Snohomish County’s bridges are safe, but some still need work

GRANITE FALLS — You won’t get your feet wet.

“All the bridges are safe. If they’re open for traffic, they’re safe. And safety of the public is always the highest priority,” said Charlie Green, engineering design manager.

Still, there are several bridges over Snohomish County rivers and creeks that engineers would like to replace. Rushing rivers and rush-hour traffic are among the reasons.

The biggest challenge is finding the money for the multi-million dollar projects.

Snohomish County recently released an annual report on its bridges. It details work done in 2017 and projects coming up. It also has a to-do list waiting for funding, with some familiar names.

A prime example is Granite Falls Bridge 102, a span over the South Fork Stillaguamish River on the way to the Mountain Loop Highway, about 1½ miles northeast of downtown. The county each year seeks federal bridge funds for what it estimates will be a $22 million rebuild. They already have the type of bridge, materials and right of way nailed down. But this year’s grant request, which would complete the design and construction phases, again fell short.

“There’s lots of other agencies competing for the money,” Green said.

The county has been good at winning those dollars in the past. Out of over 200 bridges, 71 have been replaced since 1994. The county has gone from having 90 percent of its bridges being made primarily from the timber of surrounding forests to 19 percent.

“We’re getting to not as many compelling bridge stories,” Green said.

Especially when those dollars hinge on specific criteria.

Also high on the list is the 64-year-old Red Bridge 537 on the Mountain Loop Highway. The bridge spans the South Fork Stillaguamish east of Verlot.

Dive teams were out again last summer. One pier in particular has felt the river’s scouring effects. But the bridge itself does not meet the federal government’s definition of being structurally deficient. And a funding request in 2017 failed again.

“I was sure that was going to get funded last year, and I was terribly disappointed that it didn’t,” county bridge engineer Darrell Ash said.

Three county-owned bridges are classified as structurally deficient — when a bridge is most likely to get federal help — and grant money is in hand for one of them.

The 1930-built Riley Slough Bridge 155, on Tualco Road near Monroe, will be replaced in 2019.

Trout Creek Bridge 494 near Index is getting some preliminary design work. It was built in 1946. Engineers are eyeing a single-span replacement that would remove support piers from the creek, helping reduce the accumulation of debris. This summer, crews will take off the top four inches of asphalt from the existing bridge deck to ease the weight on the piers.

A grant request to rebuild Black Creek Bridge 547 was turned down earlier this year. The 66-year-old bridge on the Mountain Loop Highway has rotten piles and pile caps, and the water has scoured at the shallow concrete footings.

“That’s one we’re just continuing to inspect and monitor to make sure it remains safe,” Green said.

Also getting attention this summer is Swamp Creek Bridge 503, near Brier. The 58-year-old bridge has timber parts that are showing their age. It’s also narrow, with no shoulders or sidewalks. The county is doing some survey and soil work to get started on a replacement.

But it’s more than water that wears on bridges.

Snohomish County is growing, and bridges often feel the squeeze.

An example is Richardson Creek Bridge 300, a short bridge built in 1961 on Woods Creek Road near Monroe. It’s classified as functionally obsolete — it’s structurally sound; but its narrow width and high traffic volume mean it’s no longer fit for its job.

Big federal bridge grants aren’t available for such short spans. But the county did secure a different federal grant and is preparing to replace the bridge. Construction could happen in 2021. The total could come in around $2 million, Green estimated.

When it’s done, the bridge will be wider and longer.

It will be ready for the future, Green said, when Woods Creek Road itself could be widened to include space for bicycles and pedestrians. Of course, that will take money, too.

Melissa Slager: streetsmarts@heraldnet.com, 425-339-3432.

Learn about bridges

Read the county’s recently released 2017 Annual Bridge Report online at tinyurl.com/2017BridgeReport.