The paper trail.

The 2019 SEPA checklist describes a project that keeps the block's existing drainage pattern rather than rerouting it: site and building runoff is gathered in area drains and catch basins and discharged into the public storm system in 106th Ave NE. From there it follows the path it already takes — west through 106th Ave NE storm laterals (generally 12-inch, with one 24-inch) into the 54-inch Meydenbauer storm-drain trunk main, which the applicant calls “non-capacity constrained,” running along NE 2nd Street, Bellevue Way NE and Main Street before discharging directly to Meydenbauer Bay, an arm of Lake Washington about 0.8 mile west.

On water quality, the checklist commits to managing stormwater from the new impervious surfaces per the 2017 City of Bellevue Storm and Surface Water Engineering Standards, and notes that “non-infiltrating bioretention planters” will be used to manage runoff on site. The “non-infiltrating” qualifier is the operative detail: because the block sits over a state-supervised solvent plume and dense glacial till, the planters are lined so runoff doesn't soak into the ground.

The impervious-cover math is why the filing treats flow control lightly: the site is already about 98% impervious (~171,311 sf, the pre-demolition block being largely surface parking), and the towers-on-a-podium scheme actually drops that to about 95% (~166,662 sf) as plazas and landscaping replace asphalt. Two regulatory backstops still apply: City stormwater review under Bellevue's NPDES Phase II municipal permit (Meydenbauer Bay drains to Lake Washington), and a state Construction Stormwater General (NPDES) permit from Ecology governing discharges during the deep excavation.

The single hardest number in the project's environmental record is the dirt: the 2019 SEPA checklist puts overall excavation at roughly 356,853 cubic yards, with only minimal fill brought back. The checklist never tallies the resulting truck trips, so the count is an estimate, not a project figure — but the arithmetic is unavoidable. At roughly 12–15 cubic yards per loaded tandem dump truck, that volume works out to on the order of 24,000–30,000 loaded truckloads over the life of the dig (a wider plausible range is ~20,000–36,000), each a round trip on city streets. Some spoil is not clean fill: the record flags a likely abandoned heating-oil tank under the old Belle Lanes and a migrated dry-cleaning-solvent (PCE) plume, with any contaminated soil removed to permitted off-site disposal under state and local rules.

Where those trucks may drive is constrained by city code. The block fronts 106th Avenue NE between NE 6th and NE 8th Streets, but 106th is not one of Bellevue's designated truck routes: under Bellevue City Code 11.70.060, trucks over eight feet wide, 30 feet long, or 32,000 pounds — plus anything carrying hazardous cargo — are confined to the state highway system or a short list of authorized routes, which on this side of downtown run along 108th and 112th Avenues NE rather than 106th. In practice loaded haul trucks are expected to reach a designated route or I-405 by the most direct path.

Bellevue handles that through right-of-way permitting. Hauling, parking and staging in the public right-of-way require a Commercial Right-of-Way Use permit, and a Traffic Control Plan is a required submittal — the document in which haul routes, lane and sidewalk closures and flagging are spelled out and approved by the city. Standard conditions keep abutting businesses and residents accessible and bar closing the sidewalks on both sides of a block at once. Dust and tracking are addressed on the environmental side: the checklist commits to Puget Sound Clean Air Agency dust rules and sprinklering during demolition and to a Temporary Erosion and Sedimentation Control plan.

The June 2022 Master Development Plan and Design Review approval (19-104024-LP & 19-104023-LD) came with conditions that shape the project in detail. The city granted five Administrative Departures from the Land Use Code under LUC 20.25A.030.D, all approved: a build-to-line departure, a compact-parking departure, planter strips in lieu of tree pits, a weather-protection departure, and a reduction in required open space. The compact-parking departure let the design use 61% compact stalls (about 1,517) against a 65% code maximum. The open-space departure shaved the on-site public plaza from the code-required 10% of the site (17,491 sf) to 9.75% (17,069 sf) — justified because the project already dedicates a Major Public Open Space and a 30-foot Grand Connection segment; counting all plaza types, the staff report says it provides over 43,177 sf, about 25% of the site.

Several conditions lock in public access in perpetuity: Onni must record legal agreements with King County guaranteeing 24-hour public access within the 30-foot Grand Connection section (condition 40), the Major Public Open Space (condition 41), and the east–west through-block pedestrian connection (condition 39, which also requires directional signage at every access point), plus a public-access easement keeping the outdoor plazas "open to the public at all times" (condition 42).

The reason those agreements are mandatory rather than voluntary lies in Bellevue's Amenity Incentive System: under LUC 20.25A.175, any property within the Grand Connection or a Major Public Open Space must be placed under a recorded agreement granting the public a "nonexclusive right of pedestrian use and access" — an obligation tied to earning bonus floor-area ratio through LUC 20.25A.070, executed before a certificate of occupancy issues. A separate condition (47) grants no signage approvals up front: before any occupancy, tenant-improvement or sign permit, Onni must submit a complete sign package consistent with Bellevue City Code 22B.10, with signs forming "an integral part of the overall architectural design."

The project's transportation review runs deeper than the headline trip count. Transpo Group's Traffic Impact Analysis (November 20, 2020) evaluated six intersections — Bellevue Way NE/NE 8th, 106th Ave NE at NE 8th, NE 4th and NE 6th, 108th Ave NE/NE 8th, and Lincoln DW/NE 8th — and the city found all would remain at level of service E or better with the project's improvements in place. For Bellevue's concurrency test under the Traffic Standards Code (BCC 14.10), the project was modeled at roughly 1,356 new PM-peak trips and assigned via the city's EMME-2 model; all 14 Mobility Management Areas met their standards, so it received a Certificate of Concurrency. The 1,356 concurrency figure is lower than the 1,741 gross PM-peak generation total — the record doesn't explain the gap, but it likely reflects pass-by and internal-capture credits.

The underlying trip-generation memo (Transpo Group, January 9, 2019) built the 1,741 figure from Bellevue impact-fee trip rates, by use: office 919 trips, residential 533, retail and food court 137, hotel 107, daycare 93 and restaurant 42, minus credits for the existing retail (68) and church (22) removed. The daycare's 12.34 trips per 1,000 sf is the highest per-square-foot rate of any use. (One wrinkle: the trip memo modeled a rounded "1,300 dwellings," slightly above the 1,289-unit count cited elsewhere in the same filing.) Because the code carries no parking ratio for hotel, daycare or fitness, Transpo prepared dedicated demand studies — the hotel at 0.55 vehicles per occupied room (141 vehicles for 257 rooms), the daycare at 0.24 per student (12 vehicles for 52 students), and the gym via a separate March 2021 Fitness Center Parking Analysis.

As mitigation, the approval requires Onni to widen 106th Ave NE along its frontage to a future 56-foot, five-lane cross-section up to NE 8th St, with a minimum 15-foot sidewalk separated by a 5-foot planter strip and a rebuilt transit stop. The site provides thirteen off-street loading stalls — twelve sized for an SU-30 truck and one for a WB-40 semi — fed from a shared east-side service lane that also serves loading and refuse for the neighboring Symetra and Key Center towers, which hold an access easement across the block. Non-freight access is separate: a daycare drop-off on Level 0 and a 150-foot rideshare/drop-off pullout on Level 1, with plan sheets explicitly labeling "Uber drop-off" zones. Before initial occupancy the owner must record a city-approved Transportation Management Program under BCC 14.60.070, and pays Bellevue transportation impact fees at building-permit issuance.

The entire Onni 606 site is carried by the King County Assessor as a single consolidated parcel, 154410-0214, with a situs address of 680 106th Ave NE and a lot size of 174,913 square feet (about 4.02 acres). The Assessor lists the taxpayer of record as ONNI 106TH AVE BELLEVUE LLC, still under the legacy name “Barnes and Noble Bookstore and Doxa John Danz Building.”

For the 2025 valuation (2026 tax year) the Assessor sets the total appraised value at $139,931,400 — $139,930,400 of it land and just $1,000 improvements, so almost the entire assessed value sits in the land. The total has held flat at $139,931,400 across the 2024–2026 tax years, up from $135,558,500 for 2023.

A land base of roughly $140 million implies a sizable annual property-tax obligation — on the order of $1 million at Bellevue's commercial levy rates — though the exact billed amount is published separately by King County Treasury. As the towers rise, expect the improvement value (now $1,000) to climb sharply in future assessment rolls.

The single consolidated parcel was legally created by a City of Bellevue Boundary Line Adjustment: the Assessor's legal description reads "CHERITON FRUIT GARDENS PLAT #1 PCL '1' OF BELLEVUE BLA #19-104027 LW REC #20210315900014" — Parcel 1 of BLA file 19-104027-LW, recorded March 15, 2021, which folded the block's formerly separate lots into one development parcel (the previously separate 620 106th Ave NE parcel, 154410-0217, now returns no Assessor data, consistent with the merger). The 2019 acquisition is recorded as a bargain-and-sale deed under King County excise number 2973252, dated February 12, 2019, transferring title from Sterling Realty Organization Co. for $116,000,000. On financing, the DJC reported in June 2026 that "just over a year ago, Wells Fargo agreed to provide a $53.5 million loan to Onni" — placing it around mid-2025 and framed as money to "help get the job started," so it reads as an early-works or predevelopment facility rather than the full construction loan a build of this scale will ultimately require.