HomeMy WebLinkAboutOrd 1599 - Sensitive Areas and BuffersWashington
Cover page to Ordinance 1599
The full text of the ordinance follows this cover page.
AN ORDINANCE OF THE CITY OF T KK VICLA, WASHIN TON,
REGULATING DEVELOPMENT .ENT ;N SENSITIVE AREAS AND BUFFERS;
'AMENDING OR) INANOE NOS 12,47 AND 128 AND TUK' ILA
MUNICIPAL CO4 E (TM) TITLE 18; AMENDING IRDI IAN E NOS.
1331 AND 1334 AND 'TMC TITLE 2'L04,; AMENDING ORDINANCE NO
1014 AND TMC TITLE 17; AND .PROVIDING FOR AN ,EFFECT1VE DATE.
Ordinance 1599 was amended or repealed by the following
ordinances.
Se
ion(s)
A
AMENDED
nded
A
vended by Ord #
1607
1711
7(5)
2502
7(1), 7(3), 7(6)
2711
Se
ion(s)
R
REPEALED
peal+
Repealed by Ord #
2-5
1758
6
1833
1W(ie
ilk
1908
CITY OF TUKVVILA
MUNICIPAL CODE (TMC) TITLE 18; AMENDING ORDINANCE NOS.
1331 AND 1334 AND TMC TITLE 21.04; AMENDING ORDINANCE NO
1014 AND TMC TITLE 17; AND PROVIDING FOR AN EFFECTIVE DATE.
WHEREAS, the City Council considered regulation of development on sensitive areas within the City
of Tukwila and referred the issue to the Planning Commission; and
WHEREAS, the State of Washington has subsequently through RCW 36.70A mandated that local
jurisdictions pass legislation protecting sensitive areas; and
WHEREAS, the SEPA Responsible Official made a determination of non- significance on October 25,
1989; and
WHEREAS, the City Council upheld the determination of non significance at an appeal heard on
December 18, 1989; and
WHEREAS, the Planning Commission held public hearings on November 9, 1989, November 16,
1989, August 30, 1990, and September 6, 1990; and
WHEREAS, the City Council President and the Mayor appointed a citizens' committee on November
27, 1989 to study the issue; and
WHEREAS, the City Council authorized certain consultants' reports as follows:
1. Wetlands Inventory by Jones Stokes Associates, Inc., dated September 1989; superseded by
Water Resource Rating and Buffer Recommendations dated May 1990.
2. Abandoned Underground Coal Mine Hazard Assessment by Hart Crowser, Inc., dated May 3,
1990.
3. Geologic Hazards Evaluation, by GeoEngineers dated May 9, 1990.
4. Tukwila. Hillsides Design and Development Standards by Johnson Architecture /Planning dated
March 6, 1990
5. Watercourse Rating Data Sheets by Jones Stokes, Inc., dated October 1990;
and
WHEREAS, After considering the testimony at public hearings, the recommendations of the citizens'
committee and the consultants' reports, the Planning Commission made Findings and recommended a draft
Sensitive Areas Ordinance to the City Council on October 25, 1990; and
WHEREAS, public hearings were held before the City Council on April 22, 1991 and April 24, 1991;
and
WHEREAS, after considering the recommendations of the Planning Commission and the citizens'
committee, the consultants' reports and the testimony at the public hearings and after numerous public
meetings of the City Council, the City Council has determined that it is necessary and desireable and in the
interest of the public health, safety and welfare to regulate development on sensitive areas and their buffers;
NOW, THEREFORE, THE CITY COUNCIL OF THE CITY OF TUKWILA, WASHINGTON, DO
ORDAIN AS FOLLOWS:
SECTION 1. FINDINGS_ The City Council finds as follows:
1. The environmental features identified as sensitive areas which require regulation by Tukwila are: coal
mine hazard areas, areas of potential geologic instability, watercourses, wetlands and important geologic
and archaeologic resources.
2. The Sensitive Areas Ordinance will implement goals and policies of the 1978 Tukwila Comprehensive
Land Use Policy Plan and the Puget Sound Water Quality Management Plan.
3. The 1990 Washington State Legislature approved ESHB 2929 (1990 Wash. Laws 17) (RCW 36.70A)
which mandates that certain counties, and cities within those counties, address the protection of critical
Sensitive Areas Ordinance Page 2
areas. Critical areas as defined in ESHB 2929 correlate generally with the Tukwila definitions and
categories of sensitive areas. This Sensitive Areas Ordinance is designed to meet the challenges and
satisfy the requirements of this act with regard to all critical areas except aquifer recharge areas and flood
plains which will require a different regulatory approach or are regulated in an existing title of the
Tukwila Municipal Code.
4. Regulation of the use of sensitive areas benefits property owners by preventing and avoiding activities
which would have adverse impacts on property.
5. Development in wetlands, watercourses and erosion hazard areas results in: 1) increased soil erosion
and sedimentation of downstream water bodies, including navigable channels; 2) increased shoreline
erosion; 3) degraded water quality due to increased turbidity and loss of pollutant removal processes;
4) elimination or degradation of wildlife and fisheries habitat; 5) loss of fishery resources from water
quality degradation, increased peak flow rates, decreased summer low flows, and changes in the
stream flow regimen; 6) loss of stormwater retention capacity and slow release detention resulting in
flooding, degraded water quality, and changes in the stream flow regimen of watersheds.
6. Development in areas of geologic instability present a danger to the development on the site as well as
neighboring sites and natural resources, and require special design, construction and site development
measures to minimize risks from these hazards.
7. Tukwila is in an earthquake prone region subject to ground shaking, subsidence, landslide and
liquefaction. Special building design and construction measures are necessary to minimize risk from
this hazard.
8. In their natural state, wetlands and watercourses provide many valuable social and ecological services,
which are critical and cannot adequately be replicated or replaced, including:
a. controlling flooding and stormwater runoff by storing or regulating natural flows;
b. protecting water resources by filtering out water pollutants, processing biological and chemical
oxygen demand, recycling and storing nutrients, and serving as settling basins for naturally
occurring sedimentation;
c. providing areas for groundwater recharge;
d. providing habitat areas for many species of fish, wildlife, and vegetation, many of which are
dependent on these water resources for their survival;
e. providing open space and visual relief from intense development in urbanized area;
f. providing recreation opportunities; and
g. serving as areas for scientific study and natural resource education.
9. Tukwila in enacting this ordinance has relied on extensive scientific documentation and testimony
concerning these sensitive areas and the appropriate methods and mechanisms for their protection.
This documentation is available in the Department of Community Development in file 89 -2 -CA:
Sensitive Areas Ordinance.
SECTION 2. ORDINANCE NO. 1247 AND TMC 18.06 AMENDED. TMC 18.06 is hereby
amended to add the following sections:
18.06.045 Applicant
"Applicant" means any person or business entity which applies for a development proposal,
permit or approval subject to review under the Sensitive Areas Chapter.
18.06.049 Areas of Potential Geologic Instability.
"Area of Potential Geologic Instability" means those areas subject to potential landslides and /or
potential seismic instabilities.
18.06.175 Compensatory Mitigation
"Compensatory mitigation" means replacing project induced wetland and buffer losses or impacts,
and includes, but is not limited to, the following:
1. Restoration Actions performed to reestablish wetland and its buffer functional char-
acteristics and processes which have been lost by alterations, activities, or catastrophic
events within an area which no longer meets the definition of a wetland.
2. Creation Actions performed to intentionally establish a wetland 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 or its buffer so that the functions they provide are of a higher quality.
Sensitive Areas Ordinance Page 3
18.06.176 Constructed Wetlands or Watercourses.
"Constructed wetland" or "constructed watercourses" means those wetlands or watercourses
which an applicant can demonstrate were intentionally created from non wetland or non
watercourse sites, including, but not limited to, irrigation and drainage ditches, grass -lined swales,
canals, detention facilities, wastewater treatment facilities, farm ponds, and landscape amenities;
and does not mean those wetlands and watercourses created through compensatory mitigation.
18.06.203 Density Transfer.
"Density transfer" is a percentage number which represents a credit for housing units which are
not allowed to be built in wetlands, watercourses or their buffers. The density transfer is used in
a formula for determining the number of residential units allowed on the buildable portion of a lot
containing wetlands, watercourses and their buffers.
18.06.255 Emergent Wetland.
"Emergent wetland" means a regulated wetland with at least 30 percent of the surface area
covered by erect, rooted, herbaceous vegetation as the uppermost vegetative strata.
18.06.262 Essential street, road, right -of -way or utility.
"Essential street, road, right -of -way or utility" means a utility facility,utility system, street, road or
right-of -way where no feasible alternative location exists based on an analysis of technology and
system efficiency.
18.06.295 Forested wetland.
"Forested wetland" means a regulated wetland with at least 20 percent of the surface area covered
by trees greater than 20 feet in height.
18.06.322 Geologist.
"Geologist" means a person who has earned a degree in geology from an accredited college or
university, or a person who has equivalent educational training and has experience as a practicing
geologist.
18.06.323 Geotechnical Engineer.
"Geotechnical engineer" means a practicing, geotechnical /civil engineer licensed as a professional
Civil Engineer with the State of Washington who has at least four years of professional
employment as a geotechnical engineer with experience in landslide evaluation.
18.06.385 Impervious Surface.
"Impervious Surface" means those hard surfaces which prevent or retard the entry of water into
the soil in the manner that such water entered the soil under natural conditions pre- existent to
development, grading or alteration of the land. Such surfaces include, but are not limited to,
rooftops, asphalt or concrete paving, driveways, parking lots, walkways, patio areas, storage areas,
compacted surfaces, or other surfaces which similarly affect the natural infiltration or runoff
patterns existing prior to development.
18.06.388 Isolated Wetlands.
"Isolated wetlands" means those wetlands which:
1. are outside of and not contiguous to any 100 -year floodplain of a lake, river, or stream that is
designated as a shoreline according to the City's Shoreline Master plan; and
2. have no contiguous hydric soil and hydrophytic vegetation between the wetland and any
surface water.
18.06.455 Lot Coverage.
"Lot Coverage" means the surface of the subject property covered with impervious surface, other
than outdoor pools.
18.06.585 Ordinary High Water Mark
"Ordinary high water mark" (OHWM) means the mark that will be found by examining the bed
and banks of a stream and ascertaining where the presence and action of waters are so common
and usual as to distinctly mark the soil from that of the abutting upland, in respect to vegetation.
*In any area where the OHWM cannot be determined, the channel bank shall be substituted. In
braided channels, the OHWM or substitute shall be measured so as to include the entire stream.
18.06.605 Performance Standards.
Specific criteria for fulfilling environmental goals, and for beginning remedial action, mitigation, or
contingency measures, which may include water quality standards, or other hydrological,
geological, or ecological criteria.
18.06.625 Reach.
"Reach" is a segment of a watercourse with uniform characteristics.
Sensitive Areas Ordinance Page 4
18.06.655 Regulated Activities
"Regulated Activities" means any of the following activities which are directly undertaken or
originate in a regulated wetland or watercourse or their buffers:
1. The removal, excavation, grading, or dredging of soil, sand, gravel, minerals, organic matter,
or material of any kind;
2. The dumping, discharging, or filling with any material;
3. The draining, flooding, or disturbing of the water level or water table;
4. The driving of pilings;
5. The placing of obstructions;
6. The construction, reconstruction, demolition, or expansion of any structure;
7. The 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 Chapter 76.09 RCW 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 pollutants.
18.06.656 Regulated Wetlands.
"Regulated wetlands" means ponds or lakes thirty acres or less and those lands subject to the
"wetland" definition contained in this chapter. Isolated wetlands that are 400 square feet or
smaller in area may not require compensatory mitigation.
18.06.692 "Scrub -Shrub Wetland.
"Scrub -shrub wetland" means a regulated wetland with at least 30 percent of its surface area
covered by woody vegetation less than 20 feet in height as the uppermost strata.
18.06.695 Sensitive Areas.
"Sensitive Areas" means wetlands; watercourses; areas of potential geologic instability other than
Class 1 areas; abandoned coal mine areas; and important geological or archaeological sites.
18.06.697 Sensitive Area Buffer.
"Sensitive Area Buffer" means the area contiguous to a sensitive area that is required for the
continued maintenance, function and structural stability of the sensitive area.
18.06.698 Sensitive Area Tract.
"Sensitive Area Tract" means a tract which is created to protect the sensitive area and its buffer,
whose maintenance is assured, and which is recorded on all documents of title of record for all
affected lots and subsequent owners.
18.06.762 Significant Tree.
"Significant tree" is any woody vegetation, in any sensitive area or buffer, that is essential to or
contributes to the function of a sensitive area and its buffers.
18.06.915 Utilities.
"Utilities" are all lines and facilities related to the provision, distribution, collection, transmission or
disposal of water, storm and sanitary sewage, oil, gas, power, information, telecommunication
and telephone cable, or refuse, and includes facilities for the generation of electricity.
18.06.935 Watercourse.
"Watercourse" means a course or route formed by nature or modified by man, generally
consisting of a channel with a bed and banks or sides substantially throughout its length along
which surface water flows naturally other than the Green /Duwamish River. The channel or
bed need not contain water year round. Watercourses do not include irrigation ditches, storm
water runoff channels or devices, or other entirely artificial watercourses unless they are used by
salmonids or to convey or pass through stream flows naturally occurring prior to construction of
such devices.
18.06.938 Wetlands.
"Wetlands" means those areas that are inundated or saturated by ground 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. Constructed wetlands are not
considered wetlands for the purpose of this Chapter. However, those artificial wetlands
intentionally created from non wetland areas to mitigate conversion of wetlands as permitted by
the City shall be considered wetlands.
Sensitive Areas Ordinance Page 5
18.06.939 Wetland Edge.
"Wetland edge" means the boundary of a wetland as delineated based on the methodology used
in the "Federal Manual for Identifying and Delineating Jurisdictional Wetlands" (1989), as revised
or updated.
SECTION 3. ORDINANCE NO. 1247 AND TMC 18 AMENDED. A new chapter 18.45 entitled
"Sensitive Areas Overlay Zone" is hereby added to the Tukwila Municipal Code (TMC) to read as follows:
18.45.010 Purpose
A. The purpose of the Sensitive Areas Overlay Zone is to establish special standards for the use and
development of lands based on the existence of natural conditions thereon in order to protect
environmentally sensitive areas, including the natural character of Tukwila's wooded hillsides.
B. Standards are hereby established to meet the following goals of protecting environmentally
sensitive areas:
1. Minimize developmental impacts on the natural functions and values 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 distinctive features of natural lands and
wooded hillsides.
7. Prevent unlawful disturbance of archaeologic or geologic sites with historic or prehistoric
artifacts.
8. Balance the private rights of individual property owners with the preservation of envi-
ronmentally sensitive areas.
9. Prevent the loss of wetland and watercourse function and acreage, and strive for a gain over
present conditions.
18.45.020 Sensitive Area Designation, Rating methodologies, Classifications and Applicability.
A. This chapter applies to any use or development proposed on any legal lot of record, any portion of
which is a sensitive area or a sensitive area buffer as defined in TMC Sections 18.06.695 and
18.06.697, and specifically including one or more of the following and their buffers:
1. Abandoned coal mines
2. Areas of Potential Geologic Instability Class 2,3,4 and seismic instability areas (TMC
18.06.049 and 18.45.020(E))
3. Wetlands (TMC 18.06.938)
4. Watercourses (TMC 18.06.935)
5. Areas that contain archaeological remnants of value to the archaeological research
community, which includes but is not limited to colleges, universities or societies of
professional archaeologists, or which is designated as important to save as a record of
the area's past by the State Office of Archaeology and Historic Preservation.
B. Sensitive Areas Maps and Inventories.
1. The distribution of many sensitive areas in Tukwila is displayed on the Sensitive Areas
Maps, dated 1990, and on file with the DCD.
2. Studies, preliminary inventories and ratings of potential sensitive areas are on file with the
DCD in the Sensitive Areas Notebook dated May 1990.
3. The maps and preliminary inventories and ratings are hereby adopted by reference. The
actual presence or absence of sensitive areas as defined by or otherwise referred to in this
chapter and as determined by the City of Tukwila will govern. The actual ratings and
buffers for any sensitive area will be determined by the City of Tukwila using the
methodologies and procedures provided in this chapter for each type of sensitive area.
4. All revisions, updates and reprintings of sensitive areas maps, inventories, ratings and
buffers shall conform to this ordinance.
Sensitive Areas Ordinance Page 6
C. Wetlands:
For the purposes of this Chapter, wetlands are defined in TMC 18.06.938. A wetland boundary is
the line delineating the outer edge of a wetland established by using the Federal Manual for
Identifying and Delineating Jurisdictional Wetlands dated January 10, 1989, as revised or updated,
and jointly published by the U.S. Environmental Protection Agency, the U.S. Fish and Wildlife
Service, the U.S. Army Corps of Engineers, and the U.S. Soil Conservation Service.
Wetland types and rating criteria are listed below.
1. Type 1 Wetlands. Those wetlands which meet any of the following criteria:
a. The presence of species listed by the federal government or state as endangered, or
threatened or the presence of critical or outstanding actual habitat for those species;
b. Wetlands having 40% to 60% permanent open water in dispersed patches with two or
more classes of vegetation;
c. Wetlands equal to or greater than five acres in size and having three or more wetland
classes, one of which may be substituted by permanent or open water; or
2. Type 2 Wetlands. Those wetlands which meet any of the following criteria:
a. Wetlands greater than one acre in size;
b. Wetlands equal to or less than one acre in size and having three or more wetland
classes;
c. Wetlands equal to or less than one acre that have a forested wetland class comprised of
at least 20 percent coverage of total surface area; or
d. The presence of heron rookeries or raptor nesting trees.
e. The presence of native plant associations of infrequent occurrence.
3. Type 3 Wetlands. Those wetlands which are equal to or less than one acre in size and that
have two or fewer wetland classes.
For the purposes of this section, the U.S. Fish and Wildlife Service's Classification of Wetlands and
Deepwater Habitats of the United States FWS /OBS -79/31 (Cowardin et al, 1979) contains the
descriptions of wetland classes and subclasses.
D. Watercourses:
For the purposes of this Chapter, watercourses are defined in TMC 18.06.935. The City of
Tukwila's Watercourse Study (1990) includes the methodology and criteria that will be used for
determining watercourse ratings.
Watercourse ratings are based on the existing habitat functions. Each segment or reach of a
watercourse is rated individually. The rating system will score a reach point total for each side of
the watercourse. Watercourse types, rating scores, and rating criteria are described below.
1. Watercourse Types and Rating Scores:
a. Type 1 Watercourse 21 to 33 Points
b. Type 2 Watercourse 11 to 20 Points
c. Type 3 Watercourse -3 to 10 Points
2. Watercourse Rating Criteria
a. Instream Features
(1) Width of Watercourse A measure of the average width of the channel at the
ordinary high water mark.
(2) Channel Capacity Quantifies the ability of the channel to convey high flows
without flooding.
(3) Channel Stability Measures the stability of the channel by evaluating evidence
of bank failure, scour, and downcutting.
(4) Fish Use and Fish Habitat Anadromous and resident salmonid need protection
measures if present. Rating depends on the number of different types of habitat
present.
b. Corridor Quality
(1) Width of Unmaintained Vegetation A measure of the width of unmaintained
vegetation from the Ordinary High Water Mark.
(2) Vegetation Diversity Quantifies the elements of terrestrial habitat associated with
the watercourse corridor.
Sensitive Areas Ordinance Page 7
(3) Corridor Barrier Function Provides some measure of effectiveness of the buffer
to limit intrusion and disturbance.
(4) Surrounding Land Use Evaluation of the land use immediately outside the of the
vegetated corridor.
E. Areas of Potential Geologic Instability.
Areas of potential geologic instability are defined in TMC 18.06.049, and are classified as follows:
1. Class 1 areas, where landslide potential is low, which slope less than 15 percent.
2. Class 2 areas, where landslide potential is moderate, which slope between 15 and 40 per-
cent and which are underlain by relatively permeable soils.
3. Class 3 areas, where landslide potential is high, which include areas sloping between 15
and 40 percent and which are underlain by relatively impermeable soils or by bedrock, and
which also include all areas sloping more steeply than 40 percent.
4. Class 4 areas, where landslide potential is very high, which include sloping areas with
mappable zones of ground water seepage, and which also include existing mappable
landslide deposits regardless of slope.
5. Areas of potential seismic instability, with soft soils, loose sand and a shallow ground water
table.
F. Sensitive Areas Special Studies
1. Required. An applicant for a development proposal that includes sensitive areas, shall
submit those studies as required by the City to adequately identify and evaluate the
sensitive area and its buffers.
2. Waiver. If there is agreement between the Director of DCD and the applicant concerning the
sensitive area classification and type, the Director of DCD may waive the requirement for
sensitive area studies. There must be substantial evidence that the sensitive area
classification is correct, that there will be no alteration of the sensitive areas or buffers, and
that the goals, purposes, objectives and requirements of this ordinance will be followed.
3. Review of studies. The Department of Community Development will review the
information submitted in the sensitive area studies to verify the information, confirm the
nature and type of the sensitive area, and ensure the study is consistent with this Chapter.
G. When this chapter imposes greater restrictions or higher standards upon the development or use
of land than other laws, ordinances or restrictive covenants, the provisions of this chapter shall
prevail.
H. All other relevant standards of the TMC must also be met.
18.45.030 Interpretation
The provisions of this chapter shall be held to be minimum requirements in their interpretation
and application and shall be liberally construed to serve the purposes of this chapter.
18.45.040 Sensitive Area Buffers
A. General.
1. Any land alteration must be located out of the buffer areas as required by this section.
Buffers in general are intended to:
a. Minimize long -term impacts of development on properties containing Sensitive Areas;
b. Protect Sensitive Areas from adverse impacts during development;
c. Preserve the edge of the Sensitive Area for its critical habitat value; and
d. Prevent loading of potentially unstable slope formations.
Land alteration is permitted for public access, supplemental planting and approved land uses
of 18.45.080.
An undisturbed sensitive area or buffer may substitute for the yard setback and landscape
requirements of TMC 18.50 and 18.52.
2. Wetland and Watercourse Buffers are intended to:
a. Provide shading to maintain stable water temperatures and vegetative cover for
additional wildlife habitat;
b. Provide input of organic debris, and uptake of nutrients;
c. Provide an area to stabilize banks, to absorb overflow during high water events, and to
allow for slight variation of aquatic system boundaries over time due to hydrologic or
climatic effects;
d. Reduce erosion and increased surface water runoff;
Sensitive Areas Ordinance Page 8
e. Reduce loss of or damage to property;
f. Intercept fine sediments from surface water runoff and serve to minimize water
quality impacts;
g. Preserve the edge for its habitat value; and
h. Protect the sensitive area from human and domestic animal disturbance.
3. Buffers for Areas of Potential Geologic Instability are intended to:
a. Protect slope stability;
b. Provide erosion control and attenuation of precipitation surface and storm water runoff;
c. Reduce loss of or damage to property; and
d. Preserve the natural character of wooded hillsides where they exist.
B. Special Buffer Studies.
Applicants for a use or development on a legal lot of record within one hundred feet of a sensitive
area shall be required to conduct a sensitive area study to provide a buffer analysis for the
sensitive area. This study may be waived by the DCD Director following 18.45.020 F.2.
C. Ratings and Buffer Width.
Ratings and appropriate buffers for wetlands and watercourses are listed below.
1. For wetlands:
a. Type 1 100 -foot wide buffer
b. Type 2 50 -foot wide buffer
c. Type 3 25 -foot wide buffer
2. For watercourses, the buffer shall be as follows:
a. Type 1 70 -foot wide buffer
b. Type 2 35 -foot wide buffer
c. Type 3 15 -foot wide buffer
3. Setbacks:
a. All commercial and industrial developments shall be set back 15 feet and all residential
development shall be set back 10 feet. This setback shall be measured from the
foundation to the buffer's edge.
b. The Director of DCD may waive setback requirements when a site plan demonstrates
there will be no impacts to the buffer zone.
4. Variation of Standard or Creation of Variable Width Wetland/Watercourse Buffers:
a. The DCD Director may reduce the standard wetland /watercourse buffers on a case -by-
case basis, provided the buffer does not contain slopes 15% or greater. The approved
buffer width shall not result in greater than a 50 percent reduction in width, and the
reduced buffer shall not be less than 15 feet for wetlands and 10 feet for watercourses.
Any buffer reduction proposal must demonstrate to the satisfaction of the DCD Director
that it will not result in direct or indirect, short -term or long -term adverse impacts to
wetlands or watercourses, and that:
(1) The buffer is vegetated and includes an enhancement plan as may be required to
improve the buffer function and value; or
(2) If there is no significant vegetation in the buffer, a buffer may be reduced only if
an enhancement plan is provided. The plan must include using a variety of
native vegetation that improves the functional attributes of the buffer and
provides additional protection for the wetland or watercourse functions and
values.
b. Buffers for all types of wetlands and 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 wetland or watercourse study by a qualified
wetlands specialist or expert which documents the basis for such increased width. An
increase in buffer width may be appropriate when:
(1) The development proposal has the demonstrated potential for significant adverse
impacts upon the wetland or watercourse which can be mitigated by an
increased buffer width; or
(2) The area serves as habitat for endangered, threatened, sensitive or monitor
species listed by the federal government or the State of Washington.
Sensitive Areas Ordinance Page 9
c. Every reasonable effort shall be made to maintain the existing viable plant life in the
buffers. Vegetation may be removed from the buffer as part of an enhancement plan
approved by the Director of DCD. Enhancements will ensure that slope stability and
wetland and watercourse quality will be maintained or improved. Any disturbance of
the buffers for wetlands or watercourses shall be replanted with a diverse plant
community of native northwest species that are appropriate for the specific site as
determined by the DCD Director.
If the vegetation must be removed, or because of the alterations of the landscape the
vegetation becomes damaged or dies, then the applicant for permit must replace
existing vegetation along wetlands and watercourses with comparable specimens,
approved by the DCD Director, which will reproduce the existing buffer value within
5 years.
d. The DCD Director shall require subsequent corrective actions and long -term
monitoring of the project if adverse impacts to regulated wetlands, watercourses or
their buffers are identified.
D. Areas of Potential Geologic Instability.
1. Each development proposal for a legal lot of record containing an area of potential geologic
instability shall be subject to a geotechnical report pursuant to the requirements of Sections
18.45.060 and 18.45.080(6). The geotechnical report shall analyze and make
recommendations on the need for and width of any buffers necessary to achieve the goals
and requirements of this ordinance. Development proposals shall then include the buffer
distances as defined within the geotechnical report.
2. Buffers may be increased by the DCD Director when an area is determined to be particularly
sensitive to the disturbance created by a development. Such a decision will be based on a
City review of the report as prepared by a qualified geotechnical consultant and by a site
visit.
18.45.060 Procedures
General: When an applicant submits an application for any building permit, subdivision, short
subdivision or any other land use review which approves a use, development or future
construction, the location of any sensitive areas and buffers on the site shall be indicated on the
plans submitted. When a sensitive area is identified, the following procedures apply. The DCD
Director may waive item numbers 1, 4 and 5 of the following if the size and complexity of the
project does not warrant that step in the procedures.
1. Sensitive Areas Study and Geotechnical Report: The applicant shall submit the relevant
study as required in TMC 21.04.140 and this chapter.
It is intended that sensitive areas studies and information be utilized by applicants in
preparation of their proposals and therefore shall be undertaken early in the design stages of a
project.
2. Any new subdivision, short subdivision, boundary line adjustment, or multiple family
residential proposal which includes a sensitive area or its buffer on the site shall apply for a
Planned Residential Development permit and meet the requirements of Chapter 18.46 of
the Tukwila Zoning Code.
3. Denial of Use or Development: A use or development will be denied if it is determined by
the DCD Director that the applicant cannot ensure that potential dangers and costs to future
inhabitants of the development, adjacent and local properties, and Tukwila are minimized
and mitigated to an acceptable level.
4. Pre development Conference: The applicant, specialist(s) of record, contractor, and
Department representatives will be required to attend pre construction conferences prior to
any work on the site.
5. Construction Monitoring: The specialist(s) of record shall be retained to monitor the site
during construction.
6. The DCD Director may require the boundary between a sensitive area and its buffer and
any development or use to be permanently identified with fencing, or with a wood or
metal sign with treated wood, concrete or metal posts. Size will be determined at the time
of permitting, and wording shall be as follows:
"Protection of this natural area is in your care. Alteration or disturbance is prohibited
pursuant to TMC 18.45. Please call the City of Tukwila for more information."
18.45.080 Uses and Standards
A. General.
The following general uses may be located within a sensitive area or buffer, subject to the
provisions of TMC 21.04. Each permitted use is subject to the standards of this section.
Sensitive Areas Ordinance Page 10
1. Maintenance and repair of existing uses and facilities provided no alteration or additional fill
materials will be placed or heavy construction equipment used in the sensitive area or
buffer.
2. Non destructive education and research.
3. Passive recreation and open space.
4. Maintenance and repair of essential streets, roads, rights-of-way, or utilities.
5. Actions to remedy the effects of emergencies that threaten the public health, safety or
welfare.
6. Other uses may be allowed pursuant to TMC 18.45.080 B -H.
B. Permitted Uses Subject to Administrative Review.
The following uses may be permitted only after administrative review and approval by the DCD
Director.
1. Maintenance and repair of existing uses and facilities where alteration or additional fill
materials will be placed or heavy construction equipment used.
2. Construction of new essential streets and roads, rights -of -way and utilities.
3. New surface water discharges to wetlands or watercourses or their buffers from detention
facilities, pre settlement ponds, or other surface water management structures may be
allowed provided that the discharge meets the clean water standards of RCW 90.48 and
WAC 173.200 and 173.201 as amended, and does not increase the rate of flow to the
wetland or watercourse beyond the level of the existing rate.
4. Regional stormwater detention areas may be allowed if use results in no decrease in rating
of resource and enhances existing values and functions. Design shall be subject to the
standards of this section and other applicable City of Tukwila standards.
5. Enhancement or other mitigation including landscaping.
C. Wetlands.
1. General:
a. No use or development may occur in a Type 1 and Type 2 wetland or its buffer except
as specifically allowed by TMC 18.45.080 (A, B and H). Any use or development
allowed is subject to the standards of this section.
b. Only isolated Type 3 wetlands can be altered or relocated and then only with the
permission of the DCD Director. A mitigation or enhancement plan must be
developed and must comply with the standards of compensatory mitigation required
in this chapter.
c. Mitigation plans shall be completed for any proposals for dredging, filling, alterations,
and relocation of wetland habitat allowed in TMC 18.45.080 (A, B and H).
2. Compensatory Mitigation:
a. The mitigation plan shall be developed as part of a sensitive area study by a specialist
approved by the DCD Director. Wetland and /or buffer alteration or relocation may be
allowed only when a mitigation plan clearly demonstrates that the changes would be
an improvement of wetland and buffer quantitative and qualitative functions. The plan
shall follow the performance standards of this chapter and show how water quality,
wildlife and fish habitat, and general wetland quality would be improved.
b. In order to achieve the City's goal of no- net -loss of wetland functions and acreage,
alteration of wetlands will require the applicant to provide a restoration, enhancement
or creation plan to compensate for the impacts to the wetland and will compensate at a
ratio of 1.5:1.
c. Mitigation Location.
(1) On -site compensation shall be provided except where the applicant can
demonstrate that:
(a) the hydrology and ecosystem of the original wetland and those who benefit
from the hydrology and ecosystem will not be damaged by the on -site loss;
and
(b) on -site compensation is not scientifically feasible due to problems with
hydrology, soils, waves, or other factors, or
(c) compensation is not practical due to potentially adverse impact from
surrounding land uses; or
(d) existing functional values at the site of the proposed restoration are
significantly greater than lost wetland functional values; or
Sensitive Areas Ordinance Page 11
(e) that established regional goals for flood storage, flood conveyance, habitat or
other wetland functions have been established and strongly justify location
of compensatory measures at another site.
(2) Off -site compensation shall occur within the same watershed where the wet-
land loss occurred.
(3) In selecting compensation sites, applicants shall pursue siting in the following
order of preference:
(a) upland sites which were formerly wetlands;
(b) idled upland sites generally having bare ground or vegetative cover
consisting primarily of exotic introduced species, weeds, or emergent
vege tation;
(c) other disturbed upland.
d. Mitigation Standards:
The scope and content of a mitigation plan shall be decided on a case -by -case basis. As
the impacts to the sensitive area increase, the mitigation measures to offset these
impacts will increase in number and complexity. The components of a complete
wetlands mitigation plan are as follows:
(1) 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.
(2) 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 resource functions.
(3) Performance standards of the specific criteria for fulfilling environmental goals,
and for beginning remedial action or contingency measures. They may include
water quality standards, species richness and diversity targets, habitat diversity
indices, or other ecological, geological or hydrological criteria.
(4) Detailed construction plan of the written specifications and descriptions of mitiga-
tion techniques. This plan should include the proposed construction sequence
and construction management, and be accompanied by detailed site diagrams and
blueprints that are an integral requirement of any development proposal.
(5) Monitoring and /or evaluation program that outlines the approach for assessing a
completed project. An outline shall be included that spells out how the monitor-
ing data will be evaluated by agencies that are tracking the mitigation project's
progress.
(6) Contingency plan identifying potential courses of action, and any corrective mea-
sures to be taken when monitoring or evaluation indicates project performance
standards have not been met.
(7) Performance security or other assurance devices as described in TMC 18.45.135.
e. Mitigation Timing: Where feasible, compensatory mitigation projects shall be
completed prior to activities that will permanently disturb wetlands and immediately
after activities that will temporarily disturb wetlands. Construction of compensatory
projects shall be timed to reduce impacts to existing wildlife, flora and water quality,
and shall be completed prior to use or occupancy of the activity or development.
3. Essential Utilities
a. Essential utilities must be constructed to minimize or where possible avoid wetland
disturbance; and
b. All construction must be designed to protect the wetland and its buffer against erosion,
uncontrolled drainage, restriction of groundwater movement, slides, pollution, habitat
disturbance, any loss of flood carrying and storage capacity and excavation or fill
detrimental to the environment; and
c. Upon completion of installation of essential utilities, wetlands must be restored to pre
project configuration, replanted as required and provided with maintenance care until
newly planted vegetation is established; and
d. All crossings must be designed for shared facilities in order to minimize adverse
impacts and reduce the number of crossings.
4. Essential Streets, Roads and Rights -of -Way
a. Essential streets, roads and rights -of -way must be designed and maintained to prevent
erosion and avoid restricting the natural movement of groundwater; and
Sensitive Areas Ordinance Page 12
b. Essential streets, roads and rights-of-way must be located to conform to the topography
so that minimum alteration of natural conditions is necessary. The number of
crossings shall be limited to those necessary to provide essential access; and
c. Essential streets, roads and rights -of -way must be constructed in a way which does not
adversely affect the hydrologic quality of the wetland or interrelated stream habitat.
Where feasible, crossings must allow for combination with other essential utilities; and
d. Upon completion of construction, the area affected must be restored to an appropriate
grade, replanted according to a plan approved by the Director of DCD and provided with
care until newly planted vegetation is established.
5. Public Use and Access:
a. Public access shall be limited to trails, boardwalks, covered or uncovered viewing or
seating areas, and displays and must be located in areas which have the lowest
sensitivity to human disturbance or alteration; and
b. Public access must be specifically developed for interpretive, educational or research
purposes by, or in cooperation with, the City or as part of the adopted Tukwila Parks
and Open Space Plan; and
c. No motorized vehicle is allowed within a wetland or its buffer except as required for
necessary maintenance, agricultural management or security; and
d. Any public access or interpretive displays developed in a wetland and its buffer must,
to the extent possible, be connected with a park, recreation or open -space area; and
e. Vegetative edges, structural barriers, signs or other measures must be provided
wherever necessary to protect Sensitive Areas by limiting access to designated public
use or interpretive areas; and
f. Access trails must incorporate design features and materials which protect water
quality and allow adequate surface and ground water movement; and
g. Must be located where they do not disturb nesting, breeding, and rearing areas and
buffer areas, and must be designed so that sensitive plant and critical wildlife species
are protected.
6. Dredging, digging or filling:
a. Dredging, digging or filling within a wetland and its buffer may occur only with the
permission of the DCD Director and only for the following purposes:
(1) Uses permitted by Section 18.45.080A, B and H; or
(2) Maintenance of an existing wetland; or
(3) Enhancement or restoration of habitat in conformance with an approved
mitigation plan identified in a sensitive area study; or
(4) Natural system interpretation, education or research when undertaken by, or in
cooperation with, the City of Tukwila; or
(5) Flood control or water quality enhancement by the City of Tukwila; or
(6) Maintenance of existing water quality controls, for normal maintenance needs
and for any diversion, rerouting, piping, or other alteration permitted by this
chapter.
b. Any dredging, digging or filling shall be performed in a manner which will minimize
sedimentation in the water. Every effort will be made to perform such work at the
time of year when the impact can be lessened.
c. Upon completion of construction, the area affected must be restored to an appropriate
grade, replanted according to a plan approved by the Director of DCD and provided with
care until newly planted vegetation is established.
D. Watercourses.
1. General:
a. No use or development may occur in a watercourse or its buffer except as specifically
allowed by TMC 18.45 080. Any use or development allowed is subject to the
standards of this Section.
b. Diverting or rerouting may only occur with the permission of the DCD Director and an
approved mitigation plan.
c. Any watercourse which has critical wildlife habitat or is necessary for the life cycle or
spawning of salmonids, shall not be rerouted unless it can be shown that the habitat
will be improved for the benefit of the species.
Sensitive Areas Ordinance Page 13
d. Any watercourse which has no critical wildlife habitat may be rerouted if the waters
flowing from the new configuration can be shown to do so in a manner that does not
in any way adversely affect the habitat of a downstream salmonid bearing water.
2. Mitigation:
a. Mitigation plans shall be completed for any proposals of dredging, filling, diverting, and
rerouting of watercourses.
b. The mitigation plan shall be developed as part of a sensitive area study by a specialist
approved by the DCD Director. The plan must show how water quality, treatment,
erosion control, pollution reduction, wildlife and fish habitat, and general watercourse
quality would be maintained or improved. All such plans must be approved by the
DCD Director.
c. Mitigation Standards. The scope and content of a mitigation plan shall be decided on a
case -by -case basis. As the impacts to the sensitive area increase, the mitigation
measures to offset these impacts will increase in number and complexity. The
components of a complete mitigation plan are as follows:
(1) 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.
(2) 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 resource functions.
(3) Performance standards of the specific criteria for fulfilling environmental goals,
and for beginning remedial action or contingency measures. They may include
water quality standards, species richness and diversity targets, habitat diversity
indices, or other ecological, geological or hydrological criteria. The following shall
be considered the minimum performance standards for approved stream alter-
ations:
(a) Maintenance or improvement of stream channel dimensions, including the
components of depth, width, length and gradient of the original location;
(b) Bank and buffer configuration should be restored to an equal or enhanced
state of the original stream;
(c) The channel, bank and buffer areas shall be replanted with native
vegetation which replicates or improves the original in species, sizes and
densities.
(d) The stream channel bed and the biofiltration systems shall be equivalent to
or better than in the original stream.
(e) The original fish and wildlife habitat shall be maintained or enhanced.
(f) Relocation of a watercourse shall not result in the new sensitive area or
buffer extending beyond the development site and onto adjacent property
without the agreement of the affected property owners.
(g) A watercourse may be rerouted.
(4) Detailed construction plan of the written specifications and descriptions of mitiga-
tion techniques. This plan should include the proposed construction sequence
and construction management, and be accompanied by detailed site diagrams and
blueprints that are an integral requirement of any development proposal.
(5) Monitoring and /or evaluation program that outlines the approach for assessing a
completed project. An outline shall be included that spells out how the monitor-
ing data will be evaluated by agencies that are tracking the mitigation project's
progress.
(6) Contingency plan identifying potential courses of action, and any corrective mea-
sures to be taken when monitoring or evaluation indicates project performance
standards have not been met.
(7) Performance security or other assurance devices as described in TMC 18.45.135.
d. Mitigation Timing:
DCD approved plans must have the mitigation construction completed before the
existing watercourse can be modified.
3. Essential Utilities
a. Essential utilities must be constructed to minimize, or where possible avoid,
disturbance of the watercourse and its buffer; and
Sensitive Areas Ordinance Page 14
b. All construction must be designed to protect the watercourse and its buffer against
erosion, uncontrolled drainage, restriction of groundwater movement, slides, pollution,
habitat disturbance, any loss of flood carrying and storage capacity and excavation or fill
detrimental to the environment; and
c. Upon completion of installation of essential utilities, watercourses and their buffers
must be restored to pre project configuration, replanted as required and provided with
maintenance care until newly planted vegetation is established; and
d. All crossings must be designed for shared facilities in order to minimize adverse
impacts and reduce the number of crossings.
4. Essential Streets, Roads and Rights -of Way
a. Essential streets, roads and rights -of -way must be designed and maintained to prevent
erosion and avoid restricting the natural movement of groundwater; and
b. Essential streets, roads and rights-of-way must be located to conform to the topography
so that minimum alteration of natural conditions is necessary. The number of
crossings shall be limited to those necessary to provide essential access; and
c. Essential streets, roads and rights -of -way must be constructed in a way which does not
adversely affect the hydrologic quality of the watercourse and its buffer. Where
feasible, crossings must allow for combination with other essential utilities; and
d. Upon completion of construction, the area affected must be restored to an appropriate
grade, replanted according to a plan approved by the Director of DCD and provided with
care until newly planted vegetation is established.
5. Public Use and Access:
a. Public access shall be limited to trails, boardwalks, covered or uncovered viewing and
seating areas, and displays and must be located in areas which have the lowest
sensitivity to human disturbance or alteration; and
b. Public access must be specifically developed for interpretive, educational or research
purposes by, or in cooperation with, the City or as part of the adopted Tukwila Parks
and Open Space Plan; and
c. No motorized vehicle is allowed within a watercourse or its buffer except as required
for necessary maintenance, agricultural management or security; and
d. Any public access or interpretive displays developed along a watercourse and its buffer
must, to the extent possible, be connected with a park, recreation or open -space area;
and
e. Vegetative edges, structural barriers, signs or other measures must be provided
wherever necessary to protect watercourses and their buffers by limiting access to
designated public use or interpretive areas; and
f. Access trails must incorporate design features and materials which protect water
quality and allow adequate surface and ground water movement; and
g. 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.
6. Piping:
a. Piping of any watercourse should be avoided. Piping may be allowed in any
watercourse if it is necessary for access purposes. Piping may be allowed in Type III
watercourses if the applicant complies with the conditions of this section, including:
(1) excess capacity to meet needs of the system during a 1 00-year flood event, and
(2) flow restrictors, and water quality and existing habitat enhancement procedures.
b. No process that requires maintenance on a regular basis will be acceptable unless this
maintenance process is part of the regular and normal facilities' maintenance process or
unless the applicant can show funding for this maintenance is ensured; and
c. Piping in a watercourse sensitive area shall be limited and shall require approval of the
DCD Director. Piping projects shall be performed pursuant to the following applicable
standards:
(1) The conveyance system shall be designed to comply with the standards in
current use and recommended by the Department of Public Works.
(2) Where allowed, piping shall be limited to the shortest length possible as
determined by the Director of DCD to allow access onto a property.
(3) 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.
Sensitive Areas Ordinance Page 15
(4) When required by the Director of DCD, watercourses under drivable surfaces
shall be contained in an arch culvert using oversize or superspan culverts for
rebuilding of a stream bed. These shall be provided with check dams to reduce
flows, and shall be replanted and enhanced according to a plan approved by the
Director of DCD.
(5) When necessary to provide for fish passage, fish ladders shall be one foot vertical
rise to ten foot horizontal distance, or as approved by the Washington State
Department of Fisheries.
(6) Stormwater runoff shall be detained and infiltrated to preserve the watercourse
channel's dominant discharge.
(7) All construction shall be designed to have the least adverse impact on the
watercourse, buffer and surrounding environment.
(8) Piping shall be constructed during periods of low flow, or as specified by the State
Department of Fisheries.
(9) Water 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.
7. Dredging, digging or filling
a. Dredging, digging or filling within a watercourse or its buffer may occur only with the
permission of the DCD Director and only for the following purposes:
(1) Uses permitted by Section 18.45.080(1), (2) and (3); or
(2) Maintenance of an existing watercourse; or
(3) Enhancement or restoration of habitat in conformance with an approved
mitigation plan identified in a sensitive area study; or
(4) Natural system interpretation, education or research when undertaken by, or in
cooperation with, the City of Tukwila; or
(5) Flood control or water quality enhancement by the City of Tukwila; or
(6) Maintenance of existing water quality controls, for normal maintenance needs
and for any diversion, rerouting, piping, or other alteration permitted by this
chapter.
b. Any dredging, digging or filling shall be performed in a manner which will minimize
sedimentation in the water. Every effort will be made to perform such work at the
time of year when the impact can be lessened.
c. Upon completion of construction, the area affected must be restored to an appropriate
grade, replanted according to a plan approved by the Director of DCD and provided with
care until newly planted vegetation is established.
E. Areas of Potential Geologic Instability.
1. General: The uses permitted in the underlying zoning district may be undertaken on sites
which contain areas of potential geologic instability subject to the standards of this section
and the requirements of a geotechnical study.
2. Exemptions: Any temporary slope which has been created through legal grading activities
may be regraded without application of this chapter under an approved permit.
3. Alterations:
a. Prior to permitting alteration of an area of potential geologic instability, the applicant
must demonstrate one of the following:
(1) There is no evidence of past instability or earth movement in the vicinity of the
proposed development, and quantitative analysis of slope stability indicates no
significant risk to the proposed development or surrounding properties; or
(2) 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.
b. Where any portion of an area of potential geologic instability is cleared for development,
a landscaping plan for the site shall include tree re- planting with an equal mix of
evergreen and deciduous trees, preferably native, and approved by the Director of
DCD. Replacement vegetation shall be sufficient to provide erosion and stabilization
protection.
Sensitive Areas Ordinance Page 16
4. Geotechnical Report:
a. The applicant shall submit a Geotechnical Report appropriate to both the site conditions
and the proposed development. A geotechnical investigation shall be required for
development in Class 2, Class 3, Class 4 areas, and any areas identified as seismic or
coal mine hazard areas. This requirement may be waived by the Director of the
Department of Community Development for sites in Class 2 areas that are at least 200
feet from the nearest adjacent Class 3 or Class 4 hazard area, and which do not show
any erosion or sedimentation problems.
b. 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. Subsurface exploration of site conditions is at the discretion of
the geotechnical consultant.
c. 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, and a subsurface exploration of soils and hydrology
conditions. Detailed slope stability analysis shall be done if the geotechnical consultant
recommends it in Class 3 or Coal Mine Hazard areas, and must be done in all Class 4
areas.
d. Seismic hazard areas shall include an evaluation of site response and liquefaction
potential for the proposed development area. For one or two story single family
dwellings this evaluation may be based on the performance of similar structures under
similar foundation conditions. For proposed developments including occupied
structures other than one and two story single family dwellings, the evaluation shall
include sufficient subsurface exploration to provide a site coefficient (S) for use in the
static lateral force procedure described in the Uniform Building Code.
e. Applicants shall retain a Geotechnical Engineer to prepare the reports and evaluations
required in this Section. 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 appropriate City
department. Where appropriate, a Geologist must be included as part of the
geotechnical consulting team. The report shall make specific recommendations
concerning development of the site.
f. The geotechnical engineers required under this section must meet the qualification
standards approved by the Director of DCD. Applicants shall provide a list of
qualifications of the firm or individuals who will be doing the technical studies, and
those shall be approved by the Director of DCD. If the engineers' credentials are not
sufficient, the City may require applicants to use a different engineer or firm which
does meet the City's standards.
g. 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
Geologist.
h. An independent review of geotechnical reports will be required per TMC 21.04.140.
5. Disclosures, Declarations and Covenants.
a. It shall be the responsibility of the applicant to submit, consistent with the findings of
the geotechnical report, structural plans which 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 and that 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.
b. 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
Engineer who reviews the plans and specifications is not the same engineer who
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.
Sensitive Areas Ordinance Page 17
c. The Architect or Structural Engineer shall submit to the City, with the plans and
specifications, a letter of 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 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.
d. The applicant, or the owner of the site if the applicant is not the owner, shall submit a
letter to the City, with the plans and specifications, stating that he or she understands
and accepts the risk of developing in an area with potential unstable soils and that he or
she will advise, in writing, any prospective purchasers of the site, or any prospective
purchasers of structures or portions of a structure on the site, of the slide potential of the
area.
e. The owner shall execute a covenant, 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. This covenant shall include:
(1) The legal description of the Property;
(2) A statement explaining that the site is in an area of potential instability; of the risks
associated with development on the site, of any conditions or prohibitions on
development, and of any features in this design which will require maintenance
or modification to address anticipated soil changes;
(3) A statement waiving any claims the owner or his /her successors or assigns may
have against the City of Tukwila for any loss, or damage to people or property
either on or off the site resulting from soil movement arising out of the issuance
of any permit(s) authorizing development on the site;
(4) The date of issuance and number of the permit authorizing the development.
6. 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 DCD Director
may require assurance devices pursuant to Section 18.45.135.
7. Construction Monitoring:
a. 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 consultant 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.
b. 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 DCD Director.
8. Conditioning and Denial of Use or Developments:
a. 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.
b. 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.
Sensitive Areas Ordinance Page 18
A permit will be denied if it is determined by the DCD 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.
F. Abandoned Mine Areas.
1. Development of a legal lot of record containing an abandoned coal 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 DCD Director before any building or land altering permit
processes begin.
2 Any building setback or land alteration shall be based on the geotechnical report.
3. 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 to the
proposed development or adjacent properties.
G. Areas of important geological or archaeological evidence.
1. Development on a legal lot of record determined to have historic or prehistoric geological or
archaeological evidence, shall be prohibited until that evidence has been studied or
researched for any valuable information about our history. Removal or salvage of the
evidence shall be done in accordance with RCW 27.53, and shall be performed in a timely
manner.
2. Once the geologic or archaeological evidence or articles have been studied or researched, or
the importance of the site is declared to be marginal or not of use to the scientific
community, development shall be allowed on the site. Development shall not begin on
such a site until the DCD Director gives approval.
H. Permitted Uses Subject to Exception Approval.
Other uses may be permitted upon receiving a reasonable use exception pursuant to TMC
18.45.115. A use permitted through a reasonable use exception shall conform to the procedures
of this chapter and be consistent with the underlying zoning.
18.45.090 Sensitive Areas Tracts
A. In development proposals for planned residential or mixed area use developments, short
subdivisions or subdivisions, boundary line adjustments and binding site plans, applicants shall
create sensitive areas tracts, in lieu of an open space tract, per the standards of TMC 18.46.080.
B. Applicants proposing development, involving uses other than those listed in TMC 18.45.090A, on
parcels with sensitive areas or their buffers, may elect to establish a sensitive area tract which
shall be:
1. If under one ownership, owned and maintained by the ownership, which assures the
protection of the tract; or
2. Held in common ownership by multiple owners who shall collectively be responsible for
maintenance of the tract; or
3. Dedicated for public use if acceptable to the City or other appropriate public agency.
18.45.115 Exceptions
A. General.
With the approval of the Director of DCD, isolated wetlands that are 400 square feet or smaller in
area, and which are low value according to the rating methodology used in the City's Water
Resource Rating and Buffer Study, may not require the compensatory mitigation standards of this
chapter.
B. Piping.
Piping will be allowed in Type 1 and Type 2 watercourses only where relocation or alteration of
a watercourse is denied and would result in denial of all reasonable use.
C. Reasonable Use Exceptions.
1. If application of this Chapter would deny all reasonable use of the property containing
wetlands, watercourses or their buffers, the property owner or the proponent of a
development proposal may apply for a reasonable use exception.
2. The application for a reasonable use exception shall be in a format specified by and filed with
the Department of Community Development. Requirements may include an
environmental impact statement pursuant to Washington Administrative Code 197 -11 -400.
Sensitive Areas Ordinance Page 19
Reasonable use exceptions shall be decided by the Planning Commission following a public
hearing noticed as specified in 18.92.
3. If the applicant demonstrates to the satisfaction of the Planning Commission that application
of this Chapter would deny all reasonable use of the property, development may be
allowed which is consistent with the general purposes of this ordinance and the public
interest.
4. The Commission, in granting approval of the reasonable use exception, must determine
that:
a. No reasonable use with less impact on the sensitive area and its buffer is possible;
b. There is no feasible on -site alternative to the proposed activities, including reduction in
size or density, phasing of project implementation, change in timing activities, revision
of road and lot layout, and /or related site planning activities that would allow a
reasonable economic use with fewer adverse impacts to the sensitive area and its
buffer;
c. As a result of the proposed development there will be no increased or unreasonable
threat of damage to off -site public or private property and no threat to the public health,
safety or welfare on or off the development proposal site;
d. Alterations permitted shall be the minimum necessary to allow for reasonable use of
the property;
e. 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;
f. Disturbance of sensitive areas has been minimized by locating the necessary
alterations in the buffers to the greatest extent possible;
g. The inability to derive reasonable use of the property is not the result of actions by the
applicant in segregating or dividing the property and creating the undevelopable
condition after the effective date of this Chapter; and
h. Any approved alteration of a sensitive area under this section shall be subject to
conditions as established by this chapter and will require mitigation under an approved
mitigation plan. If a development is approved as a reasonable use, Board of
Architectural process, review and standards shall be applied.
18.45.120 Variances
A. The Board of Adjustment shall review requests pursuant to TMC 18.72 for variance from the
standards of this chapter unless excepted by Section 18.45.115.
B. If a variance is granted, it shall be the minimum necessary to accommodate the permitted uses of
the underlying zoning district, proposed by the application and the scale of the use may be
reduced as necessary to meet this requirement.
18.45.125 Appeals
A. Any aggrieved party who objects to or disagrees with Department of Community Development
decisions or conditions for development in a sensitive area, shall appeal to the Planning
Commission. Any such appeal shall be made in writing within ten days of the interpretation,
condition or decision being appealed, and shall set forth the basis for the appeal.
B. In considering appeals of decisions or conditions, the following shall be considered:
1. The intent and purposes of the sensitive areas ordinance;
2. Technical information and reports considered by the Department of Community
Development; and
3. Findings of the DCD Director shall be given substantial weight.
18.45.130 Recording Required
The property owner receiving approval of a use or development pursuant to this chapter shall
record the City- approved site plan clearly delineating the wetland, watercourse, areas of potential
geologic instability or abandoned mine and their buffer designated by section 18.45.020 and
18.45.040 with the King County Division of Records and Election. The face of the site plan must
include a statement that the provision of this chapter, as now or hereafter amended, control use
and development of the subject property and provide for any responsibility of the property owner
for the maintenance or correction of any latent defects or deficiencies.
18.45.135 Assurance Device
A. In appropriate circumstances, the Department of Community Development Director may require
a letter of credit or other security device acceptable to the City, to guarantee performance and
maintenance requirements of this Chapter. All assurances shall be on a form approved by the
City Attorney.
Sensitive Areas Ordinance Page 20
B. When alteration of a sensitive area is approved, the Director of the Department of Community
Development may require an assurance device, on a form approved by the City Attorney, to
cover the monitoring costs and correction of possible deficiencies. Monitoring of alterations may
be required for up to five (5) years.
C. Release of the security does not absolve the property owner of responsibility for maintenance or
correcting latent defects or deficiencies.
18.45.140 Assessment Relief
A. Fair Market Value. The King County Assessor shall consider sensitive area regulations in
determining the fair market value of land under RCW 84.34.
B. Current Use Assessment. Established sensitive area tracts, as defined in TMC 18.06.698 and
provided for in TMC 18.45.090, shall 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 TMC Chapter 18.46.
C. Special Assessments. Landowners who qualify under Section 18.45 140B shall also be exempted
from special assessments on the sensitive area tract to defray the cost of municipal improvements
such as sanitary sewers, storm sewers and water mains.
SECTION 4. ORDINANCE NOS. 1247 AND 1249 AND TMC 18.46 AMENDED. TMC 18.46
is hereby amended as follows:
1. TMC 18.46.010 is hereby amended to read in its entirety as follows:
18.46.010 Purpose.
It is the purpose of this chapter to encourage imaginative site and building design and to create
open space in residential developments by permitting greater flexibility in zoning requirements
than is permitted by other sections of this title. Furthermore, it is the purpose of this chapter to:
1. Promote the retention of significant features of the natural environment, including
topography, vegetation, watercourses, wetlands, and views;
2. Encourage a variety or mixture of housing types;
3. Encourage maximum efficiency in the layout of streets, utility networks, and other public
improvements; and
4. Create and /or preserve usable open space for the enjoyment of the occupants and the
general public.
2. TMC 18.46.030 is hereby amended to read in its entirety as follows:
18.46.030 Permitted uses.
The following uses are allowed in planned residential development:
1. In R -1 districts, dwellings may be permitted which are harmonious with the surrounding
residential character and built environment. Single unit detached dwellings will be
preferable to attached units; however, attached two -unit dwellings will be considered if
necessary to accommodate interior zero lot lines for projects with sensitive areas and /or
sensitive area buffers.
2. In R -2, R -3, R -4, and RMH districts, residential developments of all types regardless of the
type of building in which such residence is located, such as single family residences,
duplexes, triplexes, fourplexes, rowhouses, townhouses or apartments; provided, that all
residences are intended for permanent occupancy by their owners or tenants. Hotels,
motels, and travel trailers and mobile homes and trailer parks are excluded;
3. Accessory uses specifically designed to meet the needs of the residents of the PRD such as
garages and recreation facilities of a noncommercial nature;
4. In planned residential developments of ten acres or more, commercial uses may be
permitted. Commercial uses shall be limited to those which are of a neighborhood
convenience nature such as beauty or barber shops, drugstores, grocery stores and self
service laundries.
3. TMC 18.46.040 is hereby amended to read in its entirety as follows:
18.46.040 Site acreage minimum.
The minimum site for a planned residential development shall be one acre, except sites con-
taining sensitive areas and their buffers.
Sensitive Areas Ordinance Page 21
4. TMC 18.46.050 is hereby repealed
S. TMC 18.46.060 is hereby amended to read in its entirety as follows:
18.46.060 Relationship of this chapter to other sections and other ordinances.
A. 1. Lot Size. The minimum lot size provisions of other sections of this code are waived within
the planned residential development. The number of dwelling units per net acre permitted
in the underlying zone shall serve as the criteria to determine basic PRD density.
2. Building Height. Building heights may be modified within a PRD when it assists in
maintaining natural resources, significant vegetation, and enhances views within the site
without interfering with the views of adjoining property. For increases in building height,
there shall be a commensurate decrease in impervious surface.
3. Setbacks. Yard requirements of TMC. 18.50 shall be waived within the PRD; however,
setbacks and design of the perimeter of the PRD shall be comparable to or compatible with
the bulk and streetscape of the existing development of adjacent properties or the type of
development which may be permitted.
B. Off Street Parking.
Off- street parking shall be provided in a PRD in the same ratio for types of buildings and uses as
required in Chapter 18.56. However, for multiple family zoned sites with sensitive areas, a
minimum of 2 parking stalls per unit will be allowed, with a 50% compact stalls allowance, and
parking stalls in front of carports or garages will be allowed if the design does not affect circulation.
C. Platting Requirements.
The standards of the subdivision code for residential subdivisions shall apply to planned
residential developments if such standards are not in conflict with the provisions of this chapter.
Upon final approval of the PRD, filing of the PRD shall be in accordance with procedures of the
subdivision code if any lots are to be transferred.
D. Impervious Surface.
The maximum amount of impervious surface calculated for the total development allowed on
sensitive areas sites will be 50% for each single family development and each multi- family
development.
E. Recreation Space Requirements.
Sensitive areas and stands of significant trees may be counted as area required to meet the
recreation space minimums if usable passive recreation opportunities within these areas are
demonstrated. Opportunities could include connection and continuation of area -wide trail
systems, wildlife or scenic viewing opportunities, or picnic areas.
F. Landscape and Site Treatment for Sites with Class 2, Class 3 and Class 4 Geologic Hazard Areas.
1. Down slope and side yard buffers Elevations and off -site perspectives shall show
minimum landscape coverage of 25% of the structures at time of project completion with
anticipated 40% coverage within 15 years. This standard may supplement or be in lieu of
the applicable landscape yard requirement.
2. Any road or access drive which cuts approximately perpendicular to a slope to the ridgeline
of a hill shall have minimum five foot planted medians. The tree shall be a species that
provides a branch pattern sufficient to provide at maturity, 50 coverage of the pavement
area. Roads or drives which require retaining walls parallel to the topographic line shall plant
roadside buffers of northwest native plant species.
G. The Board of Architectural Review shall review guidelines for single- and multi- family
developments. The design and review of the PRD shall also utilize the guidelines of TMC
18.60.050.
H. For single family developments, the site plans shall include placement and footprint of the
residences, driveways and roads.
6. TMC 18.46.070 is hereby amended to read in its entirety as follows:
18.46.070 Density standards.
A. The basic density shall be the same as permitted by the underlying zone district. The dwelling
units per net acre for the residential zones are as provided in Chapter 18.50.
B. Single family.
1. In R -1 single family residential districts, the planning commission may recommend, and the
City Council may authorize, a minimum lot size not less than the yard requirements of the
Sensitive Areas Ordinance Page 22
R -1 -7.2 district following findings that the amenities or design features listed in subsections a.
through d. of 18.46.070B.2. below are substantially provided.
2. In R -1 single family residential districts on sites containing sensitive areas or their buffers, the
planning commission may recommend, and the City Council may authorize, a minimum
lot size less than the yard requirements of the R -1 -7.2 district following findings that the
amenities or design features listed below in subsections a. through d. are substantially
provided:
a. At least fifteen percent of the natural vegetation is retained (in cases where significant
stands exist); and
b. Advantage or enhancement is taken of unusual or significant site features such as
views, watercourses, or other natural characteristics; and
c. Separation of auto and pedestrian movement, especially in or near areas of recreation;
and
d. Development aspects of the PRD complement the land use policies of the compre-
hensive plan.
C. In multiple family residential districts, the planning commission may recommend, and the City
Council may authorize, a dwelling unit density not more than twenty percent greater than
permitted by the underlying zones or an increase equal to the allowable density credits as set
forth in 18.46.070(D), if the site contains sensitive areas or buffers following findings that the
amenities or design features listed below are substantially provided:
1. A variety of housing types are offered;
2. At least fifteen percent of the natural vegetation is retained (in cases where significant stands
exist);
3. Advantage is taken or enhancement is achieved of unusual or significant site features such
as views, watercourses, wetlands or other natural characteristics;
4. Separation of auto and pedestrian movement, especially in or near areas of recreation; and
5. Developmental aspects of the PRD complement the land use policies of the comprehensive
plan.
D. Density Transfer
1. Density transfers are intended to provide for the protection of wetlands, watercourses, and
associated buffers while allowing development which is consistent with existing zoning to
the greatest extent possible.
2. Density transfers are the percentage credits to be used in calculating the number of dwelling
units for a residential site containing undevelopable sensitive areas or buffers.
The calculation of the maximum units per buildable acre of a site with protected areas shall
be equal to: (DU Dwelling Units)
[(DU /acre)(Buildable Acres)] [(DU /acre)(Sensitive Areas and Buffer)(Density Transfer)]
3. Density transfer credits shall be determined from the table below:
PERCENTAGE OF SITE IN DENSITY
SENSITIVE AREAS BUFFER TRANSFER
1 10 30%
11 20 27%
21 -30 24%
31 -40 21%
41 50 18%
51 60 15%
61 70 12%
71 -80 9%
81 -90 6%
91 -100 3%
4. The density transfer can only be used within the development proposal site. Any such
modifications shall be reviewed and approved through the site development process in
TMC 18.60.
5. Development of the transferred density shall be confined to buildable areas of the site, and
shall not intrude on sensitive areas or their buffers.
Sensitive Areas Ordinance Page 23
7. TMC 18.46.080 is hereby amended to read in its entirety as follows:
18.46.080 Open space.
A. Each planned residential development shall provide not less than twenty percent of the gross site
area for common open space which shall:
1. Provide either passive or active recreation concentrated in large usable areas; and
2. Network with the trail and open space system of the city and provide a connection and
extension, if feasible;
3. Be under one ownership, owned and maintained by the ownership; or be held in common
ownership by all of the owners of the development by means of a home owners or similar
association. Such association shall be responsible for maintenance of the common open
space; or be dedicated for public use, if acceptable to the city or other appropriate public
agency.
B. Planned residential developments shall set aside sensitive areas and their buffers in a sensitive
areas tract as required by Chapter 18.45.090, and will be exempted from other open space
requirements of this section.
8. TMC 18.46.090 is hereby amended to read in its entirety as follows:
18.46.090 Relationship to adjacent areas.
A. The design and layout of a planned residential development shall take into account the integration
and compatibility of the site to the surrounding areas. The perimeter of the PRD shall be so
designed as to minimize any undesirable impact of the PRD on adjacent properties.
B. Setbacks from the property lines of the PRD shall be comparable to or compatible with, those of
the existing development of adjacent properties or, if adjacent properties are undeveloped the
type of development which may be permitted.
9. TMC 18.46.110 is hereby amended to read in its entirety as follows:
18.46.110 Application procedure required for PRD approval.
A. Filing of Application.
Application for approval of the PRD shall be made on forms prescribed by the Department of
Community Development and shall be accompanied by a filing fee as required in Chapter 18.88
and by the following:
1. Justification for the density bonus, if requested by the applicant,
2. Program for development including staging or timing of development,
3. Proposed ownership pattern upon completion of the project,
4. Basic content of any restrictive covenants,
5. Provisions to assure permanence and maintenance of common open space through a home
owners association, or similar association, condominium development or other means
acceptable to the city;
6. An application for rezone may be submitted with the PRD application if rezoning is
necessary for proposed density. Fees for rezone request shall be in addition to those of the
PRD application;
7. An application for preliminary plat may be submitted with the PRD application, if necessary.
Fees for the subdivision shall be in addition to those of the PRD application.
8. Graphic images of development in any sensitive area or buffer, including photo- montage or
computer generated perspectives in a standardized format required by the Director of the
Department of Community Development.
9. Every reasonable effort shall be made to preserve existing trees and vegetation and integrate
them into the subdivision's design by preparing a tree inventory of the significant vegetation
on site as part of the preliminary plat application. A tree and vegetation retention/removal
plan shall be part of any preliminary plat application. Such tree and vegetation
retention/removal plan shall assure the preservation of significant trees and vegetation.
B. Planning Commission Public Hearing.
The planning commission shall hold at least one public hearing on the proposed PRD, and shall
give notice thereof pursuant to Chapter 18.92 of this title. The public hearing shall not be held
before completion of all necessary and appropriate review by city departments. This review shall
be completed within a reasonable period of time.
Sensitive Areas Ordinance Page 24
C. Planning Commission Recommendation.
Following the public hearing, the planning commission shall make a report of its findings and
recommendations with respect to the proposed PRD and the criteria of this chapter and forward
the report to the City Council.
D. City Council Public Hearing.
1. After receipt of the planning commission report, the City Council shall hold a public hearing
on the proposed PRD as recommended by the planning commission. The City Council
shall give approval, approval with modifications, or disapproval to the proposed PRD.
2. The PRD shall be an exception to the regulations of the underlying zoning district. The PRD
shall constitute a limitation on the use and design of the site unless modified by ordinance.
10. TMC 18.46.112 is hereby amended to read in its entirety as follows:
18.46.112 Review criteria.
The Planning Commission and City Council shall find that the proposed development plans meet
all of the following criteria in their decision making.
1. Requirements of the subdivision code for the proposed development have been met, if
appropriate;
2. Reasons for density bonuses meet the criteria as listed in Section 18.46.070;
3. Adverse environmental impacts have been mitigated;
4. Compliance of the proposed PRD to the provisions of this chapter and Chapter 18.45;
5. Time limitations, if any, for the entire development and specified stages have been
documented in the application;
6. Development in accordance with the comprehensive land use policy plan and other
relevant plans;
7. Compliance with the BAR review guidelines (TMC 18.60.050);' and
8. Appropriate retention and preservation of existing trees and vegetation recommended by the
Director of Community Development.
11. TMC 18.46.120 is hereby amended to read in its entirety as follows:
18.46.120 Application procedures for building permit.
The following procedures are required for approval of construction for the proposed planned
residential development:
1. Time Limitation. A complete application for the initial building permit shall be filed by the
applicant within twelve months of the date on which the City Council approved the PRD.
An extension of time for submitting an application may be requested in writing by the
applicant, and an extension not exceeding six months may be granted by the Director of
DCD. If application for the initial building permit is not made within twelve months or
within the time for which an extension has been granted, the plan shall be considered
abandoned, and the development of the property shall be subject to the requirements and
limitations of the underlying zone and the subdivision code.
2. Application. Application for building permit shall be made on forms prescribed by the DCD
and shall be accompanied by a fee as prescribed by the building code.
3. Documentation Required. All schematic plans either presented or required in the approved
PRD plans shall be included in the building permit application presented in finalized, detailed
form. These plans shall include but are not limited to landscape, utility, open space,
circulation, and site or subdivision plans. Final plats and public dedication documents must
be approved by the City Council before the issuance of any building permits.
4. Sureties Required for Staging. If the PRD is to be developed in stages, sureties, or other
security device as shall be approved by the City Attorney, shall be required for the complete
PRD. The various stages or parts of the PRD shall provide the same proportion of open space
and the same overall dwelling unit density as provided in the final plan.
5. Department of Community Development Action. The Department of Community
Development shall determine whether the project plans submitted with the building permit
are in compliance with and carry out the objectives of the approved PRD. Following
approval of the DCD, the city clerk shall file a copy of the approved PRD plan with the official
records of the city and the originals shall be recorded with the King County department of
records and elections. After all approvals, the official zoning map shall be amended to reflect
the PRD by adding the suffix "PRD" to the designation of the underlying zone.
Sensitive Areas Ordinance Page 25
SECTION 5. ORDINANCE NO. 1247 AND TMC 18.70.050 AMENDED. TMC 18.70.050 is
hereby amended to add subsections (6) and (7) as follows:
(6) In wetlands, watercourses and their buffers, existing structures that do not meet the requirements of
Chapter 18.45 may be remodeled, reconstructed or replaced, provided that:
(a) the new construction does not further intrude into or adversely impact an undeveloped sensitive
area or the required buffer; and
(b) the new construction does not threaten the public health, safety or welfare, and
(c) the structure otherwise meets the requirements of this chapter.
(7) In areas of potential geologic instability, coal mine hazard areas, and buffers, as defined in TMC 18.45,
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
18.45.080E and F; and
(b) the new construction does not threaten the public health, safety or welfare; and
(c) the new construction does not increase the potential for soil 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.
SECTION 6. ORDINANCE NO. 1014 AND TMC TITLE 17 AMENDED.
1. TMC 1Z08.030 is hereby amended to read in its entirety as follows:
17.08.030 Principles of acceptability.
The following principles shall determine the acceptability of boundary line adjustments and short
subdivisions:
1. Create legal building sites with respect to zoning and health regulations;
2. Establish access to a public road for each segregated parcel;
3. If adjacent to another municipality or King County, take into consideration the subdivision
standards of that jurisdiction, as well as the requirements of this code;
4. Make adequate provision for: drainage ways, streets, alleys, other public ways, water
supplies and sanitary wastes, as deemed necessary.
5. Comply with Chapter 17.20, Design standards for the subdivision of land, and Chapters
17.24 and Chapter 17.28 Minimum standards for Residential and Commercial Subdivision
Design, respectively.
6. Actions by the applicant to get a boundary line adjustment or short subdivision shall not
result in the inability to derive reasonable economic use of the property or create an
undevelopable lot under Chapter 18.45.115 unless that lot is to be dedicated for exclusive
use as open space or common tract.
2. TMC 1Z08.040 is hereby amended to read in its entirety as follows:
17.08.040 Application requirements.
A. Application for a short subdivision shall be made with the Department of Community
Development on forms prescribed by that office. Said application shall be accompanied by ten
copies of the short subdivision plat.
B. If the subject site is within the sensitive area overlay zone, administrative review and approval of
a Planned Residential Development (PRD) shall be required for the proposed short subdivision
and boundary line adjustment. The standards and criteria for PRD design and review are those
listed in TMC 18.46. The procedure shall be those listed in 17.08.060.
C. The short subdivision plat and boundary line adjustment shall conform to the following
requirements:
1. Shall be a neat and accurate drawing by a land surveyor on reproducible material at a
decimal scale. The plat map shall measure between eight and one -half inches by eleven
inches and eight and one -half inches by fourteen inches.
2. Shall show how the proposed subdivision will be served by streets and utilities.
3. Each application shall be accompanied by a preliminary title report dated within thirty
calendar days of the submission date.
Sensitive Areas Ordinance Page 26
3. TMC 17.08.060 is hereby amended to read in its entirety as follows:
17.08.060 Review Procedures.
A. Referral to Other Departments.
Upon receipt of an application for a short subdivision, the planning division of the Department of
Community Development shall transmit one copy of the application to each member of the short
subdivision committee, and one copy to any department or agency deemed necessary. The
application shall be transmitted at least five working days prior to the short subdivision committee
meeting.
B. Notice to adjacent property owners.
If a PRD is being processed as part of the short plat application per 17.08.040 (b), notice shall be
mailed to all property owners within 300 feet, fifteen days prior to the Short Subdivision
Committee meeting, notifying them of the pending proposal and requesting comments.
C. Short Subdivision Committee. The short subdivision committee shall consist of the director of
the office of community development, who shall be chairman; the public works director; and the
fire chief; or their designated representatives.
D. Short Subdivision Committee Meeting. A meeting of the short subdivision committee, attended
by the applicant at his option, shall be held no later than twenty calendar days from receipt of a
complete application. Said meeting shall be open to the public.
1. Quorum. All members of the short subdivision committee or their representative must be
present in order for action to be taken.
2. Action. The short subdivision committee may approve, approve with modifications, or
deny the application for a short subdivision. The decision of the short subdivision
committee shall be made at the meeting and the applicant notified in writing of such
decision within three working days. An additional meeting may be called if a decision is not
reached at the first meeting. The second meeting should be no later than seven days after
the first meeting. An applicant may request to have an application on which the short
subdivision committee has taken action reopened by the committee if it is found by the
director of the office of community development and the applicant that new information has
come to light that might affect the action taken by the short subdivision committee.
3. Appeal. The decision of the short subdivision committee shall.be final, unless an appeal by
any aggrieved party is made to the planning commission within ten calendar days of the
date of decision of the short subdivision committee. Said appeal shall be in writing to the
planning commission and filed with the office of community development. The planning
commission shall act on said appeal within forty calendar days unless an extension thereto
is agreed to, in writing, by the applicant. The decision of the planning commission shall be
final and conclusive unless, within ten calendar days, any aggrieved party files with the city
clerk a written appeal addressed to the City Council. The City Council shall act on said
appeal within twenty days of the date of appeal.
4. TMC 17.12.030(a) and (b) are hereby amended to read in their entirety as follows:
17.12.030 Preliminary plat procedures.
(a) Application.
(1) Application for a preliminary plat shall be filed with the planning division on forms
prescribed by that office. A complete application must be filed at least thirty calendar days
prior to the date of the planning commission meeting at which it is to be considered.
(2) The application shall be accompanied by a fee of eight hundred dollars plus seventy -five
dollars for each proposed lot.
(3) At least five copies of the preliminary plat shall be submitted, which shall be prepared by a
land surveyor.
(4) Fifteen copies of the preliminary plat, photographically reduced to eight and one -half inches
by eleven inches or eight and one -half inches by fourteen inches, shall accompany the
application.
(5) A list of the names and addresses of all owners of record of property within three hundred
feet of the external boundaries of the proposed subdivision.
(6) Environmental information shall be prepared and submitted in accordance with the
guidelines established under the State Environmental Policy Act of 1971, as amended, Title
21 of this code, as amended, and the Sensitive Areas Overlay District, as amended in Title
18.45 of this code, as may be amended thereafter. Said information is a part of and must
accompany the preliminary plat application.
Sensitive Areas Ordinance Page 27
(b) Preliminary Plat Requirements.
The following shall be part of the preliminary plat:
(1) Vicinity Map. Adequate to readily identify the location of the plat in relation to its
surrounding vicinity.
(2) Preliminary Plat. The preliminary plat shall include all of the following:
(A) The subdivision name and number, and the name and address of the land surveyor;
(B) The date of preparation, the true north point, a graphic scale and legal description of the
property proposed for subdivision. Plats shall be drawn to an appropriate engineering
(decimal) scale;
(C) All existing conditions shall be delineated. The location, width and names of all
existing or prior platted streets or other public open spaces, permanent buildings and
structures, and section and municipal corporation lines within or adjacent to the
property proposed for subdivision shall be shown. In the case of a resubdivision, the
lots, blocks, streets, alleys, easements and parks of the original subdivision being
vacated, shall be shown by dotted lines in their proper position in relation to the new
arrangement of the subdivision; the new subdivision being clearly depicted in solid
lines so as to avoid ambiguity. Existing sewer and water lines, culverts, or other
underground facilities within the property proposed for subdivision indicating pipe
sizes, grades and exact location as obtained from public records shall be shown.
Boundary lines of adjacent lands, whether subdivided or unsubdivided shall be
indicated by dotted lines for a distance of three hundred feet from the external
boundary of the property proposed for subdivision and shall include the existing land
use classification.
(D) A survey of existing trees and vegetation with a retention /removal plan which
assures the preservation of significant trees and vegetation.
(E) Existing contours (solid) and proposed contours (dotted) at intervals of five feet or less
and referenced to the United States Coast and Geodetic Survey (USC GS) datum. All
contour lines shall be extended at least one hundred feet beyond the external
boundaries of the property proposed for subdivision;
(F) The names, locations, widths, and other dimensions of proposed streets, alleys,
easements, parks and other open spaces, reservations, and utilities together with the
purpose and any conditions or limitations of such reservations clearly indicated;
(G) Clearly indicate the source of water supply, method of sewage disposal, and manner of
surface runoff control;
(H) Indicate the approximate dimensions of each lot and all lot and block numbers;
(I) Indicate the acreage of land to be subdivided, the number of lots and the area of the
smallest lot;
5. TMC 17.20.010 is hereby amended to read in its entirety as follows:
17.20.010 Purpose.
It is the purpose of this chapter to provide for the protection of valuable, irreplaceable envi-
ronmental amenities and to make urban development as compatible as possible with the
ecological balance of the area. Goals are to preserve sensitive areas and their buffers, protect
groundwater supply, prevent erosion, and to preserve trees, vegetation, and drainage patterns.
These are beneficial to the city in lessening the costs of development to the city as a whole, to the
subdivider in creating an attractive and quality environment, and in attainment of the goals and
objectives of the Tukwila comprehensive land use policy plan.
6. TMC 17.20.020 is hereby amended to read in its entirety as follows:
17.20.020 Environmental considerations.
A. Unsuitable Land.
Land which meets the definition of a sensitive area or its buffer as defined in TMC 18 or is subject
to the Flood Zone Control Ordinance as defined in TMC 16.52, shall be platted to reflect the
standards and requirements of the Sensitive Areas Overlay zone, TMC 18.45, 18.46, the Planned
Residential Development, and the Flood Zone Control Ordinance, TMC 16.52.
B. Trees.
Every reasonable effort shall be made to preserve existing trees and vegetation and integrate them
into the subdivision's design by preparing a tree inventory of the significant vegetation on site as
part of the preliminary plat application.
Sensitive Areas Ordinance Page 28
7. TMC 1720.040 is hereby amended to read in its entirety as follows:
17.20.040 Grading.
Prior to any grading within a proposed or approved subdivision, a land alteration permit shall be
obtained in accordance with the provisions of Chapter 70 of the Uniform Building Code.
8. TMC 17.20.050 is hereby amended to read in its entirety as follows:
17.20.050 Streets.
A. Extension.
Proposed street systems shall extend existing streets at the same or greater width, unless
otherwise approved by the department of public works and authorized by the City Council in
approval of the plat. Where appropriate, streets shall be extended to the boundaries of the plat to
insure access to neighboring properties. The City's goal is to have an integrated system of local
streets rather than a system of cul -de -sacs. Grading of steep topography may be necessary to
achieve this objective. However, in sensitive areas, the layout and construction of streets shall
follow the standards and procedures of the sensitive areas overlay zone.
B. Names.
All proposed street names or numbers shall be subject to approval by the Department of
community development.
C. Intersections.
Any intersection of public streets, whatever the classification, shall be at right angles as nearly as
possible and not be offset insofar as practical.
9. TMC 17.24,020 is hereby amended to read in its entirety as follows:
17.24.020 Street layout.
Street layout shall provide for the most advantageous development of the subdivision, adjoining
areas, and the entire neighborhood. Evaluation of street layout shall take into consideration
potential circulation solutions. While it is important to minimize the impact to the topography
from creating an integrated road system, improved site development and circulation solutions
shall not be sacrificed to minimize the amount of cut and fill requirements of the proposal. Where
sensitive areas are impacted, the standards and procedures for rights-of-way in the sensitive areas
overlay zone shall be followed.
10. TMC 17.24.040 is hereby amended to read in its entirety as follows:
1724.040 Public rights -of -way.
A. Right -of -way Width.
Street widths may vary according to function, traffic generated and topography. The following
minimum street widths for streets, as defined in the Tukwila comprehensive land use policy
plan, shall apply unless otherwise approved by the department of public works and authorized
by the City Council in approval of the preliminary plat or by the short subdivision committee in
the case of short plats.
TYPE OF STREET RIGHT -OF -WAY PAVEMENT
Major Arterial 80 feet 60 feet
Secondary Arterial 75 feet 48 feet
Collector 60 feet 36 feet
Local Street 50 feet 30 feet
Cul -De -Sac
Roadway 40 feet 26 feet
Turnaround 80 feet diameter 60 feet diameter
Alley 20 feet 15 feet
Right -of -way may be reduced to 40 feet with five foot easements on each side if the subject
roadway will be traversing or adjacent to wetlands and watercourses.
B. Design.
The design and alignment of all public streets shall conform to the following standards unless
otherwise approved by the department of public works:
Sensitive Areas Ordinance Page 29
1. Street Intersection Offsets. Where street intersections must be offset, such offsets shall not
measure less than two hundred fifty feet from centerline to centerline.
2. Cul -de -sacs. Cul -de -sacs shall not exceed a length of six hundred feet unless authorized in
accordance with Section 17.32.010.
3. Street Grades. Street grades shall not exceed 15 percent. However, provided there are no
vehicular access points, grades may be allowed up to 18 percent, for not more than 200 feet
when:
a. exceeding the grades would facilitate a through street and connection with the larger
neighborhood; and
b. the greater grade would minimize disturbance of sensitive slopes;and
c. the Fire Marshal grants approval.
4. Tangents. Minimum tangents shall conform to department of public works standards.
5. Horizontal Curves. Minimum curve radii shall conform to department of public works
standards.
6. Vertical Curves. Changes in grade shall conform to department of public works standards.
C. Right -of -way Improvement.
All right -of -way improvements shall conform to department of public works standards.
D. Utilities.
All utilities designed to serve the subdivision shall be placed underground and, if located within a
sensitive area, shall be designed to meet the standards of the sensitive areas overlay zone. Those
utilities to be located beneath paved surfaces shall be installed, including all service connections,
as approved by the department of public works; such installation shall be completed and approved
prior to application of any surface materials.
1. Sanitary Sewers: Unless septic tanks are specifically approved by the appropriate health
agencies, sanitary sewers shall be provided at no cost to the city and designed in accordance
with city standards.
2. Storm Drainage: An adequate drainage system shall be provided for the proper drainage of all
surface water; the amount of runoff shall be determined by the rational method. Cross
drains shall be provided to accommodate all water flow and shall be of sufficient length to
permit full width roadway and required slopes. The diameter to be provided shall be
determined by Manning's Equation, but in no case shall the inner diameter be less than
twelve inches.
3. Water System: The water distribution system including the locations of fire hydrants shall
be designed and installed in accordance with city standards.
E. Public Use and Service Areas.
1. Due consideration shall be given by the subdivider to the allocation of adequately sized areas
for public service or usage.
2. Easements. Easements may be required for the maintenance and operation of utilities as
specified by the public works department.
F. Blocks.
1. Length. Blocks should not be less than three hundred feet nor more than one thousand feet
in length. Where circumstances warrant, the planning commission may require one or
more public pathways of not less than six feet nor more than fifteen feet in width dedicated
in the city to extend entirely across the width of the block at locations deemed necessary.
2. Width. Blocks shall be wide enough to allow two tiers of lots, except where abutting a
major street or prevented by topographical conditions or size of the property, in which case
the planning commission may approve a single tier.
G. Lots.
1. Arrangement. Insofar as practical, side lot lines shall be at right angles to street lines or radial
to curved street lines. Each lot must have access to a public street that is approved at the
time of plat review; however rather than designing flag lots, access shall be accomplished
with common drive easements. Location of yards shall reflect the prevailing pattern within
the neighborhood. For example, if adjacent developed lots front on the street the
subdivision's lots fronting the street should also establish front yards for those lots.
2. Minimum Size. The size, shape, and orientation of lots shall meet or exceed the minimum
area and width requirements of the applicable zoning classification and shall be appropriate
for the type of development and use contemplated.
Sensitive Areas Ordinance Page 30
3. Corner Lots. Corner lots may be required to be platted with additional width to allow for the
additional side yard requirements.
4. Through Lots. Residential through lots are not encouraged and shall only be approved if
there is a topographic or traffic safety concern preventing double tiered lots. Approved
through lots shall be permitted access to only one street, unless otherwise approved by the
department of public works and shall provide a fifteen foot rear yard buffer of native
vegetation.
5. Property Corners at Intersections. All lot corners at intersections of dedicated public rights -of-
way shall have a minimum radius of twenty -five feet.
H. Trees.
Each lot within a new subdivision shall be landscaped with at least one tree in the front yard to
create a uniform streetscape. Installation shall be required per 17.12.040(3)
I. Other Improvements.
1. Monuments.
a. Concrete permanent control monuments shall be established at each and every
controlling corner of the subdivision. Interior monuments shall be located as
determined by the department of public works.
b. All other lot corners shall be marked with suitable metal or wood markers.
2. Street Signs. The subdivider shall be responsible for the initial cost of any street name or
number signs, or street markings, including installation thereof, necessary in the subdivision
as required by the department of public works.
SECTION 7. ORDINANCE NOS. 1331 AND 1344 AND TMC 21.04 AMENDED.
1. TMC 21.04.040 is hereby amended to read in its entirety as follows:
21.04.040 Definitions Additional.
In addition to those definitions contained within WAC 197 -11 -700 through 799, when used in this
chapter the following terms shall have the following meanings, unless the content indicates
otherwise:
1. "Department" means any division, subdivision or organizational unit of the city established
by ordinance, rule or order.
2. "Early notice" means the city's response to an applicant stating whether it considers
issuance of the determination of significance likely for the applicant's proposal.
3. "Environmentally sensitive area" see 21.04.300.
4. "Notice of action" means the notice of the time for commencing an appeal of a SEPA
determination that the city or the applicant may give following final city action upon an
application for a permit or approval when said permit or approval does not have a time
period set by statute or ordinance for commencing an appeal.
5. "Official notice" means the notice that the city shall give of the date and place for
commencing an appeal of final city action upon an application for a permit or approval where
said permit or approval has a time period set by statute or ordinance for commencing appeal.
6. "SEPA Rules" means WAC Chapter 197 -11 adopted by the Department of Ecology.
2. TMC 21.04.130 is hereby amended to read in its entirety as follows:
21.04.130 Threshold determination Review at conceptual stage.
A. If the city's only action on a proposal is a decision on a building permit or other license that
requires detailed project plans and specifications, the applicant may request in writing that the city
conduct environmental review prior to submission of the detailed plans and specifications.
B. In addition to the environmental documents an applicant may be required to submit the
following information:
1. Conceptual site plans and building plans;
2. Other information as the responsible official may determine.
3. Environmentally sensitive areas studies as described in TMC 21.04.140 for sensitive areas.
Sensitive Areas Ordinance Page 31
3. TMC 21.04.140 is hereby amended to read in its entirety as follows:
21.04.140 Threshold determinations -Environmental checklist.
A. A completed environmental checklist shall be filed at the same time as an application for a permit,
license, certificate or other approval not exempted by this chapter. The checklist shall be in the
form of WAC 197 -11 -960 with the following additions:
1. If the site is an environmentally sensitive area, a sensitive area study that meets the
requirements of the SEPA official may be required. The SEPA official may waive any study
requirements determined to be unnecessary for review of a particular use or application.
Environmentally sensitive area studies shall have three components: a site analysis, an
impact analysis, and proposed mitigation measures. More or less detail may be required for
each component depending on the size of the project, severity of potential impacts, and
availability of information. Funding for a qualified professional, selected and retained by the
City shall be paid for by the applicant, to review the geotechnical reports on Class 2 and 3
Landslide, Seismic and Coal Mine Hazard areas if the geotechnical report indicates Class 3 or
4 characteristics; and will be required in all Class 4 Landslide Hazard areas.
2. Identification of conflicts with the policies of the comprehensive land use policy plan and
proposed measures to reduce the conflicts;
3. Description of the objectives of the proposal, the alternative means of accomplishing these
objectives, comparison of the alternatives and indication of the preferred course of action.
B. A checklist is not needed if the city and the applicant agree an EIS is required, SEPA compliance
has been completed, or SEPA compliance has been initiated by another agency.
C. The city shall use the environmental checklist to determine the lead agency and, if the city is the
lead agency, for making the threshold determination.
D. For private proposals, the applicant is required to complete the environmental checklist. The city
may provide information as necessary. For city proposals, the department initiating the proposal
shall complete the environmental checklist for that proposal.
E. The city may decide to complete all or part of the environmental checklist for a private proposal, if
either of the following occurs:
1. The city has technical information on a question or questions that is unavailable to the
private applicant; or
2. The applicant has provided inaccurate information on previous proposals or on proposals
currently under consideration.
4. TMC 21.04.150 is hereby amended to read in its entirety as follows:
21.04.150 Threshold determinations Mitigated DNS.
A. The responsible official may issue a determination of nonsignificance (DNS) based on conditions
attached to the proposal by the responsible official or on changes to, or clarifications of, the proposal
made by the applicant.
B. An applicant may request in writing early notice of whether a Determination of Significance (DS)
is likely. The request must:
1. Follow submission of a permit application and environmental checklist for a nonexempt
proposal for which the department is lead agency; and
2. Precede the city's actual threshold determination for the proposal.
C. The responsible official's written response to the request for early notice shall:
1. State whether the city currently considers issuance of a DS likely and, if so, indicate the
general or specific areas of concern that are leading the city to consider a DS; and
2. State that the applicant may change or clarify the proposal to mitigate the indicated impacts,
and may revise the environmental checklist and /or permit application as necessary to
reflect the changes or clarifications.
D. When an applicant submits a changed or clarified proposal, along with a revised environmental
checklist, the city shall base its threshold determination on the changed or clarified proposal.
1. If the city indicated specific mitigation measures in its response to the request for early
notice, and the applicant changed or clarified the proposal to include those specific mitigation
measures, the city shall issue and circulate a determination of nonsignificance if the city
determines that no additional information or mitigation measures are required.
2. If the city indicated areas of concern, but did not indicate specific mitigation measures that
would allow it to issue a DNS, the city shall make the threshold determination, issuing a
DNS or DS as appropriate.
Sensitive Areas Ordinance Page 32
3. The applicant's proposed mitigation measures, clarifications, changes or conditions must be
in writing and must be specific.
4. Mitigation measures which justify issuance of a mitigated DNS may be incorporated in the
DNS by reference to agency staff reports, studies or other documents.
E. The city shall not act upon a proposal for which a mitigated DNS has been issued for fifteen days
after the date of issuance.
F. Mitigation measures incorporated in the mitigated DNS shall be deemed conditions of approval of
the licensing decision and may be enforced in the same manner as any term or condition of the
permit or enforced in any manner specifically prescribed by the city. Failure to comply with the
designated mitigation measures shall be grounds for suspension and /or revocation of any license
issued.
G. If the city's tentative decision on a permit or approval does not include mitigation measures that
were incorporated in a mitigation DNS for the proposal, the city should evaluate the threshold
determination to assure consistency with WAC 197- 11- 340(3)(a) relating to the withdrawal of a
DNS.
H. The city's written response under subsection (c) of this section shall not be construed as a
determination of significance. In addition, preliminary discussion of clarification or changes to a
proposal, as opposed to a written request for early notice, shall not bind the city to consider the
clarifications or changes in its threshold determination.
5. TMC 21.04.270 is hereby amended to read in its entirety as follows:
21.04.270 SEPA Policies.
A. The policies and goals set forth in this chapter are supplementary to those in the existing
authorization of the city.
B. The city adopts by reference the policies in the following city codes, ordinances, resolutions and
plans as now existing or as may be amended hereafter:
1. Zoning Code -TMC Chapter 18;
2. Shoreline Master Plan Ordinance 898;
3. Comprehensive Land Use Policy Plan- Ordinance 1246;
4. Long Range Parks and Open Space Plan Ordinance 1315;
5. Subdivision Ordinance -TMC Chapter 17.04;
6. Comprehensive Sewer Plan Resolution 904;
7. Comprehensive Water Plan- Resolution 873;
9. Uniform Building Code -1982 Edition- Ordinance 1287;
9. Transportation Improvement Plan Resolution 917;
10. Annexation Policy Plan Resolution 626;
11. Sidewalk Ordinance Ordinance 1233;
12. Standard Specifications for Municipal Construction Ordinance 1250.
6. TMC 21.04.300 is hereby amended to read in its entirety as follows:
21.04.300 Environmentally sensitive areas.
A. Environmentally sensitive areas designated on the zoning maps and /or as defined in Zoning
Code TMC 18.06 and pursuant to 18.45.020 or hereinafter amended, designate the locations of
environmentally sensitive areas within the city and are adopted by reference. In addition to
those areas identified in WAC 197 -11 -908 and for purposes of this chapter environmentally
sensitive areas shall also include wooded hillsides, and the Green /Duwamish River and its
shoreline zone as defined by the Tukwila Master Program. For each environmentally sensitive
area, the categorical exemptions within WAC 197 -11 -800 that are inapplicable for these areas are:
WAC 197 -11- 800(1), (2)(a) through (h), (3), (5), (6)(a), (14(c), (24)(a) through (g), and (25)(d), (f),
(h) and (i). Unidentified exemptions shall continue to apply within environmentally sensitive
areas of the city.
B. The city shall treat proposals located wholly or partially within an environmentally sensitive area
no differently than other proposals under this chapter, making a threshold determination for all
such proposals. The city shall not automatically require an EIS for a proposal merely because it is
proposed for location in an environmentally sensitive area.
C. Certain exemptions do not apply on lands covered by water, and this remains true regardless of
whether or not lands covered by water are mapped.
Sensitive Areas Ordinance Page 33
SECTION 8. SEVERABILITY. If any portion of this Ordinance, as now or hereafter amended, its
application to any person or circumstances is held invalid or unconstitutional, such adjudication shall not
affect the validity of the Ordinance as a whole, or any section, provision, or part thereof not adjudicated to be
invalid or unconstitutional and its application to other persons or circumstances shall not be affected.
SECTION 9. EFFECTIVE DATE. This Ordinance shall take effect five (5) days from the date of
publication of the attached summary which is hereby approved.
PASSED BY THE CITYUNCIL OF THE CITY OF TUKWILA, WASHINGTON, at a Regular Meeting
thereof this /D day o /,-i -e 1991.
In accordance with RCW 35A.12.130 this
ordinance shall become valid without
the Mayor's approval.
Gary L. Van Dusen, Mayor
ATTEST /AUTHENTICATED:
Jane E. Cantu, City Clerk
APPROVED AS TO FORM:
OFFICE OF THE CITY ATTORNEY:
Bv: �l��t t I 7/
FILED WITH THE CITY CLERK: 1 /o— 9/
PASSED BY THE CITY COUNCIL: 6
PUBLISHED: 6 3 77
EFFECTIVE DATE: j a 8 9`
ORDINANCE NO.:
SUMMARY OF ORDINANCE NO.
AN ORDINANCE OF THE CITY OF TUKWILA, WASHINGTON,
REGULATING DEVELOPMENT ON SENSITIVE AREAS AND
BUFFERS; AMENDING ORDINANCE NOS 1247 AND 1289 AND
TUKWILA MUNICIPAL CODE (TMC) TITLE 18; AMENDING
ORDINANCE NOS. 1331 AND 1334 AND TMC TITLE 21.04;
AMENDING ORDINANCE NO 1014 AND TMC TITLE 17; AND
PROVIDING FOR AN EFFECTIVE DATE.
On the City Council of the City of Tukwila passed Ordinance
No. /A"99' providing for the regulation of development on sensitive areas and their
buffers; amending Tukwila Municipal Code Titles 17, 18 and 21; and providing for severability
and an effective date.
The full text of this ordinance will be mailed without charge to anyone who submits a
written request to the City Clerk of the City of Tukwila for a copy of the text.
APPROVED by the City Council at its meeting of irk 9 9/
0
e E. Cantu, City Clerk
Published Valley Daily News: —/3 9