Thursday, September 3, 2020

One more SR 202 closure for culvert replacement coming up

By Tom Pearce

One down, one to go.

Just west of Fall City, a second closure of State Route 202 between Southeast 31st Street and West River Road is scheduled for the weekend of Sept. 12-13. In late August we closed the highway closer to Sammamish to replace a culvert that carries Patterson Creek under the highway.

This next closure allows us to replace a couple of culverts keeping salmon and other fish from continuing upstream. From 9 p.m. Friday, Sept. 11 to 5 a.m. Monday, Sept. 14, the road will be closed and all traffic will follow a signed detour. The route is fairly narrow, so truck traffic will need to use I-90, I-405 and SR 520 to get around the closure.
The culverts being replaced under SR 202 carry unnamed tributaries to Patterson Creek. They are narrow and water often moves too fast through them for fish to continue upstream.

Why a full closure?

The stretch of SR 202 near these culverts is relatively narrow at this location, which makes it impossible to keep a lane open during culvert replacement. 

During the full highway closure, our contractor crews will dig up both culverts and replace them with larger box culverts. These will be able to carry natural creek beds, which will make it easy for fish and other marine life to move up and downstream. It's all part of our effort to improve fish passage under state highways, which will help increase fish populations in Puget Sound.

Patterson Creek culvert complete

During the last weekend of August, it took us about 55 hours to replace the culvert for Patterson Creek just east of Sammamish. Similar to what we will be doing during the Sept. 12-13 closure, we had to dig up the old culvert from about 10 feet beneath the roadway. Then we put in a new, larger structure and paved a new roadway back on top.

Replacing these culverts will open up about 11½ miles of additional habitat for salmon and resident fish. That's more area to spawn and for young fish to grow.
Crews lift a section of concrete culvert into place at Patterson Creek.

Improving salmon habitat

Opening up culverts and improving waterways means more species will be able to make the journey to spawning grounds and expanded rearing habitat for young fish. 

By the year 2030, we plan to replace hundreds more fish barriers under our highways. In some cases the narrow passages need to be widened. In other locations, creek levels have dropped, creating too large of a jump for migratory fish to make. 

We appreciate your patience not just with the culvert removals happening this month under SR 202, but with all our future fish passage projects in the years to come.

2 comments:

Unknown said...

Wow. Fish.

Unknown said...

Cannot imagine how fish found millions of human dollars to spend on road projects.

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