HomeMy WebLinkAboutPlanning 2019-05-23 Item 5 - Attachments - Critical Areas Code DeliberationsTo:
[hhstv0'Rahertv ,
RE: Planning [ommisionComments
From: donaNscan/o
Sent: Wednesday, April 10,ZU192:S7Pk8
To/Tukwila City Oerk�[u�wi���y�}erk��TukY»i�amA��ou^Subject: Planning Commision Comments
I plan to attend the planning commission meeting Thursday night. In case I can't make it please enter these comments.
K1yconcern is with the deletion ofitem 8under section 18.45.110.This states culverts shall boupgraded when being re-
developed orwhennowdove|opment000ure./dnn'tmeeanything|ikethiointhenewseotion18.45.11O.Thenewdreftio
only focused on piping streams. |tdoesn't address when and vvhena streams should be opened up or improved. | would
like tosee the old item eight be retained.
Don Scanlon
This email originated from outside the(]tvofTuhwihnetwork.PleaseDONQTnpenattachmentsordick
links from anunknown orsuspicious origin.
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21
52 2ncl Ave.. DU0O 500
Seattle. WA9810-1
wvp,v.cairncross,com
April 10, 2019
VIA HAND DELIVERY
office 206.587.0700
ax 206.587.2308
City of Tukwila Planning Commission
City of Tukwila
6300 Southcenter Blvd., #100
Tukwila, WA 98188
Re: Comments on Proposed Critical Areas Code Update L18-0056
Dear Planning Commissioners:
This firm represents Segale Properties LLC ("Segale"). As you are likely aware, Segale controls the
large Tukwila South property, abutting the Green River. In 2009, Segale and the City entered into a long-
term Development Agreement governing the future building on the Tukwila South property. After years of
construction to install all necessary infrastructure and re -grade the property for development, the Tukwila
South lands are finally ready to be marketed and are being actively reviewed for ground lease and/or sale for
commercial and residential buildings and development.
In addition to the Development Agreement, on June 8, 2009, the City Council approved the entire
Tukwila South property as a Sensitive Area Master Plan Overlay District. Segale implemented a Sensitive
Areas Master Plan ("SAMP") that addressed the entire 512-acre Tukwila South site, authorizing alterations
and mitigation of sensitive areas, in a comprehensive plan that overall improved water quality, fish and
wildlife habitat and hydrology beyond what would have occurred through the strict application of the
provisions of the Sensitive Areas Ordinance. The SAMP assured protection of the Tukwila South lands'
sensitive areas and buffers by locating them in Native Growth Protection Areas ("NGPAs"), and SAMP
Condition 18 required that the NGPA protections be assured via recorded instruments on the real property
title. Tukwila South also is in the process of being subdivided with final plats being recorded on a phased
basis, and each final plat locates NGPA areas in a protected tract.
The NGPAs are mapped on Exhibit 3 to the Development Agreement. Exhibit 3 plainly labels the
NGPAs as "Non -Development areas," in contrast to the remainder of the Tukwila South lands which are
the "Development Areas," and Section 3.2 of the Development Agreement authorizes 100% of the
Development Areas to be cleared and graded, and up to 85% of the Development Areas served by each
stormwater facility to be covered with impervious surfaces. Likewise, Section 5.1 of the Development
EXHI
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nroversacairncross.ccm
direct: (206) 254-4417
{03 707102.DOCX; I
22
City of Tukwila Planning Commission
April 10, 2019
Page 3
assessed and evaluated, and sensitive areas are generally set aside in protected tracts. In fact, TMC
18.45.170, Critical Areas Tracts and Easements, requires that critical areas on a development site be
protected in a tract or easement that must remain undeveloped in perpetuity. Importantly, applications
for building permits cannot be made until after a subdivision or binding site plan is approved, because
under RCW 19.27.095(2)(a), one cannot apply for a building permit without a legal parcel. This means
that one cannot file and vest a building permit application for a new home or commercial building in a
new subdivision, until after the final plat has been recorded. It is also generally the case that buildings
in a subdivision are not all constructed immediately or all at once, but rather over the course of at least
five years.
As drafted, it is not clear that the new vesting provision assures a landowner who applies for and
designs a preliminary plat to protect critical areas in tracts, can apply for later building permits relying
on those tract boundaries. This is a problem because a new, larger buffer width could easily eliminate
the building area on one or more of the new lots and destroy the landowner's investment value. We
recommend the City amend the vesting policy to clarify that future building permits in a subdivision or
binding site plan are vested to the critical area provisions in effect at the time of application for the
preliminary subdivision or preliminary binding site plan was made, and that vesting remains in effect for
a period of five years following the recording of the final plat or final binding site plan. Suggested
revisions to TMC 18.45.190.0 are:
C. Vesting: Projects are vested to the critical area ordinance in effect at the time a
complete building permit is submitted except for short plats, subdivisions, binding site
plans, and shoreline permits. Short plats or subdivisions or binding site plans are vested
to the critical area ordinance in effect at the time complete application is submitted for
preliminary plats or for the binding site plan. The final plat. final site plan. and all future
building permits on the lots remain vested to that same critical areas ordinance in effect
for the preliminary plat or Drelimin bindina site Ian a lication. so long as buildin
permits are a Dlied for within five ears of the final.plat or site nlan an royal. For short
plats and subdivisions which received preliminary plat approval prior to the adoption of
this ordinance, building permits on the lots shall be considered under the critical areas
ordinance in effect on the date of the preliminary plat : application provided
complete building or construction permits are submitted within ene five years of the final
plat approval. Vesting provision for shoreline permits are provided in TMC 18,44.
Again, while this vesting regulation does not affect Segale's Tukwila South lands, we highly
recommend these clarifying amendments to ensure protection of Tukwila landowners.
(03707 102.DOCX;1 }
23
To:
Minnie Dha|kwa/
RE: Tukwila's Critical Areas Code amendments, Chapter 18.45, Public Notice
From: Minnie Dha/kmo|<K4innie.Dha|kwa!@r[ukmitaVVA.8nv>
`
Sent: Thursday, April 1l2O193:44PM
To: VVynettaBixens<VVynetta.8kens@Tukwi|aVVA.gov>
Cc: Jack Pace "1ack.Pace @Tukvxi|aVVA.gnv>
Subject: Fw: Tukwila's Critical Areas Code amendments, Chapter 18.45, Public Notice
From: Karen Walter <KVValter(@muck|
Sent: Wednesday, April 1(\ZO198:17AK4
To:[htica|4reas
Subject: FW: Tukwila's Critical Areas Code amendments, Chapter 18.45, Public Notice
KarenVVaher
`4Vatershedsand Lancl, Use Team Leader
wuckleshontIndian Tribe Fisheries Division
*obitot'p,ogrom
3soz5.4zrz""Ave ss
Auburn, wweoosz
253'87s'3116
From: Karen Walter
Sent: Tuesday, April 09/2019 12:29 PM
To: 'CritiCGl8[88@TUkVVlaWA.gOV'
Cc: 'MiOOi2[)hnliV8y
Subject: Tukwila's Critical Areas Code amendments, Chapter 18.45, Public Notice
To Tukwila staff,
We have reviewed the propose amendments to the City of Tukwila's Critical Areas Code and have
questions/comments as noted:
Currently, there is nothing in the City's code to require that watercourses be classified using current
information and field data like there isfor wetlands. The City should amend the code torequire that all
available information be used along with field data toverify watercourse classification. This is an important
24
We appreciate the opportunity to review these code amendments. If you have any questions, please let me
know.
Thank you!
Karen Walter
Watersheds and Land Use Team Leader
Muckleshoot Indian Tribe Fisheries Division
Habitat Program
syozs,*z7z"Ave SE
Auburn, ww98092
253'876`3116
CAUTION: This email originated frommoutsidethe[itxofTukvv|anetvvork.P|easeDO NOT open attachments
orclick links from anunknown orsuspicious origin.
25
Comments to City of Tukwila Critical Area code update
Submitted at Public Meeting on April 11, 2019, City of Tukwila
by Ion Manea, owner of 13407 48th Av S, Tukwila, WA., 98168 property
Re: Critical Areas
The proposed TMC 18.45.100 E replace "sensitive area" with "critical area".
However there is no definition of "critical area" in the TMC.
Please update definition accordingly.
Re: Critical Area Map TMC 18.45.30 G. 1.
The current TMC 18.45.30 G. 4 states:
" Regardless of whether a sensitive area is shown on the sensitive areas map, the actual
presence or absence of the features defined in the code as sensitive areas shall govern. The
Director may require the applicant to submit technical information to indicate whether sensitive
areas actually exist on or adjacent to the applicant's site, based on the definitions of sensitive
areas in this code."
The proposed code change eliminates TMC 18.45. G. 1. provision and the following is inserted
in TMC 18.45.30. G 1:
"Not all critical area are shown on the map, it is the applicant responsibility to verify actual
presence or absence of critical area or critical area buffer based on the definition of this code."
There is no mechanism to require correct errors or make updates if circumstances change.
Please include a provision that if the actual presence or absence of critical area is
verified, that finding shall govern and shall be incorporated in all revisions, updates and
reprinting of sensitive areas maps, inventories, ratings and buffers.
Re: Watercourse buffers TMC 18.45.100 E
Pursuant to RCW 36.70A.172 in designating and protecting critical areas counties and cities
shall include the best available science (BAS) in developing policies and development
regulations to protect the functions and values of critical areas.
An update to TMC 18.45 is proposed based on planning department work augmented by public
inputs.
Substantial assistance was provided by BAS review and gap analysis report (Report)
prepared by The Water Shed Company (Consultant).
Although the BAS presented in the report or its references are not specific on watercourse
buffer reductions, the Consultant is recommending:
....reductions of up to 25 percent with enhancement are likely to provide adequate protection for
most small stream channels...
and
, for consistency with the wetland regulations, the City may consider utilizing buffer averaging
only
26
Re: TMC 18.45.180 4. f
There is a new requirement stating that:
"All unavoidable impacts are fully mitigated"
The statement is confusing. The whole purpose of reasonable use exception is to address
expressly the exceptional situation in which mitigation alternatives have been exhausted.
Requiring full mitigation of impacts will practically exclude the use of reasonable use exception
permitting alternative.
It will be more appropriate to exclude this provision.
Re: TMC 18.45.195 D 4.
There is no justification of establishing a minimum penalty of $ 1,000 per tree regardless of the
tree size and marketable value of each tree.
It will be more appropriate that penalty to be "up to the marketable value of the tree"
established by a certified professional.
Ion Manea
Property owner, 13407 4th Av S, Tukwila, WA., 98168
Date: 04.11.2019
27
WATER RESOURCE
MIA DOWANSH
ANO
A TEI11311E11
of
WthdMa
.r11-1,111Cerilera
INVENTORY AREA 9 (WRIA 9) WATERSHED ECOSYSTEM FORUM
April 11, 2019
SMP Periodic Update
Department of Community Development
6300 Southcenter Bl. Suite 100
Tukwila, WA 98188
COUNTY
Re: City of Tukwila Shoreline Management and Critical Areas Ordinance 2019 updates —
Comments from WRIA 9
Dear City of Tukwila,
Below are WRIA 9 staff comments on the City of Tukwila's 2019 Shoreline Management
(Tukwila Municipal Code 18.44) and Critical Areas Ordinance (Tukwila Municipal Code 18.45)
updates.
GENERAL COMMENTS:
• We are encouraged to see various incentives being used to increase the likelihood that
shoreline restoration activities will occur.
• The Green/Duwamish River is a Shoreline of Statewide Significance. Jurisdictions
along the river are obligated to manage this shoreline with consideration to the
interests of their residents and all citizens of the state. We encourage the City to
approach any suggested changes to this update with this responsibility in mind.
• We commend the City for specifically referencing the 2005 WRIA 9 Salmon Habitat
Plan that Tukwila ratified. The 2014 Duwamish Blueprint and the 2005 Salmon
Habitat Plan are policy and programmatic guides for shoreline management in the city
and should be used to guide shoreline restoration, protection, land use, and
regulations. WRIA 9 is currently updating the Plan to reflect new science,
programmatic and policy changes, and capture completed and new high priority
capital projects within the watershed. The updated plan is expected to be adopted in
2020 by the Watershed Ecosystem Forum, followed by ratification by all the cities
which are party to the WRIA 9 Interlocal Agreement. We recommend including
language that accommodates addendums and updates to the plan (e.g., Duwamish
Blueprint), and any projects therein. WRIA 9 staff would be happy to assist in crafting
appropriate language to include in this update.
SECTION SPECIFIC COMMENTS:
• Section 18.44.060 there is language about thinning restoration plantings under "4.
Restoration Project Plantings". We recommend adding language about the purpose of
thinning for these densely planted restoration sites. The purpose should be to
improve plant survival and health if dense planting is causing negative implications
from competition.
EXHIBIT
PiROJEpT N
FILE NO
28
Thank you for the opportunity tocomment. Please direct any questions about these
comments to me. My contact information is below.
Sincerely,
8uznuoaSuzitb
8ozmoou8nuith
Habitat Projects Coordinator
Greeo/Dunonoisb&Central Puget Sound Watershed (WQlA9)
201South Jackson Street, Suite 6O8
Seattle, VVA08l04'38S5
sosmithPkingcuunt guv
Office: (2U6)477'4641,Cell: (206)3OS'1752
29
City of Tukwila Shoreline Management and Critical Areas Ordinance 2019 updates — comments from
King County Noxious Weed Program 4/11/19
What follows are the King County Noxious Weed Control Program's comments on the City of Tukwila's
2019 Shoreline Management (Tukwila Municipal Code 18.44) and Critical Areas Ordinance (Tukwila
Municipal Code 18.45) updates, Our notes are in "Comments" to the right of the pertinent text. Questions
about these comments should be sent to:
Ben Peterson
Aquatic Noxious Weed Specialist
King County Noxious Weed Control Program
(206) 477-4724
ben.peterson@kingcounty.gov
wwww,kin:.cotunty.eoviweeds
18.44.080060 Vegetation Protection and Landscaping
A. Purpose, Objectives and Applicability. (Page 27)
5. Minor Activities Allowed without a Permit or Exemption,
a. The following activities are allowed without a permit or exemption:
(1) Maintenance of existing, lawfully established areas of crop vegetation, landscaping
(including paths and trails) or gardens within a regulated critical area or its buffer. Examples
include, mowing lawns, weeding, harvesting and replanting of garden crops, pruning, and
planting of non-invasive ornamental vegetation or indigenous native species to maintain the
general condition and extent of such areas. Cutting down trees and shrubs within a buffer is not
covered under this provision, Excavation, filling, and construction of new landscaping features,
such as concrete work, berms and walls, are not covered in this provision and are subject to
review,
(2) to'tious weed control within vegetative buffers, if work is selective only for noxious
species; is done by hand removal/spraying of individual plants; spraying is conducted by
licensed applicator; and no area -wide vegetation removal or grubbing is conducted. Control
methods not meeting these criteria may still apply for a restoration exemption, or other
authorization as applicable.
D. Vegetation Management in the Shoreline Jurisdiction. The requirements of this section apply to
all existing and new development within the shoreline jurisdiction. (Page 33)
3. Use of pesticides.
a. Pesticides (including herbicides, insecticides, and fungicides) shall not be used in the shoreline
jurisdiction except where:
(1) Alternatives such as manual removal, biological control, and cultural control are not
feasible given the size of the infestation, site characteristics, or the characteristics of the
invasive plant species;
EXHIPROJ
Commented [PB1]: This is nicely worded.. -You may want
to add that the "licensed herbicide applicator" needs to
have the required aquatic herbicide permits from WA
Ecology if the application occurs in a an aquatic site.
30
(2) The use of pesticides has ]n approved through a comprehensive vegetation
or pest management and monitoring plain
(3) The pesticide is applied in accordance with state regulations,
(4) The proposed herbicide is approved for aquatic use by the U.S.
Environmental Protection Agency; and
(5) The use of pesticides in the shoreline jurisdiction is approved in writing by
the City{ and the applicant presents a copy of the Aquatic Pesticide Permit issued
by the Department of Ecology or Washington Department of Agriculture. (Page
18-164)
Commented [PB8]: "..or a Ring County Noxious Weed
Control Program Best Management Practices document"
Commented [PB9]: Since herbicide use in shoreline and
aquatic areas is already carefully regulated by the WA Dept.
of Ecology and the WA Dept. of Agriculture, we feel that it is '..
redundant and unnecessary to require additional approval
from the City of Tukwila for use of this weed control
method.
31
Reply e|etu junk|�
'
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Vesting and the MOU[)dGfe3
� KJ8n[VRogers �KjRnoe[S��Ca/[Dc[oSS,[oryl>
Minnienlha|ivval; moraGiedoff 8
You forwarded this -nessage on 4/12/2019 1:30 PM
HiMinnieandNoo—
*� Reply ! v
4
You have my letter dated April 10, 2019 regarding potential revisions to vesting language for the CAO issues. During
last night's hearing on the CACt, Minnie explained that the vesting language in the CAO was not linked to any
shoreline permits, If that is true, and in light of State law that gives a Shoreline permit a 5 year term, subject to
possible extension, I recommend that the City add a vesting provision to the Shoreline regulations. The provision to
add to the Shoreline regulations would assure that in the situation where a project is staged orphased into first land
development, followed by a building permit (or permits), those later building permits are vested to the version of the
shoreline regulations that were in effect when the land development permits were applied for,
Let me know if you have questions.
Thanks'
Nancy
('H&� I NoocyBainbridge Rogers
�,�rurr°�nx�lfonny,l,ou"x
524Second A,cnncSoie5OOSxm.|c\V\98{04-2323
d: 206^254-44i7�[206'587'2308
1)y 2016 and C1,eanbeav1,<�zl 20INill the area nf,Wamkngroii Staba]RamlEstate:
Dwa
CH& is a member oFNlackrell International, a Global Network of Independent L,aiv Firms.
mmemail message may mntamconfidential wdpwiiegod informam�IF-you are c,otthe
mwxa*delete the original message 011thmureading. mscins0oOr co,yifioit's Contents, ���
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attachments or click links from an unknown orsuspicious origin.
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32
Matrix of Proposed 18.45 Edits
Row
Number
Section
Requested Change
Comment Summary/Staff Discussion
Source
Staff Recommendation
1
18.45.110
Retain the following subsection of 18.45.110: On properties being developed or re -developed, or when stream
crossings in public or private rights -of -way are being replaced, existing culverts that carry fish -bearing
watercourses or those that could bear fish (based on the criteria in WAC 222-16-031, Washington Forest Practices
Rules and Regulations), shall be upgraded to meet the standards in the WDFW manual "Design of Road Culverts
for Fish Passage" (2003 or as updated) if technically feasible.
Don Scanlon requested to retain this section and address when and where
streams should be opened up or improved.Additionally, Tukwila's Public
Works staff recommended retaining this section.This section has been
reinstated and the entire TMC 18.45.110 Watercourse Alterations sections
has been rewritten to clarify criteria for approving culvert replacement, day-
lighting, and piping/dreding/diverting/rerouting. The referenced 2003
manual is now referenced 2013 manual.
Exhibit 1
Make the requested change and
amend the entire watercourse
alteration section to clarify different
types of alterations and criteria of
approval for each. See entire TMC
18.45.110 for all the proposed
changes. This section is highlighted in
the underline/strikeout version
included as Attachment E.
2
18.45.160
Add a subsection to TMC 18.45.160, Critical Area Master Plan Overlay, to read: " The boundaries of critical areas
and associated buffers, which critical areas were created or enhanced pursuant to an approved Critical Area
Master Plan or Sensitive Area Master Plan are not subject to expansion due to the later adoption of increased
buffer widths into this Critical Areas Ordinance, the Shoreline Overlay regulations or any updates thereto."
Nancy Rogers, representing Segale Properties requested amendments to
the Critical Areas Master Plan Overlay Section. The proposed new language
would vest any future development for perpetuity. Staff is still researching
the topic of vesting as it relates to Critical Area Master Plan Overlay and will
come back to the Planning Commission with a recommendation at the next
meeting.Additionally, TMC 18.45 only addresses Critical Areas. TMC 18.44
SMP addressed comments related to vesting to Shoreline regulations.
Exhibit 2
Deferred to the next Planning
Commission meeting.
3
18.45.190.0
Amend the proposed Vesting Section: Projects are vested to the critical area ordinance in effect at the time a
complete building permit is submitted except for short plats, subdivisions, binding site plans and shoreline
Nancy Rogers, representing Segale Properties requested amendments to
the vesting section to add clarity; include adding binding site plan to the list
of short plat and subdivision; and increase the time frame from one year to
five years to apply for buiding permits from the time of final plat/short
plat/binding site approval. Staff agrees with the proposed revisions, except
that Tukwila does not have site plan approval process (shown in green).
Exhibit 2
Make changes noted in red but not in
green font
permits. Short plats or subdivisions or binding site plans are vested to the critical area ordinance in effect at the
time complete application is submitted for preliminary plats or for the binding site plan. The final pEat, final site
pEan, and all future building permits on the lots remain vested to that same critical areas ordinance in effect for
the preliminary plat or preliminary binding site plan application, so long as building permits area ied for within
five years of the final plat orsiteplanapproval _For short plats and subdivisions which received preliminary plat
approval prior to the adoption of this ordinance, building permits on the lots shall be considered under the critical
in the date the building
areas ordinance effect on of preliminary plat approval application provided complete or
construction permits are submitted within eee five years of the final plat approval. Vesting provisions for shoreline
permits are provided in TMC 18.44
33
Row
Number
Section
Requested Change
Comment Summary/Staff Discussion
Source
Staff Recommendation
4
18.45.100 and 18.45.030
18.45.100. A. WATERCOURSE RATINGS. Watercourse ratings are consistent with the Washington Department of
Natural Resources water typing categories (WAC 222-16-030) or as amended, which are based on the existing
habitat functions and classified as follows...
18.45.030. E. CRITICAL AREAS MAPS AND INVENTORIES
1.The distribution of many critical areas and potential critical areas in Tukwila is displayed on the Critical Areas
Maps, on file with the Department of Community Development (DCD). These maps are based on site assessment
of current conditions and review of the best available scientific data and are hereby adopted by reference. Not all
critical areas are shown on the map. Thus, it is the responsibility of property owners and applicants to verify actual
presence or absence of a critical area or critical area buffer based on the definitions in this code. Applicant is also
esponsible for delineation and categorization of potential wetland based on methodology required under TMC
Karen Walter, representing Muckelshoot Indian Tribe requested a section
be added that requires watercourses be classified using current information
and field data similar to wetlands. Currently streams that have artificial
barriers on them are considered non-fishbearing due to lack of fish
presence. Instead they should be evaluated for fish habitat potential using
the WAC 222-16-031. Also, requested regular updates to the city's critical
areas maps for watercourses to include more recent field data and after
barrier culverts are removed. She also noted that Washington Department
of Fish and Wildlife (WDFW) is updating the State barrier data frequently
and their map should be consulted. Staff notes that the proposed changes
to TMC 18.45.100. (A) reference WAC 222-16-030. Additionally, TMC
18.45.030 could be amended to require applicants to use WAC 22-16-030
for watercourse typing and location as part of their proposal. Additionally,
staff appreciates Karen's guidance on using WDFW data for updates to the
city's critical area maps. Staff will explore options to update the
watercourse inventory maps congruent with the City's Surface Water
Comprehensive Plan update and look for opportunities during review of
development projects to add updated information to the inventory maps.
Exhibit 3
Make changes noted in red
18.45.80 and verifying that watercourse typing and location is consistent with TMC 18.45.100.
5
18.45.100.E.1.g
TMC 18.45.100.E. VARIATION OF STANDARD WATERCOURSE BUFFER WIDTH —
1 Buffer averaging may be allowed by the Director as a Type 2 decision if the total area of the buffer after
averaging is equal to the area required without averaging and the buffer at its narrowest point is never less than
either % of the required width; and the following criteria is met:
a. The watercourse has significant differences in characteristics that affect its habitat functions, and the buffer is
increased adjacent to the higher -functioning area of habitat or more -sensitive portion of the watercourse and
decreased adjacent to the lower -functioning or less -sensitive portion as demonstrated by a critical areas report
from a qualified professional.
b. There are no feasible alternatives to the site design that could be accomplished without buffer averaging, and
the averaged buffer will not result in degradation of the watercourse's functions and values as demonstrated by a
critical areas report.
c. Compliance with mitigation sequencing requirements.
d. Compliance with TMC 18.45 Vegetation Protection and Management section.
e. Submittal of buffer enhancement plan, mitigation monitoring and maintenance plan along with financial
guarantee in accordance with TMC 18.45.
f. Buffer averaging will not adversely affect water quality.
Karen Walter, Muckleshoot Indian Tribe noted that the need to increase
buffers on watercourses should include those necessary to improve water
temperatures as described under any state/federal water quality
improvement plans such as Toral Maximum Daily Load (TMDL) plans. Staff
has added a reference to TMDL for buffer averaging.
Exhibit 3
Makes changes noted in red.
No adverse affect to water temperature or shade potential will occur to watercourses using methodology per
2011 Washington State Department of Ecology's Green River Temperature Total Maximum Daily Load (TMDL}
assessment or as amended.
34
Row
Number
Section
Requested Change
Comment Summary/Staff Discussion
Source
Staff Recommendation
6
18.45.110.C.1).f
f. If onsi e mitigation is not ossible and to ensure there is no net loss of watercourse unctionsjpciudinout not
Karen Walter, representing Muckleshoot Indian Tribe requested that in
limited cases the city should allow the applicants to pay into aN in -lieu fund
to ensure that projects are fully mitigated for additional piping or culvert
work and for those instances when an applicant is daylighting stream
sections but cannot provide fully regulatory compliant stream buffers. This
should help ensure that there is no net loss of important stream functions
such as shading and future wood recruitment that might otherwise be lost if
no mitigation is required. Staff is proposing language be added to
Watercourse Mitigation Standards section to include option for in -lieu fund.
Exhibit 3
Make changes noted in red
limited to shading, the applicants may pay into an in lieu fund if available to ensure that projects are fully
mitii
7
8
18.45.30.E.3
18.45.100E
As new environmental information related to critical areas becomes available, the Director is hereby designated
to periodically add, remove or alter add new information to the Critical Areas Maps. Removal of any information
Ion Manea, property owner expressed concern that there is no mechanism
to require corrections to errors or updates if circumstances change. He
requested a provision be added that if the actual presence or absence of
critical area is verified, that finding shall govern and shall be incorporated in
all revisions, updates and reprinting of sensitive areas maps, inventories,
ratings and buffers. Staff notes that there is language under TMC
18.45.30.G.3 that addresses concerns raised by Mr. Manea.
Exhibit 4
Make changes noted in red to add
clarity.
from the critical area maps is a Type 1 decision.
VARIATION OF STANDARD WATERCOURSE BUFFER WIDTH
1 Buffer averaging may be allowed by the Director as a Type 2 decision if the total area of the buffer after
averaging is equal to the area required without averaging and the buffer at its narrowest point is never less than
either % of the required width; and the following criteria is met: a. The
watercourse has significant differences in characteristics that affect its habitat functions, and the buffer is
increased adjacent to the higher -functioning area of habitat or more -sensitive portion of the watercourse and
decreased adjacent to the lower -functioning or less -sensitive portion as demonstrated by a critical areas report
from a qualified professional. b.There
are no feasible alternatives to the site design that could be accomplished without buffer averaging, and the
averaged buffer will not result in degradation of the watercourse functions and values as demonstrated by a
critical areas report. c. Compliance
with mitigation sequencing requirements. d. Compliance
with TMC 18.45 Vegetation Protection and Management section.
e.Submittal of buffer enhancement plan, mitigation monitoring and maintenance plan along with financial
guarantee in accordance with TMC 18.45.
f. Buffer averaging will not adversely affect water quality.
g. No adverse effect to water temperature or shade potential will occur to watercourse using methodology per
2011 Washington State Department of Ecology's Green River Temperature Total Maximum Daily Load (TMDL)
assessment or as amended.
Ion Manea, property owner requested the city to keep 50% buffer reduction
provisions as the proposed provisions of 25% reduction with buffer
averaging is not based on best available science, and is being proposed just
for consistency with wetland regulations. He claims that the proposed
regulations could be construed as in non-complicnace with TMC 18.45.10,
18.45.20 and RCW 36.70a.172 and could be subject of a petition under
RCW.36.70A.290. Staff notes that 2011 Washington State Department of
Ecology's Green River Temperature Total Maximum Daily Load (TMDL)
assessment is Best Available Science that justifies larger buffers and need
for shading the streams to address the concern of raising temperature of
the Green/Duwamish River, which is detrimental to fish. Additionally,
Washington State Department of Ecology's guidance for the streams that lie
within Shoreline Zone is for buffer averaging rather than buffer reduction.
Exhibit 4
No change
35
Row
Number
Section
Requested Change
Comment Summary/Staff Discussion
Source
Staff Recommendation
9
18.45.110B.2
3.Piping, dredging, diverting or rerouting of any watercourse should be avoided. Relocation of a watercourse or
installation of a bridge is preferred to piping. If piping occurs in a watercourse critical area, it shall be limited to the
degree necessary for stream crossings for access and may only occur with the permission of the Director as a Type
2 decision and subject to mitigation sequencing; approved mitigation plan; and the following criteria:
a)Any watercourse alteration shall comply with the standards in current use and the standards of the Washington
Department of Fish and Wildlife in the "Water Crossing Design Guidelines" manual (2013 or as amended).
b)Any watercourse alteration shall not cause adverse impacts to fish, confine the channel or floodplain, or
adversely affect riparian habitat (including downstream habitat). c) thru j)
Ion Manea requested to remove "confine the channel or flood plain" as
allowed alterations like crossing and culverts will confine the channel or
flood plain. Staff notes that any new crossing and culverts are required to
meet WDFW's Water Crossing Design Guidelines so while some crossings
and culverts are allowed they still need to be designed so that they do not
confine the channel or flood plain.
Exhibit 4
No change
10
11
18.45.110.C.d
18.45.180.4.f
d. Stream bed biofiltration to
Ion Manea requested to replace "system equivalent to ... and better than..."
with "system equivalent to the original stream"
Exhibit 4
Make changes noted in red
channel and systems equivalent or
prej €5s) aad better than in the original stream );
4.The Hearing Examiner, in granting approval of the reasonable use exception, must determine that:
a.There is no feasible on -site alternative to the proposed activities, including reduction in size or density,
modifications of setbacks, buffers or other land use restrictions or requirements, phasing of project
implementation, change in timing of activities, revision of road and lot layout, and/or related site planning that
would allow a reasonable economic use with fewer adverse impacts to the critical area
b. As a result of the proposed development there will be no unreasonable threat to the public health, safety or
welfare on or off the development proposal site. c.
Alterations permitted shall be the minimum necessary to allow for reasonable use of the property.
d.The proposed development is compatible in design, scale and use with other development with similar site
constraints in the immediate vicinity of the subject property if such similar sites exist.
e.Disturbance of critical areas and their buffers has been minimized to the greatest extent possible.
f. All unavoidable impacts are fully mitigated.
( g. thru i.)
Ion Manea requested to not include the provision " All unavoidable impacts
are fully mitigated" as requiring full mitigation of impacts will exclude the
use of reasonable use exception permitting alternative. Staff notes that
mitigation of impacts is required, there are options for offsite mitigation or
in -lieu fee programs. Additionally, the reasonable use process will take into
account the scale of the project proposed and the extent of mitigation
required will need to meet nexus and proportionality test.
Exhibit 4
No change.
12
18.45.195.D.3.b.
b. The amount of the penalty shall be $1,000 per tree or up to the marketable value of each tree removed or
damaged as determined by an ISA certified arborist. The Director may elect not to seek penalties or may reduce
the penalties if he/she determines the circumstances do not warrant imposition of any or all of the civil penalties.
Ion Manea requested that instead of a minimum penalty of $1000 per tree
regardless of the tree size and marketable value of each tree, the penality
should be "up to the markeable value of the tree established by a certified
professional." Staff notes that the existing proposed language address this
concerns as it states, "$1000 per tree or up to the marketable value of each
tree as determined by an ISA certified arborist".
Exhibit 4
No change as existing language
addresses this concern.
13
18.45.90.D.d
Wetland and Buffer Mitigation Location: d.Regional goals for flood storage, flood conveyance, habitat or other
wetland functions have been established and strongly justify location of mitigation at another site, and where off-
WRIA 9 submitted comments on Shoreline and Critical Areas Code update.
Majority of the comments were related to Shoreline code update. One
recommendation that was related to Critical Areas Code was to reference
2005 WRIA 9 Salmon Habitat Plan inlcuding language that accomodates
addendums and updates to the Plan. The City's Public Works staff also
recommended that WRIA 9 Salmon Habitat Plan should be referenced for
selection of offsite mitigation locations.
Exhibit 5
Make changes noted in red.
site mit ation is demonstrated to provide a greater ecological benefit to the watershed. Refer to 2005 WRIA 9
Salmon Habitat Plan or as amended, for potential offsite mitigation locations.
36
Row
Number
Section
Requested Change
Comment Summary/Staff Discussion
Source
Staff Recommendation
14
18.45.70.A.6.
Outright Permitted Activities in Critical Area or its buffer 6. Voluntary native revegetation and/or removal of
invasive species that does not include use of heavy equipment or herbreide. The use of herbicide by a licensed
Ben Peterson, King County Noxious Weed Control Program submitted
comments stating that the use of herbicide by a licensed contractor (with
certification as needed from the WA Dept. of Ecology and the WA Dept. of
Agriculture) is often the least disruptive method that can be used in critical
areas (such as steep slopes, shoreline areas and wildlife habitats). Herbicide
application is quiet, does not disturb the soil (which could cause erosion and
expose more weed seeds to growth), and can be targeted at specific plants.
Planning Commission also requested herbicide issues be addressed. Staff
has proposed revised language to address comments.
Exhibit 6,
Planning
Commission
Make changes noted in red
contractor with certification as needed from the WA Dept. of Ecology and the WA Dept. of Agriculture is permitted
but requires notification prior to application to the city and shall comply with TMC 18.45.158.E.3
15
18.45.158.B.3
B. Vegetation Retention and Replacement 3.Invasive vegetation (blackberry, ivy, laurel, etc.) may be removed
from a critical area or its buffer except steep slopes without a permit if removal does not utilize heavy equipment
or hcrbicide.The use of herbicide by a licensed contractor with certifications as needed from the WA Dept. of
Same as above
Exhibit 6,
Planning
Commission
Make changes noted in red
Ecology and the WA Dept. of Agriculture is permitted but requires notification prior to application to the city and
shall comply with TMC 18.45.158.E.3. Invasive vegetation removal on steep slopes requires prior City Approval
16
18.45.158.D.3
D. Plant Material Standards 3. Removal of invasive species shall be done by hand or with hand-held power tools.
The use of herbicide by a licensed contractor with certifications as needed from the WA Dept. of Ecology and the
Same as above
Exhibit 6,
Planning
Commission
Make changes noted in red
WA Dept, of Agriculture is permitted but requires notification prior to application to the city and shall comply with
TMC 18.45.158.E.3. Where not feasible and mechanized equipment is needed, the applicant must obtain a Type 2
permit prior to work being conducted. Removal of invasive vegetation must be conducted so that the slope
stability, if applicable, will be maintained and native vegetation is protected. A plan must be submitted indicating
how the work will be done and what erosion control and tree protection features will be utilized. Federal and
State permits may be required for vegetation removal with mechanized equipment.
37
Row
Number
Section
Requested Change
Comment Summary/Staff Discussion
Source
Staff Recommendation
17
18.45.158.E
E. Vegetation Management in Critical Areas The requirements of this section apply to all existing and new
development within critical areas.
1.Trees and shrubs may only be pruned for safety, to maintain access corridors and trails by pruning up or on the
sides of trees, to maintain clearance for utility lines, and/or for improving critical area ecological function. No more
than 25% may be pruned from a tree within a 36 month period without prior City review. This type of pruning is
exempt from any permit requirements.
2.Plant debris from removal of invasive plants or pruning shall be removed from the site and disposed of properly
unless on site storage is approved by the Director. Per King County Noxious Weed Control Program guidelines,
Ben Peterson, King County Noxious Weed Control Program stated that per
KCNWP guidelines, Regulated Noxious Weeds need to be disposed of in the
landfill/trash and non -regulated noxious weeds can be disposed of in green
waste or composted on site. Staff has proposed language.
Exhibit 6
Make changes noted in red
Regulated Noxious Weeds need to be disposed of in the landfill/trash and non -regulated noxious weeds can he
diosed of in Green waste or composted on site.
3.Use of pesticides.
a. Pesticides (including herbicides, insecticides, and fungicides) shall not be used in the critical area or its buffer
except where:
(1) Alternatives such as manual removal, biological control, and cultural control are not feasible given the size of
the infestation, site characteristics, or the characteristics of the invasive plant species; and herbicide is determined
to be least ecologically impactful;
(2) The use of pesticides has been approved by the City through a comprehensive vegetation, or pest management
and monitoring plan, or a King County Noxious Weed Control Program Best Management Practices document;
(3) The pesticide is applied in accordance with state regulations;
(4) The proposed herbicide is approved for aquatic use by the U.S. Environmental Protection Agency; and
(5) The use of pesticides in the critical area is approved by the City and the applicant presents a copy of the
Aquatic Pesticide Permit issued by the Department of Ecology or Washington Department of Agriculture, if
required.
b. Self-contained rodent bait boxes designed to prevent access by other animals are allowed.
c. Sports fields, parks, golf courses and other outdoor recreational uses that involve maintenance of extensive
areas of turf shall implement an integrated turf management program or integrated pest management plan
designed to ensure that water quality in the Critical Area is not adversely impacted.
18
Nancy Rogers representing Segale Properties submitted follow up email to
her earlier comments (Exhibit 2) requesting vesting languge to added to
Shoreline Code
Exhibit 7
No changes, this item was addressed
as part of Shoreline Code update
meeting on April 25, 2019
19
18.06.720
"Critical Sensitive areas" means wetlands, watercourses, areas of potential geologic instability (other than Class I
areas), abandoned coal mine areas, and fish and wildlife habitat conservation areas, and special hazard flood
areas.
Add definition for Critical Areas. Amendments to the definitions section
included. See attached.
Planning
Commission
Staff recommends changes to
Definitions Chapter. See attached
(Attachment C)
20
16.52.030(32)
"Special Flood Hazard Area" means the land in the flood plain subject to a 1% or greater chance of flooding in any
given year. It is also referred to as the 100-year flood elevation or the base flood elevation. These areas are
designated on Flood Insurance Rate Maps (FIRMS) using the letters A or V. Special flood hazard areas include flood -
prone areas designated by the City
• 18.45.30 A (6) What is a "Special Hazard Flood Area(s) TMC 16.52.030
defines it. Reference has been added to TMC 16.52.
Planning
Commission
No change needed.
21
Areas of seismic instability are defined and regulated through the Washington State Building Code. See maps fer
•g _f "'
• 18.45.30 B — references a map for designated areas of seismic instability —
where is the map? The reference is removed. All the critical areas maps
shall be available online. TMC 18.45.30G addresses location of Critical Area
maps
Planning
Commission
Make changes noted in red.
e* y
38
Row
Number
Section
Requested Change
Comment Summary/Staff Discussion
Source
Staff Recommendation
22
23
24
18.45.30G
18.45.40.B.12
18.45.40.D.1
A. CRITICAL AREAS MAPS AND INVENTORIES 1. The distribution of many critical areas and potential critical
areas in Tukwila is displayed on the Critical Areas Maps, on file with the Department of Community Development
(DCD). These maps are based on site assessment of current conditions and review of the best available scientific
data and are hereby adopted by reference. Not all critical areas are shown on the map. Thus it is the responsibility
of property owners and applicants to verify actual presence or absence of a critical area or critical area buffer
based on the definitions in this code. Applicant is also responsible for delineation and categorization of potential
wetland based on methodology required under TMC 18.45.80 and verifying that watercourse typing and location
is consistent with TMC 18.45.100.
2. Studies, preliminary inventories and ratings of potential critical areas are on file with the Department of
Community Development. 3. As
new environmental information related to critical areas becomes available, the Director is hereby designated to
periodically add, remove or alter new information to the Critical Areas Maps. Removal of any information from the
critical area maps is a Type 1 decision
B12 Wetland and Watercourse special studies are valid for five years following the date of the study, unless
otherwise determined by the Director.
The Director may limit the required geographic area of the critical area study as appropriate if the applicant, with
assistance from the City, cannot obtain permission to access properties adjacent to the project area.
• 18.45.30 G —this section got reworked and puts all of the onus on the
applicant. The struck language was more appropriate ie. "Director may
require..." Given the
city's inventory maps are not based on actual delineation, the applicant is
responsible for submitting reports as part of their development permits.
Planning
Commission
No change.
• 18.45.40 B 12. Studies are valid for 5 years — then what is required and
why? The existing
code did not have a time limit on how long the studies were valid. Given the
site conditions and hydrology can change over time the studies need to be
updated after onsite assessment.
Planning
Commission
No change
• 18.45.40 D 1. The second sentence doesn't read very well about "access
permission" This
language is to provide wiaver in case access to adjacent property is not
available.
Planning
Commission
No change
25
18.45.40.E
REVIEW OF STUDIES — The Department of Community Development will review and verify the information
submitted in the critical area study to confirm the nature and type of the critical area. Public Works Department
shall seek a peer review of the geotechnical report on Class 3 and 4 slopes; and peer review on Class 2 slopes may
be required at the discretion of the Public Works Director. Peer review of the geotechnical reports shall be at the
expense of the applicants. For all other critical areas and at the discretion of the Director, critical area studies may
undergo peer review, at the expense of the applicant.
• 18.45.40 E. Can DCD Director Approve? Yes, the
Director can approve. Specific language added for geotechnical peer review
requirement.
Planning
Commission
No change
26
1845.80.B
Wetlands shall be designated in accordance with the Washington State Wetlands Rating System for Western
Washington, (Washington State Department of Ecology,2014, Publication # 14-06-029); or as otherwise amended
by Ecology as Category I, II, III, or IV as listedbelowthe
• 18.45.80 B. first paragraph last three words "as listed below" reference the
table 18.45.080-1 Comment noted,
phrase "as listed below" removed.
Planning
Commission
Make change noted in red.
27
18.45.158.C.8
8. Any branches or limbs that are outside of the CRZ and might be damaged by machinery shall be pruned prior to construction
by Qualified Tree Professional. No knits the direct
• 18.45.158 C. 8. "No construction personnel shall prune " eliminate this
wording and just say the removal must be done or overseen by a qualified
professional. Staff is proposing the change.
Planning
Commission
Make change noted in red.
a construction ntnel shalt prune affected except ender supervision of a
Qualified-Tree-Professonal.
28
18.45.158.D.3
D. Plant Material Standards 3. Removal of invasive species shall be done by hand or with hand-held power tools.
The use of herbicide by a licensed contractor with certifications as needed from the WA Dept. of Ecology and the
WA Dept. of Agriculture is permitted but requires notification prior to application to the city and shall comply with
TMC 18.45.158.E.3. Where not feasible and mechanized equipment is needed, the applicant must obtain a Type 2
permit prior to work being conducted. Removal of invasive vegetation must be conducted so that the slope
stability, if applicable, will be maintained and native vegetation is protected. A plan must be submitted indicating
how the work will be done and what erosion control and tree protection features will be utilized. Federal and
State permits may be required for vegetation removal with mechanized equipment.
• 18.45.158 D. 3. Remove the word "permission". They must get a permit.
Type 2 permit is referenced
Planning
Commission
No change needed.
39
Row
Number
Section
Requested Change
Comment Summary/Staff Discussion
Source
Staff Recommendation
29
30
18.45.158.D.8
18.45.090.C.2.c
8. Smaller plant sizes (generally one gallon, bareroot, plugs, or stakes, depending on plant species) are preferred
for buffer plantings. Willow stakes must be at least 1/2-inch in diameter. For existing developed areas refer to
landscaping chapter TMC 18.52 for plant sizes in required landscape areas.
Square feet Acragerequirements for creation, re- establishment, rehabilitation or enhancement and for
• 18.45.158 D. 8. It says smaller plant sizes are preferred, should they be
required? The
planting plan is based on case by case. Smaller plants are preferred but in
some cases larger plants may be more pretinent. Therefore it is not a
requirement but preference.
Planning
Commission
No change needed.
Replace the word "acreage" with square feet.
Planning
Commission
proposed wetland classes are met.
31
Various sections of the code were updated for clarity. These sections are
highlighted in the attached underline/strikeout version of the code.
City Attorney,
Staff
Changes incorporated in the
underline/strikeout version and
highlighted.
32
Upon further review of the Tree Chapter, Landscape Code, Critical Areas
Code and Shoreline Code it is not explicitly stated which section applies
when areas overlap. Additionally, it is becoming difficult to implement. We
have included a flow chart to help explain the legislative intent and to help
determine which section applies. However staff is suggesting adding an
applicability section to help clarify which code section applies to residential
properties vs non-residential vs undeveloped properties. Staff is also
seeking policy direction to see if different sections for the four chapters
should be looked at for consistency.
Staff
Seeking policy direction from the
Planning Commission. See attached
flow chart (Attachment D)
40
Chapter 18.06
DEFINITIONS
Sections:
18.06.017 Adaptive Management
18.06.018 Adjacent
18.06.069 Best Available Science
18.06.160 Compensatory Mitigation
18.06.196 Daylighting
18.06.264 Engineer, Geotechnical
18.06.266 Engineer, Professional
18.06.268 Engineering, Geotechnical
18.06.710 Critical Sensitive Area Buffer
18.06.715 Critical Sens444veArea Regulated Activities
18.06.720 Critical Sensitive Areas
18.06.725 Critical Sensitive Areas Ordinance
18.06.730 Critical Sensitive Area Tract or Easement
18.06.926 Constructed Wetlands or Watercourses, Constructed
18.06.928 Wetland, Emergent
18.06.930 Wetland, Forested
18.06.932 Wetland, Isolated
18.06.933 Wetland, Regulated
18.06.934 Wetland, Scrub -Shrub
18.06.017 Adaptive Management
"Adaptive management" means the use of scientific methods to evaluate how well
regulatory and non -regulatory actions protect a sensitivecritical area.
18.06.036 Alteration
"Alteration" means any human -induced change in an existing condition of a
sensitivecritical area or its buffer. Alterations include, but are not limited to, grading,
filling, channelizing, dredging, clearing of vegetation, construction, compaction,
excavation, or any other activity that changes the character of the sensitivecritical area.
18.06.069 Best Available Science
"Best Available Science" means that scientific information applicable to the
scnsitivecritical area prepared by appropriate local, state or federal agencies, a qualified
scientist or team of qualified scientists, which will be consistent with the criteria
established in WAC 365-195-900 through WAC 365-195-925. Characteristics of a valid
scientific process will be considered to determine whether information received during
the permit review process is reliable scientific information. A valid scientific process
includes some or all of the following characteristics:
1. Peer reviewed research or background information.
2. Study methods clearly stated.
3. Conclusions based on logical assumptions.
4. Quantitative analysis.
5. Proper context is established.
6. References are included that cite relevant, credible literature and other
pertinent information.
41
catastrophic events ithin an ar 1 hich no long
here it did not formerly exist;
dcgradcd wetland or its buffcr so that thc functions it provides arc of a higher q l'ty.
drainage ditches, grad lined swalcs, canals, detention facilities, wastcwatcr tr
watercourses created through compensatory mitigation.
0
b
{Ord. 1758 §1(part), 1995
18.06.285 Essential Street, Road, or Right -of -Way
"Essential street, road, or right-of-way or utility" means a
system, street, road or right-of-way where no feasible alternative location exists based
on an analysis of technology and system efficiency.
18.06.287 Essential Utility
"Essential utility" means a utility facility or utility system, where no feasible alternative
location exists based on an analysis of technology and system efficiency.
18.06.335 Forested Wetland
IIr 1 1 Itt
0
covered by trees greater than 20 fcct in hcigh .
18.06.360 Ccotcchnical Engin cr
"Ceotechnical engineer" means a practicir+g, geotechnical/ciA, il engineer licensed as a
professional employment as a gcotcchnical engineer with experience in landslide
evaluation.
18.06.581 Mitigation
"Mitigation" means replacing project induced wetland sensitivecritical area and
buffer losses or impacts, and includes but is not limited to the following:
1. Restoration: Actions performed to reestablish wetland sensitivecritical area and
its buffer functional characteristics and processes which have been lost by alterations,
42
activities or catastrophic events within an area which no longer meets the definition of a
wetland scnsitivccritical area;
2. Creation: Actions performed to intentionally establish a wetland
scnsitivccritical area and its buffer at a site where it did not formerly exist;
3. Enhancement: Actions performed to improve the condition of an existing
degraded wetland scnsitivccritical area or its buffer so that the functions it provides are
of higher quality.
18.06.710 Critical Sensitive Area Buffer
"Critical Sensitive area buffer" means an area lying adjacent to but outside a
scnsitivccritical area as defined by this Title, whose function is to protect
critical areas from the potential adverse impacts of development, land use, or other
activities. A wetland or watercourse scnsitivccritical area buffer also provides critical
habitat value, bank stabilization, and or water overflow area functions.
18.06.715 Critical Sensitive Area Regulated Activities
"Critical Sensitive area regulated activities" means any of the following activities
which that are directly undertaken or originate in a regulated wetland or watercourse
or their buffers:
1. Removal, excavation, grading or dredging of soil, sand, gravel, minerals,
organic matter or material of any kind;
2. Dumping, discharging or filling with any material;
3. Draining, flooding or disturbing the water level or water table;
4. Driving of pilings;
5. Placing of obstructions;
6. Construction, reconstruction, demolition or expansion of any structure;
7. Destruction or alteration of wetlands, watercourses or their buffers through
clearing, harvesting, shading, intentional burning or planting of vegetation that would
alter the character of a regulated wetland, watercourse or buffer, provided that these
activities are not part of a forest practice governed under RCW 76.09 and its rules; or
8. Activities that result in a significant change to the water sources of wetlands
or watercourses. These alterations include a significant change in water temperature;
physical or chemical characteristics, including quantity; and the introduction of pollu-
tants.
18.06.720 Critical Sensitive Areas
"Critical Sensitive areas" means wetlands, watercourses, areas of potential
geologic instability (other than Class I areas), abandoned coal mine areas, and fish and
wildlife habitat conservation areas, and special hazard flood areas.
(Ord. 1758 §1(part), 18.06.725 Critical Sensitive Areas Ordinance
"Critical Sensitive Areas Ordinance" means the Environmentally Critical Sensitive
Areas Oe4sh4etchapter of this title or as amended hereafter which establishes
standards for land development on lots with scnsitivccritical areas (e.g. steep slopes,
wetlands, watercourses, etc.).
18.06.730 Critical Sensitive Area Tract or Easement
"Critical Sensitive area tract or easement" means a tract or portion of a parcel
which that is created to protect the scnsitivccritical area and its buffer, whose main-
tenance is assured, and which is recorded on all documents of title of record for all
affected lots and subsequent owners.
43
"Tree" means any self supporting woody plant, which at maturity is usually 20
characterized by one main trunk, with a
"Tree' cl aring permit" means a permit issued by thc Director authorizing tree
clearing actik itics, pursuant to the general permit provisions of this title.
18.06.922 Wetlands
"Wetlands" means those areas that are inundated or saturated by groundwater or
surface water at a frequency and duration sufficient to support, and that under normal
circumstances do support, a prevalence of vegetation typically adapted for life in
saturated soil conditions. Wetlands generally include bogs, swamps, marshes, ponds,
lakes and similar areas. Wetlands do not include those artificial wetlands intentionally
created from non -wetland sites, including but not limited to irrigation and drainage
ditches, grass -lined swales, canals, detention facilities, wastewater treatment facilities,
farm ponds, landscape amenities or those wetlands created after July 1, 1990 that were
unintentionally created as a result of the construction of a road, street or highway.
However, those artificial wetlands intentionally created from nonwetland areas to
mitigate conversion of wetlands as permitted by the City shall be considered wetlands.
18.06.924 Wetland Edge
"Wetland edge" means the delineated boundary of a wetland performed in
accordance with approved federal wetland delineation manual and current applicable
regional supplements.
18.06.932 Wetland, Isolated
"Isolated wetlands" means those wetlands which that:
Are not hydrologically connected tooutsidc of and not contiguous to any 100 ear
floodplain of a lake, river or stream, in accordance with current State and federal
regulations; and have no contiguous hydric soil and hydrophytic vegetation between
18.06.933 Wetlands, Regulated
"Regulated wetlands" means ponds or lakes 30 20 acres or less and those lands
subject to the "wetland" definition contained in this chapter. Wetlands 1,000 sq. ft. and
less that do not meet any of the criteria of TMC 18.45.080B arc not regulated.
44
�-` n�"nw;U�/«� �-�^��� Regulations
..~..~.~.~~~° .~~~~~
Is the tree in the
Shoreline?
yes
\ /
Shoreline Tree
' Removal &
VegetationC|eahn
Permit
Refer VoTMC
18.445hore|ine
Overlay
Basic Points:
'f\smuch native vegetation
aupossible in0oberetained
--if site is not undergoing
development trees may not
be removed
-|yatree is^kazardoua^.
anarboristreport can be
required before decision
-ovendead trees must
remain
-iftrees are removed, refer
0oTree Replacement
Requirements table in TMC
18.44.080
--all vegetation planted must
be native
|sthe tree in an
environmentally
sensitive area?
yes
~
Tree Permit
|
Refer 0nTMC
l8.547iee
Regulations
except for Table x
`
Basic Points:
-Asmuch native vegetation
aopossible is0oboretained
-SeeTMCI8.54.O8OTable
Bfor replacement standards,
based onthe canopy
coverage ofthose that were
removed
--hazardous/extreme risk
trees may boremoved in
advance o[apermit, but
replacement standards
still apply
-nrp|acrmcmtrees can
uechosen from Tukwi|a'n
Approved Tree List
no
|sthe tree nna
property with a
single family
home oren
undeveloped
site?
yes
\ /
Refer toTMC
lU.54Tee
Regulations
Basic Points:
-Dependingonsize,
applicants can remove 1-4
trees onproperty ma
35'monthperiod See TMC
18,54.040 Table A for
removal allowance, If these
limits are exceeded,
see TMCl8.54.O80Table D
for replacement standards
based on the canopy
coverage of those that were
removed
--hazardous/extreme risk
trees may beremoved in
advance ofapermit, but
replacement standards
still apply
-mop|acomonttrees can be
chosen from Tuhwi|a'o
Approved Tree List
|sthe tree nn
property that is
commercial,
industrial, or
yes
�
Tree Removal &
Landscape Mod
Permit
Refer tnTMC
8.52Lundscape
Requirements
Basic Points:
-Largeand medium trees
are required where there io
sufficient planting area
-Landscapingmust meet the
Type |.U.orIII screening
requirements depending on
#hopmporty/zoning
-|ftrees are 0oberemoved,
the applicant must show that
they still meet the
landscaping requirements for
that area, and replace trees if
necessary
--Replacement trees can
bochosen from Tvwwi|a'e
Approved Tree List
_
�
46
Page 1 of 42
Sections:
18.45.010 Purpose
18.45.020 Best Available Science
18.45.030 Sensitive Critical Area Applicability, Maps and Inventories
18.45.040 t+ Critical Areas Special Studies
18.45.050 Interpretation
18.45.060 Procedures
18.45.070 ' Critical Area Permitted Uses
18.45.080 Wetlands Designations, Ratings and Buffers
18.45.090 Wetland Alterations and Mitigation
18.45.100 Watercourse Designations, Ratings and Buffers
18.45.110 Watercourse Alterations and Mitigation
18.45.120 Areas of Potential Geologic Instability Designations, Ratings and Buffers
18.45.130 Areas of Potential Geologic Instability Uses, Exemptions, Alterations and Mitigation
18.45.140 Abandoned Mine Areas
18.45.150 Fish and Wildlife Habitat Conservation Areas —
Designation, Mapping, Uses and Standards
18.45.155 Special Hazard Flood Areas
18.45.158 Vegetation Protection and Management
18.45.160 SensitivcCritical Area Master Plan Overlay
18.45.170 SensitiveCritical Areas Tracts and Easements
18.45.180 Exceptions
18.45.190 Appeals
18.45.195 Enforcement and Penalties
18.45.200 Recording Required
18.45.210 Assurance Device
18.45.220 Assessment Relief
18.45.10 Purpose
A. The purpose of TMC Chapter 18.45 is to protect the environment, human life and propertyl; to designate and
classify ecologically sensitivocritical areas including but not limited tosuch as regulated wetlands and watercourses
and geologically hazardous areas and to protect these critical areas and their functions while also allowing for
reasonable use of public and private property. These regulations are prepared to comply with the Growth Management
Act, RCW 36.70A, to apply best available science according to WAC 365-195-900 through 925 and to protect critical
areas as defined by WAC 365-190-080.
B. Standards are hereby established to meet the following goals of protecting environmentally s+' critical
areas:
1. Minimize developmental impacts on the natural functions of these areas.
2. Protect quantity and quality of water resources.
3. Minimize turbidity and pollution of wetlands and fish- bearing waters and maintain wildlife habitat.
4. Prevent erosion and the loss of slope and soil stability caused by the removal of trees, shrubs, and root
systems of vegetative cover.
5. Protect the public against avoidable losses, public emergency rescue and relief operations cost, and
subsidy cost of public mitigation from landslide, subsidence, erosion and flooding.
6. Protect the community's aesthetic resources and
47
Page 2 of 42
distinctive features of natural lands and wooded hillsides.
7. Balance the private rights of individual property owners with the preservation of environmentally
sensitivecritical areas.
8. Prevent the loss of wetland and watercourse function and acreage, and strive fora gain over present
conditions.
9. Give special consideration to conservation or protection measures necessary to protect or enhance
ana- dromous fisheries.
10. Incorporate the use of best available science in the regulation and protection of sensitivecritical areas
as required by the State Growth Management Act, according to WAC 365-195-900 through 365-195-925 and WAC
365-190-080.
(Ord. 2301 §1(part), 2010)
18.45.20 Best Available Science
A. Policies, regulations and decisions concerning critical areas shall rely on best available science to
protect the functions of these areas and must give special consideration to conservation or protection measures
necessary to preserve or enhance anadromous fish and their habitats.
B. Nonscientific information may supplement scientific information, but is not an adequate substitution
for valid and available scientific information.
C. Incomplete or unavailable scientific information leading to uncertainty for permitting sensitivecritical area
impacts may require application of effective adaptive management on a case by case basis. Adaptive management
relies on scientific methods to evaluate how well regulatory or non -regulatory actions protect critical areas
or replace their functions.
(Ord. 2301 §1 (part), 2010)
18.45.30 Critical Area Applicability, Maps, and Inventories
18.45 APPLICABILITY— The provisions of TMC Chapter 18.45 shall apply to all land uses and all development
activities in a sensitivecritical area or a sensitivecritical area buffer as defined in the "Definitions" chapter of this title.
The provisions of TMC Chapter apply whether or not a permit or authorization is required within the City of Tukwila.
No person, company, agency, or applicant shall alter a sensitivecritical area or buffer except as consistent with the
purposes and requirements of TMC Chapter 18.45. The following are sensitivecritical areas regulated by TMC
Chapter 18.45:
1. Coal Mine Hazard Areas ;
2. Areas of potential geologic instability: Class 2, 3, 4 areas (as defined in the Definitions chapter of
this title and TMC 18.45.120.A);
3. Wetlands;
4. Watercourses;
5. Fish and Wildlife Habitat Conservation Areas; and
5=6. Special Hazard Flood Areas. (See TMC 16.52 for additional regulations)
A- B.The Growth Management Act also identifies
as critical areas.
areas of seismic instability
Areas of
seismic instability are defined and regulated through the Washington State Building Code. See maps for designated
ar as of seismic instability.
sensitivecritical area land, water or vegetation or to construct or alter any structure or improvement in, over, or on
a sensitivecritical area or its buffer, without first ensuring compliance with the requirements of TMC Chapter 18.15.
3. Approval of a permit or development proposal pursuant to the provisions of TMC Chapter 18.15 does
Page 3 of 42
&J}.|Othe event Of8conflict between Uh|SVVhepTNC Chapter 18.45 and any other |8vVS. [8Ou|8tiOOS.
ordinances or restrictive C0v8n8ntS, the provision which imposes greater restrictions Orhigher standards
upon the development or use of land than other laws, ordinances or restrictive covenants, the provisions of TMC
Chapter 1O.45shall prevail.
CRITICAL AREAS MAPS AND INVENTORIES
1 The distribution of many sensitivccritical areas and potential critical areas in Tukwila is displayed on the
Sensitive Critical Areas Maps, on file with the Department of Community Development (DCD). These
maps are based Onsite assessment Ofcurrent conditions and review Ufthe best available scientific data
and are hereby adopted by reference. Not all snnsihvnar anriUna| areas are shown on the map, Thus
it is the responsibility ofproperty owners and applicant's responsibility to verify actual presence or
absence Vfacritical area 0rcritical area buffer based 0nthe definitions inthis code. Applicant isalso
responsible for delineation and C809qOriz8tiVO of potential wetland based OO 08thUdO|Vqy required
und8[TK8C 18.45.80 and verifyinO that watercourse ty0iDq and |OC@U0n is consistent with TK8C
18,45.100.
2. GtudimS, preliminary inventories and ratings Ofpotential sensitive o/ aohtima| areas are nnfile with the
Department OfCommunity Development.
3. Annew environmental information related 0nsensitive ur nchdoo|areas becomes available, the Director
is hereby designated 03 periodically add new infOnn8UOn k}the Sensitive AreaCri1iCa|Are8S Maps.
Removal 0fany information from the :cnsiUvnomacridca|area maps i8aType 1 decision.
4. RegaFdless of whetheF a sensitive area is shown eR the sensitive areas map, the aGtHal pFesenGe GF
absenGe of the features defined 'R the eode as sensitive aFeas shall geverR. The D'reGtA'
the applicant to submit technical information to indicate whether -sensitive areas actually exist on or
5� _AJ| nevisionS, updates and reprinting of -sensitive areacritical areas mops, inventories, ratings and
buffers shall conform V3TMCChapter 18/45.
KJnt 230/§1(panU, 2010)
18.45.40 Sensitive Critical Areas Special Studies
A. Application Required. An applicant for 8 development p0pOG8| within 8 V8rc9| that may include
8sensitive or critical area and/or its buffer shall submit those studies 8Srequired bythe City and specified
below 1Oadequately identify and evaluate the sensitive or ooridCa|area and its buffers.
1. A required sensitive aroacritical area study shall be prepared by a person with experience and training
in the scientific discipline appropriate for the relevant sensitive Jr OcridCG| area as outlined below, in 8CD0[dGOSe
with VVAC 305'195'005(4). AqV8|ifi8d p0f8SGiOn8| must have obtained 3 B.S. Or B.A. Orequivalent degree in
ecology O[related science, engineering, environmental studies, fisheries, gSot8ChOiC8|O[related field, and two years
ofrelated work experience.
8. AquG|ifi8d professional for Fish and Wildlife Habitat C0OSSm8hOO A[8GS must have 8 degree in
ecology or related sciences and professional experience related 03the subject species.
b. Aqualified professional for wetland sensitive aneaCridoa|area studies must be3certified
Professional Wetland Scientist or a non certified Professional Wetland Scientist with 8tleast two years Offull-time
work experience as a wetlands professional, including delineating wetlands using the state orapproved federal
manual and applicable reOiOna|supplements, preparing wetland reports, conducting functional assessments, and
developing and implementing mitigation plans.
C. A qualified professional for 8 gRO|OgiC8| hazard study must be a professional geO08ShniC8|
engineer as defined in the D8fiOibOOS chapter of this dU8' |iC8OS8d in the state Of VY8ShiOgtOO.
d. A qualified professional for w808nCOUnS8S and frequently flooded areas means 3 hyd0|0giS1,
geologis(, fisheries biO|Oqist. engineer Orother scientist with 8xp8[i8OC8 in preparing w8t8nCOunS8 8SGHS808DtS.
2. The sensitive +*neaCridC8| area study shall use scientifically valid methods and studies in the analysis
Ufsensitive amoo[idc8|area data and shall use field reconnaissance and reference the source Ofscience used. The
-sensitive eR>eCriUoo|area study shall evaluate the proposal and all probable impacts tUsensitive an}onribC8|areas,
inaccordance with the provisions ofT&8CChapter 18.45.
49
Page 4 of 42
B. Wetland and Watercourse nsitive AreaCritical Area Studies. The sensitive areacritical
area study shall contain the following information, as applicable:
1. The name and contact information of the applicant, a description of the proposal, and identification
of the permit requested;
2. A copy of the site plan for the development proposal showing: sensitive areacritical areas and buffers
and the development proposal with dimensions, clearing limits, proposed storm water management plan, and
mitigation plan for impacts due to drainage alterations;
3. The dates, names and qualifications of the persons preparing the study and documentation of any
fieldwork performed on the site;
4. Identification and characterization of all sensitive ar acritical areas, water bodies, and buffers on or
adjacent to the proposed project
area or potentially impacted by the proposed project as described in the following sections:
a. Characterization of wetlands must include:
(1) A wetland delineation report that includes methods used, field indicators evaluated and the
results. Wetland delineation must be performed in accordance with approved federal wetland delineation manual and
current applicable regional supplements. Field data forms are to be included in the report. Data collection points
are to be shown on the site plan with their corresponding numbers indicated. After the City of Tukwila confirms the
boundaries, they are to be professionally surveyed to the nearest square foot and the site plan modified as necessary
to incorporate the survey data. Exact wetland acreage will be calculated after the boundaries have been surveyed.
Applicant must submit electronic survey data in Autocad, GIS or similar format at the time of as -built submittal.
(2) Cowardin (Classification of Wetlands and Deepwater Habitats of the U.S. — U.S. Department
of Interior) classification of the wetland(s).
(3) Hydrogeomorphic classification of the wetland(s).
(4) Hydroperiod.
(5) Brief landscape assessment of the wetland (identify hydrologic basin/sub-basin; inlets,
outlets; surrounding land use; habitat quality and connectivity; ultimate point of discharge; presence of culverts
or other constraints to flow; relationship to other wetlands/watercourses adjacent to or potentially impacted by the
proposed project).
(6) Description of buffer size per this chapter, conditions (topographic considerations, existing
vegetation types and density, habitat features, watercourse edges, presence of invasive species, etc.) and
functions.
(7) Functional aAssessment. For proposed wetland filling or proposed projects that will impact
buffers the Washington Wetland Classification System (2014 or most current) shall be used as a functional
assessment.
(8) Classification of the wetland under
b. Characterization of the watercourses on site,. or adjacent to, areas or potentially impacted by the
proposed project to the site must include:
(1) Description of: flow regime, physical characteristics of streambed, banks, dimensions and
bank -full width, stream gradient, stream and buffer vegetation conditions, habitat conditions, and existing
modifications.
(2) Brief landscape assessment of the watercourse (identify hydrologic basin/sub-basin, and
contributing basin area acreage, outlets, surrounding land use, habitat quality and connectivity, ultimate point of
discharge, presence of culverts or other constraints to flow, presence of man-made or natural barriers to fish
passage, relationship to wetlands or other watercourses adjacent to or potentially impacted by the proposed project,
flow regime).
(3) Classification of the watercourse under Tukwila's rating system.
(4) Description of buffer size per this chapter, conditions (topographic considerations, existing
Page 5 of 42
vegetation types
and density, habitat features, watercourse edges, presence of invasive species, etc.) and functions.
(5) Description of habitat conditions, wildlife/fish use of the watercourse, including sensitive,
threatened or endangered species.
c. Citation of any literature or other resources utilized in preparation of the report.
5. A statement specifying the accuracy of the study and assumptions used in the study.
6. Determination of the degree of hazard and risk from the proposal both on the site and on adjacent
properties.
7. An assessment of the probable cumulative impacts to sensitive arcacritical areas, their buffers and
other properties resulting from the proposal.
8. A description of reasonable efforts made to apply mitigation sequencing to avoid, minimize and mitigate
impacts to sensitive arcacritical areas.
9. Plans for adequate mitigation to offset any impacts.
10. Recommendations for maintenance, short-term and long-term monitoring, contingency plans and
bonding measures.
11. Any technical information required by the Director to assist in determining compliance with this
ChapterTMC Chapter 18.45.
11.12. Wetland and Watercourse special studies are valid for five years following the date of the study,
unless otherwise determined by the Director.
C. GEOTECHNICAL REPORT-
1. A geotechnical report appropriate both to the site conditions and the proposed development shall be
required for development in Class 2, Class 3, Class 4 areas, and any areas identified as Coal Mine Hazard Areas,
unless waived pursuant to TMC Section 18.45.040 E.
2. Geotechnical reports for Class 2 areas shall include at a minimum a site evaluation review of available
information regarding the site and a surface reconnaissance of the site and adjacent areas potentially impacted by
the proposed project. Subsurface exploration of site conditions is at the discretion of the geotechnical consultant.
3. Geotechnical reports for Class 3, Class 4 and Coal Mine Hazard Areas shall include a site evaluation
review of available information about the site, a surface reconnaissance of the site and adjacent areas potentially
impacted by the proposed protect, a feasibility analysis for the use of infiltration on -site and a subsurface exploration
of soils and hydrology conditions. Detailed slope stability analysis shall be done if the geotechnical engineer
recommends it in Class 3 or Coal Mine Hazard Areas, and must be done in Class 4 areas.
4. Applicants shall retain a geotechnical engineer to prepare the reports and evaluations required in
this subsection. The geotechnical report and completed site evaluation checklist shall be prepared in accordance
with the generally accepted geotechnical practices, under the supervision of and signed and stamped by the
geotechnical engineer. The report shall be prepared in consultation with the Community Development and Public
Works Departments.
5. The opinions and recommendations contained in the report shall be supported by field observations
and, where appropriate or applicable, by literature review conducted by the geotechnical engineer which shall
include appropriate explorations, such as borings or test pits, and an analysis of soil characteristics conducted by
or under the supervision of the engineer in accordance with standards of the American Society of Testing and
Materials or other applicable standards. If the evaluation involves geologic evaluations or interpretations, the report
shall be reviewed and approved by a geotechnical engineer._
D. CRITICAL AREA STUDY - MODIFICATIONS TO REQUIREMENTS —
a-1.The Director may limit the required geographic area of the sensitive ar acritical area study as
appropriate if_;
tThe applicant, with assistance from the City, cannot obtain permission to access properties adjacent to the project
area; or,
b. The proposed activity will affect only a limited part of the site.
2.The Director may allow modifications to the required contents of the study where, in the judgment of a
51
Page 6 of 42
qualified professional, more Orless infnOD8d0n is required to adequately address the oobnh8| sensitive
efe_acritica|area impacts and required mitigation.
EWAIVER A waiver to the SeRsitive area study may be graRted by the DiFeGt9Fif the fbIlowiRg GeRditio%
have been met:
1� Ameticnd has been classifi^dcnd delineated, mthe Ordinary High Water Mark has been
deteFMiRed iR waterGeurses and GE)Rfirmed by the City withiR the last twe years, R aGGerdaRG8 With the reqUOMM8F)tS
ofthis chapter.
2. The donnifiooUon and |ooednn of wetland boundaries or OMVVM have been confirmed by the City, and
the pmpnnmd development or action will avoid all impacts to the nennidveanaa/s\.
3. There is nubs\anUo| evidence there will be no detrimental impact to the sensitive areas orbuffers,
and that the goo|n, purpo:cn, objectives and requirements of TK4C Chapter
18.15will befollowed.
FL.E. REVIEW OF STUDIES — The Department of Community Development will review and verifv the information
submitted iOthe sensitive ar acritical area study to verify the information, to confirm the nature and type of the
sensiUvear oCridC8|area, and ensure the study isconsistent with T[NCChapter 18A5. Public Works Department
shall seek a peer review ofthe Qoo0aohnioa|report nnClass Jand 4slopes; and peer review nnClass 2slopes may
be required at the discretion of the Public Works Director. Peer review of the qeotechnical reports shall be at the
expense Vfthe applicants. For all other critical areas and aAt the discretion 0fthe Director, con:i8vCoumCri1icG|area
studies may undergo peer review, 8tthe expense Ofthe applicant. (Ord230G§47,2812;Ord. 2301§/(pa¢),20i0
The provisions of TMG Chapter 18.45 shall be held to be mi i . Rents in their inteFpretatiep an
application and shall bnliberally construed huserve the purposes nfTNC 18A5.
and d'menswons of a'! sensffive areas and buffers on the ske shall be 'ndicated on the plans
waive item numbers 1.2.4and 5ofthe following if the size and complexity Ofthe project does not
WaFFaRt that step OR the PFE)Gedures and the f llowiRg are required unless the DireGtE)F graRts a waiver.
pursuant to TK4C Section 18.45.040E. Approval bvthe DepartmentnfeSensitive area alteration is
observe sensiUvearea oondihon:,
B. The applicant shall grant the City the right Ofcontinuous entry upon proper notice tOobserve critical area
conditions.
C. Sensitive areas study and g8n/oohnice/report:
Q. The applicant shall submit the relevant study 8S required inTN>CSection 21.O4.14Oand TK4CChapter
49.4
E. It is intended that sensitive areas studies and infOnn88On be utilized by applicants in preparation of
their proposals and therefore nhn|| be undertaken early in the design Stages Ofe project.
F. Planned residential development permit: Any new residential Subdivision ormultiple family residential
proposal that includes a wetland or watercourse Or its buffer on the site may apply for a planned
pnoidenUo| development permit and meet the requirements of the Planned Residential Development
District chapter Ofthis title.
G. Denial ofuse ordevelopment: Ause Vrdevelopment will be denied if the Director determines the
applicant cannot ensure that potential dangers and costs t0future inhabitants Ofthe devC|opment,
properties, and Tukwila are minimized and mitigated ho8nacceptable level,
Page 7 of 42
site.
i Construction monitoring: The specialistqualified professional(s) of record shall be/etainad k)monitor the
cite during construction.
J. On'si0o identification: The Director may require the boundary between a sensitive areauhUna!ama and
Oandc o/ metal sign mounted on a treated wood, concrete ormetal post. Sign -size will be determined at
affixed hothe post hvbolts and the wording shall boanfollows:
K. "Protection nfthis natural area isinyour care. Alteration, dumping ovdisturbance iaprohibited pursuant to
"
18/15.70 ritical Area Permitted .g- Activities
A. Outright PennittmdGoncr:| UsooAcdviUes. The uses set forth in this emUnu »eodon' including
subsections A. through O. and the The following general _uSoS. may be located within 8 sensitive area or
bu�er.activiUcsare outright penni�edgenem|1yuxomo �nmTK4CChap0ar 18.45. These activities are still subject
k)the provisions 0fTMCChapter 21.O4and Ofthe mitigation requirements OfTk8CChatter 18.45thiSchapter, if
applicable:
1. Maintenance and repair Of existing usoS—a+*d facilities provided no alteration or additional 8U
materials will bS
placed or heavy construction equipment used in the sensitive areacritical area or buffer.
�--Sit8exploration Urresearch that does not include use 0fheavy equipment Ornative vegetation
mmovaUNondostruodvaeducation and research.
3-.2]Passive recreation and open space.
43Maintenance and repair of essential 8heets, roads, rights -of -way, or ud|iheS, and placement,
maintenance, and nBp8irOf,Oe*fibe0pdCutilities within existing improved and paved road.
5A.Actions k)remedy the effects Ofemergencies that threaten the public health, safety O[welfare.
5. Maintenance activities Of existing landscaping and gardens in 3 Sef-si��anhtiu8| area buffer
including, but not |i0i1Sd' to mowing |8wOS' vv88diOg' ham8SUOg and n8p|aOUOg of garden C0pS and pruning and
planting of vegetation. The This provision does not apply to removal of established native trees and shrubs, or to the
is net xC8vaU0n, fi||inO, and construction of new landscaping features, such as concrete work, berms and
w3||S.
0. Voluntary native nnvoOetetinn and/or removal of invasive species that does not include use of heavy
equipment Orherbicide.
B. PERMITTED ACTIVITIES SUBJECT TO ADMINISTRATIVE REVIEW. The following uses may
be permitted only after administrative review and approval of a Type 2 Special Permission application by the Director:
1. K48iOt8O3OCS and [8p8i[ of existing uS8S and facilities where alteration O[additional fill materials will
be placed Orheavy construction equipment used inthe critical area Orbuffer.
2. New surface water discharges tO-sensitive oraChdCa|areas O[their buffers from detention facilities, pre -
settlement ponds Orother surface water management structures may be a||Ovved provided that the discharge meets
the clean water standards OfRCVY8O.4Oand VYAC173.20Oand 173.2O18Samended, and does not adversely affect
vvSi|GOd hydrology or watercourse flow
watercourse habitat and watercourse flow conditions relative to the existing rate. Water quality monitoring may be
required 8S8condition [fuse.
3. Construction nf9bioSw8|8Sand dispersion trenchesoutAa4s, are the only storm water facilities allowed in
wetland 0[watercourse buffers. Water quality monitoring may b8required 8S8condition Ofuse
4. EOh3OQO08Ot or other miUg8d0O including |8OdSC8piOg with O8UY8 p|8OCS that requires heavy
o0uiVment7.
53
Page 8 of 42
5. Construction ormaintenance nfEssential Utilities ifdesiqnodk-.
a. Essential utilities must be constructed to minimize, #r where possible avoid, disturbance of the
All construction must be designed to protect the area and its buffer againstS0SioO,
uncontrolled storm water, n8sthCUOn of groundwater 0Uv80Snt' S|id8S. 0d|uUOn, habitat disturbance,
any |OSs of flood carrying capacity and storage uap8CitV, and excavation or fill detrimental to the
environment.
b. Upon completion of installation of enoonVo| u8|ihns' sensitive amenhUco|areas and their buffers
must be restored to pre project configuration, replanted as required and provided with maintenance care until.
c All crossings must be designed for shored facilities in order to minimize adverse impacts and
reduce the number ofcrossings.
0. Construction Or maintenance of Essential Public Streets, Roads and Rights -of -Way as defined by
TIVIC 18,06285. provided the following criteria are mot:
For construction ofnew essential public streets, roads and rights ofway, ondefined by7MCSection
18.00.285. where avoidance efsensitive 3maohdna| arms isnot pooSib|o. impacts hJthe sensitive
a. Essential public streets, roads and rights of way, as byTIVIC Section 18.06.285.muSt
b-&Are designed and maintained to prevent erosion and avoid restricting the natural movement of groundwater.
— -----r------ ------�-- '—� -~—'---/ --------- --'—
Are located k)conform h8the topography SOthat minimum alteration Ofnatural conditions iSnecessary. The number
{fcrossings shall b8limited k)those necessary k)provide essential access.
C. -----r------ -----�---'-/ ---'---/ - -------- ----
Are constructed inaway that does not adversely affect the hydrologic quality ofthe wetland nrwatercourse and/or
its buffer. Where feasible, crossings must allow for combination with other essential utilities.
d.
n:tablished, at|osst5yars,|naddition, mitigation to offset impacts to scenSitive arcochhca|arms or their bufforG
ation ratios set forth in this chapter.
7. Public/Private Use and Access
8. Public and private access shall be limited to trails, boardwalks, covered or uncovered viewing
and seating 8re8O. footbridges only ifnecessary for access to other areas of the property, and displays /SVCh 88
interpretive SigO3gSOrkiOSkS\' and must be located in areas that have the lowest sensitivity 03 human disturbance
oralteration. Access features shall be the minimum dimensions necessary 0Davoid adverse impacts tVthe sensitive,
omOChUC3|area. Trails shall bSO0wider than 5feet and are only allowed iOthe outer half 25percent Ofthe buffer,
except for allowed wetland or stream crossings. For proposed wetland or watercourse crossings or trails, on
OSSCSCment of impacts to wet |OndkwatCrc8ur3o and buffer h/nCd8n /CCpCciOUy where the senSibvOarCachtical
miner onossngo, such on foot bridges orstepping stonos, for access to contiguous property. Crossings and trails
must be designed to avoid adverse impacts to c0nSitimC 2m3ChUC8| area functions. The Director may require
mechanisms to limit Or control public 3CceGS when environmental conditions w3n8n1 (such as temporary trail
closures during wildlife breeding season Ormigration S88SOO).
b. Public access must b8specifically developed for interpretive, educational Orresearch purposes by,
Orin cooperation with, the City Or8S part Ofthe adopted Tukwila Parks and Open 8p8C8 Plan. Phv3h9 footbridges
are allowed only for access across Gsensitive areGchUC3|area that bisects the property.
C. NOmotorized vehicle iSallowed within 8sensitive amzchdo8|area Orits buffer except as required
for necessary maintenance, agricultural management O[security.
d. Any public access U[interpretive displays developed along 8sensitive Jr8ochhua|area and its buffer
Page 9 of 42
e. Vegetative edges, structural barriers, signs or other measures must be provided wherever necessary
to protect sensitive ar acritical areas and their buffers by limiting access to designated public use or interpretive areas.
f. Access trails and footbridges must incorporate design features and materials that protect water
quality and allow adequate surface water and groundwater movement. Trails must be built of permeable materials.
g. Access trails and footbridges must be located where they do not disturb nesting, breeding and
rearing areas and must be designed so that sensitive plant and critical wildlife species are protected. Trails and
footbridges must be placed so as to not cause erosion or sedimentation, destabilization of watercourse banks,
interference with fish passage or significant removal of native vegetation. Footbridges must be anchored to prevent
their movement due to water level or flow fluctuations. Any work in the wetland or stream below the OHWM will
require additional federal and state permits.
8. Dredging, Digging or Filling may occur within a critical area or its buffer only with the permission of the
Director provided it meets mitigation sequencing requirements and is permitted under TMC 18.45.90
{alteration of wetland), TMC 18.45.110 (alteration of watercourse), or TMC 18.45.100 (areas of
geologic instability). Dredging, digging or filling shall only be permitted for flood control, improving water
quality and habitat enhancement unless otherwise permitted by this chapter.
critical arca or its buffer may occur only with thc
permission of the Director and only for the following purposes:
{) Uses -permitted• by TMC Sections 18.45.080,18.45.090, 18.45.1-10, 1 45.130;
{2) Maintenance of an existing watercourse;
{3) Enhancement or restoration of habitat in conformance with an approved mitigation plan
critical area study;
�4} Natural system interpretation, education or research when undertaken by, or in cooperation
with, the City;
{5) Flood control or water quality enhancement by the City;
{6) Maintenance of existing water quality controls, for normal maintenance needs and for any
diversion, rerouting, piping or other alteration permitted by TMC Chapter 18.45;
{7) Filling of abandoned mincs.
if) the water. Every effort will be made to perform such work at the time of year when the impact can be lee ened.
c. Upon completion of construction, the area affected must be restored to an appropriate grade,
established.
Removal of Hazardous . Only hazardous trees, as defined in Chapter 18.06.395, may be removed
from a sensitive areacritical area. In cases where the hazard is not obvious, an assessment by an
arborist certified by thc International Society of Arborists may be required by the Director. Tree
replacement in accordance with TMC Chapter 18.54 is required for any hazardous tree removed from a
sensitive areacritical area. Dead treesAny other vegetation (dead or living) may not be removed, unlee
they present a hazard to public safety or structures.
G— Permitted Uses Subject to Exception Approval. Other uses may be permitted upon receiving a
reasonable use exception pursuant to TMC Section 18.45.180. A use permitted through a reasonable use exception
shall conform to the procedures of TMC Chapter 18.45 and be consistent with the underlying zoning.
TMC Section 18.45.160.
(Ord. 2301 §1 (part), 2010)
18.45.075 Mitigation Sequencing
A. Applicants shall demonstrate that reasonable efforts have been examined with the intent to avoid and minimize
impacts to critical areas and critical area buffers. When an alteration to a critical area or its required buffer is proposed,
such alteration shall be avoided, minimized or compensated for in the following order of preference:
55
Page 10 of 42
1. Avoiding the impact altogether bynot takinclocertain action mparts ofanaction;
2. Minimizinq ohdna| area or critical area buffer impacts by limiting the deOree or magnitude of the action
and its implementation, byVSinq appropriate 03ChnV|0qy.OrbyC3kinOaffirmative steps h]avoid nrreduce impacts,
3. ReCUfyinq the impact byrepairing, rGh8bi|it3UnO Orr8S0Jhngthe affected environment;
4. Reducinq or eliminatinq the impact over time by preservation and maintenance operations during the life
nfthe actinn�
.
5. Compensatincl for the impact by replacing, enhancing, or providing substitute resources or environments;
and/or
0. MVnUDhnOthe impact and t@Nn0appropriate corrective measures.
18.45.80 Wetlands Designations, Ratings and Buffers
A. INE7IA8DQES/GNA77ONS.
1. For the purposes 0fTMCChapter 18.45'"weUand8^and "regulated wetlands" are
defined inthe Definitions chapter Ofthis title. Awetland boundary iSthe line delineating the outer edge Of8wetland
established by using the Washington State Wetland and Delineation Manual, as required by RCW 36.70A. 175
accordance with the approved federal wetland delineation manual and applicable regional supplement.
2. Wetland determinations and delineation of wetland boundaries shall be made by a qualified professional,
as described in TMC Section 18.45.040.
3. Wetland determinations and delineation or wetland boundaries must be conducted within no more than five
years Prior to the date of permit application,
Wetland areas withiR the City of Tukwila have GeFtaiR GharaGteFiSks and fURGtiGRS and have beeR
influenced bvurbanization and related disturbances, Wetland functions include, but are not limited to, the following:
Maintaining hydrologic functions (reducing peak flows, dccr asinC erosion, groundwater recharge, flood
storage); and
Providing habitat for plants, mammals, fish, birds, andamphibians.
B. NETLA8DRA0NGS—
VV8U8OdG Gh8U be designated in accordance with the VV8GhiOgk)O State VV8U8OdS Rating System for Western
VY8ShiOgk)O' (Washington State Department 0fEcology, August 2004. Publication #O4 06 0252014. PUb|iCFN0O #
14-O0-O28\,Or@Sotherwise amended byEcology 8GCategory i||'U|'OrIV. JSlisted below:
1. Category 1 wetlands are these that: FepFeSeRt a unique Aar raire we-flaand type; orii) are more sensitive
Jhigh level Vffunctions. T
listed by Washington Department of EGGIOgY and potentially found in Tukwila aFe Category 1:
a. Estuarine Relatively undi,-turbodestuarine wetlands (docowotcrtidal habitats with o range nffm:h
brackish marine water chemistry and daily tidal cycles, salt and brackish marshes, inbartid8|mudflats.bavu. sounds,
and coastal hvena\�
'.
b. Wetlands that perform many functions well and score at least 70 points in the VV8sharn
Washington Wetlands Rating System,
2. Category 11 wetlands om difficult, though not impossible, toreplace and provide high levels ofSome
Page 11 of 42
D�
functions. These wetlands occur more commonly than Category | wo#ando, but still need a relatively high level of
Tukwila are Category 11 wetlands:
b. Wetlands that pndhml functions well, Wetlands scoring between 51 09point.- (out of 100) on the
questions related Vothe functions present.
3. Category III wetlands have a moderate level of functions (scores between 30 and 50 points), Wetlands
4. Category IV wetlands have the lowest levels of functions (scores less than 30points) and are often
heavily disturbed. While these are wetlands that should be able to be replaced or improved, they still need protection
case bvcase basis.
C. WETLAND BUFFERS -
-5-.1. Purpono,A buffer area shall be established -adjacent to designated wetland areas. The purpose nf
the buffer area Sh8U be 03 protect the integrity and functions of the wetland area. Any land a|t8n8UOn must be located
out of the buffer areas as required by this section. Wetland buffers are intended in general to:
a. Minimize long-term impacts Of development On properties containing wetlands;
b. Protect wetlands from 8dv8nS8 impacts during development;
C. Preserve the edge of the wetland and its buffer for its critical habitat value;
d. Provide 8narea k)stabilize banks, 03absorb overflow during high water events and k)allow for slight
variation of aquatic system boundaries over time due to hydrologic or climatic effects;
8. Reduce erosion and increased surface water runV��
.
[ Reduce loss 0f0rdamage h)property;
g. Intercept fine sediments from surface water runoff and serve 03minimize water quality impacts; and
h. Protect the sensitive ar acritical area from human and domestic animal disturbances.
O. _Anundisturbed s8nniUvoar-aorbuffer may nubodtutnfor the yard sntbaokand landscape
requirements of the TN1C Chapter
E. 18.50and 18.52.
UFFER REQUIREMBVTS—
i. Buffer widths iOTable 18,45,OMO'1 have been established inaccordance with the best available science.
They are based onthe category 0fwetland and the habitat score.
CStobUShOdfrom the wetland edge:
b, Category III Wetland: 80 foot buffer.
57
Page 12 of 42
Table 18.45.080-1 Wetland Buffer Widths
CmteqorR
Wetland buffer width (ft).EcoUow 2014,hi_qh-imtmmmitVland use impact
Habitat
score
Habitat
score
Habitat
score
Habitat score
6~7
Habitat
score
Habitat score
<6
<6
6-7
8-9
8-9
Standard
Buffer
Alternate
Buffer if
impact
Standard
Buffer
Alternate Buffer
if impact
minimization
measures taken
AND buffer is
replanted,
Standard
Buffer
Alternate Buffer
if impact
minimization
measures taken
AND buffer is
replanted. Also,
minimization
measures
taken AND
buffer is
Also, 1O0feet
100 feet
replanted
veqetated
vegetated
corridor
corridor between
between
wetland and any
wetland and
nearby Priority
any nearby
Priority Habitats
is maintained
(see footnote 1\
Habitats is
maintained.
(see footnote 1)
1
100
75
150
110
300
225
0
100
75
150
110
300
225
U|
80
68
150
110
300
225
8/
50
40
50
48
50
40
(1)�Arelatively undisturbed, vegetated corridor 8t least 10]feet wide is protected
between the wetland and any nearby Priority Habitats as defined by the Washington State Department of
Fish and Wildlife, The corridor must b8protected for the entire distance between the wetland and the
Priority Habitat by some type of|eqa| protection such as nVnsonmhon easement. Presence or absence of
8 nearby habitat must be confirmed by qualified biologist, |fn0option for providing 8 corridor is 8voi|8b|8.
Table 18.45.080'1 may be used with the required measures in Table 18.45.080'2 alone.
Table18.45.080-2 Required Measures to Minimize Impacts to Wetlands
Disturbance
Noise
Required Measures to Minimize Impacts
0 Direct lights away from wetland
* Locate activity that qen8ratesnoise away from wetland
w |fwarranted, enhance exiStinqbuffer with native vu0et8UOn0|8nUnqs
adjacent tOnoise source
° For activities that qenonaharelatively continuous, potentially disruptive noise,
such as certain heavy industry Ormininq. establish an additional 10' heavily
vegetated buffer strip immediately adjacent b}the outer edge Ofwetland
buffer
Page 13 of 42
Disturbance
Required Measures to Minimize Impacts
Toxic runoff
•
Route all new, untreated runoff away from wetland while ensuring wetland is
•
not dewatered
Establish covenants limiting use of pesticides within 150 feet of wetland
•
Apply integrated pest management
Stormwater runoff
•
•
Retrofit stormwater detention and treatment for roads and existing adjacent
development
Prevent channelized flow from lawns that directly enters the buffer
•
Use Low Intensity Development (LID) techniques where appropriate (for
more information refer to the draina.e ordinance and manual)
Change in water regime
•
Infiltrate or treat, detain, and disperse into buffer new runoff from impervious
surfaces and new lawns
Pets and human disturbance
•
•
Use privacy fencing OR plant dense vegetation to delineate buffer edge and
to discourage disturbance using vegetation appropriate for the ecoregion
Place wetland and its buffer in a separate tract or protect with a
conservation easement
Dust
•
Use best management practices to control dust
E. BUFFER SETBACKS —
1. All commercial and industrial buildings shall be set back 15 feet and all other
development shall be set back 10 feet from the buffer's edge. The building setbacks shall be
measured from the foundation to the buffer's edge. Building plans shall also identify a 20-foot
area beyond the buffer setback within which the impacts of development will be reviewed.
2.The Director may waive setback requirements when a site plan demonstrates there will be no
impacts to the buffer from construction or occasional maintenance activities (see TMC Figure
18-2).
F. VARIATION OF STANDARD WETLAND BUFFER WIDTH-
2. The Director may reduce the standard wetland buffers only where the buffer
conditions arc currently degraded (due to existing development within the prescribed buffer
andlor lack of native vegetation) on a case b
0
planted setback from the top of the slope is maintained. Further, a geotechnical review of the
proposed buffer enhancement plan must determine the buffer enhancement can be
implemented without destabilizing the slope. The approved buffer width shall not result in
greater than a 50% reduction in width.
1. Buffer reduction with enhancementaveraqinq may be allowed by the Director as a Type 2 permit if the
total area of the buffer after averaging is equal to the area required without averaging and the buffer at its narrowest
point is never less than either'/4 of the required width or 75 feet for Category I and II, 50 feet for Category III, and 25
feet for Category IV, whichever is greater, and so Ionq as the following criteria is met:. -
with an approved buffer enhancement plan prepared by a qualified wetland biologist, if:
Additional protection to wetlands will be provided through the implementation of a buffer enhancement plan;
The existing condition of the buffer is degraded;
aid
Buffer enhancement includes, but is not limited to
the following:
or hydrology;
59
Page 14 of 42
wood duck boxes, bat boxes, snags, root . birdhouses and heron nesting areas; nr
Removing nonnative plant Species and noxious woods from the buffer ar o and replanting tho
or subject 8z2.c<1\above.
a. The wetland has significant ddfferennnsin characteristics that affect its habitat functions, and the
buffer is increased adjacent 0othe higher-f nnMoninq area of habitat or more -sensitive portion of the wetland and
decreased adjacent to the lower-functioninq or less -sensitive portion as demonstrated by a critical areas report.
h. There are no feasible alternatives k)the site d8Siqnthat could be accomplished without buffer
avenaginq, and the averaged buffer will not result in degradation of the wetland's functions and values an
demonstrated byacritical areas report.
C.Compliance with miiiqaU0nS80U8nCinqrequirements.
d.Compliance with TMC1O.45Vo08taUOnProtection and M8n8q8mentsection.
8. Submittal 0fbuffer enhancement plGn, midqah0n m0nib]hnq and maintenance plan 8|Unq with
financial quGnBnte8inaccordance with TIVIC 18.45.
2 Interrupted Buffer: Waiver for interrupted buffer may beallowed by the Director as a Type 2 permit if the followinq
criteria is met:
U The buffer is interrupted by a paved public or private road; legally constructed buildings� or legally
GpVn]v8Up3ddnq lots. This waiver does not apply tOaccessory structures such 83sheds and
qarogen;
i) The existinq legal improvement creates a substantial barrier to the buffer function-,
|i\ The interrupted buffer does not provide additional protection of the critical area from the proposed
development; and
iii) The interrupted buffer does not provide SiqnificGOthyd0|OqiC8[water quality and wildlife
functions.This waiver does not apply if larqe trees or other siqnificant native veqetation exists.
iv) Enhancement 0fr80aininqbuffer iSrequired iffeasible.
�3]Buffers for all types Ufwetlands will b9increased when they are determined k]b8particularly sensitive
to disturbance or the proposed development will create unusually adverse impacts. Any increase in the width of the
buffer shall be required only after completion of w8U8Od study by 8 qualified w8UGOdS Sp9Ci8|iSt p0f9SSi0O8| or
expert that documents the basis for such increased width. An increase in buffer width may be appropriate when:
8. The development proposal has the demonstrated potential for significant adverse impacts upon the
wetland that can b8mitigated by3nincreased buffer width; or;
b. The area Sen/8S as 3 habitat for endangered, threatened, sensitive Or monitor species listed
by the f8d8[8| government O[the State.
2-A. Every reasonable effort shall be made to maintain the existing viable native plant life in the buffers.
EnhaRGeMeRtS will ensuFe that slepe stability and wetland quality will be maintained er imprGved, ARy disturbaRGe
onn appropriate for the specific site asdetermined by the Director, If the vegetation must beremoved, orbecause Of
the o|tn/aUnns of the landscape the vegetation become., damaged Ordio
,8p|aoR existing vegetation along wetlands with comparable specimens, approved by the Dirertor, which will
restore buffer functions within five y rs
The Director shall require subsequent ronCnUvC GnUOnn and long term monitoring of the project ifzdvCr:0
impacts tOregulated wetlands o[their buffers are identified,
(Oni23GR§48,20Y2;Ord. 2301 §1(ponV,2010)
Page 15 of 42
18.45.90 Wetlands Uses, Alterations and Mitigation
A. No use Ordevelopment may occur in 8 and or its
buffer except usspecifically allowed bvTMC Chapter 1845. Any use ordevelopment allowed issubject hJ review
and approval by the Director. VVh9n8 v2qUinBd. 8 nOidg8UOn plan must b8developed and must comply with the
standards of mitigation required in TMC Chapter 18.45. Where unauthorized alterations occur within a critical area
or its buffer, the City will require the applicant to submit a chUC3| area study, that inC|Vd8S mi\iO8d0n. subject to
approval. The applicant shall be responsible for implementing the miUqadon and for additional penalties as
determined by the Director. In addition, federal and/or state authorization is required for directimpacts 10waters 0f
the United States Orthe State OfWashington.
B. AL7ERATIQN8-
1. A|t8r8UOnS to vv8U8ndS are discouraged and are limited 0Jthe minimum necessary for project fe8Sibi|ity.
Requests for alterations must be accompanied by mitigation plan, are subject to Director approval,
and may be approved only if the following findings are made:
8. The alteration complies with mitigation sequencing requirements,
b. The alteration will not adversely affect water quality;
C. The a|0anodnn will not adversely affect fish, wi|d|ifn, ortheir habitat;
d. The alteration will not have an adverse effect on drainage and/or storm water detention
capabilities;
8. The alteration will not lead to unstable earth conditions or create an erosion hazard or
contribute k)scouring enUnn8;
t The alteration will not bematerially detrimental k) any other property; and
q. The alteration will not have adverse effects on any other sensitive armcritical areas,; and
g,h. Complies with the maintenance and monitoring section.
2. Alterations are not permitted 03 Category | and || wetlands UO|8SS Sp8CihC8Uy exempted under
the provisions 0fTMCChapter 1O.45.
3. Alterations to Category III and lVwetlands are allowed only where unavoidable and adequate mitigation
i8carried out inaccordance with the standards Ofthis section.
4. Alterations to isolated Category |V wetlands less than 1.000 square feet in size that meet all of the
fO||0*iOO C0OdiU0nS are 8UOwSd.-ny vvhSn8 unavoidable and adequate 0ihg8UOO is C8OiSd out in
accordance with the standards of TMC Section 18.45.090this section.5.Wetland that are less than 1000
,square feet ma\b8exempted where ithas been Sh0mnbythe applicant that
o. lth8yare not associated with 8riparian corridor,
b. They are not associated with shorelines of the state or their associated buffers.
C. lth8yare not part Of8wetland mOS8iC-
d. They, do not contain habitat identified as 9GGen1i8| for |Oc3| pOpu|8dOnG Of phOh1v species identified by the
VV8ShiOg1OO State Department OfFish and VYi|d|ife`8Od
8,8. They dOnot score 2OOpoints Orgreater for habitat iOthe Western Washington Wetland Rating System.
owetland 8xits required buffer is proposed,such alteration shall bSavoided, minimized 0rcompensated for in
the following order of :
1� Avoiding the impact altogether bvnot taking o certain action 0rparts Uf8naction;
and its imolemOntnUon, by using appropriate technology, or by taking affirmative steps h}avoid Orreduce impacts;
the life of the action;
61
Page 16 of 42
environments; and/or
6. Monitoring the impact and taking appropriate corrective measures.
the Director. Wetland and/or buffer alteration or relocation may be allowed only when a mitigation plan clearly
2. The scope and content of a mitigation plan shall be decided on a case by case basis taking into account
increase, the mitigation measures to offset these impacts will increase in number and complexity.
3. For wetlands, the format of the mitigation plan should follow that established in Wetland Mitigation in
Washington State, Part 2 Developing Mitigation Plans (Washington Department of Ecology, Corps of Engineers,
EPA, March 2006 or as amended).
1. The components of a complete mitigation plan arc as follows:
a. Baseline information of quantitative data collection or a review and synthesis of existing data for
both the project impact zone and the proposed mitigation site.
b. Environmental goals and objectives that describe the purposes of the mitigation measures. This
functions.
c. Performance standards of the specific criteria for fulfilling environmental goals and for beginning
targets, habitat diversity indices, or other ecological, geological or hydrological criteria.
d. A detailed construction plan of the written specifications and descriptions of mitigation techniques.
This plan should include the proposed construction sequence, and construction management, and tree protection
c. A monitoring and/or evaluation program that outlines the approach for ae essing a completed
project for the specified monitoring period, at least 5 y ars. An outline shall be included that spells out how the
monitoring data will be evaluated by agencies that are tracking the mitigation project's progress.
f. Contingency plan identifying potential courses of
g. Performance security or other assurance devices as described in TMC Section 18.15.210
€C.MITIGATION STANDARDS.
1) Types of Wetland Mitigation:
a) Mitigation for wetlands shall follow the mitigation sequencing steps in this chapter and may include the
following types of actions in order of decreasing preference:
1.Restoration:
a. Re-establishment. The manipulation of the physical, chemical or biological characteristics of a site with
the goal of restoring wetland functions to a former wetland, resulting in a net increase in wetland acres and
functions;
b. Rehabilitation. The manipulation of the physical, chemical or biological characteristics of a site with the
goal of repairing historic functions and processes of a degraded wetland, resulting in a gain in wetland
functions but not acreage;
2. Creation (establishment).The manipulation of the physical, chemical or biological
characteristics to develop a wetland on an upland or deepwater site, where a biological
wetland did not previously exist;
3. Enhancement. The manipulation of the physical, chemical or biological characteristics to
heighten, intensify, or improve specific functions (such as vegetation) or to change the
Page 17 of 42
growth stage or composition of the vegetation present, resulting in a change in wetland
functions but not in a gain in wetland acreage.
4. A combination of the three types.
b) Required mitigation ratios are described in TMC Section 18.45.090.E.1.b.(1). Alternate mitigation ratios
may be accepted by the Director upon presentation of justification based on best available science that
shows the proposed compensation represents a roughly proportional exchange for the proposed impacts.
1. Alterations are not permitted to Category I or II wetlands unless specifically exempted
under the provisions of this program. When alterations are allowed, mitigation ratios
for Category I wetlands shall be at a 4:1 for creation or re- establishment, 8:1
for rehabilitation, and 16:1 for enhancement. Mitigation ratios for Category II
wetlands shall be at 3:1 for creation or re-establishment, 6:1 for rehabilitation and
12:1 for enhancement. Creation or re-establishment shall be contiguous to the
wetland, unless an exception is authorized by the Director. For Category II estuarine
wetlands, re-establishment, creation and enhancement ratios will be decided on a
case -by -case basis.
2. Alterations to Category III wetlands are prohibited except where unavoidable and
mitigation sequencing in accordance with this chapter has been utilized and where
mitigation is carried out in accordance with the standards in the section. Mitigation
for any alteration to a Category III wetland must be provided at a ratio of 2:1 for
creation or re-establishment, 4:1 for rehabilitation and 8:1 for enhancement alone.
3. Mitigation for alteration to a Category IV wetland will be 1.5:1 for creation or re-
establishment, 3:1 for rehabilitation or 6:1 for enhancement. Where only a portion
of a Category IV wetland is filled, the potential functionality of the remaining
reduced wetland must be considered in mitigation planning.
3:4. Mitigation for alteration to wetland buffers will be 1:1.
2) The following shall be considered the minimum performance standards for approved wetland alterations:
a. Wetland functions improved over those of the original conditions.
b. Hydrologic conditions and hydroperiods are improved over existing conditions and the specific hydrologic
performance standards specified in the approved mitigation plan are achieved.
c. Square feetAcr agc requirements for creation, re- establishment, rehabilitation or enhancement and for
proposed wetland classes are met.
d. Vegetation native to the Pacific Northwest is installed and vegetation survival and coverage standards over time
are met and maintained.
e. Habitat features are installed, if habitat is one of the functions to be improved.
f. Buffer and bank conditions and functions exceed the original state.
3)Maintenance and monitoring of mitigation shall be done by the property owner for a period of no less than five
years and for ten years when the mitigation plan includes establishing forested wetland and/or buffers.
Maintenance shall be carried out in accordance with the approved mitigation plan. Monitoring reports must be
submitted to the City for review with the frequency specified in the approved mitigation plan.
mitigation to a wetland mitigation bank using the criteria in 4.a. through 4.f. below. The Director must
determine aurove the number of wetland mitigation bank credits required to meet the mitigation ratios
established in TMC Chapter 18.45.
a, Off site mitigation is proposed in a wetland mitigation bank that has been approved by au
appropriate agencies, including the Department of Ecology, Corps of Engineers, EPA and
certified under state rules; and
b. The proposed wetland alteration is within the designated service area of the wetland bank; and
c.The applicant provides a justification for the number of credits proposed; and
d. The mitigation achieved through the number of credits required meets the intent of TMC Chapter 18.15; and
63
Page 18 of 42
with the number ofwetland credits required; and
f, The applicant provides ocopy ofthe wetland bank ledger demonstrating that the approved number ofomdhG
has been removed from the bank.
�D.WETLA&0AND BUFFER MITIGATION LOCATION.
1.1n instances vvhV[e portions of e wetland or vv8Uend buffer impacted by development remain after buffer averaginq'
mitigation for buffer impacts shall be provided on -site, if feasible. Where an essential public road, street or right-of-way or
essential public utility cannot avoid reducing ebuffer bymore thoF-5U�,alterations, additional buffer enhancement must
bncarried out 8tother locations around the impacted wetland.
2_On'Sit8mitigation for wetland impacts shall b8provided, except where the applicant can demonstrate that:
�a. On'si0awetland mitigation in not scientifically feasible duo to problems with hydrology, soils,
waves or other factors; or
e1b]Nitig8UOn is not pn8CUC8| due to potentially adverse impact from surrounding land uses; or
h,L.ExiSting functions created at the site of the proposed restoration are significantly greater than
lost wetland functions �. Or
d. Regional goals for flood storage, flood conveyance, habitat or other wetland functions have
been established and strongly justify location Of mitigation at 8OCkh8r site. and where off -site mitiQ@tioO is
d8nl0n5Xn@ted to provide 8 O,e@1Sr8Co|0OiCa| benefit to the watershed. Refer to 2005 VYR|A9 S8|mOO Habitat Plan
or as amended, for potential offsite mitigation locations.
5. Purchase of mitigation credits through mitigation banks and inlieu fee programs is preferred over
p8nnitte8responsible offsite mitigation.
4. The Community Development Director may approve, throuqh a Type 2 decision, the transfer of wetland mitiqation to a
wetland mitigation bank orin'|ieu foe 0rogram using the criteria in4a.a. through 4@.tbelow. Wetland mitigation bank
Cr8di shall be determined by the Certified
mitigation banking orin-lieu fee in»tnumonL
a.Off-site miUq8tiUn is proposed in 8 wetland mitigation bank that has been approved by all
appropriate 8q8nCi8S, including the Department of ECo|0qy, Corps of EnqineerS. EPA and certified
under state rules; and
bThe proposed wetland G|t8n8dOn is within the designated service area 8fthe wetland bank; and
C. The applicant provides a iusUfiootiVn for the number nfcredits proposed; and
d. The miUqaUOn achieved through the number 0fcredits n8quiv8U 088tS the intent OfTKXC Chapter
18.45; and
e.The Director bases the decision on awhtten staff report, ev8|uoUnq the equivalence of the lost
wetland funCdOOS with the number 0fwetland credits required; and
fThe applicant provides a copy of the wetland bank |edqardomnnotnytinq that the approved number
of credits has been removed from the bank,
Off -site mitigation nhoU occur within the same watershed where the wetland loss occurred.
,5.VVherSUff'si0a miUq8dOn location in proposed it shall comply with thnfn||Vwinq criteria:
8.Mitig8tionsites located within the Tukwila City limits are preferred-.
b.K8iUq3dnn bank or in -lieu fee option in not feasible.
C.Th8 proposed 0iti08bVO will not alter or increase buffers On 8diaCSOt p[Op9rU8S without their p8nni3SiOO.
L Hnwever.t
0.Th8Director may approve offsite mitigation sites outside the city upon finding that:
UAd8quatB 083SureS have been taken to 8OSu[8 the OOO'd8v8|Opm8Ot8Od |OOg-t8nn viability of the nlitig8dOO site;
and
0Ad8qu3V8 CU0ndiO3UOO with the other affected |008| juhSdiCUOO has OCCun8d.
jU|nse|echng permitte8 responsible off.-itemitigation sites, The app|iC3n0c :hz|| has selected 3 site in 8
|0C8d0O where the targeted functions can reasonably be performed and sustained and has&hg pursued
sites iOthe following order Ufpreference:
Sites within the immediate drainage Sub'b8Sin;
Page 19 of 42
Sites within the next higher drainage sub -basin; and
Sites within Green/Duwamish River basin.
77O0TIMING — Mitigation projects shall b8completed prior k}activities that will permanently disturb
wetlands and either prior to or immediately after activities that will temporarily disturb wetlands. Construction
of mitigation projects shall bmtimed Vureduce impacts Vuexisting wildlife, flora and water quality, and shall be
completed prior to use Or occupancy of the activity Or development. The Director may allow activities that
permanently disturb wetlands prior to implementation of the mitigation plan under the following circumstances:
1. TOallow planting Orr8'Y8g8t8UOn to occur during optimal weather conditions;
2. TOavoid disturbance during critical wildlife periods; Ur
3. TO account for unique site COnSXx8intS that dictate construction timing Urphasing.
(Ont 2301§/(panU, 2010)
Fk0ETLANDMITIGATION PLAN CONTENT
1. The mitigation plan shall bedeveloped aspart nfacritical area study bvoqualified professional, Wetland
and/or buffer alteration 0/relocation may b8allowed only when @miUq8UOnplan clearly demonstrates that the
changes would be an improvement of wetland and buffer quantitative and qualitative functions. The plan shall
show how water quality, habitat, and hydrology would beimproved.
2. The SCOp8 and content Ofa mitiq8dOn plan Sh8U be decided on 8 C8S8'by'C8S8 baSiStGNnq into account
the degree of impact and the extent of the mitigation measures needed. As the impacts to the critical area
increase, the miUq8UOnmeasures 0Doffset these impacts will increase innumber and complexity.
3 For wot|ands, the format of the mitigation plan should huUnw that established in Wetland Mitigation in
VVaShin0k)n GiG03, Part 2— Developing MiUOaU0n Plans (Washington Department OfECV|nqy. Corps
cfEnqin8erS. EPA. March 2006 or as amended).
4. The components ofocomplete mitigation plan are anfollows:
a. Baseline information of quantitative data COU8CUOn Or G review and synthesis 0fexiS1inq data for both
the project impact zone and the proposed mitigation site.
b. Environmental goals and objectives that describe the purposes 0fthe mitiq8d0nmeasures. This should
include 8 U8SC[i0d0V of site S8|8CdOO Cht8ha. id9OhfiCadOn OftGul8t 8v8|u8UoD S09deS and resource
functions.
C. P8rfnnn8nC8 standards of the specific Chk*ha for fulfilling environmental gO8|S and for bSqiOOinq
remedial action 0rDOntinq8nCymeasures. They may include water quality standards, species richness
and div8nSityt8nl8tS. habitat diversity iDdiC8S. Orother 8CO|OqiCGi 0eO|0qiC8| 0[hyd0|OqiC8| Ch18h8,
d. A detailed construction plan of the written specifications and descriptions of mitiqation techniques. This
plan should include the proposed construction sequence, CVnoUuodOn manaqem8nt and tree
p[Ut8C1i0n and be accompanied by detailed site diagrams and blueprints that are an int8qB|
requirement ofany development proposal.
P. A m0niO3riOq and/or evaluation program that outlines the performance standards and methods for
asoessinqwhether those performance standards are achieved durinq the specified moniO3rinq period,
at least years. At minimum, the monihzhnO plan ShnU|d addneSnveqet3Uvo COver. survival, and
species diversity. Any project that 8|1e[S the dimensions of w8UGOd or Cn08ieS 8 new w8U8OU 5h8||
also monitor wetland hydroloqy. An outline shall be included that spells out how the monitoring data will
beevaluated by8VenCiGSthat are tracking the 0itiV8dOnp0ieCt'Sp0gnSSS,
[ C0nUnOenCyp|onidenUfyinq0ot8nb8|cOur3eSofaciiVnandanyCOrr8ctiv8m9aSU/e3k}beC3ken*hen
m0ni0uhnqV,evaluation indicates project performance standards have not been met.
q� Performance security O[other assurance devices 8Sdescribed iDTMCSection 10.4521O.
18.45.100 Watercourse Designations, Ratings and Buffers
A. WATERCOURSE RATINGS. Watercourse ratings are consistent with the Washington Department of Natural
Resources water typing categories C222'18'03O\oraSamended,
which are based on the existing habitat functions and are ratclassified as follows:
65
Page 20 of 42
1.Type 44S)Watercourse: Watercourses inventoried 8SShorelines 0fthe State, under RCYV
80.58.Th888 watercourses shall bSregulated under TMCChapter 18.44' Shoreline Overlay.
2.TvpV -2-(F) Watercourse: Those watercourses that are known to be used by fish or meet
the physical criteria k)bepotentially used byfish (as estab|ished in VVAC 222'16'031(3) Vr as
amended) and that have perennial /y88r'rOund\Urseasonal flows.
3.Type 34Np)VYe&sv:ouBo: Those watercourses that have perennial flows and d0not meet
the criteria of Type F stream Or have been proven not to contain fish using methods d8SChb8d
inthe Forest Practices Board Manual Section 13.
4.Tvpe 4 (Ns) VV8t8vCUunSS: Those wat8nCOU08S that have intermittent flows /d0 not have
surface flow during 8tleast some portion Ufthe year) and -.-dOnot meet the physical criteria OfGType
Fwatercourse; orhave been proven tonot support fish uoinqmethods described inthe Forest Practices
Board Manual Section 13.
B. WATERCOURSE BUFFERS -Any land alteration must be located out of the buffer areas as required
by this section. Watercourse buffers are intended ingeneral to:
1. Minimize long-term impacts of development On properties containing watercourses;
2.Protect the watercourse from adverse impacts during development;
3. Preserve the edge of the watercourse and its buffer for its critical habitat value;
4. Provide shading to maintain stable water temperatures and vegetative cover for additional
wildlife habitat;
5.P0vidS input of organic debris and uptake of nutrients;
6. Provide an area to stabilize banks, to absorb overflow during high water events and to
allow for slight variation Of 8qu8UC SySU3m boundaries over time due 03 hydrologic Or dinn3tiC
effects;
7. Reduce erosion and increased surface water runO��
.
O. Reduce loss of, nrdamage to, property;
9.|nt8rcSpt fine SSdinl8nt; from surface water runoff and serve to minimize water quality
impacts; and
10. Protect the sensitive ococridco| area from human and dn0mnbo animal
diS1U[b3OD8.
An undisturbed and hiqh qualiNsensitive areacritical area or buffer may substitute for the yard setback and
landscape requirements OfTK8CChapter 18.5Oand 18.52.
C. WATERCOURSE BUFFER WIDTHS - The following buffer vvidtho, measured from the Ordinary
High YV31er Mark (OHYVM). apply to each side Of 3 wGt9nCVVrSS. If the 0HVYM cannot b8determined, then the
buffer will be m83Su[8d from the top Ofbank:
1. Type 4-4f)VV8t8[COunSS: Regulated under TK4CChapter 18.44'Shoreline Overlay.
2. Type 2(F)Watercourse: 100-foOhwid8buffer.
3. Type 3,4Np)VV318rcUu[8S: St8nd8[dMO-fhOt+wid8 buffer-,; 8|t8rD819 buffer in the 50-65 rGncle a||Ovved
with buffer enhancement.
4. Type 4(NS)Watercourse: 50'fOOt-wid8buffe[.
D. BUFFERSE7BACKS-
1. All commercial and industrial buildings shall be set back 15feet and all other development shall bS
set back 10feet. Building setbacks Gh8U be measured from the foundation to the buffer's edge. Building plans
Sh8|| also identify 8 20'fo0t area beyond the buffer setback within which the impacts of development will b8
reviewed.
2. The Director may waive setback requirements when 8site plan demonstrates there will benOimpacts
tUthe buffer from CUOSt[uctiOO or OCCGSiOO8| m8iOt8O8OC8 activities (S88 TK4C Figure 18'2).
E. VARIATION OF STANDARD WATERCOURSE BUFFBR0VDTH-
1, The Director may reduce the standard watercourse buffers 8nocase bycase basis, only where the
buffer is significantly degraded (due to existing development within the prescribed buffer width, the presence
of -significant amount of invasive vegetation
provided the remaining buffer is enhanced in accordance with an approved buffer enhancement plan, prepared by
Page 21 of 42
that includes (]uoo | slopes on the landward portion of the buffer, o buffer reduction may be o|lowod if the
proposed redUGt'GR 46 OR the area with the Class 1 slopes, and a 10 foet plaRted setbaGk from the tGp of the slope is
maiRtaiRed. Further, a geeteGhRiGal FeVi8W Of the proposed buffer 8RhaRGeFR8Rt pIaR must d8t8FMiRO that the buffer
enhancement can be implemented without destabilizing the slopc. The approved buffer width shall not result in
D;reGtc)r that it will not result direGt, indire6t or long teFFR adverse 'FRPaGtS to WateFGGLIFSeS, and that'.
a. The buffer vegetated and iRGIudes aR E)R site buffer eRhanGeMeRt plaR prepared by a qualified
professional, to retain existing native vegetation and install additional Rative vegetatien in order to improve the
buffer function; or
If there is no significant vegetation in the bufer, a buffer may be reduced only if an on-6ite buffer
enhaRGemeRt plaR Is provided. The pIaR must IRGIude using a variety ef native that improves
the functional attributes ofthe buffer and provides additional protection for the wotonoumofunctions, At
1Buffer averaqinq may be allowed by the Director asGType 2decision if the total area of the buffer after
averaging is equal to the area required withouaveraginqand the buffer otits narrowest point isnever less
than either 1/40fthe required width; and the fn||Owin0criteria i3mGt-.:
8. The watercourse has Siqnific8rddifferenD8S in characteristics that affect its habitat functions, and the
buffer isincreased adjacent hothe higher -functioning omanfhabibs1ormom'oensidvepnrtionofthewnUand
and decreased adjacent iUthe lower -functioning Or|8SS'S8nSidvepOrdOnGSdSmOnStn9iedbyGCh1iC8|an3aS
report from aqualified wetland professional.
b. There are no feasible alternatives to the site design that could be accomplished without buffer
averaqinq, and the averaqed buffer will not result in deqradation of the wetland's functions and values as
demonstrated byacritical areas report.
o.Compliance with mitigation soquenoinqrequirements.
d. Compliance with TMC 18.45Vegetodon Protection and Management section.
8.Submittal Ufbuffer enhancement plan, 0iUOGd000OnitOhnOand maintenance plan along with financial
guarantee in accordance with Tk8C 18.45.
f.Buffer avnr8qinOwill not adversely affect water quality.
q.N0adverse affect 0owater temperature Vrshade potential per 2O11 VVashiOqh}OState Department 0f
ECO|O0y'SGreen River Temperature Total Maximum Daily Load assessment OrUSamended,
2. Interrupted Buffer: Waiver for interrupted buffer may be allowed by the Director as a Type
2 permit if it complies with the followinq:
i) The buffer isinterrupted byGpaved public 0rprivate road; leW8|lyconstructed bui|dinqS;Or
|eqalyGpprovod padkinq lots. This waiver does not apply tnaccessory structures such as sheds and
q@n8qeS.
') ThRexisdnq leqal improvement creates @ substantial barrier 03the buffer function,
iii) The interrupted buffer does not provide additional protection of the chdc8| area from the
proposed development; and
iv) The interrupted buffer does not provide significant kvdn3|OgiC8|, w8[6[ quality and wildlife
hunctinn37hiS waiver does not apply if|8r0e trees Orother SiOnifiC8nt native vegetation exists.
v)Enhancement Ofremaining buffer iSrequired iffeasible.
67
Page 22 of 42
2.
3. Buffers for all types of watercourses will be increased when they are determined to be particularly sensitive
to disturbance or the proposed development will create unusually adverse impacts. Any increase in the width
of the buffer shall be required only after completion of a watercourse study by a qualified specialist
professional or expert that documents the basis for such increased width. An increase in buffer width may
be appropriate when:
a. The development proposal has the demonstrated potential for significant adverse impacts upon the
watercourse that can be mitigated by an increased buffer width; or
b. The area serves as habitat for endangered, threatened, sensitive or monitor species listed by
the federal government or the State.
invasive significant trees in the buffers. Vegetation may be removed from the buffer as part of an enhancement
plan approved by the Director. Enhancements will ensure that slope stability and watercourse quality will bo
vegetation must be removed, or because of the alterations of the landscape the vegetation becomes damaged or
dies, then the applicant for a permit must replace existing vegetation along watercourses with comparable
specimens, approved by the Director, that will restore buffer functions within five years.
adverse impacts to regulated watercourses or their buffers are identified.
(Ord. 2301 §1 (part), 2010)
18.45.110 Watercourse Alterations and Mitigation
A. WATERCOURSE ALTERATIONS. No use or development may occur in a watercourse or its buffer except
as specifically allowed by TMC Chapter 18.45. Any use or development allowed is subject to the standards of
TMC Chapter 18.45.
B. ALTERATIONS.
Daylighting and meandering of watercourses is encouraged. Culvert replacement is required where
applicable, and upgrades are required to meet State standards.. Piping, dredging, diverting or
rerouting is discouraged. Culverts are piped segments of streams which flow under a road, trail
or driveway. Daylighting of a stream refers to taking a stream out of a pipe which is flowing
underground, but not necessarily under a road. All watercourse alterations shall be carried out as
specified by the State Department of Fish and Wildlife in accordance with an approved Hydraulic Project
Approval (HPA).
1. The City encourages daylighting of a watercourse that is located in a pipe or meandering of a
previously altered watercourse to restore the stream to a more natural and open condition. As an
incentive for daylighting the Director may approve reduced buffers or setbacks.
Daylighting or meandering of a watercourse is only permitted if the following criteria
are met:
a) The values and functions of the watercourse are improved including reducing stream flow during storm
and flood events, and providing fish and wildlife habitat.
b) No adverse impact to fish are expected to occur
c) Water quality is equal or better than existing condition
d) Hydraulic capacity is maintained within the new channel
e) The watercourse design complies with the Washington Department of Fish and
Wildlife Water Crossing Design Guidelines manual 2013 or as amended.
Page 23 of 42
2. On properties with culverts that are being developed or re -developed, or when stream crossings in public or private
rights -of -way are being replaced, existing culverts that carry fish -bearing watercourses or those that could bear
fish (based on the criteria in WAC 222-16-031, Washington Forest Practices Rules and Regulations), shall be
upgraded to meet the standards in the Washington Department of Fish and Wildlife Water Crossing
Design Guidelines manual 2013 or as amended if technicallyfeasible. Any culvert replacement shall comply
with the following criteria:
a) The values and functions of the watercourse are improved including reducing stream flow during storm
and flood events, and providing fish and wildlife habitat.
b) No adverse impact to fish are expected to occur
c) Water quality is equal or better than existing condition
d) Hydraulic capacity is maintained within the new channel
e) The watercourse design complies with the Washington Department of Fish and
Wildlife Water Crossing Design Guidelines manual 2013 or as amended.
13. Piping, dredging, diverting or rerouting of any watercourse shall be avoided, if possible. Relocation of a
watercourse or installation of a bridge is preferred to piping. If piping occurs in a watercourse, it shall be limited to the
degree necessary for stream crossings for access. Additionally, these alterations may only occur with the permission
of the Director as a Type 2 decision and subject to mitigation sequencing; and requires an approved mitigation plan; and
shall meet the following criteria:, -
a) Any watercourse that has critical wildlife habitat, or is necessary for the life cycle or spawning of salmonids, shall not
The watercourse
alteration shall comply with the standards in current use and the standards of the Washington Department of Fish
and Wildlife in the "Water Crossing Design Guidelines" manual (2013 or as amended).
b) The watercourse alteration shall not cause adverse impacts to fish, confine the channel or floodplain,
or adversely affect riparian habitat (including downstream habitat).
c)
a) —Maintenance dredging of watercourses shall be allowed only when necessary to protect public safety,
structures and fish assa a and shall be done as infre uentl as ossible. on -term solutions such as stormwater
retrofits are preferred over ongoing maintenance dredging.:
d)
b) Stormwater runoff shall be detained and infiltrated to preserve the existing hydrology of the
watercourse. channel's dominant discharge.
e) All construction shall be designed to have the least adverse impact on the watercourse, buffer
and surrounding environment. Construction shall minimize sedimentation through implementation of best
management practices for erosion control.
All watercourse alterations- shall be carried out or constructed during periods of low flow, or as
cpecified by the State Department of Fish and Wildlife in accordance with an approved Hydraulic Project Approval
(H
c)
d) A watercourse may be rerouted or day lighted as a mitigation measure to improve watercourse function.
f) As a condition of approval, the Director may require water quality monitoring for stormwater
discharges to streams, and additional treatment of stormwater if water quality standards are not being met.
a. Permanent piping of any watercourse should be avoided. Relocation of a watercourse or installation
requirements the degree necessary for stream crossings for access and shall require approval of the Director._
69
Page 24of42
b. Piping of Type 1 S watercourses shall not be
permitted-
c. Piping may be allowed in watercourses if it is necessary for access purposes. In all
watercourses, it must be demonstrated that the piping will not cause adverse impacts to fish, confine thc channel
_(1). The conveyance system shall be designed to comply with the standards in current use and
recommended by the Department of Public Works and the standards of the Washington Department of Fish
(2a4).g.1 Where allowed, piping shall be limited to the shortest length possible as determined by
the Director to allow access onto a property.
h). Where water is piped for an access point, those driveways or entrances shall be consolidated to serve
multiple properties where possible, and to minimize the length of piping.
"). Piping shall not create an entry point for road runoff, create downstream scour, or cause erosion or
sedimentation
c) All watercourse crossings shall be de signed to accommodate fish passage,
unless technically not feasible.
jyWater quality must be as good or better for any water exiting the pipe as for the water entering the pipe, and
flow must be comparable.
f. All construction shall be designed to have thc least adverse impact on the watercourse, buffer
and surrounding environment.
g. All piping or other alterations shall be carried out or constructed during periods of low flow, or as
specified by the State Department of Fish and Wildlife in accordance with an approved Hydraulics
PermitHydraulic Project Approval (HPA).
h. On properties being developed or rc developed, or when str am crossings in public or private
fish (based on the criteria in WAC 222 16 031, Washington Forest Practices Rules and Regulations), shall be
upgraded to meet the standards in the WDFW manual "Design of Road Culverts for Fish Passage" (2003 or as
updated) if technically feasible.
C. MITIGATION PLAN CONTENT. All impacts to a watcr course that degrade thc functions of thc watercourse
or its buffer shall be avoided. If alteration to the watercourse or buffer is unavoidable, all adverse impacts
resulting from a development proposal or alteration shall be mitigated in accordance with an approved mitigation
plan as described below.
a) Mitigation plans shall be completed for any proposals of dredging, filling, diverting, piping and
wildlife and fish habitat, and general watercourse quality would be improved.
b) The scope and content of a mitigation plan shall be decided on a case by case basis taking into account
the degree of impact and extent of mitigation measures needed. As the impacts to the watercourse or its buffer
increase, the mitigation plan to offset these impacts will increase in extent and complexity.
Page 25 of 42
d The components ofacomplete mitigation plan are asfollows:
o. Baseline information including existing watercourse conditions such as hydrologic patterns/flow
rztgs, stream gradient, bank full width, stream bed oondidonn, bank oondiUons, fish and other wildlife use, in
stream stmdums, riparian nondidonn, buffer chenactchntics, water quality, fish barriers and other relevant
information.
U. Environmental goals and objectives that describe the purposes of the mitigation measures. This
should include a description of -site selection criteria, identification of target evaluation species and functions.
u, Performance standards for fulfilling onvi mnmonta|goals and objectives and for triggering remedial
action or contingency mqpeum:. Performance standards may include water quality standonda, species hohnaoo
and diversity torgcts, habitat diversity i diocn, creation of fish habitat, or other ecological, geological orhydrological
criteria.
d, Detailed construction plan of the written -specifications and descriptions ofmitigation techniques.
by detailed site diagrams and blU8PFiRt6 that are aR iRtegral reqUiFeMeRt c)f aRy development pF()po,-
project. At least five years of monitoring is required. n outline shall beincluded that spells out how the moniioh g
data will be evaluated by agenGies that are traGkiRg the mitigatiOR pFejeGt's proGess. For projeGts that disGharge
dDrmwterN8stream, the Director maynequire water quality monitoring.
f. Contingency plan identifying potential courses nf action and any corrective measures 0nbotaken
when monih)Fing or evaluation indicates project performance standards have not been met,
[-.C]NTIGATION S74NQARQS—
a) The Washington "Stream shere PFogram, WaShinglon Department ef FiGelegy, US Fish and Wildlife
8ervioe. Washington Department of Fish and VVi|d|ifc. 2004 or as amended) nho|| be used as 8oct Available
1) The following shall be considered the minimum standards for approved stream alterationsmitiqation projects:
8. Maintenance Or improvement Ofstream channel habitat and dimensions such that the fisheries
habitat functions Ofthe compensatory stream reach meet Orexceed that Ofthe original stream;
b. Bank and buffer configuration n2Sh}red to an enhanced state;
C. Channel, bank and buffer areas replanted with native vegetation that improves up on the original
condition inspecies diversity and density;
d. St[880 Ch8OO8| bed and bi0M|t0UOD 8yS180S 8qUiV@|Snt to ur/in the SGSe Of public drainage
mint8nJno8projects) 3ndb8ttS[th8ninth80[igiO8|Stn8Gnl(inth8oaSg0fotherkindnOfp j8ChS\;
e. Original fish and wildlife habitat enhanced un|8GS technically not fe8Sib|e�nd,
�f. |f0nSi0H mibq8U0n is not pO3Sib|8 and 03 ensure there is no net |QSS of watercourse functions inC|UdiOq
Sh8diDqthe applicants may payinto aOiOlieu fund ifavailable 0nensure that projects are fV||yOlitiO3U3d.
2) R8|OC8bOO of N0t8rcOunS8 Sh8U not [8Su|t in the new sensitive or aC[i1iCa| area 0[buffer extending beyond the
development site and onto adjacent property without the written agreement Ofthe affected property owners.
�D.&I77GA77O0 TIMING — Department of Community Development -approved plans as Type 2 decision must
have the mitigation COnSt0CtiOO COnlp|8t8d before the existing vv8t8rc0unS8 CGO be modified. The Director may
8UVvv 8ChvideS that permanently disturb 3watercourse prior tOimplementation Ofthe mitigation plan under the
following circumstances:
71
Page 26 of 42
To allow planting Or to occur during optimal weather conditions; or
To avoid disturbance during critical wildlife periods;
or
TO account for unique site constraints that dictate construction timing or phasing.
E. MITIGATION PLAN CONTENT. All impacts to a water- course 1hatdeqrade the functions of the watercourse
or its buffer shall be avoided. If alteration to the watercourse or buffer is unavoidable, all adverse impacts resultinq
from g development p0pOS8| or alteration Sh8U be miUqat8d in accordance with an approved miUA8tiOn plan 83
described below.
8. Mhiq8dOn plans 3h8U be completed for any proposals Of
dredging, filling, diverting, piping and rerouting ofwatercourses
or buffer impacts and shall be developed as part 0fg ChUCa|
area study bya qualified professional. The plan must show how
water que|ih/, treatment, erosion ountm[ pollution naduc1ion,
wildlife and fish habitat, and qen8r8|watercourse quality would
be improved.
b. The scope and content of a mitiqation plan shall be decided on a case -by -case basis takinq into account
the deqr8e Ofimpact and extent Ofmitigation m88Sur83 needed. As the impacts to the watercourse or its buffer
increase, the mitigation plan to offset these impacts will increase in extent and complexity.
C. The components Of8complete mitigation plan are 8Sfollows:
i Baseline information including existing watercourse
conditions Such as hyd0|OViC patterns/flow ngteS`
Sin83m grGdi8nt, bank full width. stream bed
conditions, bank conditions, fish and other wildlife use,
in -stream 5tnuC(ur8S. riparian COndiUOnS. buffer
ohansctehndos, water quality, fish barriers and other
relevant information.
|i Environmental goals and objectives that describe the purposes of the mitigation measures. This
should include a description of site selection criteria, identification of tarqet evaluation species and functions.
iii Performance standards for fu|fiUiDq8Ovi' 0nnOent@|V0G|Sand objectives and for thqq8hngremedial
action nronnUnOenoymeasures. Performance standards may include water quality st3nd8rdn, species richness
and diversity tarqets, habitat diversity indices, creation of fish habitat, or other ecological, qeoloqical or hVdroloqical
criteria.
iv. Detailed construction plan of the written specifications and descriptions of mitigation techniques.
This plan should include the proposed construction sequence and construction manaqement, and be accompanied
by detailed site dia0rams and blueprints that are an inhoqra| requirement 0fany development proposal.
v. Monitorinq and/or evaluation proqram that outlines the approach for assessinq a completed project.
At least five years OfmOOih3hRqi5required, Anoutline shall b8included that spells out how the nOOni0Jhnqdata will
beevaluated byaqencieothat ar8traokinq the miUqaUnn0rOi8ct'sprocess. For projects that disoh8nlesk)rmw80ar
to 8 St/88m. the Director may require water quality nO0nih]hnV.
vi CnndnqSnCy plan id9ndfyinq pO0Snd8| COurS8S of action and any corrective measures to be t9h8O
when monitorinq or evaluation indicates project performance standards have not been met.
vii Performance security or other assurance devices as described in TIVIC Section 18.45.210.
(Ord, 2301§1(pa/d 20y0)
18.45.100 Areas of Potential Geologic Instability Designation, Rating and Buffers
A. DESIGNATION — Potential areas nfqeo|O0iC instability include om3S of potential omSiUn and landslide
hazards. Areas of potential g8O|OgiC instability are d8SSifi8d as h)UOwS:
1. C|8SS 1 area, where landslide potential is low, and which has 3slope Ofsless than 15%;
2. C|8SS 2 8r88S. where landslide potential is mndnnehe, which has o slope is between 15% and 40%.
Page 27 of 42
and which are underlain by relatively permeable SOUS;
3. C|88S 3 8re8S. where landslide potential is high, which include areas sloping between 15% and
40%, and which are underlain by relatively impermeable soils or by bedrock, and which also include all areas sloping
more steeply than 4O%;
4�—C|8SS4areas, which include sloping areas with mappable zones
of groundwater S8Op8g8' and which also include existing 08ppUb|O |3DdS|idO deposits regardless OfS|Opaj
��appiOq.
1. The approximate location, extent, and desiqnation of areas of potential qeoloqic instability are depicted
inthe City'sCritical Areas Map. Actual boundaries and deniqnadnnsshall bedetermined byaqualified professional on
asite-specific basis.
2. In addition to the Qty'SCritical Areas Map, the followinq publicly available mGppinqinformation may be
used 0odetermine appropriate designations:
o. For historic landslides, areas dnniqnatndosquaternary slumps, oarthOown mudOows.orlandslides onmaps
pub|iShSdbyUl8U.8.GedOgiC8|GumeyOr8l8VVONROiviSiOnnfG8O|Ogy8ndE8rthReSOurc8Si
b� For potential or historic landslides, those areas mapped by the WDNR (slope stability mappinq) as unstable (U or
o|onn 3), unstable old slides (UOG orclass 4). or unstable recent slides /URG or class 5\;
c. For soil characteristics, the U.S. Department of Aqriculture's Natural Resources Conservation Service (NRCS)
Official Soil Survey Data; and
d� For qen8r8|instability, those areas mapped bythe NRCSaSh8vinq aSiOnifiC8n1limitation for bui|dinqsite
development.
C� 8UFFE08-
571. The buffers for GrS8S Of potential g8O|OgiC instability are intended to:
a. Minimize long-term impacts of development on properties containing sensitive areacritical areas;
b. Protect Sf**&&-f�8CridC8|areas from adverse impacts during development;
C. Prevent loading of potentially unstable S|Op8 f0r08U0nS;
d. Protect slope stability;
H. Provide erosion control and attenuation 0fpre- ciDdatioOsurface water and stOrDw8te[runoff; and
[ Reduce loss ofOrdamage U}property.
6. An undisturbed sensitive area or buffer may substitute for the yard s9UJ@Ck and landscape requirements of
development proposal containing O[threatened bv GOarea 0f potential geologic instability Class 20[
higher shall be subject to 8 geVteChnic8| report pursuant to the requirements Of TMC Chapter 18.45.040 C' and
1845.060. The geot8chnic8| report shall analyze and make recommendations on the need for and width of any
setbacks or buffers necessary 1Oachieve the gO8|S and [8qui[8m8OtS Of thiS Ch3p t e[TyNC Chapter 18.45.
Development proposals shall then include the buffer distances 3Gdefined within the g8O03chniS8|report.
G-.E.Buffem may bnincreased by the Director when an area is determined to be particularly SCnCidvC to the
disturbance created by a development. Such a decision will be based on a City review of the report as prepared
/OrdJ388§40 20/21,Ord. Z301§1 (part), 2010
18.45.130 Areas ofPotential Geologic Instability Uses, Exemptions, Alterations and Mitigation.
A. GENERAL —The uS8S permitted in the underlying zoning district may be undertaken OO sites that DOOt8iO
8rH8S Of potential g8O|OgiC instability subject to the standards of this section and the nBCOmmend8UOnS of
g8008ChOiC8|S1udy.
B. EXEMPTIONS — The following areas are exempt from regulation aageologically hazardous areas:
1. Temporary stockpiles of topsoil, gnGv8|, beauty bark Urother similar landscaping or construction
03t8h8|S�
'
2. G|OpeS related to m8t8h8|S used as an engineered pre -load for a building pad;
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Page 28 of 42
permit may be ro graded without application of TMC Chapter 18.45 under an approved permit;
43_Roadway embankments within right-of-way or road easements; and
5.1. Slopes retained by approved engineered structures.
C. ALTERATIONS-
1. Prior to permitting alteration of an area of potential geologic instability, the applicant must
demonstrate one of the following:
a. There is no evidence of past instability or earth movement in the vicinity of the proposed
development, and where appropriate, quantitative analysis of slope stability indicates no significant risk to the
proposed development or surrounding properties; or
b. The area of potential geologic instability can be modified or the project can be designed so
that any potential impact to the project and surrounding properties is eliminated, slope stability is not decreased,
and the increase in surface water discharge or sedimentation shall not decrease slope stability.
2. Where any portion of an area of potential geologic instability is cleared for development, a landscaping
plan for the site shall include tree replanting with an equal mix of evergreen and deciduous trees, shrubs and
groundcovers, preferably native, and approved by the Director. Replacement vegetation shall be sufficient to provide
erosion and stabilization protection.
3. Critical facilities shall not be sited within or below an area of potential geologic instability unless
there is no practical alternative (demonstrated by the applicant)
4. Land disturbing activities in an area of potential geologic instability shall provide for storm water
quality and quantity control, including preparation of a TESC and permanent drainage plan prepared by a
professional engineer licensed in WA.
5. Unless otherwise provided or as part of an approved alteration, removal of vegetation from an area
of potential geologic instability or its buffer shall be prohibited. When permitted as part of an approved alteration,
vegetation removal shall be minimized to the extent practicable
6. Surface drainage, including downspouts, shall not be directed across the face of an area of
potential geologic instability; if drainage must be discharged from the top of a hazard to its toe, it shall be collected
above the top and directed to the toe by tight line drain, and provided with an energy dissipative device at the toe for
discharge to a swale or other acceptable natural drainage areas
7. Structures and improvements shall minimize alterations to the natural contour of the slope, and
foundations shall be tiered where possible to conform to existing topography (minimize grading/cut & fill to amount
necessary)
The proposed development shall not result in greater risk or a need for increased buffers on neighboring properties
D. DISCLOSURES, DECLARATIONS AND COVENANTS
1. It shall be the responsibility of the applicant to submit, consistent with the findings of the
geotechnical report, structural plans that were prepared and stamped by a structural engineer. The plans and
specifications shall be accompanied by a letter from the geotechnical engineer who prepared the geotechnical
report stating that in his/her judgment the plans and specifications conform to the recommendations in the
geotechnical report, the risk of damage to the proposed development site from soil instability will be minimal
subject to the conditions set forth in the report, and the proposed development will not increase the potential for
soil movement.
2. Further recommendations signed and sealed by the geotechnical engineer shall be provided should
there be additions or exceptions to the original recommendations based on the plans,
site conditions or other supporting data. If the geotechnical engineerwho reviews the plans and specifications is not
the same engineerwho prepared the geotechnical report, the new engineer shall, in a letter to the City accompanying
the plans and specifications, express his or her agreement or disagreement with the recommendations in the
geotechnical report and state that the plans and specifications conform to his or her recommendations.
3. The architect or structural engineer shall submit to the City, with the plans and specifications, a letter
or notation on the design drawings at the time of permit application stating that he or she has reviewed the
geotechnical report, understands its recommendations, has explained or has had explained to the owner the
Page 29 of 42
risks of loss due to slides on the site, and has incorporated into the design the recommendations of the report and
established measures to reduce the potential risk of injury or damage that might be caused by any earth movement
predicted in the report.
4. The owner shall execute a Sensitive Ar aCritical Areas Covenant and Hold Harmless Agreement
running with the land on a form provided by the City. The City will file the completed covenant with the King County
Department of Records and Elections at the expense of the applicant or owner. A copy of the recorded covenant will
be forwarded to the owner.
E. ASSURANCE DEVICES — Whenever the City determines that the public interest would not be served
by the issuance of a permit in an area of potential geologic instability without assurance of a means of providing
for restoration of areas disturbed by, and repair of property damage caused by, slides arising out of or occurring
during construction, the Director may require assurance devices pursuant to TMC Section 18.45.210.
F. CONSTRUCTION MONITORING —
1. Where recommended by the geotechnical report, the applicant shall retain a geotechnical engineer to
monitor the site during construction. The applicant shall preferably retain the geotechnical engineer who prepared
the final geotechnical recommendations and reviewed the plans and specifications. If a different geotechnical
engineer is retained by the owner, the new geotechnical engineer shall submit a letter to the City stating whether
or not he/she agrees with the opinions and recommendations of the original geotechnical engineer. Further
recommendations, signed and sealed by the geotechnical engineer, and supporting data shall be provided should
there be exceptions to the original recommendations.
2. The geotechnical engineer shall monitor, during construction, compliance with the recommendations
in the geotechnical report, particularly site excavation, shoring, soil support for foundations including piles,
subdrainage installations, soil compaction and any other geotechnical aspects of the construction. Unless
otherwise approved by the City, the specific recommendations contained in the soils report must be implemented
by the owner. The geotechnical engineer shall make written, dated monitoring reports on the progress of the
construction to the City at such timely intervals as shall be specified. Omissions or deviations from the
approved plans and specifications shall be immediately reported to the City. The final construction monitoring
report shall contain a statement from the geotechnical engineer that based upon his or her professional opinion,
site observations and testing during the monitoring of the construction, the completed development substantially
complies with the recommendations in the geotechnical report and with all geotechnical-related permit
requirements. Occupancy of the project will not be approved until the report has been reviewed and accepted by the
Director.
G. CONDITIONING AND DENIAL OF USE OR DEVELOPMENTS-
1. Substantial weight shall be given to ensuring continued slope stability and the resulting public health,
safety and welfare in determining whether a development should be allowed.
2. The City may impose conditions that address site- work problems which could include, but are not
limited to, limiting all excavation and drainage installation to the dryer season, or sequencing activities such as
installing erosion control and drainage systems well in advance of construction. A permit will be denied if it is
determined by the Director that the development will increase the potential of soil movement that results in an
unacceptable risk of damage to the proposed development, its site or adjacent properties.
(Ord. 2301 §1(art), 2010)
18.45.140 CooIMine Hazard Areas
A. Development of a site containing an abandoned mine area may be permitted when a geotechnical
report shows that significant risks associated with the abandoned mine workings can be eliminated or mitigated so
that the site is safe. Approval shall be obtained from the Director before any building or land -altering permit
processes begin.
B. Any building setback or land alteration shall be based on the geotechnical report.
C. The City may impose conditions that address site -work problems which could include, but are not limited
to, limiting all excavation and drainage installation to the dryer season, or sequencing activities such as installing
drainage systems or erosion controls well in advance of construction. A permit will be denied if it is determined
that the development will increase the potential of soil movement or result in an unacceptable risk of damage
75
Page 30 of 42
to the proposed development or adjacent properties.
D. The owner shall execute 8Sensitive AneaChU[@|Areas Covenant and Hold Harmless Agreement running
with the land OO8form provided by the City. The City will file the completed covenant with the King County Division
{fRecords and Elections atthe expense 0fthe applicant O[owner. Acopy 0fthe recorded covenant will b8forwarded
k)the owner.
18.45.150 Fish and Wildlife Habitat Conservation Areas Designation, Mapping, Uses and
Standards
A, DESIGNATION —
1. Fish and wildlife habitat conservation areas include the habitats listed below:
8. Areas with which endangered, threatened, and sensitive species have 8primary association;
b. Habitats and species of local importance, including but not limited to bald eagle habitat, heron rookeries, mudflats and
marshes, and areas critical for habitat connectivity;
o. Commercial and recreational shellfish or s;
c. Mudfzband n
marshes;
rallyoccurring ponds under 20acres and their submerged aquatic beds that provide fish 0rwildlife habitat;
ed. Waters 0fthe State;
o. State natural area preserves and natural nas0umo conservation areas; and
h-.f.LakeS. 00ndS. Str8GmS. and rivers planted with qame fish by3 governmental or tribal entity
i Areas critical for habitat connectivity,
2. Ty0GOwatercourses, indudin0the Green8}uwgmiShRiver, are reOu|at8dunder TIVIC1O.44and not under this
section,
3. Wetlands and watercourses are addressed under 1R.45DOO.1O.45D9O.10.45100and 18.45]10.and not under
this section.
B. MAPPING —
1. The approximate location and extent of known fish and wildlife habitat conservation areas are identified
by the Cih/3 SencitivoAo oChdCa|Areas Maps, inventories, open space zones, and Natural Environment Background
Report. The City deSigRates 1, 2, 5, 6, 7, and 9 above as kRewn fish and wildlife hab.tats withiR its GuFFeRt limits.
2. Fish and wildlife habitat GGRSewafion aFeas Gerrelate Glesely will, the areas identified as regulated
watercourses and wetlands and their buffers inTukwila. The Gr9en/Duw0mi:hRiver is recognized GS the most
significant fish and wildlife habitat corridor, oswell asoff-channel habitat areas created inthe river 0o improve salmon.
habitat (shown on the Sensitive Areas K4op) in the Shoreline jurisdiction, Gilliam CrCCk, Riverton Crock, Southgate
Greek, johnsen CFeek, and Hamm GFeek (IR the ROrth PAA) all provide salmenid habitat. IR addition, the Native
GMWth PF9t8Gti9n Area 'R the Tukwila South prGjeGt area pFevides aR impertaRt upland wildlife habitat GeFridor.
Tukwila Pond and its associated wetlands AOmeet the definition OfGfish and wildlife habitat for waterfowl and
other birds during all seasons nfthe year. |naddition h3the GencidveAnezCriUCa|areas Maps, the following maps are
to be used as 3 guide for the City, but do not provide @ fiO8| habitat area d8GigO8U0O:
@. VV8ShiOgtOO State Department 0fFish and Wildlife PhOhh/ Habitat and Species K48pS;
b. An8d0mOU3 and resident S3|mOnid distribution maps contained in the Habitat Limiting Factors
reports for the Green/Duwamish and Central Puqet Sound Watersheds published by Kinq CountV and the Washington
Conservation Commission; and
Washington StatoNOAA Digital Coastal for Washington 8tateond Coastal Zone Management Program.
C. BUFFERS --
1. Each development proposal on, adiacent to, or with the potential to impact a Fish and Wildlife Habitat
Conservation Areas shall have buffers no less than 100 feet in width, s other than wetlands and watercourses shall
bBsubject h]ahabitat assessment report pursuant 03the requirements ofTK4CChapter 18.45.O4O.Band
10.45,O00,The habitat assessment shall Gn8|yz8and make recommendations 0nthe need for and width Ofeny
setbacks Or buffers neCe5SGrytU achieve the O08|S and requirements of this chapter, with specific consideration of
PhOhtyHabitats and Species M8n8qomentRecommendations from the VV33hinOk)nDepartment ofFish and
Page 31 of 42
Wildlife, Recommended bshaUhave buffers shall beOOless than 1OOfeet inwidth.-
1 . Buffer reductions approved for onunderlying wetland orwatercourse shall also apply hathe related
Conservation Area.
2. Buffers may boincreased bythe Director when onarea isdetermined 0obe particularly sensitive Uo
the disturbance created byadevelopment. Such gdecision will b8based 0n8City review Ofthe report 8S
prepared byaqualified bio|oqistand byasite visit.
A—.D. USES AND STANDARDS Fish and wildlife habitat conservation areas will be regulated
related 0owetlands and watercourses. No additional use regulations apply specifically hnConservation
Areas. Each development proposal on, adjacent, Orwith the potential k)impact a Fish and Wildlife Habitat
Conservation Area that isnot fully addressed under 1045.O8U.1945,O9O.1O.451OOand 1845.11Oshall be
subject tV8habitat assessment report pursuant 0Jthe requirements OfTK8CChapter 1845.040.Band 18.45.O5O.
The habitat assessment shall analyze potential impacts to Fish and Wildlife Habitat Conservation Areas and make
recommendations to minimize such impacts, with specific consideration of Priority Habitats and Species
Manaq8ment Recommendations from the VV8Shinq0Jn Department 0fFish and Wildlife.
(]ni230Y§/(panV' 2010)
18.45.155 Special Hazard Flood Areas
A. Rqu|8UODS governing Special Hazard Flood areas are found in TK8C Chapter 10.52, HOUd Z0O8
K88naqSmSnLand 1845.155.B.
B. Floodplain Habitat Assessment.
1. When development is proposed within a Special Hazard Flood areas-, a floodplain habitat assessment
shall bnprepared pursuant hothe requirements ofTK4CChapter 10.45.040Band 18.45.08O.
2. The flondp|ainhabitat assessment shall address the effects ofthe development nnfederally listed salmon,
incluUinq, but not limited 03the fn||owinq:
8. Impervious surfaces,
U. F|0odp|8inshoraq9and conveyance,
C. F|ondp|ainand riparian veqotgUOn.and
d. Gto,mwo0erdn8inage
3 |fthe OoOdp|ainhabitat assessment concludes that the project isexpected 0rhave anadverse effect On
listed Sp8deS as 8v8|u818d under the 0uid8Oc8 issued for ESA Cnmp|i@OCS under the National Flood
Insurance PmOngm in Puq8tG0und. the applicant shall miUq8tethVsn impacts. Such mitigation shall be
consistent with, or in addition to, any mitigation required by this Chapter and shall be incorporated into
the approved project p|8OS.
4. Activities Exempt from F|oOdp|8iOHabitat Assessment. AflOVdp|8inhabitat assessment iSnot required
under the foUUwinqcircumstances:
8. Projects that are underqoinq or have underqone consultation with the National Marine Fisheries
Service under the End8nq8n8dSpecies Act,
b. Repair or namodo|inq of on exisUnq siruoLunB. if the repair or [emUdS|iOq is not 8 substantial
improvement.
c. Expansion OfanmdStinOstructure that isnoqreoterthan 1Dpercent beyond its existing footprint
provided, that the repairs Or r8m0dH|inq is not 8 substantial i0p0vSnO9nt. Or 8 repair Of
SubShanh8| d8maQo. This measurement iScounted cumulatively from September22. 2011. If
77
Page 32 of 42
the structure is in theflnodwoy. Ulmno shall be no change in the dimensions perpendicular to
flow.
d. Activities with the SO|S puU)O88 OfCr8adnO. rSnk}hn0. Orenh8nCinO natural fVnoUOnS provided
the activities do not include construction of structures, gradinq, fill, or impervious surfaces.
8. Development ofopen space and recreational fac|hies, such as parks and trails, that do not
include stnJctUr8S, fill, impervious SVdaCe3 or removal of more than 5 percent of the native
veqetaUonnnthat portion ofthe property inthe mqu|o1oryflnodp|ain.
f, Repair to on -site septic systems provided the qround disturbance is the minimum necessary,
q. Other minor activities considered to have no effect on listed speoics, as interpreted using EGA
quidanC8 iSSV8d by the National Flood |nSUr3nCS PrOqn8m in Puget Sound and confirmed
th0uqhCity review Ofthe development proposal.
A. Purpose, Objectives and Applicability.
13hepurpOse of this section is to:
3. RROu|atB the protection Vfe«istinU trees and native veqetgU0n in the ChUC8| 8r88S and their buffers;
b. Establish requirements for removal of invasive plants at the time of development or re -development of sites;
c. Establish requirements for the lonq-term maintenance of native vegetation to prevent establishment of invasive
species and promote ecosystem processes.
B. VegetationRetention and Replacement.
1. The tree protection and retention requirements and the vGq9iGdOn manG0emerU requirements 800|y N
existing uses as well 8Snew Orre-d8v8|OVm9OL
2. NadveveqotBUOn in oriUCo| 8m@s and their buffers must be prn0ooh9d and maintained. No removal of
native veq8C8tiOOiSallowed without prior approval bythe City except incases 0f809[q8nCywhere 8Oimminent
hazard to public life, safety or property exists. Veqetation may be removed from the buffer as part of an
8Oh8nQ8m8Ot plan approved by the Director, Enhancements will ensure that slope stability and wetland quality will
be maintained or improved. Any temporary disturbance of the buffers shall be replanted with a diverse plant
community Ofnative northwest species.
3. Invasive veqetation (blackberry, ivy, laurel, etc.) may be removed from a critical area or its buffer except steep
slopes without a permit ifremoval does not utilize heavy equipment Orherbicide. Invasive v8qet8Uonremoval Vnsteep
slopes requires prior City Approval
4. Hazan]0usUrdefectivetreos.oSdofinodinTMC18.O8.moyb9remnvodfrnmoohdCa|areaifthneot posed
by the tree is imminent. If the hazard is not obvious, an assessment by 8 certified pmfeS3iono|, as defined in TMC
18.06, may be required by the Director. Dead and hazardous trees should remain standinq or be cut and placed within
the critical area 03the extent practicable to maximize habitat. Tree replacement in accordance with this chapter iS
required for any hazardous tree removed from acritical area.
s. In the C8S8 0fdevelopment n[n8'd8v9|0pnleOt. as 08Oy SiqOifiC3n\tn38S and as much native vegetation 83
possible are to be retained on a site, takinq into account the condition and age of the trees. Aspart ofproject review,
the Director of Community Development or the Board of Architectural Review may require alterations in the
arrangement of buildings, parkinq or other elements of proposed development in order to retain significant veqetation.
Page 33 of 42
a To protect the ecological functions that troon, and native veOmtadon provide to chdua| ameo, removal of any
siqnificant tree or native veqetation in a critical area or its buffer requires a Critical Area Tree Removal and Vegetation
Clearing Permit and is generally only allowed on sites undanloinq development nrm'deve|oRmonL Only trees that
interfere with access and passaqe on public trails or trees that present an imminent hazard to existinq structures or the
public may beremoved from sites without 8nissued bui|dinqpermit nrFederal approval. Factors that will b8considered
in3pprOvinOtree removal include but are not limited to: tree condition and health, 8O8.risks k}structures, and potential
for root or canopy interference with utilities.
7.Phor03any hazardous tree removal {xsite nleahn0unless it is part OfSpecial Permission approval for interrupted
buffer, buffer averaginq or other critical areas deviation, a Type 2 Critical Area Tree Removal and Vegetation Clearinq
Permit application mUS\ be submitted to the Department of Community Development (DCD) COnt8ininq the f0||Ovvinq
information:
a. Av8qetaUVn survey On a site 0|8n that shows the diameter, 3ped8S and |0Q8U0n of all 3i0nific8nt trees and all
existing native vnqetabon.
lb� A site plan that shows trees and native vegetation to be retained and trees to be removed and provides a table
showing the number of significant trees to be removed and the number of replacement trees required.
cTree protection zones and other measures tnprotect any trees nrnative vegetation that are tobmretained for
sites und8nl0in0development 0rre'U8ve|0pmSnt.
d, Location of the OHWM, stream buffer, wetland, wetland buffer, steep slope or any other critical areas with their
buffers.
9. A landscape plan that shows diameter, species name, Sp@CnO and pl8nbn0 location for any required
replacement trees and other proposed veqetadon.
f. An arborist evaluation justifyinq the removal of hazardous trees if required by DCD.
q.Anapplication fee per the current Land Use Permit Fee resolution.
O.VVhere permittmd, siVnifioonttnpon that are removed from nridon| areas ahoU be replaced pursuant to the tree
r9p|8C8m8ni requirements shown be|mw, uVk]g density Of10Otrees per acre (inC|udin0 8xiSUn0tn88S). The Director
may require additional trees or shrubs to be installed to mitigate any potential impact from the |nnn of this vegetation
aSaresult Ofnew development.
—
Tree Replacement Requirements
Diameter* ofTree Removed (°meosured
Number of
Replacement Trees
etheightof4.5feet from the qmund)
Required
40inches (oinq|ehunk);
2inches (any trunk ofamulti-trunk tma)
3
Over 6'Dinches
4'
Over 8'2Oinches
6'
Over 20inches
K
9.The property owner is required 0nensure the viability and lonq-tonnhealth nf vegetation planted for replacement
or mitiqation throuqh proper care and maintenance for the life of the project Mitiqation or restoration projects1h81f8i|
to meet pre -determined performance standards must be replanted in the next appropriate season fO[p|GndOq or per
requirements Ofapproved K8iticl8UOnPlan.
10, If all required replacement trees cannot be reasonably accommodated on the site, the applicant shall pay into
atree replacement fund. The fee shall b8determined Onanannual basis 8spart ofthe Fee resolution.
11.DeadOrdyiOq trees located within 80fGcritical area 0[its buffer shall b8left iDplace 8Swildlife snags, unless
they present o hazard to stmotums, facilities or the public. Dead or dyinq trees within developed or landscaped
areas shall boreplaced 1:1 inthe next appropriate season for 0|andnq.
12TOpping of trees is prohibited and will be regulated as [8mOv8| with tree replacement required,
13.P[UOiOq0ftrees shall not exceed 25%Vfcanopy iOathree year period. P0OiOqiOexcess Of25%canopy shall
be /8qu|ated as removal with tree replacement required. Trees may only be pruned to lower their h8iqhtt0 prevent
79
Page 34 of 42
interference with onoverhead utility line with prior approval bythe Director aspart ofType 2Critical Area Tree Permit.
The pruning must becarried out under the direction Of8Qualified Tree Professional 0rperfnnn8dby1heud|ityprOvide[
under the direction of a Qualified Tree Professional. The crown shall be maintained to at least 2/3the height ofthe tree
prior to pruning.
C.Tree Protection
All trees not proposed for removal aspart 0f8project Ord8v8|OpmentShaUb6proteCtedVSinVBest Management
Practices and the standards below.
1. The Critical Root Zones (CRZ) for all trees designated for retention, on site or on adjacent property aSapplicable,
shall b8identified Onall construction plans, including demolition, grading, civil and landscape site plans.
2. Any roots within the CRZ exposed during construction shall be covered immediately and kept moist with
appropriate materials. The City may require athird-party Qualified Tree Professional tOreview long-term viability Ofthe
tree.
5. Physical b8ni8rS. such as 6-foot chain link fence or plywood 0rother approved equivalent, shall be placed
around each individual tree or grouping at the CRZ.
4. Minimum distances from the trunk for the physical barriers shall be based on the approximate age of the tree
(height and canopy) 3Sfollows:
e. Young trees (trees which have reached less than20% of life expectancy):O.75 per inch of trunk diameter.
b.Mature trees (trees which have reached 2O-80%Uflife exp8ct8ncv:1foot per inch Oftrunk diameter.
c. Over mature trees (trees which have reached greater than 80% of life expectancy): 1,5 feet per inch oftrunk
diameter.
5. Alternative protection methods may be used that provide equal Or greater tree protection if approved by the
Director,
0.Aweatherproof sign shall bSinstalled Onthe fence Vrbarrier that reads:
"TREE PROTECTION ZONE — THIS FENCE SHALL NOT BE REMOVED OR ENCROACHED UPON. NV soil
disturbonno, padking, stomqe, dumping or burning of materials is allowed within the Chdoa| Root Zone. The value of
this tnB8 is $ [insert value Of 1n8e as determined by a Qualified Tree Professional here]. Damage to this tree due to
construction activity that results in the death or necessary mmnvo| of the tree is subject to the Violations section of
TMC Chapter 18.45.^
7. All tree protection measures installed shall be inspected by the City and, if deemed necessary a Qualified Tree
Professional, prior tobeOinninOconstruction nrearth m0vinq.
M. Any branches or |inlbS that are outside of the CRZ and might be damaged by nl8ChiO8ry Sho|| be pruned phO[
to construction byaQualified Tree Professional.
the direct supervision Qf3Qualified Tree Professional,
9.The CRZ shall becovered with 4hoOinches Vfwood chip mulch. Mulch shall not beplaced directly oqainst the
trunk. A6'inCharea around the trunk shall b8free 0fmulch. Additional measures, such GSfertilization O[supplemental
wG03,, oh8|| be Ca[h9d Out prior to the StGd of construction if deemed neC8SS8[y by the Qualified Tree P0fSSsiOOG[s
report 0nprepare the trees for the stress Ufconstruction activities.
10. No storage of equipment or refuse, parking of vehicles, dumping of m8teh3|S or Che0icG|n. or placement Of
permanent heavy structures Vritems shall occur within the CRZ.
11. No grade changes or soil disturbance, including trenching, shall be allowed within the CRZ. Grade changes
within 1Ofeet Ofthe CRZ shall beapproved bythe City prior klimplementation.
12. The applicant is responsible for ensurinq that the CRZ of trees on adjacent properties are not impacted bythe
proposed development,
13. A pre -construction inspection shall be conducted by the City to finalize tree protection actions.
14, POst'COnSt0C1i0D inspection of protected trees Sh8|| be conducted by the City and, if deemed necessary by
the City. a Qualified Tn98 Professional. All corrective or reparative pruninqvviU be conducted bye Qualified Tree
Professional.
Page 35 of 42
D. Plant Materials Standards
For any new development, redevelopment Or n8stOn8Uon in 8 ChUc8| Area, invasive vegetation must
be removed, and native vegetation planted and maintained in the Critical Area and its buffer.
1. A p|@nUnq plan prepared by 8 qualified biologist 8hG|| be submitted to the City for approval that shows plant
SpHci8S, siz8, number, sp@cing, nui| preparation iRiq3UoO. and invasive ep8oi8S n300vai The requirement for
a bioloqist may be waived by the Director for single family property owners when the mitigation area is less than 1500
2. Invasive voqetadVn must be removed as part of site preparation and native veqetaUon planted in the Chdoa|
Area and its buffer where impacts occur.
I. Removal of invasive species shall be done by hand or with hand-held power tools. VVhom not feasible and
mechanized equipment in nendad, the applicant must obtain o Type 2 permit prior 0zwork being conducted. Removal
of invasive vegetation must be conducted SV that the slope Si8bi|ih/, if applicable, will be maintained. Ap|8n must be
submitted indicaUnq how the work will be done and what erosion onntm| and tnao protection features will be
utilized. Federal and State permits may be required for vegetation removal with mechanized equipment.
4, Removal of invasive vegetation may be phased over several years prior to plantinq, if such phasing is provided
for by G plan approved by the Director to 8UVw for 3|iBrn8Uv8 8ppn]3CheS. such as Sheet mulching and qO8t
qnRzinq. The method selected shall not destabilize the bank 0rcause erosion.
5, Aoombinadon of native trems, shrubs and gmundoovors (including but not limited to gra5sen, sedges, rushes
and vines) shall be planted. Site C0ndi1iOnS, such as b3pOqn8phy. exposure, and hyd0|Oqy shall be taken into
account for plant selection. Other species may be approved if there is adequate justification,
6'Non'n3Uve trees may b8used @Sstreet trees incases where conditions are not appropriate for native trees (for
example where there are space 0rh8iqhilimitations 0rconflicts with u0iU8S).
7.P|ants shall meet the current American Standard for Nursery Stock (American Nursery and Landscape
Association —ANLAj.
O. Smaller plant sizes (generally one ga||on, bmroroot, p|ugs, or stakes, depending on plant species) are preferred
for buffer p|anUn0S. VYi||Vw St8k8S must be at |9@St 1/2-inch in diameter. For exiSUnq Uev8|O03d areas refer 10
landscaping chapter TK8C18.52for plant sizes inrequired landscape areas.
9. Site preparation and plantinq of veqetation shall be in accordance with best manaqement practices for ensurinq
the veqGt@dOn'Slong-term health and survival. |rrigGUUniSrequired for all plantings for the first three years GSapproved
by the Director.
10. P|8OtS may be selected and p|Go8d to allow for public and private view corridors with approval by Director.
11. Native veqetation in Critical Areas and their buffers installed in accordance with the precedinq standards shall
be maintained by the property owner to promote healthy qmwth and prevent establishment of invasive
S0eCi8S. Invasive plants (such 8Sblackberry, ivy, k000w8ed.bindweed) shall beremoved OO8regular basis, 8CCO[ding
to the approved maintenance plan.
12.Critical Areas inc|udinq steep slopes disturbed byremoval Ofinvasive plants Ordevelopment shall bSreplanted
with native veqotaUon where necessary to maintain the density shown in Table below. and must be replanted in o
timely 08On8[. 8xCB0t vvh8[8 8|Onq'te[nlremoval and re -vegetation plan, GS GVp0w8U by the Ci1y, is being
implemented.
Critical Area Buffer Vegetation Planting Densities Table
Plant Material Type
Planting Density
Stakeo/cuttinqn amnq
1 2 feet oncenter orper
nUaombank (wiUown, red osierbioonqineerinqme\hod
dogwood)
Shrubs
3 5feet oncenter, dapendinq
on species
Trees
15-2Ufeet uncenter,
Oapondinqonspecies
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Page 36 of 42
Gmundouvers. qramono. 1-1.5feet nncenter,
smdqes, mohes, other herbaceous
plants
dependinq on species
Native seed mixes
5-25|�. per acre, dependinq
on species
15Th8 Department Director, in COnSuU3U0n with the City'5 environmentalist, may approve the use of shrub
planting and installation ofwillow stakes tobocounted toward the tree replacement standard inthe buffer if proposed
aS8measure tUcontrol invasive plants and increase buffer function.
E. VgOgtgUon Management in ChhcG| Areas The requirements of this S8CUVn apply to all 8xiSUnq and new
development within critical areas.
1.Trees and shrubs may only be pruned for safety, to maintain access corridors and trails by pruninq up or on the
sides of trees, to maintain clearance for utility lines, and/or for improving shoreline ecoloqical function. No more
than 2596may b8pruned from a tree within 338month period without prior City review. This type Of00ninOiSexempt
from any permit requirements.
2.Plant debris from removal of invasive plants or pruning shall be removed from the site and disposed of properly
unless nnsite StOr8qSiSapproved hythe Director.
3.Usnofpesticides.
a. Po3UCiUeS (indudinq h9rbiCid8S, inS8CdCid8a. and fungicides) shall not be used inthe critical area Vrits buffer
except where:
/1) Alternatives such as manual namuvei bio|oOico| oontm|, and cultural control are not feasible given the size of
the infestation, site characteristics, 0rthe characteristics Ofthe invasive plant species;
(2) The use of pesticides has been approved by the City through a comprehensive vegetation or pest management
and monitoring plan;
(5)The pesticide isapplied inaccordance with state regulations;
(4)The proposed herbicide is approved for aquatic use by the U.S. Environmental Protection Agency; and
(5) The use of pesticides in the shoreline jurisdiction is approved in writinq by the City and the applicant presents
a copy of the Aquatic Pesticide Permit issued by the Department of Ecoloqy or Washinqton Department of Aqriculture.
b.Self-contained rodent bait boxes U8SiqOedtOprevent access byother animals are allowed.
C. Sports fields, p8rhs. On|foouroos and other outdoor recreational uses that involve maintenance of extensive
8n88S Ufturf shall implement an in0SqnBted turf 03n8qe0Snt p0qnG0 or integrated pest management plan designed
to ensure that water quality inthe Critical Area iSnot adversely impacted.
4.Roxh}rGtion PmiootP|8ndnqn: RoShon]UUn projects may ovorV|ant the site as a way to discourage the re-
establishment of invasive species. Thinninq of veqetation without a separate Type 2 Special Permission or critical area
tree permit may be permitted five to ten years after p|8nUnq if this approach is approved as part of the restoration
p0i8[1'S nlaiOt8n8nC8 and 0VOitOhOV p|oD and with approval by the City prior to thiOOiOq work.
F. Maintenance and Monitoring.
1. Afive-year mOnih3hOqand maintenance plan must b8approved bythe City prior t0permit issuance. The
monitoring period will beqin when the restoration is accepted by the City and as -built plans have been submitted.
2. Monitoring reports shall be submitted annually for City review up Vnd| the end Of the monitoring
period. Reports shall m88sVm survival rates oq3in31 project qOa|S and present DonUnq9nnyplans h} meet project
gVo|3.
3. Mitigation will becomplete after project goals have been met and accepted by the City environmentalist,
4. Aperformance bond or financial security equal N 150% Of the cost Of labor and mat8hJ|3 required
for implementation of the plantinq, maintenance and monitorinq shall be submitted prior to City acceptance of project.
Page 37 of 42
18.45.160 Critical Area Master Plan Overlay
A. The purpose of this section is to provide an alternative to preservation of existing individual wetlands,
watercourses and their buffers in situations where an area -wide plan for alteration and mitigation will result in
improvements to water quality, fish and wildlife habitat and hydrology beyond those that would occur through
the strict application of the provisions of TMC Chapter 18.45.
B. The City Council may designate certain areas as 'ffve A Critical Area Master Plan Overlay Districts
for the purpose of allowing and encouraging a comprehensive approach to sensitive areacritical area protection,
restoration, enhancement and creation in appropriate circumstances utilizing best available science. Designation of
Se t AreaCritical Area Master Plan Overlay Districts shall occur through the Type 5 decision process
established by TMC Chapter 18.104.
C. Criteria for designating a Sensitive AreaCritical Area Master Plan Overlay District shall be as follows:
1. The overlay area shall be at least 10 acres.
2. The City Council shall -find that preparation and implementation of a e�Critical Aea Master
Plan is likely to result in net improvements in sensitive areacritical area functions when compared to development
under the general provisions of TMC Chapter 18.45.
D. Within a Sensitive AreaCritical Area Master Plan Overlay District, only those uses permitted under TMC
Sections 18.45.070, 18.45.090 and 18.45.110 shall be allowed within a Category I wetland, a Type 1 (S)
watercourse, or their its buffers.
E. Within a ®teeitive pie Critical Area Master Plan Overlay district, the uses permitted under TMC 18.45.070,
18.45.090 and 18.45.110 and other uses as identified by an approved S Critical Area Master Plan shall
be permitted within Category III and Category IV wetlands and their buffers; and within Typed {FL-3-{Npl) and 4
{Ns) watercourses and their buffers, provided that such uses are allowed by the underlying zoning designation.
F. A Sensitive Ar aCritical Area Master Plan shall be prepared under the direction of the Director of
Community Development. Consistent with subsection A, the Director may approve development activity within a
Rs#4ve reaCritical Area Overlay District for the purpose of allowing and encouraging a comprehensive approach
to sensitive areacritical areas protection, creation, and enhancement that results in environmental benefits that may
not be otherwise achieved through the application of the requirements of TMC Chapter 18.45.
G. The Director shall consider the following factors when determining whether a proposed Sensitive
Ar aCritical Areas Overlay and Master Plan results in an overall net benefit to the environment and is consistent
with best available science:
1. Whether the Master Plan is consistent with the goals and policies of the Natural Environment Element
and the Shorelines Element (if applicable) of the Tukwila Comprehensive Plan.
2. Whether the Master Plan is consistent with the purposes of TMC Chapter 18.45 as stated in TMC
Section 18.45.010.
3. Whether the Master Plan includes a Mitigation Plan that incorporates stream or wetland restoration,
enhancement or creation meeting or exceeding the requirements of TMC Section
18.45.090 and/or TMC Section 18.45.110 , as appropriate.
4. Whether proposed alterations or modifications to censitive arc acritical areas and their buffers and/or
alternative mitigation results in an overall net benefit to the natural environment and improves sensitise ar-acritical
area functions.
5. Whether the Mitigation Plan gives special con—sideration to conservation and protection measures
necessary to preserve or enhance anadromous fisheries.
6. Mitigation shall occur on -site unless otherwise approved by the Director. The Director may approve off -
site mitigation only upon determining that greater protection, restoration or enhancement of sensitive areacritical areas
could be achieved at an alternative location within the same watershed.
7. Where feasible, mitigation shall occur prior to grading, filling or relocation of wetlands or watercourses.
8. At the discretion of the Director, a proposed Master Plan may undergo peer review, at the expense of
the applicant. Peer review, if utilized, shall serve as one source of input to be utilized by the Director in making a
final decision on the proposed action.
83
Page 38 of 42
H. A Sensitive ArcaCritical Area Master Plan shall be subject to approval by the Director of Community
Development. Such approval shall not be granted until the Master Plan has been evaluated through preparation of an
Environmental Impact Statement (EIS) under the requirements of TMC Chapter 21.04. The EIS shall compare the
environmental impacts of development under the proposed Master Plan relative to the impacts of development under
the standard requirements of TMC Chapter 18.45. The Director shall approve the Critical Area #iv Area Master
Plan only if the evaluation clearly demonstrates overall environmental benefits, giving special consideration to
conservation or protection measures necessary to preserve or enhance anadromous fisheries.
(Ord, 2301 §1(part), 2010)
18.45.170 Critical Area
s Tracts and Easements
A. In development proposals for planned residential or mixed use developments, short subdivisions or
subdivisions, and boundary line adjustments and binding site plans, applicants shall create sensitive areacritical
areas tracts or easements, in lieu of an open space tract, per the standards of the Planned Residential Development
District chapter of this title.
B. Applicants proposing development involving uses other than those listed in TMC Section 18.45.170A, on
parcels containing sensitive areacritical areas or their buffers, may elect to establish a sensitive areacritical areas
tract or easement which shall be:
1. If under one ownership, owned and maintained by the ownership;
2. If held in common ownership by multiple owners, maintained collectively; or
3. Dedicated for public use if acceptable to the City or other appropriate public agency.
C. A notice shall be placed on the property title or plat map that sensitive areacritical area tracts or easements
shall remain undeveloped in perpetuity.
(Ord. 2301 §1(part), 2010)
18.45.180 Exceptions
A. REASONABLE USE EXCEPTIONS —
1. If application of TMC Chapter 18.45 would deny all reasonable use of the property containing wetlands,
watercourses, designated critical areas or their buffers, the property owner or the proponent of a development
proposal may apply for a reasonable use exception.
2. Applications for a reasonable use exception shall be a Type 3 decision and shall be processed
pursuant to TMC Chapter 18.104.
3. If the applicant demonstrates to the satisfaction of the Hearing Examiner that application of the
provisions of TMC Chapter 18.45 would deny all reasonable use of the property, development may be allowed
that is consistent with the general purposes of TMC Chapter 18.45 and the public interest.
4. The Hearing Examiner, in granting approval of the reasonable use exception, must determine that:
a. There is no feasible on -site alternative to the proposed activities, including reduction in size or
density, modifications of setbacks, buffers or other land use restrictions or requirements, phasing of project
implementation, change in timing of activities, revision of road and lot layout, and/or related site planning that would
allow a reasonable economic use with fewer adverse impacts to the sensitive ar acritical area.
b. As a result of the proposed development there will be no unreasonable threat to the public
health, safety or welfare on or off the development proposal site.
c. Alterations permitted shall be the minimum necessary to allow for reasonable use of the property.
d. The proposed development is compatible in design, scale and use with other development with
similar site constraints in the immediate vicinity of the subject property if such similar sites exist.
e_Disturbance of sensitive areacritical areas and their buffers has been minimized by locating
to the greatest extent possible.
e:f.All unavoidable impacts are fully mitigated.
f g_The inability to derive reasonable use of the property is not the result of:
(1) a segregation or division of a larger parcel on which a reasonable use was permittable after
the effective date of Sensitive Areas Ordinance No. 1599, June 10, 1991;
Page 39 of 42
(2) actions by the owner of the property (or the owner's agents, contractors or others under the
owner's control) that occurred after the effective date of the sen cti,r®a acritical areas ordinance provisions that
prevents or interferes with the reasonable use of the property; or
(3) a violation of the criticalsensitive areas ordinance;
g=h. The Hearing Examiner, when approving a reasonable use exception, may impose
conditions, including but not limited to a requirement for submission and implementation of an approved mitigation
plan designed to ensure that the development:
(1) complies with the standards and policies of this Chaptere sensitive arca_ ordinance to the
extent feasible; and
(2) does not create a risk of damage to other property or to the public health, safety and welfare.
la,i. Approval of a reasonable use exception shall not eliminate the need for any other permit or
approval otherwise required for a project, including but not limited to design review.
B. EMERGENCIES — Alterations in response to an emergency that poses an immediate threat to public health,
safety or welfare, or that poses an immediate risk of damage to private property may be excepted. Any alteration
undertaken as an emergency shall be reported within one business day to the Community Development Department.
The Director shall confirm that an emergency exists and determine what, if any, mitigation and conditions shall be
required to protect the health, safety, welfare and environment and to repair any damage to the sensitive areacritical
area and its required buffers. Emergency work must be approved by the City. If the Director determines that the action
taken, or any part thereof, was beyond the scope of an allowed emergency action, then the enforcement provisions
of TMC Section 18.45.195 shall apply.
(Ord. 2368 §50, 2012; Ord. 2301 §1 (part), 2010)
18.45.190 Time Limitation, Appeals and Vesting
A. Time Limitation: Type 2 Special Permission decision for interrupted buffer, buffer
averaging or other alterations shall expire in one year unless the applicant submits a
complete building permit or other construction permit within one year. Type 1 tree permit for
tree removal within sensitive areas or their buffers shall expire in one year unless an
extension is granted by the Director.
The Director may grant an extension if:
1. Unforeseen circumstances or conditions necessitate the extension of the permit; and
2. Termination of the permit would result in unreasonable hardship to the applicant; and the applicant is
not responsible for the delay; and
3. The extension of the permit will not cause substantial detriment to existing uses, critical areas, or
critical area buffers in the immediate vicinity of the subject property.
B. Appeals: Any appeal of a final decision made by the Community Development
Department, pursuant to TMC Chapter 18.45, shall be an appeal of the underlying permit or approval.
Any such appeal shall be processed pursuant to TMC Section 18.108.020 and TMC Chapter 18.116.
In considering appeals of decisions or conditions, the following shall be considered:
1. The intent and purposes of this Chapterc sensitive areo_c ordinance;
2. Technical information and reports considered by the Community Development Department; and
3. Findings of the Director, which shall be given substantial weight.
C. Vesting: Projects are vested to critical area ordinance in effect at the time a complete building permit
is submitted except for short plats, subdivisions and shoreline permits. Short plats or subdivisions are vested
at the time complete application is submitted for preliminary plats. For short plats and subdivisions which
received preliminary plat approval prior to the adoption of this ordinance, building permits on the lots shall be
considered under the critical areas ordinance in effect on the date of the preliminary plat approval provided
complete building or construction permits are submitted within one year of the final plat approval. Vesting
provisions for shoreline permits are provided in TMC 18.44
(Ord. 2301 §1 (part), 2010)
85
Page 40 of 42
18.45.195 Violations: = -
A. VIOLATIONS. The following actions shall be considered a violation of this chapter:
1. To use, construct or demolish a structure or to conduct clearing, earth -moving, construction or other
de- velopment not authorized under a Special Permission, Rea- sonable Use or other permit where such permit is
required by this chapter.
2. Any work that is not conducted in accordance with the plans, conditions, or other requirements in a
permit approved pursuant to this chapter, provided the terms or conditions are stated in the permit or the
approved plans.
3. To remove or deface any sign, notice, complaint or order required by or posted in accordance with
this chapter.
4. To misrepresent any material fact in any application, plans or other information submitted to obtain any
sensitive areacritical area use, buffer reduction or development authorization.
5. To fail to comply with the requirements of this chapter.
B. ENFORCEMENT. It shall be the duty of the Community Development Director to enforce Violations
o f this chapter shall be enforced pursuant to the terms and conditions of TMC Chapter 8.45.
C. INSPECTION ACCESS.
Any permit issued pursuant to this chapter shall include a right of entry to allow for inspection by the
city.
1.
2. Upon completion of all requirements of a permit, the applicant shall request a final inspection by
contacting the planner of record. The permit process is complete upon final approval by an authorized
representative of the Community Development Director.
D. PENALTIES.
1. Except as provided otherwise in this sectionA any violation of any provision of this chapter, or
failure to comply with any of the requirements of this chapter, shall be subject to the penalties prescribed in TMC
Chapter 8.45, "Enforcement,"
chapter.
Page 41 of 42
2]tshall not be edefense to the prosecution for failure to obtain 8 permit required by this chapter that
8 contractor, subcontractor, person with responsibility On the site, or person authorizing [vdirecting the
work erroneously believed apermit had been issued Vuthe property owner orany other person.
3. Penalties for Tree Removal
a. Each unlawfully removed or damaged tree shall constitute a anpenyto violation.
U.The amount Ofthe penalty shall b8$1.00Oper tree 0rupt0the marketable value Ofeach tree removed
or damaged as determined by an |GAnmrtifind arbnrisL The Director may elect not to seek penalties ormay
reduce the p8n8|1i8S if he/she determines the CirCUmSt8nC8S do not warrant imposition of any or all of the
civil penalties.
c Any illegal removal of required trees shall be subject to obtaining o tree permit and replacement with
trees that meet or exceed the functional value of the removed trees. In addition, any shrubs and qroundcover
removed without City approval shall b8replaced.
d.Toreplace the tree canopy lost due to the tree removal, additional trees must be planted on -site, Payment
may be made into the Qiy'S Tree Fund if the number of replacement trees cannot be 8CC0mmndG03d On'
Site. The number of replacement trees required will be based On the size of the 1r9S(S) removed as stated
inTMC 1845.15813�
E. REMEDIAL MEASURES REQUIRED. In addition 0upenalties provided inTMCChapter 8.45.the Director
may require any person conducting work in violation of this chapter to mitigate the impacts of unauthorized work by
carrying out nBmSdiG| measures.
1. Remedial mS8SurS8 must conform to the policies and guidelines 0fthis chapter.
2. The nn8t of any remedial measures necessary to onnoctvio|ad0n/G\ of this chapter Dh8U be bn08
bythe property owner and/or applicant.
F. INJUNCTIVE RELIEF.
1. Whenever the City has reasonable cause tObelieve that any person iSviolating 0rthreatening 0Jviolate
the sensitive oroonhUca| areas nagu|odnn3 nrany rule Orother provisions adopted or issued pursuant to these
regulations, it may either before or after the institution of any other action or proceeding authorized by this ordinance,
institute 3civil action iOthe name Ofthe City for injunctive relief tOrestrain the violation O[threatened violation. Such
action shall bebrought inKing County Superior Court.
2. The institution of an 8CUOO for injunctive relief under this section Sh8U not n3|i8v8 any p8dv 03 such
proceedings from any civil or criminal penalty prescribed for viO|8UOnS Of these regulations.
G. ABATEMENT. ' Any use, structure, development O[work that occurs iOviolation 0fthese regulations, O[iO
viO|8U0O of any lawful order O[requirement Ofthe Director pursuant 03this section, shall b8deemed 03b88public
nuisance and may b8abated inthe manner provided by the T M C C h a pterTukwila Municipal Codo, Section
8451O5�
18.45.200 Recording Required
The property owner receiving approval Of3use Ordevelopment permit pursuant h]TMCChapter 18.45shall
v8COu1 the City -approved Site plan, clearly delineating the wetland, watercourse, areas Ofpotential g8V|OgiC
instability O[abandoned mine and their buffers designated byTMC G8CU0OS 18.45.000' 18.45.090' 10.45.100,
18.45.120' 10.45.140 and 18.45.150 with
the King County Division of Records and Elections. The face of the site plan must include a statement that the
provisions OfTMC Chapter 18.45.8SOfthe effective date Ofthe ordinance from which TK4CChapter 18.45derives
OriSthereafter amended, control use and development Ofthe subject property, and provide for any responsibility
of the property 0wO8[ for the nl8iOV8O8OC8 Or QOrreCUOO of any latent defects or deficiencies. AdditiOnoUy, the
applicant shall provide data (GPSorsurvey data) for updaUnq the Qty'5critical area maps.
18.45.210 Assurance Device
87
Page 42 of 42
A. In appropriate circumstances, such as when mitigation is not completed in advance of the project, the
Director may require a letter of credit or other security device acceptable to the City to guarantee performance and
maintenance requirements of TMC Chapter 18.45. All assurances shall be on a form approved by the City Attorney
and be equal to 150% of the cost of the labor and materials for implementation of the approved mitigation plan.
B. When alteration of a sensitive arcacritical area is approved, the Director may require an assurance device,
on a form approved by the City Attorney, to cover the cost of monitoring and maintenance costs and correction of
possible deficiencies for five years.
If at the end of five years
performance standards are not being achieved, an increase in the security device may be required by the Director.
When another agency requires monitoring beyond the City's time period, copies of those monitoring reports shall be
provided to the City.
C. The assurance device shall be released by the Director upon receipt of written confirmation submitted and
confirmed by the City to the Department from the applicant's qualified professional that the mitigation or
restoration has met its performance standards and is successfully established. Should the mitigation or restoration
meet performance standards and be successfully established in the third or fourth year of monitoring, the City may
release the assurance device early. The assurance device may be held for a longer period, if at the end of the
monitoring period, the performance standards have not been met or the mitigation has not been successfully
established. In such cases, the monitoring period will be extended and the bond held until the standards have been
met.
D. Release of the security does not absolve the property ownerofresponsibilityformaintenanceorcorrecting
latent defects or deficiencies or other duties under law.
(Ord. 2301 §1 (part), 2010)
18.45.220 Assessment Relief
A. FAIR MARKET VALUE — The King County Assessor considers ccncitive arcacritical area regulations in
determining the fair market value of land under RCW 84.34.
B. CURRENT USE ASSESSMENT— Established se^ tive arcacritical area tracts or easements, as defined in
the Definitions chapter of this title and provided for in TMC Section 18.45.170, may be classified as open space and
owners thereof may qualify for current use taxation under RCW 18.34; provided, such landowners have not received
density credits, or setback or lot size adjustments as provided in the Planned Residential Development District chapter
of this title.
C. SPECIAL ASSESSMENTS — Landowners who qualify under TMC Section 18.45.220 B shall also be
exempted from special assessments on the sensitive or acritical area tract or easement to defray the cost of municipal
improvements such as sanitary sewers, storm sewers and water mains.
(Ord. 2301 §1 (part), 2010)
T C 18.70.050 onconfor
n
uctures
Where a lawful structure exists at the effective date of adoption of this title that could not be built under the terms of
this title by reason of restrictions on area, development area, height, yards or other characteristics of the structure, it
may be continued so long as the structure remains otherwise lawful subject to the following provisions:
1. No such structure may be enlarged or altered in such a way that increases its degree of nonconformity. Ordinary
maintenance of a nonconforming structure is permitted, pursuant to TMC Section 18.70.060, including but not limited
to painting, roof repair and replacement, plumbing, wiring, mechanical equipment repair/replacement and
weatherization. These and other alterations, additions or enlargements may be allowed as long as the work done
does not extend further into any required yard or violate any other portion of this title. Complete plans shall be
required of all work contemplated under this section.
2. Should such structure be destroyed by any means to an extent of more than 50% of its replacement cost at time
of destruction, in the judgment of the City's Building Official, it shall not be reconstructed except in conformity with
provisions of this title, except that in the LDR zone, structures that are nonconforming in regard to yard setbacks or
sensitive area buffers, but were in conformance at the time of construction may be reconstructed to their original
dimensions and location on the lot.
3. Should such structure be moved for any reason or any distance whatsoever, it shall thereafter conform to the
regulations for the zone in which it is located after it is moved.
4. When a nonconforming structure, or structure and premises in combination, is vacated or abandoned for 24
consecutive months, the structure, or structure and premises in combination, shall thereafter be required to be in
conformance with the regulations of the zone in which it is located. Upon request of the owner, the City Council may
grant an extension of time beyond the 24 consecutive months.
5. Residential structures and uses located in any single-family or multiple -family residential zoning district and in
existence at the time of adoption of this title shall not be deemed nonconforming in terms of bulk, use, or density
provisions of this title. Such buildings may be rebuilt after a fire or other natural disaster to their original dimensions
and bulk, but may not be changed except as provided in the non -conforming uses section of this chapter.
6. Single-family structures in single- or multiple -family residential zone districts that have legally nonconforming
building setbacks, shall be allowed to expand the ground floor only along the existing building line(s), so long as the
existing distance from the nearest point of the structure to the property line is not reduced, and the square footage of
new intrusion into the setback does not exceed 50% of the square footage of the current intrusion.
7. In wetlands, watercourses and their buffers, existing structures that do not meet the requirements of the
Critical Areas Overlay District chapter of this title may be remodeled, reconstructed or replaced, provided
that:
a. The new construction does not further intrude into or adversely impact an undeveloped criticalsensitivo area or the
required buffer except where an interrupted buffer waiver has been granted by the Director. However, legally
constructed buildings, other than accessory structures may:
i) Expand vertically to add upper stories in exchange for buffer enhancement; provided no significant tree
is removed.
ii) Expand laterally along the building side that is opposite of critical area up to a maximum of 1000 sq. ft;
provided that expansion is outside 75 percent of the required buffer; buffer enhancement is proposed;
and no significant tree is removed.
89
iii) Expand laterally along the existing building lines in exchange for buffer enhancement; provided the
expansion into the buffer is less than 50 percent of the current encroachment or 500 sq. ft, whichever is
less, expansion is outside 75 percent of the required buffer, and no significant tree is removed.
iv) Enclose within existing footprint in exchange for buffer enhancement; provided no significant tree is
removed.
b. The new construction does not threaten the public health, safety or welfare; and
c. The structure otherwise meets the requirements of this chapter.
8. In areas of potential geologic instability, coal mine hazard areas, and buffers, as defined in the Critical Sensitive
Areas Overlay District chapter of this title, existing structures may be remodeled, reconstructed or replaced, provided
that:
a. The new construction is subject to the geotechnical report requirements and standards of TMC Sections
18.45.120B and 18.45.120C;
b. The new construction does not threaten the public health, safety or welfare;
c. The new construction does not increase the potential for soil erosion or result in unacceptable risk or damage to
existing or potential development or to neighboring properties; and
d. The structure otherwise meets the requirements of this chapter.
the nonconforming structure
90