HomeMy WebLinkAboutPN_Project Narrative 01-01-2023Level – I Drainage Report 01/01/2023 \PLE Project\Enclave\Preliminary Short Plat\Preliminary TIR
Project Narrative
Enclave
Preliminary 5 Lot Short Plat
January 1st, 2023
Existing Site Conditions and Hydrology,
The subject parcel is approximately 2.05 acres of developed land with King County Tax parcel ID number 1023059060
located at 980 Hoquiam Ave NE, Renton, WA 98059. The subject is zoned R-8 zoned and is bordered by existing fully
developed residential properties across its east and south boundary lines, by existing fully developed urban roadway
NE 10th Street across its north boundary line, and by existing fully developed urban roadway Hoquiam Ave. NE across
its west boundary line. The subject parcel is currently accessed directly off NE 10th Street via an existing concrete
driveway to be removed and is currently occupied by an existing Single-Family-Residence (SFR), existing car port, and
existing shed all to be removed (TBR). See attached Vicinity Map Exhibit – 1 for additional information.
According to the city of Renton and King County historic and current aerial photos for the subject parcel the site’s
ground cover has never been changed over past years since the build of the existing house in 1970 which includes
existing Category III Wetland in its southerly third and, existing trees along its westerly boundary, while the remaining
areas of the site are predominantly covered with SFR lawns (grass). See attached Site Aerial Photo Exhibit – 2 and
attached Site Photos Exhibit – 3 for additional information.
According to the site topographic (TOPO) Survey prepared by Tyee Surveyors the site existing topography is oriented
south and southeast with overall topographic relief of 10’ creating an overall grade slope of approximately 5%. Based
on our site visit and field reconnaissance dated October 24th, 2021 we observed no defined existing on-site stormwater
system within the subject parcel; and surface flows appear to sheet flow in south and southwesterly direction toward
the existing on-site Category III Wetland before existing the subject parcel in the easterly direction.
According to the city of Renton (COR) GIS information a small area of Regulated Slopes (existing road embankment)
does exist along westerly property line in the southwest portion of the project site. Also, according to the COR GIS
information, the site TOPO Survey, and Wetland Report dated May 26th, 2022 prepared by The Watershed Company a
Category III Wetland does exist in the southerly third of the subject parcel, see attached wetland report in the Special
Report Section of this Level – I Drainage Report, and see attached Regulated Slopes Map Exhibit – 4, Wetland Map
Exhibit – 5 for additional information.
The site soils were explored and tested and found to conducive to Limited Infiltration BMP, please refer to soil logs
information in the attached Geotechnical Report dated July 17, 2020 prepared by Nelson Geotechnical Associates in
the Special Reports Section of this Level – I Drainage Report.
According to COR GIS information the existing public utilities water, sewer, and storm systems do exist across the
subject parcel north and west property frontages in NE 10th Street and Hoquiam Ave. NE. See attached Existing
Utilities Exhibit – 6 for additional information.
See attached Existing Site Conditions Map Exhibit – 7 for additional information on existing site conditions.
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RESIDENTIAL COMMERCIAL GOVERNMENT
Bellevue, WA 98005 (425) 615 – 6160
info@pacificlandwa.com
Level – I Drainage Report 01/01/2023 \PLE Project\Enclave\Preliminary Short Plat\Preliminary TIR
Developed Site Conditions,
The project proposal is to sub-divide the subject parcel into 5 separate residential lots consistent with city of Renton
residential and density development regulation for R-8 zoned parcels.
Pursuant to COR Development Standards 4-2-110A for residential zoning designation, below is a list of proposed lots
area, building envelops aera, and setbacks:
Lot
Number
Total Lot
Area (sf)
Building Envelope
Area (sf)
Front Yard
Setback (ft)
Rear Yard
Setback (ft)
West Side Yard
Setback (ft)
East Side Yard
Setback (ft)
Lot – 1 5,647.03 2,241.90 20 20 15 5
Lot – 2 5,491.49 2,600.58 20 20 5 5
Lot – 3 5,460.65 2,574.97 20 20 5 5
Lot – 4 5,430.33 2,549.65 20 20 5 5
Lot – 5 5,490.21 2,575.05 20 20 5 5
As mentioned, a Category III Wetland exists in the southerly third portion of the subject site which is contained in a
recorded Critical Areas Tract – A encumbering total area of 31,127.18 square-feet. The classification of this wetland
mandates 75’ standard buffer pursuant to COR applicable regulation. However, the development proposal will include
reduction to this buffer by 25% down to 56.25’ and will provide wetland buffer reduction mitigation consistent with
said regulation. The reduced 56.25’ wetland buffer + the existing surveyed wetland limits will be set aside in a new and
larger Critical Area Tract-A encumbering total area of 61,054.63 s.f., see attached Civil Plans, attached density
calculations, and attached wetland mitigation report prepared by the Watershed Company dated May 26th 2022 for
additional information. See Exhibit – 8, Developed Site Conditions for additional information.
Per COR engineering staff inputs and pursuant to COR road standards / transportation code requirements, Section 4-6-
060 frontage right-of-way (ROW) dedication and road improvements are required in NE 10th Street and Hoquiam Ave
NE across the frontage of the subject parcel.
The attached boundary TOPO Survey prepared by Tyee Surveyors for the subject parcel shows existing road ROW and
existing road improvements in NE 10th Street across the frontage of the subject parcel already meet and exceed code
requirement per Section 4-6-060, and therefore no additional ROW dedication but at the request of city staff existing
sidewalk and planter strip across the property frontage will be removed and replaced with new 8’ wide planter strip
and 5’ wide concrete sidewalk but existing vertical curb and gutter will remain the same.
On the other hand, the proposed development will provide required ROW dedication and required road improvement
across the subject parcel frontage in Hoquiam Ave NE consistent with Section 4-6-060. This ROW dedication and
frontage road improvement will include:
Total 18’ wide paved road section measured from Hoquiam ROW centerline.
New 6” wide vertical concrete curb.
New 8’ wide planter strip.
New 5’ wide concrete sidewalk.
New 2’ ROW dedication.
See attached Civil Plans for additional information.
New water and sanitary sewer connections will be provided to each proposed lot directly off the existing public water
and sewer lines in NE 10th Street across the subject parcel frontage. See attached Utilities Connection Exhibit – 9 and
attached Civil Plans for additional information.
Please see Stormwater Compliance and Drainage Mitigation Section in this report.
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