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| New Boundary bridge spanning the scoured channel. Photo by Gary Paull |
The last Suiattle blog left us wondering about the delay to
repair the Suiattle River Road. This article tells the story of one
particularly unusual-looking bridge across the Suiattle and addresses one of the
many factors in the repairs to the Suiattle River Road, the inclusion of the
Suiattle in the Skagit Wild & ScenicRiver system (WSR). WSR designation preserves the free-flowing
attribute of selected rivers – these rivers will never be impounded.
Congressional wisdom enacted WSR as a counter –balance to its various actions
that allow dams and other constrictions on rivers.
Constructed
in 1959, the 240 foot-long Boundary Bridge spanned the entire river channel at
milepost 9.9, where FS 25 shoots off the Suiattle River Road, providing access
to the Circle Peak trail, Crystal and Meadow Lake trails, the Meadow Mountain
traverse, and tribal lands. The 2003 floods widened the river corridor and shifted
the river south, leaving the bridge 165 feet short, and the river flowing in
front of it, instead of underneath it.
After
the site was severely damaged in 2003, the Boundary Bridge repair work qualified
for funds from the Emergency Repair for Federally Owned Roads (ERFO). Projects in
the western region of Federal Highways that are funded by ERFO dollars are
managed by the Federal Highways Western Lands Division (FHWA), who work with
the land agency on those projects.
WSR
designation often requires special road and bridge design to maintain the river’s free flow, water
quality and other outstanding values, and Boundary Bridge was one such site. ERFO dollars pay for “in-kind” repair, meaning
putting things back the way they were. FHWA’s repair design included a the re-build
of a new riverbank to close in the 165-foot gap left by the 2003 floods – putting
back what Mother Nature had ripped out (that’s a lot of dirt!).
The Forest
Service did not agree with FHWA’s design, which had the potential to adversely
impact anadromous fish habitat and impair the river’s free-flowing attribute. Then
the November2006 floods shifted the dynamic river back to its original channel
underneath the bridge,changing the repair site once again. In 2007, the project
was put on hold and the excitement about the bridge repair fell silent.
In 2009, Peter Wagner, bridge engineer for the Mt.
Baker-Snoqualmie National Forest (see page 3 of the linked article), designed a bridge extension that addressed
the WSR specifications by utilizing a lightweight material so that a pier was
not necessary for support. Because the structural integrity of the original bridge was not compromised by
the floods, the old bridge was incorporated into the new design. The 210-foot
lightweight extension was “launched” from the end of the old bridge to the far
bank, and then heavy equipment was driven across to finish the job. The lightweight
material used for the extension means that we have an odd-looking bridge – part
1950s concrete, part new-age alloy with a high, criss-cross truss necessary for
strength and balance.
The Boundary
Bridge repair was completed in 2010, providing not only visual entertainment, but access to the south side of the
Suiattle for the first time since 2003.
Next time you're in the neighborhood, take the Suiattle River Road to milepost 9.9, and check out this bridge! (oh, and for the "it had to happen" files: there's a new washout on FS 25 at FS 2703. It's a nice drive across the Boundary Bridge - I like the way you sorta bounce onto the ramp at the new portion of the bridge)
Next up: What's the deal with the fish and Downey Creek?!



