The 2004 Comprehensive Plan designated South Lake Union as an urban center, and it laid out ambitious growth targets. Since then we’ve seen solid growth in the neighborhood through the Hutchinson Cancer Center, Amazon’s relocation, and of course the Seattle Streetcar. But the real potential for densification lies in incentivized upzones, and to that end the City of Seattle has released a draft Environmental Impact Statement, South Lake Union: Height and Density Alternatives. It studies the environmental impacts of three zoning alternatives that would create space for 23,000-31,500 jobs and 15,000-21,000 residences.
More after the jump…
Alternative 1 would bring the most comprehensive change, raising the maximum height limit to 400′ (for reference, 400′ is identical to the 37-story Aspira Tower at Stewart/Terry). The highest towers would be concentrated in a narrow area bounded by John, Denny, Aurora, and I-5, while the rest of the neighborhood would still see a rough doubling of the height limit, between 160-300′.
Alternative 2 would retain the current density in the Cascade-Fairview area (65-125′) while clustering the highest density (300′) into the western part of the neighborhood bounded by Mercer, Aurora, Westlake, and John.
Alternative 3 would offer the least densification, keeping the existing zoning in Cascade-Fairview while creating 85-240′ limits in the rest of the area.
These studies tend to be long-winded – at 659 pages this one doesn’t disappoint! – and I can’t possibly offer comprehensive comment. But a couple observations struck me. All three alternatives would bring major arterials into failing categories for auto traffic levels (LOS scores of D, E, and F), but since LOS scores are calculated relative to the prevailing speed limit, this tells me that increased density will simply slow things down to speeds common to a downtown core. As a pedestrian and cyclist who has braved Mercer I would welcome this, though as a transit rider stuck on Denny less so.
The report recommends significant improvements to bicycle/pedestrian facilities to mitigate the effects of growth. However, though the EIS is not intended to be a transit planning document, its assessment of potential transit investments is limited. The report mostly analyzes individual route load factors, and accordingly it focuses its recommendations on increasing headways rather than analyzing the route structure itself. Though it has an impressive list of bicycle, pedestrian, and roadway improvements, some of the worst stretches would receive little investment. For instance, Denny Way already fails all reliability standards (as anyone who rides Route 8 can attest!) but is largely overlooked for improvements, save for a pedestrian sidewalk on the north side of Denny over I-5 (between Stewart and Melrose). With ULink opening and Capitol Hill remaining an attractive place to live, Denny will be 60% over functional capacity under all 3 considered alternatives. It is clear that it will require significant investment, perhaps in the form of BAT lanes?
Anyway, there is much much more here, and public comment will be taken until April 11th. In the end I hope we will view this growth as an extension of the downtown core north from Westlake Center all the way to the lakeshore. It would be a shame if SLU upzones itself merely into an condo-and-office-park-writ-large. SLU has seen impressive growth, but it still lacks an evening and weekend pulse. There’s nowhere else in central Seattle so amenable to visionary infill development, so we really need to do this right.