Sound Transit set to finalize West Seattle & Ballard EIS alternatives

Link at Othello (Image: SounderBruce)

This afternoon, the Sound Transit Board will finalize the list of options to be examined in the Link Extensions Draft EIS for West Seattle and Ballard. A motion on the agenda adds just one more option in West Seattle to a initial list of alternatives adopted in May. Several other alternatives that were recently studied would not proceed any further. These include the Pigeon Point Tunnel in West Seattle and all of the options to locate a Ballard station near 20th Ave NW.

Let's recap how we reached this point. Sound Transit has been analyzing options for the Seattle ST3 lines since 2017. In May, the Board made a selection from those alternatives to be considered in the draft Environmental Impact Statement. In response to input received during the scoping period, the Board also directed staff to examine a half dozen other options that might also be added to the EIS. An initial analysis on those options was completed last month. With that information in hand, the Board now has to lock down the final list of options to go through the EIS process.

The Board may adopt further amendments at Thursday's meeting. If not, these are the project options that are will be studied in the EIS, or not:

In West Seattle, the motion on the agenda adds a potential elevated alignment along the Yancy/Andover corridor. That would be north of other alternatives in the mix, reducing the number of homes that would be taken for construction in the Youngstown area, but making Delridge station somewhat less accessible. Uniquely among the additional alternatives that might be added to the EIS, this wouldn't cost any more than the ST3 representative alignment.

Unlikely to proceed is a tunnel through Pigeon Point. The sticker price is $200 million, but it would also commit Sound Transit to build a $700 million tunnel to Alaska Junction. The tunnels at the Junction remain, independently, on the EIS options list. Apart from cost, a Pigeon Point tunnel would delay delivery of the project, perhaps by several years.

In West Seattle, an elevated alternative on Yancy/Andover is likely to be added to the EIS alternatives. Tunnels through Pigeon Point and to Alaska Junction are not. (image: Sound Transit)

In Ballard, the Board has already agreed to study three options that place a station around 14th or 15th Ave NW. These are a movable bridge crossing Salmon Bay west of the Ballard bridge to an elevated station at NW Market and 15th; a high fixed bridge with 14th elevated station; and a tunnel from near Interbay station to a Ballard tunnel station near 14th or 15th.

Two tunnel options serving 20th Ave NW in downtown Ballard would not proceed further. While the opportunity to have stations serving the more urban part of Ballard appeals to local advocates, Sound Transit staff expect no net increase in ridership from a more central location. Easier bus access to 14th/15th appears to roughly offset better walking access to 20th Ave. The 20th Ave options add $450-$750 million in costs compared to the representative alignment.

Two tunnel alternatives to downtown Ballard are not expected to proceed to the EIS (image: Sound Transit)

Also not likely to proceed are alternatives to elevate one or both of the lines through SODO. Elevating both would add $300 million in costs and require two months-long closures of the Rainier Valley Line. A "partial elevated" line wouldn't cost any more and would preserve the SODO busway, but adds local construction impacts. The option already in the draft EIS options places the new SODO station at grade west of the existing station with the new line in the E3 busway.

If Yancy/Andover is the only alternative added to the draft EIS, that would somewhat moderate increasing suburban nervousness about Seattle cost over-runs. Even without a Pigeon Point Tunnel or the more expensive Ballard options, it's still possible to add up a worst case where Seattle needs another $1.7 billion. With the full suite of options, it would be closer to $2.3 billion. Nobody has yet described a source of third-party funding for any of this, so continued pressure to remove the more high-priced options is certain.

On the other hand, Seattle board members have resisted efforts to choose the least-cost options, pointing to past compromises including vehicle crossings at grade in the Rainier Valley and the deferral of stations which are now being added back in ST3 at higher cost. The analogy is strained because the higher cost options they are pushing mostly mitigate neighborhood impacts rather improving transit riders' experience. Expect to hear this argument continued today.