More than 14,000 times per year, the Seattle Department of Transportation safely raises and lowers its drawbridges, even though three of them are a century old.

This minor miracle requires constant maintenance work, to serve a city that lacks the money and plans to replace its old bridges anytime soon.

The Seattle Department of Transportation (SDOT) has identified about $7.8 million worth of urgent projects to keep the Ballard, Fremont and University steel-deck bridges, and the Spokane Street swing bridge, reliable for marine openings.

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The agency compiled the list at the request of Seattle City Councilmember Alex Pedersen, who toured the University Bridge last month with SDOT roadway structures director Matt Donahue.

For several years, council members have hesitated to pour large amounts of money into bridge preservation, favoring other transportation services and safety work.

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“The very least they could do is replace the aging components that prevent our movable bridges from breaking down,” Pedersen said. “The cost is only $8 million to replace those vital parts and I believe it’s a wise investment to make sure we don’t have another bridge out of commission.”

Bridge maintenance grabbed the council’s attention in March 2020, when fast-growing cracks forced SDOT to close the West Seattle Bridge for two years while repairs are made. Before that, the 104-year-old Ballard Bridge stuck open twice in December 2019.

An audit last year found at least $34 million a year should be devoted to maintain the city’s 124 bridges, whose replacement value is $6.9 billion. Seattle spent only $6.6 million annually this past decade, but boosted that to $9.5 million in 2021.

SDOT’s project list calls for new drawbridge lift motors “for which replacement parts are no longer available,” engineering investigations to assure the steel spans balance properly when raised and new hydraulic drives to turn the pivoting Spokane Street bridge.

The rough $7.8 million figure doesn’t include design, management and contingency costs that could bring the total near $10.2 million, spokesman Ethan Bergerson said.

Pedersen, who chairs the council’s Transportation and Utilities Committee, proposed using $20 in car-tab fees to boost bridge maintenance by $7.2 million per year. His plan was co-sponsored by Councilmembers Andrew Lewis, whose district includes the Ballard Bridge, and Lisa Herbold, of West Seattle. A thin majority balked, so that money will be divided by a subcommittee for uses not yet decided.

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A year of car-tab fees “could potentially pay for everything on the list,” Lewis said Tuesday.” I think we have a looming infrastructure crisis in the city when it comes to bridges.”

Beyond that, he said bonds could be sold off the car-tab revenue, giving SDOT tens of millions of dollars to combine with any Biden administration federal infrastructure grants. The city would be in better position to replace the Ballard or Magnolia bridges, or increase transit and safety programs, Lewis said.

Pedersen has suggested developer-impact fees for bridge improvements, which Seattle doesn’t charge but are used in 79 other Washington cities.

Last week, Pedersen proposed steering some of the city’s $230 million federal pandemic relief grants into city bridges. Council talks began Tuesday regarding those grants, with transportation listed among nine priorities, competing with food aid, rental assistance and other needs.

Meanwhile, SDOT recently completed seismic reinforcement of the West Howe Street bridge over Magnolia Park, with nine more projects by 2025. This summer, the city will reopen a new Fairview Avenue North bridge, which formerly sat on timber pilings.

On a partly-sunny Monday, the University Bridge’s steel decks opened then lowered at the stroke of 9 a.m., inaudible under the noise cloud of Interstate 5 nearby.

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The traffic decks and sidewalks need new gate arms, Donahue said. “They work, but they go out all the time. It’s full of hard-to-replace parts.”

He unlocked a door to a dark staircase that leads to the electric motor room and a catwalk under the decks. From there you see the dark-green teeth of mammoth gear wheels — one for each side of the folding decks.

Those are still solid, based on ultra-fluorescent testing that showed no hidden defects, Donahue said. New motor-control circuits were installed in 2014, but the Ballard Bridge still relies on computer components from the early 1980s.

The University Bridge, built in 1919 and mostly rebuilt in 1930, is rated “poor” in the National Bridge Inventory because of old support columns. Additional funds, beyond the $7.8 million, are needed sooner or later to solve that weakness.

For instance, directly over the north canal shore, a large concrete column has a vertical gouge where steel rebar shows through. That spot requires fixing, and rock riprap probably will be needed below to prevent erosion near water level, Donahue said. Road decks and drawspans are in good condition, though.

“You know me,” he said. “I would rather rehab than replace.”