HomeMy WebLinkAboutITEM IV-AAgenda Subject Date: Ordinance No. 6295 amending City of Auburn floodplain and flood March 3, 2010
hazard regulations currently specified in Chapter 15.68 (Flood Hazard
Areas) of the Auburn City Code and referenced in Titles 14, 16, 17, and
18 of the Auburn Cit Code.
Department: Attachments: Budget Impact: NIA
Planning and Development (1) Ordinance No. 6295 (2) City of Auburn Regulatory
Floodplain Map
(3) Draft -Regional Guidance for
Floodplain Habitat Assessment and
Mitigation dated January 1, 2010
(4) Draft -Regional Guidance for NFIP-ESA Hydrologic and Hydraulic
Studies dated Janua 1, 2010
Administrative Recommendation: City Council to introduce and adopt Ordinance No. 6295
Background Summary:
On November 17, 2008, Auburn City Council enacted a moratorium on development within the Federal Emergency Management Agency (FEMA) identified 100-year floodplain. This moratorium was
enacted as
a result of a finding (Biological Opinion) issued by the National Marine Fisheries Service (NMFS) that
administration of the National Flood Insurance Program (NFIP) jeopardizes species protected under the
Endangered Species Act (ESA). As a result of the NMFS finding, FEMA and communities participating in
the NFIP are required to implement a series of actions, including adoption of regulations to ensure compliance with the ESA. The purpose of the moratorium was to give these federal agencies
time to
complete a model floodplain ordinance and other technical assistance for local jurisdictions, and in the
interim, to limit liability to private parties and the City.
The City of Auburn has participated in the ongoing review of a model floodplain ordinance and related
guidance documents being developed by FEMA, and has provided numerous review comments since mid 2009. Based on the City's understanding of the new NFIP requirements gained through participation
in
the NFIP model ordinance development process, staff is recommending that the City move forward at this
time to adopt amendments to Titles 14, 15, 16, 17, and 18 relating to the City's floodplain development
regulations to incorporate the ESA requirements contained in the NMFS Biological Opinion.
Adoption of floodplain regulation amendments that meet the NFIP-ESA requirements will address the
underlying reason for the enactment of the floodplain development moratorium and allow for the
moratorium to be discontinued.
The Auburn Planning Commission held a duly noticed public hearing at the Commission's regular meeting
on February 23, 2010, and upon conclusion of the hearing and the Commission's further discussion and deliberation did then recommend by positive motion vote to forward the proposed amendments
to the City
Council for consideration and adoption action.
The Public Works Committee reviewed and discussed the proposed amendments at a regular meeting of
the Committee on March 1, 2010. Committee members requested that staff refine and clarify Section 11
of the draft ordinance entitled "Effect of subsequent amendments".
Ordinance No. 6295 (Agenda Bill Attachment 1) has been revised to address the refinements requested
by the Public Works Committee, to amend the fee schedule for floodplain development permits and
associated reviews, to add a provision for third party review of habitat impact assessments and mitigation
plans, and to revise the format of the ordinance by incorporating the proposed amendments to Auburn City Code into the body of the ordinance, instead of referencing them as separate
exhibits.
Reviewed by Council & Committees: Reviewed by Departments & Divisions: ❑ Arts Commission COUNCIL COMMITTEES: ®Building ❑ M&0
❑ Airport ❑ Finance ❑ Cemetery ❑ Mayor
❑ Hearing Examiner ❑ Municipal Services ❑ Finance ®Parks ❑ Human Services ❑ Planning & CD ❑ Fire ®Planning
❑ Park Board ®Public Works ®Legal ❑ Police
® Planning Comm. ❑ Other ®Public Works ❑ Human Resources
Action: Committee Approval: ❑Yes ❑No
Council Approval: ❑Yes ❑No Call for Public Hearing / /
Referred to Until / / Tabled Until / /
Councilmember: Norman Staff: Sn der
Meeting Date: March 8, 2010 Item Number:
ORDINANCE N0.6_
AN ORDINANCE OF THE CITY COUNCIL OF THE CITY
OF AUBURN, WASHINGTON, RELATING TO
FLOODPLAIN MANAGEMENT REGULATIONS;
ADOPTING REGULATIONS INCORPORATING FEDERAL
HABITAT PROTECTION REQUIREMENTS INTO
EXISTING REGULATIONS, ESTABLISHING
REQUIREMENTS FOR A FLOODPLAIN DEVELOPMENT
PERMIT, UPDATING RELATED PROVISIONS OF LAW,
AND AMENDING CHAPTERS 14.03 AND 15.68, AND
SECTIONS 16.10.010, 16.10.070, 17.04.300, 17.09.050,
AND 17.14.110 OF THE AUBURN CITY CODE, AND
CRERATING NEW SECTIONS 17.04.305, 17.04.335 AND
18.70.025 OF THE AUBURN CITY CODE, AND
REPEALING SECTION 17.04.045 OF THE AUBURN CITY
CODE CONNECTED THEREWITH
WHEREAS, the City is required, as a condition of continued eligibility in the
National Flood Insurance Program (NFIP} to adopt floodplain management regulations
that meet the requirements of the federal flood plain management criteria for flood-
prone areas in the Code of Federal Regulations (44CFR 60.3} ;and
WHEREAS, the City currently regulates floodplain management by using a
combination of specific floodplain management regulations, critical area regulations,
shoreline management regulations, and State Environmental Policy Act (SEPA)
regulations; and
WHEREAS, in October, 2008, the City received notice from the Federal
Emergency Management Administration (FEMA) and the National Marine Fisheries
Service (NMFS) that those agencies had collaborated on a position paper that seeks to
prevent continued degradation of existing floodplain, and to promote low impact
development in floodplain areas of the region that could effect endangered species; and
Ordinance No. 6295
March 2, 2010 Page 1 of 43
WHEREAS, FEMA and NMFS took the position that if a permitting agency, such
as the City of Auburn, grants permits in floodplain areas within its boundaries that are
later determined to adversely impact the floodplains and/or endangered species, the
permitting agency will be liable for the resulting "take" on endangered species; and
WHEREAS, in response to the position taken by the federal agencies, the City
imposed a moratorium on development in floodplains within the City, which moratorium
continues to be in effect; and
WHEREAS, FEMA, in consultation with NMFS, began working on a model
ordinance that, if substantively adopted by local jurisdictions, would allow those
jurisdictions to resume permitting development in the floodplain. The provisions of the
model ordinance are intended to help ensure that impacts on the floodplain and on
habitat were properly evaluated and, if necessary, mitigated; and
WHEREAS, the federal agencies invited several local jurisdictions, including
Auburn, to participate in a focus group during the development of this model ordinance;
and
WHERAS, although federal agencies incorporated some of the suggestions from
the local jurisdictions, the substantive requirements that the local jurisdictions must
adopt are mandated by the federal agencies and are not subject to modification by the
local jurisdictions.
WHEREAS, the federal agencies must approve the City's incorporation of the
substantive terms of the model ordinance; however, the provisions of model ordinance
provide sufficient guidance to allow the City to resume processing development permits
in the floodplain in compliance with the interim measure required by NMFS; and
Ordinance No. 6295
March 2, 2010 Page 2 of 43
WHEREAS, It is the Council's intention to adopt the below stated regulations as
interim regulations until such time as the federal agencies approve them as permanent
measures, at which time they shall become permanent regulations.
NOW, THEREFORE, THE CITY COUNCIL OF THE CITY OF AUBURN,
WASHINGTON, DO ORDAIN as follows:
Section 1. Amendment to City Code. Chapter 14.03 of the Auburn City
Code be and the same hereby is amended to read as follows:
Chapter 14.03
TYPES OF PROJECT PERMIT DECISIONS
Sections:
14.03.001 Generally.
14.03.010 Type I decisions.
14.03.020 Type II decisions.
14.03.030 Type III decisions.
14.03.040 Type IV decisions.
14.03.050 Type V decisions.
14.03.060 Legislative nonproject decisions.
14.03.001 Generally.
Project permit decisions are classified into five types, based on whether a
director, the hearing examiner or the city council makes the decision and the process by
which that decision is made. (Ord. 4835 § 1, 1996.)
14.03.010 Type I decisions.
Type I decisions are administrative decisions made by the city which are not
subject to environmental review under the State Environmental Policy Act (SEPA)
codified at Chapter 43.21 C RCW. Type I decisions include, but are not limited to, the
following project applications:
A. Building permit;
B. Plumbing permit;
C. Mechanical permit;
D. Utility permit;
E. Special permit;
F. Excavation permit;
G. Land clearing permit;
H. Grading permit;
I. Floodplain development vvi i~rvl ~~n° permit;
J. Public facility extension agreement;
Ordinance No. 6295
March 2, 2010 Page 3 of 43
K. Right-of-way use permit;
L. Lot line adjustment;
M. Home occupation permit;
N. Temporary use permit (administrative};
0. Administrative use permit;
P. Short subdivision (plat};
Q. Mobile home closure plans. (Ord. 5746 § 2, 2003; Ord. 4835 § 1, 1996.)
14.03.020 Type II decisions.
Type II decisions are administrative decisions made by the city which include
threshold determinations under SEPA. Type II decisions include, but are not limited to,
the following project applications:
A. Building permit;
B. Grading permit;
C. Land clearing permit;
D. Public facility extension agreement;
E. Administrative use permit;
F. Short subdivision (plat}.
G. Floodplain development permit._(Ord. 4835 § 1, 1996.)
14.03.030 Type III decisions.
Type III decisions are quasi-judicial final decisions made by the hearing examiner
following a recommendation by staff. Type III decisions include, but are not limited to,
the following project applications:
A. Temporary use permit;
B. Substantial shoreline development permit;
C. Variance;
D. Special exceptions;
E. Special home occupation permit;
F. Preliminary plat;
G. Conditional use permit;
H. Surface mining permit. (Ord. 6184 § 3, 2008; Ord. 4835 § 1, 1996.)
14.03.040 Type IV decisions.
Type IV decisions are quasi-judicial decisions made by the city council following
a recommendation by the hearing examiner. Type IV decisions include, but are not
limited to, the following project applications:
Rezone (site-specific). (Ord. 6184 § 4, 2008; Ord. 4835 § 1, 1996.}
14.03.050 Type V decisions.
Type V decisions are quasi-judicial decisions made by the city council following a
recommendation by staff. Type V decisions include, but are not limited to, the following
project applications:
Final plat. (Ord. 6184 § 5, 2008; Ord. 4835 § 1, 1996.)
Ordinance No. 6295
March 2, 2010 Page 4 of 43
14.03.060 Legislative nonproject decisions.
Legislative nonproject decisions made by the city council under its authority to
establish policies and regulations are not classified as a "type" of project permit
decision. Legislative nonproject decisions include, but are not limited to, the following
legislative actions:
A. Amendments to the text and map of the comprehensive plan or
development regulations.
B. Amendments to the zoning map (rezones) on a city-wide or area-wide
basis. (Ord. 4835 § 1, 1996.}
Section 2. Amendment to City Code. Chapter 15.68 of the Auburn City
Code be and the same hereby is amended to read as follows:
Chapter 15.68
FLOOD HAZARD AREAS
Sections:
Article I. Statutory Authorization, Findings of Fact, Purpose and Objectives
15.68.010 c+~+~ ~+nry ~i i+hnri~~+inn Reserved. V~VI~NLVI Vt~.l~l 1\.!1 ILVt~IVI 1.-
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 Ras;s fir °sta"!isl ~ RNs ~I!ood 1 -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.
1 Prior Legislation: Orris. 4214 and 4220.
Ordinance No. 6295
March 2, 2010 Page 5 of 43
15.68.135 Floodplain develo ment permit application.
15.68.136 Floodplain development permit expiration.
15.68.140 .Designation of floodplain administrator.
15.68.141 Duties of the floodplain administrator.
15.68.150 Duties and responsibilities of the ^ii~y °""y."°°. Public Works
De artment.
15.68.151 Duties and responsibilities of the r~i+y of ~i ihi irn hi iilrJiny rli,ii~inn V1~ VI WtANlAlll N1d111,A111 1d1VIVIVII
planning and development department.
Article V. Provisions for Flood Hazard Protection
15.68.160 ~-Standards of the ni+„ of Di ihi irn °nrrin°°~rYn~
• • public works department.
15.68.161 ~°n°r~l c+~nrl~rrlc Standards of the r+i+„ of ~i ihi irn hi iilrlinn rli,iicinn vV1lVlbll V~tr1111,At.A11,AV VI~Y VI , \1,.1N1d111 Nb111w111~ 1d1Y1VIV11
planning and development de artment. v
15.68.170 SN°vif~i Additional standards of the 1;.;;!d;n ;v~;s;on
planning and development department.
15.68.180 Floodways, and community acknowledgement of FEMA map
amendments.
15.68.190 Development within areas of special flood hazard.
15.68.200 Compensatory storage equipment.
Article I, c+,f„+~M, n „f~„~;~~f;~~~ Cinrlinn~ purpose
15.68.010 RESERVED Statutes, u;~t" • ut;o
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Ordinance No. 6295
March 2, 2010 Page 6 of 43
15.68.030 Statement of purpose.
It is the purpose of this chapter to promote the public health, safety, and general
welfare, and to minimize public and private losses due to flood conditions in specific
areas by provisions designed:
A. To protect human life health, and to protect property;
B. To minimize expenditure of public money and costly 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;
E. To minimize damage to public facilities and utilities such as water and gas
mains, electric, telephone and sewer lines, streets and bridges located in areas of
special flood hazard;
F. To help maintain a stable tax base by providing for the sound use and
development of areas of special flood hazard so as to minimize future flood blight areas;
G. To ensure that potential buyers are notified that property is in an area of
special flood hazard; and
H. To ensure that those who occupy the areas of special flood hazard
assume responsibility for their actions.
A. Minimize the need for publicly funded and hazardous rescue efforts to
save those who are isolated by flood waters;
B. Minimize expenditure of public money for costly flood damage repair and
flood control projects;
C. Minimize disruption of commerce and governmental services;
D. Minimize damage to public facilities and utilities such as water and gas
mains, electric, telephone and sewer lines, streets, and bridges located;
E. Maintain a stable tax base by providing for the sound use of floodprone
areas so as to minimize future flood blight areas;
F. Ensure that those who occupy areas subject to flooding and channel
migration assume responsibility fortheir actions;
G. Qualify the City of Auburn for participation in the National Flood Insurance
Pro ram, thereby giving citizens and businesses the opportunity to purchase flood
insurance;
H. Maintain the uality 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;
I. Retain the natural channel, shoreline, and floodplain creation rocesses
and other natural floodplain functions that protect, create, and maintain habitat for
threatened and endangered species.
J. Prevent or minimize loss of hydraulic, geomorphic, and ecological
functions of floodplains and stream channels. _(Ord. 6161 § 1, 2008; Ord. 4820 § 1,
1995; Ord. 4357 § 2(1.3), 1989.)
15.68.040 Methods of reducing flood losses.
In order to accomplish its purposes, this chapter includes methods and
provisions for:
Ordinance No. 6295
March 2, 2010 Page 7 of 43
A. Restricting or prohibiting uses which are dangerous to health, safety, and
property due to water or erosion hazards, or which result in damaging increases in
erosion or in flood heights or velocities;
B. Requiring that uses vulnerable to floods, including facilities which serve
such uses, be protected against flood damage at the time of initial construction;
C. Controlling the alteration of natural floodplains, stream channels, and
natural protective barriers, which help accommodate or channel floodwaters;
D. Controlling filling, grading, dredging, and other development which may
increase flood damage; and
E. Preventing or regulating the construction of flood barriers which will
unnaturally divert floodwaters or which may increase flood hazards in other areas.
F. Identif in.,~ the Re , ulato Floodplain, the Special Flood Hazard Area, and
the Protected Area and the supporting technical data needed to delineate those areas.
G. Establishing a permit requirement so that all human development that may
affect flood hazards, water quality, and habitat is reviewed before it is constructed.
H. Setting minimum protection standards for all development to ensure that
the development will not increase the potential for flood lamage or adverse) affect
natural floodplain functions.
I. Setting minimum standards to protect new and substantially improved
structures from flood dama~e.
J. __Specifying additional habitat protection criteria. Some small projects do
not need a permit (see ACC 15.68.1306, C). 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 there will be an
adverse im act, the permit will be denied, unless the roP~ect is redesigned to miti ate
the adverse im acts. (Ord. 6161 § 1, 2008; Ord. 4820 § 1, 1995; Ord. 4357 § 2(1.4),
1989. )
Article II. Definitions
15.68.050 Interpretation of language.
Unless specifically defined in this article, words or phrases used in this chapter
shall be interpreted so as to give them the meaning they have in common usage and to
give this chapter its most reasonable application. (Ord. 6161 § 1, 2008; Ord. 4820 § 1,
1995; Ord. 4357 § 2(2.0), 1989.)
15.68.060 Definitions.
As used in this chapter: "~nno~l" mo~ne ~ rorri ioe~ fnr ~ ro~iio~n~ of o r+i~~i onrrinoorinn rli~iieinn'e
in ~n~i nrn~iieinne of hie r+h~n~or nr ~ rorri ioe~ fnr ~ ~i~ri~nr+o
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01-I inrlin~~oe nnn,
Ordinance No. 6295
March 2, 2010 Page 8 of 43
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A. "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." The
area subject to the base flood is the Special Flood Hazard Area (SERA) desi Hated on
Flood Insurance Rate Maps as Zones "A," including AE, A0, AH, and Al-99.
B. "Base Flood Elevation" means the elevation of the base flood above the
datum of the effective FIRM.
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 Study for the City.
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 A0, the base flood elevation
shall be considered to be two feet above the highest grade adjacent to the structure.
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 roposed developments includin proposals for manufactured home arks
and subdivisions) greater than 50 lots or 5 acres, whichever is the lesser, shall include
such data with their permit applications. This data must be approved by the Floodplain
Administrator.
C. "Basement" means any area of the structure having its floor
subgrade (below ground level) on all sides.
D. "Channel Migration Area" means the area within the lateral extent of likely
stream channel movement due to stream bank destabilization and erosion, rapid stream
incision, and shifts in location of stream channels plus 50 feet.
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.
E. "Critical Facility" means a facility necessa 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).
F. "Development" means any manmade change to improved or unimproved
real estate, including but not limited to buildings or other structures, mining, dredging,
filling, grading, paving, excavation or drilling operations or storage of equipment or
Ordinance No. 6295
March 2, 2010 Page 9 of 43
materials -subdivision of land, removal of more than 5% of the native vegetation on the
property, or alteration of natural site characteristics.
G. "Dry Floodproofing" means any combination of structural and non
structural measures that prevent flood waters from entering a structure.
H. "Elevation Certificate" means the official form (FEMA Form 81-31 } used to
rovide elevation information necessary to ensure compliance with provisions of this
ordinance and determine the proper flood insurance premium rate.
I. "Equivalent Elevation" means having similar relationship to ordinary high
water and to the best available 10- ear, 50-year and 100-year water surface profiles;
J. "FEMA" means the Federal Emergency Management Agency, the agency
responsible for administering the National Flood Insurance Program.
K. "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).
L. "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; andlor
2. The unusual and rapid accumulation of runoff of surface waters from any
source.
!-!M. "Flood Insurance Rate Map (FIRM)" means the official map on which the
Federal Insurance Administration has delineated both the areas of special flood hazard
and the risk premium zones applicable to the community.
fN. "Flood Insurance Study" means the official report provided by the Federal
Insurance Administration that includes flood profiles, the Flood®Bo~;n !oodY^~ay
Insurance Rate Map, and the water surface elevation of the base flood.
0. "Flood Protection Elevation (FPE)" means the elevation above the datum
of the effective FIRM to which new and substantial) improved structures must be
protected from flood damage.
~P. "Floodway" means the channel of a stream or other watercourse and
the adjacent land areas that must be reserved in order to discharge the base flood
without cumulatively increasing the water surface elevation more than one foot. The
floodway shall be as delineated on the Flood Insurance Rate Map. Where floodwa 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 have not been provided, or 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 5 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 app) to applications for permits for small projects on lar,,,ge lots, such
as constructing a single family home.
Q. "Historic Structure" means a structure that:
1. Is listed on the National Register of Historic Places, the Washing ton
Heritage Register, or the Washington Heritage Barn Register, or has been designated a
Ordinance No. 6295
March 2, 2010 Page 10 of 43
landmark or been issued a Certificate of Appropriateness under the City's Historic
Preservation Ordinance.
2. Has been certified to contribute to the historical significance of a
registered historic district.
R. "Hyporheic Zone" means a saturated layer of rock or sediment beneath
andlor adjacent to a stream channel that contains some proportion of channel water or
that has been altered by channel water infiltration.
S. "Impervious Surface" means a hard surface area which causes water to
run off the surface in reater 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 as halt pavin ,gravel roads, packed earthen materials, and
oiled, macadam or other surfaces which similarly impede the natural infiltration of
stormwater.
!~T. "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 as that enclosure is not built so as to render the structure
in violation of the applicable nonelevation design requirements of this chapter found in
ACC 1.08.1?0,°,~?~ 15.68.170A~7~.
~U. "Manufactured home" means a structure, transportable in one or more
sections, which is built on a permanent chassis and is designed for use with or without a
permanent foundation when connected to the required utilities. For floodplain
management purposes, the term "manufactured home" also includes park trailers, travel
trailers, and other similar recreational vehicles placed on a site for greater than 180
consecutive days. For insurance purposes, the term "manufactured home" does not
include park trailers, travel trailers, and other similar recreational vehicles.
nnV. "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.
W. "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 ma , at applicant's ex ense, provide an appraisal to determine market
value.
X. "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.
Y. "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 providin ~ breeding and feedin,,, grounds for aquatic or ri arian s ecies.
"!Z. "New construction" means structures for which the "start of construction"
commenced on or after the effective date of the ordinance codified in this chapter.
AA. "Protected Area" means the lands that lie within the boundaries of the
floodway, the riparian habitat zone, and the channel migration area. In riverine areas,
Ordinance No. 6295
March 2, 2010 Page 11 of 43
where a floodway has not been designated in accordance with this Chapter, the
Protected Area is comprised of those lands that lie within the boundaries of the riparian
habitat zone, the channel migration area, and the SFHA.
~BB. "Recreational vehicle" means a vehicle:
1. Built on a single chassis;
2. Four hundred square feet or less when measured at the largest horizontal
projection;
3. Designed to be self-propelled or permanently towable by a light-duty truck;
and
4. Designed primarily not for use as a permanent dwelling but as temporary
living quarters for recreation, camping, travel, or seasonal use.
CC. "Re a, ulator 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.
DD. "Riparian" means of, adjacent to, or living on, the bank of a stream, lake,
pond, sound, or otherwater bod .
EE. "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 bod .The
riparian habitat zone includes the water body and adjacent lands, measured
perpendicularlvfrnm ordinar~r high water on both sides of the water body:
1. Marine and lake shorelines and Tvpe S streams that are designated
"shorelines of the State:" 250 feet.
2. Type F streams (fish bearing streams ,greater than 5 feet wide and marine
shorelines: 200 feet.
3. Type F streams less than 5 feet wide and lakes: 150 feet.
4. Ty e N nonsalmonid-bearings perennial and seasonal streams with
unstable slopes: 225 feet.
5. All other Tvpe N (nonsalmonid-bearing) perennial and seasonal streams:
150 feet.
In addition, the riparian habitat may zone include additional land areas that the
Floodplain Administratordetermines are like) to su port aquatic and riparian habitat.
FF. "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 a scientific and engineering report entitled "Flood Insurance
Study for the City of Auburn" dated May 16, 1995,and any revisions thereto, and
designated on Flood Insurance Rate Maps with the letters "A" including AE, A0, AH,
Al-99.
EGG. "Start of construction" includes substantial improvement, and means
dN±o N~;;!d;;; y^Ya ;ss~;°d; ~ °d t"e actual start of construction, repair,
reconstruction, addition, placement or other improvement ~^YUs Y^~;t"in ~0 uuys ^f
that occurred before the permit's expiration date. The actual start means
either the first placement of permanent construction of a structure on a site, such as the
pouring of slab or footings, the installation of piles, the construction of columns, or any
Ordinance No. 6295
March 2, 2010 Page 12 of 43
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 foundation or the erection
of temporary forms; nor does it include the installation on the property of accessory
buildings, such as garages or sheds not occupied as dwelling units or not part of the
main structure. For 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 notthat alteration affects the external dimensions of the building.
~HH. "Structure" means a walled and roofed building including a gas or liquid
storage tankthat is principally above ground.
II. "Substantial Damage: means damae~, a of an origin sustained b 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.
~RJJ. "Substantial improvement" or "substantially improved" means any repair,
reconstruction, addition, replacement or improvement of a structure, the cost of which
equals or exceeds 50 percent of the 1 market value of such structure
of+hor• ~.rlll lVl .
1 Rofnro fho imr~rn~iomonf nr ror»ir i~ ~~~r+orl• nr 1 L.JVIVI V ~I IV 1111`.!1 V Y V111V1 1~ VI I VL/ull IV VLUI ~Vbl, VI
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r»r~ of o hi iilrlin Enno~ ~nrhoor nr nn~ ~h~+ ~I~or~~in ffon~~ horn ~./NI ~ I<All l I IVVV, YYl lei 11{ell 4lILV16ALIVl IIVVLV LV111
uim~iiviviiv of t"° st; uctu; ° the "start of construction" of the improvement. This term
includes structures that have incurred "substantial damage," regardless of the actual
repairwork done.
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 ,nom
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 structure listed on the National Register of Historic
Places or a State Inventory of Historic Places.
~KK. "Variance" means a grant of relief from the requirements of this chapter
which permits construction in a manner that would otherwise be prohibited by this
chapter.
LL. "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 T inq classification system is herb adopted by
reference. The system defines fourwatertypes:
1. Type "S" =Shoreline: Streams that are designated "shorelines of the
State," including marine shorelines
Ordinance No. 6295
March 2, 2010 Page 13 of 43
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
MM. "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.
(a) A: SFHA where no base flood elevation is provided.
(b} A#: numbered A Zones ~e.q., A7 or A14}, SFHA with a base flood
elevation.
(c) AE: SFHA with a base flood elevation.
~d} A0: SFHA subject to inundation by shallow floodin~, usual) resultin.,~ from
sheet flow on sloping terrain, with average depths between one and three feet. Aver-
ageflood depths are shown.
(e) AH: SFHA subject to inundation by shallow flooding (usually areas of
onding} with average depths between one and three feet. Base flood elevations are
shown.
(fl 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 b a levee.
(q) 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 pondinq and local
drainage problems.
(h} D: area of undetermined butossible flood hazard.
(i) X: the area outside the mapped SFHA.
(i) Shaded X: the same as a Zone B, above. (Ord. 6161 § 1, 2008; Ord.
4820 § 1, 1995; Ord. 4357 § 2(2.1- 2.17), 1989.}
Article III. General Provisions
15.68.070 Land to which this chapter applies.
This chapter shall apply to the Regulatory Floodplain a!! areas of s~,oc;u! flood
within the jurisdiction of the city. (See whihi~ «o,„ ~ f+,^h°~ ~n ° nr~in~~~°
vv~.+ifi°v~ .n ±h~v vh~~~ar 'nom iiivvrn~nru~o~ horo~n Ny raforanvv°°~ the ctNfo ~Ivv~ (`nn~rnl
^n° City of Auburn Regulatory Floodplain Map on file in the Office of the city Clerk.
(Ord. 6161 § 1, 2008; Ord. 4820 § 1, 1995; Ord. 4357 § 2(3.1 1989.)
15.68.080 Reserved . Th° ~r°~e ~f ~No~~~l flnnrl h~~~rrl irl°n~ifi°rl h~i ±h° ~°rl°r~l Ines ir~nn°
Orlminiefr~finn in ~ er+i°n~ifir+ ~nrl °nnin°°rinn r°nnrf °nfi~l°rl "Th° ~Innrl Ines ir~nr+° Chi irl~i
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Ordinance No. 6295
March 2, 2010 Page 14 of 43
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15.68.090 Penalties for noncompliance.
No ,
development shall be undertaken without full compliance with the terms of
this chapter and other applicable regulations. Violation of the provisions of this chapter
by failure to comply with any of its requirements (including violations of conditions and
safeguards established in connection with conditions) shall be enforced pursuant to the
provisions of Chapter 1.25 ACC. (Ord. 6161 § 1, 2008; Ord. 4820 § 1, 1995; Ord. 4502
§ 20, 1991; Ord. 4357 § 2(3.3), 1989.}
15.68.100 Abrogation and greater restrictions.
This chapter is not intended to repeal, abrogate, or impair any existing
easements, covenants, or deed restrictions. However, where this chapter and another
ordinance, easement, covenant, or deed restriction conflict or overlap, whichever
imposes the more stringent restrictions shall prevail. (Ord. 6161 § 1, 2008; Ord. 4820 §
1, 1995; Ord. 4357 § 2(3.4), 1989.)
15.68.110 Interpretation.
In the interpretation and application of this chapter, all provisions shall be:
A. Considered as minimum requirements;
B. Liberally construed in favor of the governing body; and
C. Deemed neither to limit nor repeal any other powers granted under state
statutes.
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 provide on a
map. (Ord. 6161 § 1, 2008; Ord. 4820 § 1, 1995; Ord. 4357 § 2 (3.5), 1989.)
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 develo ment 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, nr ° ~°rl°r~l Ines ir~nr+° I~,rlminie~r~~inn~ for any damages to
property or habitat that results from reliance on this chapter or any administrative
Ordinance No. 6295
March 2, 2010 Page 15 of 43
decision lawfully made thereunder. (Ord. 6161 § 1, 2008; Ord. 4820 § 1, 1995; Ord.
4357 § 2(3.6), 1989.)
15.68.125 Appeals.
A. The Hearing Examiner shall hear and decide appeals and requests for
variances from the requirements of this chapter.
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 in the enforcement or administration of this chapter.
C. Those aggrieved by the decision of the Hearing Examiner may appeal
such decision to the Superior Court.
D. Upon consideration of the factors of this Chapter and the urposes of this
chapter, the Hearing Examiner may attach such conditions to the granting of variances
as it deems necessary to further the purposes of this chapter.
Article IV. Administration
15.68.130 Establishment of and requirement to obtain floodplain development permit.
A. A Floodplain development permit shall be obtained before construction or
development begins within the Regulatory Floodplainany ar°a ^f sNeo;a! f!^^d "ward
e in a innli irlinn • .The permit shall be for all
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IVI
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B. A development project is not subject to the requirements of this chapter if
it is located on land that can be shown to be
1. Outside the Protected Area and
2. Higher than the base flood elevation.
The floodplain administrator 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 from FEMA.
Ordinance No. 6295
March 2, 2010 Page 16 of 43
C. Non-Development Activities. Activities that do not meet the definition of
"development" in this chapter are allowed in the Regulatory Floodplain without the need
for a floodplain development permit under this chapter, provided all other Federal, State,
and local requirements are met. The following are examples of activities not considered
development or "man-made changes to improved or unimproved real estate."
1. Routine maintenance of landscaping that does not involve radin_c~
excavation, or filling;
2. Removal of noxious weeds and hazard trees and replacement of non-
native vegetation with native vegetation;
3. Normal maintenance of structures, such as re-roofing and replacing
sidin as long as such work does not qualify as a substantial improvement;
4. Normal maintenance of above round public utilities and facilities, such as
replacing downed power lines;
5. Normal street and road maintenance, including filling potholes, repaving,
and installing signs and traffic signals, but not including expansion of paved areas.
6. Normal maintenance of a levee or other flood control facility prescribed in
the operations and maintenance plan for the levee or flood control facilit ;and
Plowing and other normal farm practices (other than structures or filling)
on farms in existence as of the effective date of this ordinance.
D. Activities Allowed With a Floodplain Permit. The following activities are
allowed in the Regulatory Floodplain without the analysis required in Section
15.68.160C or the habitat impact assessment required under ACC 15.68.130K,
providing all other requirements of this ordinance are met, including obtaining a
floodplain development permit:
1. Repairs or remodeling of an existingq structure, provided that the re airs or
remodeling are not a substantial improvement or a repair of substantial damage.
2. Expansion of an existing structure that is no greater than ten percent
beyond its existin,~~ 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 this ordinance. If the structure is in the
floodway, there shall be no change in the dimensions perpendicularto flow.
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 Federal and State standards, provided the activities do not
include structures, grading, fill, or impervious surfaces.
4. Development of open space and recreational facilities, such as arks,
trails, and hunting grounds, that do not include structures, gradinq, fill, impervious
surfaces or removal of more than 5% of the native vegetation on the property.
E. Other Activities
All other activities not listed in 15.68.1306 or C are allowed, as long as they meet
all the other requirements of this ordinance, including the anal sis required in Section
15.68.160 and the habitat impact assessment and any mitigation required under Section
15.68.135E and Section 16.58.135K and a floodplain development permit is issued.
Ordinance No. 6295
March 2, 2010 Page 17 of 43
R pormi~ ' nr+o fnr flnnrl nnn nor hill r+nn ~ vvv ivi iivv~.+ vvi i Nt.~ ~ ~ ic..iii vvi i
Cor+finn 'Z of ~ i ihi irn (`ifv (lrrlin~nr+a nln /I 1 Q~ n~~~arJ nn I'lanomhar 1 F 1 QS2~ . (Ord. vvv~ivi i v vi i ~uN~.+i i i vi~y vi uii iui ivv i rv. ~ i vv Nuvvvu vii vvvvi i iwvi
i v, i vvv.
6161 § 1, 2008; Ord. 4820 § 1, 1995; Ord. 4357 § 2(4.1), 1989.)
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 elevations of the pro ert in
question,
2. Names and location of all lakes, water bodies, waterways and draina e
facilities within 300 feet of the site,
3. The elevations of the 10-, 50-, 100-, and 500-year floods, where the data
are available. Additionally, for property located within the SFHA, base flood elevations
for shall be included as required in ACC 15.68.060.8.3,
4. The boundaries of the Regulatory Floodplain, SFHA, floodwa ,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. Existin and roposed structures, fill, pavement and other im ervious
surfaces and sites for stora a of materials
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 roposed 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 and the proposed elevations of the following:
1. The top of bottom floor (including basement, crawlspace, or enclosure
floor)
2. The top of the next hi ,her 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
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 substantiall dammed 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 b a re,~~istered professional engineer or licensed
Ordinance No. 6295
March 2, 2010 Page 18 of 43
architect that the d floodroofinq methods meet the floodroofinq criteria in this
chapter.
E. The application shall include a description of the extent to which a stream,
lake, or other water bod ,including its shoreline, will be altered or relocated as a result
of the proposed development.
F. The application shall include documentation that the applicant has applied
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
occu anc~ will be issued onl if the applicant has received the required Federal, State,
and local permits.
G. The application shall include acknowledgment b the applicant that
representatives of and Federal, State or local unit of government with re,~~ ulatory
authority over the project are authorized to enter upon the property to inspect the
development.
H. If the project includes subdivision of land, the application shall include
acknowledgment that the applicant understands that the final certificate of occupancy
will be issued onl if the applicant has filed a Notice to Title recording the fact that art
of the property is in the SFHA, riparian habitat zone and/or channel migration area, as
appropriate.
I. The riparian habitat zone shall be delineated on the site plan b the
applicant at the time of application for sub-division approval or floodplain development
permit for all development proposals within 300 feet of any stream or shoreline.
J. If the project is located in the Regulatory Floodplain and includes activities
not listed in ACC 15.681308 and C, the application shall include a Habitat Impact
Assessment. If that Assessment determines that impacts would result from the ro~ect,
the a lication shall also include a Habitat Miti ation Plan.
K. Habitat Impact Assessment
Unless allowed under ACC 15.68.1308 or C, a ermit application to develo in
the Regulatory Floodplain shall include an assessment of the impact of the project on
water quality and aquatic and riparian habitat. The assessment shall be either:
1. A Biological Evaluation or Biological Assessment that has received
concurrence from the US Fish and Wildlife Service or the National Marine Fisheries
Service, pursuant to the Endan erect Species Act; or
2. An assessment prepared in accordance with Regional Guidance on
Floodplain Habitat Assessment and Mitigation, FEMA Region X, 2010. The assessment
shall deter-mine if the project would adversely impact:
(a) The primary constituent elements identified when a species is listed as
threatened or endangered,
(b) Essential Fish Habitat designated by the National Marine Fisheries
Service,
~ Fish and wildlife habitat conservation areas,
(d) Vegetation communities and habitat structures,
(e) Water quality,
Water quantity, including flood and low flow depths, volumes and
velocities,
Ordinance No. 6295
March 2, 2010 Page 19 of 43
(g) The channel's natural meandering attern,
(h) Spawning substrate, if applicable, and/or
(i) Floodplain refugia, if applicable.
L. Habitat Mitigation Plan
1. If the assessment conducted under ACC 15.68.135K concludes the
ro_~ect is expected to have an adverse impact on water quality and/or aquatic or
riparian habitat or habitat functions, the applicant shall provide a plan to mitigate those
impacts, in accordance with Regional Guidance on Floodplain Habitat Assessment and
Mitigation, FEMA Region X, 2010.
(a) If the project is located outside the Protected Area, the mitigation plan
shall include such avoidance, minimization, restoration, or compensation measures as
area propriate forthe situation.
(b) If the project is located in the Protected Area, the mitigation plan shall
include such avoidance, restoration, or compensation measures as are needed to
ensure that there is no net loss of habitat function due to the project. Minimization
measures are not allowed in the Protected Area, unless they, in combination with other
measures, result in no net loss of habitat function.
2. 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 com onents.
M. Third-Party Review.
For the habitat impact assessment required in ACC 15.68.135(K) or the habitat
mitigation plan required in ACC 15.68.135 (L), 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,__andlor 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 b a ualified consultant as defined in the Re Tonal Guidance Y
on Floodplain Habitat Assessment and Mitigation, FEMA Region X, 2010.
15.68.136 Floodplain Development Permit Ex iration.
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.
15.68.140 Designation of the Floodplain Administrator.2
The Director of Planning and Development, or the Director's designee, is hereby
appointed to administer and implement this Chapter by granting or denying floodplain
development permit applications in accordance with its provisions.
15.68.141 Duties of the Floodplain Administrator.
2 NOTE: The City Code Section 15.68.140, entitled Designation of the city of Auburn engineering division, was
repealed by Ord. 6161. (See also Ord. 4820 § 1,1995; Ord. 4357 § 2(4.2),1989.)
Ordinance No. 6295
March 2, 2010 Page 20 of 43
Duties of the floodplain administrator shall include, but not be limited to:
A. Review all floodplain development permits to determine that the permit
requirements of this ordinance have been satisfied.
B. Review all floodplain develo ment 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 required to assure compliance with the Endangered Species Act andlor other
appropriate State or Federal laws.
C. Review all floodplain develo ment permits to determine if the ro osed
development is located in the Protected Area. If located in the Protected Area, ensure
that the applicable provisions of this chapter are met.
D. Ensure that all development activities within the Re , ulator Flood lain of
the City meet the requirements of this 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 ublic inspection all records pertainin ~ to the provisions of this
chapter.
G. Submit reports as required for the National Flood Insurance Program.
H. Notify FEMA of an proposed amendments to this ordinance.
I. 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.
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 andground elevations).
15.68.150 Duties and responsibilities of the c;t;; v°iiyiiiv°v°i public works department.
Duties of the °e. Public Works Department regarding flood hazard
areas shall include, but not be limited to:
A. Permit Review.
1. Review all development permits to determine that the permit requirements
of this chapter have been satisfied;
2. Review all development permits to determine that all necessary permits
have been obtained from those federal, state or local governmental agencies from
which prior approval is required;
3. Review all development permits to determine if the proposed development
is located in the floodway. If located in the floodway, assure that the encroachment
provisions of ACC 15.68160C are met.
B. Use of Other Base Flood Data. When base flood elevation data has not
been provided in accordance with ACC 15.68.080, 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.
C. Information to Be Obtained and Maintained.
Ordinance No. 6295
March 2, 2010 Page 21 of 43
1. Where base flood elevation data is provided through the Flood Insurance
Study or required as in ACC 15.68.1506, 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.
2. For all new or substantially improved floodproofed structures:
~a Verify and record the actual elevation (in relation to mean sea level), and
fib- Maintain the floodproofing certifications required in ,°,CC 5.58.13' 0 ~,°,;;3;
this chapter.
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), professional engineer, currently licensed in the State of
Washington.
D. Alteration of Watercourses.
1. Notify adjacent communities and the Department of Ecology prior to any
alteration or relocation of a watercourse, and submit evidence of such notification to the
Federal Insurance Administration;
2. Require that maintenance is 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 of 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. 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 develo ment department.
Duties of the c;t;; N;~i!uiny d;~~ iviv"v Planning and Development Department eshall
include, but not be limited to:
A. Permit Review.
Ordinance No. 6295
March 2, 2010 Page 22 of 43
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(6} 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 A . 8-~~Athis
chapter;
3. Maintain for public inspection all building-related records pertaining to the
provisions of this chapter. (Ord. 6161 § 1, 2008.)
Article V. Provisions for Flood Hazard Protection
15.68.160 ~°n ' c~~n Standards of the ~~+y ~ enyinoo ~
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 higherthan the adjacent 100-year flood elevation.
5. All new development shall be designed and located to minimize the impact
on flood flows, flood storage, waterquality, and habitat.
(a) stormwater and drainage features shall incorporate low impact
development techniques that mimic pre-development 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 Re ulatory 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.
Ordinance No. 6295
March 2, 2010 Page 23 of 43
6. The site Ian 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
nei hborinq properties.
Utilities
(a) All new and replacement water supply systems shall be designed to
minimize or eliminate infiltration of flood waters into the s stems;
(b) Water wells shall be located outside the floodway and shall be protected
to the FPE;
~c) New and replacement sanitar sewa,~a, a systems shall be desi.~ ned to
minimize or eliminate infiltration of flood waters into the systems and discharges from
the systems into flood waters;
(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 ACC 15.68.135K as a condition of approval of an onsite
waste disposal system to be located in the Regulatory Floodplain.
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.
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C. Floodway Standards
1. In addition to the other requirements of this ordinance, a project to develop
in the floodway as delineated pursuant to this Chapter shall meet the followin criteria:
(a) The applicant shall provide a certification by a registered professional
engineer demonstrating through hydrologic and hydraulic analyses performed in accor-
dance with standard engineering 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 the ordinance.
(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
Ordinance No. 6295
March 2, 2010 Page 24 of 43
correct existing violations of State or local health, sanita , or safet 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 Re airs, replacement, reconstruction, or improvements to substantial)
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 b a re ~ istered professional engineer demonstratin ~ throw. h
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 Burin.,, the
occurrence of the base flood dischar~e by more than one foot. (Ord. 6161 § 1, 2008;
Ord. 4820 § 1, 1995; Ord. 4357 § 2(5.1), 1989.}
15.68.161 Standards of the
planning and develo ment de artment.
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 addition to other
anchoring requirements for resisting wind forces. (Reference FEMA's "Manufactured
Home Installation in Flood Hazard Areas"guidebookfor 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 andlor otherwise elevated or located so as
to prevent water from entering or accumulating within the components during conditions
of flooding.
Ordinance No. 6295
March 2, 2010 Page 25 of 43
C. Review of Building Permits. Where elevation data is not available either
through the Flood Insurance Study or from another authoritative source {~A~
,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 Ian required for development in the regulato 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 Re,~a, ulato 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 re uirement.
3. If the proposed project does not meet the criteria of this chapter, a habitat
impact assessment shall be conducted pursuant to ACC 15.68.135K and, if indicated by
that assessment, a habitat mitigation plan shall be prepared and implemented pursuant
to ACC 15.68.135L.e (Ord. 6161 § 1, 2008.)
15.68.170 SN°^;f;c additional standards of the city of auburn Nui!d;ny ui,v iviv
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.
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 orexceed 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;
Ordinance No. 6295
March 2, 2010 Page 26 of 43
~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 floodin_c
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 b a re~ istered professional en , ineer 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 eve square foot of enclosed area subject to floodin~~ shall be rovided.
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 either
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 t^y°t"°; V~;t" -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. 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 of this subsection based on
their development andlor 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
Ordinance No. 6295
March 2, 2010 Page 27 of 43
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 Al-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 ublic
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
Re , ulator~ 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 non-residential 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;
2. It is constructed and placed on the building site so as to offer minimum
resistance to the flow of floodwaters;
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-
resistantmaterials;
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;
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 Re ~ ulato Floodplain, all new
structures shall be located in that area.
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
Ordinance No. 6295
March 2, 2010 Page 28 of 43
the least impact on habitat b locating the structures as far from the water bod 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 ossible,
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 hi,,,gher. 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.
~ Access to and from the critical facilit shall be protected to the elevation of
the 500-year flood. (Ord. 6161 § 1, 2008; Ord. 4820 § 1, 1995; Ord. 4357 § 2(5.2),
1989. )
15.68.180 ~s Community Acknowledgement of FEMA Map
Amendments.
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1
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
Ordinance No. 6295
March 2, 2010 Page 29 of 43
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 Ch. I Federal Emergency
Management Agency or a request for exemption from fees as specified by Section 72.5
of 44 CFR Ch. I Federal Emergency Management Agency. Sections 72.3 and 72.5 of 44
CFR Ch. 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 Ch. I Federal Emergency Management
Agency. Section 65.6 of 44 CFR Ch. I Federal Emergency Management Agency is
herein adopted by reference in its entirety;
g. A request for floodway revision in accordance with the provisions of Section
65.7 of 44 CFR Ch. I Federal Emergency Management Agency. Section 65.7 of 44 CFR
Ch. 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, includine~, 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 com liance
with this ordinance.
(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:
1 The city's adoption of floodplain management ordinances incorporating
the increased base flood elevations andlor revised floodway reflecting the post-project
condition;
2 The city's submittal of evidence to the Federal Insurance Administrator of
the city's adoption of said revised floodplain management ordinances.
Ordinance No. 6295
March 2, 2010 Page 30 of 43
3. Within three months of completion of the proposed encroachments, the
developer shall be responsible for providing certified record drawings andlortechnical or
scientific data to the city for submittal to the Federal Insurance Administrator.
2. If an applicant disagrees with the re.,~, ulator~ data prescribed b 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 NFIP-ESA 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 NFIP-ESA
Hydrologic and Hydraulic Studies, FEMA Region X, 2010. If there is an 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. (Ord.
6161 § 1, 2008; Ord. 4820 § 1, 1995; Ord. 4357 § 2(5.3), 1989.}
15.68.190 Developments within areas of special flood hazard
Notwithstanding any other provision of this chapter, the city may permit
developments within areas of 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(D). (Ord. 6161 § 1, 2008; Ord. 4820 § 1, 1995; Ord. 4357 § 2(5.4}, 1989.)
15.68.200 Compensatory storage equipment.
A. Development proposals shall not reduce the effective base flood storage
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 connectto 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
wintertimelflood construction schedules; and
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.
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. (Ord. 6161 § 1, 2008.)
Ordinance No. 6295
March 2, 2010 Page 31 of 43
Section 3. Amendment to City Code. Section 16.10.010 of the Auburn
City Code be and the same hereby is amended to read as follows:
16.10.010 Purpose and intent.
A. The city of Auburn contains numerous areas that can be identified and
characterized as critical or environmentally sensitive. Such areas within the city include
wetlands, streams, wildlife habitat, significant trees, geologic hazards, ground water
protection areas, and flood hazards.
B. The city finds that these critical areas perform a variety of valuable and
beneficial biological and physical functions that benefit the city and its residents.
Alteration of certain critical areas may also pose a threat to public safety or to public and
private property or the environment. The city therefore finds that identification,
regulation and protection of critical areas are necessary to protect the public health,
safety and general welfare. The city further finds that the functions of critical areas and
the purpose of these regulations include the following:
1. Wetlands. Wetlands perform a variety of functions that include maintaining
water quality; storing and conveying storm water and flood water; recharging ground
water; providing important fish and wildlife habitat; and serve as areas for recreation,
education and scientific study, and aesthetic appreciation.
Wetland buffers serve to moderate runoff volume and flow rates; reduce
sediment, chemical nutrient and toxic pollutants; provide shading to maintain desirable
water temperatures; provide habitat for wildlife; and protect wetland resources from
harmful intrusion.
The primary goals of wetland regulation are to avoid adverse wetland impacts; to
achieve no net loss of wetland function and value -acreage may also be considered in
achieving the overall goal; to provide levels of protection that reflect the sensitivity of
individual wetlands and the intensity of proposed land uses; and to restore andlor
enhance existing wetlands, where possible.
2. Streams. Streams and their associated riparian corridors provide
important fish and wildlife habitat; help to maintain water quality; store and convey storm
water and flood water; recharge ground water; and serve as areas for recreation,
education and scientific study and aesthetic appreciation. Stream buffers serve to
moderate runoff volume and flow rates; reduce sediment, chemical nutrient and toxic
pollutants; provide shading to maintain desirable water temperatures; provide habitat for
wildlife; and protect stream resources from harmful intrusion.
The primary goals of stream regulation are to avoid adverse impacts to streams
and associated riparian corridors; to achieve no net loss of functions and values of the
larger ecosystem in which the stream is located; to protect fish and wildlife resources; to
protect water quality through appropriate management techniques; and, where possible,
to provide for stream enhancement and rehabilitation.
3. Wildlife Habitat. Wildlife habitat provides opportunities for food, cover,
nesting, breeding and movement for fish and wildlife; maintains and promotes diversity
of species and habitat; coordinates habitat protection with elements of the open space
system; helps to maintain air and water quality; helps control erosion; serves as areas
Ordinance No. 6295
March 2, 2010 Page 32 of 43
for recreation, education, scientific study, and aesthetic appreciation; and provides
neighborhood separation and visual diversity within urban areas.
The primary goals of wildlife habitat regulation are to avoid adverse impacts to
critical habitats for fish and wildlife; to achieve no net loss of functions and values of the
larger ecosystem in which the wildlife habitat is located; to implement the goals of the
Endangered Species Act; to promote connectivity between habitat areas to allow for
wildlife movement; to provide multi-purpose open space corridors; and where possible
to provide for fish and wildlife habitat enhancement and rehabilitation that reflect the
sensitivity of the species.
4. Ground Water Protection Areas. Ground water protection areas provide a
source of potable water and contribute to stream discharge/flow. Such areas contribute
to the recharge of aquifers, springs andlor wells and are susceptible to contamination of
water supplies through infiltration of pollutants through the soil.
The primary goals of ground water protection regulations are to protect ground
water quality by maintaining the quantity of recharge; avoiding or limiting land use
activities that pose potential risk of aquifer contamination; and to minimize or avoid
adverse impacts to ground water protection areas through the application of
performance standards, and to comply with the requirements of the Federal Safe
Drinking Water Act and Washington Administrative Code that require Group A public
watersystems to develop and implement a wellhead protection program.
5. Geologic Hazard Areas. Geologic hazard areas include lands or areas
characterized by geologic, hydrologic and topographic conditions that render them
susceptible to varying degrees of risk of landslides, erosion, seismic or volcanic activity.
The primary goals of regulating geologic hazards are to avoid and minimize
potential impacts to life and property by regulating andlor limiting land uses where
necessary, and to conduct appropriate levels of analysis and ensure sound engineering
and construction practices to address identified hazards.
6. Flood Hazard Areas. Floodplains help to store and convey storm water
and flood water; recharge ground water; provide important areas for riparian habitat;
and serve as areas for recreation, education, and scientific study. Development within
floodplain areas can be hazardous to those inhabiting such development, and to those
living upstream and downstream. Floods also cause substantial damage to public and
private property that results in significant costs to the public and individuals.
The primary goals of flood hazard regulations are to limit or condition
development within the a~ Regulatory Floodplain to avoid substantial
risk of damage to public and private property and that results in significant costs to the
public and individuals; to avoid significant increases in peak storm water flows or loss of
flood storage capacity; ~n~ ~ of o nr~fE 1lllill (`rooU ~Innrl
(`nn~rnl Ql~n if ~nrl ~nihon ~rlnr,+o~l to protect critical habitat for fish and wildlife, and to vvi iii vi i ic,~i i, ii w iu vvi ivi i uuvNw~.+
meet the purposes set forth in Chapter 15.68 of the Auburn City Code. Requirements
for the identification, assessment, alteration, and mitigation of flood hazard areas are
contained in Chapter 15.68 ACC.
The primary goals of flood hazard regulations are to limit or condition
development within the 100-year floodplain to avoid substantial risk of damage to public
and private property and that results in significant costs to the public and individuals; to
Ordinance No. 6295
March 2, 2010 Page 33 of 43
avoid significant increases in peak storm water flows or loss of flood storage capacity;
and to implement the objectives of the Draft Mill Creek Flood Control Plan, if and when
adopted.
C. This chapter of the Auburn City Code and other sections as incorporated
by reference contain standards, procedures, criteria and requirements intended to
identify, analyze, and mitigate potential impacts to the city's critical areas, and to
enhance and restore degraded resources where possible. The general intent of these
regulations is to avoid impacts to critical areas. Inappropriate circumstances, impacts to
specified critical areas resulting from regulated activities may be minimized, rectified,
reduced and/or compensated for, consistent with the requirements of this chapter.
D. It is the further intent of this chapter to:
1. Comply with the requirements of the Growth Management Act (Chapter
36.70A RCW) and implement rules to identify and protect critical areas and to perform
the review of development regulations required by RCW 36.70A.215;
2. Develop and implement a comprehensive, balanced and fair regulatory
program that avoids impacts to critical resources where possible, that requires that
mitigation be performed by those affecting critical areas, and that thereby protects the
public from injury, loss of life, property or financial losses due to flooding, erosion,
landslide, seismic events, soil subsidence, or steep slope failure;
3. Implement the goals and policies of the Auburn comprehensive plan,
including those pertaining to natural features and environmental protection, as well as
goals relating to land use, housing, economic development, transportation, and
adequate public facilities;
4. Serve as a basis for exercise of the city's substantive authority under the
State Environmental Policy Act (SEPA} and the city's environmental review procedures,
where necessary to supplement these regulations, while also reducing the city's reliance
on project-level SEPA review;
5. Provide consistent standards, criteria and procedures that will enable the
city to effectively manage and protect critical areas while accommodating the rights of
property owners to use their property in a reasonable manner;
6. Provide greater certainty to property owners regarding uses and activities
that are permitted, prohibited, and/or regulated due to the presence of critical areas;
Coordinate environmental review and permitting of proposals involving
critical areas with existing development review and approval processes to avoid
duplication and delay pursuant to the Regulatory Reform Act, Chapter 36.708 RCW;
8. Establish conservation and protection measures for threatened and
endangered fish species in compliance with the requirements of the Endangered
Species Act and the Growth Management Act requirements to preserve or enhance
anadromous fisheries, WAC 365-195-925;
9. Alert members of the public, including appraisers, assessors, owners,
potential buyers or lessees, to the development limitations of critical areas and their
required buffers.
E. Best Available Science. The city has considered and included the best
available science in developing these regulations, consistent with RCW 36.70A.172 and
WAC 365-195-900, et seq. This has been achieved through research and identification
Ordinance No. 6295
March 2, 2010 Page 34 of 43
of relevant technical sources of information, consultation with experts in the disciplines
covered by this chapter, and consultation and requests for technical information
regarding best available science from state and federal resource agencies.
Preparation of this chapter has included the use of relevant nonscientific
information, including consideration of legal, social, policy, economic, and land use
issues. This reflects the city's responsibilities under numerous laws and programs,
including other provisions of the Growth Management Act, and the need to weigh and
balance various factors as part of decision making to accomplish municipal objectives.
This may result in some risk to the functions and values of some critical areas. The city
will also use its authority under the State Environmental Policy Act (SEPA) to identify,
consider and mitigate, where appropriate, significant adverse effects on critical
resources not otherwise addressed by the regulations of this chapter.
The city intends to review and monitor implementation of its critical areas
regulations and to use an adaptive management approach. It will make adjustments to
the regulations, as appropriate, in response to changing conditions, new information
about best available science, or empirical data indicating the effectiveness of its
regulatory program. This will occur in the context of the city's ongoing review and
revision of its comprehensive plan and development regulations pursuant to the Growth
Management Act.
Additional information, both scientific and nonscientific, regarding compliance
with WAC 365-195-915(c), including identification of risks to resources, is contained in
the findings and conclusions and the overall record supporting adoption of Auburn's
critical areas regulations. (Ord. 5894 § 1, 2005.)
Section 4. Amendment to City Code. Section 16.10.070 of the Auburn
City Code be and the same hereby is amended to read as follows:
16.10.070 Critical area review process and application requirements.
A. Pre-Application Conference. Apre-application conference is available and
encouraged prior to submitting an application fora project permit.
B. Application Requirements.
1. Timing of Submittals. Concurrent with submittal of a State Environmental
Policy Act (SEPA) checklist, or concurrent with submittal of an application for projects
exempt from SEPA, a critical area report must be submitted to the city for review when
the city believes that a critical area may be present. The purpose of the report is to
determine the extent, characteristics and functions of any critical areas located on or
potentially affected by activities on a site where regulated activities are proposed. The
report will also be used by the city to determine the appropriate critical area
classification and, if applicable, to establish appropriate buffer requirements.
2. Report Contents. Reports and studies required to be submitted by this
chapter shall contain, at a minimum, the information indicated in the provisions of this
chapter applicable to each critical area. The director may tailor the information required
to reflect the complexity of the proposal and the sensitivity of critical areas that may
potentially be present.
Ordinance No. 6295
March 2, 2010 Page 35 of 43
C. Consultant Qualifications and City Review. All reports and studies required
of the applicant by this section 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:
1. The city has technical information that is unavailable to the applicant; or
2. The applicant has provided inaccurate or incomplete information on
previous proposals or proposals currently under consideration.
D. Review Process. This section is not intended to create a separate critical
area review permit for development proposals. To the extent possible, the city shall
consolidate and integrate the review and processing of critical area-related aspects of
proposals with other land use and environmental considerations and approvals. Any
permits required by separate codes or regulations, such as flood plain development
~nn° ^nn~r^' permits or shoreline substantial development permits, shall continue to be
required. (Ord. 5894 § 1, 2005.)
Section 5. Amendment to City Code. Section 17.04.300 of the Auburn
City Code be and the same hereby is amended to read as follows:
17.04.300 Regulatory floodway.
"Regulatory floodway" means ~h° nh~nn°I of ~ ri~i°r nr n °r ,n,~ ~n~ ~h°
r,r~lin~hl° In~i i QN±o nn~n Qnn~ „u~ the channel of a stream or NN""u""`' N 1 N•
other watercourse and the adjacent land areas that must be reserved in order to
discharge the base flood without cumulatively increasing the water surface elevation
more than one foot at any oint.
Section 6. Amendment to City Code. Section 17.09.050 of the Auburn
City Code be and the same hereby is amended to read as follows:
17.09.050 Development requirements.
A. Lot Area and Dimensions. Each lot created by short subdivision shall
contain sufficient square footage and lot dimensions to meet the requirements of ACC
Title 18. Each lot to be served by an on-site sewage disposal system shall be a
minimum of 15,000 square feet in area and shall also meet the minimum lot area
requirements of the county department of health rules and regulations. Land contained
in access easements, tracts or panhandles shall not be included in lot area or lot
dimension calculations for the purposes of this section.
B. Every lot within a short subdivision shall be capable of being reasonably
served by public or private sewage disposal, water, storm drainage facilities and streets.
The city will not approve a short subdivision for which a building permit cannot be
issued because of insufficient infrastructure.
Ordinance No. 6295
March 2, 2010 Page 36 of 43
C. Conformance with Adopted Plans. Street, water, sewer and storm
drainage facilities adjacent to or within the short subdivision shall be in conformance
with adopted city ordinances, standards and policies. Easements for utilities
recommended by such plans shall be provided to the city, with the exact location of
such easements to be determined by the city engineer.
D. Floods, Flood Control and Storm Drainage.
1. Where any portion of the proposed short subdivision lies within an area of
special flood hazard or regulatory floodway, conformance with adopted city flood hazard
area ordinances, standards and policies shall be required.
2. A conceptual storm drainagelsite grading plan shall be required to be
submitted, as part of the short subdivision application, unless waived by the city
engineer.
3. The proposed subdivision shall have one or more new lots in the Regulatory
Floodplain set aside for open space use through deed restriction, easement, subdivision
covenant, or donation to a public agency. The density of the development in the portion
of the development outside the Regulatory Floodplain may be increased in accordance
with applicable land use and subdivision re ulations.
4. If a parcel has a buildable site outside the Regulatory Floodplain, it shall not be
subdivided to create a new lot that does not have a buildable site outside the Regulatory
Floodplain. This provision does not apply to lots set aside from development and
preserved as open space.
E. Adjacent Streets. When any public street lying adjacent to the property
being short subdivided has insufficient width or for any other reason does not conform
to minimum street standards, in accordance with the city design and construction
standards, sufficient additional right-of-way shall be dedicated to the city and
appropriate improvements shall be made by the subdivider to conform the abutting half
of the street to such standards consistent with Chapter 12.64A ACC. Deferral of such
improvement requirements shall be in conformance with the city of Auburn design and
construction standards.
F. Access.
1. All short subdivisions shall border on an opened, constructed and maintained
public street. All lots within a short subdivision shall either border on an opened,
constructed and maintained public street or shall be served by a private street, access
easement, tract or panhandle having direct access to such a public street. Where
private streets and access easements are provided, they shall be improved or
guaranteed to the city of Auburn and be in conformance with the city of Auburn design
and construction standards.
2. All private streets, access easements and panhandles shall be capable of
meeting the fire access requirements of Chapter 15.36A ACC and the development
standards of Chapters 17.14 and 18.31 ACC, in addition to any other requirements of
this title, including, but not limited to, an adequate surface for access and minimum
turnaround requirements on dead-end streets or access easements as specified by the
fire department.
Ordinance No. 6295
March 2, 2010 Page 37 of 43
3. All roposals shall ensure that all buildable lots shall have at least one access
road connected to land outside the Regulatory Floodplain with the surface of the road at
or above the FPE.
G. Dedication of Streets. Dedication of a public street or streets may be
required, whenever the city engineer finds that one or more of the following conditions
applies:
1. The general alignment of a proposed private street, access easement or
panhandle follows the general alignment of a future arterial as shown in the
comprehensive plan; or
2. The general alignment of a proposed private street, access easement or
panhandle can be reasonably modified to provide a desirable through-connection
between two or more existing or planned public streets or arterials; or
3. A public street would be necessary to provide adequate access to
adjacent property not subject to the proposed short subdivision.
H. Fire Hydrants. All lots within a short subdivision shall be capable of being
served by a fire hydrant as required by Chapter 13.16 ACC. Property zoned RC,
residential conservancy, may be exempt, provided the requirements of ACC 13.16.030
are met. (Ord. 6239 § 1, 2009; Ord. 6186 § 12, 2008; Ord. 6006 § 3, 2006. Formerly
17.14.055)
Section Amendment to City Code. Section 17.14.110 of the Auburn
City Code be and the same hereby is amended to read as follows:
17.14.110 Floods and flood control.
The city may disapprove a proposed subdivision because of flood, inundation or
swamp condition if the city finds that such condition poses a threat to the public health,
safety or general welfare or causes a public nuisance.
Where any portion of the proposed subdivision lies within the u; eu of sNe^;u! f!oou
Regulatory Floodplain, the hearing examiner shall impose a
condition on the preliminary plat requiring the subdivider to conform to the city's f!~~u
h~~~rrl ,roe Floodplain Development requirements as set forth in Chapter 15.68 of the
Auburn Cit Code. In such cases, no development permit associated with the proposed
subdivision shall be issued by the city until said flood hazard area regulations have
been met.
The city may require dedication of land to any public body and/or the construction
of improvements and may impose other conditions necessary to protect against flooding
or inundation.
Section 8. New Section to City Code. Section 17.04.305 of the Auburn
City Code be and the same hereby is created to read as follows:
17.04.305 Regulatory Floodplain.
"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
Ordinance No. 6295
March 2, 2010 Page 38 of 43
Flood Hazard Areas and Protected Areas that are delineated pursuant to City
Ordinance.
Section 9. New Section to City Code. Section 17.04.335 of the Auburn
City Code be and the same hereby is created to read as follows:
17.04.335 Special Flood Hazard Area.
"Special Flood Hazard Area (SERA)" means the land subject to inundation by the
base flood. Special Flood Hazard Areas are identified by the Federal Emergency
Management Agency in a scientific and engineering report entitled "Flood Insurance
Study for the City of Auburn" dated May 16, 1995,and any revisions thereto, and
designated on Flood Insurance Rate Maps with the letters "A" including AE, A0, AH,
Al-99.
Section 10. Amendment to City Code. A New Section 18.70.025 of the
Auburn City Code be and the same hereby is created to read as follows:
18.70.025 Variances in Regulatory Floodplains
A. Subject to conditions, safeguards and procedures provided by this section,
the hearing examiner may be empowered to hear and decide applications for variances
from the terms of Chapter 15.68; provided the hearing examiner may approve a
variance only if the request conforms to all of the criteria in ACC 18.70.025.6. 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 dangerto life and property due to flooding or erosion damage;
2. The danger that materials may be swept onto other lands to the injury of
others;
3. The safety of access to the property in times of flood for ordinary and
emergency vehicles;
4. The expected heights, velocity, duration, rate of rise, and sediment
transport of the flood waters and the effects of wave action, if applicable, expected at
the site;
5. The susceptibility of the proposed facility and its contents to flood or
erosion damage and the effect of such damage on the individual owner;
6. The availability of alternative locations for the pro-posed use which are not
subject to flooding or channel migration and are not in designated fish and wildlife
habitat conservation areas;
The relationship of the proposed use to the comprehensive plan, growth
management regulations, and flood-plain management program for that area;
8. The costs of providing governmental services during and after flood
conditions, including maintenance and repair of public utilities and facilities such as
sewer, gas, electrical, and water systems, and streets and bridges;
Ordinance No. 6295
March 2, 2010 Page 39 of 43
9. The potential of the proposed development project to destroy or adversely
modify a fish and wildlife habitat conservation area; and
10. The potential of the proposed development project to affect, or be affected
by, channel migration; and
11. Shall not result in a violation of this ordinance.
B. The examiner must enter findings of fact and conclusions of law which
support the following criteria and any conditions. No variance shall be granted to the
requirements of Chapter 15.68 ACC unless the applicant demonstrates that:
1. The development project cannot be located outside the Regulatory
Floodplain;
2. An exceptional hardship would result if the variance were not granted;
3. The relief requested is the minimum necessary;
4. The applicant's circumstances are unique and do not represent a problem
faced by other area properties;
5. If the project is within a designated floodway, no increase in flood levels
during the base flood discharge would result;
6. The project will not adversely affect fish or wildlife habitat;
If the issue is not specific to the property, but is a problem faced by other
properties, the remedy should be a revision to the ordinance ratherthan a variance.
There will be no additional threat to public health, safety, beneficial stream
orwater uses and functions, or creation of a nuisance;
8. There will be no additional public expense for flood protection, lost
environmental functions, rescue or relief operations, policing, or repairs to streambeds,
shorelines, banks, roads, utilities, or other public facilities; and
9. All requirements of other permitting agencies will still be met.
C. Variances requested in connection with restoration of a historic site,
building or structure may be granted using criteria more permissive than the above
requirements, provided:
1. The repair or rehabilitation is the minimum necessary to preserve the
historic character and design of the site, building or structure; and
2. The repair or rehabilitation will not result in the site, building or structure
losing its historic designation.
D. Variances to the provisions of ACC 15.68.161 and 15.68.170 may be
issued for a structure on a small or irregularly shaped lot contiguous to and surrounded
by lots with existing structures constructed below the FPE, providing the other variance
criteria are met. The applicant for such a variance shall be notified, in writing, that the
structure (i) will be subject to increased premium rates for flood insurance up to
amounts as high as $25 for $100 of insurance coverage and (ii) such construction below
the FPE in-creases risks to life and property. Such notification shall be maintained with
a record of all variance actions.
E. Variances pertain to a physical piece of property. They are not personal in
nature and are not based on the inhabitants or their health, economic, or financial
circumstances.
Ordinance No. 6295
March 2, 2010 Page 40 of 43
Section 11. Repeal of Section of City Code. Section 17.04.045 of the
Auburn City Code (Definitions -Area of special flood hazard.) is repealed in its entirety.
TEXT OF REPEALED SECTION
17.04.045 Area of special flood hazard.
"Area of special flood hazard" means the land within the floodplain in a
community subject to a one percent or greater chance of flooding in any given
year, as indicated in the Flood Insurance Rate Map (FIRM) program entitled
Flood Boundary and Floodway Map. (Ord. 6239 § 1, 2009.)
Section 12. Incorporation of Guidelines. The "Regional Guidance
for Floodplain Habitat Assessment and Mitigation", developed by the Federal
Emergency Management Agency drafted and dated January 1, 2010, and any
subsequent amendments or versions promulgated by the Federal Emergency
Management Agency, and the "Regional Guidance for NFIP-ESA Hydrologic and
Hydraulic Studies, developed by the Federal Emergency Management Agency drafted
and dated January 1, 2010, and any subsequent amendments or versions promulgated
by the Federal Emergency Management Agency shall be on file with the City Clerk, and
incorporated herein by this reference, for use in connection herewith.
Section 13. Ministerial Corrections. The Code Reviser is authorized
and direct to change all references to "Flood Control Zone Permits" in the Auburn City
Code to "Floodplain Development Permit."
Section 14. Repeal of Moratorium. The moratorium on the filing, receipt,
and approval of applications for development in the floodplain created by Resolution
4416 and extended by Resolutions 4442, 4476, and 4535 is hereby terminated as of the
effective date of this Ordinance.
Ordinance No. 6295
March 2, 2010 Page 41 of 43
Section 15. Fee schedule. The City of Auburn Fee Schedule shall be
amended to include the following fees:
Planning Department Fees
Floodplain development permit (when other City of Auburn development permits
required) $0
Floodplain development permit (stand alone permit; no other City of Auburn
development permits required) $50.00
Habitat Impact Assessment Report Review Fee (stand alone submittal) $250.00
Habitat Mitigation Plan Review Fee (stand alone submittal) $250.00
Combined Habitat Impact Assessment /Mitigation Plan Review Fee $500.00
and shall be further amended to delete the following fee:
Public Works Department Fees
6. Flood Control Zone Permit: (Per Ordinance No. 5819)
Base permit fee $50.00
The City Clerk is authorized to insert the above fees into the City of Auburn Fee
Schedule without any further action by the City Council.
Section 16. Implementation. The Mayor is hereby authorized to implement
such administrative procedures as may be necessary to carry out the directions of this
legislation. This authority specifically includes making non-substantive changes to the
municipal code sections amended in this ordinance in order to comply with the direction
of the federal agencies reviewing this ordinance.
Section 17. Severability. The provisions of this Ordinance are
declared to be separate and severable. The invalidity of any clause, sentence,
Ordinance No. 6295
March 2, 2010 Page 42 of 43
paragraph, subdivision, section or portion of this ordinance, or the invalidity of the
application thereof to any person or circumstance shall not affect the validity of the
remainder of this ordinance, or the validity of its application to other persons or
circumstances.
Section 18. Effective date. This Ordinance shall take effect and be in force
as interim regulations five days from and after its passage, approval and publication as
provided by law. If the City receives approval of the ordinance from the federal
agencies, provisions herein shall automatically be effective as permanent regulations,
with the effective date the same as the effective date of the interim regulations.
INTRODUCED:
PASSED:
APPROVED:
CITY OF AUBURN
PETER B. LEWIS
MAYO R ATTEST:
Danielle E. Daskam, City Clerk
APPROVED AS TO FORM:
Daniel B. Heid, City Attorney
Published:
Ordinance No. 6295
March 2, 2010 Page 43 of 43
Draf t
City of Auburn
Regulatory Floodplain
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DRAFT
Regional Guidance for
Floodplain Habitat Assessment and Mitigation
Contents
Introduction l
Background l
Definitions l
When to Conduct a Habitat Assessment 2
Allowed Activities 4
Conducting the Assessment 6
Step 1. Describe the Proj ect Area 6
l.l. Project Area Description 6
1.2. Project Area Map 7
Step 2. Describe the Proj ect Area's Habitat 8
2.1. Background Research 8
2.2. Protected Species Identification 8
2.3. Site Investigation .......................................................................................10
2.4. Habitat Narrative ........................................................................................11
2.5. Habitat Area Map .......................................................................................12
Step 3 . Describe the Project ..................................................................................12
3.1. Final Project ...............................................................................................13
3.2. Construction Process ..................................................................................13
3.3. Protection Measures ...................................................................................14
Step 4. Assess the Impact ......................................................................................14
4.1. Types of Impacts ........................................................................................15
4.2. Report Format ............................................................................................16
4.3. Effects Determination ................................................................................17
4.4. Assessment Report .....................................................................................17
Habitat Assessment and Mitigation - i - January 1, 2010 DRAFT
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Preparing the Mitigation Plan ...............................................................................18
Step 5. Review Mitigation Alternatives (Mitigation Sequencing) ........................18
5.1. Avoidance ..................................................................................................18
5.2. Minimization ..............................................................................................19
5.3 . Restoration 20
5.4. Compensation 20
5.5. Select the Best Approach(es) 21
Step 6. Prepare the Mitigation Plan 22
6. l .Objective 22
6.2. Format 22
6.3. Minimum Standards 23
Reviewing Habitat Assessments and Mitigation Plans 24
References and Resources 25
Federal and State Regulations 25
Maps and Databases 25
Water Quality and Quantity 26
Mitigation 26
Additional References 27
Habitat Assessment and Mitigation - ii - January 1, 2010 DRAFT
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Acknowledgements
This guidance document was developed by Region X of the Federal Emergency
Management Agency, as part of its continuing effort to improve floodplain
management practices and assist communities in meeting the requirements of the
Endangered Species Act.
It was prepared with the advice and assistance of a special advisory committee
that included representatives from:
- City of Auburn
- City of Carnation
- City of Everett
- Jefferson County
- King County
- City of Lacey
- Lummi Nation
- City of Monroe
- Pierce County
- Snohomish County
- City of Tukwila
- Washington State Department of Ecology
- Whatcom County
This document was drafted by French & Associates, Ltd., Steilacoom, ESA
Adolfson, Seattle, and PBS&J, Seattle, through an arrangement with the Insurance
Services Office and the Community Rating System.
Habitat Assessment and Mitigation -iii - January 1, 2010 DRAFT
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Habitat Assessment and Mitigation - iv - January 1, 2010 DRAFT
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Introduction
Background
This Regional Guidance is written for communities in the Puget Sound Basin. It will assist them
in meeting the requirements and criteria of the Endangered Species Act (ESA) as clarified in the
Biological Opinion issued by the National Marine Fisheries Service (NMFS) on September 22,
2008. This Regional Guidance is intended for environmental planners, wildlife, Foodplain,
stream, and wetland scientists, and other qualified habitat professionals.
This document is designed to support the NFIP-ESA Model Ordinance, which was also prepared
by FEMA Region X. The Model Ordinance includes a Biological Opinion Checklist which
provides a summary of what is required of communities by the Endangered Species Act. For
further details on the Biological Opinion's requirements, see the Model Ordinance Introduction
section and the Biological Opinion text in Appendix E of the Model Ordinance.
Communities have the option of adopting the Model Ordinance or ensuring that their existing
regulations fulfill all the Biological Opinion's requirements. Sections in the Model Ordinance are
referenced in this guidance to help the reader match the requirements with the Biological
Opinion and NFIP regulations. Additional references included in this assessment are listed at the
end of the document.
This guidance was prepared with technical input from local officials, engineers, natural resources
scientists, and planners. It is designed to assist qualified habitat professionals, representing both
permit applicants and permit officials to ensure that new development will not adversely impact
the habitat of protected threatened and endangered species in floodprone areas, including those
areas associated with stream, lake, and marine water bodies.
Although the Biological Opinion addresses ESA listed salmonid species and Southern Resident
killer whales, the Model Ordinance and this guidance were developed to address potential
impacts to all ESA listed species.
Definitions
Four terms are used in this guidance and the Model Ordinance that may not be the same terms
used in a community's regulations: "Regulatory Floodplain", "Special Flood Hazard Area" (or
"SFHA"), "Protected Area," and "development." These terms are introduced in the Definitions
section of the Model Ordinance (Section 2). The first three are defined in more detail in Sections
3.1, 3.2 and 3.4 of the Model Ordinance.
The Regulatory Floodplain is comprised of the SFHA and the Protected Areas, where:
• The SFHA is the area subject to flooding by the base flood (as determined and mapped
for each community by FEMA within flood insurance studies and accompanying Flood
Insurance Rate Maps (FIRMS)); and
Habitat Assessment and Mitigation -1- January 1, 2010 DRAFT
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• The Protected Area is comprised of those lands that lie within the boundaries of the
floodway, the riparian habitat zone, and the channel migration area.
An example of how the Regulatory Floodplain, SFHA, and Protected Area interrelate is shown
on the next page. A community's ordinance may use a different term to delineate the same or a
larger area in order to reach the same objective of addressing adverse impacts to aquatic and
riparian habitat in the most sensitive areas. However, as these terms are used throughout this
guidance, please refer to the full definitions included in Sections 2 and 3 of the Model Ordinance
in order to ensure full consistency with the Biological Opinion.
A fourth term is also used throughout this document. In Section 2, the Model Ordinance defines
"development" as
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,
storage of equipment or materials, subdivision of land, removal of more than 5% of the native
vegetation on the property, or alteration of natural site characteristics.
When to Conduct a Habitat Assessment
whenever a development project is proposed in the Regulatory Floodplain, the property owner
must obtain a floodplain development permit from the community (Section 4.1). Certain types of
projects can be permitted relatively quickly (see "Allowed Activities" on page 4). Applicants for
projects that are not listed as exempt from conducting a habitat assessment by the community's
floodplain management ordinance must assess the impact of the proposed development on
flooding and habitat.
An adverse impact on flooding is prevented through the ordinance requirements for a floodway
or encroachment analysis (Section 7.5) and compensatory storage (Section 7.6).
The impact of a proj ect on habitat is more complicated because there is often little or no
information on the site's natural features and different projects will have different impacts.
Therefore a habitat assessment is needed to identify those features and determine how the
proposed project will affect them (Section in the Model Ordinance).
There are only two circumstances where a habitat assessment would not be required:
1. Projects that are listed as exempt from conducting a habitat assessment in the
community's floodplain management ordinance; and
2. Projects that have undergone Section 7 consultation under the Endangered Species Act
(ESA) in order to obtain a federal permit.
It should be noted that projects requiring a federal permit under Section 404 of the Clean Water
Act would likely need a consultation process through the U.S. Army Corps of Engineers Regula-
tory Branch, the US Fish and wildlife Service (USFWS), and/or NMFS. Such consultation is
required under Section 7 of the ESA.
Habitat Assessment and Mitigation - 2 - January 1, 2010 DRAFT
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Special flood Haiard Area and Floodway Channel Migration Area Riparian Nabitat Zone
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This graphic shows the relative locations of the floodway, riparian habitat zone, and the channel migration area, the
determinants of the Protected Area. The Regulatory Floodplain includes all of the SFHA and all of the Protected Area.
Enforcing the ordinance throughout the Regulatory Floodplain is needed to comply with the Endangered Species Act.
A community can receive CRS credit if the Regulatory Floodplain extends beyond the SFHA.
Source: Pierce County, 2007, GeoEngineers, 2005; USDA, 2006 (Air Photo)
Habitat Assessment and Mi[igation - 3- January I, 2010 DRAFT
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If a permit applicant has prepared a Biological Evaluation or a Biological Assessment and has
received concurrence from USFWS or NMFS, the project is deemed to comply with the ESA. In
such cases, the additional habitat assessment requirements of this guidance are not required (see
Section 7.7.A of the Model Ordinance).
Once it is determined that a habitat assessment is needed, a step by step assessment process is
recommended in this guidance. This process is summarized in the flow chart on the following
page. Steps 1- 4 comprise the basic habitat assessment.
If the assessment finds an adverse impact, then the permit applicant must prepare a plan that
identifies steps the permit applicant will take to mitigate that impact (Section 7.8 in the Model
Ordinance and Steps 5 - 6 in this document) and must implement the mitigation plan.
It is recommended that applicants start with conceptual development plans and conduct a
preliminary impact assessment before they invest in detailed project plans and specifications.
Continued communication with community staff will also help identify problems and solutions
before too much time and/or money is spent on a proj ect that may require additional mitigation
measures.
A permit applicant should weigh the cost needed to prepare the assessment and the mitigation
plan, should one be needed, against the cost of locating the proj ect outside the Regulatory
Floodplain. It may cost less in time and money to simply avoid the SFHA, the Protected Area, or
their most sensitive areas.
Allowed Activities
A habitat assessment is not needed if it is not required for certain activities, as specified by the
community's Foodplain management ordinance. The Model Ordinance, in Sections 7.1 and 7.2,
identifies two types of activities that can proceed without the habitat assessment. The reader
must check the community's flood management ordinance because it may have a slightly
different list.
Section 7.1 of the Model Ordinance clarifies that some activities are not considered
"development" and therefore do not need a Foodplain development permit, provided all other
State and local requirements are met. An example would be normal maintenance of structures,
such as re-roofing and replacing siding. The Model Ordinance's list is not included here, because
the community's list maybe different.
Section 7.2 of the Model Ordinance lists other activities which are allowed in the Regulatory
Floodplain without the floodway analysis or the habitat impact assessment required under
Sections 7.5 and providing they meet all the community's other requirements and a
Foodplain development permit is issued. Again, the Model Ordinance's list is not included here,
because the community's list maybe different and takes precedence.
Habitat Assessment and Mitigation - 4 - January 1, 2010 DRAFT
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1s the project in the
Regulated Floodplain?
YES ~ NO
~
Has a Biologrcal Evaluation been prepared
for the p~oject'and have fVMFS and/or USFWS
detemirned concurr;ence with the, project
under Section 7 of the ESA?
t-YES-~
I
NO
~
!s the developineirt project
an allowed activity?
ConAUCtthaAssessment ~ I-YES~,
Step 1: Deseribe the ProjectArea • NO
Step 2:'Desoritie the Habitat
Step 3: Describe the Projecl Step 4: A§ses§ tfieJmpact
Wi(1 the project cause.
. an advers'e impact?
. . . t-~.
'Prepare the Mitigation'Plan i, NO
'Step S Re'view Mitigation Altematives YES
Step 6; Prepare the Mitlgation'Plan Redesign.the projecf
to incorporate the plan's,
mifigation measures
Is the plan acceptable? YES
I
-N i O
~
Redesign the project or Procee8 witFi theproject,
the mitigation measures getting all required permits
Habitat Assessment Flow Chart
Habitat Assessment and Mitigation ' - 5- January 1, 2010 DRAFT
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Conducting the Assessment
The following steps should be taken to adequately identify and address the impacts a proposed
project may have on habitat within the Regulatory Floodplain. In circumstances where an
approved habitat assessment (Steps 1 through 4) determines that no impacts to habitats
associated with ESA listed species will occur, development of a mitigation plan is not necessary.
However, for any activity requiring a habitat assessment within the Regulatory Floodplain, it is highly likely that impacts to habitats associated with ESA listed species will occur.
When habitat
impacts are identified, a mitigation plan must be prepared for the project, in accordance with
Steps 5 and 6.
Step 1. Describe the Project Area
The project area is generally the parcel being developed. In some cases, the project may extend
to a larger area, such as when a road to the parcel is to be built or improved. Step 1 should
produce two documents:
1.1. Project Area Description
If a Washington State Joint Aquatic Resources Permit Application (DARPA) form has been
prepared for the project, it will include all the project area description information needed for the
habitat assessment. The Washington State DARPA form template can be found at:
www.nws.usace.army.mil/PublicMenu/Menu.cfm?sitename=REG&pagename=Home_Page
If the information is already being provided in a Washington State DARPA, the community may
accept the application form as sufficient for the project area description. If a Washington State
DARPA has not been prepared for the project, the project area description should include the
following information:
- Location information:
o Street address
o City and County
o Township, section, and range
o Latitude and longitude
o Tax parcel number(s) of the proj ect location
o Type of ownership of the project (Federal, State, or locally owned public lands; tribal
lands; privately owned lands)
- Water resource information:
o Watershed name
o Water resource inventory area (WRIA). Information on Puget Sound basin WRIAs can be found at the Washington State Department of Ecology's watershed planning
webpage (http://www.ecy.wa.gov/watershed/index.html) and mapping webpage
(http://www.ecy.wa.gov/services/gis/maps/wria/wria.htm)
Habitat Assessment and Mitigation - 6 - January 1, 2010 DRAFT
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o Water bodies in which work will occur, including water typing. For more information
on water typing and a map that designates the types for major water bodies, see the
Washington State Department of Natural Resources water typing webpage
(www.dnr.wa.gov/BusinessPermits/Topics/ForestPracticesApplications/Pages/fp_wat
ertyping.aspx)
o Water bodies bordering or adj acent to the proj ect location, including water typing.
o Shoreline Management Areas associated with shorelines of the state, as managed by
the State Shoreline Management Act and local Shoreline Master Programs. Shoreline
Management Area information should include the Shoreline Environment designation
and a description of the approximate extent of jurisdiction. To identify associated
Shoreline Management Areas and Shoreline Environment designations, review the
jurisdiction's Shoreline Master Program and contact the local permitting official.
- Fish and Wildlife Habitat Conservation Areas (name and short description). Fish and
Wildlife Habitat Conservation Areas are designated by local governments pursuant to the
Growth Management Act. They should include waters of the state (i.e., Type S streams
and shorelines), habitats for species that are endangered or threatened (including
designated critical habitats and areas where the presence of listed species is documented),
habitats for species of local importance, and natural area preserves. The community
should have a list of designated Fish and Wildlife Habitat Conservation Areas and/or
criteria for designating them.
1.2. Project Area Map
The second item needed for Step 1 is a map, drawn to scale that delineates the following:
- Parcel boundaries
- Area of the finished project (including roads)
- Any additional area(s) that will be disrupted during construction (including access routes,
staging areas, and areas to be re-graded or filled)
- All water bodies
- Fish and Wildlife Habitat Conservation Areas
- Existing native vegetation by vegetation community zones. For example, a map could
distinguish areas with existing coniferous forest cover vs. areas with existing shrub cover
vs. areas with existing meadow cover.
- Boundaries of the following regulatory areas (see Section 3 of the Model Ordinance)
o Special Flood Hazard Area
o Floodway
o Riparian habitat zone
o Channel migration area
- Depths of the 10 and 100-year floods at representative locations. This need only be
provided where flood data are available from existing studies or the community.
Habitat Assessment and Mitigation - 7 - January 1, 2010 DRAFT
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Step 2. Describe the Project Area's Habitat
During Step 2 of the habitat assessment, the applicant describes the existing habitat conditions of
the project area. Tasks 2.1 and 2.2 of Step 2 are largely based on existing scientific information
on the species use and habitat in the project vicinity.
2.1. Background Research
Step 2 should start with an examination of existing sources of information relevant to threatened
or endangered species and their habitats in or near the project area. There may be thorough inventories already available. The following sources should be checked:
- The community's planning or environmental protection department for critical areas
inventory maps, best available science consistency studies, designated Fish and Wildlife
Habitat Conservation Areas, and watershed and habitat studies
- The community's parks and/or natural resources departments for natural area studies
- National Marine Fisheries Service critical habitat maps
(www.nmfs.noaa. gov/pr/species/criticalhabitat.htm)
- US Fish and Wildlife Service (critical habitat maps (http://criticalhabitat.fws.gov/)
- USFWS National Wetland Inventory maps (www.fws.gov/wetlands/)
- USFWS and NMFS habitat recovery plans, when published for ESA listed species in the
proj ect vicinity
o USFWS: www.fws.gov/pacific
o NMFS: www.nwr.noaa.gov
- US Department of Agriculture, Natural Resource Conservation Service soil survey maps
(http://websoilsurvey.nres.usda.gov/app/)
- Washington Department of Fish and Wildlife Priority Habitats and Species Database
(http://wdfw.wa.gov/hab/phslist.htm)
- Washington State Department of Ecology Water Quality Assessment
(www.ecy.wa.gov/programs/wq/303d/2008/index.html)
2.2. Protected Species Identification
The review of the existing research should identify all federally-listed species and designated
critical habitats, Essential Fish Habitat (EFH, defined by the Magnuson-Stevens Fishery
Conservation and Management Act) and affected EFH species, and Fish and Wildlife Habitat
Conservation Areas in, overlapping, or within 200 feet of the project area. The table on the next
page is an example of how this information could be presented.
To determine what listed or proposed species and EFH may occur in the action area, check with
NMFS (www.nwr.noaa.gov) and the USFWS (www.fws.gov/westwafwo/speciesmap.html) to
obtain a county list of federally listed/designated and proposed species and critical habitat.
Habitat Assessment and Mitigation - 8 - January 1, 2010 DRAFT
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Occurrence of Listed Species and Critical Habitat in or Nearthe Project Area.
Critical
Habitat Common Name Scientific Name ESA Status Jurisdiction Present
Puget Sound Evolutionarily Oncorhynchus Threatened NMFS Yes Significant Unit (ESU) tshawytscha
Chinook Salmon
Puget Sound Distinct 0. mykiss Threatened NMFS None
Population Segment (DPS)
Steelhead
Coastal-Puget Sound DPS Salvelinus Threatened USFWS Yes
Bull Trout confluentus
EFH species to be considered in freshwater systems commonly include three species of Pacific
salmon: pink, coho and Chinook salmon. If the project area includes estuarine and marine
systems, numerous species of groundfish and coastal pelagic fishes may also need to be
consl ere .
This task should summarize the biological and ecological information that will be needed for the
habitat assessment. Appropriate information on the species' life history, its habitat and
distribution, and other data on factors necessary to its survival, should be included to provide
background for analyses in later sections. It is important to note that even though the September
2008 Biological Opinion focused on salmon and EFH, all threatened or endangered species in
the project area need to be addressed in the assessment.
Existing documents can be referenced, where appropriate. Sources of existing species status
information include current NMFS Status Reviews, EFH information, current NMFS and
USFWS recovery plans, and Washington State Department of Fish and Wildlife management
recommendations (see the References section for links to these information sources). Another
source is the locally developed best available science documentation reports, which are required
to be prepared by each Puget Sound community for their critical areas standards under the
Growth Management Act.
The Corps of Engineers' ESA Consultation Initiation Template and NMFS' Consultation
Initiation Template and User's Guide provide similar guidance. This section's narrative could
follow the format and guidance provided in Section III.B Description of Species in these
Templates. Both the Corps and NMFS use the following outline:
i. Biological requirements
11. Factors of decline
a. Historical pressures on the species
b. Current pressures on the species
c. Limiting factors for recovery of the species
Habitat Assessment and Mitigation - 9 - January 1, 2010 DRAFT
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111. Local empirical information (if available)
a. Current local population information Exam le Prima Constituent Elements p rY
b. Ongoing monitoring programs (if any) Chinook salmon and steelhead trout 50 CFR Part ~ ,
C. Population trend of the species 226, Federal Register l Vol. 70, No. 170 l Friday,
September 2, 2005)
Following the description of the protected 1. Freshwater spawning sites with water quantity and quality conditions and substrate supporting
species, there should be a summary of the habitat spawning, incubation and larval development.
needs for each species. This section of the 2. Freshwater rearing sites with water quantity and
narrative needs to identify and describe the key floodplain connectivity
factors that are important for the protected 3. Freshwater migration corridors free of
species. These should include the primary obstruction
constituent elements identified in the final rules 4. Estuarine areas free of obstruction
that list threatened and endangered species. 5. Nearshore marine areas free of obstruction
Primary constituent elements are the key habitat 6.Offshore marine areas with water quality
components required for an ESA listed species, conditions and forage, including aquatic
as identified in the final critical habitat rules and invertebrates and fishes, supporting growth and
ublished in the Federal Re ister for listed maturation. p g
species (see example in the box).
2.3. Site Investigation
Tasks 2.1. and 2.2. give the applicant guidance on where to look and what to look for regarding
species potentially present at the site. Following completion of the first parts of Step 2, a site
visit is needed to determine if there are habitat areas with which identified species have a
"primary association". "Habitats of primary association" include critical components of the
habitats which, if altered, may reduce the likelihood that the listed species will maintain and
reproduce over the long term. A site visit and determination of site-specific conditions is
necessary to determine what actual impacts to ESA listed species, EFH, and associated habitats
may occur.
Habitats of primary association include, but are not limited to, winter ranges, migration ranges
and corridors, breeding sites, nesting sites, regular large concentrations, communal roosts,
roosting sites, staging areas, and foraging areas. This process must identify those areas discussed
in Step 2.2 as being primary constituent elements for each ESA listed species within the project
area. For example, identification of Chinook salmon habitat areas of primary association should
look for those constituent elements listed in the box above. This field work must include adjacent
lands and waters, upstream and downstream of the site.
The description of the project area habitat and conditions should also identify existing
modifications to the project site within the Regulatory Floodplain, including existing structures,
roads, impervious areas and graded or filled areas. Any existing modification that is impairing
habitats of primary association and habitat functions identified and described in the next section
should be described. Including activities to restore habitat in these modified areas could help the
assessment conclude that there will be no net loss of habitat due to the project (see also Task 3.3
of Step 3).
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The Washington Department of Fish and Wildlife's Management Recommendations for
Washington's Priority Habitats: Riparian (see References and Resources section of this
guidance) describes common land uses and modifications that impair riparian habitats. The
References section lists guidance materials related to other common floodplain and aquatic
habitat types.
2.4. Habitat Narrative
The findings of the field investigation are used to prepare a description of the habitat areas of
primary association that will need to be protected. The narrative for this part of the assessment
report needs to describe the presence and quality of the natural features that relate to the primary
constituent elements for all species and habitat areas identified in Tasks 2.2 and 2.3. As
described in the final paragraph of Task 2.2, primary constituent elements are the key habitat
components required for an ESA listed species, as identified in the final rules and published in
the Federal Register when species are listed.
It is possible that there maybe limited information available from the sources identified in Tasks
2.1 and 2.2. The habitat narrative should note where this occurs and clarify where statements are
based on scientific reports and data and where they are based on the professional opinion of the
author.
The habitat narrative includes an assessment of the components and processes for each of the
habitats of primary association identified during the site investigation. The narrative should
identify what components and processes have a high level of function and what components and
processes are impaired by previous site and/or area (i.e. watershed level, basin level)
modifications. The narrative should include the following headings for each identified habitat
area to ensure that the assessment will cover all items required by the Biological Opinion
(Appendix A, part 3) and Section 7.7.B of the Model Ordinance:
A. The primary constituent elements. These are identified in the final rules that designated
critical habitat for listed threatened and endangered species (see the NMFS and USFWS
critical habitat map links within the References and Resources section to access final
rules for ESA listed species). For example, for an inland site with Chinook salmon habitat
(see box, previous page), the first three sections of the habitat narrative would cover
freshwater spawning sites, freshwater rearing sites, and freshwater migration corridors.
B. Water quality. Discussion of existing water quality should identify water quality levels
within project area water bodies and compare existing levels to state standards. The
standards for freshwater surface water quality in Washington State are set by WAC 173-
201 aand are detailed by the Department of Ecology (www.ecy.wa.gov/
programs/wq/swgs/criteria.html). Information in Washington State's Water Quality
Assessment (303(4)) should be supplemented with any known site specific information
(information on 303(4) is found at www.ecy.wa.gov/Programs/wq/303d/index.html).
Local and county environmental managers or land use planners should be contacted to
assist in identifying relevant water quality information.
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C. Water quantity. Site flood dynamics and hydrology should be assessed. Flood and low
flow depths, volumes, velocities, and flow paths have an important effect on the way
habitat is formed. The habitat narrative should describe these factors with an emphasis
placed on the effects of flood events on habitats. Tributary streams, seeps, stormwater
outfalls, waterways that pass through the project site, and other water sources should be
identified and described. This discussion may rely on and reference other flood and site
hydrology studies prepared for the project and should be focused on how flood dynamics
and hydrology impact habitat areas. Generally a qualitative assessment of water quantity
should be sufficient, although projects where more significant impacts to water quantity
conditions may occur should include quantitative assessment of existing conditions.
D. Vegetation communities and habitat structures. This should include a discussion of
riparian vegetation and woody debris, along the banks and throughout the mapped
channel migration area. Freshwater riparian conditions should be characterized consistent
with the guidance in Management Recommendations for Washington's Priority Habitats:
Riparian. Characterization ofmarine shoreline conditions should be consistent with
guidance from the Washington State Departments of Fish and Wildlife and Ecology
(Land Use Planning for Salmon, Steelhead and Trout), and with other Puget Sound
nearshore guidance materials listed in the References and Resources section of this
gul ance.
E. Spawning substrate (only needed for ESA listed fish species)
F. Floodplain refugia (only needed for ESA listed fish species)
2.5. Habitat Area Map
Once all habitat areas of primary association are identified and described, they should be
delineated on a map. The map should be to the same scale as the proj ect area map (Task 1.2) to
facilitate comparison of the habitat to be protected with the extent of the Regulatory Floodplain,
the Protected Area, the riparian habitat zone, and other features.
Step 3. Describe the Project
There are two key parts of the proj ect that need to be described at this stage of the assessment
report: the final project, i.e., what the area will look like and how it will be used when the
proj ect is completed, and the construction process that will be followed to get there. The final
project should be covered first. Measures taken by the developer to prevent or minimize damage
to the habitat areas should also be included and highlighted.
As with Task 1.1, if a Washington State Joint Aquatic Resources Permit Application (DARPA)
form has been prepared for the project, it will include all project description information required
for the habitat assessment. The DARPA form template can be found at:
www.nws.usace.army.mil/PublicMenu/Menu.cfm?sitename=REG&pagename=Home_Page
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If the information is already being provided in a Washington State DARPA, the community may
accept the application form as sufficient for the project description.
If a Washington State DARPA has not been prepared for the project, the project area description
should include the information included in Tasks 3.1 and 3.2 of this section.
3.1. Final Project
All features present when construction is finished should be described. This includes:
- A summary of the project, including all features that will be present when construction is
finished
- Project category (industrial, commercial, residential, institutional, transportation,
recreational, maintenance, environmental enhancement)
- All structures, including boat launches, fences, docks, and pilings, etc.
- Roads, bridges, culverts, trails, and pavements
- All structures or facilities that would impact water bodies or wetlands, including
aquaculture, buoys, mining, bank stabilization, channel modifications, culverts, dams,
levees, ditches, fishways, moorage, outfall structures, etc.
- Above and underground utilities
- Water supply
- Wastewater disposal
- Stormwater management facilities
- Non-native landscaping
The level of detail for these descriptions maybe generalized for those features located outside
the identified habitat areas. The features need to be shown on one or more maps that will
facilitate relating the proj ect to the project area map (Task 1.2) and the habitat area map (Task
2.5).
There should also be a description of:
- The ongoing activities that will be conducted at the site
- Ongoing activities that will affect adjacent areas, such as an increase in traffic, an
increase in Stormwater runoff from the site, increased noise, and changes air quality.
3.2. Construction Process
At a minimum, this section should cover the following points:
- Land clearance (areas to be cleared and native vegetation that will be removed)
- Any work in water, including a description of the methods and materials used
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- Grading and filling
- Stormwater management measures taken during construction
- Utility installation (including any on-site wastewater treatment)
- Methods and techniques for construction of structures, including buildings, roads,
bridges, paved areas, retaining walls, shoreline modifications, and types of equipment.
- Construction phasing and anticipated construction timing.
- Mobilization and staging plans.
- Temporary construction access and staging areas.
Maps and a timeline are needed to show where and when each activity will occur.
3.3. Protection Measures
There are several Federal, State, and local regulatory requirements for developments to include
measures that minimize their impact on the environment. Others may be initiated by the permit
applicant. These should be described here. They could include:
- Preserving a setback area from any disturbances
- Drainage/erosion control plan during construction
- Post-construction Stormwater/drainage plan
- Use of low impact development techniques (which may eliminate or reduce runoff from
areas to be developed)
- Wetland mitigation plans
- Compensatory storage provisions to replace lost floodplain storages
Those protection measures that benefit the construction process, such as a sedimentation basin,
should be included in the construction process timeline.
Step 4. Assess the Impact
The impact assessment must analyze the direct and indirect effects of the action on the aquatic,
riparian, and floodplain habitat areas identified in Step 2, as well as effects of future actions
reasonably certain to occur. Primary factors to be considered in the assessment of impacts
inc u e
s Compensatory floodplain storage requirements are included in Section 7.6 of the Model Ordinance. Model
Ordinance requires that compensatory storage areas must be graded and vegetated to allow fish passage during flood
events without creating fish stranding sites. Areas of compensatory flood storage should be designed to create
floodplain habitat whenever feasible.
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- Proximity of the action to identified habitat areas
- Distribution, timing, and nature of the effect
- Duration
- Disturbance frequency, intensity, and severity
4.1. Types of Impacts
The References section at the end of this document lists resources that have additional guidance
for the assessment of impacts.
Direct effects: According to ESA rules and regulations, direct effects occur at or very close to
the time of the action itself. Examples could include construction noise disturbance, loss of
habitat, or sedimentation that results from the construction activity. The discussion should
include information on the temporal and spatial limits of the effects, species tolerances, severity
of effect, mortality and other forms of take, and expected habitat loss as a result of the proposed
action.
Direct impacts a project may have on a habitat area include, but are not limited to:
- Permanent clearing and grading of any habitat area;
- Temporary clearing and grading of any habitat area during construction;
- Permanent structures, pavements, etc., constructed within or placed within a habitat area;
- Modification of a stream channel or side channel including bank stabilization measures
and removal or changes to large woody debris (other than stream restoration efforts); and
- Diversion of water that will change the hydrology of the area
Indirect effects: Indirect effects are also caused by or result from the proposed action, however
they are likely to occur later in time. They may occur outside of the area directly affected by the
action. Indirect impacts include, but are not limited to:
- Disrupting high or low stream flows, including impacts from stormwater runoff;
- Contributing to sedimentation that fills in substrate;
- Blocking a corridor that connects habitat areas;
- Increases in water body temperature and other water quality parameters through removal
of riparian vegetation;
- Disturbance of riparian vegetation (for example, clearing vegetation to the edge of a
forested riparian area);
- Moving or removing large woody debris;
- Destabilizing banks and modifying channel migration processes; and
- Modifying wetland areas through disturbance of adj acent vegetation or modification of
hydrology.
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Interdependent and interrelated actions: Determining whether other activities are interrelated
to, or interdependent with, the proposed project should be determined by asking the question:
Would the other activities occur in the absence of the proposed project (i. e., do they depend on
the project for their justification or have no independent utility without the project) ? If the
answer to these questions is "no," then the activities are interrelated or interdependent and should
be analyzed with the effects of the action.
Cumulative effects: Under the ESA, cumulative effects include the future effects of State, tribal,
local, or private actions that are reasonably certain to occur in the action area. Permit officials are
required to review the cumulative effects of a proj ect. If one proj ect has a minimal impact and
looks like it should be approved, there must still be a review of the impact of allowing all
similarly situated properties to construct similar projects. The result of everyone doing what
appears to be a minor proj ect could have a maj or impact on aquatic and riparian habitat. The
permit applicant should keep this in mind during this assessment.
4.2. Report Format
The outline below is a variation on the NMFS and Corps guidance in Section V. Effects of the
Action in their Consultation Initiation Templates.
A. Direct effects
1. First primary constituent element (e.g., freshwater spawning sites2);
2. Second primary constituent element (e.g., freshwater rearing sites);
3. Third primary constituent element (e.g., freshwater migration corridors);
4. Essential Fish Habitat designated by the National Marine Fisheries Service;
5. Fish and Wildlife Habitat Conservation Areas;
6. Vegetation communities and habitat structures;
Water quality;
8. Water quantity, including flood and low flow depths, volumes and velocities;
9. The channel's natural meandering pattern;
10. Spawning substrate, if applicable; and/or
11. Floodplain refugia, if applicable
B. Indirect effects (see the list on the previous page and include consideration of indirect
effects to items A.l through A.l 1, above, that are applicable to the proposed project.
C. Effects from interdependent and interrelated actions
D. Effects from ongoing project activities (e.g. operations and maintenance)
E. Effects determination
F. Summary
2 Primary constituent elements are key habitat components for ESA listed species as specified in the Federal
Register at the time of critical habitat designation for listed species. See the discussion on page 10 of this guidance
for further information.
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4.3. Effects Determination
An effect determination needs to be made for each identified habitat area. Determinations for
each area can then be used to make an overall project effect determination. For example, if there
are no effects to all the identified habitat areas, then the overall determination would be that the
proj ect would have no effect. However, if some habitat areas are affected, then the proj ect would
be determined to potentially have an affect. In such instances, effects determinations for each
identified habitat area would inform efforts to mitigate any adverse effects. It is important to
document how the effects determinations were reached.
NMFS, USFWS, and the Corps use the following effects determination criteria:
- No Effect (NE): the project has no effect whatsoever to the listed species or designated
critical habitat.
- May Affect, Not Likely to Adversely Affect (NLAA): the effects to the listed species or
designated critical habitat are insignificant and/or discountable. A determination of
NLAA would be made for those activities that have only a beneficial effect with no short
or ong-term a verse impacts.
- Likely to Adversely Affect (LAA): the effects of the project will result in a short -or
long-term adverse impact on the identified species or designated habitat area.
If the effects determination is NLAA, the report should indicate what minimization and
conservation measures would help eliminate or minimize the impact. For example, the permit
applicant could time certain construction work to occur when the species are not present in the
project area. If such measures do not eliminate the potential adverse affect(s), then mitigation
measures will be needed in the mitigation plan (steps 5 - 6).
4.4. Assessment Report
If the assessment concludes No Effect (NE) or May Affect, Not Likely to Adversely Affect
(NLAA) (with minimization and conservation measures), then the report should be prepared and
submitted to the community's permit office. For NLAA determinations that include
minimization and conservation measures, the assessment must include enough detail to show
how the measures are related to potential proj ect impacts.
The assessment report should include all the information needed to support the effects
determination and the rationale for reaching the conclusion(s). It could be organized to follow
Steps 1- 4 as outlined in this document. The level of detail should be commensurate with the
level of anticipated impacts. Projects with significant impacts or potential for significant impacts
(due to proj ect type and/or proj ect location) require more detailed review and analysis.
If the assessment concludes Likely to Adversely Affect (LAA) or NLAA and there are no
minimization or conservation measures included in the project design, then the assessment will
need to proceed to Step 5.
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Preparing the Mitigation Plan
The following sections (Steps 5 and 6) provides guidance on preparing a mitigation plan,
including reference to other habitat-specific restoration and mitigation guidance materials
developed for the Puget Sound region. The final objective of floodplain habitat mitigation should
be to ensure that there is no net loss of habitat, in terms of features, area, and/or function. Step 6,
Task 6.1 of this guidance provides additional guidance on mitigation objectives, including
specific requirements for mitigation within Protected Areas and the Regulatory Floodplain.
For many development proposals, permit conditions and mitigation actions required to meet
other local and state permit requirements may also provide mitigation for the impacts determined
through Step 4 of this guidance. In such instances, permit conditions and mitigation actions may
overlap to serve as mitigation for impacts to floodplain habitats as required by the local flood-
plain management ordinance. The conditions and mitigation proposed, however, must be
sufficient to mitigate for all floodplain habitat impacts in order to meet the objective of no net
loss of habitat.
Step 5. Review Mitigation Alternatives (Mitigation Sequencing)
5.1. Avoidance
There are four major types of alternative mitigation approaches to rectify an adverse impact.
They are listed in order of preference and effectiveness: avoidance, minimization, restoration, and compensation. They may work independently or in combination. The final obj ective
is to
provide sufficient and appropriate mitigation to compensate for habitat impacts, in terms of
features, area, and/or function.
Avoidance is the preferred approach. It is recommended that a development project stay out
of the Regulatory Floodplain rather than implement activities needed to mitigate the project's
adverse impact on aquatic and riparian habitat. Therefore, at this stage, the permit applicant
should give serious consideration to relocating or redesigning the proposed project to avoid
floodplain habitat impacts and the need for a mitigation plan.
The community may want to encourage a development to avoid the Regulatory Floodplain with
additional incentives. Puget Sound communities currently use many strategies to encourage
conservation of certain areas by allowing for development at a more intense level in other areas.
These are usually provisions of a zoning ordinance or separate development regulations. There
are three approaches, amongst others, that Puget Sound jurisdictions use to encourage
conservation:
1. Providing density incentives to individual property owners: A density incentive or
density credit system would allow specified land uses to occur at a more intense level
within a portion of a parcel outside of the floodplain as compensation for conservation of
floodprone areas within the parcel. For example, if a 20 acre parcel is zoned for one acre
lots and half of the parcel is in the Regulatory Floodplain, the community might consider
allowing the 10 "dry" acres to be developed with half acre lots, allowing the development
Habitat Assessment and Mitigation -18 - January 1, 2010 DRAFT
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to still construct 20 homes. This would allow for a higher density of development in a
portion of the property and would require the remaining, high habitat value floodplain to
be conserved as a dedicated tract. This strategy is similar to clustering development
methods, such as is often used in planned unit developments. Under both approaches, the
overall project does not exceed the development density allowed by the zoning district.
2. Transferable development rights: Transferable development rights (TDR) systems have
been in limited use by certain jurisdictions within the Puget Sound region in recent years.
TDR systems allow for the transfer of development density from one parcel of land (with
some conservation value, such as a floodplain or wetland) to another parcel or area that is
planned for higher density development. Implementation and administration of TDR
systems has proven challenging in many circumstances, due to the required coordination
in establishing density receiving and density giving areas, and in negotiating density
credit values. However, a community, regional, or watershed based TDR system maybe
a successful strategy for floodplain avoidance.
3. Tax relief for conservation lands: Tax relief is a financial incentive that has proven to
discourage development of sensitive lands. King County has an established system of
providing property tax relief for lands that are established as conservation areas. All
projects must meet certain criteria and approval is not automatic. Such a system could
provide an additional venue to encourage conservation of floodplain lands.
5.2. Minimization
If the entire proj ect cannot avoid the Regulatory Floodplain, it may be that it can be designed to
minimize the areas of impact by keeping more disruptive parts of the project out of identified
high value habitat areas. For example, while water access maybe necessary for the project, the
design might place all buildings and pavements out of the riparian habitat zone. Here are some
ideas for this approach:
- Site the project footprint away from the higher value habitat areas.
- Designate buffer areas that are not disturbed during or after construction (note that
Section 7.4 of the Model Ordinance prohibits disturbing native vegetation in the riparian
habitat zone without mitigation).
- Include vegetation enhancement plans around the site's active use areas.
Many adverse impacts are due to the disruption caused by construction. Here are some ideas to
avoid these types of problems
- Perform all work in dry weather and/or during the dry season
- Incorporate erosion and sedimentation control measures
- Use vegetable oil-based hydraulic fluids in all equipment working in water
- Prepare and train crews on a spill prevention and pollution control plan
- Store, stage, and refuel equipment outside the riparian habitat zone
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- Inspect equipment daily foi• leaks
- Time specitic phases of wark to occur during "species work windows." when the species
arc not present or will not be al~fected
5.3. Restoration
tr G I► . •.r ~
. r ' r t 'pt aiy' ~ .1
•
A ~1'OjCCl'S plaIIS S~IOUiCj 11lClUC~C I'eStOi'!]1~.~ ~ ~ ~ ~ `~~'k~_ • .
or improving areas disrupted b}' the
construction process. Wetlands, channels,
~ fiAr
and riparian areas can be rcpaired or
Mi ~
rebuilt a1ter the land clcaiance, grading
OL
and filling is done. ,^11 areas temporarily bi ~.-.r , - ~ , : •
clearcd should be re-~~e~~etated ~~~ith native T' ; • ~ ~
+
~c~.IZLS.
p
In some cases, restaration projects can be
improvcments to conditions that existed
bef0[e thl; pl'OjCCY. Atl f'!iai7lple Of thlS, ~,Vh~ii tfie Tarboo Creek lrridye was replaced in 2004,
Jefferson County used the opportunity to restore the
where a 1c:fferson County stream ~~~as stream to be more like it was before earlier bridges were
enhanccii during a bridge repl~iCet71et1t built. A iong, narrow culvert was replaced with a deeper
prOjeCl, 15 deSCt'ihed it1 tlle box to the channel, a wider opening, and woody debris. The former
bridge and high stream velocities impeded travel of some
t'lght. species of fish, including salmonids. The new
arrangement improves fish passage and carries higher
5.4. Compensation flood flows without overtoppinp the road.
Restoration measLu•es can mitigate thc impact of temporary disruption, as xvhen an area is torn up
for coilstrtictioil hut intended to retnain as open spacc. Restoration can produce an equal or better
habitat at the same ]ocation.
Permanent changes to the land and ~vatcr that cannot be avoidzd ,vill need to be compensated for.
Compensation should always produce an equal or better habitat, even though it will he in a
differenl location (which tnay or may not be on the owner"s property). It should be noted that the
compensation ineasure must accotint ior tlic liabitat Ilinctions and c:lcincnts identilied il1 Step 2.
Some tunctions, such as a freshNvatrr mioration corridor. will not w•ork in a different location.
The aliplicant should also keep in mind that the area rCyuired for cotnpensation is ;generally
greater than the area of impact. f3ecause ol'the leng,th ol'time ii takes to successfiilly crcate a
stream side channel. wctland, or upland 1loodplain hahitat ai•ea, greater acreage should be
provided to compensate for the lost habitat area. (See thr Auburn Narrows eompensation
cxamplc. nr-xt pa~~e.)
Hafiitat ~1sscs;ment ancl Miti~~ation -'0 - .lanuar~~ I. ~0 10 DRAFT
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5.5. Select the Best Approach(es)
Selecting the best mitigation approaches for the proposed project is an iterative process. It should
consider avoidance as the preferred choice. If work must be done in a sensitive area, it should
consider the costs of restoration and compensation. If those costs aze too high, avoidance should
be reconsidered.
Selecting the best mitigation approach can and should be done in conjunction with the local,
State, and Federal regulatory offices. Involvement of their knowledgeable staff allows discussion
of the approaches and evaluation of preliminary project designs. This can save a lot of work
designing the mitigation project. Early and periodic meetings with appropriate regulatory
agencies can increase the likelihood of the mitigation plan meeting all regulatory requirements
and can reduce potential costs and schedule delays during the approval process.
t
N
Auburn Narrows floodplain restoration projecl along the Green River, King County. This project was
funded by a developer of a nearby site in order to compensate for the adverse impact of a floodplain
development. The project included creation of side-channel habitat, off-channel habitat, and riparian
habitat.
- ESA Adolfson
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Step 6. Prepare the Mitigation Plan
6.1.Objective
As noted in Step 5, the objective of the mitigation plan is to assure that sufficient and appropriate
mitigation is provided to compensate for habitat impacts, in terms of features, acreage, or
function. If the assessment cannot conclude that the proj ect will have No Effect (NE) or May
Affect, Not Likely to Adversely Affect (NLAA), then the mitigation plan needs to identify
activities that will result in NE or NLAA. The plan document needs to be of sufficient detail to demonstrate how this is done, using avoidance, minimization, restoration, and/or compensation
measures.
Obj ectives for mitigation are differentiated for those impacts occurring within Protected Areas
and those impacts occurring within the remainder of the Regulatory Floodplain. Mitigation
within the Protected Area must include such avoidance, restoration, and/or compensation
measures as needed to ensure that there is no net loss of habitat function due to the project.
Minimization measures are not allowed in the Protected Area, unless they, in combination with
other measures, result in no net loss of habitat function (Model Ordinance Section 7.8.A.2).
The following are strategies by which the mitigation objective for Protected Areas maybe
ac ieve
- Doubling or tripling the area of compensatory mitigation to increase the mitigation ratio
(area of habitat impacts : area of compensatory mitigation provided).
- Identifying additional areas of previously degraded habitat within the project area and
developing and implementing a plan to restore them.
- Implementing restoration actions which are targeted as a high priority by an adopted and
approved species recovery plan, when such actions are identified within the site and/or
within the same basin or reach area, and approved by local, state, and federal permitting
agencies.
For all mitigation, the final plan (construction level detail) should not be drafted until the local
permitting office(s), incoordination with state and federal agencies, as necessary, has agreed that
the conceptual mitigation plan would meet the objective. Coordination with local permitting
officers will ensure that the scope of the planned mitigation will be commensurate with the scale
of the impacts and will meet the objectives identified above.
6.2. Format
Many communities have tried and true formats for environmental assessments. It may be easier
for all involved to keep to that format. Otherwise, Chapter 2 of Wetland Mitigation in
Washington State Part 2: Developing Mitigation Plans has detailed guidelines on what to
include in a mitigation plan. There is a recommended outline in Appendix C of that publication
which is geared to larger projects involving complex habitat impacts and mitigation. Smaller less
complex projects involving small impacts may not require all the information in the outline
because it may not be relevant or applicable.
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Here is an example mitigation plan outline;
1. Introduction, background, etc.
2. The project area, with map (taken from Step 1 of the assessment)
3. The project area's habitat, with map (taken from Step 2 of the assessment)
4. Project description (taken from Step 3 of the assessment)
5. Impact on habitat (taken from Step 4 of the assessment)
6. Alternatives considered (taken from Step 5, this should note why some alternatives,
especially avoidance, were not selected)
Mitigation concept (an overall explanation of the measures)
8. Construction measures
a. Grading plan, with existing and post-construction topographical maps
b. Construction methods (e.g. equipment to be used)
c. Construction schedule
9. Permanent measures
a. Surface water management
b. Vegetation plan
c. Permanent buffer areas
d. Etc.
10. Post-construction monitoring and maintenance plan
1 1. Bond arrangements
6.3. Minimum Standards
At a minimum, the mitigation plan's components 8, 9,10, and 11 should be consistent with the
mitigation guidance requirements of the Seattle District of the Corps of Engineers and Wetland
1Vlitigation in Washington State Part 2: Developing 1Vlitigation Plans (see Reference section)
and with the community's critical areas regulations. If there are inconsistencies between these
requirements, the standards that provide the highest level of environmental protection and the
greatest likelihood of mitigation success take precedence.
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Reviewing Habitat Assessments and Mitigation Plans
This section provides guidance for the local permit official. The following strategies may be used
to ensure that habitat assessments and mitigation plans are prepared by a qualified individual or
company and meet the intent of the Model Ordinance and this guidance.
Establishing a List of Qualified Consul-
tants: The community could provide a list Example Qualification Criteria
of qualified consultants to developers and The following qualification criteria could be used by a land owners who have experience in the community to ensure that habitat assessments
and
mitigation plans are prepared by a qualified consultant: area. Another strategy for ensuring that
Reports and plans shall be prepared by persons who qualified consultants are used could include have a minimum of a bachelor's degree in wildlife or
developing qualification criteria for authors fisheries habitat biology, or a related degree in a
of habitat assessments and mitigation plans; biological field from an accredited college or university
see the box to the ri ht for an exam le of with a minimum of four years experience as a
g p practicing fish or wildlife habitat biologist. one community's criteria. When used, qualifying criteria should include specifica-
tionsfor all wildlife, fisheries, habitat, and environmental
Public Comment Period: After habitat professionals that could be relied upon to address the
broad array of habitats and conditions that occur in assessments and mitigation plans are floodprone areas.
submitted, the permitting official may
require a public comment period before
assessment conclusions and/or mitigation plans are approved. This approach could include a
requirement that public notice be posted in a publication of record. The intent of the public
comment period would be to ensure that interested third parties would have ample opportunity to
review and comment on proposed projects. This could alert the local permit official to issues or
impacts not adequately addressed by an assessment or mitigation plan.
Third Party Review: The community may establish a system of third party review(s) by
qualified consultants or agencies. Third party review is frequently implemented by local
jurisdictions in the Puget Sound region for other environmental permits and approvals. The cost
of third party review could be passed on to the applicant. This may require establishment of a
third party review system in the ordinance.
Establishing a system of third party review could augment internal review within the local
jurisdiction. Another option for certain jurisdictions could be formalizing a system of internal
review where qualified staff would determine the adequacy of submittal materials.
Review Checklists: Permit staff could develop a review checklist for assessment and mitigation
plan submittals. A checklist would likely need to be tailored to specific types of development
activity due to the site- and habitat-specific nature of habitat assessments and mitigation plans.
Habitat Assessment and Mitigation - 24 - January 1, 2010 DRAFT
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References and Resources
Federal and State Regulations
"Endangered Species Act -Section 7 Consultation, Final Biological Opinion," National Marine
Fisheries Service, September 22, 2008
NFIP-ESA Model Ordinance, FEMA 2010. www.
NFIP Floodplain Management Requirements A Study Guide ~ Desk Reference for Local
Officials, FEMA 480, 2005, www.fema.gov/library/viewRecord.do?id=1443
1Vlitigation guidance and JARPA Permit information, Army Corps of Engineers, Seattle District.
http a/www.nws.usace. army.mil/PublicMenu/Menu. cfm?sitename=REG&pagename=Forms
Regional Guidance on Floodplain Habitat Assessment and Mitigation, FEMA Region X, 2010,
www.fema.gov/about/regions/regionx/NFIP_ESA/habitatassessmentandmitigation.pdf
Maps and Databases
Critical habitat maps:
- NMFS: http://www.nmfs.noaa.gov/pr/species/criticalhabitat.htm
- US Fish and Wildlife Service: http://criticalhabitat.fws.gov/
Forest Water Typing System: Washington Department of Natural Resources
www.dnr.wa.gov/BusinessPermits/Topics/ForestPracticesApplications/Pages/fp_watertyping.aspx
A Framework for Delineating Channel 1Vligration Zones. Washington State Department of
Ecology and Washington State Department of Transportation, Ecology Publication # 03-06-027,
2003. httpa/www.ecy.wa.gov/biblio/0306027.html
National Wetland Inventory maps for the Puget Sound Region, U.S. Fish and Wildlife Service,
http ://www. fws. gov/wetlands/
Priority Habitats and Species (PHS) Database, Washington Department of Fish and Wildlife, http://wdfw.wa.gov/hab/phslist.htm
Washington Natural Heritage Database, Washington Department of Natural Resources,
http://www.dnr.wa.gov/ResearchScience/Topics/NaturalHeritage/Pages/amp_nh.aspx
Washington State Soil Survey data, see the USDA Natural Resource Conservation Service maps
or online Web Soil Survey, http://websoilsurvey.nres.usda.gov/app/
Habitat Assessment and Mitigation - 25 - January 1, 2010 DRAFT
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Water Quality and Quantity
How to 1Vleet Ecology's Construction Stormwater General Permit Requirements: A Guide for
Construction Sites, Washington State Department of Ecology, 2008,
httpa/www.ecy.wa.gov/biblio/9937.html
Standards for freshwater surface water quality in Washington State, Department of Ecology
http://www.ecy.wa.gov/programs/wq/swgs/criteria.html
Stormwater 1Vlanagement Manual for Western Washington, Washington State Department of
Ecology, 2005, http://www.ecy.wa.gov/programs/wq/stormwater/manual.html
Washington State Water Quality Assessment, Washington State Department of Ecology,
http://www.ecy.wa. gov/programs/wq/3 03 d/2008/index.html
Water level data:
- US Geological Survey: http://wa.water.usgs.gov/data/
- Washington Department of Ecology:
http://www.ecy.wa.gov/programsleap/flow/shu_main.html
Mitigation
Engineering with Nature -Alternative Techniques to Riprap Bank Stabilization, FEMA Region
X, 2009
Floodplain and riparian corridors: Washington Department of Fish and Wildlife (Bolton and
Shelberg, 2001) http://wdfw.wa.gov/hab/ahg/floodrip.htm)
Habitat Conservation Planning Handbook, US Fish & Wildlife Service and National Marine Fisheries Service, 1996, http://www.fws.gov/endangered/hcp/hcpbook.html
Land Use Planning for Salmon, Steelhead, and Trout: A Land Use Planners Guide to Salmonid
Protection and Recovery, Washington State Department of Fish and Wildlife and Washington
State Department of Ecology, 2009, http://wdfw.wa.gov/habitat/plannersguide/index.html
1Vlanagement Recommendations for Washington's Priority Habitats: Riparian, Washington
Department of Fish and Wildlife, 1997; http://wdfw.wa.gov/hab/ripxsum.htm
Protection and Restoration of the Nearshore Ecosystems of the Puget Sound, Puget Sound
Nearshore Partnership, 2004, httpa/www.pugetsoundnearshore.org/technical_reports.htm
Stream Habitat Restoration Guidelines, Washington Department of Fish and Wildlife, 2004,
http://wdfw.wa.gov/hab/ahg/shrg/index.htm
Habitat Assessment and Mitigation - 26 - January 1, 2010 DRAFT
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Wetland 1Vlitigation in Washington State Part 2: Developing Mitigation Plans, Washington
Department of Ecology, US Army Corps of Engineers, and US Environmental Protection
Agency, 2006, http://www.ecy.wa.gov/biblio/060601 lb.html
Additional References
Invasive species information: Washington State Noxious Weed Control Board.
http a/www.nwcb.wa.gov/weed list/weed_list.htm
Low Impact Development, Puget Sound Partnership. Available:
www.psp.wa. gov/stormwater.php
Habitat Assessment and Mitigation - 27 - January 1, 2010 DRAFT
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Regional Guidance for NFIP-ESA
Hydrologic and Hydraulic Studies
Contents
Introduction l
Background l
Hydrologic and Hydraulic Study Guidance l
Future Conditions Floodplain Studies 3
Background 3
Types of Future Conditions 4
When to Analyze Future Conditions 6
Future Conditions Hydrologic Analysis 7
Future Conditions Hydraulic Analysis 7
Future Conditions Summary 8
CRS Credit for Future Conditions Mapping 8
Hydraulic Models ..................................................................................................10
Current Models .................................................................................................10
Regional Guidance ............................................................................................11
CRS Credit for Hydraulic Modeling .................................................................12
Channel Migration Zones .....................................................................................13
Background .......................................................................................................13
Biological Opinion Requirements ....................................................................13
Regional Guidance ............................................................................................14
CRS Credit for Mapping Channel Migration Zones .........................................16
Appendix A. References l
Appendix B. Flow Control-Exempt Surface Waters l
NFIP-ESA H&H Guidance - i - January 1, 2010 DRAFT
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Acknowledgements
This guidance document was developed by Region X of the Federal Emergency
Management Agency, as part of its continuing effort to improve floodplain
management practices and assist communities in meeting the requirements of the
Endangered Species Act.
It was prepared with the advice and assistance of a special advisory committee
that included representatives from:
- City of Auburn
- City of Carnation
- City of Everett
- Jefferson County
- King County
- City of Lacey
- Lummi Nation
- City of Monroe
- Pierce County
- Snohomish County
- City of Tukwila
- Washington State Department of Ecology
- Whatcom County
While some comments were not incorporated, the reviews of each agency in a
common endeavor to make this a useful guidance tool are appreciated.
This document was drafted by French & Associates, Ltd., Steilacoom, ESA
Adolfson, Seattle, and PBS&J, Seattle, through an arrangement with the Insurance
Services Office and the Community Rating System.
NFIP-ESA H&H Guidance - ii - January 1, 2010 DRAFT
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Introduction
Background
This Regional Guidance is written for communities in the Puget Sound Basin to assist them in
meeting the requirements and criteria of the Endangered Species Act (ESA) as clarified in the
Biological Opinion issued by the National Marine Fisheries Service on September 22, 2008. The
primary audience for this guidance is engineers and other technical staff involved with mapping
flood hazards.
This guidance was prepared with input from local officials, engineers, natural resources
scientists, and planners. It will assist local officials and developers determine the most
appropriate ways to prepare flood hazard data that meet the requirements of the National Flood
Insurance Program (NFIP) and the ESA.
This document is designed to support the NFIP-ESA Model Ordinance, which was also prepared
by FEMA Region X.
Hydrologic and Hydraulic Study Guidance
FEMA develops flood data and publishes flood hazard maps to support the NFIP. The data are
summarized in Flood Insurance Studies and the maps are known as Flood Insurance Rate Maps
(FIRMS). These products define the Special Flood Hazard Area (SERA), which is the area
predicted to be inundated by a flood having a 1-percent probability of being equaled or exceeded
in any given year (also referred to as the 100-year flood or base flood). The SFHA designates the
minimum area that a community in the NFIP must regulate. The "Regulatory Floodplain," as
defined in the model ordinance, is the SFHA plus those areas of riparian habitat and channel
migration areas that extend beyond the SFHA.
There are normally three major phases to a FEMA flood study of a stream or river:
1. Assess the flows (usually involving a hydrologic study)
2. Determine flood elevations and the floodway (via a hydraulic analysis)
3. Map the floodplain (SFHA) and floodway
Flood studies conducted for the NFIP are prepared by mapping partners, including state and
regional agencies and local governments. FEMA's mapping criteria are spelled out in Guidelines
and Specifications for Flood Hazard Mapping Partners (called Guidelines and Specifications in
this document), which are available at http://www.fema.gov/plan/prevent/fhm/gs_main.shtm.
Guidelines and Specifications includes technical appendices which are updated as necessary. The
primary technical appendix that relates to the issues discussed in this Regional Guidance is
Appendix C: Guidance for Riverine Flooding Analyses and Mapping (FEMA, 2002).
NFIP-ESA H&H Guidance -1- January 1, 2010 DRAFT
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This Regional Guidance is intended to supplement existing guidance for communities who wish
to prepare studies in consideration of special ESA provisions for Washington State as explained
in the Biological Opinion. The Biological Opinion identified three specific areas where study
techniques need to be adjusted to provide better hazard data:
- Use foreseeable future land use changes to establish future base flood elevations,
- Use unsteady one-dimensional ortwo-dimensional hydraulic models to analyze complex
riverine systems when applicable, and
- Include the channel migration area as part of the regulatory floodplain.
These three subjects are covered in the following three sections. Communities are not required to
use this guidance and it does not define the only approaches to follow. However, communities
that do follow this guidance will meet the ESA requirements as spelled out in the Biological
Opinion, and have a more effective program to reduce the dangers and damage caused by floods
and migrating stream channels.
Each section also includes a discussion of how each of the three maj or elements of
this guidance relate to potential Community Rating System (CRS) credits. More
information on the CRS can be found in Appendix D of the NFIP-ESA Model
Ordinance and at http://www.fema.gov/business/nfip/crs.shtm.
NFIP-ESA H&H Guidance - 2 - January 1, 2010 DRAFT
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Future Conditions Floodplain Studies
Background
Flood Insurance Rate Maps serve several purposes:
- They guide local floodplain management programs,
- They establish insurance premium rates, and
- They are used to determine when a flood insurance policy is required under the
mandatory purchase requirement.
After a review of the legal issues, FEMA's counsel concluded that FIRMS used for the last two
purposes need to be based on the current conditions on the ground. In 2001, FEMA issued a
report, Modernizing FE1l~lA's Flood Hazard Mapping Program: Recommendations for Using
Future-Conditions Hydrology for the National Flood Insurance Program. That report noted:
As discussed in Flood Insurance Study Guidelines and Specifications for Study Contractors" (FEMA
37, January 1995), flood hazard determinations should be based on conditions that are planned to
exist in the community within 12 months following completion of the draft Flood Insurance Study
(FIS) report. Examples of future conditions to be considered in the context of FEMA 37 are public
works projects in progress, including channel modifications, hydraulic control structures, storm-
drainage systems, and other flood protection projects. These are changes that will be completed in the
near future for which completion can be predicted with a reasonable degree of certainty and their
completion can be confirmed prior to the NFIP map becoming effective....
The current procedure for flood insurance rating is that structures shown within the existing
conditions 1-percent-annual-chance (100-year) floodplain are subject to a mandatory purchase
requirement. Due to statutory constraints at this time, FEMA can not use future-conditions data for
flood insurance purposes. Therefore, there will be no change in the use of existing conditions data for
establishing flood insurance rates. Through community participation in the CRS, reduced flood
insurance rates are available for those communities that enforce more stringent regulatory standards than required by the NFIP. [pages 2 - 3, 5]
While the SFHA on a FIRM cannot be based on future conditions, local floodplain management
programs are welcome to use future conditions maps, as long as the regulatory floodplain is at
least as large as the currently effective SFHA. In fact, Recommendations for Using Future-
Conditions Hydrology concludes with a recommendation that FIRMS display the future
conditions floodplain for informational purposes. This has been done where requested by the
community.
The 2008 Biological Opinion stated:
The FEMA will also revise map modeling methods to consider future conditions and the cumulative
effects from future land-use change, to the degree that such information is available (e.g. zoning,
urban growth plans, USGS Climate study information). Future conditions considered should include
changes in the watershed, its floodplain, and its hydrology; climate change, and other conditions that affect future flood risk. The FEMA shall ensure that jurisdictions use anticipated
future land use
changes when conducting hydrologic and hydraulic calculations to determine flood elevations. [page
158]
NFIP-ESA H&H Guidance - 3 - January 1, 2010 DRAFT
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This section shows how the Biological Opinion requirements can be met within FEMA's current
mapping guidance.
Types of Future Conditions
The term "future conditions" has a number of possible meanings in the context of mapping flood
hazards. From a flood study perspective, there are two general types of changes that can be
expected to occur in the future:
- Changes in the amount of rain and snow that feed floods (climate change), and
- Changes in the watersheds that absorb the rain and snowmelt (land-use changes).
Changes in precipitation: Changes in precipitation due to climate change are possible. Climate
varies at many timescales, from daily cycles to the glacial-interglacial patterns that occur over
many thousands of years. Changing dimate patterns can be difficult to discern because of •
significant year to year variation and the short observational record.
Flood studies are necessarily dependent on past
precipitation and flow records, which do not provide
information on flows generated under different climatic
~
conditions. Therefore, existing information is not clear as to 1 . ~
how to alter peak flow predictions to account for a changing Ke
climate (see for example Brekke et al., 2009, Elsner et al., -a
2009, Rosenberg et al., 2009). Further, the magnitude of Z5% s 25%
changes in peak flows due to changing climatic conditions
is expected to be much smaller than changes resulting from
alterations to land use, described below. Therefore, no
specific consideration of changes in peak flow due ro ;1, cl imate change is included in this guidance. z21%
FEMA is cunently developing a report that will assess how 135:50%BovaG Surlncei
a changing climate will affect the NFIP. 7'he report will
include estimates of how climate change could impact ~ , - !
inland floodplains and coastlands. The report's findings will zo% : i5%
be incorporated into future versions of this guidance.
, These graphics show the relative
increase in runoff from a watershed
Changes in the watershed: Changes in land use and land as it is urbanized and the amount of
cover (e.g., conversion of forest or agricultural land to urban impervious surfaces increase.
land uses) can have significant impacts on the volume of - NAi rootkit, nSFPnn, zoo3
surface water runoff resulting from a given precipitation
event. Changes in land cover typically increase peak flows
by greater than 50 percent in small Puget Sound watersheds, and change the timing of peak flows
(see the graphic, Booth et al., 2002, Grant et al., 2008).
NFIP-ESA H&H Guidance - 4- January 1, 2010 DRAFT
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Forest harvest patterns in managed forest land can also influence runoff patterns. Harvest
patterns include re-growth, so it is assumed that future change from these processes is limited,
since the bulk of these impacts are already accounted for in past flow measurements.
Land-use and land-cover changes in the watershed are anticipated to have the most significant
impacts on peak flows. Therefore, the technical aspects of this guidance are focused on
anticipating and planning for flows generated from a more developed landscape.
Other physical changes in the floodplain include infrastructure changes, such as bridge
replacement, or land use conversion. If such changes are happening or scheduled within 12
months of a flood insurance study being undertaken, FEMA already requires their inclusion in a
new flood study.
Development in the floodplain also has the potential to result in cumulative affects on flood
storage. For example, if the fringe is filled, the base flood elevation could rise by up to one foot.
To comply with the Biological Opinion, communities will need to prevent filling of the
floodplain or include mitigation measures such as compensatory storage so that man-made
changes in the floodplain do not affect future flows. In addition low impact development
techniques are required for any development allowed within the floodplain. Therefore,
development within the floodplain should not have an impact on downstream flood peaks.
On the other hand, there could be natural changes in the floodplain that are not necessarily
addressed in Guidelines and Specifications. Local critical area regulations encourage preserving
the natural and beneficial functions of the floodplain. As riparian plant communities develop,
they may provide greater roughness along the channel banks and overbank areas, increasing
flood elevations in those areas.
Restoration projects, including levee setback proj ects, have the potential to change flooding
patterns. If an analysis finds that they do affect base flood elevations or the floodway or SFHA
boundaries, a CLOMR from FEMA is required. As more projects are completed, they may have
a cumulative impact on flood elevations. However, due to their expense, the few restoration
projects that have been completed cover relatively short reaches. The distribution and effects of
such future projects are difficult to predict. This Regional Guidance does not provide a
mechanism to capture this type of future condition.
Conclusion: Development in the watershed has a predictable and measurable impact on the
flow regime. This guidance recommends that communities evaluate changes to the base flood
from expected future watershed development based on the development patterns laid out in their
local long range land use plans. At the request of the community, FEMA will reflect the results
of the community-initiated future conditions study on FIRMS when they are revised. The
flooding extent determined by future conditions analysis and mapping can be depicted as a
shaded X Zone on the FIRM, instead of the 500-year floodplain.
NFIP-ESA H&H Guidance - 5 - January 1, 2010 DRAFT
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When to Analyze Future Conditions
There are two situations where it is not necessary to analyze and map future conditions:
1. Larger rivers: In general terms, the larger the river system, the less potential impact there
will be from changing land cover (see for example Grant et al., 2008, Herrera, 2004).
These larger systems where future conditions analysis is not required are the "flow
control-exempt" water bodies listed in the Washington State Department of Ecology's
Stormwater 1Vlanagement Manual for Western Washington. The list of these waters is in
Appendix I-E of the Ecology manual and Appendix B of this Regional Guidance. The list
should be updated in future versions of the Ecology manual.
2. No change expected: Future conditions do not need to be investigated in areas where the
contributing basin has already been developed and these conditions are reflected in
existing floodplain mapping. For instance, if the contributing watershed is in, and is
expected to remain in agriculture or managed forest, these basins do not need to be
analyzed for future conditions.
It is most important to capture future conditions for smaller streams that are located in or near
areas that are likely to urbanize, such as in or near a city or its urban growth area. For smaller
watersheds that are currently undeveloped or only partially developed, it is important to
investigate potential changes in peak flows when more than four percent of the overall watershed
will become effective impervious surface (Booth et al., 2002). As a general rule, future
conditions hydrology should be determined for all cases where over ten percent of a stream's
contributing basin is converted from existing forest lands or has an increase in impervious
surface.
These criteria are summarized in Table 1.
Analyze future Situation conditions
hydrology?
Study is for a large, flow control-exempt, water body No
The watershed is developed up to the levels shown in the land No
use or comprehensive plan
The watershed is managed forest or agriculture with no potential No for conversion
> 4% of the watershed will become effective impervious surface, Yes
or a >10 % increase is likely if existing condition is >4%
All other situations Yes
Table 1. When to analyze for future conditions
NFIP-ESA H&H Guidance - 6 - January 1, 2010 DRAFT
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Future Conditions Hydrologic Analysis
To develop a dependable future conditions 1 percent annual chance flow, it is necessary to rely
on rainfall runoff simulations with altered land use conditions. Gauge analysis has the benefit of
using measured data, but the data only reflect past land use, not the future.
All of the currently accepted hydrology models for peak flow determination (available at
httpa/www.fema.gov/plan/prevent/fhm/en_hydro.shtm) can be used to estimate future conditions
by changing land cover/use parameters. Some models, such as HSPF and SWMM, will be more
amenable to this type of analysis than others. All runoff models should be calibrated to past flood
events before they are used for base flood determination.
Future land use conditions can be developed using comprehensive plans developed by
communities to comply with the Washington Growth Management Act. These plans specify the
type of land uses and, sometimes, percentage of lot coverage allowed during a foreseeable
planning horizon, such as 20 years.
It is recommended that a conservative assumption be used that all of the areas in the watershed
will be developed as planned. This information can be used in the hydrologic model's land use-
to-land cover relationships to describe abuild-out condition within the watershed.
Stormwater management regulations usually require stormwater management facilities that will
minimize the impact of development on runoff. The 2005 Ecology manual requires that post-
developmentflow quantities be managed using flow frequencies ranging from 50 percent of the
2-year recurrence interval flow to the 50-year recurrence interval flow.
The influence of stormwater management facilities on the 1 percent annual chance flood is
considered to be negligible for the following reasons:
- They are required to have overflows sufficient to pass the post-development 100-year
flow,
- They can fail due to extreme flood conditions or deficiencies in design, installation, or
maintenance,
- Basic retention and detention regulations don't address timing, so there's no assurance
that future flooding will not be increased by the facilities, and
- The basic analytical technique is to ignore all private facilities because of long-term
maintenance issues.
Future Conditions Hydraulic Analysis
No changes to the existing hydraulic analyses techniques are necessary to develop future
conditions floodplain mapping based on land use changes as described above. The same models
and approach used for existing conditions can continue to be used with different flows developed
in the hydrologic analysis, with the exception of anticipating development of vegetation.
NFIP-ESA H&H Guidance - 7 - January 1, 2010 DRAFT
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Future conditions discharges are input into the hydraulic model to determine the future-
conditions flood hazards. Certain hydraulic parameters may also need to be adjusted based on
expected land-use and land-cover changes, as determined by the community.
Vegetation: It is a good floodplain management practice to consider the continuing
establishment of riparian vegetation along channel banks and in the floodplain. This
development could have significant influence on the study's roughness coefficient. For example,
using values from Chow,1959, a central roughness coefficient (Manning's n) for cultivated land
with no crops is 0.030, and a central value for medium to dense brush in winter is 0.070 (in
Sturm, 2001). The influence of the roughness coefficient on velocity calculations is linear, so
doubling this value will certainly influence the hydraulic calculations, the resulting base flood
elevation, and the extent of flooding.
Future conditions hydraulic modeling should consider the potential for riparian and floodplain
vegetation to establish and continue to develop. Therefore, future conditions can assume a full
riparian forest community (e.g., >50 years old). Agricultural areas can be considered to remain in
production and do not require adjustments.
Not all areas will be allowed to develop to full riparian forest. If a community has an operations
and maintenance plan (or similar) that includes vegetation maintenance (e.g., to comply with
PL84-99), then future vegetation development needs to be as prescribed in the plan.
Future Conditions Summary
Communities should analyze the future conditions flood hazards by using the rainfall runoff
models and hydraulic models described in Guidelines and Specifications. Future conditions are
generally impacted by changes to the land cover conditions. These estimates should be predicted
by local land use or comprehensive plans. In summary;
• The use of standard rainfall runoff models with changed land cover conditions to
simulate future watershed development should be encouraged to predict future peak
flows and base flood elevations. These estimates should assume full build out as
predicted by local land use plans.
• Modelers should also consider increasing roughness coefficients within the hydraulic
analysis to simulate the continued growth of vegetation within the study area.
CRS Credit for Future Conditions Mapping
The Community Rating System (CRS) is summarized in the separate publication,
CRS Credit for Habitat Protection and explained in more detail in the CRS Coordinator's
Manual. Credit toward reducing flood insurance premiums is provided in communities that
implement floodplain management measures that are above and beyond the minimum require-
ments ofthe National Flood Insurance Program.
NFIP-ESA H&H Guidance - 8 - January 1, 2010 DRAFT
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As discussed above, floodplain management regulations using a floodplain map based on future
conditions is above and beyond the guidance in FEMA's Guidelines and Specifications for Flood
Hazard Mapping Partners. This can be credited by the CRS, provided:
- The hydrologic and hydraulic study techniques used are recognized in Guidelines and
Specifications. Atechnique that is not discussed there may be submitted to the FEMA
Regional Office for consideration for CRS credit.
- The study and floodplain map is adopted for use in the community's development
regulations. New buildings constructed in the regulatory floodplain must be protected to
the future condition's base flood elevation.
- A community may submit the study to FEMA for incorporation into the next scheduled
DFIRM update for that community.
- At each CRS cycle verification visit (generally every five years), the community must
document whether its regulatory floodplain data still reflect future conditions. For
example, a study based on a 20-year land use plan prepared in 1995 will no longer reflect
future conditions in 2015.
Regulatory floodplain maps based on future conditions hydrology are credited under Section
411.c. "Future conditions hydrology" is defined in the CRS Coordinator's Manual as changes in
watershed land use as discussed in the previous pages. If another technique is used to reflect
future conditions, an appropriate explanation can be submitted for consideration.
The amount of credit is based on the type of FIRM zone and the amount of the Special Flood
Hazard Area shown on the FIRM that is affected by the new study.
NFIP-ESA H&H Guidance - 9 - January 1, 2010 DRAFT
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Hydraulic Models
Several elements of the Biological Opinion address the selection of appropriate hydraulic
analysis techniques. This section reviews how this can be done.
Current Models
FEMA maintains a list of currently accepted hydraulic models for use in floodplain delineation
on its website at: httpa/www.fema.gov/plan/prevent/fhm/en_hydra.shtm. The currently accepted hydraulic models for floodplain mapping fall into one of three general categories: steady
one-
dimensional (1 D), unsteady 1 D, or unsteady two-dimensional (2D). Key features of each type of
model are shown in Table 2.
The importance of proper engineering judgment in determining the most appropriate hydraulic
model is underscored throughout Appendix C to Guidelines and Specifications. This judgment
should continue to be the primary factor driving model selection.
Model Description Geometry Advantages Disadvantages Type
Steady 1 D Unchanging flow Cross section • Easiest to set up and run • Simplifies flow processes
assumed to travel • Efficient mapping tool to 1 D unchanging in time
entirely in the • Does not capture
downstream direction complex overbank flow
processes
• Does not address overbank storage
Unsteady Changing flow (e.g., Cross section • More accurate timing of • Simplified flow processes
1 D inflow hydrograph) peak, especially where to 1 D
assumed to travel multiple sources of water .Requires specific data
entirely in the down- converge input to represent stream direction • Overbank and structure significant water flux into
flows can be simulated and out of overbank
using approximations at storage areas
locations entered by the .Less stable than steady
user models • Takes floodplain storage .Requires additional data
into account development,
hydrographs
Unsteady Changing flow 3D Digital • More realistic simulation of • More data intensive to
and steady assumed to travel elevation complex flow patterns build DEM
2D both downstream and model (DEM) (e.g., strongly meandering .More prone to instability laterally across the streams, overbank flows,
channel/floodplain flow compression at bridge 'Needs hydrograph for all
mayor tributaries piers)
Table 2. General characteristics of the three common types of hydraulic models
NFIP-ESA H&H Guidance -10 - January 1, 2010 DRAFT
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Another consideration for the selection of models is the level of precision that is required for the
results. In many instances, a less precise hydraulic method will still provide sufficient detail for
mapping floodplains, especially if appropriately conservative assumptions are made during the
modeling and mapping steps.
Regional Guidance
Guidelines and Specificaiions suggests the use of steady 1 D models, except when conditions are
too complex for these models to provide satisfactory answers. More complex hydraulic
approaches are used when there is reason to believe that a steady 1D model will not produce a
reasonable estimate of the base flood elevation. This guidance can be found in Section C3.4 of
Guidelines and Specificutions.
This Regional Guidance provides more specific advice for applying different models, but is not
intended to supersede the technical requirements for applyiqg a specific model provided in the
revised Appendix C to Guidelines and Specificutions.
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An unsteady 1D model was used by the Corps of Engineers to develop flood mapping for the Upper
Chehalis River. The Chehalis valley near Chehalis and Centralia is a hydraulically complex area that
includes the confluences of several major tributaries and significant floodplain storage volume. One
product is this map showing flood depths. The use of an unsteady 1 D approach in this location has
additional benefits in terms of supporting the design and analysis of potential flood mitigation
measures.
- NHC
NFIP-ESA H&H Guidance - I I- January 1, 2010 DRAFT
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Assessing the hydraulic aspects of the channel and floodplain: Several elements of the
Biological Opinion focus on requiring that the NFIP include measures to avoid, minimize, and
mitigate potential impacts to floodplain storage and physical habitat provided within the channel
and floodplain system. It calls for more complex hydraulic analyses to support the identification
of impacts and the determination of appropriate mitigation. Unlike steady-state hydraulic
models, unsteady-state models account for floodplain storage. In situations where storage is a
concern, unsteady-state models should be considered. The application of an unsteady 1 D model
will assist in:
- The identification of upstream and downstream impacts (e.g., stage, velocity, duration) of
floodplain alterations, and
- The development of appropriate and effective mitigation measures.
Some hydraulic systems are best represented by a 2D model. These instances include:
- Locations with uncertain and potentially changeable flow paths
- Bridges or other locations where flows experience significant lateral flow compression
- Estuaries with flow reversals
For example, the use of a 2D model is common for scour analyses at bridge piers and for the
design of fish habitat improvement proj ects. Flow surrounding bridge piers has a strong lateral
component which cannot be captured with a 1D approach. Similarly, a 2D model will be the
more appropriate choice to capture post-project conditions for habitat restoration projects that
include the use of engineered log jams to create more complex flow processes.
CRS Credit for Hydraulic Modeling
CRS credit is available for some higher study standards. However, this credit is not
provided where it is standard practice to use appropriate hydraulic analysis techniques for a
given situation, as specified in Guidelines and Specifications.
NFIP-ESA H&H Guidance -12 - January 1, 2010 DRAFT
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Channel Migration Zones
Background
Dynamic physical stream processes can
cause channels to move or "migrate" over
time. The azea within which a river
channel is likely to move over a period of
time is referred to as the channel migra-
tion zone (CMZ). Channel migration is a
severe hazard that converts normally dry
ground to a river bed, often by undercut- ting and destroying buildings, roads, and
infrastructure. The hydraulic models
. ~i
approved.in Guidelines and Specifica- tions do not reflect possible changes in $s a+
the channel bed during floods.
Keeping inappropriate development out of the CMZ will
prevent flood-related damage such as this. - Packwood, The NFIP-ESA Model Ordinance uses wasnington, danuary 2007
the term "channel migration area," which
is the mapped CMZ plus 50 feet. That is the area subject to the regulatory requirements of the
ordinance. This Regional Guidance deals with the hydrologic and hydraulic aspects of mapping
the CMZ. Once the CMZ is mapped, the area subject to regulations can be quickly delineated.
While a CMZ does not account for dynamic changes in the channel bed during floods, it does
delineate areas subject to the hazard. The CMZ is not mapped as part of a Fiood Insurance Study
and is not included on FIRMs, but it is appropriate to regulate and include within a community's
mapping database.
Biological Opinion Requirements
Identifying the extent of the CMZ is referenced in several parts of the 2008 Biological Opinion:
The FEMA will ensure that effects from habitat alterations that are reasonably certain to occur but
might occur later in time, such as changes in storm water quantity, quality, and treatment, decreased
riparian vegetation, lost large woody debris, increased bank armoring, and impaired channel
migration, are also mitigated. [page 1521
Bank stabilization measures along salmonid bearing streams, channel migration zones, and along
estuazine and marine shorelines must be minimized to the maximum extent possible. [page 224]
No acYivity is allowed that ]imits the natural meandering pattern of the channel migration zone,
however, natural channel migration patterns may be enhanced or restored [page 224]
The Biological Opinion calls for higher regulatory standards within the Regulatory Floodplain,
which includes the CMZ (page 154). Special rules apply in the Protected Area, wbich includes
the channel migration area (CMZ plus 50 feet). FEMA does not require the development of CMZ
NF]P-ESA H&H Guidance - 13 - January 1, 2010 DRAFT
DRAFT
mapping, but if mapping has been completed and adopted for local regulatory purposes before
September 22, 2008, then this designation shall be used to define the channel migration area.
If a community chooses to map and regulate the CMZ, the mapping should be developed
consistent with this Regional Guidance.
Regional Guidance
There are several methods of delineating a CMZ, ranging from approximate to more rigorous
technical methods. The Washington State Department of Ecology released a CMZ delineation
method in 2003, A Framework for Delineating Channel Migration Zones (Rapp and Abbe, 2003)
(referenced here as the 2003 Framework). The 2003 Framework was devised to provide a
technical framework for delineating the likely CMZ and is intended to be implemented by
experienced fluvial geomorphologists.
The 2003 Framework is the method cited in the Biological Opinion as the basis for determining
the location of the CMZ. It is also the method recommended for use by this Regional Guidance.
Key elements of the method are described here, but this discussion is not intended to provide all
of the detail offered in Rapp and Abbe 2003.
The `design life' (how long into the future the CMZ mapping is intended to capture) of the CMZ
mapping is an important consideration that will influence the applicability and use of the study
for use as the Regulatory Floodplain. The Biological Opinion specifies that a 100 year timeframe
be used. This 100 year time frame should be considered differently than the "100-year"
terminology typically used in floodplain management. In floodplain terminology "100-year" is
shorthand for an event with a one percent chance of occurring in any given year.
In CMZ delineation, a 100 year design life would establish the area the channel could occupy
assuming that current climatic conditions and channel processes continue to occur for the next
100 years. The 100 year design life can be expressed as the potential for migration within 50
years on either side of the existing channel. It is recognized that the relative hazards of migration
can significantly vary within the overall CMZ. Communities have, and will, implement variable
regulations within the CMZ.
The 2003 Framework identifies four generalized components of CMZ delineation. This approach
allows for a more detailed description of physical processes and provides a method to build on
each data collection step. Inmost cases, all of these components will need to be accounted for to
establish a CMZ delineation .These components are described in Table 3 on page 15 and shown
graphically on page 16.
A number of data sources are available to support this work, as shown in Appendix D of Rapp
and Abbe 2003. The 2003 Framework assumes that these sources will be used in conjunction
with some level of field data collection. There is a significant amount of interpretation necessary
to accomplish mapping of the various components of the CMZ. Judgments need to be made
about data quality at each step, as the resolution of the mapping will always be limited by a finite
amount of data.
NFIP-ESA H&H Guidance -14 - January 1, 2010 DRAFT
DRAFT
Element Description Notes Include in the mapped CMZ?
Historical Migration Zone The collective area the channel Dependent on extent and quality (HMZ) occupied in the historical record of past records, including
Government Land Office maps,
Also referred to as the and past aerial photographs Yes
Historical Channel
Occupation Tract (HCOT) see for example
GeoEngineers, 2003
Avulsion Hazard Zone The area not included in the Dependent on field measure-
(AHZ) HMZ that is at risk of avulsion ments and identification of
over the timeline of the CMZ vertical channel variation, bank stratigraphy, and the presence Yes
and location of relict channels
and secondary flowpaths on the floodplain
Erosion Hazard Area The area not included in the The EHA can result from either (EHA) HMZ or the AHZ that is at risk of erosion of the stream bank, or
bank erosion from stream flow or slope failures of the bank that Yes
mass wasting over the timeline occur after erosion of the toe
of the CMZ
Disconnected Migration The portion of the CMZ where Care needs to be taken to Area (DMA) man-made structures, such as assess (1) whether the man-
majorlevees and Interstate made structures will actually
highways, physically eliminate prevent channel movement (e.g.,
channel migration. In some are levees sufficiently engi- cases, alevee protects an area neered?) and (2) whether the
that is so important, it will structure, highway, or protected
warrant restoring a migrated area is so important that there is
channel to its earlier location. no doubt that after a flood, the Case-by-case channel would be restored to its
previous location. Clear evi-
dence of the presence of a DMA would include: Corps certified
levees and a local adopted
maintenance agreement that
states that flood fighting would occur and any damage repaired
to prevent channel migration.
Table 3. Elements of the overall CMZ (Rapp and Abbe, 2003).
Note 1- In the case where there are features of aquatic habitat existing landward of the levee footprint,
the study should show how the habitat would not be impacted by the selection of the levee as a boundary to CMZ hazards.
The resultant mapping can include ahazard-based treatment of likely CMZ areas. The approach
allows for a ranking of, for example, severe, high, moderate, and low hazard areas throughout the
CMZ. This ranking is allowed to be subjective, depending on the mapper's experience and
confidence after working through all of the delineation steps. The use of these designations is
optional and the criteria used to establish them can be determined by each community.
NFIP-ESA H&H Guidance -15 - January 1, 2010 DRAFT
DRAFT
While the map should show the 100-year design life channel migration zone, the communiry
may adopt only the high hazard portion for its channel migration development regulations. For
the purposes of the NFIP-ESA Model Ordinance, the Regulatory Floodplain is based on the
channel migration area, which is the channel migration zone adopted by the community for its
development regulations, plus 50 feet.
CRS Credit for Mapping Channel Migration Zones
~
Mapping channel migration zones is covered under the CRS credit for uncertain flow
path hazards, found in the Special Hazards Supplement to !he CRS Coordinutor's Manual. A
stream subject to channel migration is considered a movable bed stream. A separate supplement
is scheduled to be published in 2010.
Credit points for mapping a CMZ are provided if the community also has special development
regulations that protect new development from migrating stream channels. The NFIP-ESA
Model Ordinance does not include such regulations, as the CMZ is only used to help delineate
the Protected Area. Therefore, for CRS credit, the community must have additional CMZ
regulatory standards as well as a map prepared in accordance with these guidelines.
FLOW
bedr.o* ' - - -
Outcrop EHA
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AHZ
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0 1930 Active Channel ~ 1950 Active Channel _ 1960 Active Channel
~ 1970 Active Channel 95M 1980 Active Channel ~ 1980 Aclive Channel
~ 2000 Active Channel Hisiorical Migration Zonc --Avulsion Hazard Zone
Erosion:Hazaid Aiea (Erosioil Setback + Geotechnical Seiback)
~ Disconnected Migration Arga Final CMZ Delineation
Example figure of CMZ elements (Rapp and Abbe, 2003)
NFIP-ESA H&H Guidance - 16 - January l, 2010 DRAFT
DRAFT
The credit for CMZ mapping is provided if the local history of migration is "reflected in the
mapping process. For full credit, mapping must be based upon floodplain soils and historic
channel migration that indicate the probable extent of future migration." (Special Hazards
Supplement, page 30.) Any mapping that implements the 2003 Framework will receive full
credit under this element of the CRS.
Half the CMZ mapping credit can be provided when there are no studies that meet the criteria
above. Half credit is provided if a community uses a locally developed standard building setback
for unstudied streams in lieu of a detailed study by a developer. Such a locally developed setback
standard must be based upon data from the general area regulated.
NFIP-ESA H&H Guidance -17 - January 1, 2010 DRAFT
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Appendix A. References
Booth, D.B., D. Hartley, and C. R. Jackson. 2002. "Forest Cover, Impervious-Surface Area, and
the Mitigation of Stormwater Impacts." Journal of the American Water Resources Association.
Vol. 38: 835-845.
Brekke, L.D., Kiang, J.E., Olsen, J.R., Pulwarty, R.S., Raff, D.A., Turnipseed, D.P., Webb,
R.S.S., and White, K.D. 2009. Climate Change and Water Resources Management- A Federal
Perspective. U.S. Geological Survey Circular 1331. http://pubs.ugsg.gov/circ/1331/
Elsner, M.M., Cuo, L., Voisin, N., Deems, J.S., Hamlet, A.F., Vano, J.A., Nickelson, K.E.B.,
Lee, S-Y., and D.P. Lettenmaier. 2009. "Implications of 21St Century Climate Change for the
Hydrology of Washington State." Washington Climate Change Impacts Assessment Report.
FEMA. 2003. Guidelines and Specifications for Flood Hazard Mapping Partners. Volume 1:
Flood Studies and Mapping.
FEMA. 2002. Guidelines and Specifications for Flood Hazard Mapping Partners. Appendix C.
Guidance for Riverine Flooding Analyses and Mapping.
FEMA. 2008. Draft Guidelines and Specifications for Flood Hazard Mapping Partners.
Appendix C. Guidance for Riverine Flooding Analyses and Mapping.
Federal Emergency Management Agency (FEMA). 2001. Modernizing FEMA's Flood Hazard
Mapping Program: Recommendations for Using Future-Conditions Hydrology for the National
Flood Insurance Program.
FEMA. 2007. National Flood Insurance Program Community Rating System Coordinator's
Manual. FIA-15/2007. http://www.fema.gov/library/viewRecord.do?id=2434
FEMA 2006. Special Hazards Supplement to the CRS Coordinator's Manual.
http://training.fema.gov/emiweb/CRS/index.htm
FEMA, 2010, CRS Credit for Habitat Protection, http://training.fema.gov/EMIWeb/CRS/
FEMA 2010. NFIP-ESA Model Ordinance, www.
GeoEngineers, 2003. "Geomorphic Evaluation and Channel Migration Zone Analysis Puyallup,
Carbon, and White Rivers." Prepared for Pierce County Public Worka and Utilities
Environmental Services, Water Progams Division. June 19, 2003.
Grant, G.E., Lewis, S.L., Swanson, F.J., Cissel, J.H., McDonnell, J.J. 2008. Effects of Forest
Practices on Peak Flows and Consequent Channel Response: AState-of-Science Report for
Western Oregon and Washington. Gen. Tech. Rep. PNW.GTR-760, Portland, OR: U.S.
Department of Agriculture, Forest Service, Pacific Northwest Research Station.
NFIP-ESA H&H Guidance A -1 January 1, 2010 DRAFT
DRAFT
Herrera Environmental Consultants, Inc. Northwest Hydraulic Consultants, 2004. "Discharge of
Stormwater to High Order Streams: Determining Exempt Reaches." Prepared for Washington
State Department of Transportation. April 13, 2004.
Mote, P., Petersen, A., Reeder, S., Shipman, H., and L.W. Binder. 2008. Sea Level Rise in the
Coastal Waters of Washington State. University of Washington Climate Impacts Group and the
Washington State Department of Ecology. January 2008.
NMFS (National Marine Fisheries Service). 2008. Endangered Species Act -Section 7
Consultation Final Biological Opinion and Magnuson-Stevens Fishery Conservation and
Management Act Essential Fish Habitat Consultation. Implementation of the National Flood
Insurance Program in the State of Washington Phase One Document -Puget Sound Region.
September 22, 2008.
Rapp, C.F and T.B. Abbe. 2003. A Framework for Delineating channel migration zones.
Ecology Final Draft Publication #03-06-027. http://www.ecy.wa.gov/biblio/0306027.html
Rosenberg, E.A., Keys, P.W., Booth, D.B., Hartley, D., Burkey, J., Steinemann, A.C., and
Lettenmaier, D.P. 2009. Precipitation Extremes and the Impacts of Climate Change on
Stormwater Infrastructure in Washington State. Implications of 21St century climate change for
the hydrology of Washington State. Washington Climate Change Impacts Assessment Report.
March 2009.
Sturm, T.W. 2001.Open Channel Hydraulics. McGraw Hill, New York, NY.
Washington State Department of Ecology 2004. Stormwater Management Manual for Eastern
Washington. Publication Number 04-10-076.
Washington State Department of Ecology 2005. Stormwater Management Manual for Western
Washington. Publication Numbers 05-10-029 through OS-10-033.
NFIP-ESA H&H Guidance A - 2 January 1, 2010 DRAFT
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Appendix B. Flow Control-Exempt Surface Waters
(Appendix I-E to Stormwater 1~lanagement Manual for Western Washington)
Stormwater discharges that are otherwise subject to Minimum Requirement -Flow Control,
to waters on this list must meet the following restrictions to be exempt from Minimum
Requirement
- Direct discharge to the exempt receiving water does not result in the diversion of
drainage from any perennial stream classified as Types 1, 2, 3, or 4 in the State of Washington Interim Water Typing System, or Types "S", "F", or "Np" in the Permanent
Water Typing System, or from any category I, II, or III wetland; and
- Flow splitting devices or drainage BMP's are applied to route natural runoff volumes
from the project site to any downstream Type 5 stream or category IV wetland:
- Design of flow splitting devices or drainage BMP's will be based on continuous
hydrologic modeling analysis. The design will assure that flows delivered to Type 5
stream reaches will approximate, but in no case exceed, durations ranging from 50%
of the 2-year to the 50-year peak flow.
- Flow splitting devices or drainage BMP's that deliver flow to category IV wetlands
will also be designed using continuous hydrologic modeling to preserve pre-project
wetland hydrologic conditions unless specifically waived or exempted by regulatory
agencies with permitting jurisdiction; and
- The proj ect site must be drained by a conveyance system that is comprised entirely of
manmade conveyance elements (e.g., pipes, ditches, outfall protection, etc.) and extends
to the ordinary high water line of the exempt receiving water; and
- The conveyance system between the project site and the exempt receiving water shall
have a hydraulic capacity sufficient to convey discharges from future build-out
conditions (under current zoning) of the site, and the existing condition from non-project
areas from which runoff is or will be collected; and
- Any erodible elements of the manmade conveyance system must be adequately stabilized
to prevent erosion under the conditions noted above.
NFIP-ESA H&H Guidance B -1 January 1, 2010 DRAFT
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Exempt Surface Waters List
Alder Lake
Aston Creek Downstream of confluence with George Creek
Baker Lake
Baker River Baker River/Baker Lake downstream of the confluence with Noisy
Creek
Bogachiel River 0.4 miles downstream of Dowans Creek
Calawah River Downstream of confluence with South Fork Calawah River
Carbon River Downstream of confluence with South Prairie Creek
Cascade River Downstream of Found Creek
Cedar River Downstream of confluence with Taylor Creek
Chehalis River 1,500 feet downstream of confluence with Stowe Creek
Chehalis River, South Fork 1,000 feet upstream of confluence with Lake Creek
Cispus River Downstream of confluence with Cat Creek
Clearwater River Downstream of confluence with Christmas Creek
Columbia River Downstream of Canadian border
Coweman River Downstream of confluence with Gobble Creek
Cowlitz River Downstream of confluence of Ohanapecosh River and Clear Fork
Cowlitz River
Crescent Lake
Dickey River Downstream of confluence with Coal Creek
Dosewallips River Downstream of confluence with Rocky Brook
Dungeness River Downstream of confluence with Gray Wolf River
Elwha River Downstream of confluence with Goldie River
Grays River Downstream of confluence with Hull Creek
Green River (WRIA 26 -Cowlitz) 3.5 miles upstream of Devils Creek
Hoh River 1.2 miles downstream of Jackson Creek
Humptulips River Downstream of confluence with West and East Forks
Kalama River 2.0 miles downstream of Jacks Creek Lake Cushman
Lake Quinault
Lake Shannon
Lake Sammamish
Lake Union & Union Bay King County
Lake Washington, Ship Canal, & Salmon Bay
Lake Whatcom
Lewis River Downstream of confluence with Quartz Creek
Lewis River, East Fork Downstream of confluence with Big Tree Creek
Lightning Creek Downstream of confluence with Three Fools Creek
Little White Salmon River Downstream of confluence with Lava Creek
Mayfield Lake
Muddy River Downstream of confluence with Clear Creek
Naselle River Downstream of confluence with Johnson Creek
Newaukum River Downstream of confluence with South Fork Newaukum River
Nisqually River Downstream of confluence with Big Creek
Nooksack River Downstream of confluence of North Fork and Middle Forks
NFIP-ESA H&H Guidance B - 2 January 1, 2010 DRAFT
DRAFT
Nooksack River, North Fork Downstream of confluence with Glacier Creek, at USGS gauge
12205000
Nooksack River, South Fork 0.1 miles upstream of confluence with Skookum Creek
North River Downstream of confluence with Vesta Creek
Ohanapecosh River Downstream of confluence with Summit Creek
Puyallup River Half mile downstream of confluence with Kellog Creek
Queets River Downstream of confluence with Tshletshy Creek
Quillayute River Downstream of Bogachiel River
Quinault River Downstream of confluence with North Fork Quinault River
Riffe Lake
Ruby Creek Ruby Creek at SR-20 crossing downstream of Granite and Canyon
Creeks
Satsop River Downstream of confluence of Middle and East Forks
Satsop River, East Fork Downstream of confluence with Decker Creek
Sauk River Downstream of confluence of South Fork and North Fork
Sauk River, North Fork North Fork Sauk River at Bedal Campground
Silver Lake Cowlitz County
Skagit River Downstream of Canadian border
Skokomish River Downstream of confluence of North and South Fork
Skokomish River, South Fork Downstream of confluence with Vance Creek
Skokomish River, North Fork Downstream of confluence with McTaggert Creek
Skookumchuck River 1 mile upstream of Bucoda at SR 507 mile post 11.0
Skykomish River Downstream of South Fork
Skykomish River, South Fork Downstream of confluence of Tye and Foss Rivers
Snohomish River Down stream of confluence of Snoqualmie and Skykomish Rivers
Snoqualmie River Downstream of confluence of the Middle Fork
Snoqualmie River, Middle Fork Downstream of confluence with Rainy Creek
Sol Duc River Downstream of confluence of North and South Fork Soleduck River
Stillaguamish River Downstream of confluence of North and South Fork Stillaguamish River, North Fork highway miles west of Darrington on SR 530, downstream of
confluence with French Creek.
Stillaguamish River, South Fork Downstream of confluence of Cranberry Creek and South Fork
Suiattle River Downstream of confluence with Milk Creek
Sultan River 0.4 miles upstream of SR2
Swift Creek Reservoir
Thunder Creek Downstream of the confluence with Neve Creek
Tilton River Downstream of confluence with North Fork Tilton River
Toutle River North and South Fork Confluence
Toutle River, North Fork Downstream of confluence with Hoffstadt Creek
Toutle River, South Fork Downstream of confluence with Thirteen Creek
White River Downstream of confluence with Huckleberry Creek
Willapa River Downstream of confluence with Mill Creek
Wind River Downstream of confluence with Cold Creek
Wynoochee Lake
Wynoochee River Downstream of confluence with Schafer Creek
NFIP-ESA H&H Guidance B - 3 January 1, 2010 DRAFT