As thousands from around Seattle visited the new 520 bridge over the weekend — waiting in amazingly long lines so long, officials had to close down the celebration’s shuttle runs early to better handle the crowds already in the middle of Lake Washington — a much, much smaller part of the massive construction project is moving forward to create a new community asset to enjoy the swath of nature preserved at the eastern base of Capitol Hill.
The Washington Park Arboretum has seen plenty of alterations since it was sketched to an Olmstead plan in the 1900s. Now, with $7.8 million in 520 construction mitigation funds from WSDOT, the rambling park/botanic collection is getting an enhancement that has been on the wish list for years: a 12-foot-wide paved path for walkers, wheelchairs, slow bikes, and strollers. The “slow” in “slow bikes” is operable — the path is to improve access to the plant collection and was designed with curves undesirable for your fast bike commute.
The SR 520 bridge is now open for traffic! Next weekend we'll close the bridge to begin shifting WB lanes onto the new bridge.
— SR 520 (@wsdot_520) April 3, 2016
Meanwhile, the new 520 — the “longest floating bridge in the world,” they say — is ready to open to traffic later this month. Watch for lots of planned closures of the crossing during the transition. Seattle’s western edge of the project including “a box girder style bridge including a bike and pedestrian path over Portage Bay, redesigned highway lids with a new land bridge, and multimodal connectivity improvements” remains under construction.
In the Arboretum, starting at the southern end of the Arboretum at 31st and Madison, the 1.2 mile path will proceed along the east side of Lake Washington Blvd. to Arboretum Drive through what is often a swampy valley with puddles. It will connect to the existing paved path to make an accessible, all-weather 2.5-mile loop. Construction has already started, and is scheduled for completion in December 2017.
Electric trams will run tours along the loop to provide additional accessibility. How frequently those tours will happen is to be determined, and “tram” is a somewhat misleading term.The quiet electric vehicles owned and operated by UW Botanic Gardens seat 13—and they’re more like large golf carts.
Improved accessibility will no doubt bring more people to the Arboretum, a prospect not all current users may welcome. But Seattle’s increasing density means an increased need for recreational opportunities as well as wildlife habitat and urban forests, says Sarah Reichard. She’s the director of the University of Washington Botanic Gardens, which owns and manages the Arboretum’s collection of trees and woody shrubs. Reichard says her department worked closely with Seattle Parks on the design of the trail to balance recreational purpose with environmental concerns. “Our highest priority has always been in maintaining the health of the collection here … The case for moving or removing every individual plant was carefully considered, and those that couldn’t be moved were propagated for reintroduction into the collection.” Reichard thinks that, by opening up areas that are currently inaccessible, the path may actually make the Arboretum feel bigger for some users.
The Loop Trail project involves daylighting parts of Arboretum Creek, which runs underground at some points. Those improvements will give the creek room to rise when there’s a lot of water draining into it, and bridges on the new path will allow park users a closer view. “You’re really going to know where Arboretum Creek is, once we’re done with this work,” says Garrett Farrell, senior capital projects manager for Seattle Parks.
It’s the first phase of what will be salmon-ready enhancements to the jigsaw of springs and hydrology flowing to Lake Washington through the Arboretum. “Right now, are we a salmon-bearing stream? No,” says Farrell. “But the protocols we’re using for this are the same as if we were trying to bring salmon back to Arboretum Creek … In addition, we’ve done work with the team to take the storm drainage off Lake Washington Boulevard—instead of putting it in a pipe and dumping it into the creek, you’ll see the curb opened up and bioswales build to kind of pre-treat that storm water runoff. Everything we’re doing here, and everything that we touch, is setting a stage for what could come in the future.”
Imagine that for an ecotopia. Azalea Walk and spawning salmon at the foot of Capitol Hill.
The park will remain open during construction, and the Japanese Garden will be unaffected. Seattle Parks’ press release says, “We may temporarily close or reroute some trails when work is taking place nearby.” It advises people to email firstname.lastname@example.org for construction updates.