HomeMy WebLinkAboutERC_DS_Memo_Longacres_FINAL
DATE: June 2, 2025
TO: Environmental Review Committee (ERC)
FROM: Jill Ding, Senior Planner
SUBJECT: Longacres Campus Master Plan, LUA25-000100, SA-M, ECF
This memorandum is intended to provide the ERC with a short project description and
staff’s recommendation for an Environmental Determination for the subject project.
Project Description
The applicant, Unico Properties, is requesting Hearing Examiner Master Plan Review and
Environmental (SEPA) Review to develop the Longacres Campus into a mixed-use
development. The Longacre Site totals approximately 158 acres and includes
approximately 850,000 square feet of existing office space, maintenance buildings, and
landscaped area. The proposed project site would include approximately 85 acres of the
main campus area. The project site is zoned Commercial Office (CO) and Medium
Industrial (IM) and is located within Urban Design District D and the Employment Area (EA)
Comprehensive Plan Land Use Designation. The proposal would retain approximately
330,000 square feet of existing commercial space on the site and add approximately 3,000
new residential units, approximately 1,400,000 square feet of future commercial and
medical office, approximately 230,000 square feet of industrial uses, approximately
100,000 square feet of retail, food and beverage, two (2) hotel sites (with approximately
150-200 rooms), and an 8,000-person music venue. The plan proposes to demolish the
existing building on parcel 7 for a future music venue. The plan proposes to build
approximately 6,500 parking stalls to support the site uses. The proposed project site
consists of 18 separate parcels (APNs 088670-0010, -0020, -0030, -0040, 0050, -0060, -
0070, -0080, -0120, -0130, -0140, -0200, -0210, -0220, -0230, -0250, -0360, and 242304-
9050) located at 1301 SW 16th St and 1901 Oakesdale Ave SW. In addition, the overall site
includes three (3) industrial parcels that provide the power, heat, and cooling (APNs
2423049071, -9052, and -9048) located at 1300 and 1302 SW 16th St. According to City of
Renton (COR) Maps, the site is mapped with high seismic hazard areas, special flood
hazard areas (100-year flood) FEMA Zone AE, regulated shorelines, regulated slopes, and
wetlands. It is anticipated that additional permit applications would be submitted in the
future as the project proposal is further refined.
Docusign Envelope ID: 0E0D12C8-0EC8-4844-8E89-1AB93093165B
Longacres Campus Master Plan, LUA25-000100, SA-M, ECF
Page 2 of 3
June 2, 2025
Environmental Threshold Recommendation
Based on analysis of probable impacts from the proposal, staff recommends that the
Responsible Officials:
Issue a Determination of Significance (DS) with a 14-day Appeal Period.
Staff anticipates that the subject project may have a probable significant impact based on
the project’s size, scope and intensity of the proposed use, which could result in significant
impacts to Earth, Air, Water, Critical Areas, Environmental Health – Noise, Recreation,
Historic and Cultural Preservation, and Transportation. Because the proposal is likely to
have a significant adverse environmental impact, an EIS would be required (WAC 197-11-
310 and 197-11-360).
The proposed development would be expected to address in varying degrees, including but
not limited to, the following environmental issues:
• A Preliminary Geotechnical Engineering Services report, prepared by GeoEngineers,
Inc., dated September 26, 2024 (Exhibit 1), submitted with the project application
materials indicates that the onsite soils consist of alluvium and potentially
liquifiable soils. In addition, onsite groundwater levels are anticipated to fluctuate
and may be near the ground surface during the wet season.
• A Critical Areas Report, prepared by Pace Engineers, dated January 2025 (Exhibit 2),
submitted with the project application identified the presence of three (3) large
wetlands and one (1) detention pond (Wetland A, Wetland G, and Pond B) and one
(1) smaller wetland (Wetland F). Wetland A, Pond B, and Wetland F are located on
the west side of Oakesdale Ave SW. Wetland G and Springbrook Creek are located
on the east side of Oakesdale Ave SW. Springbrook Creek is located outside the
study area and was not delineated. In addition, various stormwater features are
also present on the site. Springbrook Creek, designated as a Shoreline of the State
and subject to the Shoreline Management Act, is located within the high intensity
shoreline environment designation, is approximately 456 feet (456’) to the northeast
of Wetland F, and an average of about 220 feet (220’) to the east of Wetland G. The
shoreline setback and floodplain for the creek extends onto the site.
• A Trip Generation and EIS Traffic Analysis Scoping Memorandum, prepared by
TENW, dated January 31, 2025 (Exhibit 3), submitted with the project application
indicates that the proposed Alternative 2 development would be anticipated to
generate approximately 22,115 daily trips, 1,678 AM peak hour trips, and 2,090 PM
peak hour trips, potentially significantly reducing the LOS at many intersections
within the project vicinity.
• Additional concerns include potential impacts to archaeological resources that
may be located onsite.
Exhibits
Exhibit 1: Preliminary Geotechnical Engineering Services, prepared by GeoEngineers, Inc.,
dated September 26, 2024
Docusign Envelope ID: 0E0D12C8-0EC8-4844-8E89-1AB93093165B
Longacres Campus Master Plan, LUA25-000100, SA-M, ECF
Page 3 of 3
June 2, 2025
Exhibit 2: Critical Areas Report, prepared by Pace Engineers, dated January 2025
Exhibit 3: Trip Generation and EIS Traffic Analysis Scoping Memorandum, prepared by
TENW, dated January 31, 2025
Docusign Envelope ID: 0E0D12C8-0EC8-4844-8E89-1AB93093165B