HomeMy WebLinkAboutSR_ERC_Report_Harmony_Ridge_231025_FINALDEPARTMENT OF COMMUNITY
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SR_ERC_Report_Harmony_Ridge_231023_FINAL
ENVIRONMENTAL REVIEW COMMITTEE REPORT
ERC Meeting Date: October 30, 2023
Project File Number: PR23-000076
Project Name: Harmony Ridge
Land Use File Number: LUA23-000143, ECF, PP, LLA, MOD
Project Manager: Alex Morganroth, Senior Planner
Owner: United Christian Church, 15509 116th Ave SE, Renton, WA 98058
Contact: Ivana Halverson, Barghuasen Engineering, 18215 72nd Ave S, Kent, WA 98032
Applicant: Kanon Kupferer, Ichijo USA Co., Ltd, Bellevue, WA 98007
Project Location: 15509 116th Ave SE (2023059067)
Project Summary: The applicant is requesting Preliminary Plat approval, Environmental (SEPA) Review, a lot line
adjustment, and a street modification for a phased subdivision project consisting of 22 total lots,
including 21 lots intended for new single-family homes and one lot reserved for the existing church,
school, and associated surface parking currently developed on the site. The subject parcel is located at
15509 116th Ave SE (APN 2023059067) and is approximately 6.27 acres in size. The site has a
Comprehensive Plan Land Use Designation of Residential Medium Density (MD) and a zoning
designation of Residential-8 (R-8) dwelling units per net acre (du/ac). The applicant is proposing a
phased subdivision. Phase 1 of the subdivision would separate the church, school and associated
parking from the rest of the site by creating a new 46,129 sq. ft. lot. The remaining portion of the parent
site would total approximately 226,988 sq. ft. in area and would be subdivided into 21 new single-
family lots as part of Phase 2. The individual single-family lots would range in size from 5,001 to 5,866
sq. ft. The proposal also includes four (4) tracts including three (3) tree retention tracts and one
stormwater tract to be created during Phase 2 of the subdivision. Access to the lots is proposed via
two (2) new public residential access streets (Road A and Road B) off of 116th Ave SE, including a cul-
de-sac. Only Road A would have direct access to 116th Ave SE. Twelve of the lots would utilize a new
public alley off of Road A. Street frontage improvements are proposed along the entire length of the
site fronting 116th Ave SE, including in front of the future church parcel. The applicant has proposed
the retention of 63 trees out of the 404 trees located on the site. According to COR Maps, a moderate
coal mine hazard and sensitive slopes hazard are located on the site. The applicant submitted a traffic
impact analysis, a drainage report, a geotechnical report, a wetland reconnaissance study, an arborist
report, and an Environmental Checklist with the application.
Exist. Bldg. Area SF: 199,168 Proposed New Bldg. Area (footprint):
Proposed New Bldg. Area (gross):
N/A
N/A
Site Area: 6.5 acres Total Building Area GSF: 206,730
STAFF
RECOMMENDATION:
Staff Recommends that the Environmental Review Committee issue a Determination
of Non-Significance (DNS).
DocuSign Envelope ID: 88ED493A-1813-4C83-AC0E-63CD05982755
City of Renton Department of Community & Economic Development
Harmony Ridge
Staff Report to the Environmental Review Committee
LUA23-000143, ECF, PP, LLA, MOD
Report of October 30, 2023 Page 2 of 7
SR_ERC_Report_Harmony_Ridge_231025_FINAL
ENVIRONMENTAL REVIEW
In compliance with RCW 43.21C.240, the following environmental (SEPA) review addresses only those project impacts
that are not adequately addressed under existing development standards and environmental regulations.
A. Environmental Threshold Recommendation
Based on analysis of probable impacts from the proposal, staff recommends that the Responsible Officials:
Issue a DNS with a 14-day appeal period
B. Mitigation Measures
None recommended
C. Exhibits
Exhibit 1: Environmental Review Committee (ERC) Report
Exhibit 2: SEPA Checklist
Exhibit 3: Site Plan
Exhibit 4: Plan Drawings (Drainage, Utility, Landscape)
Exhibit 5: Topography Map
Exhibit 6: Arborist Report, prepared by Washington Forestry Consultants, Inc, dated January 24,
2023
Exhibit 7: Tree Retention Worksheet
Exhibit 8: Geotechnical Engineering Study, prepared by Earth Solutions NW, LLC, dated November
21, 2022, updated July 3, 2023
Exhibit 9: Preliminary Technical Information Report, prepared by Barghausen Engineers, dated
February 2, 2023
Exhibit 10: Wetland Reconnaissance, prepared by Altmann Oliver Associates, dated August 5, 2021
Exhibit 11: Traffic Impact Analysis, prepared by Transportation Engineering Northwest (TENW),
dated December 5, 2022
Exhibit 12: Transportation Concurrency Memo
Exhibit 13: Advisory Notes
Exhibit 14: Offsite Arborist Report, prepared by Washington Forestry Consultants, Inc, dated August
7, 2023
D. Environmental Impacts
The Proposal was circulated and reviewed by various City Departments and Divisions to determine whether the
applicant has adequately identified and addressed environmental impacts anticipated to occur in conjunction with
the proposed development. Staff reviewers have identified that the proposal is likely to have the following probable
impacts:
1. Earth
Impacts: According to COR Maps, a high seismic hazard, a moderate coal mine hazard, and sensitive slopes
are located on the project site. As such, the applicant submitted a Geotechnical Engineering Study,
prepared by Earth Solutions NW, LLC and dated November 21, 2022 and updated July 3, 2023 with the
project application (Exhibit 8). Per the report, no sensitive slopes were fou nd on the site, however
DocuSign Envelope ID: 88ED493A-1813-4C83-AC0E-63CD05982755
City of Renton Department of Community & Economic Development
Harmony Ridge
Staff Report to the Environmental Review Committee
LUA23-000143, ECF, PP, LLA, MOD
Report of October 30, 2023 Page 3 of 7
SR_ERC_Report_Harmony_Ridge_231025_FINAL
sensitive slopes were found along the proposed utility connection on the City’s Rolling Hills site to the
west. The topography of the site generally descends to the south and southwest, with a maximum
elevation change of approximately 25 feet across the site. According to the submitted geotechnical report,
the site is underlain by Alderwood gravelly sandy loam, a soil associated with ridges and hills and is derived
from glacial drift. In October of 2022, 12 test pits were excavated with a mini-trackhoe. The test pits
ranged in depth from approximately eight (8) to 14 feet. During testing, the geotechnical engineer
encountered six to twelve inches (6” – 12”) of topsoil underlain by silty sand with some gravel. Variations
in soil gradation were observed in some test pits and included areas of increased gravel, silt, and sand
contents. Soils within the upper approximate three to five feet (3’ – 5’) of existing grades were generally
characterized as medium dense, after which native soils become dense to very dense. Groundwater was
not encountered within the explored depths of the test pit locations.
According to the report, on-site Alderwood series (AgC) soils are considered to have a moderate erosion
potential. As such, the site may be considered to possess a low erosion hazard due slopes being less than
15% across the site. The report contends that typical best management practices (BMPs) and permanent
landscaping installations can successfully mitigate any potential soil erosion both duri ng and after
construction. In addition, COR Maps indicates the subject site is within a moderate coal mine hazard (CM)
area. Per RMC 4-3-050.G.5.e.ii, coalmine hazard areas are defined as areas where mine workings are
deeper than 200 feet for steeply dipping seams, or deeper than 15 times the thickness of the seam or
workings for gently dipping seams. The report contends that after analysis, construction of the proposed
residential development is not expected to increase the potential for ground subsidence on the subject
site and therefore no buffers or setbacks from the coalmine hazard are recommended.
The report concludes that the proposed single-family residences can be supported on conventional spread
footings bearing on competent native soil, recompacted native soil, or structural fill. If unsuitable soils are
encountered, they should be over excavated and backfilled with structural fill. Full infiltration is de emed
infeasible due to the wide-spread prevalence of glacially consolidated soils. However, the report contends
that small-scale BMP or LID designs may be viable for the project depending on the final grading plan.
Recommendations were included in the report regarding site preparation, temporary and permanent
erosion control, foundation design, wet weather construction, retaining walls, slab on grade construction,
stormwater management and utilities. It is anticipated that the City’s adopted erosion contro l measures
would adequately mitigate any potential adverse impacts that could occur during project construction. In
addition, the project would be required to demonstrate compliance with the structural design
requirements in the 2018 International Building Code for sites with seismic hazards upon building permit
application submittal. Therefore no specific mitigation measures are recommended.
Mitigation Measures: None recommended.
2. Air
Impacts: It is anticipated that some temporary air quality impacts could be associated with site work and
building construction required to develop this site. Project development impacts during construction may
include dust as a result of grading and exhaust from construction vehicles and equipment. Dust control
would be mitigated through the use of temporary erosion control measures, watering or other measures
to remediate impacts as needed. Long term emissions from vehicles owned by residents and delivery
companies would occur following project completion.
No further site-specific mitigation for the identified impacts from typical vehicle and construction exhaust
is required.
Mitigation Measures: None recommended.
Nexus: Not applicable.
DocuSign Envelope ID: 88ED493A-1813-4C83-AC0E-63CD05982755
City of Renton Department of Community & Economic Development
Harmony Ridge
Staff Report to the Environmental Review Committee
LUA23-000143, ECF, PP, LLA, MOD
Report of October 30, 2023 Page 4 of 7
SR_ERC_Report_Harmony_Ridge_231025_FINAL
3. Water
Stormwater
Impacts: The applicant submitted a Preliminary Technical Information Report, prepared by Barghausen
Engineers, dated February 2, 2023 (Exhibit 9) and preliminary drainage plan (Exhibit 4, Sheet 4). Based on
the City of Renton’s flow control map, the site falls within the Flow Control Duration Standard – Matching
Forested. The site falls within two (2) drainage basins including the Lower Cedar River Drainage Basin
(Ginger Creek sub-basin on the northeast portion of the site and the Black River Basin (Thunder Hills Creek
sub-basin) on the southwest portion of the site. The project will have one (1) discharge location from the
proposed stormwater vault to the City’s conveyance system in Puget Dr SE.
The majority of stormwater runoff from the site sheet flows towards the southwest and enters the existing
conveyance system within the Rolling Hills Village plat to the southwest. From there, runoff flows west
for approximately 550 feet and enters the conveyance system on Puget Dr SE and eventually flows into
Thunder Hills Creek. A smaller portion of the site consisting of the existing church buildings, parking lot
and frontage improvements on the north side of the site flows to the northeast and is tributary to the
Ginger Creek sub basin (identified as Lot 22).
Due to the water from the project site entering two (2) distinct basins (Black River and Lower Cedar River),
the TIR includes separate analysis related to each basin (identified as Predeveloped Basin 1 and
Predeveloped Basin 2). Predeveloped Basin 1, which flows to the Black River Drainage Basin, will include
the runoff from the existing United Christin Church building and all future impervious surfaces associated
with the subdivision development. Predeveloped Basin 2, which flows to the Lower Cedar River Drainage
Basin, will only include runoff from the frontage improvements to be installed directly in front of the
church site (identified as Lot 22). The project is required to provide a flow control and a water quality
facility for the proposed development in Predeveloped Basin 1, as the proposed improvements would
include more than 5,000 square feet of new plus replaced pollution generating impervious surface. One
stormwater vault is proposed to mitigate flow control and water quality impacts in Predeveloped Basin 1.
The vault would be located in the stormwater tract (Tract A) on the west side of the project site. The
improvements proposed in Predeveloped Basin 2 are exempt flow control requirements since the peak
flow produced by the 100-year storm event does not increase by more than 0.15 cfs. The improvements
are also exempt from providing water quality treatment as they will not result in more than 5,000 sq. ft.
of pollution generating impervious surfaces.
Improvements required for the conveyance from the stormwater vault to the discharge location in Puget
Dr SE includes a new 12-inch surface water main extending across the City of Renton-owned site (Rolling
Hills Reservoir) to the northwest of the project. The applicant is required provide documentation from
City of Renton approving the construction of the proposed 12-inch surface water main, catch basins, and
associated access road within City’s property prior to issuance of a civil construction permit.
Project construction is required to comply with the 2022 Renton Surface Water Design Manual (RSWDM).
The TIR submitted is based on a full drainage review as required in the 2022 Renton Surface Water Design
Manual. Core requirements one through nine, as well as the six special requirements, have been discussed
in the Technical Information Report. All requirements would be addressed in the final TIR submitted and
reviewed with the civil construction permit application.
A Construction Stormwater General Permit from Department of Ecology is required since grad ing and
clearing of the site exceeds one (1) acre. A Stormwater Pollution Prevention Plan (SWPPP) is also required
for this site. The development would be subject to stormwater system development charges. It is
anticipated that the requirements set forth by the 2022 City of Renton Surface Water Design Manual
(2022 RSWDM), or a future stormwater manual adopted by the City of Renton, would be sufficient to
DocuSign Envelope ID: 88ED493A-1813-4C83-AC0E-63CD05982755
City of Renton Department of Community & Economic Development
Harmony Ridge
Staff Report to the Environmental Review Committee
LUA23-000143, ECF, PP, LLA, MOD
Report of October 30, 2023 Page 5 of 7
SR_ERC_Report_Harmony_Ridge_231025_FINAL
mitigate stormwater impacts generated by the proposed development and no specific mitigation
measures are recommended.
Mitigation Measures: None recommended.
Nexus: Not applicable.
4. Environmental Health
a. Noise
Impacts: Noise impacts would primarily result from the construction of the proposed road improvements
and new structure and addition. The construction noise would be regulated through the City’s adopted
noise level regulations per Chapter 8-7, RMC. The City’s noise regulations limit haul hours between 8:30
am to 3:30 pm, Monday through Friday unless otherwise approved by the Development Services Division.
Permitted work hours in or near residential areas are restricted to the hours between seven o’clock (7:00)
a.m. and eight o’clock (8:00) p.m. for multi -family construction activities from Monday through Friday.
Work on Saturdays is restricted to the hours between nine o’clock (9:00) a.m. and eight o’clock (8:00) p.m.
No work is permitted on Sunday. Therefore, no significant impacts are anticipated and no specific
mitigation measures are recommended.
Mitigation Measures: None recommended.
Nexus: Not applicable.
5. Vegetation
Impacts: The applicant submitted two (2) Arborist Reports prepared by Washington Forestry Consultants,
Inc. The first report, dated January 24, 2023 (Exhibit 6), evaluates trees proposed for retention and
removal on the site. The second report, dated August 7, 2023, evaluates off-site trees proposed for
removal on the City-owned site to the west (Rolling Hills Reservoir) as a result of the proposed utility
connections and associated access road the applicant is requesting approval to construct.
According to the first Arborist Report submitted by the applicant (Exhibit 6), which evaluates the project’s
on-site trees, the site is currently vegetated with 404 significant trees of which 29 are designated High
Risk and 67 are located in the proposed ROW. After the deduction of the trees within the proposed right-
of-way and those determined high-risk, the site would have 309 trees viable for retention. The applicant
is proposing to retain 63 significant trees, or twenty percent (20%) of the onsite significant trees (Exhibit
7). All retained trees on the future subdivision site would be located within one of the three tree tracts
(Tract A, C, and D) proposed on the site. The proposal will be required to comply with the City’s adopted
Tree Retention and Land Clearing Regulations and Landscaping Regulations which would include the
retention and/or replacement of at least 30 percent (30%) of onsite significant trees, the verification that
each new lot would provide the required 10 feet (10’) of onsite landscaping along all public street
frontages, landscaping of the proposed stormwater tract, and the planting of street trees within all public
rights-of-way. It is anticipated that compliance with the City’s adopted Tree Retention and Land Cl earing
Regulations and Landscaping Regulations would adequately mitigate for the removal of existing trees on
the project site, therefore no further mitigation for the on-site vegetation impacts is recommended at this
time.
The second Arborist Report submitted by the applicant (Exhibit 14), which evaluates the off-site trees on
the city-owned Rolling Hills Reservoir site, the utility extension would result in the removal of 57 significant
trees. Of the 57 trees, eleven trees were classified as High Risk, re sulting in 46 viable trees. Due to the
heavily forested nature of the Rolling Hills site, the report only evaluated trees within the 38-foot wide
construction area where the utilities would be installed connecting the subdivision site to the existing
utilities in the Puget Dr SE ROW. As part of the formal agreement with the City for the construction of
utilities on city-owned property, which is currently under negotiation, the applicant would be required to
comply with the City’s adopted Tree Retention and Land Clearing Regulations and Landscaping
DocuSign Envelope ID: 88ED493A-1813-4C83-AC0E-63CD05982755
City of Renton Department of Community & Economic Development
Harmony Ridge
Staff Report to the Environmental Review Committee
LUA23-000143, ECF, PP, LLA, MOD
Report of October 30, 2023 Page 6 of 7
SR_ERC_Report_Harmony_Ridge_231025_FINAL
Regulations and may be subject to additional mitigation for the loss of trees on the site. Therefore, no
further mitigation for the off-site vegetation impacts is recommended at this time.
6. Transportation
Impacts: The proposed project fronts 116th Ave SE along the eastern property line. 116th Ave SE is classified
as a Minor Arterial Street and has an existing right-of-way (ROW) of approximately 30 feet. The proposed
development would be required to construct frontage improvements, including paving, curb and gutter,
planter strip with street trees and a sidewalk along 116th Ave SE, including in front of both the church site
and the subdivision site. To meet the City’s complete street standards for minor arterial stree ts, a
minimum ROW width of 91 feet is required. Dedication of approximately 30.5 feet of ROW would be
required, but would need to vary due to the misaligned ROW in front of the site . Complete street
improvements required for 116th Ave SE include a pavement width of 54 feet (27 feet from centerline, 2-
11-ft travel lanes, plus a 5-ft bike lane), a 0.5-ft curb, an 8-ft planting strip, an 8-ft sidewalk, street trees
and storm drainage improvements. However, the City’s Transportation Department has established an
alternative corridor plan for the section of 116th Ave SE adjacent to the project site. The corridor plan
would require a right-of-way width of 71-ft with a paved roadway section of 44-ft (two 11-ft travel lanes,
one 12-ft center turn lane, and two 5-ft bike lanes), a 0.5-ft vertical curb, 8-ft planter, 5-ft sidewalk, street
trees, and storm drainage improvements along each side of the roadway. The submitted preliminary
roadway improvement plan (Exhibit 4, Sheet 6) depicts variable ROW dedication range from 5.5’ to 12.9’
ROW and street improvements along 116th Ave SE following the requirement above , which staff finds
conceptually acceptable.
The project proposes to construct residential streets (identified as Road A and Road B) onsite with direct
access to 116th Ave SE. In addition, the applicant has proposed an alley (identified as Alley Z) to provide
access to proposed lots 1 through 12. To meet the City’s complete street standards for Residential Access
streets, a minimum ROW width of 53 feet is required for both Road A and Road B. Per RMC 4-6-060, the
residential street section shall include a minimum 26-foot paved road (13-foot on each side), 0.5 feet of
cubs, an 8-foot planting strip, and 5-foot sidewalk, street trees and storm drainage improvements on both
sides of the street. The alley shall provide a minimum pavement width of 12-feet with two-feet of clear
space on each side.
A Traffic Impact Analysis (TIA) is required when a project proposal would result in the generation of 20
new a.m. or p.m. peak hour trips. A TIA prepared by Transportation Engineering Northwest (TENW) and
dated December 5, 2022 (Exhibit 11) and submitted with the land use application. According to the TIA,
the proposed project is estimated to generate 240 new weekday daily trips, with 18 new trips occurring
during the weekday AM peak hour (5 in, 13 out), and 23 new trips occurring during the weekday PM peak
hour (14 in, 9 out). The calculation is based on the ITE Manual for Trip Generation, 11th Editi on. The TIA
discussed traffic impacts at a future year of 2024 and evaluates the Level of Service (LOS) at six (6) off-site
intersections. According to the report, all study intersections are expected to operate at LOS D or better
during the weekday PM peak hours in 2024 with or without the proposed project. Therefore, no project-
specific off-site transportation improvements are proposed as the existing transportation facilities are
anticipated to accommodate the additional traffic generated by the proposed project. Staff concurs with
the assessment provided by the applicant.
Staff determined that at completion of the project, the development will have met City of Renton
concurrency requirements (Exhibit 12), which is based upon a test of the citywide Transportation Plan,
consideration of growth levels included in the LOS-tested Transportation Plan, site specific improvements,
and future payment of Transportation Impact Fees. The transportation impact fee that is current at the
time of building permit issuance would be levied. It is anticipated that compliance with the City’s adopted
Street Standards and the payment of required Traffic Impact Fees would mitigate any adverse impacts
that could be generated by additional traffic attributed to the proposed subdivision; therefore, no further
mitigation is recommended.
Mitigation Measures: None recommended.
DocuSign Envelope ID: 88ED493A-1813-4C83-AC0E-63CD05982755
City of Renton Department of Community & Economic Development
Harmony Ridge
Staff Report to the Environmental Review Committee
LUA23-000143, ECF, PP, LLA, MOD
Report of October 30, 2023 Page 7 of 7
SR_ERC_Report_Harmony_Ridge_231025_FINAL
Nexus: Not applicable.
E. Comments of Reviewing Departments
The proposal has been circulated to City Department and Division Reviewers. Where applicable, their comments
have been incorporated into the text of this report and/or “Advisory Notes to Applicant.”
✓ Copies of all Review Comments are contained in the Official File and may be attached to this report.
The Environmental Determination decision will become final if the decision is not appealed within the 14 -day
appeal period (RCW 43.21.C.075(3); WAC 197-11-680).
Environmental Determination Appeal Process: Appeals of the environmental determination must be filed in writing
on or before 5:00 p.m. on November 13, 2023. Appeals must be submitted electronically to the City Clerk at
cityclerk@rentonwa.gov or delivered to City Hall 1st floor Lobby Hub Monday through Friday. The appeal fee,
normally due at the time an appeal is submitted, will be collected at a future date if your appeal is submitted
electronically. The appeal submitted in person may be paid on the first floor in our Finance Department. Appeals to
the Hearing Examiner are governed by RMC 4-8-110 and additional information regarding the appeal process may be
obtained from the City Clerk’s Office, cityclerk@rentonwa.gov.
✓
DocuSign Envelope ID: 88ED493A-1813-4C83-AC0E-63CD05982755
CITY OF RENTON
DEPARTMENT OF COMMUNITY AND ECONOMIC DEVELOPMENT
STAFF REPORT TO THE ENVIRONMENTAL REVIEW COMMITTEE
EXHIBITS
Project Name:
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Land Use File Number:
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Date of Meeting
October 30, 2023
Staff Contact
Alex Morganroth
Senior Planner
Project Contact/Applicant
Ivana Halverson
Barghausen Engineering
18215 72nd Ave S, Kent, WA
98032
Project Location
15509 116th Ave SE (2023059067)
The following exhibits are included with the ERC Report:
Exhibit 1: Environmental Review Committee (ERC) Report
Exhibit 2: SEPA Checklist
Exhibit 3: Site Plan
Exhibit 4: Plan Drawings (Drainage, Utility, Landscape)
Exhibit 5: Topography Map
Exhibit 6: Arborist Report, prepared by Washington Forestry Consultants, Inc, dated January 24,
2023
Exhibit 7: Tree Retention Worksheet
Exhibit 8: Geotechnical Engineering Study, prepared by Earth Solutions NW, LLC, dated
November 21, 2022, updated July 3, 2023
Exhibit 9: Preliminary Technical Information Report, prepared by Barghausen Engineers, dated
February 2, 2023
Exhibit 10: Wetland Reconnaissance, prepared by Altmann Oliver Associates, dated August 5, 2021
Exhibit 11: Traffic Impact Analysis, prepared by Transportation Engineering Northwest (TENW),
dated December 5, 2022
Exhibit 12: Transportation Concurrency Memo
Exhibit 13: Advisory Notes
Exhibit 14: Offsite Arborist Report, prepared by Washington Forestry Consultants, Inc, dated
August 7, 2023
DocuSign Envelope ID: 88ED493A-1813-4C83-AC0E-63CD05982755