floods and movement of channels
outside of mapped channel migration areas can and will occur on rare occasions. Flood heights may be
increased by manmade or natural causes. This chapter does not imply that land outside the areas of special
flood hazard or uses permitted within such areas will be free from flooding or flood damages. This chapter does
not imply that land outside the regulated areas or development permitted within such areas will be free from
flood or erosion damage. This chapter shall not create liability on the part of the city, any officer or employee
thereof, for any damage to property or habitat that results from reliance on this chapter or any administrative
decision lawfully made thereunder. (Ord. 6295 § 2, 2010; Ord. 6161 § 1, 2008; Ord. 4820 § 1, 1995; Ord. 4357
§ 2(3.6), 1989.)
15.68.125 Appeals.
A. The Hearing Examiner, as established by Chapter 2.46 of the Auburn City Code, shall hear and decide
appeals and requests for variances from the requirements of this chapter.ordinance.
B. The Hearing Examiner shall hear and decide appeals when it is alleged there is an error in any
requirement, decision, or determination made by the floodplain administrator or designee in the enforcement or
administration of this chapter.ordinance.
C. Those aggrieved by the decision of the Hearing Examiner may appeal suchthe decision to the superior
court. of the county in which the project is located pursuant to Section 2.46.160 of the Auburn City Code.
D. Upon consideration of the factors of this chapterSection 15.68.250 and the purposes of this
chapterordinance, the hearing examinerHearing Examiner may attach such conditions to the granting of the
variances as ithe/she deems necessary to further the purposes of this chapter. ordinance.
Article IV. Administration
E. The floodplain administrator or designee shall maintain the records of all appeal actions and report any
variances to the Federal Emergency Management Agency upon request.
15.68.130 Establishment of and requirement to obtain floodplain250 Variance Criteria.
A. In addition to the Criteria outlined in ACC 18.70.025, in reviewing applications for a variance, the
Hearing Examiner shall consider all technical evaluations, all relevant factors, standards specified in other
sections of this ordinance; and:
1. The relationship of the proposed use to the comprehensive plan, growth management
regulations, critical area regulations, the shoreline management program and floodplain management
program for the area;
1.2. The potential of the proposed development permit.project to destroy or adversely affect a fish
and wildlife habitat conservation area or create an adverse effect to federal, state or locally protected
species or habitat;
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3. A. A floodplain development permit Is the minimum necessary to grant relief; and,
B. In addition to the Criteria outlined in ACC 18.70.025, no variance shall be obtained beforegranted to
the requirements of this ordinance unless the applicant demonstrates that:
1. The project will not adversely affect features or quality of habitat supporting local, state or
federally protected fish or wildlife;
C. Variances may be requested for new construction or development begins, substantial improvements,
and other development for the conduct of functionally dependent uses provided:
1. There is good and sufficient cause for providing relief;
2. The variance is the minimum necessary to provide relief;
1.3. The variance does not cause a rise in the 100-year flood level within the regulatory floodplain.
The permit shall be for all development as defined in this chapter.floodplain;
4. The project will not adversely affect federal, state or locally protected fish, wildlife and their
habitat or the functions associated with their habitat.
D. Variances shall only be issued:
1. Upon a determination that the granting of a variance will not result in increased flood heights,
additional threats to public safety, extraordinary public expense, create nuisances, cause
fraud on or victimization of the public, or conflict with existing local laws or ordinances;
2. For the repair, rehabilitation, or restoration of historic structures upon a determination that the
proposed repair or rehabilitation will not preclude the structure’s continued designation as a
historic structure and the variance is the minimum necessary to preserve the historic character
and design of the structure;
3. Upon a determination that failure to grant the variance would result in exceptional hardship to
the applicant;
4. Upon a showing that the use cannot perform its intended purpose unless it is located or
carried out in close proximity to water. This includes only facilities defined in Section 2 of this
ordinance in the definition of “Functionally Dependent Use.”
E. Variances shall not be issued within any floodway if any increase in flood levels during the base flood
discharge would result.
F. Generally, variances may be issued for new construction and substantial improvements to be erected
on a lot of one-half acre or less in size contiguous to and surrounded by lots with existing structures
constructed below the BFE, provided the procedures of Sections 4 and 5 of this ordinance have been fully
considered. As the lot size increases beyond one-half acre, the technical justification required for issuing the
variance increases.
G. In considering variance applications, the {Governing Body} shall consider all technical evaluations, all
relevant factors, all standards specified in other sections of this ordinance, and:
1. The danger that materials may be swept onto other lands to the injury of others;
2. The danger to life and property due to flooding or erosion damage;
3. The susceptibility of the proposed facility and its contents to flood damage and the effect
of such damage on the individual owner;
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4. The importance of the services provided by the proposed facility to the community;
5. The necessity to the facility of a waterfront location, where applicable;
6. The availability of alternative locations for the proposed use, which are not subject to
flooding or erosion damage;
7. The compatibility of the proposed use with existing and anticipated development;
8. The relationship of the proposed use to the comprehensive plan and floodplain
management program for that area;
9. The safety of access to the property in time of flood for ordinary and emergency vehicles;
10. The expected heights, velocity, duration, rate of rise, and sediment transport of the
floodwaters expected at the site; and,
11. The costs of providing governmental services during and after flood conditions, including
maintenance and repair of public utilities and facilities, such as sewer, gas, electrical, water
system, and streets and bridges.
Section 5. General Development Standards
The provisions of Section 5 shall apply in the Special Flood Hazard Area:
15.68.260 Subdivisions.
This section applies to all subdivision proposals, including short subdivisions, preliminary subdivisions, binding
site plans, and expansions to manufactured home parks as defined in Chapter 17.04 ACC.
A. All proposals shall be consistent with the need to minimize flood damage.
B. The proposed subdivision must have one or more new lots in the Special Flood Hazard Area set aside
for open space use through deed restriction, easement, subdivision covenant, or donation to a public agency.
1. In the Special Flood Hazard Area outside the Protected Area, zoning must maintain a low
density of floodplain development.
2. In the Special Flood Hazard Area outside the protected area in which the current zoning is
less than 5 acres must maintain current zoning.
3. The density of development in the portion of the development outside the Special Flood
Hazard Area may be increased to compensate for the amount of land in the Special Flood Hazard
Area preserved as open space in accordance with Chapter 17.25 ACC.
C. If a parcel has a buildable site outside the Special Flood Hazard Area, it shall not be subdivided to
create a new lot that does not have a buildable site outside of the Special Flood Hazard Area. This provision
does not apply to tracts that are to be preserved as open space.
D. All proposals shall have utilities and facilities, such as sewer, gas, electrical, and water systems
located and constructed to prevent flood damage.
E. All proposals shall ensure that all subdivisions have at least one access road connected to land
outside the Special Flood Hazard Area with the surface of the road at or above the FPE wherever possible.
Additional access roads may be required based on the number of proposed lots per the current City of Auburn
Engineering Design Standards.
F. All proposals shall have adequate drainage provided to avoid exposure to water damage.
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G. The final recorded plat shall include a notice that part of the property is in the SFHA, riparian buffer
zone and/or channel migration area, as appropriate.
15.68.270 Site Design.
A. Structures and other development shall be located to avoid flood damage or that adequately mitigates
any identified impacts.
1. If a lot has a buildable site out of the Special Flood Hazard Area, all new structures shall be
located in that area, when possible.
2. If a lot does not have a buildable site out of the Special Flood Hazard Area, all new structures,
pavement, and other development must be sited in the location that has the least impact on habitat by
locating the development as far from the water body as possible or by placing the structure on the
highest portion of the lot.
3. A minimum setback of 15 feet from the Protected Area shall be required for all structures.
4. If the proposed project does not meet the criteria of Section 15.68.270(.A) through (B), a
habitat impact assessment shall be conducted pursuant to Section 15.68.440 and, if necessary, a
habitat mitigation plan shall be prepared and implemented pursuant to Section 15.68.450.
B. All new development shall be designed and located to minimize the impact on flood flows, flood
storage, water quality and habitat.
1. Stormwater and drainage features shall incorporate low impact development techniques, if
technically feasible, that mimic pre-development hydrologic conditions, such as stormwater infiltration,
rain gardens, grass swales, filter strips, disconnected hard surface areas, permeable pavement,
vegetative roof systems, etc. per the City’s current SWMM per Chapter 12.04 ACC.
2. If the proposed project will create new hard surfaces so that more than 10 percent of the
portion of the lot in the Special Flood Hazard Area is covered by hard surface, the applicant shall
demonstrate that there will be no net increase in the rate and volume of the stormwater surface runoff
per the maximum extent feasible and as required per the City’s current SWMM per ACC 13.48 that
leaves the site or that the adverse impact is mitigated, as provided in Sections 15.68.440 and
15.68.450.
C. The site plan required in Section 15.68.170 shall account for surface drainage to ensure that:
1. Existing and new buildings on the site will be protected from stormwater runoff; and
2. The project will not divert or increase surface water runoff onto neighboring properties.
15.68.280 Hazardous Materials.
A. No new development shall create a threat to public health, public safety or water quality. Chemicals,
explosives, gasoline, propane, buoyant materials, animal wastes, fertilizers, flammable liquids, pollutants, or
other materials that are hazardous, toxic, or a threat to water quality are prohibited from the Special Flood
Hazard Area. This prohibition does not apply to small quantities of these materials kept for normal household
use. This prohibition does not apply to the continued operations of existing facilities and structure, reuse of
existing facilities and structures, or functionally dependent facilities or structures.
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B. If the proposed project cannot meet Section 15.68.280(A) of this ordinance, then a habitat impact
assessment must be conducted in accordance with Sections 15.68.440 and 15.68.450.
15.68.290 Critical Facilities.
A. Construction of new critical facilities shall be, to the extent possible, located outside the limits of the
Special Flood Hazard Area.
B. Construction of new critical facilities in the Special Flood Hazard Area shall be permissible if no
feasible alternative site is available, provided;
1. Critical facilities shall have the lowest floor elevated three feet above the base flood elevation
or to the height of the 500-year flood, whichever is higher. If there is no available data on the 500-year
flood, the permit applicants shall develop the needed data in accordance with FEMA mapping
guidelines.B. A development project is not subject
1. Access to and from the requirements of this chapter if it is located on land that cancritical
facility shall be shown to be:
2. 1. Outside the protected area; and
3.2. 2. Higher thanto the elevation of the 500-year floodplain. Access routes elevated to or
above the level of the base flood elevation shall be provided to all critical facilities to the extent
possible.
Section 6. Standards for Protection of Structures
15.68.300 Applicability.
The protection requirements in this section apply to all new structures and substantial improvements, which
include:
A. Construction or placement of a new structure.
B. Reconstruction, rehabilitation, or other improvement that will result in a substantially improved building.
C. Repairs to an existing building that has been substantially damaged.
D. Placing a manufactured home on a site.
E. Placing an occupied recreational vehicle or travel trailer on a site for more than 180 days.
15.68.310 Flood Protection Standards.
A. All new structures and substantial improvements shall have the lowest floor, including basement,
elevated above the FPE.
B. New construction and substantial improvement of any residential structure in an Unnumbered A zone
for which a BFE is not available and cannot be reasonably obtained shall be reasonably safe from flooding, but
in all cases the lowest floor shall be at least two feet above the Highest Adjacent Grade.
C. The structure shall be aligned parallel with the direction of flood flows where practicable.
D. The structure shall be anchored to prevent flotation, collapse, or lateral movement of the structure
resulting from hydrodynamic and hydrostatic loads including the effects of buoyancy.
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E. All manufactured homes shall be anchored to prevent flotation, collapse, or lateral movement, and
shall be installed using methods and practices that minimize flood damage. Anchoring methods may include,
but are not limited to, use of over-the-top or frame ties to ground anchors.
F. All materials below the FPE shall be resistant to flood damage and firmly anchored to prevent flotation.
Materials harmful to aquatic wildlife, such as creosote, are prohibited below the FPE.
G. All new construction and substantial improvements shall be constructed using methods and practices
that minimize flood damage
H. Electrical, heating, ventilation, duct work, plumbing, and air-conditioning equipment and other service
facilities shall be elevated above the FPE. Water, sewage, electrical, and other utility lines (excluding storm
drainage facilities) below the FPE shall be constructed so as to minimize water from entering or accumulating
within them during conditioning of flooding.
I. Fully enclosed areas below the lowest floor that are subject to flooding shall be used only for parking,
limited storage, or building access and 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 shall either
be certified by a registered professional engineer or licensed architect in the State of Washington and/or meet
or exceed the following minimum criteria:
1. A minimum of two openings having a total net area not less than one square inch for every
square foot of enclosed area subject to the flood insurance purchaseflooding shall be provided.
2. The bottom of all openings shall be no higher than one foot above grade.
3. Openings must be equipped with screens, louvers, or other coverings or devices provided that
they permit the automatic entry and exit of floodwaters.
4. A garage attached to a residential structure, constructed with the garage floor slab below the
BFE, must be designed to allow for the automatic entry and exit of flood waters.
15.68.320 Nonresidential Construction.
New construction and substantial improvement of any commercial, industrial, or other nonresidential structure
shall meet the requirements of subsection A or B below:
A. New construction and substantial improvement of any commercial, industrial or other nonresidential
structure shall meet all of the following requirements:
1. In AE and A1-30 zones or other A zoned areas where the BFE has been determined or can
be reasonably obtained:
2. New construction and substantial improvement of any commercial, industrial, or other
nonresidential structure shall have the lowest floor, including basement, elevated one foot or more
above the BFE, or elevated as required by ASCE 24, whichever is greater. Mechanical equipment and
utilities shall be waterproofed or elevated least one foot above the BFE, or as required by ASCE 24,
whichever is greater. If located in an AO zone, the structure shall either:
a. 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
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b. 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 substantially
impermeable to the passage of water and with structural components having the capability of
resisting hydrostatic and hydrodynamic loads and effects of buoyancy. If this method is used,
compliance shall be certified by a registered professional engineer, or architect as in Section
15.68.220(B).
3. If located in an Unnumbered A zone for which a BFE is not available and cannot be
reasonably obtained, the structure shall be reasonably safe from flooding, but in all cases the lowest
floor shall be at least two feet above the Highest Adjacent Grade.
4. If buildings are constructed or substantially improved with fully enclosed areas below the
lowest floor, that are subject to flooding, the areas shall be used only for parking, limited storage, or
building access, and shall be designed to automatically equalize hydrostatic flood forces on exterior
walls by allowing for the entry and exit of floodwaters. Designs for meeting this requirement must either
be certified by a registered professional engineer or architect or must meet or exceed the following
minimum criteria:
a. Have a minimum of two openings with a total net area of not less than one square
inch for every square foot of enclosed area subject to flooding.
b. The bottom of all openings shall be no higher than one foot above grade.
c. Openings may be equipped with screens, louvers, valves, or other coverings or
devices provided that they permit the automatic entry and exit of floodwater.
d. A garage attached to a residential structure, constructed with the garage floor slab
below the BFE, must be designed to allow for the automatic entry and exit of flood waters.
5. Alternatively, a registered engineer or architect may design and certify engineered openings.
B. If the requirements of Section 15.68.320(A) are not met, then new construction and substantial
improvement of any commercial, industrial or other nonresidential structure shall meet all of the following
requirements:
1. Be dry floodproofed so that below one foot or more above the base flood level the structure is
watertight with walls substantially impermeable to the passage of water or dry floodproofed to the
elevation required by ASCE 24, whichever is greater;
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 the structural design, specifications and
plans. Such certifications shall be provided to the official as set forth in Section 15.68.220(B);
4. Nonresidential structures that are elevated, not floodproofed, must meet the same standards
for space below the lowest floor as described in 15.68.320(A)(2);
15.68.330 Manufactured Homes.
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All manufactured homes to be placed or substantially improved on sites shall be:
A. Elevated on a permanent foundation in accordance with Section 15.68.310(A) and
B. Securely anchored to an adequately anchored foundation system to resist flotation, collapse and
lateral movement. Methods of anchoring may include, but are not to be limited to, use of over-the-top or frame
ties to ground anchors. This requirement is in addition to other applicable anchoring requirements for resisting
wind forces.
C. If manufactured homes are constructed or substantially improved with fully enclosed areas below
the lowest floor, the areas shall be used solely for parking of vehicles, building access, or storage.
15.68.340 Recreational Vehicles.
Recreational vehicles placed on sites shall:
A. Be on the site for fewer than 180 consecutive days, or
B. Be fully licensed and ready for highway use, on their wheels or jacking system, attached to the site
only by quick disconnect type utilities and security devices, and have no permanently attached addition; or
C. Meet the requirements of Section 15.68.340 and the anchoring requirements for manufactured homes
in Section 15.68.330.
15.68.350 Appurtenant Structures.
A structure which is on the same parcel of property as the principle structure and the use of which is incidental
to the use of the principle structure and is not used for human habitation may be exempt from the elevation
requirements of Section 15.68.310.(A), provided:
A. It is used only for parking or storage;
B. It is constructed and placed on the building site so as to offer minimum resistance to the flow of
floodwaters;
C. It is anchored to prevent flotation which may result in damage to other structures;
D. C. NondevelopmentAll portions of the structure below the FPE must be constructed of flood-resistant
materials;
E. Service utilities such as electrical and heating equipment meet the standards of Section 15.68.310(F)
and Section 15.68.360;
F. It has openings to allow free flowage of water that meet the criteria in Section 15.68.310(I);
G. The project meets all the other requirements of this ordinance, including Section 7.
15.68.360 Utilities.
A. All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of
flood waters into the system;
B. New water wells shall be located outside the floodway and shall be protected to the FPE;
C. New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration
of flood waters into the systems and discharges from the systems into the floodwaters;
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D. Onsite waste disposal systems shall be located to avoid impairment to them or contamination from
them during flooding. A habitat impact assessment shall be conducted in accordance with Section 15.68.440 as
a condition of approval of an onsite waste disposal system to be located in the Special Flood Hazard Area.
Section 7. Standards for Habitat Protection
The provisions of this Section shall apply in the Special Flood Hazard Area and channel migration zone.
15.68.370 Non-Development Activities.
Activities that do not meet the definition of “development” in this chapter are allowed in the regulatory
floodplainSpecial Flood Hazard Area and Protected Area without the need for a floodplain development permit
under this chapterordinance, provided all other federal, state,Federal, State and local requirements are met.
The following are examples of activities not considered development or manmade“unnatural changes to
improved or unimproved real estate:”.
A. 1. Routine maintenance of landscaping that does not involve grading, excavation, or filling;
B. 2. Removal of noxious weeds and hazard trees and replacement of nonnativenon-native vegetation
with native vegetation;
C. 3. Normal maintenance of structures, such as re-roofing and replacing siding, as long asprovided
such work does not qualify as a substantial improvement;
D. 4. Normal maintenance of above ground public utilities and facilities, such as replacing downed
power lines and utility poles;
E. 5. Underground and above ground utility work located in previously disturbed areas, with no
significant vegetation impacts, and will have no appreciable change in grade;
E.F. Normal street and road maintenance and preservation of public streets and private streets or parking
lots (with approval of Floodplain Administrator) , including, but not limited to filling potholes, patching, crack
seal, chip seal, repaving, and installing signs and traffic signalssigns, traffic control devices,
striping/channelization, pavement markings, repair/replacement of sidewalk/curb and gutter, ADA
improvements, non-motorized improvements, repair of guardrails, repair of retaining walls, management of
hazardous trees, fencing repair, lighting repair, but not including expansion of paved areas;
G. 6. Public street improvements with no significant vegetation impacts, and no appreciable change in
grade;
F.H. Normal maintenance of a levee or other flood control facility prescribed in the operations and
maintenance plan for the levee or flood control facility are allowed in the Special Flood Hazard Area without the
need for a floodplain development permit. Normal maintenance does not include repair from flood damage,
expansion of the prism, expansion of the face or the toe or addition for protection on the face or toe with rock
armor; and
G.I. 7. Plowing and other normal farmflood protection practices (other than structures or filling) on farms in
the Special Flood Hazard Area and in existence as of the effective date of thethis ordinance codified in this
chapter.do not require a floodplain development permit. Clearing additional land for agriculture after the date of
this ordinance will require a floodplain development permit and a Habitat Assessment.
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D. 15.68.380 Activities Allowed with a Floodplain Development Permit.
The following activities are allowed in the regulatory floodplainSpecial Flood Hazard Area without the analysis
required in ACC 15.68.160(C)Section 15.68.410 or the habitat impact assessment required under ACC
15.68.135(J), providing Section 15.68.440, provided that all other requirements of this chapterordinance are
met, including obtaining a floodplain development permit:
A. 1. Repairs or remodeling of an existing structure;, provided, that the repairs or remodeling are not a
substantial improvement or a repair of substantial damage; provided further, that no habitat impact assessment
shall be required if the repair or remodel does not expand the existing building envelope.
B. 2. Expansion or reconstruction of an existing structure that is no greater than 10ten percent beyond
its existing footprint;, provided, that the repairs or remodeling are not a substantial improvement or a repair of
substantial damage. This measurement is counted cumulatively from the effective date of the ordinance
codified in this chapter. If the structure is in the floodway, there shall be no change in the structure’s
dimensions perpendicular to flow.
C. 3. Activities with the sole purpose of creating, restoring or enhancing natural functions associated
with floodplains, streams, lakes, estuaries, marine areas, habitat, and riparian areas that meet federalFederal
and stateState standards, provided the activities do not include structures, grading, fill, or impervioushard
surfaces.
D. 4. Development of open space and recreational facilities, such as parks, trails, and hunting grounds,
that do not include structures, grading, fill, impervioushard surfaces or removal of more than five percent of the
native vegetation on that portion of the property in the regulatory floodplainSpecial Flood Hazard Area.
E. E. Repairs to onsite Septic Systems provided the ground disturbance is the minimum necessary and
best management practices (BMP’s) to prevent stormwater runoff and soil erosion are used.
15.68.390 Other Activities.
All other activities not listed in subsection CSections 15.68.370 or D of this section are 15.68.380 that are
allowed, as long as by Title 18 (Zoning) of the Auburn City Code are allowed, provided they meet all the other
requirements of this chapterordinance, including the analysis required in ACC 15.68.160under Section
15.68.420, 15.68.430, and the habitat impact assessment and any mitigation required under ACC 15.68.135(K)
and (L)Section 15.68.440, and a floodplain development permit is issued.
15.68.400 Native Vegetation.
The site plan required in the Floodplain Development Application Packet shall show existing native vegetation.
A. Within the riparian buffer zone, native vegetation shall be left undisturbed, except as provided in
Sections 15.68.370 and 15.68.380(C).
B. Outside the riparian buffer zone, removal of native vegetation shall not exceed 35 percent of the
surface area of the portion of the site in the Special Flood Hazard Area. Native vegetation in the riparian buffer
zone portion of the property can be counted toward this requirement.
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C. If the proposed project does not meet the criteria of Sections 15.68.400(A) and (B), a habitat impact
assessment shall be conducted pursuant to Section 15.68.440 and, if necessary, a habitat mitigation plan shall
be prepared and implemented pursuant to Section 15.68.450.
15.68.410 Floodway Standards.
A. In addition to the other requirements of this ordinance, a project to develop in the floodway as
delineated pursuant to Sections 15.68.130(C), 15.68.130(D) or 15.68.150(E) shall meet the following criteria:
1. The applicant shall provide a certification by a registered professional engineer licensed in the
State of Washington demonstrating through hydrologic and hydraulic analyses performed in
accordance with standard engineering practices that the proposed development would 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 the following. The following exceptions must still meet all other requirements in
the ordinance, including Section 15.68.410.(A)(.1).
a. Repairs, reconstruction, or improvements to a residential structure that do not
increase the ground floor area, providing the cost of which does not exceed 50 percent of the
market value of the structure either, (1) before the repair, or reconstruction is started, or (2) if
the structure has been damaged, and is being restored, before the damage occurred. Any
project for improvement of a structure to correct existing violations of State or local health,
sanitary, or safety code specifications that have been identified by a local code enforcement
official, and which are the minimum necessary to assure safe living conditions, or to an
historic structure, may be excluded from the 50 percent calculation;
b. Repairs, reconstruction, replacement, or improvements to existing farmhouse
structures located in designated floodways and that are located on lands designated as
agricultural lands of long-term commercial significance under RCW 36.70A.170 may be
permitted subject to the following:
i. The new farmhouse is a replacement for an existing farmhouse on the same
farm site;
ii. There is no potential building site for a replacement farmhouse on the same
farm outside the designated floodway;
iii. Repairs, reconstruction, or improvements to a farmhouse shall not increase
the total square footage of encroachment of the existing farmhouse;
iv. A replacement farmhouse shall not exceed the total square footage of
encroachment of the farmhouse it is replacing;
v. A farmhouse being replaced shall be removed, in its entirety, including
foundation, from the floodway within ninety days after occupancy of a new farmhouse;
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vi. For substantial improvements and replacement farmhouses, the elevation of
the lowest floor of the improvement and farmhouse respectively, including basement,
is a minimum of one foot higher than the BFE;
vii. New and replacement water supply systems are designed to eliminate or
minimize infiltration of floodwaters into the system;
viii. New and replacement sanitary sewerage systems are designed and located
to eliminate or minimize infiltration of floodwater into the system and discharge from
the system into the floodwaters; and
ix. All other utilities and connections to public utilities are designed, constructed,
and located to eliminate or minimize flood damage.
c. For all substantially damaged residential structures, other than farmhouses, located
in a designated floodway, the Floodplain Administrator may make a written request that the
Department of Ecology assess the risk of harm to life and property posed by the specific
conditions of the floodway. Based on analysis of depth, velocity, flood-related erosion,
channel migration, debris load potential, and flood warning capability, the Department of
Ecology may exercise best professional judgment in recommending to the local permitting
authority repair, replacement, or relocation of a substantially damaged structure consistent
with WAC 173-158-076. The property owner shall be responsible for submitting to the local
government and the Department of Ecology any information necessary to complete the
assessment. Without a favorable recommendation from the department for the repair or
replacement of a substantially damaged residential structure located in the regulatory
floodway, no repair or replacement is allowed per WAC 173-158-070(1).
d. Before the repair, replacement, or reconstruction is started, all requirements of the
NFIP, the state requirements adopted pursuant to 86.16 RCW, and all applicable local
regulations must be satisfied. In addition, the following conditions must be met:
i. There is no potential safe building location for the replacement
residential structure on the same property outside the regulatory floodway.
ii. A replacement residential structure is a residential structure built as a
substitute for a legally existing residential structure of equivalent use and size.
iii. Repairs, reconstruction, or replacement of a residential structure shall
not increase the total square footage of floodway encroachment.
iv. The elevation of the lowest floor of the substantially damaged or
replacement residential structure is a minimum of one foot higher than the BFE.
v. New and replacement water supply systems are designed to eliminate or
minimize infiltration of floodwater into the system.
vi. New and replacement sanitary sewerage systems are designed and
located to eliminate or minimize infiltration of floodwater into the system and
discharge from the system into the floodwaters.
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vii. All other utilities and connections to public utilities are designed,
constructed, and located to eliminate or minimize flood damage.
e. Repairs, reconstruction, or improvements to residential structures identified as
historic structures that do not increase the building’s dimensions.
B. In riverine Special Flood Hazard Areas where a floodway has not been delineated pursuant to
Sections 15.68.130(C), 15.68.130(D) or 15.68.150(E), the applicant for a project to develop in the SFHA shall
provide a certification by a registered professional engineer in the State of Washington demonstrating through
hydrologic and hydraulic analyses performed in accordance with standard engineering practices that the
proposed development and all other past or future similar developments would not cumulatively result in an
increase of flood levels during the occurrence of the base flood discharge by more than one-half foot.
15.68.420 Standards for Shallow Flooding Areas (AO Zones)
Shallow flooding areas appear on FIRMs as AO zones with depth designations. The base flood depths in these
zones range from 1 to 3 feet above ground where a clearly defined channel does not exist, or where the path of
flooding is unpredictable and where velocity flow may be evident. Such flooding is usually characterized as
sheet flow. In addition to other provisions in this code, the following additional provisions also apply in AO
zones.
A. New construction and substantial improvements of residential structures and manufactured homes
within AO zones shall have the lowest floor (including basement and mechanical equipment) elevated above
the highest adjacent grade to the structure, one foot or more above the depth number specified in feet on the
community’s FIRM (at least two feet above the highest adjacent grade to the structure if no depth number is
specified).
B. New construction and substantial improvements of nonresidential structures within AO zones shall
either:
1. 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
2. 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 substantially
impermeable to the passage of water and with structural components having the capability of
resisting hydrostatic and hydrodynamic loads and effects of buoyancy. If this method is used,
compliance shall be certified by a registered professional engineer, or architect as in Section
15.68.310(I).
C. Require adequate drainage paths around structures on slopes to guide floodwaters around and away
from proposed structures.
D. Recreational vehicles placed on sites within AO zones on the community’s FIRM either:
1. Be on the site for fewer than 180 consecutive days, or
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2. 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
3. Meet the requirements of subsections (1) and (3) above and the anchoring requirements for
manufactured homes (Section 15.68.330(B)).
15.68.430 Compensatory Storage.
New development shall not reduce the effective flood storage volume of the Special Flood Hazard Area. A
development proposal shall provide compensatory storage if grading or other activity eliminates any effective
flood storage volume. Compensatory storage shall:
15.68.135 Floodplain development permit application.
Application for a floodplain development permit shall be made on forms furnished by the floodplain
administrator and shall include, but not be limited to:
A. One or more site plans, drawn to scale, showing:
1. The nature, location, dimensions, and Provide equivalent volumes at equivalent elevations of the property
in question;
2. Names and location of all lakes,to that being displaced. For this purpose, “equivalent elevation” means
having similar relationship to ordinary high water bodies, waterwaysmark and drainage facilities within 300 feet
ofto the site;
3. The elevations of the 10-, 50-, 100-, and 500-year floods, where the data arebest available. Additionally, for
property located within the SFHA, base flood elevations shall be included as required in ACC 15.68.060(C)(3);
4. The boundaries of the regulatory floodplain, SFHA, floodway, riparian habitat zone, and channel migration
area, delineated in accordance with this chapter;
5. The proposed drainage system including, but not limited to, storm sewers, overland flow paths, detention
facilities and roads;
6. Existing and proposed structures, fill, pavement and other impervious surfaces, and sites for storage of
materials;
7. All wetlands;
8. Designated fish and wildlife habitat conservation areas; and
9. Existing native vegetation and proposed revegetation (see ACC 15.68.161(D)).
B. If the proposed project involves regrading, excavation, or filling, the site plan shall include proposed post-
development terrain at one-foot contour intervals.
C. If the proposed project includes a new structure, substantial improvement, or repairs to a substantially
damaged structure that will be elevated, the application shall include the FPE for the building site 10-year, 50-
year and the proposed elevations of the following:
1. The top of bottom floor (including basement, crawlspace, or enclosure floor);
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2. The top of the next higher floor;
3. The top of the slab of an attached garage;
4. The lowest elevation of machinery or equipment servicing the structure;
5. The lowest adjacent (finished) grade next to structure;
6. The highest adjacent (finished) grade next to structure;
7. The lowest adjacent grade at the lowest elevation of a deck or stairs, including structural support.
D. If the proposed project includes a new structure, substantial improvement, or repairs to a substantially
damaged nonresidential structure that will be dry floodproofed, the application shall include the FPE for the
building site and the elevation in relation to the datum of the effective FIRM to which the structure will be dry
floodproofed and a certification by a registered professional engineer or licensed architect that the dry
floodproofing methods meet the floodproofing criteria in this chapter.
A. E. The application shall include a description of the extent to which a stream, lake, or other 100-year
water body, including its shoreline, will be altered or relocated as a result of the proposed developmentsurface
profiles.
B. Be hydraulically connected to the source of flooding.
C. Provide compensatory storage in the same construction season as when the displacement of flood
storage volume occurs and before the flood season begins.
D. The newly created storage area shall be graded and vegetated to allow fish access during flood events
without creating fish stranding sites.
F. The application shall include documentation that the applicant will apply for all necessary permits required
by federal, state, or local law. The application shall include acknowledgment that the applicant understands that
the final certificate of occupancy will be issued only if the applicant provides copies of the required federal,
state, and local permits or letters stating that a permit is not required.
G. The application shall include acknowledgment by the applicant that representatives of any federal, state or
local unit of government with regulatory authority over the project are authorized to enter upon the property to
inspect the development.
H. The riparian habitat zone shall be delineated on the site plan by the applicant at the time of application for
subdivision approval or floodplain development permit for all development proposals within 300 feet of any
stream or shoreline.
I. If the project is located in the regulatory floodplain and includes activities not listed in ACC 15.68.130(C) and
(D), the application shall include a habitat impact assessment. If that assessment determines that impacts
would result from the project, the application shall also include a habitat mitigation plan.
J. 15.68.440 Habitat Impact Assessment.
Unless allowed under ACC 15.68.130(C) or (D), anSections 15.68.370 and 15.68.380, a permit application to
develop in the regulatory floodplainSpecial Flood Hazard Area shall include an assessment of the impact of the
project on federal, state or locally protected species and habitat, water quality and aquatic and riparian habitat.
The assessment shall be:
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A. 1. A biological evaluationA Biological Evaluation or biological assessment that has received
concurrence from the U.S. Fish and Wildlife ServiceBiological Assessment developed per 50 C.F.R.,
Subsection 402.12 to initiate Federal Interagency consultation under Endangered Species Act Section 7.a.2;
or,
A.B. Documentation that the National Marine Fisheries Service, pursuant toactivity fits within Section 74.d
of the Endangered Species Act; or,
B.C. 2. Documentation that the activity fits within a habitat conservation planHabitat Conservation Plan
approved pursuant to Section 10 of the Endangered Species Act, where any such assessment has been
prepared or is otherwise made available; or
3. Documentation that the activity fits within Section 4(d) of the Endangered Species Act; or
C.D. 4. An assessment prepared in accordance with Regional Guidance for Floodplain Habitat
Assessment and Mitigation, FEMA Region X, 20102013. The assessment shall determine if the project would
adversely affect:
1. a. Species that are Federal, state or local listed as threatened or endangered.
1.2. The primary constituent elements identified for critical habitat when a species is listed as
threatened or endangered;delineated, including but not limited to water quality, water quantity, flood
volumes, flood velocities, spawning substrate, and/or floodplain refugia for listed salmonids.
2.3. b. Essential fish habitatFish Habitat designated by the National Marine Fisheries Service;.
3.4. c. Fish and wildlife habitat conservation areas;.
d. Vegetation communities and habitat structures;
e. Water quality;
f. Water quantity, including flood and low flow depths, volumes and velocities;
g. The channel’s natural planform pattern and migration processes;
h. Spawning substrate, if applicable; and/or
i. Floodplain refugia, if applicable.
5. K. Other protected areas and elements necessary for species conservation.
15.68.450 Habitat Mitigation Plan.
A. 1. A. If the assessment conducted under subsection J of this sectionSection 15.68.440 concludes
the project is expected to have an adverse effect on water quality and/or aquatic or riparian habitat or habitat
functionsfunction, the applicant shall provide a plan to mitigate those impacts, in accordance with Regional
Guidance for Floodplain Habitat Assessment and Mitigation, FEMA Region X, 20102013.
1. a. For projects or those portions of a project located within the regulatory floodplain but
outside of the protected area1. If the USFWS or NMFS issues an Incidental Take Permit under
Section 10 of the Endangered Species Act or a Biological Opinion under Section 7 of the Endangered
Species Act; then it can be considered to quality as a plan to mitigate those impacts.
2. 2. If the project is located in the Protected Area, the mitigation plan shall stipulate
avoidance measures as are needed to ensure that there is no adverse effect during any phase of the
project. No compensatory mitigation is allowed in the Protected Area.
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1.3. 3. If the project is located outside the Protected Area, the mitigation plan shall include
such avoidance, minimization, restoration, or compensation measures as are appropriate to mitigate
the adverse effects of the project.so that indirect adverse effects of development are mitigated such
that equivalent or better habitat protection is provided for the following functions:
b. For projects or those portions of a project located within the protected area, the project
shall be revised to include such appropriate measures as are needed to ensure that there is
no adverse effect due to the project. Minimization measures are not allowed in the protected
area, unless they, in combination with other measures, result in no adverse effect.
a. 2. a. Stormwater: Reduce flood volumes and stormwater runoff from new
development by ensuring that increased volumes of stormwater reach the river at the same
frequency, timing and duration as historical runoff. Low Impact Development (LID) is required
to be incorporated as described in Section 15.68.270(.B).
b. b. Riparian Vegetation: Maintain or replace riparian function by
providing equivalent area, diversity, and function of riparian vegetation as currently exists on
the site. Riparian retention requirements are outlined in ACC 15.68.400.
c. c. Hyporheic Zones: No activity is allowed that interferes with the
natural exchange of flow between surface water, groundwater and hyporheic zone, however,
natural hyporheic exchange may be enhanced or restored.
d. d. Wetlands: Wetland function must be maintained or replaced by
providing equivalent function.
e. e. Large Woody Debris: Any large woody debris (LWD) removed from
the floodplain must be replaced in kind, replicating or improving the quantity, size, and species
of the existing LWD per Washington Department of Fish and Wildlife Aquatic Habitat
Guidelines.
4. 4. No new stream crossings are allowed outside the Protected Area unless approval
has been obtained as stated in Section 15.68.460.(A).
B. B. The plan’s habitat mitigation activities shall be incorporated into the proposed project. The
floodplain development permit shall be based on the redesigned project and its mitigation components.
C. L. C. As required in Section 15.68.230, the floodplain administrator or designee shall not issue a
certificate of occupancy or final permits until all work identified in the Habitat Assessment and mitigation plan
has been completed or the applicant has provided the necessary assurance that unfinished portions of the
project will be completed, in accordance with Section 15.68.230(.A).
C.D. D Third – -Party Review. For the habitat impact assessment required in sSubsection J15.68.440
of this section or the habitat mitigation plan required in subsection K of this section, the city may require third-
party review when the professional opinions of the applicant’s representative and the city’s reviewers cannot be
reconciled. Third-party review requires the applicant’s habitat impact assessment, habitat mitigation plan,
and/or additional technical studies to be reviewed by an independent third party, paid for by the applicant but
hired by the city. Third-party review shall be conducted by a qualified consultant as defined in the Floodplain
Habitat Assessment and Mitigation Regional Guidance, FEMA Region X, 2010.2013.
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15.68.136 Floodplain 460 Alteration of Watercourses.
A. A. In addition to the other requirements in SectionChapter 15.68, if a project will alter or relocate
boundaries of the SFHA, then the applicant shall also submit a request for a Conditional Letter of Map Revision
(CLOMR), where required by FEMA with engineering documentation and analysis regarding the proposed
change. The project will not be approved unless FEMA issues the CLOMR (which requires Endangered
Species Act consultation) and the provisions of the letter are made part of the permit requirements. If the
change to the BFE or boundaries of the SFHA would normally require a Letter of Map Change, then the project
proponent shall initiate, and receive approval of, a Conditional Letter of Map Revision (CLOMR) prior to
approval of the development permit expiration. The project shall be constructed in a manner consistent with the
approved CLOMR.
B. If there has been no start of construction, a floodplain development permit shall expire 180 days after
the date of issuance. Where the applicant documents a need for an extension beyond this period due to
conditions beyond the applicant’s control, the floodplain administrator may authorize one or more extensions.
C. 15.68.140 Designation of the floodplain administrator.
D. The director of the planning and development department, or the director’s designee, is hereby
appointed to administer and implement this chapter by granting or denying B. If a CLOMR application is made,
then the project proponent shall also supply the full CLOMR documentation package to the Floodplain
Administrator to be attached to the floodplain development permit applications in accordance with its
provisions.
E. 15.68.141 Duties of the floodplain administrator.
F. Duties of the floodplain administrator shall include, but not be limited to:
G. A. Review all floodplain development permits to determine that the permit requirements of this
chapter have been satisfied.
H.B. B. Review all floodplain 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,
including those local, state or federal permits that may be all required to assure compliance with the
Endangered Species Act and/or other appropriate state or federal lawsproperty owner notifications.
I. C. Review all. The floodplain development permits to determine if the proposed development is
located in the protected area. If located in the protected area, ensure that the applicable provisions of this
chapter are met.
J. D. Ensure that all development activities within the regulatory floodplain of the city meet the
requirements of this chapter.
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K. E. Inspect all development projects before, during and after construction to ensure compliance with
all provisions of this chapter, including proper elevation of the structure.
L. F. Maintain for public inspection all records pertaining to the provisions of this chapter.
M. G. Submit reports as required for the National Flood Insurance Program.
N. H. Notify FEMA of any proposed amendments to this chapter.
O. I. Cooperate with state and federal agencies to improve flood and other technical data and
administrator or designee shall notify FEMA of any new data that would revise the FIRM.
P. J. Make interpretations, where needed, as to the exact location of the boundaries of the regulatory
floodplain, the SFHA and the protected area (e.g., where there appears to be a conflict between the mapped
SFHA boundary and actual field conditions as determined by the base flood elevation and ground elevations).
Q. 15.68.150 Duties and responsibilities of the public works department.
R. Duties of the public works department regarding flood hazard areas shall include, but not be limited to:
S. A. Permit Review.
T. 1. Review all development permits to determine that the permit requirements of this chapter have
been satisfied;
U. 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;
V. 3. Review all development permits to determine if the proposed development is located in the
floodway. If located in the floodway, assure that the encroachment provisions of ACC 15.68.160(C) are met.
W. B. Use of Other Base Flood Data. When base flood elevation data has not been provided in
accordance with ACC 15.68.060(C), the city engineer shall obtain, review, and reasonably utilize any base
flood elevation and floodway data available from a federal, state or other sources in order to administer this
chapter.
X. C. Information to Be Obtained and Maintained.
Y. 1. Where base flood elevation data has not otherwise been provided in accordance with this chapter,
obtain and record the actual elevation (in relation to mean sea level) of the lowest habitable floor (including
basement) of all new or substantially improved structures, and whether or not the structure contains a
basement. This information shall be recorded on a current FEMA Elevation Certificate (FEMA Form 81-31),
signed and sealed by a professional land surveyor, currently licensed in the state of Washington.
Z. 2. For all new or substantially improved floodproofed structures:
AA. a. Verify and record the actual elevation (in relation to mean sea level); and
BB. b. Maintain the floodproofing certifications required in this chapter.
CC. 3. Maintain for Public Inspection All Records Pertaining to the Provisions of This Chapter. This
information shall be recorded on a current FEMA Floodproofing Certificate (FEMA Form 81-65), by a
professional engineer, currently licensed in the state of Washington.
DD. D. Alteration of Watercourses.
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EE.C. 1. Notify adjacent communities and the Washington Department of Ecology prior to any alteration or
relocation of a watercourse, and submit evidence of such notification to the Federal Insurance
Administration;FEMA.
FF.D. 2. Require that maintenance isD. Maintenance shall be provided within the altered or relocated portion
of said watercourse so that the flood- carrying capacity is not diminished. If the maintenance program does not
call for cutting of native vegetation, the system shall be oversized at the time of construction to compensate for
said vegetation growth or any other natural factor that may need future maintenance.
E. 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 a conflict between a
mapped boundary and actual field conditions). The person contesting the location of the boundary shall be
given a reasonable opportunity to appeal the interpretation.
F. Appeals of determinations made pursuant to this chapter shall be filed with the city’s public works director
within 20 working days after the final city engineer decision is issued. The public works director shall have 15
working days to review the appeal, determine whether to uphold or modify the city engineer’s decision, and
notify the applicant of such determination. The decision of the public works director shall be final. The city
engineer’s and director’s decision shall be granted consistent with the standards of Section 60.6 of the Rules
and Regulations of the National Flood Insurance Program (44 CFR 59-76). (Ord. 6295 § 2, 2010; Ord. 6182
§ 4, 2008; Ord. 6161 § 1, 2008; Ord. 4820 § 1, 1995; Ord. 4357 § 2(4.3), 1989.)
15.68.151 Duties and responsibilities of the planning and development department.
Duties of the planning and development department shall include, but not be limited to:
A. Permit Review.
1. Review all building-related development permits to determine that the permit requirements of this
chapter have been satisfied including building, addition and alteration permits;
2. Review all building-related 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;
and
3. Review all building-related projects to determine that the procedures for building projects within a
special flood hazard area have been applied.
B. Information to Be Obtained and Maintained.
1. Where base flood elevation data is provided through the flood insurance study or required as in ACC
15.68.150(B), obtain and record the actual 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:
a. Verify and record the actual elevation (in relation to mean sea level); and
b. Maintain the floodproofing certifications required in this chapter;
3. Maintain for public inspection all building-related records pertaining to the provisions of this chapter.
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Article V. Provisions for Flood Hazard Protection
15.68.160 Standards of the public works department.
A. Utilities.
1. All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of
floodwaters into the system.
2. New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration
of floodwaters into the systems and discharge from the systems into floodwaters.
3. On-site waste disposal systems shall be located to avoid impairment to them or contamination from
them during flooding.
4. All new streets shall be designed to ensure the lowest finished surface elevation is a minimum of one
foot higher than the adjacent 100-year flood elevation.
5. All new development shall be designed and located to minimize the impact on flood flows, flood
storage, water quality, and habitat.
a. Stormwater and drainage features shall incorporate low impact development techniques that
mimic predevelopment hydrologic conditions, such as stormwater infiltration, rain gardens, grass
swales, filter strips, disconnected impervious areas, permeable pavement, and vegetative roof
systems.
b. If the proposed project will create new impervious surfaces so that more than 10 percent of the
portion of the lot in the regulatory floodplain is covered by impervious surface, the applicant shall
demonstrate that there will be no net increase in the rate and volume of the stormwater surface runoff
that leaves the site or that the adverse effect is mitigated as required in ACC 15.68.135(J) and (K).
6. The site plan required in this chapter shall account for surface drainage to ensure that:
a. Existing and new buildings on the site will be protected from stormwater runoff; and
b. The project will not divert or increase surface water runoff onto neighboring properties.
7. Utilities. Water wells shall be located outside the floodway and shall be protected to the FPE.
B. 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.
C. Floodway Standards.
1. In addition to the other requirements of this chapter, a project to develop in the floodway as delineated
pursuant to this chapter shall meet the following criteria:
a. The applicant shall provide a certification by a registered professional engineer demonstrating
through hydrologic and hydraulic analyses performed in accordance with standard engineering
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practice that the proposed development would not result in any increase in flood levels during the
occurrence of the base flood discharge.
b. Construction or reconstruction of residential structures is prohibited within designated floodways,
except for the following. The following exceptions must still meet all other requirements in this
chapter:
i. Repairs, reconstruction, or improvements to a residential structure which do not increase the
ground floor area, providing the cost of which does not exceed 50 percent of the market value of
the structure either (A) before the repair or reconstruction is started, or (B) if the structure has
been damaged, and is being restored, before the damage occurred. Any project for
improvement of a structure to correct existing violations of state or local health, sanitary, or
safety code specifications which have been identified by a local code enforcement official and
which are the minimum necessary to assure safe living conditions, or to an historic structure,
may be excluded from the 50 percent calculations;
ii. Repairs, replacement, reconstruction, or improvements to existing farmhouses located in
designated floodways and located on designated agricultural lands that do not increase the
building’s total square footage of encroachment and are consistent with all requirements of
WAC 173-158-075;
iii. Repairs, replacement, reconstruction, or improvements to substantially damaged residential
dwellings other than farmhouses that do not increase the building’s total square footage of
encroachment and are consistent with all requirements of WAC 173-158-076; or
iv. Repairs, reconstruction, or improvements to residential structures identified as historic
structures that do not increase the building’s dimensions.
2. In riverine special flood hazard areas where a floodway has not been delineated pursuant to this
chapter, the applicant for a project to develop in the SFHA shall provide a certification by a registered
professional engineer demonstrating through hydrologic and hydraulic analyses performed in accordance
with standard engineering practice that the proposed development and all other past or future similar
developments would not cumulatively result in an increase of flood levels during the occurrence of the
base flood discharge by more than one foot.
15.68.161 Standards of the planning and development department.
In all areas of special flood hazard the following standards are required:
A. 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. This requirement is in
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addition to other anchoring requirements for resisting wind forces. (Reference FEMA’s “Manufactured
Home Installation in Flood Hazard Areas” guidebook for additional techniques.)
B. 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.
C. Review of Building Permits. Where elevation data is not available either through the flood insurance study
or from another authoritative source, applications for building permits shall be reviewed to assure that proposed
construction will be reasonably safe from flooding. The test of reasonableness is a local judgment and includes
use of historical data, high water marks, photographs of past flooding, etc., where available. Failure to elevate
at least two feet above grade in these zones may result in higher insurance rates.
D. Native Vegetation. The site plan required for development in the regulatory floodplain shall show existing
native vegetation.
1. In the riparian habitat zone, native vegetation shall be left undisturbed, except if in connection with an
activity allowed in the regulatory floodplain without a permit, and except for activities with the sole purpose
of creating, restoring or enhancing natural functions associated with floodplains, streams, lakes, estuaries,
marine areas, habitat, and riparian areas that meet federal and state standards, provided the activities do
not include structures, grading, fill, or impervious surfaces.
2. Outside the riparian habitat zone, removal of native vegetation shall not exceed 35 percent of the
surface area of the portion of the site in the regulatory floodplain. Native vegetation in the riparian habitat
zone portion of the property can be counted toward this requirement.
3. If the proposed project does not meet the criteria of this chapter, a habitat impact assessment shall be
conducted pursuant to ACC 15.68.135(J) and, if indicated by that assessment, a habitat mitigation plan
shall be prepared and implemented pursuant to ACC 15.68.135(K).
15.68.170 Additional standards of the planning and development department.
In all areas of special flood hazard where base flood elevation data is provided as set forth in this chapter, the
following provisions are required:
A. 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. Enclosed crawl space areas
no taller than three feet, measured from the lowest ground within the crawl space to the bottom of the
structural system directly supporting the floor slab or sheathing above, shall not be considered as a
basement.
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2. Fully enclosed areas below the lowest floor that are subject to flooding are prohibited, or shall be designed
to automatically equalize hydrostatic and hydrodynamic flood forces on exterior walls by allowing for the entry
and exit of floodwaters.
Designs for meeting this requirement must either be certified by a registered professional engineer or
architect or must meet or exceed the following minimum criteria:
a. A minimum of two openings having a total net area of not less than one square inch for every
square foot of enclosed area subject to flooding shall be provided;
b. The bottom of all openings shall be no higher than one foot above grade;
c. Openings may be equipped with screens, louvers, or other coverings or devices; provided, that
they permit the automatic entry and exit of floodwaters.
3. The structure shall be aligned parallel with the direction of flood flows.
4. The structure shall be anchored to prevent flotation, collapse, or lateral movement of the structure.
5. All materials below the FPE shall be resistant to flood damage and firmly anchored to prevent flotation.
Materials harmful to aquatic wildlife, such as creosote, are prohibited below the FPE.
6. Electrical, heating, ventilation, duct work, plumbing, and air-conditioning equipment and other service
facilities shall be elevated above the FPE. Water, sewage, electrical, and other utility lines below the FPE
shall be constructed so as to prevent water from entering or accumulating within them during conditions of
flooding.
7. Fully enclosed areas below the lowest floor that are subject to flooding are prohibited; provided, that
those areas may be used only for parking, storage, or building access and only if they are designed to
automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of
floodwaters. Designs for meeting this requirement shall either be certified by a registered professional
engineer or licensed architect or meet or exceed the following minimum criteria:
a. A minimum of two openings having a total net area of not less than one square inch for every
square foot of enclosed area subject to flooding shall be provided.
i. 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 or devices; provided, that
they permit the automatic entry and exit of floodwaters.
B. Nonresidential Construction. New construction and substantial improvement to any commercial, industrial
or other nonresidential structure shall have the lowest floor, including basement, elevated one foot or more
above the level of the base flood elevation. As an alternative to elevation, a new or substantial improvement to
a nonresidential structure, and its attendant utility and sanitary facilities, may be dry floodproofed in A zones.
The project shall meet the following requirements:
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;
2.1. 2. Have structural components capable of resisting hydrostatic and hydrodynamic loads and
effects of buoyancy;
3. Be certified by a registered professional engineer or a registered professional architect that the design
and methods of construction are in accordance with accepted standards of practice for meeting provisions
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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 ACC 15.68.150(C)(2);
4. Nonresidential structures that are elevated, not floodproofed, must meet the same standards for space
below the lowest floor as described in subsection (A)(2) of this section;
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 constructed to one foot
above the base flood level will be rated as one foot below that level).
C. Manufactured Homes. All manufactured homes to be placed or substantially improved within Zones A1 –
30, AH, and AE 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.
D. Recreational Vehicles. Recreational vehicles placed on sites are required to either:
1. Be on the site for fewer than 180 consecutive days; or
2. Be fully licensed and ready for highway use, on wheels or jacking system, attached to the site only by
quick disconnect type utilities and security devices, and have no permanently attached additions; or
3. Meet the requirements of subsection C of this section and the elevation and anchoring requirements
for manufactured homes.
E. Hazardous Materials. No new development shall create a threat to public health, public safety, or water
quality. Chemicals, explosives, gasoline, propane, buoyant materials, animal wastes, fertilizers, flammable
liquids, pollutants, or other materials that are hazardous, toxic, or a threat to water quality are prohibited from
the regulatory floodplain. This prohibition does not apply to small quantities of these materials kept for normal
household use or to materials kept in approved containers above the FPE or in a dry floodproofed
nonresidential building.
F. Small Structures. A low cost building such as a detached garage, boathouse, pole barn, or storage shed
that is no larger than 500 square feet and is not used for human habitation may be exempt from the elevation
requirement of this chapter, provided:
1. It is used only for parking or storage;
A. 2. It is constructed and placed on the building site so as to offer minimum resistance to the flow of
floodwaters;
B.A. 3. It is anchored to prevent flotation which may result in damage to other structures;
4. All portions of the structure below the FPE must be constructed of flood-resistant materials;
5. Service utilities such as electrical and heating equipment meet the standards of this chapter;
6. It has openings to allow free flowage of water that meet the criteria of this chapter;
7. The project meets all the other requirements of this chapter.
G. Location of Structures. Structures and other development shall be located to avoid flood damage.
1. If a lot has a buildable site out of the regulatory floodplain, all new structures shall be located in that
area.
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2. If a lot does not have a buildable site out of the regulatory floodplain, all new structures, pavement,
and other development must be sited in the location that has the least impact on habitat by locating the
structures as far from the water body as possible or placing the structures on the highest land on the lot.
H. Critical Facilities.
1. Construction of new critical facilities shall be, to the extent possible, located outside the limits of the
regulatory floodplain.
2. Construction of new critical facilities shall be permissible if no feasible alternative site is available,
provided:
a. Critical facilities shall have the lowest floor elevated three feet above the base flood elevation or
to the height of the 500-year flood, whichever is higher. If there is no available data on the 500-year
flood, the permit applicants shall develop the needed data in accordance with FEMA mapping
guidelines.
b. Access to and from the critical facility shall be protected to the elevation of the 500-year flood.
15.68.180 Floodways and community acknowledgement of FEMA map amendments.
A. Notwithstanding any other provision of this chapter, the city may permit encroachments within the adopted
regulatory floodway upon receipt of approval of the Federal Insurance Administrator and completion of the
conditions of this section.
1. Prior to a developer being authorized to encroach upon the adopted regulatory floodway to an extent
which will cause base flood elevation increases in excess of those permitted in subsection A of this
section, the developer shall provide, for city review and submission to the Federal Insurance
Administrator, the following:
a. A request for conditional approval of map change and the appropriate initial fee as specified by
Section 72.3 of 44 CFR Chapter I Federal Emergency Management Agency or a request for
exemption from fees as specified by Section 72.5 of 44 CFR Chapter I Federal Emergency
Management Agency. Sections 72.3 and 72.5 of 44 CFR Chapter I Federal Emergency Management
Agency are herein adopted by reference in their entirety including any future amendments thereto;
b. An evaluation of alternatives which would not result in a base flood elevation increase above that
permitted under subsection A of this section demonstrating why these alternatives are not feasible;
c. Documentation of individual legal notice to all impacted property owners within and outside of the
community, explaining the impact of the proposed action on their property;
d. Written concurrence of the chief executive officer of any other communities impacted by the
proposed actions;
e. Written certification that no structures are located in areas which would be impacted by the
increased base flood elevation;
f. A request for revision of base flood elevation determination according to the provisions of Section
65.6 of 44 CFR Chapter I Federal Emergency Management Agency. Section 65.6 of 44 CFR Chapter
I Federal Emergency Management Agency is herein adopted by reference in its entirety;
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g. A request for floodway revision in accordance with the provisions of Section 65.7 of 44 CFR
Chapter I Federal Emergency Management Agency. Section 65.7 of 44 CFR Chapter I Federal
Emergency Management Agency is herein adopted by reference in its entirety.
B. City Review of Changes to Flood Hazard Data.
1. All requests to revise or change the flood hazard data, including requests for a letter of map revision
and a conditional letter of map revision, shall be reviewed by the floodplain administrator.
a. The floodplain administrator shall not sign the community acknowledgement form for any
requests based on filling or other development, unless the applicant for the letter documents that
such filling or development is in compliance with this chapter.
b. The floodplain administrator shall not approve a request to revise or change a floodway
delineation until FEMA has issued a conditional letter of map revision that approves the change.
c. Upon receipt of the Federal Insurance Administrator’s conditional approval of map change and
prior to the approval of the proposed encroachments, the developer shall compensate the city for all
costs incurred by the city which are associated with:
i. The city’s adoption of floodplain management ordinances incorporating the increased base
flood elevations and/or revised floodway reflecting the post-project condition;
ii. The city’s submittal of evidence to the Federal Insurance Administrator of the city’s adoption
of said revised floodplain management ordinances;
iii. Within three months of completion of the proposed encroachments, the developer shall be
responsible for providing certified record drawings and/or technical or scientific data to the city
for submittal to the Federal Insurance Administrator.
2. If an applicant disagrees with the regulatory data prescribed by this chapter, he/she may submit a
detailed technical study needed to replace existing data with better data in accordance with FEMA
mapping guidelines or Regional Guidance for Hydrologic and Hydraulic Studies FEMA Region X, 2010. If
the data in question are shown on the published FIRM, the submittal must also include a request to FEMA
for a conditional letter of map revision.
3. All new hydrologic and hydraulic flood studies conducted pursuant to this chapter shall consider future
conditions and the cumulative effects from anticipated future land use changes in accordance with
Regional Guidance for Hydrologic and Hydraulic Studies, FEMA Region X, 2010. If there is a study in
existence on the date this provision becomes effective that meets the rest of this chapter’s criteria, it may
be used, even if it does not account for future conditions.
15.68.190 Developments within areas of special flood hazard.
Notwithstanding any other provision of this chapter, the city may permit developments within special flood
hazard areas. Prior to approval for a development which will increase the water surface elevation of the base
flood by more than one foot, a developer must comply with the requirements set forth in ACC 15.68.180(A).
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15.68.200 Compensatory storage requirements.
A. Development proposals shall not reduce the effective flood storage volume at base flood elevation. Where
fill, grading or other activities that may displace the effective base flood storage volume are proposed,
compensatory storage shall be required. Compensatory storage shall:
1. Provide equivalent volume at equivalent elevations to that being displaced.
2. Hydraulically connect to the source of the flooding.
3. Provide compensatory storage in the same construction season as when the displacement of flood
storage volume occurs. Allowances may be granted on a case-by-case basis to allow sequential
construction if the timing of the work cannot meet wintertime/flood construction schedules.
4. Occur on site or, if approved by the city engineer, at a hydraulically connected off-site location.
5. Provide documentation of a restrictive easement acceptable to the engineering division to ensure
continued existence of the compensatory flood storage.
B.A. 6. The newly created storage area shall be graded and vegetated to allow fish access during flood
events without creating fish stranding sites.
B. Certification by a registered professional engineer may be required as documentation that the
compensatory storage requirement shall be met by the development proposal.
Page 107 of 117
AUBURN
VALUES
SERVICE
ENVIRONMENT
ECONOMY
CHARACTER
SUSTAINABILITY
WELLNESS
CELEBRATION
COMMUNITY DEVELOPMENT
DEVELOPMENT ENGINEERING
FLOODPLAIN DEVELOPMENT
CODE UPDATE
STEVEN STURZA
PLANNING COMMISSION
APRIL 21, 2020
Department of Community Development
Planning Building Development Engineering Permit Center
Sustainability Community Services ●Code EnforcementPage 108 of 117
FEMA’S LETTER OF DETERMINATION
SERVICE ENVIRONMENT ECONOMY CHARACTER SUSTAINABILITY WELLNESS CELEBRATIONPage 109 of 117
Suspension of NFIP eligibility
No mortgages or home equity loans in
floodplain areas
No renewals of existing flood insurance policies
Loss of most forms of Disaster Assistance
No federal grants or loans
Loss of subsidized insurance for Pre-FIRM
structures
Potential impacts to Endangered Species
Failure of communities to properly regulate
flood hazard areas may bring lawsuits
ORDINANCE NON-COMPLIANCE
SERVICE ENVIRONMENT ECONOMY CHARACTER SUSTAINABILITY WELLNESS CELEBRATIONPage 110 of 117
What are we proposing to update?
Created from the State of Washington Model Flood Damage Prevention Ordinance
Reviewed & modified by City of Auburn Community Development and Public Works
Been reviewed by FEMA and Department of Ecology
Additional Comments have been received from Department of Ecology on 3/2/20
that have been incorporated into the Draft Code Since the March 3rd meeting
STAFF PROPOSED UPDATES TO ACC 15.68
MODEL ORDINANCE
SERVICE ENVIRONMENT ECONOMY CHARACTER SUSTAINABILITY WELLNESS CELEBRATIONPage 111 of 117
Additional Comments from Department of Ecology Provided
on 3/2/2020 and later dates
Additional updates to the definitions
Update the reference to the Flood Insurance Studies to be 8/19/2020
A portion of the Urban Growth Area is in an area covered by the Pierce County FIS,
the City should also adopt the Pierce County FIS and FIRMs
Basic floodplain permit a pplication requirements are needed in code
A new section for Notification to Other Entities was added
Building construction and documentation requirements were slightly updated
Additional variance criteria was added
A new section for Standard for Shallow Flooding Areas (AO Zones) was added
STAFF PROPOSED UPDATES TO ACC 15.68
MODEL ORDINANCE
SERVICE ENVIRONMENT ECONOMY CHARACTER SUSTAINABILITY WELLNESS CELEBRATIONPage 112 of 117
Reorganize ACC, Chapter 15.68 to correspond to the layout of the Model Ordinance
Update the definitions section to have the latest definitions per NFIP, NMFS, FEMA,
DOE and City of Auburn.
Remove all of the permit application submittal criteria from ACC, Chapter 15.68
Information already provided in ACC 18.70.025 for variances is removed to avoid
redundancy
Minimum 15-foot setback from the protected area
Remove a date for assessing cumulative improvements
Increasing the requirements for what is to be addressed in Habitat Mitigation Plans
STAFF PROPOSED UPDATES TO ACC 15.68
MODEL ORDINANCE UPDATES
SERVICE ENVIRONMENT ECONOMY CHARACTER SUSTAINABILITY WELLNESS CELEBRATIONPage 113 of 117
STAFF PROPOSED UPDATES TO ACC 15.68
RIPAIRIAN BUFFER ZONE
SERVICE ENVIRONMENT ECONOMY CHARACTER SUSTAINABILITY WELLNESS CELEBRATIONPage 114 of 117
STAFF PROPOSED UPDATES TO ACC 15.68
CHANNEL MIGRATION ZONE
SERVICE ENVIRONMENT ECONOMY CHARACTER SUSTAINABILITY WELLNESS CELEBRATIONPage 115 of 117
STAFF PROPOSED UPDATES TO ACC 15.68
CURRENT EFFECTIVE FIRM (MAY 1995)
SERVICE ENVIRONMENT ECONOMY CHARACTER SUSTAINABILITY WELLNESS CELEBRATIONPage 116 of 117
STAFF PROPOSED UPDATES TO ACC 15.68
PRELIMINARY FIRM (8/19/2020)
SERVICE ENVIRONMENT ECONOMY CHARACTER SUSTAINABILITY WELLNESS CELEBRATIONPage 117 of 117